--- /dev/null
+diff -ruN linux-2.4.19-rc1/include/linux/fs.h linux/include/linux/fs.h
+--- linux-2.4.19-rc1/include/linux/fs.h Tue Feb 19 15:24:57 2002
++++ linux/include/linux/fs.h Thu Feb 21 12:34:42 2002
+@@ -260,7 +260,10 @@
+ char * b_data; /* pointer to data block */
+ struct page *b_page; /* the page this bh is mapped to */
+ void (*b_end_io)(struct buffer_head *bh, int uptodate); /* I/O completion */
+- void *b_private; /* reserved for b_end_io */
++ void *b_private; /* reserved for b_end_io, also used by ext3 */
++ void *b_bdev_private; /* a hack to get around ext3 using b_private
++ * after handing the buffer_head to the
++ * block layer */
+
+ unsigned long b_rsector; /* Real buffer location on disk */
+ wait_queue_head_t b_wait;
--- /dev/null
+diff -ruN linux-2.4.19-rc1/drivers/md/Config.in linux/drivers/md/Config.in
+--- linux-2.4.19-rc1/drivers/md/Config.in Fri Sep 14 22:22:18 2001
++++ linux/drivers/md/Config.in Wed Jan 2 19:23:58 2002
+@@ -14,5 +14,8 @@
+ dep_tristate ' Multipath I/O support' CONFIG_MD_MULTIPATH $CONFIG_BLK_DEV_MD
+
+ dep_tristate ' Logical volume manager (LVM) support' CONFIG_BLK_DEV_LVM $CONFIG_MD
++if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
++ dep_tristate ' Device-mapper support (EXPERIMENTAL)' CONFIG_BLK_DEV_DM $CONFIG_MD
++fi
+
+ endmenu
+diff -ruN a/Documentation/Configure.help b/Documentation/Configure.help
+--- linux-2.4.19-rc1/Documentation/Configure.help Tue Jun 25 14:14:05 2002
++++ linux/Documentation/Configure.help Tue Jun 25 19:18:26 2002
+@@ -1775,6 +1775,18 @@
+ want), say M here and read <file:Documentation/modules.txt>. The
+ module will be called lvm-mod.o.
+
++Device-mapper support
++CONFIG_BLK_DEV_DM
++ This option lets you create logical block devices dynamically by
++ joining together segments of existing block devices. This mechanism
++ is used by the new version of the logical volume manager under
++ development, LVM2.
++
++ If you want to compile this as a module, say M here and read
++ <file:Documentation/modules.txt>. The module will be called dm-mod.o.
++
++ If unsure, say N.
++
+ Multiple devices driver support (RAID and LVM)
+ CONFIG_MD
+ Support multiple physical spindles through a single logical device.
--- /dev/null
+diff -ruN linux-2.4.19-rc1/drivers/md/Makefile linux/drivers/md/Makefile
+--- linux-2.4.19-rc1/drivers/md/Makefile Tue Jun 25 22:14:21 2002
++++ linux/drivers/md/Makefile Tue Jun 25 22:09:23 2002
+@@ -4,9 +4,10 @@
+
+ O_TARGET := mddev.o
+
+-export-objs := md.o xor.o
++export-objs := md.o xor.o dm-table.o dm-target.o
+ list-multi := lvm-mod.o
+ lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
++dm-mod-objs := dm.o dm-table.o dm-target.o
+
+ # Note: link order is important. All raid personalities
+ # and xor.o must come before md.o, as they each initialise
+@@ -20,8 +21,12 @@
+ obj-$(CONFIG_MD_MULTIPATH) += multipath.o
+ obj-$(CONFIG_BLK_DEV_MD) += md.o
+ obj-$(CONFIG_BLK_DEV_LVM) += lvm-mod.o
++obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
+
+ include $(TOPDIR)/Rules.make
+
+ lvm-mod.o: $(lvm-mod-objs)
+ $(LD) -r -o $@ $(lvm-mod-objs)
++
++dm-mod.o: $(dm-mod-objs)
++ $(LD) -r -o $@ $(dm-mod-objs)
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-table.c linux/drivers/md/dm-table.c
+--- linux-2.4.19-rc1/drivers/md/dm-table.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-table.c Tue Jun 25 22:02:56 2002
+@@ -0,0 +1,421 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++
++#include <linux/blkdev.h>
++
++/* ceiling(n / size) * size */
++static inline unsigned long round_up(unsigned long n, unsigned long size)
++{
++ unsigned long r = n % size;
++ return n + (r ? (size - r) : 0);
++}
++
++/* ceiling(n / size) */
++static inline unsigned long div_up(unsigned long n, unsigned long size)
++{
++ return round_up(n, size) / size;
++}
++
++/* similar to ceiling(log_size(n)) */
++static uint int_log(unsigned long n, unsigned long base)
++{
++ int result = 0;
++
++ while (n > 1) {
++ n = div_up(n, base);
++ result++;
++ }
++
++ return result;
++}
++
++/*
++ * return the highest key that you could lookup
++ * from the n'th node on level l of the btree.
++ */
++static offset_t high(struct dm_table *t, int l, int n)
++{
++ for (; l < t->depth - 1; l++)
++ n = get_child(n, CHILDREN_PER_NODE - 1);
++
++ if (n >= t->counts[l])
++ return (offset_t) - 1;
++
++ return get_node(t, l, n)[KEYS_PER_NODE - 1];
++}
++
++/*
++ * fills in a level of the btree based on the
++ * highs of the level below it.
++ */
++static int setup_btree_index(int l, struct dm_table *t)
++{
++ int n, k;
++ offset_t *node;
++
++ for (n = 0; n < t->counts[l]; n++) {
++ node = get_node(t, l, n);
++
++ for (k = 0; k < KEYS_PER_NODE; k++)
++ node[k] = high(t, l + 1, get_child(n, k));
++ }
++
++ return 0;
++}
++
++/*
++ * highs, and targets are managed as dynamic
++ * arrays during a table load.
++ */
++static int alloc_targets(struct dm_table *t, int num)
++{
++ offset_t *n_highs;
++ struct target *n_targets;
++ int n = t->num_targets;
++
++ /*
++ * Allocate both the target array and offset array at once.
++ */
++ n_highs = (offset_t *) vcalloc(sizeof(struct target) + sizeof(offset_t),
++ num);
++ if (!n_highs)
++ return -ENOMEM;
++
++ n_targets = (struct target *) (n_highs + num);
++
++ if (n) {
++ memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
++ memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
++ }
++
++ memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
++ if (t->highs)
++ vfree(t->highs);
++
++ t->num_allocated = num;
++ t->highs = n_highs;
++ t->targets = n_targets;
++
++ return 0;
++}
++
++int dm_table_create(struct dm_table **result)
++{
++ struct dm_table *t = kmalloc(sizeof(*t), GFP_NOIO);
++
++ if (!t)
++ return -ENOMEM;
++
++ memset(t, 0, sizeof(*t));
++ INIT_LIST_HEAD(&t->devices);
++
++ /* allocate a single node's worth of targets to begin with */
++ if (alloc_targets(t, KEYS_PER_NODE)) {
++ kfree(t);
++ t = NULL;
++ return -ENOMEM;
++ }
++
++ init_waitqueue_head(&t->eventq);
++ *result = t;
++ return 0;
++}
++
++static void free_devices(struct list_head *devices)
++{
++ struct list_head *tmp, *next;
++
++ for (tmp = devices->next; tmp != devices; tmp = next) {
++ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
++ next = tmp->next;
++ kfree(dd);
++ }
++}
++
++void dm_table_destroy(struct dm_table *t)
++{
++ int i;
++
++ /* destroying the table counts as an event */
++ dm_table_event(t);
++
++ /* free the indexes (see dm_table_complete) */
++ if (t->depth >= 2)
++ vfree(t->index[t->depth - 2]);
++
++ /* free the targets */
++ for (i = 0; i < t->num_targets; i++) {
++ struct target *tgt = &t->targets[i];
++
++ dm_put_target_type(t->targets[i].type);
++
++ if (tgt->type->dtr)
++ tgt->type->dtr(t, tgt->private);
++ }
++
++ vfree(t->highs);
++
++ /* free the device list */
++ if (t->devices.next != &t->devices) {
++ DMWARN("devices still present during destroy: "
++ "dm_table_remove_device calls missing");
++
++ free_devices(&t->devices);
++ }
++
++ kfree(t);
++}
++
++/*
++ * Checks to see if we need to extend highs or targets.
++ */
++static inline int check_space(struct dm_table *t)
++{
++ if (t->num_targets >= t->num_allocated)
++ return alloc_targets(t, t->num_allocated * 2);
++
++ return 0;
++}
++
++/*
++ * Convert a device path to a kdev_t.
++ */
++int lookup_device(const char *path, kdev_t *dev)
++{
++ int r;
++ struct nameidata nd;
++ struct inode *inode;
++
++ if (!path_init(path, LOOKUP_FOLLOW, &nd))
++ return 0;
++
++ if ((r = path_walk(path, &nd)))
++ goto bad;
++
++ inode = nd.dentry->d_inode;
++ if (!inode) {
++ r = -ENOENT;
++ goto bad;
++ }
++
++ if (!S_ISBLK(inode->i_mode)) {
++ r = -EINVAL;
++ goto bad;
++ }
++
++ *dev = inode->i_rdev;
++
++ bad:
++ path_release(&nd);
++ return r;
++}
++
++/*
++ * See if we've already got a device in the list.
++ */
++static struct dm_dev *find_device(struct list_head *l, kdev_t dev)
++{
++ struct list_head *tmp;
++
++ list_for_each(tmp, l) {
++ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
++ if (dd->dev == dev)
++ return dd;
++ }
++
++ return NULL;
++}
++
++/*
++ * Open a device so we can use it as a map destination.
++ */
++static int open_dev(struct dm_dev *d)
++{
++ int err;
++
++ if (d->bd)
++ BUG();
++
++ if (!(d->bd = bdget(kdev_t_to_nr(d->dev))))
++ return -ENOMEM;
++
++ if ((err = blkdev_get(d->bd, FMODE_READ | FMODE_WRITE, 0, BDEV_FILE)))
++ return err;
++
++ return 0;
++}
++
++/*
++ * Close a device that we've been using.
++ */
++static void close_dev(struct dm_dev *d)
++{
++ if (!d->bd)
++ return;
++
++ blkdev_put(d->bd, BDEV_FILE);
++ d->bd = NULL;
++}
++
++/*
++ * If possible (ie. blk_size[major] is set), this
++ * checks an area of a destination device is
++ * valid.
++ */
++static int check_device_area(kdev_t dev, offset_t start, offset_t len)
++{
++ int *sizes;
++ offset_t dev_size;
++
++ if (!(sizes = blk_size[MAJOR(dev)]) || !(dev_size = sizes[MINOR(dev)]))
++ /* we don't know the device details,
++ * so give the benefit of the doubt */
++ return 1;
++
++ /* convert to 512-byte sectors */
++ dev_size <<= 1;
++
++ return ((start < dev_size) && (len <= (dev_size - start)));
++}
++
++/*
++ * Add a device to the list, or just increment the usage count
++ * if it's already present.
++ */
++int dm_table_get_device(struct dm_table *t, const char *path,
++ offset_t start, offset_t len, struct dm_dev **result)
++{
++ int r;
++ kdev_t dev;
++ struct dm_dev *dd;
++ int major, minor;
++
++ if (sscanf(path, "%x:%x", &major, &minor) == 2) {
++ /* Extract the major/minor numbers */
++ dev = MKDEV(major, minor);
++ } else {
++ /* convert the path to a device */
++ if ((r = lookup_device(path, &dev)))
++ return r;
++ }
++
++ dd = find_device(&t->devices, dev);
++ if (!dd) {
++ dd = kmalloc(sizeof(*dd), GFP_KERNEL);
++ if (!dd)
++ return -ENOMEM;
++
++ dd->dev = dev;
++ dd->bd = NULL;
++
++ if ((r = open_dev(dd))) {
++ kfree(dd);
++ return r;
++ }
++
++ atomic_set(&dd->count, 0);
++ list_add(&dd->list, &t->devices);
++ }
++ atomic_inc(&dd->count);
++
++ if (!check_device_area(dd->dev, start, len)) {
++ DMWARN("device %s too small for target", path);
++ dm_table_put_device(t, dd);
++ return -EINVAL;
++ }
++
++ *result = dd;
++
++ return 0;
++}
++
++/*
++ * Decrement a devices use count and remove it if neccessary.
++ */
++void dm_table_put_device(struct dm_table *t, struct dm_dev *dd)
++{
++ if (atomic_dec_and_test(&dd->count)) {
++ close_dev(dd);
++ list_del(&dd->list);
++ kfree(dd);
++ }
++}
++
++/*
++ * Adds a target to the map
++ */
++int dm_table_add_target(struct dm_table *t, offset_t highs,
++ struct target_type *type, void *private)
++{
++ int r, n;
++
++ if ((r = check_space(t)))
++ return r;
++
++ n = t->num_targets++;
++ t->highs[n] = highs;
++ t->targets[n].type = type;
++ t->targets[n].private = private;
++
++ return 0;
++}
++
++static int setup_indexes(struct dm_table *t)
++{
++ int i, total = 0;
++ offset_t *indexes;
++
++ /* allocate the space for *all* the indexes */
++ for (i = t->depth - 2; i >= 0; i--) {
++ t->counts[i] = div_up(t->counts[i + 1], CHILDREN_PER_NODE);
++ total += t->counts[i];
++ }
++
++ indexes = (offset_t *) vcalloc(total, (unsigned long) NODE_SIZE);
++ if (!indexes)
++ return -ENOMEM;
++
++ /* set up internal nodes, bottom-up */
++ for (i = t->depth - 2, total = 0; i >= 0; i--) {
++ t->index[i] = indexes;
++ indexes += (KEYS_PER_NODE * t->counts[i]);
++ setup_btree_index(i, t);
++ }
++
++ return 0;
++}
++
++/*
++ * Builds the btree to index the map
++ */
++int dm_table_complete(struct dm_table *t)
++{
++ int leaf_nodes, r = 0;
++
++ /* how many indexes will the btree have ? */
++ leaf_nodes = div_up(t->num_targets, KEYS_PER_NODE);
++ t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
++
++ /* leaf layer has already been set up */
++ t->counts[t->depth - 1] = leaf_nodes;
++ t->index[t->depth - 1] = t->highs;
++
++ if (t->depth >= 2)
++ r = setup_indexes(t);
++
++ return r;
++}
++
++void dm_table_event(struct dm_table *t)
++{
++ wake_up_interruptible(&t->eventq);
++}
++
++EXPORT_SYMBOL(dm_table_get_device);
++EXPORT_SYMBOL(dm_table_put_device);
++EXPORT_SYMBOL(dm_table_event);
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-target.c linux/drivers/md/dm-target.c
+--- linux-2.4.19-rc1/drivers/md/dm-target.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-target.c Tue Jun 25 22:02:56 2002
+@@ -0,0 +1,242 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++
++#include <linux/kmod.h>
++
++struct tt_internal {
++ struct target_type tt;
++
++ struct list_head list;
++ long use;
++};
++
++static LIST_HEAD(_targets);
++static rwlock_t _lock = RW_LOCK_UNLOCKED;
++
++#define DM_MOD_NAME_SIZE 32
++
++/*
++ * Destructively splits up the argument list to pass to ctr.
++ */
++int split_args(int max, int *argc, char **argv, char *input)
++{
++ char *start, *end = input, *out;
++ *argc = 0;
++
++ while (1) {
++ start = end;
++
++ /* Skip whitespace */
++ while (*start && isspace(*start))
++ start++;
++
++ if (!*start)
++ break; /* success, we hit the end */
++
++ /* 'out' is used to remove any back-quotes */
++ end = out = start;
++ while (*end) {
++ /* Everything apart from '\0' can be quoted */
++ if (*end == '\\' && *(end + 1)) {
++ *out++ = *(end + 1);
++ end += 2;
++ continue;
++ }
++
++ if (isspace(*end))
++ break; /* end of token */
++
++ *out++ = *end++;
++ }
++
++ /* have we already filled the array ? */
++ if ((*argc + 1) > max)
++ return -EINVAL;
++
++ /* we know this is whitespace */
++ if (*end)
++ end++;
++
++ /* terminate the string and put it in the array */
++ *out = '\0';
++ argv[*argc] = start;
++ (*argc)++;
++ }
++
++ return 0;
++}
++
++static inline struct tt_internal *__find_target_type(const char *name)
++{
++ struct list_head *tih;
++ struct tt_internal *ti;
++
++ list_for_each(tih, &_targets) {
++ ti = list_entry(tih, struct tt_internal, list);
++
++ if (!strcmp(name, ti->tt.name))
++ return ti;
++ }
++
++ return NULL;
++}
++
++static struct tt_internal *get_target_type(const char *name)
++{
++ struct tt_internal *ti;
++
++ read_lock(&_lock);
++ ti = __find_target_type(name);
++
++ if (ti) {
++ if (ti->use == 0 && ti->tt.module)
++ __MOD_INC_USE_COUNT(ti->tt.module);
++ ti->use++;
++ }
++ read_unlock(&_lock);
++
++ return ti;
++}
++
++static void load_module(const char *name)
++{
++ char module_name[DM_MOD_NAME_SIZE] = "dm-";
++
++ /* Length check for strcat() below */
++ if (strlen(name) > (DM_MOD_NAME_SIZE - 4))
++ return;
++
++ strcat(module_name, name);
++ request_module(module_name);
++
++ return;
++}
++
++struct target_type *dm_get_target_type(const char *name)
++{
++ struct tt_internal *ti = get_target_type(name);
++
++ if (!ti) {
++ load_module(name);
++ ti = get_target_type(name);
++ }
++
++ return ti ? &ti->tt : NULL;
++}
++
++void dm_put_target_type(struct target_type *t)
++{
++ struct tt_internal *ti = (struct tt_internal *) t;
++
++ read_lock(&_lock);
++ if (--ti->use == 0 && ti->tt.module)
++ __MOD_DEC_USE_COUNT(ti->tt.module);
++
++ if (ti->use < 0)
++ BUG();
++ read_unlock(&_lock);
++
++ return;
++}
++
++static struct tt_internal *alloc_target(struct target_type *t)
++{
++ struct tt_internal *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
++
++ if (ti) {
++ memset(ti, 0, sizeof(*ti));
++ ti->tt = *t;
++ }
++
++ return ti;
++}
++
++int dm_register_target(struct target_type *t)
++{
++ int rv = 0;
++ struct tt_internal *ti = alloc_target(t);
++
++ if (!ti)
++ return -ENOMEM;
++
++ write_lock(&_lock);
++ if (__find_target_type(t->name))
++ rv = -EEXIST;
++ else
++ list_add(&ti->list, &_targets);
++
++ write_unlock(&_lock);
++ return rv;
++}
++
++int dm_unregister_target(struct target_type *t)
++{
++ struct tt_internal *ti;
++
++ write_lock(&_lock);
++ if (!(ti = __find_target_type(t->name))) {
++ write_unlock(&_lock);
++ return -EINVAL;
++ }
++
++ if (ti->use) {
++ write_unlock(&_lock);
++ return -ETXTBSY;
++ }
++
++ list_del(&ti->list);
++ kfree(ti);
++
++ write_unlock(&_lock);
++ return 0;
++}
++
++/*
++ * io-err: always fails an io, useful for bringing
++ * up LV's that have holes in them.
++ */
++static int io_err_ctr(struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **args, void **context)
++{
++ *context = NULL;
++ return 0;
++}
++
++static void io_err_dtr(struct dm_table *t, void *c)
++{
++ /* empty */
++ return;
++}
++
++static int io_err_map(struct buffer_head *bh, int rw, void *context)
++{
++ buffer_IO_error(bh);
++ return 0;
++}
++
++static struct target_type error_target = {
++ name: "error",
++ ctr: io_err_ctr,
++ dtr: io_err_dtr,
++ map: io_err_map,
++ status: NULL,
++};
++
++int dm_target_init(void)
++{
++ return dm_register_target(&error_target);
++}
++
++void dm_target_exit(void)
++{
++ if (dm_unregister_target(&error_target))
++ DMWARN("error target unregistration failed");
++}
++
++EXPORT_SYMBOL(dm_register_target);
++EXPORT_SYMBOL(dm_unregister_target);
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.c linux/drivers/md/dm.c
+--- linux-2.4.19-rc1/drivers/md/dm.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm.c Tue Jun 25 22:12:09 2002
+@@ -0,0 +1,1168 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++
++#include <linux/blk.h>
++#include <linux/blkpg.h>
++
++/* we only need this for the lv_bmap struct definition, not happy */
++#include <linux/lvm.h>
++
++#define DEFAULT_READ_AHEAD 64
++
++static const char *_name = DM_NAME;
++
++static int major = 0;
++static int _major = 0;
++
++struct io_hook {
++ struct mapped_device *md;
++ struct target *target;
++ int rw;
++
++ void (*end_io) (struct buffer_head * bh, int uptodate);
++ void *context;
++};
++
++static kmem_cache_t *_io_hook_cache;
++
++static struct mapped_device *_devs[MAX_DEVICES];
++static struct rw_semaphore _dev_locks[MAX_DEVICES];
++
++/*
++ * This lock is only held by dm_create and dm_set_name to avoid
++ * race conditions where someone else may create a device with
++ * the same name.
++ */
++static spinlock_t _create_lock = SPIN_LOCK_UNLOCKED;
++
++/* block device arrays */
++static int _block_size[MAX_DEVICES];
++static int _blksize_size[MAX_DEVICES];
++static int _hardsect_size[MAX_DEVICES];
++
++static devfs_handle_t _dev_dir;
++
++static int request(request_queue_t * q, int rw, struct buffer_head *bh);
++static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb);
++
++/*
++ * Protect the mapped_devices referenced from _dev[]
++ */
++struct mapped_device *dm_get_r(int minor)
++{
++ struct mapped_device *md;
++
++ if (minor >= MAX_DEVICES)
++ return NULL;
++
++ down_read(_dev_locks + minor);
++ md = _devs[minor];
++ if (!md)
++ up_read(_dev_locks + minor);
++ return md;
++}
++
++struct mapped_device *dm_get_w(int minor)
++{
++ struct mapped_device *md;
++
++ if (minor >= MAX_DEVICES)
++ return NULL;
++
++ down_write(_dev_locks + minor);
++ md = _devs[minor];
++ if (!md)
++ up_write(_dev_locks + minor);
++ return md;
++}
++
++static int namecmp(struct mapped_device *md, const char *name, int nametype)
++{
++ switch (nametype) {
++ case DM_LOOKUP_BY_NAME:
++ return strcmp(md->name, name);
++ break;
++
++ case DM_LOOKUP_BY_UUID:
++ if (!md->uuid)
++ return -1; /* never equal */
++
++ return strcmp(md->uuid, name);
++ break;
++
++ default:
++ DMWARN("Unknown comparison type in namecmp: %d", nametype);
++ BUG();
++ }
++
++ return -1;
++}
++
++/*
++ * The interface (eg, ioctl) will probably access the devices
++ * through these slow 'by name' locks, this needs improving at
++ * some point if people start playing with *large* numbers of dm
++ * devices.
++ */
++struct mapped_device *dm_get_name_r(const char *name, int nametype)
++{
++ int i;
++ struct mapped_device *md;
++
++ for (i = 0; i < MAX_DEVICES; i++) {
++ md = dm_get_r(i);
++ if (md) {
++ if (!namecmp(md, name, nametype))
++ return md;
++
++ dm_put_r(md);
++ }
++ }
++
++ return NULL;
++}
++
++struct mapped_device *dm_get_name_w(const char *name, int nametype)
++{
++ int i;
++ struct mapped_device *md;
++
++ /*
++ * To avoid getting write locks on all the devices we try
++ * and promote a read lock to a write lock, this can
++ * fail, in which case we just start again.
++ */
++
++ restart:
++ for (i = 0; i < MAX_DEVICES; i++) {
++ md = dm_get_r(i);
++ if (!md)
++ continue;
++
++ if (namecmp(md, name, nametype)) {
++ dm_put_r(md);
++ continue;
++ }
++
++ /* found it */
++ dm_put_r(md);
++
++ md = dm_get_w(i);
++ if (!md)
++ goto restart;
++
++ if (namecmp(md, name, nametype)) {
++ dm_put_w(md);
++ goto restart;
++ }
++
++ return md;
++ }
++
++ return NULL;
++}
++
++void dm_put_r(struct mapped_device *md)
++{
++ int minor = MINOR(md->dev);
++
++ if (minor >= MAX_DEVICES)
++ return;
++
++ up_read(_dev_locks + minor);
++}
++
++void dm_put_w(struct mapped_device *md)
++{
++ int minor = MINOR(md->dev);
++
++ if (minor >= MAX_DEVICES)
++ return;
++
++ up_write(_dev_locks + minor);
++}
++
++/*
++ * Setup and tear down the driver
++ */
++static __init void init_locks(void)
++{
++ int i;
++
++ for (i = 0; i < MAX_DEVICES; i++)
++ init_rwsem(_dev_locks + i);
++}
++
++static __init int local_init(void)
++{
++ int r;
++
++ init_locks();
++
++ /* allocate a slab for the io-hooks */
++ if (!_io_hook_cache &&
++ !(_io_hook_cache = kmem_cache_create("dm io hooks",
++ sizeof(struct io_hook),
++ 0, 0, NULL, NULL)))
++ return -ENOMEM;
++
++ _major = major;
++ r = devfs_register_blkdev(_major, _name, &dm_blk_dops);
++ if (r < 0) {
++ DMERR("register_blkdev failed");
++ kmem_cache_destroy(_io_hook_cache);
++ return r;
++ }
++
++ if (!_major)
++ _major = r;
++
++ /* set up the arrays */
++ read_ahead[_major] = DEFAULT_READ_AHEAD;
++ blk_size[_major] = _block_size;
++ blksize_size[_major] = _blksize_size;
++ hardsect_size[_major] = _hardsect_size;
++
++ blk_queue_make_request(BLK_DEFAULT_QUEUE(_major), request);
++
++ _dev_dir = devfs_mk_dir(0, DM_DIR, NULL);
++
++ return 0;
++}
++
++static void local_exit(void)
++{
++ if (kmem_cache_destroy(_io_hook_cache))
++ DMWARN("io_hooks still allocated during unregistration");
++ _io_hook_cache = NULL;
++
++ if (devfs_unregister_blkdev(_major, _name) < 0)
++ DMERR("devfs_unregister_blkdev failed");
++
++ read_ahead[_major] = 0;
++ blk_size[_major] = NULL;
++ blksize_size[_major] = NULL;
++ hardsect_size[_major] = NULL;
++ _major = 0;
++
++ DMINFO("cleaned up");
++}
++
++/*
++ * We have a lot of init/exit functions, so it seems easier to
++ * store them in an array. The disposable macro 'xx'
++ * expands a prefix into a pair of function names.
++ */
++static struct {
++ int (*init)(void);
++ void (*exit)(void);
++
++} _inits[] = {
++#define xx(n) {n ## _init, n ## _exit},
++ xx(local)
++ xx(dm_target)
++#undef xx
++};
++
++static int __init dm_init(void)
++{
++ const int count = sizeof(_inits) / sizeof(*_inits);
++
++ int r, i;
++
++ for (i = 0; i < count; i++) {
++ r = _inits[i].init();
++ if (r)
++ goto bad;
++ }
++
++ return 0;
++
++ bad:
++ while (i--)
++ _inits[i].exit();
++
++ return r;
++}
++
++static void __exit dm_exit(void)
++{
++ int i = sizeof(_inits) / sizeof(*_inits);
++
++ dm_destroy_all();
++ while (i--)
++ _inits[i].exit();
++}
++
++/*
++ * Block device functions
++ */
++static int dm_blk_open(struct inode *inode, struct file *file)
++{
++ struct mapped_device *md;
++
++ md = dm_get_w(MINOR(inode->i_rdev));
++ if (!md)
++ return -ENXIO;
++
++ md->use_count++;
++ dm_put_w(md);
++
++ return 0;
++}
++
++static int dm_blk_close(struct inode *inode, struct file *file)
++{
++ struct mapped_device *md;
++
++ md = dm_get_w(MINOR(inode->i_rdev));
++ if (!md)
++ return -ENXIO;
++
++ if (md->use_count < 1)
++ DMWARN("incorrect reference count found in mapped_device");
++
++ md->use_count--;
++ dm_put_w(md);
++
++ return 0;
++}
++
++/* In 512-byte units */
++#define VOLUME_SIZE(minor) (_block_size[(minor)] << 1)
++
++static int dm_blk_ioctl(struct inode *inode, struct file *file,
++ uint command, unsigned long a)
++{
++ int minor = MINOR(inode->i_rdev);
++ long size;
++
++ if (minor >= MAX_DEVICES)
++ return -ENXIO;
++
++ switch (command) {
++ case BLKROSET:
++ case BLKROGET:
++ case BLKRASET:
++ case BLKRAGET:
++ case BLKFLSBUF:
++ case BLKSSZGET:
++ //case BLKRRPART: /* Re-read partition tables */
++ //case BLKPG:
++ case BLKELVGET:
++ case BLKELVSET:
++ case BLKBSZGET:
++ case BLKBSZSET:
++ return blk_ioctl(inode->i_rdev, command, a);
++ break;
++
++ case BLKGETSIZE:
++ size = VOLUME_SIZE(minor);
++ if (copy_to_user((void *) a, &size, sizeof(long)))
++ return -EFAULT;
++ break;
++
++ case BLKGETSIZE64:
++ size = VOLUME_SIZE(minor);
++ if (put_user((u64) ((u64) size) << 9, (u64 *) a))
++ return -EFAULT;
++ break;
++
++ case BLKRRPART:
++ return -ENOTTY;
++
++ case LV_BMAP:
++ return dm_user_bmap(inode, (struct lv_bmap *) a);
++
++ default:
++ DMWARN("unknown block ioctl 0x%x", command);
++ return -ENOTTY;
++ }
++
++ return 0;
++}
++
++static inline struct io_hook *alloc_io_hook(void)
++{
++ return kmem_cache_alloc(_io_hook_cache, GFP_NOIO);
++}
++
++static inline void free_io_hook(struct io_hook *ih)
++{
++ kmem_cache_free(_io_hook_cache, ih);
++}
++
++/*
++ * FIXME: We need to decide if deferred_io's need
++ * their own slab, I say no for now since they are
++ * only used when the device is suspended.
++ */
++static inline struct deferred_io *alloc_deferred(void)
++{
++ return kmalloc(sizeof(struct deferred_io), GFP_NOIO);
++}
++
++static inline void free_deferred(struct deferred_io *di)
++{
++ kfree(di);
++}
++
++/*
++ * Call a target's optional error function if an I/O failed.
++ */
++static inline int call_err_fn(struct io_hook *ih, struct buffer_head *bh)
++{
++ dm_err_fn err = ih->target->type->err;
++
++ if (err)
++ return err(bh, ih->rw, ih->target->private);
++
++ return 0;
++}
++
++/*
++ * bh->b_end_io routine that decrements the pending count
++ * and then calls the original bh->b_end_io fn.
++ */
++static void dec_pending(struct buffer_head *bh, int uptodate)
++{
++ struct io_hook *ih = bh->b_bdev_private;
++
++ if (!uptodate && call_err_fn(ih, bh))
++ return;
++
++ if (atomic_dec_and_test(&ih->md->pending))
++ /* nudge anyone waiting on suspend queue */
++ wake_up(&ih->md->wait);
++
++ bh->b_end_io = ih->end_io;
++ bh->b_bdev_private = ih->context;
++ free_io_hook(ih);
++
++ bh->b_end_io(bh, uptodate);
++}
++
++/*
++ * Add the bh to the list of deferred io.
++ */
++static int queue_io(struct buffer_head *bh, int rw)
++{
++ struct deferred_io *di = alloc_deferred();
++ struct mapped_device *md;
++
++ if (!di)
++ return -ENOMEM;
++
++ md = dm_get_w(MINOR(bh->b_rdev));
++ if (!md) {
++ free_deferred(di);
++ return -ENXIO;
++ }
++
++ if (!md->suspended) {
++ dm_put_w(md);
++ free_deferred(di);
++ return 1;
++ }
++
++ di->bh = bh;
++ di->rw = rw;
++ di->next = md->deferred;
++ md->deferred = di;
++
++ dm_put_w(md);
++
++ return 0; /* deferred successfully */
++}
++
++/*
++ * Do the bh mapping for a given leaf
++ */
++static inline int __map_buffer(struct mapped_device *md,
++ struct buffer_head *bh, int rw, int leaf)
++{
++ int r;
++ dm_map_fn fn;
++ void *context;
++ struct io_hook *ih = NULL;
++ struct target *ti = md->map->targets + leaf;
++
++ fn = ti->type->map;
++ context = ti->private;
++
++ ih = alloc_io_hook();
++
++ if (!ih)
++ return -1;
++
++ ih->md = md;
++ ih->rw = rw;
++ ih->target = ti;
++ ih->end_io = bh->b_end_io;
++ ih->context = bh->b_bdev_private;
++
++ r = fn(bh, rw, context);
++
++ if (r > 0) {
++ /* hook the end io request fn */
++ atomic_inc(&md->pending);
++ bh->b_end_io = dec_pending;
++ bh->b_bdev_private = ih;
++
++ } else if (r == 0)
++ /* we don't need to hook */
++ free_io_hook(ih);
++
++ else if (r < 0) {
++ free_io_hook(ih);
++ return -1;
++ }
++
++ return r;
++}
++
++/*
++ * Search the btree for the correct target.
++ */
++static inline int __find_node(struct dm_table *t, struct buffer_head *bh)
++{
++ int l, n = 0, k = 0;
++ offset_t *node;
++
++ for (l = 0; l < t->depth; l++) {
++ n = get_child(n, k);
++ node = get_node(t, l, n);
++
++ for (k = 0; k < KEYS_PER_NODE; k++)
++ if (node[k] >= bh->b_rsector)
++ break;
++ }
++
++ return (KEYS_PER_NODE * n) + k;
++}
++
++static int request(request_queue_t * q, int rw, struct buffer_head *bh)
++{
++ struct mapped_device *md;
++ int r, minor = MINOR(bh->b_rdev);
++ unsigned int block_size = _blksize_size[minor];
++
++ md = dm_get_r(minor);
++ if (!md) {
++ buffer_IO_error(bh);
++ return 0;
++ }
++
++ /*
++ * Sanity checks.
++ */
++ if (bh->b_size > block_size)
++ DMERR("request is larger than block size "
++ "b_size (%d), block size (%d)",
++ bh->b_size, block_size);
++
++ if (bh->b_rsector & ((bh->b_size >> 9) - 1))
++ DMERR("misaligned block requested logical "
++ "sector (%lu), b_size (%d)",
++ bh->b_rsector, bh->b_size);
++
++ /*
++ * If we're suspended we have to queue
++ * this io for later.
++ */
++ while (md->suspended) {
++ dm_put_r(md);
++
++ if (rw == READA)
++ goto bad_no_lock;
++
++ r = queue_io(bh, rw);
++
++ if (r < 0)
++ goto bad_no_lock;
++
++ else if (r == 0)
++ return 0; /* deferred successfully */
++
++ /*
++ * We're in a while loop, because someone could suspend
++ * before we get to the following read lock.
++ */
++ md = dm_get_r(minor);
++ if (!md) {
++ buffer_IO_error(bh);
++ return 0;
++ }
++ }
++
++ if ((r = __map_buffer(md, bh, rw, __find_node(md->map, bh))) < 0)
++ goto bad;
++
++ dm_put_r(md);
++ return r;
++
++ bad:
++ dm_put_r(md);
++
++ bad_no_lock:
++ buffer_IO_error(bh);
++ return 0;
++}
++
++static int check_dev_size(int minor, unsigned long block)
++{
++ /* FIXME: check this */
++ unsigned long max_sector = (_block_size[minor] << 1) + 1;
++ unsigned long sector = (block + 1) * (_blksize_size[minor] >> 9);
++
++ return (sector > max_sector) ? 0 : 1;
++}
++
++/*
++ * Creates a dummy buffer head and maps it (for lilo).
++ */
++static int do_bmap(kdev_t dev, unsigned long block,
++ kdev_t * r_dev, unsigned long *r_block)
++{
++ struct mapped_device *md;
++ struct buffer_head bh;
++ int minor = MINOR(dev), r;
++ struct target *t;
++
++ md = dm_get_r(minor);
++ if (!md)
++ return -ENXIO;
++
++ if (md->suspended) {
++ dm_put_r(md);
++ return -EPERM;
++ }
++
++ if (!check_dev_size(minor, block)) {
++ dm_put_r(md);
++ return -EINVAL;
++ }
++
++ /* setup dummy bh */
++ memset(&bh, 0, sizeof(bh));
++ bh.b_blocknr = block;
++ bh.b_dev = bh.b_rdev = dev;
++ bh.b_size = _blksize_size[minor];
++ bh.b_rsector = block * (bh.b_size >> 9);
++
++ /* find target */
++ t = md->map->targets + __find_node(md->map, &bh);
++
++ /* do the mapping */
++ r = t->type->map(&bh, READ, t->private);
++
++ *r_dev = bh.b_rdev;
++ *r_block = bh.b_rsector / (bh.b_size >> 9);
++
++ dm_put_r(md);
++ return r;
++}
++
++/*
++ * Marshals arguments and results between user and kernel space.
++ */
++static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb)
++{
++ unsigned long block, r_block;
++ kdev_t r_dev;
++ int r;
++
++ if (get_user(block, &lvb->lv_block))
++ return -EFAULT;
++
++ if ((r = do_bmap(inode->i_rdev, block, &r_dev, &r_block)))
++ return r;
++
++ if (put_user(kdev_t_to_nr(r_dev), &lvb->lv_dev) ||
++ put_user(r_block, &lvb->lv_block))
++ return -EFAULT;
++
++ return 0;
++}
++
++/*
++ * See if the device with a specific minor # is free. The write
++ * lock is held when it returns successfully.
++ */
++static inline int specific_dev(int minor, struct mapped_device *md)
++{
++ if (minor >= MAX_DEVICES) {
++ DMWARN("request for a mapped_device beyond MAX_DEVICES (%d)",
++ MAX_DEVICES);
++ return -1;
++ }
++
++ down_write(_dev_locks + minor);
++ if (_devs[minor]) {
++ /* in use */
++ up_write(_dev_locks + minor);
++ return -1;
++ }
++
++ return minor;
++}
++
++/*
++ * Find the first free device. Again the write lock is held on
++ * success.
++ */
++static int any_old_dev(struct mapped_device *md)
++{
++ int i;
++
++ for (i = 0; i < MAX_DEVICES; i++)
++ if (specific_dev(i, md) != -1)
++ return i;
++
++ return -1;
++}
++
++/*
++ * Allocate and initialise a blank device.
++ * Caller must ensure uuid is null-terminated.
++ * Device is returned with a write lock held.
++ */
++static struct mapped_device *alloc_dev(const char *name, const char *uuid,
++ int minor)
++{
++ struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL);
++ int len;
++
++ if (!md) {
++ DMWARN("unable to allocate device, out of memory.");
++ return NULL;
++ }
++
++ memset(md, 0, sizeof(*md));
++
++ /*
++ * This grabs the write lock if it succeeds.
++ */
++ minor = (minor < 0) ? any_old_dev(md) : specific_dev(minor, md);
++ if (minor < 0) {
++ kfree(md);
++ return NULL;
++ }
++
++ md->dev = MKDEV(_major, minor);
++ md->suspended = 0;
++
++ strncpy(md->name, name, sizeof(md->name) - 1);
++ md->name[sizeof(md->name) - 1] = '\0';
++
++ /*
++ * Copy in the uuid.
++ */
++ if (uuid && *uuid) {
++ len = strlen(uuid) + 1;
++ if (!(md->uuid = kmalloc(len, GFP_KERNEL))) {
++ DMWARN("unable to allocate uuid - out of memory.");
++ kfree(md);
++ return NULL;
++ }
++ strcpy(md->uuid, uuid);
++ }
++
++ init_waitqueue_head(&md->wait);
++ return md;
++}
++
++static int __register_device(struct mapped_device *md)
++{
++ md->devfs_entry =
++ devfs_register(_dev_dir, md->name, DEVFS_FL_CURRENT_OWNER,
++ MAJOR(md->dev), MINOR(md->dev),
++ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
++ &dm_blk_dops, NULL);
++
++ return 0;
++}
++
++static int __unregister_device(struct mapped_device *md)
++{
++ devfs_unregister(md->devfs_entry);
++ return 0;
++}
++
++/*
++ * The hardsect size for a mapped device is the smallest hardsect size
++ * from the devices it maps onto.
++ */
++static int __find_hardsect_size(struct list_head *devices)
++{
++ int result = INT_MAX, size;
++ struct list_head *tmp;
++
++ list_for_each(tmp, devices) {
++ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
++ size = get_hardsect_size(dd->dev);
++ if (size < result)
++ result = size;
++ }
++
++ /*
++ * I think it's safe to assume that no block devices have
++ * a hard sector size this large.
++ */
++ if (result == INT_MAX)
++ result = 512;
++
++ return result;
++}
++
++/*
++ * Bind a table to the device.
++ */
++static int __bind(struct mapped_device *md, struct dm_table *t)
++{
++ int minor = MINOR(md->dev);
++
++ md->map = t;
++
++ if (!t->num_targets) {
++ _block_size[minor] = 0;
++ _blksize_size[minor] = BLOCK_SIZE;
++ _hardsect_size[minor] = 0;
++ return 0;
++ }
++
++ /* in k */
++ _block_size[minor] = (t->highs[t->num_targets - 1] + 1) >> 1;
++
++ _blksize_size[minor] = BLOCK_SIZE;
++ _hardsect_size[minor] = __find_hardsect_size(&t->devices);
++ register_disk(NULL, md->dev, 1, &dm_blk_dops, _block_size[minor]);
++
++ return 0;
++}
++
++static void __unbind(struct mapped_device *md)
++{
++ int minor = MINOR(md->dev);
++
++ dm_table_destroy(md->map);
++ md->map = NULL;
++
++ _block_size[minor] = 0;
++ _blksize_size[minor] = 0;
++ _hardsect_size[minor] = 0;
++}
++
++static int check_name(const char *name)
++{
++ struct mapped_device *md;
++
++ if (strchr(name, '/') || strlen(name) > DM_NAME_LEN) {
++ DMWARN("invalid device name");
++ return -1;
++ }
++
++ md = dm_get_name_r(name, DM_LOOKUP_BY_NAME);
++ if (md) {
++ dm_put_r(md);
++ DMWARN("device name already in use");
++ return -1;
++ }
++
++ return 0;
++}
++
++static int check_uuid(const char *uuid)
++{
++ struct mapped_device *md;
++
++ if (uuid) {
++ md = dm_get_name_r(uuid, DM_LOOKUP_BY_UUID);
++ if (md) {
++ dm_put_r(md);
++ DMWARN("device uuid already in use");
++ return -1;
++ }
++ }
++
++ return 0;
++}
++
++/*
++ * Constructor for a new device.
++ */
++int dm_create(const char *name, const char *uuid, int minor, int ro,
++ struct dm_table *table)
++{
++ int r;
++ struct mapped_device *md;
++
++ spin_lock(&_create_lock);
++ if (check_name(name) || check_uuid(uuid)) {
++ spin_unlock(&_create_lock);
++ return -EINVAL;
++ }
++
++ md = alloc_dev(name, uuid, minor);
++ if (!md) {
++ spin_unlock(&_create_lock);
++ return -ENXIO;
++ }
++ minor = MINOR(md->dev);
++ _devs[minor] = md;
++
++ r = __register_device(md);
++ if (r)
++ goto err;
++
++ r = __bind(md, table);
++ if (r)
++ goto err;
++
++ dm_set_ro(md, ro);
++
++ spin_unlock(&_create_lock);
++ dm_put_w(md);
++ return 0;
++
++ err:
++ _devs[minor] = NULL;
++ if (md->uuid)
++ kfree(md->uuid);
++
++ dm_put_w(md);
++ kfree(md);
++ spin_unlock(&_create_lock);
++ return r;
++}
++
++/*
++ * Renames the device. No lock held.
++ */
++int dm_set_name(const char *name, int nametype, const char *newname)
++{
++ int r;
++ struct mapped_device *md;
++
++ spin_lock(&_create_lock);
++ if (check_name(newname) < 0) {
++ spin_unlock(&_create_lock);
++ return -EINVAL;
++ }
++
++ md = dm_get_name_w(name, nametype);
++ if (!md) {
++ spin_unlock(&_create_lock);
++ return -ENXIO;
++ }
++
++ r = __unregister_device(md);
++ if (r)
++ goto out;
++
++ strcpy(md->name, newname);
++ r = __register_device(md);
++
++ out:
++ dm_put_w(md);
++ spin_unlock(&_create_lock);
++ return r;
++}
++
++/*
++ * Destructor for the device. You cannot destroy an open
++ * device. Write lock must be held before calling.
++ * Caller must dm_put_w(md) then kfree(md) if call was successful.
++ */
++int dm_destroy(struct mapped_device *md)
++{
++ int minor, r;
++
++ if (md->use_count)
++ return -EPERM;
++
++ r = __unregister_device(md);
++ if (r)
++ return r;
++
++ minor = MINOR(md->dev);
++ _devs[minor] = NULL;
++ __unbind(md);
++
++ if (md->uuid)
++ kfree(md->uuid);
++
++ return 0;
++}
++
++/*
++ * Destroy all devices - except open ones
++ */
++void dm_destroy_all(void)
++{
++ int i, some_destroyed, r;
++ struct mapped_device *md;
++
++ do {
++ some_destroyed = 0;
++ for (i = 0; i < MAX_DEVICES; i++) {
++ md = dm_get_w(i);
++ if (!md)
++ continue;
++
++ r = dm_destroy(md);
++ dm_put_w(md);
++
++ if (!r) {
++ kfree(md);
++ some_destroyed = 1;
++ }
++ }
++ } while (some_destroyed);
++}
++
++/*
++ * Sets or clears the read-only flag for the device. Write lock
++ * must be held.
++ */
++void dm_set_ro(struct mapped_device *md, int ro)
++{
++ md->read_only = ro;
++ set_device_ro(md->dev, ro);
++}
++
++/*
++ * A target is notifying us of some event
++ */
++void dm_notify(void *target)
++{
++}
++
++/*
++ * Requeue the deferred buffer_heads by calling generic_make_request.
++ */
++static void flush_deferred_io(struct deferred_io *c)
++{
++ struct deferred_io *n;
++
++ while (c) {
++ n = c->next;
++ generic_make_request(c->rw, c->bh);
++ free_deferred(c);
++ c = n;
++ }
++}
++
++/*
++ * Swap in a new table (destroying old one). Write lock must be
++ * held.
++ */
++int dm_swap_table(struct mapped_device *md, struct dm_table *table)
++{
++ int r;
++
++ /* device must be suspended */
++ if (!md->suspended)
++ return -EPERM;
++
++ __unbind(md);
++
++ r = __bind(md, table);
++ if (r)
++ return r;
++
++ return 0;
++}
++
++/*
++ * We need to be able to change a mapping table under a mounted
++ * filesystem. for example we might want to move some data in
++ * the background. Before the table can be swapped with
++ * dm_bind_table, dm_suspend must be called to flush any in
++ * flight buffer_heads and ensure that any further io gets
++ * deferred. Write lock must be held.
++ */
++int dm_suspend(struct mapped_device *md)
++{
++ int minor = MINOR(md->dev);
++ DECLARE_WAITQUEUE(wait, current);
++
++ if (md->suspended)
++ return -EINVAL;
++
++ md->suspended = 1;
++ dm_put_w(md);
++
++ /* wait for all the pending io to flush */
++ add_wait_queue(&md->wait, &wait);
++ current->state = TASK_UNINTERRUPTIBLE;
++ do {
++ md = dm_get_w(minor);
++ if (!md) {
++ /* Caller expects to free this lock. Yuck. */
++ down_write(_dev_locks + minor);
++ return -ENXIO;
++ }
++
++ if (!atomic_read(&md->pending))
++ break;
++
++ dm_put_w(md);
++ schedule();
++
++ } while (1);
++
++ current->state = TASK_RUNNING;
++ remove_wait_queue(&md->wait, &wait);
++
++ return 0;
++}
++
++int dm_resume(struct mapped_device *md)
++{
++ int minor = MINOR(md->dev);
++ struct deferred_io *def;
++
++ if (!md->suspended || !md->map->num_targets)
++ return -EINVAL;
++
++ md->suspended = 0;
++ def = md->deferred;
++ md->deferred = NULL;
++
++ dm_put_w(md);
++ flush_deferred_io(def);
++ run_task_queue(&tq_disk);
++
++ if (!dm_get_w(minor)) {
++ /* FIXME: yuck */
++ down_write(_dev_locks + minor);
++ return -ENXIO;
++ }
++
++ return 0;
++}
++
++struct block_device_operations dm_blk_dops = {
++ open: dm_blk_open,
++ release: dm_blk_close,
++ ioctl: dm_blk_ioctl,
++ owner: THIS_MODULE
++};
++
++/*
++ * module hooks
++ */
++module_init(dm_init);
++module_exit(dm_exit);
++
++MODULE_PARM(major, "i");
++MODULE_PARM_DESC(major, "The major number of the device mapper");
++MODULE_DESCRIPTION(DM_NAME " driver");
++MODULE_AUTHOR("Joe Thornber <thornber@sistina.com>");
++MODULE_LICENSE("GPL");
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.h linux/drivers/md/dm.h
+--- linux-2.4.19-rc1/drivers/md/dm.h Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm.h Tue Jun 25 22:11:46 2002
+@@ -0,0 +1,208 @@
++/*
++ * Internal header file for device mapper
++ *
++ * Copyright (C) 2001 Sistina Software
++ *
++ * This file is released under the LGPL.
++ */
++
++#ifndef DM_INTERNAL_H
++#define DM_INTERNAL_H
++
++#include <linux/config.h>
++#include <linux/version.h>
++#include <linux/major.h>
++#include <linux/iobuf.h>
++#include <linux/module.h>
++#include <linux/fs.h>
++#include <linux/slab.h>
++#include <linux/vmalloc.h>
++#include <linux/compatmac.h>
++#include <linux/cache.h>
++#include <linux/devfs_fs_kernel.h>
++#include <linux/ctype.h>
++#include <linux/device-mapper.h>
++#include <linux/list.h>
++#include <linux/init.h>
++
++#define DM_NAME "device-mapper" /* Name for messaging */
++#define DM_DRIVER_EMAIL "lvm-devel@lists.sistina.com"
++#define MAX_DEPTH 16
++#define NODE_SIZE L1_CACHE_BYTES
++#define KEYS_PER_NODE (NODE_SIZE / sizeof(offset_t))
++#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
++#define MAX_ARGS 32
++#define MAX_DEVICES 256
++
++/*
++ * List of devices that a metadevice uses and should open/close.
++ */
++struct dm_dev {
++ atomic_t count;
++ struct list_head list;
++
++ kdev_t dev;
++ struct block_device *bd;
++};
++
++/*
++ * I/O that had to be deferred while we were suspended
++ */
++struct deferred_io {
++ int rw;
++ struct buffer_head *bh;
++ struct deferred_io *next;
++};
++
++/*
++ * Btree leaf - this does the actual mapping
++ */
++struct target {
++ struct target_type *type;
++ void *private;
++};
++
++/*
++ * The btree
++ */
++struct dm_table {
++ /* btree table */
++ int depth;
++ int counts[MAX_DEPTH]; /* in nodes */
++ offset_t *index[MAX_DEPTH];
++
++ int num_targets;
++ int num_allocated;
++ offset_t *highs;
++ struct target *targets;
++
++ /* a list of devices used by this table */
++ struct list_head devices;
++
++ /*
++ * A waitqueue for processes waiting for something
++ * interesting to happen to this table.
++ */
++ wait_queue_head_t eventq;
++};
++
++/*
++ * The actual device struct
++ */
++struct mapped_device {
++ kdev_t dev;
++ char name[DM_NAME_LEN];
++ char *uuid;
++
++ int use_count;
++ int suspended;
++ int read_only;
++
++ /* a list of io's that arrived while we were suspended */
++ atomic_t pending;
++ wait_queue_head_t wait;
++ struct deferred_io *deferred;
++
++ struct dm_table *map;
++
++ /* used by dm-fs.c */
++ devfs_handle_t devfs_entry;
++};
++
++extern struct block_device_operations dm_blk_dops;
++
++/* dm-target.c */
++int dm_target_init(void);
++struct target_type *dm_get_target_type(const char *name);
++void dm_put_target_type(struct target_type *t);
++void dm_target_exit(void);
++
++/*
++ * Destructively splits argument list to pass to ctr.
++ */
++int split_args(int max, int *argc, char **argv, char *input);
++
++/* dm.c */
++struct mapped_device *dm_get_r(int minor);
++struct mapped_device *dm_get_w(int minor);
++
++/*
++ * There are two ways to lookup a device.
++ */
++enum {
++ DM_LOOKUP_BY_NAME,
++ DM_LOOKUP_BY_UUID
++};
++
++struct mapped_device *dm_get_name_r(const char *name, int nametype);
++struct mapped_device *dm_get_name_w(const char *name, int nametype);
++
++void dm_put_r(struct mapped_device *md);
++void dm_put_w(struct mapped_device *md);
++
++/*
++ * Call with no lock.
++ */
++int dm_create(const char *name, const char *uuid, int minor, int ro,
++ struct dm_table *table);
++int dm_set_name(const char *name, int nametype, const char *newname);
++void dm_destroy_all(void);
++
++/*
++ * You must have the write lock before calling the remaining md
++ * methods.
++ */
++int dm_destroy(struct mapped_device *md);
++void dm_set_ro(struct mapped_device *md, int ro);
++
++/*
++ * The device must be suspended before calling this method.
++ */
++int dm_swap_table(struct mapped_device *md, struct dm_table *t);
++
++/*
++ * A device can still be used while suspended, but I/O is deferred.
++ */
++int dm_suspend(struct mapped_device *md);
++int dm_resume(struct mapped_device *md);
++
++/* dm-table.c */
++int dm_table_create(struct dm_table **result);
++void dm_table_destroy(struct dm_table *t);
++
++int dm_table_add_target(struct dm_table *t, offset_t highs,
++ struct target_type *type, void *private);
++int dm_table_complete(struct dm_table *t);
++
++/*
++ * Event handling
++ */
++void dm_table_event(struct dm_table *t);
++
++#define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
++#define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x)
++#define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x)
++
++/*
++ * Calculate the index of the child node of the n'th node k'th key.
++ */
++static inline int get_child(int n, int k)
++{
++ return (n * CHILDREN_PER_NODE) + k;
++}
++
++/*
++ * Return the n'th node of level l from table t.
++ */
++static inline offset_t *get_node(struct dm_table *t, int l, int n)
++{
++ return t->index[l] + (n * KEYS_PER_NODE);
++}
++
++static inline int array_too_big(unsigned long fixed, unsigned long obj,
++ unsigned long num)
++{
++ return (num > (ULONG_MAX - fixed) / obj);
++}
++
++#endif
+diff -ruN linux-2.4.19-rc1/include/linux/device-mapper.h linux/include/linux/device-mapper.h
+--- linux-2.4.19-rc1/include/linux/device-mapper.h Thu Jan 1 01:00:00 1970
++++ linux/include/linux/device-mapper.h Tue Jun 25 22:02:56 2002
+@@ -0,0 +1,62 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the LGPL.
++ */
++
++#ifndef _LINUX_DEVICE_MAPPER_H
++#define _LINUX_DEVICE_MAPPER_H
++
++#define DM_DIR "device-mapper" /* Slashes not supported */
++#define DM_MAX_TYPE_NAME 16
++#define DM_NAME_LEN 128
++#define DM_UUID_LEN 129
++
++#ifdef __KERNEL__
++
++struct dm_table;
++struct dm_dev;
++typedef unsigned long offset_t;
++
++typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
++
++/*
++ * Prototypes for functions for a target
++ */
++typedef int (*dm_ctr_fn) (struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **argv, void **context);
++typedef void (*dm_dtr_fn) (struct dm_table *t, void *c);
++typedef int (*dm_map_fn) (struct buffer_head *bh, int rw, void *context);
++typedef int (*dm_err_fn) (struct buffer_head *bh, int rw, void *context);
++typedef int (*dm_status_fn) (status_type_t status_type, char *result,
++ int maxlen, void *context);
++
++void dm_error(const char *message);
++
++/*
++ * Constructors should call these functions to ensure destination devices
++ * are opened/closed correctly
++ */
++int dm_table_get_device(struct dm_table *t, const char *path,
++ offset_t start, offset_t len, struct dm_dev **result);
++void dm_table_put_device(struct dm_table *table, struct dm_dev *d);
++
++/*
++ * Information about a target type
++ */
++struct target_type {
++ const char *name;
++ struct module *module;
++ dm_ctr_fn ctr;
++ dm_dtr_fn dtr;
++ dm_map_fn map;
++ dm_err_fn err;
++ dm_status_fn status;
++};
++
++int dm_register_target(struct target_type *t);
++int dm_unregister_target(struct target_type *t);
++
++#endif /* __KERNEL__ */
++
++#endif /* _LINUX_DEVICE_MAPPER_H */
--- /dev/null
+diff -ruN linux-2.4.19-rc1/drivers/md/Makefile linux/drivers/md/Makefile
+--- linux-2.4.19-rc1/drivers/md/Makefile Tue Jun 25 22:18:02 2002
++++ linux/drivers/md/Makefile Tue Jun 25 22:18:35 2002
+@@ -7,7 +7,7 @@
+ export-objs := md.o xor.o dm-table.o dm-target.o
+ list-multi := lvm-mod.o
+ lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
+-dm-mod-objs := dm.o dm-table.o dm-target.o
++dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o
+
+ # Note: link order is important. All raid personalities
+ # and xor.o must come before md.o, as they each initialise
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-ioctl.c linux/drivers/md/dm-ioctl.c
+--- linux-2.4.19-rc1/drivers/md/dm-ioctl.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-ioctl.c Tue Jun 25 22:18:23 2002
+@@ -0,0 +1,807 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++
++#include <linux/miscdevice.h>
++#include <linux/dm-ioctl.h>
++#include <linux/init.h>
++#include <linux/wait.h>
++
++/*-----------------------------------------------------------------
++ * Implementation of the ioctl commands
++ *---------------------------------------------------------------*/
++
++/*
++ * All the ioctl commands get dispatched to functions with this
++ * prototype.
++ */
++typedef int (*ioctl_fn)(struct dm_ioctl *param, struct dm_ioctl *user);
++
++/*
++ * This is really a debug only call.
++ */
++static int remove_all(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ dm_destroy_all();
++ return 0;
++}
++
++/*
++ * Check a string doesn't overrun the chunk of
++ * memory we copied from userland.
++ */
++static int valid_str(char *str, void *begin, void *end)
++{
++ while (((void *) str >= begin) && ((void *) str < end))
++ if (!*str++)
++ return 0;
++
++ return -EINVAL;
++}
++
++static int next_target(struct dm_target_spec *last, uint32_t next,
++ void *begin, void *end,
++ struct dm_target_spec **spec, char **params)
++{
++ *spec = (struct dm_target_spec *)
++ ((unsigned char *) last + next);
++ *params = (char *) (*spec + 1);
++
++ if (*spec < (last + 1) || ((void *) *spec > end))
++ return -EINVAL;
++
++ return valid_str(*params, begin, end);
++}
++
++/*
++ * Checks to see if there's a gap in the table.
++ * Returns true iff there is a gap.
++ */
++static int gap(struct dm_table *table, struct dm_target_spec *spec)
++{
++ if (!table->num_targets)
++ return (spec->sector_start > 0) ? 1 : 0;
++
++ if (spec->sector_start != table->highs[table->num_targets - 1] + 1)
++ return 1;
++
++ return 0;
++}
++
++static int populate_table(struct dm_table *table, struct dm_ioctl *args)
++{
++ int i = 0, r, first = 1, argc;
++ struct dm_target_spec *spec;
++ char *params, *argv[MAX_ARGS];
++ struct target_type *ttype;
++ void *context, *begin, *end;
++ offset_t highs = 0;
++
++ if (!args->target_count) {
++ DMWARN("populate_table: no targets specified");
++ return -EINVAL;
++ }
++
++ begin = (void *) args;
++ end = begin + args->data_size;
++
++#define PARSE_ERROR(msg) {DMWARN(msg); return -EINVAL;}
++
++ for (i = 0; i < args->target_count; i++) {
++
++ if (first)
++ r = next_target((struct dm_target_spec *) args,
++ args->data_start,
++ begin, end, &spec, ¶ms);
++ else
++ r = next_target(spec, spec->next, begin, end,
++ &spec, ¶ms);
++
++ if (r)
++ PARSE_ERROR("unable to find target");
++
++ /* Look up the target type */
++ ttype = dm_get_target_type(spec->target_type);
++ if (!ttype)
++ PARSE_ERROR("unable to find target type");
++
++ if (gap(table, spec))
++ PARSE_ERROR("gap in target ranges");
++
++ /* Split up the parameter list */
++ if (split_args(MAX_ARGS, &argc, argv, params) < 0)
++ PARSE_ERROR("Too many arguments");
++
++ /* Build the target */
++ if (ttype->ctr(table, spec->sector_start, spec->length,
++ argc, argv, &context)) {
++ DMWARN("%s: target constructor failed",
++ (char *) context);
++ return -EINVAL;
++ }
++
++ /* Add the target to the table */
++ highs = spec->sector_start + (spec->length - 1);
++ if (dm_table_add_target(table, highs, ttype, context))
++ PARSE_ERROR("internal error adding target to table");
++
++ first = 0;
++ }
++
++#undef PARSE_ERROR
++
++ r = dm_table_complete(table);
++ return r;
++}
++
++/*
++ * Round up the ptr to the next 'align' boundary. Obviously
++ * 'align' must be a power of 2.
++ */
++static inline void *align_ptr(void *ptr, unsigned int align)
++{
++ align--;
++ return (void *) (((unsigned long) (ptr + align)) & ~align);
++}
++
++/*
++ * Copies a dm_ioctl and an optional additional payload to
++ * userland.
++ */
++static int results_to_user(struct dm_ioctl *user, struct dm_ioctl *param,
++ void *data, uint32_t len)
++{
++ int r;
++ void *ptr = NULL;
++
++ if (data) {
++ ptr = align_ptr(user + 1, sizeof(unsigned long));
++ param->data_start = ptr - (void *) user;
++ }
++
++ /*
++ * The version number has already been filled in, so we
++ * just copy later fields.
++ */
++ r = copy_to_user(&user->data_size, ¶m->data_size,
++ sizeof(*param) - sizeof(param->version));
++ if (r)
++ return -EFAULT;
++
++ if (data) {
++ if (param->data_start + len > param->data_size)
++ return -ENOSPC;
++
++ if (copy_to_user(ptr, data, len))
++ r = -EFAULT;
++ }
++
++ return r;
++}
++
++/*
++ * Fills in a dm_ioctl structure, ready for sending back to
++ * userland.
++ */
++static void __info(struct mapped_device *md, struct dm_ioctl *param)
++{
++ param->flags = DM_EXISTS_FLAG;
++ if (md->suspended)
++ param->flags |= DM_SUSPEND_FLAG;
++ if (md->read_only)
++ param->flags |= DM_READONLY_FLAG;
++
++ strncpy(param->name, md->name, sizeof(param->name));
++
++ if (md->uuid)
++ strncpy(param->uuid, md->uuid, sizeof(param->uuid) - 1);
++ else
++ param->uuid[0] = '\0';
++
++ param->open_count = md->use_count;
++ param->dev = kdev_t_to_nr(md->dev);
++ param->target_count = md->map->num_targets;
++}
++
++/*
++ * Always use UUID for lookups if it's present, otherwise use name.
++ */
++static inline char *lookup_name(struct dm_ioctl *param)
++{
++ return (*param->uuid) ? param->uuid : param->name;
++}
++
++static inline int lookup_type(struct dm_ioctl *param)
++{
++ return (*param->uuid) ? DM_LOOKUP_BY_UUID : DM_LOOKUP_BY_NAME;
++}
++
++#define ALIGNMENT sizeof(int)
++static void *_align(void *ptr, unsigned int a)
++{
++ register unsigned long align = --a;
++
++ return (void *) (((unsigned long) ptr + align) & ~align);
++}
++
++/*
++ * Copies device info back to user space, used by
++ * the create and info ioctls.
++ */
++static int info(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ struct mapped_device *md;
++
++ param->flags = 0;
++
++ md = dm_get_name_r(lookup_name(param), lookup_type(param));
++ if (!md)
++ /*
++ * Device not found - returns cleared exists flag.
++ */
++ goto out;
++
++ __info(md, param);
++ dm_put_r(md);
++
++ out:
++ return results_to_user(user, param, NULL, 0);
++}
++
++static int create(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ int r, ro;
++ struct dm_table *t;
++ int minor;
++
++ r = dm_table_create(&t);
++ if (r)
++ return r;
++
++ r = populate_table(t, param);
++ if (r) {
++ dm_table_destroy(t);
++ return r;
++ }
++
++ minor = (param->flags & DM_PERSISTENT_DEV_FLAG) ?
++ MINOR(to_kdev_t(param->dev)) : -1;
++
++ ro = (param->flags & DM_READONLY_FLAG) ? 1 : 0;
++
++ r = dm_create(param->name, param->uuid, minor, ro, t);
++ if (r) {
++ dm_table_destroy(t);
++ return r;
++ }
++
++ r = info(param, user);
++ return r;
++}
++
++
++
++/*
++ * Build up the status struct for each target
++ */
++static int __status(struct mapped_device *md, struct dm_ioctl *param,
++ char *outbuf, int *len)
++{
++ int i;
++ struct dm_target_spec *spec;
++ uint64_t sector = 0LL;
++ char *outptr;
++ status_type_t type;
++
++ if (param->flags & DM_STATUS_TABLE_FLAG)
++ type = STATUSTYPE_TABLE;
++ else
++ type = STATUSTYPE_INFO;
++
++ outptr = outbuf;
++
++ /* Get all the target info */
++ for (i = 0; i < md->map->num_targets; i++) {
++ struct target_type *tt = md->map->targets[i].type;
++ offset_t high = md->map->highs[i];
++
++ if (outptr - outbuf +
++ sizeof(struct dm_target_spec) > param->data_size)
++ return -ENOMEM;
++
++ spec = (struct dm_target_spec *) outptr;
++
++ spec->status = 0;
++ spec->sector_start = sector;
++ spec->length = high - sector + 1;
++ strncpy(spec->target_type, tt->name, sizeof(spec->target_type));
++
++ outptr += sizeof(struct dm_target_spec);
++
++ /* Get the status/table string from the target driver */
++ if (tt->status)
++ tt->status(type, outptr,
++ outbuf + param->data_size - outptr,
++ md->map->targets[i].private);
++ else
++ outptr[0] = '\0';
++
++ outptr += strlen(outptr) + 1;
++ _align(outptr, ALIGNMENT);
++
++ sector = high + 1;
++
++ spec->next = outptr - outbuf;
++ }
++
++ param->target_count = md->map->num_targets;
++ *len = outptr - outbuf;
++
++ return 0;
++}
++
++/*
++ * Return the status of a device as a text string for each
++ * target.
++ */
++static int get_status(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ struct mapped_device *md;
++ int len = 0;
++ int ret;
++ char *outbuf = NULL;
++
++ md = dm_get_name_r(lookup_name(param), lookup_type(param));
++ if (!md)
++ /*
++ * Device not found - returns cleared exists flag.
++ */
++ goto out;
++
++ /* We haven't a clue how long the resultant data will be so
++ just allocate as much as userland has allowed us and make sure
++ we don't overun it */
++ outbuf = kmalloc(param->data_size, GFP_KERNEL);
++ if (!outbuf)
++ goto out;
++ /*
++ * Get the status of all targets
++ */
++ __status(md, param, outbuf, &len);
++
++ /*
++ * Setup the basic dm_ioctl structure.
++ */
++ __info(md, param);
++
++ out:
++ if (md)
++ dm_put_r(md);
++
++ ret = results_to_user(user, param, outbuf, len);
++
++ if (outbuf)
++ kfree(outbuf);
++
++ return ret;
++}
++
++/*
++ * Wait for a device to report an event
++ */
++static int wait_device_event(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ struct mapped_device *md;
++ DECLARE_WAITQUEUE(wq, current);
++
++ md = dm_get_name_r(lookup_name(param), lookup_type(param));
++ if (!md)
++ /*
++ * Device not found - returns cleared exists flag.
++ */
++ goto out;
++ /*
++ * Setup the basic dm_ioctl structure.
++ */
++ __info(md, param);
++
++ /*
++ * Wait for a notification event
++ */
++ set_current_state(TASK_INTERRUPTIBLE);
++ add_wait_queue(&md->map->eventq, &wq);
++
++ dm_put_r(md);
++
++ schedule();
++ set_current_state(TASK_RUNNING);
++
++ out:
++ return results_to_user(user, param, NULL, 0);
++}
++
++/*
++ * Retrieves a list of devices used by a particular dm device.
++ */
++static int dep(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ int count, r;
++ struct mapped_device *md;
++ struct list_head *tmp;
++ size_t len = 0;
++ struct dm_target_deps *deps = NULL;
++
++ md = dm_get_name_r(lookup_name(param), lookup_type(param));
++ if (!md)
++ goto out;
++
++ /*
++ * Setup the basic dm_ioctl structure.
++ */
++ __info(md, param);
++
++ /*
++ * Count the devices.
++ */
++ count = 0;
++ list_for_each(tmp, &md->map->devices)
++ count++;
++
++ /*
++ * Allocate a kernel space version of the dm_target_status
++ * struct.
++ */
++ if (array_too_big(sizeof(*deps), sizeof(*deps->dev), count)) {
++ dm_put_r(md);
++ return -ENOMEM;
++ }
++
++ len = sizeof(*deps) + (sizeof(*deps->dev) * count);
++ deps = kmalloc(len, GFP_KERNEL);
++ if (!deps) {
++ dm_put_r(md);
++ return -ENOMEM;
++ }
++
++ /*
++ * Fill in the devices.
++ */
++ deps->count = count;
++ count = 0;
++ list_for_each(tmp, &md->map->devices) {
++ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
++ deps->dev[count++] = kdev_t_to_nr(dd->dev);
++ }
++ dm_put_r(md);
++
++ out:
++ r = results_to_user(user, param, deps, len);
++
++ kfree(deps);
++ return r;
++}
++
++static int remove(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ int r;
++ struct mapped_device *md;
++
++ md = dm_get_name_w(lookup_name(param), lookup_type(param));
++ if (!md)
++ return -ENXIO;
++
++ r = dm_destroy(md);
++ dm_put_w(md);
++ if (!r)
++ kfree(md);
++
++ return r;
++}
++
++static int suspend(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ int r;
++ struct mapped_device *md;
++
++ md = dm_get_name_w(lookup_name(param), lookup_type(param));
++ if (!md)
++ return -ENXIO;
++
++ r = (param->flags & DM_SUSPEND_FLAG) ? dm_suspend(md) : dm_resume(md);
++ dm_put_w(md);
++
++ return r;
++}
++
++static int reload(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ int r;
++ struct mapped_device *md;
++ struct dm_table *t;
++
++ r = dm_table_create(&t);
++ if (r)
++ return r;
++
++ r = populate_table(t, param);
++ if (r) {
++ dm_table_destroy(t);
++ return r;
++ }
++
++ md = dm_get_name_w(lookup_name(param), lookup_type(param));
++ if (!md) {
++ dm_table_destroy(t);
++ return -ENXIO;
++ }
++
++ r = dm_swap_table(md, t);
++ if (r) {
++ dm_put_w(md);
++ dm_table_destroy(t);
++ return r;
++ }
++
++ dm_set_ro(md, (param->flags & DM_READONLY_FLAG) ? 1 : 0);
++ dm_put_w(md);
++
++ r = info(param, user);
++ return r;
++}
++
++static int rename(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ char *newname = (char *) param + param->data_start;
++
++ if (valid_str(newname, (void *) param,
++ (void *) param + param->data_size) ||
++ dm_set_name(lookup_name(param), lookup_type(param), newname)) {
++ DMWARN("Invalid new logical volume name supplied.");
++ return -EINVAL;
++ }
++
++ return 0;
++}
++
++
++/*-----------------------------------------------------------------
++ * Implementation of open/close/ioctl on the special char
++ * device.
++ *---------------------------------------------------------------*/
++static int ctl_open(struct inode *inode, struct file *file)
++{
++ /* only root can open this */
++ if (!capable(CAP_SYS_ADMIN))
++ return -EACCES;
++
++ MOD_INC_USE_COUNT;
++
++ return 0;
++}
++
++static int ctl_close(struct inode *inode, struct file *file)
++{
++ MOD_DEC_USE_COUNT;
++ return 0;
++}
++
++static ioctl_fn lookup_ioctl(unsigned int cmd)
++{
++ static struct {
++ int cmd;
++ ioctl_fn fn;
++ } _ioctls[] = {
++ {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
++ {DM_REMOVE_ALL_CMD, remove_all},
++ {DM_DEV_CREATE_CMD, create},
++ {DM_DEV_REMOVE_CMD, remove},
++ {DM_DEV_RELOAD_CMD, reload},
++ {DM_DEV_RENAME_CMD, rename},
++ {DM_DEV_SUSPEND_CMD, suspend},
++ {DM_DEV_DEPS_CMD, dep},
++ {DM_DEV_STATUS_CMD, info},
++ {DM_TARGET_STATUS_CMD, get_status},
++ {DM_TARGET_WAIT_CMD, wait_device_event},
++ };
++ static int nelts = sizeof(_ioctls) / sizeof(*_ioctls);
++
++ return (cmd >= nelts) ? NULL : _ioctls[cmd].fn;
++}
++
++/*
++ * As well as checking the version compatibility this always
++ * copies the kernel interface version out.
++ */
++static int check_version(int cmd, struct dm_ioctl *user)
++{
++ uint32_t version[3];
++ int r = 0;
++
++ if (copy_from_user(version, user->version, sizeof(version)))
++ return -EFAULT;
++
++ if ((DM_VERSION_MAJOR != version[0]) ||
++ (DM_VERSION_MINOR < version[1])) {
++ DMWARN("ioctl interface mismatch: "
++ "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
++ DM_VERSION_MAJOR, DM_VERSION_MINOR,
++ DM_VERSION_PATCHLEVEL,
++ version[0], version[1], version[2], cmd);
++ r = -EINVAL;
++ }
++
++ /*
++ * Fill in the kernel version.
++ */
++ version[0] = DM_VERSION_MAJOR;
++ version[1] = DM_VERSION_MINOR;
++ version[2] = DM_VERSION_PATCHLEVEL;
++ if (copy_to_user(user->version, version, sizeof(version)))
++ return -EFAULT;
++
++ return r;
++}
++
++static void free_params(struct dm_ioctl *param)
++{
++ vfree(param);
++}
++
++static int copy_params(struct dm_ioctl *user, struct dm_ioctl **param)
++{
++ struct dm_ioctl tmp, *dmi;
++
++ if (copy_from_user(&tmp, user, sizeof(tmp)))
++ return -EFAULT;
++
++ if (tmp.data_size < sizeof(tmp))
++ return -EINVAL;
++
++ dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
++ if (!dmi)
++ return -ENOMEM;
++
++ if (copy_from_user(dmi, user, tmp.data_size)) {
++ vfree(dmi);
++ return -EFAULT;
++ }
++
++ *param = dmi;
++ return 0;
++}
++
++static int validate_params(uint cmd, struct dm_ioctl *param)
++{
++ /* Unless creating, either name of uuid but not both */
++ if (cmd != DM_DEV_CREATE_CMD) {
++ if ((!*param->uuid && !*param->name) ||
++ (*param->uuid && *param->name)) {
++ DMWARN("one of name or uuid must be supplied");
++ return -EINVAL;
++ }
++ }
++
++ /* Ensure strings are terminated */
++ param->name[DM_NAME_LEN - 1] = '\0';
++ param->uuid[DM_UUID_LEN - 1] = '\0';
++
++ return 0;
++}
++
++static int ctl_ioctl(struct inode *inode, struct file *file,
++ uint command, ulong u)
++{
++
++ int r = 0, cmd;
++ struct dm_ioctl *param;
++ struct dm_ioctl *user = (struct dm_ioctl *) u;
++ ioctl_fn fn = NULL;
++
++ if (_IOC_TYPE(command) != DM_IOCTL)
++ return -ENOTTY;
++
++ cmd = _IOC_NR(command);
++
++ /*
++ * Check the interface version passed in. This also
++ * writes out the kernel's interface version.
++ */
++ r = check_version(cmd, user);
++ if (r)
++ return r;
++
++ /*
++ * Nothing more to do for the version command.
++ */
++ if (cmd == DM_VERSION_CMD)
++ return 0;
++
++ fn = lookup_ioctl(cmd);
++ if (!fn) {
++ DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
++ return -ENOTTY;
++ }
++
++ /*
++ * Copy the parameters into kernel space.
++ */
++ r = copy_params(user, ¶m);
++ if (r)
++ return r;
++
++ r = validate_params(cmd, param);
++ if (r) {
++ free_params(param);
++ return r;
++ }
++
++ r = fn(param, user);
++ free_params(param);
++ return r;
++}
++
++static struct file_operations _ctl_fops = {
++ open: ctl_open,
++ release: ctl_close,
++ ioctl: ctl_ioctl,
++ owner: THIS_MODULE,
++};
++
++static devfs_handle_t _ctl_handle;
++
++static struct miscdevice _dm_misc = {
++ minor: MISC_DYNAMIC_MINOR,
++ name: DM_NAME,
++ fops: &_ctl_fops
++};
++
++/* Create misc character device and link to DM_DIR/control */
++int __init dm_interface_init(void)
++{
++ int r;
++ char rname[64];
++
++ r = misc_register(&_dm_misc);
++ if (r) {
++ DMERR("misc_register failed for control device");
++ return r;
++ }
++
++ r = devfs_generate_path(_dm_misc.devfs_handle, rname + 3,
++ sizeof rname - 3);
++ if (r == -ENOSYS)
++ return 0; /* devfs not present */
++
++ if (r < 0) {
++ DMERR("devfs_generate_path failed for control device");
++ goto failed;
++ }
++
++ strncpy(rname + r, "../", 3);
++ r = devfs_mk_symlink(NULL, DM_DIR "/control",
++ DEVFS_FL_DEFAULT, rname + r, &_ctl_handle, NULL);
++ if (r) {
++ DMERR("devfs_mk_symlink failed for control device");
++ goto failed;
++ }
++ devfs_auto_unregister(_dm_misc.devfs_handle, _ctl_handle);
++
++ DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
++ DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
++ DM_DRIVER_EMAIL);
++ return 0;
++
++ failed:
++ misc_deregister(&_dm_misc);
++ return r;
++}
++
++void dm_interface_exit(void)
++{
++ if (misc_deregister(&_dm_misc) < 0)
++ DMERR("misc_deregister failed for control device");
++}
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.c linux/drivers/md/dm.c
+--- linux-2.4.19-rc1/drivers/md/dm.c Tue Jun 25 22:18:02 2002
++++ linux/drivers/md/dm.c Tue Jun 25 22:22:17 2002
+@@ -266,6 +266,7 @@
+ #define xx(n) {n ## _init, n ## _exit},
+ xx(local)
+ xx(dm_target)
++ xx(dm_interface)
+ #undef xx
+ };
+
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.h linux/drivers/md/dm.h
+--- linux-2.4.19-rc1/drivers/md/dm.h Tue Jun 25 22:18:02 2002
++++ linux/drivers/md/dm.h Tue Jun 25 22:26:00 2002
+@@ -205,4 +205,11 @@
+ return (num > (ULONG_MAX - fixed) / obj);
+ }
+
++/*
++ * The device-mapper can be driven through one of two interfaces;
++ * ioctl or filesystem, depending which patch you have applied.
++ */
++int __init dm_interface_init(void);
++void dm_interface_exit(void);
++
+ #endif
+diff -ruN linux-2.4.19-rc1/include/linux/dm-ioctl.h linux/include/linux/dm-ioctl.h
+--- linux-2.4.19-rc1/include/linux/dm-ioctl.h Thu Jan 1 01:00:00 1970
++++ linux/include/linux/dm-ioctl.h Tue Jun 25 22:18:23 2002
+@@ -0,0 +1,145 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the LGPL.
++ */
++
++#ifndef _LINUX_DM_IOCTL_H
++#define _LINUX_DM_IOCTL_H
++
++#include "device-mapper.h"
++#include "types.h"
++
++/*
++ * Implements a traditional ioctl interface to the device mapper.
++ */
++
++/*
++ * All ioctl arguments consist of a single chunk of memory, with
++ * this structure at the start. If a uuid is specified any
++ * lookup (eg. for a DM_INFO) will be done on that, *not* the
++ * name.
++ */
++struct dm_ioctl {
++ /*
++ * The version number is made up of three parts:
++ * major - no backward or forward compatibility,
++ * minor - only backwards compatible,
++ * patch - both backwards and forwards compatible.
++ *
++ * All clients of the ioctl interface should fill in the
++ * version number of the interface that they were
++ * compiled with.
++ *
++ * All recognised ioctl commands (ie. those that don't
++ * return -ENOTTY) fill out this field, even if the
++ * command failed.
++ */
++ uint32_t version[3]; /* in/out */
++ uint32_t data_size; /* total size of data passed in
++ * including this struct */
++
++ uint32_t data_start; /* offset to start of data
++ * relative to start of this struct */
++
++ uint32_t target_count; /* in/out */
++ uint32_t open_count; /* out */
++ uint32_t flags; /* in/out */
++
++ __kernel_dev_t dev; /* in/out */
++
++ char name[DM_NAME_LEN]; /* device name */
++ char uuid[DM_UUID_LEN]; /* unique identifier for
++ * the block device */
++};
++
++/*
++ * Used to specify tables. These structures appear after the
++ * dm_ioctl.
++ */
++struct dm_target_spec {
++ int32_t status; /* used when reading from kernel only */
++ uint64_t sector_start;
++ uint32_t length;
++
++ /*
++ * Offset in bytes (from the start of this struct) to
++ * next target_spec.
++ */
++ uint32_t next;
++
++ char target_type[DM_MAX_TYPE_NAME];
++
++ /*
++ * Parameter string starts immediately after this object.
++ * Be careful to add padding after string to ensure correct
++ * alignment of subsequent dm_target_spec.
++ */
++};
++
++/*
++ * Used to retrieve the target dependencies.
++ */
++struct dm_target_deps {
++ uint32_t count;
++
++ __kernel_dev_t dev[0]; /* out */
++};
++
++/*
++ * If you change this make sure you make the corresponding change
++ * to dm-ioctl.c:lookup_ioctl()
++ */
++enum {
++ /* Top level cmds */
++ DM_VERSION_CMD = 0,
++ DM_REMOVE_ALL_CMD,
++
++ /* device level cmds */
++ DM_DEV_CREATE_CMD,
++ DM_DEV_REMOVE_CMD,
++ DM_DEV_RELOAD_CMD,
++ DM_DEV_RENAME_CMD,
++ DM_DEV_SUSPEND_CMD,
++ DM_DEV_DEPS_CMD,
++ DM_DEV_STATUS_CMD,
++
++ /* target level cmds */
++ DM_TARGET_STATUS_CMD,
++ DM_TARGET_WAIT_CMD
++};
++
++#define DM_IOCTL 0xfd
++
++#define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
++#define DM_REMOVE_ALL _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
++
++#define DM_DEV_CREATE _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
++#define DM_DEV_REMOVE _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
++#define DM_DEV_RELOAD _IOWR(DM_IOCTL, DM_DEV_RELOAD_CMD, struct dm_ioctl)
++#define DM_DEV_SUSPEND _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
++#define DM_DEV_RENAME _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
++#define DM_DEV_DEPS _IOWR(DM_IOCTL, DM_DEV_DEPS_CMD, struct dm_ioctl)
++#define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
++
++#define DM_TARGET_STATUS _IOWR(DM_IOCTL, DM_TARGET_STATUS_CMD, struct dm_ioctl)
++#define DM_TARGET_WAIT _IOWR(DM_IOCTL, DM_TARGET_WAIT_CMD, struct dm_ioctl)
++
++#define DM_VERSION_MAJOR 1
++#define DM_VERSION_MINOR 0
++#define DM_VERSION_PATCHLEVEL 0
++#define DM_VERSION_EXTRA "-ioctl (2002-06-25)"
++
++/* Status bits */
++#define DM_READONLY_FLAG 0x00000001
++#define DM_SUSPEND_FLAG 0x00000002
++#define DM_EXISTS_FLAG 0x00000004
++#define DM_PERSISTENT_DEV_FLAG 0x00000008
++
++/*
++ * Flag passed into ioctl STATUS command to get table information
++ * rather than current status.
++ */
++#define DM_STATUS_TABLE_FLAG 0x00000010
++
++#endif /* _LINUX_DM_IOCTL_H */
--- /dev/null
+diff -ruN linux-2.4.19-rc1/drivers/md/Makefile linux/drivers/md/Makefile
+--- linux-2.4.19-rc1/drivers/md/Makefile Tue Jun 25 22:18:35 2002
++++ linux/drivers/md/Makefile Tue Jun 25 22:28:32 2002
+@@ -7,7 +7,8 @@
+ export-objs := md.o xor.o dm-table.o dm-target.o
+ list-multi := lvm-mod.o
+ lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
+-dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o
++dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o \
++ dm-linear.o dm-stripe.o
+
+ # Note: link order is important. All raid personalities
+ # and xor.o must come before md.o, as they each initialise
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-linear.c linux/drivers/md/dm-linear.c
+--- linux-2.4.19-rc1/drivers/md/dm-linear.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-linear.c Tue Jun 25 22:28:43 2002
+@@ -0,0 +1,125 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/blkdev.h>
++
++/*
++ * Linear: maps a linear range of a device.
++ */
++struct linear_c {
++ long delta; /* FIXME: we need a signed offset type */
++ long start; /* For display only */
++ struct dm_dev *dev;
++};
++
++/*
++ * Construct a linear mapping: <dev_path> <offset>
++ */
++static int linear_ctr(struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **argv, void **context)
++{
++ struct linear_c *lc;
++ unsigned long start; /* FIXME: unsigned long long */
++ char *end;
++
++ if (argc != 2) {
++ *context = "dm-linear: Not enough arguments";
++ return -EINVAL;
++ }
++
++ lc = kmalloc(sizeof(*lc), GFP_KERNEL);
++ if (lc == NULL) {
++ *context = "dm-linear: Cannot allocate linear context";
++ return -ENOMEM;
++ }
++
++ start = simple_strtoul(argv[1], &end, 10);
++ if (*end) {
++ *context = "dm-linear: Invalid device sector";
++ goto bad;
++ }
++
++ if (dm_table_get_device(t, argv[0], start, l, &lc->dev)) {
++ *context = "dm-linear: Device lookup failed";
++ goto bad;
++ }
++
++ lc->delta = (int) start - (int) b;
++ lc->start = start;
++ *context = lc;
++ return 0;
++
++ bad:
++ kfree(lc);
++ return -EINVAL;
++}
++
++static void linear_dtr(struct dm_table *t, void *c)
++{
++ struct linear_c *lc = (struct linear_c *) c;
++
++ dm_table_put_device(t, lc->dev);
++ kfree(c);
++}
++
++static int linear_map(struct buffer_head *bh, int rw, void *context)
++{
++ struct linear_c *lc = (struct linear_c *) context;
++
++ bh->b_rdev = lc->dev->dev;
++ bh->b_rsector = bh->b_rsector + lc->delta;
++
++ return 1;
++}
++
++static int linear_status(status_type_t type, char *result, int maxlen,
++ void *context)
++{
++ struct linear_c *lc = (struct linear_c *) context;
++
++ switch (type) {
++ case STATUSTYPE_INFO:
++ result[0] = '\0';
++ break;
++
++ case STATUSTYPE_TABLE:
++ snprintf(result, maxlen, "%s %ld", kdevname(lc->dev->dev),
++ lc->start);
++ break;
++ }
++ return 0;
++}
++
++static struct target_type linear_target = {
++ name: "linear",
++ module: THIS_MODULE,
++ ctr: linear_ctr,
++ dtr: linear_dtr,
++ map: linear_map,
++ status: linear_status,
++};
++
++int __init dm_linear_init(void)
++{
++ int r = dm_register_target(&linear_target);
++
++ if (r < 0)
++ DMERR("linear: register failed %d", r);
++
++ return r;
++}
++
++void dm_linear_exit(void)
++{
++ int r = dm_unregister_target(&linear_target);
++
++ if (r < 0)
++ DMERR("linear: unregister failed %d", r);
++}
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-stripe.c linux/drivers/md/dm-stripe.c
+--- linux-2.4.19-rc1/drivers/md/dm-stripe.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-stripe.c Tue Jun 25 22:28:43 2002
+@@ -0,0 +1,234 @@
++/*
++ * Copyright (C) 2001 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/blkdev.h>
++
++struct stripe {
++ struct dm_dev *dev;
++ offset_t physical_start;
++};
++
++struct stripe_c {
++ offset_t logical_start;
++ uint32_t stripes;
++
++ /* The size of this target / num. stripes */
++ uint32_t stripe_width;
++
++ /* stripe chunk size */
++ uint32_t chunk_shift;
++ offset_t chunk_mask;
++
++ struct stripe stripe[0];
++};
++
++static inline struct stripe_c *alloc_context(int stripes)
++{
++ size_t len;
++
++ if (array_too_big(sizeof(struct stripe_c), sizeof(struct stripe),
++ stripes))
++ return NULL;
++
++ len = sizeof(struct stripe_c) + (sizeof(struct stripe) * stripes);
++
++ return kmalloc(len, GFP_KERNEL);
++}
++
++/*
++ * Parse a single <dev> <sector> pair
++ */
++static int get_stripe(struct dm_table *t, struct stripe_c *sc,
++ int stripe, char **argv)
++{
++ char *end;
++ unsigned long start;
++
++ start = simple_strtoul(argv[1], &end, 10);
++ if (*end)
++ return -EINVAL;
++
++ if (dm_table_get_device(t, argv[0], start, sc->stripe_width,
++ &sc->stripe[stripe].dev))
++ return -ENXIO;
++
++ sc->stripe[stripe].physical_start = start;
++ return 0;
++}
++
++/*
++ * Construct a striped mapping.
++ * <number of stripes> <chunk size (2^^n)> [<dev_path> <offset>]+
++ */
++static int stripe_ctr(struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **argv, void **context)
++{
++ struct stripe_c *sc;
++ uint32_t stripes;
++ uint32_t chunk_size;
++ char *end;
++ int r, i;
++
++ if (argc < 2) {
++ *context = "dm-stripe: Not enough arguments";
++ return -EINVAL;
++ }
++
++ stripes = simple_strtoul(argv[0], &end, 10);
++ if (*end) {
++ *context = "dm-stripe: Invalid stripe count";
++ return -EINVAL;
++ }
++
++ chunk_size = simple_strtoul(argv[1], &end, 10);
++ if (*end) {
++ *context = "dm-stripe: Invalid chunk_size";
++ return -EINVAL;
++ }
++
++ if (l % stripes) {
++ *context = "dm-stripe: Target length not divisable by "
++ "number of stripes";
++ return -EINVAL;
++ }
++
++ sc = alloc_context(stripes);
++ if (!sc) {
++ *context = "dm-stripe: Memory allocation for striped context "
++ "failed";
++ return -ENOMEM;
++ }
++
++ sc->logical_start = b;
++ sc->stripes = stripes;
++ sc->stripe_width = l / stripes;
++
++ /*
++ * chunk_size is a power of two
++ */
++ if (!chunk_size || (chunk_size & (chunk_size - 1))) {
++ *context = "dm-stripe: Invalid chunk size";
++ kfree(sc);
++ return -EINVAL;
++ }
++
++ sc->chunk_mask = chunk_size - 1;
++ for (sc->chunk_shift = 0; chunk_size; sc->chunk_shift++)
++ chunk_size >>= 1;
++ sc->chunk_shift--;
++
++ /*
++ * Get the stripe destinations.
++ */
++ for (i = 0; i < stripes; i++) {
++ if (argc < 2) {
++ *context = "dm-stripe: Not enough destinations "
++ "specified";
++ kfree(sc);
++ return -EINVAL;
++ }
++
++ argv += 2;
++
++ r = get_stripe(t, sc, i, argv);
++ if (r < 0) {
++ *context = "dm-stripe: Couldn't parse stripe "
++ "destination";
++ while (i--)
++ dm_table_put_device(t, sc->stripe[i].dev);
++ kfree(sc);
++ return r;
++ }
++ }
++
++ *context = sc;
++ return 0;
++}
++
++static void stripe_dtr(struct dm_table *t, void *c)
++{
++ unsigned int i;
++ struct stripe_c *sc = (struct stripe_c *) c;
++
++ for (i = 0; i < sc->stripes; i++)
++ dm_table_put_device(t, sc->stripe[i].dev);
++
++ kfree(sc);
++}
++
++static int stripe_map(struct buffer_head *bh, int rw, void *context)
++{
++ struct stripe_c *sc = (struct stripe_c *) context;
++
++ offset_t offset = bh->b_rsector - sc->logical_start;
++ uint32_t chunk = (uint32_t) (offset >> sc->chunk_shift);
++ uint32_t stripe = chunk % sc->stripes; /* 32bit modulus */
++ chunk = chunk / sc->stripes;
++
++ bh->b_rdev = sc->stripe[stripe].dev->dev;
++ bh->b_rsector = sc->stripe[stripe].physical_start +
++ (chunk << sc->chunk_shift) + (offset & sc->chunk_mask);
++ return 1;
++}
++
++static int stripe_status(status_type_t type, char *result, int maxlen,
++ void *context)
++{
++ struct stripe_c *sc = (struct stripe_c *) context;
++ int offset;
++ int i;
++
++ switch (type) {
++ case STATUSTYPE_INFO:
++ result[0] = '\0';
++ break;
++
++ case STATUSTYPE_TABLE:
++ offset = snprintf(result, maxlen, "%d %ld",
++ sc->stripes, sc->chunk_mask + 1);
++ for (i = 0; i < sc->stripes; i++) {
++ offset +=
++ snprintf(result + offset, maxlen - offset,
++ " %s %ld",
++ kdevname(sc->stripe[i].dev->dev),
++ sc->stripe[i].physical_start);
++ }
++ break;
++ }
++ return 0;
++}
++
++static struct target_type stripe_target = {
++ name: "striped",
++ module: THIS_MODULE,
++ ctr: stripe_ctr,
++ dtr: stripe_dtr,
++ map: stripe_map,
++ status: stripe_status,
++};
++
++int __init dm_stripe_init(void)
++{
++ int r;
++
++ r = dm_register_target(&stripe_target);
++ if (r < 0)
++ DMWARN("striped target registration failed");
++
++ return r;
++}
++
++void dm_stripe_exit(void)
++{
++ if (dm_unregister_target(&stripe_target))
++ DMWARN("striped target unregistration failed");
++
++ return;
++}
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.c linux/drivers/md/dm.c
+--- linux-2.4.19-rc1/drivers/md/dm.c Tue Jun 25 22:22:17 2002
++++ linux/drivers/md/dm.c Tue Jun 25 22:30:30 2002
+@@ -266,6 +266,8 @@
+ #define xx(n) {n ## _init, n ## _exit},
+ xx(local)
+ xx(dm_target)
++ xx(dm_linear)
++ xx(dm_stripe)
+ xx(dm_interface)
+ #undef xx
+ };
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.h linux/drivers/md/dm.h
+--- linux-2.4.19-rc1/drivers/md/dm.h Tue Jun 25 22:26:00 2002
++++ linux/drivers/md/dm.h Tue Jun 25 22:30:03 2002
+@@ -212,4 +212,14 @@
+ int __init dm_interface_init(void);
+ void dm_interface_exit(void);
+
++/*
++ * Targets for linear and striped mappings
++ */
++
++int dm_linear_init(void);
++void dm_linear_exit(void);
++
++int dm_stripe_init(void);
++void dm_stripe_exit(void);
++
+ #endif
--- /dev/null
+diff -ruN linux-2.4.19-rc1/drivers/md/Makefile linux/drivers/md/Makefile
+--- linux-2.4.19-rc1/drivers/md/Makefile Tue Jun 25 22:28:32 2002
++++ linux/drivers/md/Makefile Tue Jun 25 23:12:36 2002
+@@ -4,11 +4,12 @@
+
+ O_TARGET := mddev.o
+
+-export-objs := md.o xor.o dm-table.o dm-target.o
++export-objs := md.o xor.o dm-table.o dm-target.o kcopyd.o
+ list-multi := lvm-mod.o
+ lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
+ dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o \
+- dm-linear.o dm-stripe.o
++ dm-linear.o dm-stripe.o dm-snapshot.o dm-exception-store.o \
++ kcopyd.o
+
+ # Note: link order is important. All raid personalities
+ # and xor.o must come before md.o, as they each initialise
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-exception-store.c linux/drivers/md/dm-exception-store.c
+--- linux-2.4.19-rc1/drivers/md/dm-exception-store.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-exception-store.c Tue Jun 25 22:31:08 2002
+@@ -0,0 +1,727 @@
++/*
++ * dm-snapshot.c
++ *
++ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm-snapshot.h"
++#include "kcopyd.h"
++#include <linux/mm.h>
++#include <linux/pagemap.h>
++
++#define SECTOR_SIZE 512
++#define SECTOR_SHIFT 9
++
++/*-----------------------------------------------------------------
++ * Persistent snapshots, by persistent we mean that the snapshot
++ * will survive a reboot.
++ *---------------------------------------------------------------*/
++
++/*
++ * We need to store a record of which parts of the origin have
++ * been copied to the snapshot device. The snapshot code
++ * requires that we copy exception chunks to chunk aligned areas
++ * of the COW store. It makes sense therefore, to store the
++ * metadata in chunk size blocks.
++ *
++ * There is no backward or forward compatibility implemented,
++ * snapshots with different disk versions than the kernel will
++ * not be usable. It is expected that "lvcreate" will blank out
++ * the start of a fresh COW device before calling the snapshot
++ * constructor.
++ *
++ * The first chunk of the COW device just contains the header.
++ * After this there is a chunk filled with exception metadata,
++ * followed by as many exception chunks as can fit in the
++ * metadata areas.
++ *
++ * All on disk structures are in little-endian format. The end
++ * of the exceptions info is indicated by an exception with a
++ * new_chunk of 0, which is invalid since it would point to the
++ * header chunk.
++ */
++
++/*
++ * Magic for persistent snapshots: "SnAp" - Feeble isn't it.
++ */
++#define SNAP_MAGIC 0x70416e53
++
++/*
++ * The on-disk version of the metadata.
++ */
++#define SNAPSHOT_DISK_VERSION 1
++
++struct disk_header {
++ uint32_t magic;
++
++ /*
++ * Is this snapshot valid. There is no way of recovering
++ * an invalid snapshot.
++ */
++ int valid;
++
++ /*
++ * Simple, incrementing version. no backward
++ * compatibility.
++ */
++ uint32_t version;
++
++ /* In sectors */
++ uint32_t chunk_size;
++};
++
++struct disk_exception {
++ uint64_t old_chunk;
++ uint64_t new_chunk;
++};
++
++struct commit_callback {
++ void (*callback)(void *, int success);
++ void *context;
++};
++
++/*
++ * The top level structure for a persistent exception store.
++ */
++struct pstore {
++ struct dm_snapshot *snap; /* up pointer to my snapshot */
++ int version;
++ int valid;
++ uint32_t chunk_size;
++ uint32_t exceptions_per_area;
++
++ /*
++ * Now that we have an asynchronous kcopyd there is no
++ * need for large chunk sizes, so it wont hurt to have a
++ * whole chunks worth of metadata in memory at once.
++ */
++ void *area;
++ struct kiobuf *iobuf;
++
++ /*
++ * Used to keep track of which metadata area the data in
++ * 'chunk' refers to.
++ */
++ uint32_t current_area;
++
++ /*
++ * The next free chunk for an exception.
++ */
++ uint32_t next_free;
++
++ /*
++ * The index of next free exception in the current
++ * metadata area.
++ */
++ uint32_t current_committed;
++
++ atomic_t pending_count;
++ uint32_t callback_count;
++ struct commit_callback *callbacks;
++};
++
++/*
++ * For performance reasons we want to defer writing a committed
++ * exceptions metadata to disk so that we can amortise away this
++ * exensive operation.
++ *
++ * For the initial version of this code we will remain with
++ * synchronous io. There are some deadlock issues with async
++ * that I haven't yet worked out.
++ */
++static int do_io(int rw, struct kcopyd_region *where, struct kiobuf *iobuf)
++{
++ int i, sectors_per_block, nr_blocks, start;
++ int blocksize = get_hardsect_size(where->dev);
++ int status;
++
++ sectors_per_block = blocksize / SECTOR_SIZE;
++
++ nr_blocks = where->count / sectors_per_block;
++ start = where->sector / sectors_per_block;
++
++ for (i = 0; i < nr_blocks; i++)
++ iobuf->blocks[i] = start++;
++
++ iobuf->length = where->count << 9;
++ iobuf->locked = 1;
++
++ status = brw_kiovec(rw, 1, &iobuf, where->dev, iobuf->blocks,
++ blocksize);
++ if (status != (where->count << 9))
++ return -EIO;
++
++ return 0;
++}
++
++#if LINUX_VERSION_CODE < KERNEL_VERSION ( 2, 4, 19)
++/*
++ * FIXME: Remove once 2.4.19 has been released.
++ */
++struct page *vmalloc_to_page(void *vmalloc_addr)
++{
++ unsigned long addr = (unsigned long) vmalloc_addr;
++ struct page *page = NULL;
++ pmd_t *pmd;
++ pte_t *pte;
++ pgd_t *pgd;
++
++ pgd = pgd_offset_k(addr);
++ if (!pgd_none(*pgd)) {
++ pmd = pmd_offset(pgd, addr);
++ if (!pmd_none(*pmd)) {
++ pte = pte_offset(pmd, addr);
++ if (pte_present(*pte)) {
++ page = pte_page(*pte);
++ }
++ }
++ }
++ return page;
++}
++#endif
++
++static int allocate_iobuf(struct pstore *ps)
++{
++ size_t i, r = -ENOMEM, len, nr_pages;
++ struct page *page;
++
++ len = ps->chunk_size << SECTOR_SHIFT;
++
++ /*
++ * Allocate the chunk_size block of memory that will hold
++ * a single metadata area.
++ */
++ ps->area = vmalloc(len);
++ if (!ps->area)
++ return r;
++
++ if (alloc_kiovec(1, &ps->iobuf))
++ goto bad;
++
++ if (alloc_kiobuf_bhs(ps->iobuf))
++ goto bad;
++
++ nr_pages = ps->chunk_size / (PAGE_SIZE / SECTOR_SIZE);
++ r = expand_kiobuf(ps->iobuf, nr_pages);
++ if (r)
++ goto bad;
++
++ /*
++ * We lock the pages for ps->area into memory since they'll be
++ * doing a lot of io.
++ */
++ for (i = 0; i < nr_pages; i++) {
++ page = vmalloc_to_page(ps->area + (i * PAGE_SIZE));
++ LockPage(page);
++ ps->iobuf->maplist[i] = page;
++ ps->iobuf->nr_pages++;
++ }
++
++ ps->iobuf->nr_pages = nr_pages;
++ ps->iobuf->offset = 0;
++
++ return 0;
++
++ bad:
++ if (ps->iobuf)
++ free_kiovec(1, &ps->iobuf);
++
++ if (ps->area)
++ vfree(ps->area);
++ ps->iobuf = NULL;
++ return r;
++}
++
++static void free_iobuf(struct pstore *ps)
++{
++ int i;
++
++ for (i = 0; i < ps->iobuf->nr_pages; i++)
++ UnlockPage(ps->iobuf->maplist[i]);
++ ps->iobuf->locked = 0;
++
++ free_kiovec(1, &ps->iobuf);
++ vfree(ps->area);
++}
++
++/*
++ * Read or write a chunk aligned and sized block of data from a device.
++ */
++static int chunk_io(struct pstore *ps, uint32_t chunk, int rw)
++{
++ int r;
++ struct kcopyd_region where;
++
++ where.dev = ps->snap->cow->dev;
++ where.sector = ps->chunk_size * chunk;
++ where.count = ps->chunk_size;
++
++ r = do_io(rw, &where, ps->iobuf);
++ if (r)
++ return r;
++
++ return 0;
++}
++
++/*
++ * Read or write a metadata area. Remembering to skip the first
++ * chunk which holds the header.
++ */
++static int area_io(struct pstore *ps, uint32_t area, int rw)
++{
++ int r;
++ uint32_t chunk;
++
++ /* convert a metadata area index to a chunk index */
++ chunk = 1 + ((ps->exceptions_per_area + 1) * area);
++
++ r = chunk_io(ps, chunk, rw);
++ if (r)
++ return r;
++
++ ps->current_area = area;
++ return 0;
++}
++
++static int zero_area(struct pstore *ps, uint32_t area)
++{
++ memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
++ return area_io(ps, area, WRITE);
++}
++
++static int read_header(struct pstore *ps, int *new_snapshot)
++{
++ int r;
++ struct disk_header *dh;
++
++ r = chunk_io(ps, 0, READ);
++ if (r)
++ return r;
++
++ dh = (struct disk_header *) ps->area;
++
++ if (dh->magic == 0) {
++ *new_snapshot = 1;
++
++ } else if (dh->magic == SNAP_MAGIC) {
++ *new_snapshot = 0;
++ ps->valid = dh->valid;
++ ps->version = dh->version;
++ ps->chunk_size = dh->chunk_size;
++
++ } else {
++ DMWARN("Invalid/corrupt snapshot");
++ r = -ENXIO;
++ }
++
++ return r;
++}
++
++static int write_header(struct pstore *ps)
++{
++ struct disk_header *dh;
++
++ memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
++
++ dh = (struct disk_header *) ps->area;
++ dh->magic = SNAP_MAGIC;
++ dh->valid = ps->valid;
++ dh->version = ps->version;
++ dh->chunk_size = ps->chunk_size;
++
++ return chunk_io(ps, 0, WRITE);
++}
++
++/*
++ * Access functions for the disk exceptions, these do the endian conversions.
++ */
++static struct disk_exception *get_exception(struct pstore *ps, uint32_t index)
++{
++ if (index >= ps->exceptions_per_area)
++ return NULL;
++
++ return ((struct disk_exception *) ps->area) + index;
++}
++
++static int read_exception(struct pstore *ps,
++ uint32_t index, struct disk_exception *result)
++{
++ struct disk_exception *e;
++
++ e = get_exception(ps, index);
++ if (!e)
++ return -EINVAL;
++
++ /* copy it */
++ result->old_chunk = le64_to_cpu(e->old_chunk);
++ result->new_chunk = le64_to_cpu(e->new_chunk);
++
++ return 0;
++}
++
++static int write_exception(struct pstore *ps,
++ uint32_t index, struct disk_exception *de)
++{
++ struct disk_exception *e;
++
++ e = get_exception(ps, index);
++ if (!e)
++ return -EINVAL;
++
++ /* copy it */
++ e->old_chunk = cpu_to_le64(de->old_chunk);
++ e->new_chunk = cpu_to_le64(de->new_chunk);
++
++ return 0;
++}
++
++/*
++ * Registers the exceptions that are present in the current area.
++ * 'full' is filled in to indicate if the area has been
++ * filled.
++ */
++static int insert_exceptions(struct pstore *ps, int *full)
++{
++ int i, r;
++ struct disk_exception de;
++
++ /* presume the area is full */
++ *full = 1;
++
++ for (i = 0; i < ps->exceptions_per_area; i++) {
++ r = read_exception(ps, i, &de);
++
++ if (r)
++ return r;
++
++ /*
++ * If the new_chunk is pointing at the start of
++ * the COW device, where the first metadata area
++ * is we know that we've hit the end of the
++ * exceptions. Therefore the area is not full.
++ */
++ if (de.new_chunk == 0LL) {
++ ps->current_committed = i;
++ *full = 0;
++ break;
++ }
++
++ /*
++ * Keep track of the start of the free chunks.
++ */
++ if (ps->next_free <= de.new_chunk)
++ ps->next_free = de.new_chunk + 1;
++
++ /*
++ * Otherwise we add the exception to the snapshot.
++ */
++ r = dm_add_exception(ps->snap, de.old_chunk, de.new_chunk);
++ if (r)
++ return r;
++ }
++
++ return 0;
++}
++
++static int read_exceptions(struct pstore *ps)
++{
++ uint32_t area;
++ int r, full = 1;
++
++ /*
++ * Keeping reading chunks and inserting exceptions until
++ * we find a partially full area.
++ */
++ for (area = 0; full; area++) {
++ r = area_io(ps, area, READ);
++ if (r)
++ return r;
++
++ r = insert_exceptions(ps, &full);
++ if (r)
++ return r;
++
++ area++;
++ }
++
++ return 0;
++}
++
++static inline struct pstore *get_info(struct exception_store *store)
++{
++ return (struct pstore *) store->context;
++}
++
++static int persistent_percentfull(struct exception_store *store)
++{
++ struct pstore *ps = get_info(store);
++ return (ps->next_free * store->snap->chunk_size * 100) /
++ get_dev_size(store->snap->cow->dev);
++}
++
++static void persistent_destroy(struct exception_store *store)
++{
++ struct pstore *ps = get_info(store);
++
++ vfree(ps->callbacks);
++ free_iobuf(ps);
++ kfree(ps);
++}
++
++static int persistent_prepare(struct exception_store *store,
++ struct exception *e)
++{
++ struct pstore *ps = get_info(store);
++ uint32_t stride;
++ offset_t size = get_dev_size(store->snap->cow->dev);
++
++ /* Is there enough room ? */
++ if (size <= (ps->next_free * store->snap->chunk_size))
++ return -ENOSPC;
++
++ e->new_chunk = ps->next_free;
++
++ /*
++ * Move onto the next free pending, making sure to take
++ * into account the location of the metadata chunks.
++ */
++ stride = (ps->exceptions_per_area + 1);
++ if (!(++ps->next_free % stride))
++ ps->next_free++;
++
++ atomic_inc(&ps->pending_count);
++ return 0;
++}
++
++static void persistent_commit(struct exception_store *store,
++ struct exception *e,
++ void (*callback) (void *, int success),
++ void *callback_context)
++{
++ int r, i;
++ struct pstore *ps = get_info(store);
++ struct disk_exception de;
++ struct commit_callback *cb;
++
++ de.old_chunk = e->old_chunk;
++ de.new_chunk = e->new_chunk;
++ write_exception(ps, ps->current_committed++, &de);
++
++ /*
++ * Add the callback to the back of the array. This code
++ * is the only place where the callback array is
++ * manipulated, and we know that it will never be called
++ * multiple times concurrently.
++ */
++ cb = ps->callbacks + ps->callback_count++;
++ cb->callback = callback;
++ cb->context = callback_context;
++
++ /*
++ * If there are no more exceptions in flight, or we have
++ * filled this metadata area we commit the exceptions to
++ * disk.
++ */
++ if (atomic_dec_and_test(&ps->pending_count) ||
++ (ps->current_committed == ps->exceptions_per_area)) {
++ r = area_io(ps, ps->current_area, WRITE);
++ if (r)
++ ps->valid = 0;
++
++ for (i = 0; i < ps->callback_count; i++) {
++ cb = ps->callbacks + i;
++ cb->callback(cb->context, r == 0 ? 1 : 0);
++ }
++
++ ps->callback_count = 0;
++ }
++
++ /*
++ * Have we completely filled the current area ?
++ */
++ if (ps->current_committed == ps->exceptions_per_area) {
++ ps->current_committed = 0;
++ r = zero_area(ps, ps->current_area + 1);
++ if (r)
++ ps->valid = 0;
++ }
++}
++
++static void persistent_drop(struct exception_store *store)
++{
++ struct pstore *ps = get_info(store);
++
++ ps->valid = 0;
++ if (write_header(ps))
++ DMWARN("write header failed");
++}
++
++int dm_create_persistent(struct exception_store *store, uint32_t chunk_size)
++{
++ int r, new_snapshot;
++ struct pstore *ps;
++
++ /* allocate the pstore */
++ ps = kmalloc(sizeof(*ps), GFP_KERNEL);
++ if (!ps)
++ return -ENOMEM;
++
++ ps->snap = store->snap;
++ ps->valid = 1;
++ ps->version = SNAPSHOT_DISK_VERSION;
++ ps->chunk_size = chunk_size;
++ ps->exceptions_per_area = (chunk_size << SECTOR_SHIFT) /
++ sizeof(struct disk_exception);
++ ps->next_free = 2; /* skipping the header and first area */
++ ps->current_committed = 0;
++
++ r = allocate_iobuf(ps);
++ if (r)
++ goto bad;
++
++ /*
++ * Allocate space for all the callbacks.
++ */
++ ps->callback_count = 0;
++ atomic_set(&ps->pending_count, 0);
++ ps->callbacks = vcalloc(ps->exceptions_per_area,
++ sizeof(*ps->callbacks));
++
++ if (!ps->callbacks)
++ goto bad;
++
++ /*
++ * Read the snapshot header.
++ */
++ r = read_header(ps, &new_snapshot);
++ if (r)
++ goto bad;
++
++ /*
++ * Do we need to setup a new snapshot ?
++ */
++ if (new_snapshot) {
++ r = write_header(ps);
++ if (r) {
++ DMWARN("write_header failed");
++ goto bad;
++ }
++
++ r = zero_area(ps, 0);
++ if (r) {
++ DMWARN("zero_area(0) failed");
++ goto bad;
++ }
++
++ } else {
++ /*
++ * Sanity checks.
++ */
++ if (ps->chunk_size != chunk_size) {
++ DMWARN("chunk size for existing snapshot different "
++ "from that requested");
++ r = -EINVAL;
++ goto bad;
++ }
++
++ if (ps->version != SNAPSHOT_DISK_VERSION) {
++ DMWARN("unable to handle snapshot disk version %d",
++ ps->version);
++ r = -EINVAL;
++ goto bad;
++ }
++
++ /*
++ * Read the metadata.
++ */
++ r = read_exceptions(ps);
++ if (r)
++ goto bad;
++ }
++
++ store->destroy = persistent_destroy;
++ store->prepare_exception = persistent_prepare;
++ store->commit_exception = persistent_commit;
++ store->drop_snapshot = persistent_drop;
++ store->percent_full = persistent_percentfull;
++ store->context = ps;
++
++ return r;
++
++ bad:
++ if (ps) {
++ if (ps->callbacks)
++ vfree(ps->callbacks);
++
++ if (ps->iobuf)
++ free_iobuf(ps);
++
++ kfree(ps);
++ }
++ return r;
++}
++
++/*-----------------------------------------------------------------
++ * Implementation of the store for non-persistent snapshots.
++ *---------------------------------------------------------------*/
++struct transient_c {
++ offset_t next_free;
++};
++
++void transient_destroy(struct exception_store *store)
++{
++ kfree(store->context);
++}
++
++int transient_prepare(struct exception_store *store, struct exception *e)
++{
++ struct transient_c *tc = (struct transient_c *) store->context;
++ offset_t size = get_dev_size(store->snap->cow->dev);
++
++ if (size < (tc->next_free + store->snap->chunk_size))
++ return -1;
++
++ e->new_chunk = sector_to_chunk(store->snap, tc->next_free);
++ tc->next_free += store->snap->chunk_size;
++
++ return 0;
++}
++
++void transient_commit(struct exception_store *store,
++ struct exception *e,
++ void (*callback) (void *, int success),
++ void *callback_context)
++{
++ /* Just succeed */
++ callback(callback_context, 1);
++}
++
++static int transient_percentfull(struct exception_store *store)
++{
++ struct transient_c *tc = (struct transient_c *) store->context;
++ return (tc->next_free * 100) / get_dev_size(store->snap->cow->dev);
++}
++
++int dm_create_transient(struct exception_store *store,
++ struct dm_snapshot *s, int blocksize, void **error)
++{
++ struct transient_c *tc;
++
++ memset(store, 0, sizeof(*store));
++ store->destroy = transient_destroy;
++ store->prepare_exception = transient_prepare;
++ store->commit_exception = transient_commit;
++ store->percent_full = transient_percentfull;
++ store->snap = s;
++
++ tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
++ if (!tc)
++ return -ENOMEM;
++
++ tc->next_free = 0;
++ store->context = tc;
++
++ return 0;
++}
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-snapshot.c linux/drivers/md/dm-snapshot.c
+--- linux-2.4.19-rc1/drivers/md/dm-snapshot.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-snapshot.c Tue Jun 25 22:31:08 2002
+@@ -0,0 +1,1182 @@
++/*
++ * dm-snapshot.c
++ *
++ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/slab.h>
++#include <linux/list.h>
++#include <linux/fs.h>
++#include <linux/blkdev.h>
++#include <linux/mempool.h>
++#include <linux/device-mapper.h>
++
++#include "dm-snapshot.h"
++#include "kcopyd.h"
++
++/*
++ * FIXME: Remove this before release.
++ */
++#if 0
++#define DMDEBUG(x...) DMWARN( ## x)
++#else
++#define DMDEBUG(x...)
++#endif
++
++/*
++ * The percentage increment we will wake up users at
++ */
++#define WAKE_UP_PERCENT 5
++
++/*
++ * Hard sector size used all over the kernel
++ */
++#define SECTOR_SIZE 512
++
++/*
++ * kcopyd priority of snapshot operations
++ */
++#define SNAPSHOT_COPY_PRIORITY 2
++
++struct pending_exception {
++ struct exception e;
++
++ /*
++ * Origin buffers waiting for this to complete are held
++ * in a list (using b_reqnext).
++ */
++ struct buffer_head *origin_bhs;
++ struct buffer_head *snapshot_bhs;
++
++ /*
++ * Other pending_exceptions that are processing this
++ * chunk. When this list is empty, we know we can
++ * complete the origins.
++ */
++ struct list_head siblings;
++
++ /* Pointer back to snapshot context */
++ struct dm_snapshot *snap;
++
++ /*
++ * 1 indicates the exception has already been sent to
++ * kcopyd.
++ */
++ int started;
++};
++
++/*
++ * Hash table mapping origin volumes to lists of snapshots and
++ * a lock to protect it
++ */
++static kmem_cache_t *exception_cache;
++static kmem_cache_t *pending_cache;
++static mempool_t *pending_pool;
++
++/*
++ * One of these per registered origin, held in the snapshot_origins hash
++ */
++struct origin {
++ /* The origin device */
++ kdev_t dev;
++
++ struct list_head hash_list;
++
++ /* List of snapshots for this origin */
++ struct list_head snapshots;
++};
++
++/*
++ * Size of the hash table for origin volumes. If we make this
++ * the size of the minors list then it should be nearly perfect
++ */
++#define ORIGIN_HASH_SIZE 256
++#define ORIGIN_MASK 0xFF
++static struct list_head *_origins;
++static struct rw_semaphore _origins_lock;
++
++static int init_origin_hash(void)
++{
++ int i;
++
++ _origins = kmalloc(ORIGIN_HASH_SIZE * sizeof(struct list_head),
++ GFP_KERNEL);
++ if (!_origins) {
++ DMERR("Device mapper: Snapshot: unable to allocate memory");
++ return -ENOMEM;
++ }
++
++ for (i = 0; i < ORIGIN_HASH_SIZE; i++)
++ INIT_LIST_HEAD(_origins + i);
++ init_rwsem(&_origins_lock);
++
++ return 0;
++}
++
++static void exit_origin_hash(void)
++{
++ kfree(_origins);
++}
++
++static inline unsigned int origin_hash(kdev_t dev)
++{
++ return MINOR(dev) & ORIGIN_MASK;
++}
++
++static struct origin *__lookup_origin(kdev_t origin)
++{
++ struct list_head *slist;
++ struct list_head *ol;
++ struct origin *o;
++
++ ol = &_origins[origin_hash(origin)];
++ list_for_each(slist, ol) {
++ o = list_entry(slist, struct origin, hash_list);
++
++ if (o->dev == origin)
++ return o;
++ }
++
++ return NULL;
++}
++
++static void __insert_origin(struct origin *o)
++{
++ struct list_head *sl = &_origins[origin_hash(o->dev)];
++ list_add_tail(&o->hash_list, sl);
++}
++
++/*
++ * Make a note of the snapshot and its origin so we can look it
++ * up when the origin has a write on it.
++ */
++static int register_snapshot(struct dm_snapshot *snap)
++{
++ struct origin *o;
++ kdev_t dev = snap->origin->dev;
++
++ down_write(&_origins_lock);
++ o = __lookup_origin(dev);
++
++ if (!o) {
++ /* New origin */
++ o = kmalloc(sizeof(*o), GFP_KERNEL);
++ if (!o) {
++ up_write(&_origins_lock);
++ return -ENOMEM;
++ }
++
++ /* Initialise the struct */
++ INIT_LIST_HEAD(&o->snapshots);
++ o->dev = dev;
++
++ __insert_origin(o);
++ }
++
++ list_add_tail(&snap->list, &o->snapshots);
++
++ up_write(&_origins_lock);
++ return 0;
++}
++
++static void unregister_snapshot(struct dm_snapshot *s)
++{
++ struct origin *o;
++
++ down_write(&_origins_lock);
++ o = __lookup_origin(s->origin->dev);
++
++ list_del(&s->list);
++ if (list_empty(&o->snapshots)) {
++ list_del(&o->hash_list);
++ kfree(o);
++ }
++
++ up_write(&_origins_lock);
++}
++
++/*
++ * Implementation of the exception hash tables.
++ */
++static int init_exception_table(struct exception_table *et, uint32_t size)
++{
++ int i;
++
++ et->hash_mask = size - 1;
++ et->table = vcalloc(size, sizeof(struct list_head));
++ if (!et->table)
++ return -ENOMEM;
++
++ for (i = 0; i < size; i++)
++ INIT_LIST_HEAD(et->table + i);
++
++ return 0;
++}
++
++static void exit_exception_table(struct exception_table *et, kmem_cache_t *mem)
++{
++ struct list_head *slot, *entry, *temp;
++ struct exception *ex;
++ int i, size;
++
++ size = et->hash_mask + 1;
++ for (i = 0; i < size; i++) {
++ slot = et->table + i;
++
++ list_for_each_safe(entry, temp, slot) {
++ ex = list_entry(entry, struct exception, hash_list);
++ kmem_cache_free(mem, ex);
++ }
++ }
++
++ vfree(et->table);
++}
++
++/*
++ * FIXME: check how this hash fn is performing.
++ */
++static inline uint32_t exception_hash(struct exception_table *et, chunk_t chunk)
++{
++ return chunk & et->hash_mask;
++}
++
++static void insert_exception(struct exception_table *eh, struct exception *e)
++{
++ struct list_head *l = &eh->table[exception_hash(eh, e->old_chunk)];
++ list_add(&e->hash_list, l);
++}
++
++static inline void remove_exception(struct exception *e)
++{
++ list_del(&e->hash_list);
++}
++
++/*
++ * Return the exception data for a sector, or NULL if not
++ * remapped.
++ */
++static struct exception *lookup_exception(struct exception_table *et,
++ chunk_t chunk)
++{
++ struct list_head *slot, *el;
++ struct exception *e;
++
++ slot = &et->table[exception_hash(et, chunk)];
++ list_for_each(el, slot) {
++ e = list_entry(el, struct exception, hash_list);
++ if (e->old_chunk == chunk)
++ return e;
++ }
++
++ return NULL;
++}
++
++static inline struct exception *alloc_exception(void)
++{
++ struct exception *e;
++
++ e = kmem_cache_alloc(exception_cache, GFP_NOIO);
++ if (!e)
++ e = kmem_cache_alloc(exception_cache, GFP_ATOMIC);
++
++ return e;
++}
++
++static inline void free_exception(struct exception *e)
++{
++ kmem_cache_free(exception_cache, e);
++}
++
++static inline struct pending_exception *alloc_pending_exception(void)
++{
++ return mempool_alloc(pending_pool, GFP_NOIO);
++}
++
++static inline void free_pending_exception(struct pending_exception *pe)
++{
++ mempool_free(pe, pending_pool);
++}
++
++int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new)
++{
++ struct exception *e;
++
++ e = alloc_exception();
++ if (!e)
++ return -ENOMEM;
++
++ e->old_chunk = old;
++ e->new_chunk = new;
++ insert_exception(&s->complete, e);
++ return 0;
++}
++
++/*
++ * Hard coded magic.
++ */
++static int calc_max_buckets(void)
++{
++ unsigned long mem;
++
++ mem = num_physpages << PAGE_SHIFT;
++ mem /= 50;
++ mem /= sizeof(struct list_head);
++
++ return mem;
++}
++
++/*
++ * Rounds a number down to a power of 2.
++ */
++static inline uint32_t round_down(uint32_t n)
++{
++ while (n & (n - 1))
++ n &= (n - 1);
++ return n;
++}
++
++/*
++ * Allocate room for a suitable hash table.
++ */
++static int init_hash_tables(struct dm_snapshot *s)
++{
++ offset_t hash_size, cow_dev_size, origin_dev_size, max_buckets;
++
++ /*
++ * Calculate based on the size of the original volume or
++ * the COW volume...
++ */
++ cow_dev_size = get_dev_size(s->cow->dev);
++ origin_dev_size = get_dev_size(s->origin->dev);
++ max_buckets = calc_max_buckets();
++
++ hash_size = min(origin_dev_size, cow_dev_size) / s->chunk_size;
++ hash_size = min(hash_size, max_buckets);
++
++ /* Round it down to a power of 2 */
++ hash_size = round_down(hash_size);
++ if (init_exception_table(&s->complete, hash_size))
++ return -ENOMEM;
++
++ /*
++ * Allocate hash table for in-flight exceptions
++ * Make this smaller than the real hash table
++ */
++ hash_size >>= 3;
++ if (!hash_size)
++ hash_size = 64;
++
++ if (init_exception_table(&s->pending, hash_size)) {
++ exit_exception_table(&s->complete, exception_cache);
++ return -ENOMEM;
++ }
++
++ return 0;
++}
++
++/*
++ * Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n>
++ * <chunk-size>
++ */
++static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **argv, void **context)
++{
++ struct dm_snapshot *s;
++ unsigned long chunk_size;
++ unsigned long extent_size = 0L;
++ int r = -EINVAL;
++ char *persistent;
++ char *origin_path;
++ char *cow_path;
++ char *value;
++ int blocksize;
++
++ if (argc < 4) {
++ *context = "dm-snapshot: Not enough arguments";
++ r = -EINVAL;
++ goto bad;
++ }
++
++ origin_path = argv[0];
++ cow_path = argv[1];
++ persistent = argv[2];
++
++ if ((*persistent & 0x5f) != 'P' && (*persistent & 0x5f) != 'N') {
++ *context = "Persistent flag is not P or N";
++ r = -EINVAL;
++ goto bad;
++ }
++
++ chunk_size = simple_strtoul(argv[3], &value, 10);
++ if (chunk_size == 0 || value == NULL) {
++ *context = "Invalid chunk size";
++ r = -EINVAL;
++ goto bad;
++ }
++
++ /* Get the extent size for persistent snapshots */
++ if ((*persistent & 0x5f) == 'P') {
++ if (argc < 5) {
++ *context = "No extent size specified";
++ r = -EINVAL;
++ goto bad;
++ }
++
++ extent_size = simple_strtoul(argv[4], &value, 10);
++ if (extent_size == 0 || value == NULL) {
++ *context = "Invalid extent size";
++ r = -EINVAL;
++ goto bad;
++ }
++ }
++
++ s = kmalloc(sizeof(*s), GFP_KERNEL);
++ if (s == NULL) {
++ *context = "Cannot allocate snapshot context private structure";
++ r = -ENOMEM;
++ goto bad;
++ }
++
++ r = dm_table_get_device(t, origin_path, 0, 0, &s->origin);
++ if (r) {
++ *context = "Cannot get origin device";
++ goto bad_free;
++ }
++
++ r = dm_table_get_device(t, cow_path, 0, 0, &s->cow);
++ if (r) {
++ dm_table_put_device(t, s->origin);
++ *context = "Cannot get COW device";
++ goto bad_free;
++ }
++
++ /* Validate the extent and chunk sizes against the device block size */
++ blocksize = get_hardsect_size(s->cow->dev);
++ if (chunk_size % (blocksize / SECTOR_SIZE)) {
++ *context = "Chunk size is not a multiple of device blocksize";
++ r = -EINVAL;
++ goto bad_putdev;
++ }
++
++ if (extent_size % (blocksize / SECTOR_SIZE)) {
++ *context = "Extent size is not a multiple of device blocksize";
++ r = -EINVAL;
++ goto bad_putdev;
++ }
++
++ /* Check the sizes are small enough to fit in one kiovec */
++ if (chunk_size > KIO_MAX_SECTORS) {
++ *context = "Chunk size is too big";
++ r = -EINVAL;
++ goto bad_putdev;
++ }
++
++ if (extent_size > KIO_MAX_SECTORS) {
++ *context = "Extent size is too big";
++ r = -EINVAL;
++ goto bad_putdev;
++ }
++
++ /* Check chunk_size is a power of 2 */
++ if (chunk_size & (chunk_size - 1)) {
++ *context = "Chunk size is not a power of 2";
++ r = -EINVAL;
++ goto bad_putdev;
++ }
++
++ s->chunk_size = chunk_size;
++ s->chunk_mask = chunk_size - 1;
++ s->type = *persistent;
++ for (s->chunk_shift = 0; chunk_size;
++ s->chunk_shift++, chunk_size >>= 1)
++ ;
++ s->chunk_shift--;
++
++ s->valid = 1;
++ s->last_percent = 0;
++ s->table = t;
++ init_rwsem(&s->lock);
++
++ /* Allocate hash table for COW data */
++ if (init_hash_tables(s)) {
++ *context = "Unable to allocate hash table space";
++ r = -ENOMEM;
++ goto bad_putdev;
++ }
++
++ /*
++ * Check the persistent flag - done here because we need the iobuf
++ * to check the LV header
++ */
++ s->store.snap = s;
++
++ if ((*persistent & 0x5f) == 'P')
++ r = dm_create_persistent(&s->store, s->chunk_size);
++ else
++ r = dm_create_transient(&s->store, s, blocksize, context);
++
++ if (r) {
++ *context = "Couldn't create exception store";
++ r = -EINVAL;
++ goto bad_free1;
++ }
++
++ /* Flush IO to the origin device */
++#if LVM_VFS_ENHANCEMENT
++ fsync_dev_lockfs(s->origin->dev);
++#else
++ fsync_dev(s->origin->dev);
++#endif
++
++ /* Add snapshot to the list of snapshots for this origin */
++ if (register_snapshot(s)) {
++ r = -EINVAL;
++ *context = "Cannot register snapshot origin";
++ goto bad_free2;
++ }
++#if LVM_VFS_ENHANCEMENT
++ unlockfs(s->origin->dev);
++#endif
++ kcopyd_inc_client_count();
++
++ *context = s;
++ return 0;
++
++ bad_free2:
++ s->store.destroy(&s->store);
++
++ bad_free1:
++ exit_exception_table(&s->pending, pending_cache);
++ exit_exception_table(&s->complete, exception_cache);
++
++ bad_putdev:
++ dm_table_put_device(t, s->cow);
++ dm_table_put_device(t, s->origin);
++
++ bad_free:
++ kfree(s);
++
++ bad:
++ return r;
++}
++
++static void snapshot_dtr(struct dm_table *t, void *context)
++{
++ struct dm_snapshot *s = (struct dm_snapshot *) context;
++
++ dm_table_event(s->table);
++
++ unregister_snapshot(s);
++
++ exit_exception_table(&s->pending, pending_cache);
++ exit_exception_table(&s->complete, exception_cache);
++
++ /* Deallocate memory used */
++ s->store.destroy(&s->store);
++
++ dm_table_put_device(t, s->origin);
++ dm_table_put_device(t, s->cow);
++ kfree(s);
++
++ kcopyd_dec_client_count();
++}
++
++/*
++ * We hold lists of buffer_heads, using the b_reqnext field.
++ */
++static void queue_buffer(struct buffer_head **queue, struct buffer_head *bh)
++{
++ bh->b_reqnext = *queue;
++ *queue = bh;
++}
++
++/*
++ * Flush a list of buffers.
++ */
++static void flush_buffers(struct buffer_head *bh)
++{
++ struct buffer_head *n;
++
++ DMDEBUG("begin flush");
++ while (bh) {
++ n = bh->b_reqnext;
++ bh->b_reqnext = NULL;
++ DMDEBUG("flushing %p", bh);
++ generic_make_request(WRITE, bh);
++ bh = n;
++ }
++
++ run_task_queue(&tq_disk);
++}
++
++/*
++ * Error a list of buffers.
++ */
++static void error_buffers(struct buffer_head *bh)
++{
++ struct buffer_head *n;
++
++ while (bh) {
++ n = bh->b_reqnext;
++ bh->b_reqnext = NULL;
++ buffer_IO_error(bh);
++ bh = n;
++ }
++}
++
++static void pending_complete(struct pending_exception *pe, int success)
++{
++ struct exception *e;
++ struct dm_snapshot *s = pe->snap;
++
++ if (success) {
++ e = alloc_exception();
++ if (!e) {
++ printk("Unable to allocate exception.");
++ down_write(&s->lock);
++ s->store.drop_snapshot(&s->store);
++ s->valid = 0;
++ up_write(&s->lock);
++ return;
++ }
++
++ /*
++ * Add a proper exception, and remove the
++ * inflight exception from the list.
++ */
++ down_write(&s->lock);
++
++ memcpy(e, &pe->e, sizeof(*e));
++ insert_exception(&s->complete, e);
++ remove_exception(&pe->e);
++
++ /* Submit any pending write BHs */
++ up_write(&s->lock);
++
++ flush_buffers(pe->snapshot_bhs);
++ DMDEBUG("Exception completed successfully.");
++
++ /* Notify any interested parties */
++ if (s->store.percent_full) {
++ int pc = s->store.percent_full(&s->store);
++
++ if (pc >= s->last_percent + WAKE_UP_PERCENT) {
++ dm_table_event(s->table);
++ s->last_percent = pc - pc % WAKE_UP_PERCENT;
++ }
++ }
++
++ } else {
++ /* Read/write error - snapshot is unusable */
++ DMERR("Error reading/writing snapshot");
++
++ down_write(&s->lock);
++ s->store.drop_snapshot(&s->store);
++ s->valid = 0;
++ remove_exception(&pe->e);
++ up_write(&s->lock);
++
++ error_buffers(pe->snapshot_bhs);
++
++ dm_table_event(s->table);
++ DMDEBUG("Exception failed.");
++ }
++
++ if (list_empty(&pe->siblings))
++ flush_buffers(pe->origin_bhs);
++ else
++ list_del(&pe->siblings);
++
++ free_pending_exception(pe);
++}
++
++static void commit_callback(void *context, int success)
++{
++ struct pending_exception *pe = (struct pending_exception *) context;
++ pending_complete(pe, success);
++}
++
++/*
++ * Called when the copy I/O has finished. kcopyd actually runs
++ * this code so don't block.
++ */
++static void copy_callback(int err, void *context)
++{
++ struct pending_exception *pe = (struct pending_exception *) context;
++ struct dm_snapshot *s = pe->snap;
++
++ if (err)
++ pending_complete(pe, 0);
++
++ else
++ /* Update the metadata if we are persistent */
++ s->store.commit_exception(&s->store, &pe->e, commit_callback,
++ pe);
++}
++
++/*
++ * Dispatches the copy operation to kcopyd.
++ */
++static inline void start_copy(struct pending_exception *pe)
++{
++ struct dm_snapshot *s = pe->snap;
++ struct kcopyd_region src, dest;
++
++ src.dev = s->origin->dev;
++ src.sector = chunk_to_sector(s, pe->e.old_chunk);
++ src.count = s->chunk_size;
++
++ dest.dev = s->cow->dev;
++ dest.sector = chunk_to_sector(s, pe->e.new_chunk);
++ dest.count = s->chunk_size;
++
++ if (!pe->started) {
++ /* Hand over to kcopyd */
++ kcopyd_copy(&src, &dest, copy_callback, pe);
++ pe->started = 1;
++ }
++}
++
++/*
++ * Looks to see if this snapshot already has a pending exception
++ * for this chunk, otherwise it allocates a new one and inserts
++ * it into the pending table.
++ */
++static struct pending_exception *find_pending_exception(struct dm_snapshot *s,
++ struct buffer_head *bh)
++{
++ struct exception *e;
++ struct pending_exception *pe;
++ chunk_t chunk = sector_to_chunk(s, bh->b_rsector);
++
++ /*
++ * Is there a pending exception for this already ?
++ */
++ e = lookup_exception(&s->pending, chunk);
++ if (e) {
++ /* cast the exception to a pending exception */
++ pe = list_entry(e, struct pending_exception, e);
++
++ } else {
++ /* Create a new pending exception */
++ pe = alloc_pending_exception();
++ if (!pe) {
++ DMWARN("Couldn't allocate pending exception.");
++ return NULL;
++ }
++
++ pe->e.old_chunk = chunk;
++ pe->origin_bhs = pe->snapshot_bhs = NULL;
++ INIT_LIST_HEAD(&pe->siblings);
++ pe->snap = s;
++ pe->started = 0;
++
++ if (s->store.prepare_exception(&s->store, &pe->e)) {
++ free_pending_exception(pe);
++ s->valid = 0;
++ return NULL;
++ }
++
++ insert_exception(&s->pending, &pe->e);
++ }
++
++ return pe;
++}
++
++static inline void remap_exception(struct dm_snapshot *s, struct exception *e,
++ struct buffer_head *bh)
++{
++ bh->b_rdev = s->cow->dev;
++ bh->b_rsector = chunk_to_sector(s, e->new_chunk) +
++ (bh->b_rsector & s->chunk_mask);
++}
++
++static int snapshot_map(struct buffer_head *bh, int rw, void *context)
++{
++ struct exception *e;
++ struct dm_snapshot *s = (struct dm_snapshot *) context;
++ int r = 1;
++ chunk_t chunk;
++ struct pending_exception *pe;
++
++ chunk = sector_to_chunk(s, bh->b_rsector);
++
++ /* Full snapshots are not usable */
++ if (!s->valid)
++ return -1;
++
++ /*
++ * Write to snapshot - higher level takes care of RW/RO
++ * flags so we should only get this if we are
++ * writeable.
++ */
++ if (rw == WRITE) {
++
++ down_write(&s->lock);
++
++ /* If the block is already remapped - use that, else remap it */
++ e = lookup_exception(&s->complete, chunk);
++ if (e)
++ remap_exception(s, e, bh);
++
++ else {
++ pe = find_pending_exception(s, bh);
++
++ if (!pe) {
++ s->store.drop_snapshot(&s->store);
++ s->valid = 0;
++ }
++
++ queue_buffer(&pe->snapshot_bhs, bh);
++ start_copy(pe);
++ r = 0;
++ }
++
++ up_write(&s->lock);
++
++ } else {
++ /*
++ * FIXME: this read path scares me because we
++ * always use the origin when we have a pending
++ * exception. However I can't think of a
++ * situation where this is wrong - ejt.
++ */
++
++ /* Do reads */
++ down_read(&s->lock);
++
++ /* See if it it has been remapped */
++ e = lookup_exception(&s->complete, chunk);
++ if (e)
++ remap_exception(s, e, bh);
++ else
++ bh->b_rdev = s->origin->dev;
++
++ up_read(&s->lock);
++ }
++
++ return r;
++}
++
++static void list_merge(struct list_head *l1, struct list_head *l2)
++{
++ struct list_head *l1_n, *l2_p;
++
++ l1_n = l1->next;
++ l2_p = l2->prev;
++
++ l1->next = l2;
++ l2->prev = l1;
++
++ l2_p->next = l1_n;
++ l1_n->prev = l2_p;
++}
++
++static int __origin_write(struct list_head *snapshots, struct buffer_head *bh)
++{
++ int r = 1;
++ struct list_head *sl;
++ struct dm_snapshot *snap;
++ struct exception *e;
++ struct pending_exception *pe, *last = NULL;
++ chunk_t chunk;
++
++ /* Do all the snapshots on this origin */
++ list_for_each(sl, snapshots) {
++ snap = list_entry(sl, struct dm_snapshot, list);
++
++ /* Only deal with valid snapshots */
++ if (!snap->valid)
++ continue;
++
++ down_write(&snap->lock);
++
++ /*
++ * Remember, different snapshots can have
++ * different chunk sizes.
++ */
++ chunk = sector_to_chunk(snap, bh->b_rsector);
++
++ /*
++ * Check exception table to see if block
++ * is already remapped in this snapshot
++ * and trigger an exception if not.
++ */
++ e = lookup_exception(&snap->complete, chunk);
++ if (!e) {
++ pe = find_pending_exception(snap, bh);
++ if (!pe) {
++ snap->store.drop_snapshot(&snap->store);
++ snap->valid = 0;
++
++ } else {
++ if (last)
++ list_merge(&pe->siblings,
++ &last->siblings);
++
++ last = pe;
++ r = 0;
++ }
++ }
++
++ up_write(&snap->lock);
++ }
++
++ /*
++ * Now that we have a complete pe list we can start the copying.
++ */
++ if (last) {
++ pe = last;
++ do {
++ down_write(&pe->snap->lock);
++ queue_buffer(&pe->origin_bhs, bh);
++ start_copy(pe);
++ up_write(&pe->snap->lock);
++ pe = list_entry(pe->siblings.next,
++ struct pending_exception, siblings);
++
++ } while (pe != last);
++ }
++
++ return r;
++}
++
++static int snapshot_status(status_type_t type, char *result,
++ int maxlen, void *context)
++{
++ struct dm_snapshot *snap = (struct dm_snapshot *) context;
++ char cow[16];
++ char org[16];
++
++ switch (type) {
++ case STATUSTYPE_INFO:
++ if (!snap->valid)
++ snprintf(result, maxlen, "Invalid");
++ else {
++ if (snap->store.percent_full)
++ snprintf(result, maxlen, "%d%%",
++ snap->store.percent_full(&snap->
++ store));
++ else
++ snprintf(result, maxlen, "Unknown");
++ }
++ break;
++
++ case STATUSTYPE_TABLE:
++ /*
++ * kdevname returns a static pointer so we need
++ * to make private copies if the output is to
++ * make sense.
++ */
++ strncpy(cow, kdevname(snap->cow->dev), sizeof(cow));
++ strncpy(org, kdevname(snap->origin->dev), sizeof(org));
++ snprintf(result, maxlen, "%s %s %c %ld", org, cow,
++ snap->type, snap->chunk_size);
++ break;
++ }
++
++ return 0;
++}
++
++/*
++ * Called on a write from the origin driver.
++ */
++int do_origin(struct dm_dev *origin, struct buffer_head *bh)
++{
++ struct origin *o;
++ int r;
++
++ down_read(&_origins_lock);
++ o = __lookup_origin(origin->dev);
++ if (!o)
++ BUG();
++
++ r = __origin_write(&o->snapshots, bh);
++ up_read(&_origins_lock);
++
++ return r;
++}
++
++/*
++ * Origin: maps a linear range of a device, with hooks for snapshotting.
++ */
++
++/*
++ * Construct an origin mapping: <dev_path>
++ * The context for an origin is merely a 'struct dm_dev *'
++ * pointing to the real device.
++ */
++static int origin_ctr(struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **argv, void **context)
++{
++ int r;
++ struct dm_dev *dev;
++
++ if (argc != 1) {
++ *context = "dm-origin: incorrect number of arguments";
++ return -EINVAL;
++ }
++
++ r = dm_table_get_device(t, argv[0], 0, l, &dev);
++ if (r) {
++ *context = "Cannot get target device";
++ return r;
++ }
++
++ *context = dev;
++
++ return 0;
++}
++
++static void origin_dtr(struct dm_table *t, void *c)
++{
++ struct dm_dev *dev = (struct dm_dev *) c;
++ dm_table_put_device(t, dev);
++}
++
++static int origin_map(struct buffer_head *bh, int rw, void *context)
++{
++ struct dm_dev *dev = (struct dm_dev *) context;
++ bh->b_rdev = dev->dev;
++
++ /* Only tell snapshots if this is a write */
++ return (rw == WRITE) ? do_origin(dev, bh) : 1;
++}
++
++static int origin_status(status_type_t type, char *result,
++ int maxlen, void *context)
++{
++ struct dm_dev *dev = (struct dm_dev *) context;
++
++ switch (type) {
++ case STATUSTYPE_INFO:
++ result[0] = '\0';
++ break;
++
++ case STATUSTYPE_TABLE:
++ snprintf(result, maxlen, "%s", kdevname(dev->dev));
++ break;
++ }
++
++ return 0;
++}
++
++static struct target_type origin_target = {
++ name: "snapshot-origin",
++ module: THIS_MODULE,
++ ctr: origin_ctr,
++ dtr: origin_dtr,
++ map: origin_map,
++ status: origin_status,
++ err: NULL
++};
++
++static struct target_type snapshot_target = {
++ name: "snapshot",
++ module: THIS_MODULE,
++ ctr: snapshot_ctr,
++ dtr: snapshot_dtr,
++ map: snapshot_map,
++ status: snapshot_status,
++ err: NULL
++};
++
++int __init dm_snapshot_init(void)
++{
++ int r;
++
++ r = dm_register_target(&snapshot_target);
++ if (r) {
++ DMERR("snapshot target register failed %d", r);
++ return r;
++ }
++
++ r = dm_register_target(&origin_target);
++ if (r < 0) {
++ DMERR("Device mapper: Origin: register failed %d\n", r);
++ goto bad1;
++ }
++
++ r = init_origin_hash();
++ if (r) {
++ DMERR("init_origin_hash failed.");
++ goto bad2;
++ }
++
++ exception_cache = kmem_cache_create("dm-snapshot-ex",
++ sizeof(struct exception),
++ __alignof__(struct exception),
++ 0, NULL, NULL);
++ if (!exception_cache) {
++ DMERR("Couldn't create exception cache.");
++ r = -ENOMEM;
++ goto bad3;
++ }
++
++ pending_cache =
++ kmem_cache_create("dm-snapshot-in",
++ sizeof(struct pending_exception),
++ __alignof__(struct pending_exception),
++ 0, NULL, NULL);
++ if (!pending_cache) {
++ DMERR("Couldn't create pending cache.");
++ r = -ENOMEM;
++ goto bad4;
++ }
++
++ pending_pool = mempool_create(128, mempool_alloc_slab,
++ mempool_free_slab, pending_cache);
++ if (!pending_pool) {
++ DMERR("Couldn't create pending pool.");
++ r = -ENOMEM;
++ goto bad5;
++ }
++
++ return 0;
++
++ bad5:
++ kmem_cache_destroy(pending_cache);
++ bad4:
++ kmem_cache_destroy(exception_cache);
++ bad3:
++ exit_origin_hash();
++ bad2:
++ dm_unregister_target(&origin_target);
++ bad1:
++ dm_unregister_target(&snapshot_target);
++ return r;
++}
++
++void dm_snapshot_exit(void)
++{
++ int r;
++
++ r = dm_unregister_target(&snapshot_target);
++ if (r)
++ DMERR("snapshot unregister failed %d", r);
++
++ r = dm_unregister_target(&origin_target);
++ if (r)
++ DMERR("origin unregister failed %d", r);
++
++ exit_origin_hash();
++ mempool_destroy(pending_pool);
++ kmem_cache_destroy(pending_cache);
++ kmem_cache_destroy(exception_cache);
++}
++
++/*
++ * Overrides for Emacs so that we follow Linus's tabbing style.
++ * Emacs will notice this stuff at the end of the file and automatically
++ * adjust the settings for this buffer only. This must remain at the end
++ * of the file.
++ * ---------------------------------------------------------------------------
++ * Local variables:
++ * c-file-style: "linux"
++ * End:
++ */
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-snapshot.h linux/drivers/md/dm-snapshot.h
+--- linux-2.4.19-rc1/drivers/md/dm-snapshot.h Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-snapshot.h Tue Jun 25 22:39:48 2002
+@@ -0,0 +1,147 @@
++/*
++ * dm-snapshot.c
++ *
++ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#ifndef DM_SNAPSHOT_H
++#define DM_SNAPSHOT_H
++
++#include "dm.h"
++#include <linux/blkdev.h>
++
++struct exception_table {
++ uint32_t hash_mask;
++ struct list_head *table;
++};
++
++/*
++ * The snapshot code deals with largish chunks of the disk at a
++ * time. Typically 64k - 256k.
++ */
++/* FIXME: can we get away with limiting these to a uint32_t ? */
++typedef offset_t chunk_t;
++
++/*
++ * An exception is used where an old chunk of data has been
++ * replaced by a new one.
++ */
++struct exception {
++ struct list_head hash_list;
++
++ chunk_t old_chunk;
++ chunk_t new_chunk;
++};
++
++/*
++ * Abstraction to handle the meta/layout of exception stores (the
++ * COW device).
++ */
++struct exception_store {
++
++ /*
++ * Destroys this object when you've finished with it.
++ */
++ void (*destroy) (struct exception_store *store);
++
++ /*
++ * Find somewhere to store the next exception.
++ */
++ int (*prepare_exception) (struct exception_store *store,
++ struct exception *e);
++
++ /*
++ * Update the metadata with this exception.
++ */
++ void (*commit_exception) (struct exception_store *store,
++ struct exception *e,
++ void (*callback) (void *, int success),
++ void *callback_context);
++
++ /*
++ * The snapshot is invalid, note this in the metadata.
++ */
++ void (*drop_snapshot) (struct exception_store *store);
++
++ /*
++ * Return the %age full of the snapshot
++ */
++ int (*percent_full) (struct exception_store *store);
++
++ struct dm_snapshot *snap;
++ void *context;
++};
++
++struct dm_snapshot {
++ struct rw_semaphore lock;
++ struct dm_table *table;
++
++ struct dm_dev *origin;
++ struct dm_dev *cow;
++
++ /* List of snapshots per Origin */
++ struct list_head list;
++
++ /* Size of data blocks saved - must be a power of 2 */
++ chunk_t chunk_size;
++ chunk_t chunk_mask;
++ chunk_t chunk_shift;
++
++ /* You can't use a snapshot if this is 0 (e.g. if full) */
++ int valid;
++
++ /* Used for display of table */
++ char type;
++
++ /* The last percentage we notified */
++ int last_percent;
++
++ struct exception_table pending;
++ struct exception_table complete;
++
++ /* The on disk metadata handler */
++ struct exception_store store;
++};
++
++/*
++ * Used by the exception stores to load exceptions hen
++ * initialising.
++ */
++int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new);
++
++/*
++ * Constructor and destructor for the default persistent
++ * store.
++ */
++int dm_create_persistent(struct exception_store *store, uint32_t chunk_size);
++
++int dm_create_transient(struct exception_store *store,
++ struct dm_snapshot *s, int blocksize, void **error);
++
++/*
++ * Return the number of sectors in the device.
++ */
++static inline offset_t get_dev_size(kdev_t dev)
++{
++ int *sizes;
++
++ sizes = blk_size[MAJOR(dev)];
++ if (sizes)
++ return sizes[MINOR(dev)] << 1;
++
++ return 0;
++}
++
++static inline chunk_t sector_to_chunk(struct dm_snapshot *s, offset_t sector)
++{
++ return (sector & ~s->chunk_mask) >> s->chunk_shift;
++}
++
++static inline offset_t chunk_to_sector(struct dm_snapshot *s, chunk_t chunk)
++{
++ return chunk << s->chunk_shift;
++}
++
++#endif
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.c linux/drivers/md/dm.c
+--- linux-2.4.19-rc1/drivers/md/dm.c Tue Jun 25 22:30:30 2002
++++ linux/drivers/md/dm.c Tue Jun 25 22:31:54 2002
+@@ -5,6 +5,7 @@
+ */
+
+ #include "dm.h"
++#include "kcopyd.h"
+
+ #include <linux/blk.h>
+ #include <linux/blkpg.h>
+@@ -268,6 +269,7 @@
+ xx(dm_target)
+ xx(dm_linear)
+ xx(dm_stripe)
++ xx(dm_snapshot)
+ xx(dm_interface)
+ #undef xx
+ };
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.h linux/drivers/md/dm.h
+--- linux-2.4.19-rc1/drivers/md/dm.h Tue Jun 25 22:46:34 2002
++++ linux/drivers/md/dm.h Tue Jun 25 22:39:45 2002
+@@ -179,6 +179,10 @@
+ */
+ void dm_table_event(struct dm_table *t);
+
++/* Snapshots */
++int dm_snapshot_init(void);
++void dm_snapshot_exit(void);
++
+ #define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
+ #define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x)
+ #define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x)
+diff -ruN linux-2.4.19-rc1/drivers/md/kcopyd.c linux/drivers/md/kcopyd.c
+--- linux-2.4.19-rc1/drivers/md/kcopyd.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/kcopyd.c Tue Jun 25 22:31:08 2002
+@@ -0,0 +1,832 @@
++/*
++ * Copyright (C) 2002 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include <linux/config.h>
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/slab.h>
++#include <linux/list.h>
++#include <linux/fs.h>
++#include <linux/blkdev.h>
++#include <linux/device-mapper.h>
++#include <linux/mempool.h>
++#include <asm/atomic.h>
++#include <linux/pagemap.h>
++#include <linux/locks.h>
++
++#include "kcopyd.h"
++
++/* FIXME: this is only needed for the DMERR macros */
++#include "dm.h"
++
++/*
++ * Hard sector size used all over the kernel.
++ */
++#define SECTOR_SIZE 512
++#define SECTOR_SHIFT 9
++
++static void wake_kcopyd(void);
++
++/*-----------------------------------------------------------------
++ * We reserve our own pool of preallocated pages that are
++ * only used for kcopyd io.
++ *---------------------------------------------------------------*/
++
++/*
++ * FIXME: This should be configurable.
++ */
++#define NUM_PAGES 512
++
++static DECLARE_MUTEX(_pages_lock);
++static int _num_free_pages;
++static struct page *_pages_array[NUM_PAGES];
++static DECLARE_MUTEX(start_lock);
++
++static int init_pages(void)
++{
++ int i;
++ struct page *p;
++
++ for (i = 0; i < NUM_PAGES; i++) {
++ p = alloc_page(GFP_KERNEL);
++ if (!p)
++ goto bad;
++
++ LockPage(p);
++ _pages_array[i] = p;
++ }
++
++ _num_free_pages = NUM_PAGES;
++ return 0;
++
++ bad:
++ while (i--)
++ __free_page(_pages_array[i]);
++ return -ENOMEM;
++}
++
++static void exit_pages(void)
++{
++ int i;
++ struct page *p;
++
++ for (i = 0; i < NUM_PAGES; i++) {
++ p = _pages_array[i];
++ UnlockPage(p);
++ __free_page(p);
++ }
++
++ _num_free_pages = 0;
++}
++
++static int kcopyd_get_pages(int num, struct page **result)
++{
++ int i;
++
++ down(&_pages_lock);
++ if (_num_free_pages < num) {
++ up(&_pages_lock);
++ return -ENOMEM;
++ }
++
++ for (i = 0; i < num; i++) {
++ _num_free_pages--;
++ result[i] = _pages_array[_num_free_pages];
++ }
++ up(&_pages_lock);
++
++ return 0;
++}
++
++static void kcopyd_free_pages(int num, struct page **result)
++{
++ int i;
++
++ down(&_pages_lock);
++ for (i = 0; i < num; i++)
++ _pages_array[_num_free_pages++] = result[i];
++ up(&_pages_lock);
++}
++
++/*-----------------------------------------------------------------
++ * We keep our own private pool of buffer_heads. These are just
++ * held in a list on the b_reqnext field.
++ *---------------------------------------------------------------*/
++
++/*
++ * Make sure we have enough buffers to always keep the pages
++ * occupied. So we assume the worst case scenario where blocks
++ * are the size of a single sector.
++ */
++#define NUM_BUFFERS NUM_PAGES * (PAGE_SIZE / SECTOR_SIZE)
++
++static spinlock_t _buffer_lock = SPIN_LOCK_UNLOCKED;
++static struct buffer_head *_all_buffers;
++static struct buffer_head *_free_buffers;
++
++static int init_buffers(void)
++{
++ int i;
++ struct buffer_head *buffers;
++
++ buffers = vcalloc(NUM_BUFFERS, sizeof(struct buffer_head));
++ if (!buffers) {
++ DMWARN("Couldn't allocate buffer heads.");
++ return -ENOMEM;
++ }
++
++ for (i = 0; i < NUM_BUFFERS; i++) {
++ if (i < NUM_BUFFERS - 1)
++ buffers[i].b_reqnext = &buffers[i + 1];
++ init_waitqueue_head(&buffers[i].b_wait);
++ INIT_LIST_HEAD(&buffers[i].b_inode_buffers);
++ }
++
++ _all_buffers = _free_buffers = buffers;
++ return 0;
++}
++
++static void exit_buffers(void)
++{
++ vfree(_all_buffers);
++}
++
++static struct buffer_head *alloc_buffer(void)
++{
++ struct buffer_head *r;
++ int flags;
++
++ spin_lock_irqsave(&_buffer_lock, flags);
++
++ if (!_free_buffers)
++ r = NULL;
++ else {
++ r = _free_buffers;
++ _free_buffers = _free_buffers->b_reqnext;
++ r->b_reqnext = NULL;
++ }
++
++ spin_unlock_irqrestore(&_buffer_lock, flags);
++
++ return r;
++}
++
++/*
++ * Only called from interrupt context.
++ */
++static void free_buffer(struct buffer_head *bh)
++{
++ int flags;
++
++ spin_lock_irqsave(&_buffer_lock, flags);
++ bh->b_reqnext = _free_buffers;
++ _free_buffers = bh;
++ spin_unlock_irqrestore(&_buffer_lock, flags);
++}
++
++/*-----------------------------------------------------------------
++ * kcopyd_jobs need to be allocated by the *clients* of kcopyd,
++ * for this reason we use a mempool to prevent the client from
++ * ever having to do io (which could cause a
++ * deadlock).
++ *---------------------------------------------------------------*/
++#define MIN_JOBS NUM_PAGES
++
++static kmem_cache_t *_job_cache = NULL;
++static mempool_t *_job_pool = NULL;
++
++/*
++ * We maintain three lists of jobs:
++ *
++ * i) jobs waiting for pages
++ * ii) jobs that have pages, and are waiting for the io to be issued.
++ * iii) jobs that have completed.
++ *
++ * All three of these are protected by job_lock.
++ */
++
++static spinlock_t _job_lock = SPIN_LOCK_UNLOCKED;
++
++static LIST_HEAD(_complete_jobs);
++static LIST_HEAD(_io_jobs);
++static LIST_HEAD(_pages_jobs);
++
++static int init_jobs(void)
++{
++ INIT_LIST_HEAD(&_complete_jobs);
++ INIT_LIST_HEAD(&_io_jobs);
++ INIT_LIST_HEAD(&_pages_jobs);
++
++ _job_cache = kmem_cache_create("kcopyd-jobs", sizeof(struct kcopyd_job),
++ __alignof__(struct kcopyd_job),
++ 0, NULL, NULL);
++ if (!_job_cache)
++ return -ENOMEM;
++
++ _job_pool = mempool_create(MIN_JOBS, mempool_alloc_slab,
++ mempool_free_slab, _job_cache);
++ if (!_job_pool) {
++ kmem_cache_destroy(_job_cache);
++ return -ENOMEM;
++ }
++
++ return 0;
++}
++
++static void exit_jobs(void)
++{
++ mempool_destroy(_job_pool);
++ kmem_cache_destroy(_job_cache);
++}
++
++struct kcopyd_job *kcopyd_alloc_job(void)
++{
++ struct kcopyd_job *job;
++
++ job = mempool_alloc(_job_pool, GFP_KERNEL);
++ if (!job)
++ return NULL;
++
++ memset(job, 0, sizeof(*job));
++ return job;
++}
++
++void kcopyd_free_job(struct kcopyd_job *job)
++{
++ mempool_free(job, _job_pool);
++}
++
++/*
++ * Functions to push and pop a job onto the head of a given job
++ * list.
++ */
++static inline struct kcopyd_job *pop(struct list_head *jobs)
++{
++ struct kcopyd_job *job = NULL;
++ int flags;
++
++ spin_lock_irqsave(&_job_lock, flags);
++
++ if (!list_empty(jobs)) {
++ job = list_entry(jobs->next, struct kcopyd_job, list);
++ list_del(&job->list);
++ }
++ spin_unlock_irqrestore(&_job_lock, flags);
++
++ return job;
++}
++
++static inline void push(struct list_head *jobs, struct kcopyd_job *job)
++{
++ int flags;
++
++ spin_lock_irqsave(&_job_lock, flags);
++ list_add(&job->list, jobs);
++ spin_unlock_irqrestore(&_job_lock, flags);
++}
++
++/*
++ * Completion function for one of our buffers.
++ */
++static void end_bh(struct buffer_head *bh, int uptodate)
++{
++ struct kcopyd_job *job = bh->b_private;
++
++ mark_buffer_uptodate(bh, uptodate);
++ unlock_buffer(bh);
++
++ if (!uptodate)
++ job->err = -EIO;
++
++ /* are we the last ? */
++ if (atomic_dec_and_test(&job->nr_incomplete)) {
++ push(&_complete_jobs, job);
++ wake_kcopyd();
++ }
++
++ free_buffer(bh);
++}
++
++static void dispatch_bh(struct kcopyd_job *job,
++ struct buffer_head *bh, int block)
++{
++ int p;
++
++ /*
++ * Add in the job offset
++ */
++ bh->b_blocknr = (job->disk.sector >> job->block_shift) + block;
++
++ p = block >> job->bpp_shift;
++ block &= job->bpp_mask;
++
++ bh->b_dev = B_FREE;
++ bh->b_size = job->block_size;
++ set_bh_page(bh, job->pages[p], ((block << job->block_shift) +
++ job->offset) << SECTOR_SHIFT);
++ bh->b_this_page = bh;
++
++ init_buffer(bh, end_bh, job);
++
++ bh->b_dev = job->disk.dev;
++ bh->b_state = ((1 << BH_Mapped) | (1 << BH_Lock) | (1 << BH_Req));
++
++ set_bit(BH_Uptodate, &bh->b_state);
++ if (job->rw == WRITE)
++ clear_bit(BH_Dirty, &bh->b_state);
++
++ submit_bh(job->rw, bh);
++}
++
++/*
++ * These three functions process 1 item from the corresponding
++ * job list.
++ *
++ * They return:
++ * < 0: error
++ * 0: success
++ * > 0: can't process yet.
++ */
++static int run_complete_job(struct kcopyd_job *job)
++{
++ job->callback(job);
++ return 0;
++}
++
++/*
++ * Request io on as many buffer heads as we can currently get for
++ * a particular job.
++ */
++static int run_io_job(struct kcopyd_job *job)
++{
++ unsigned int block;
++ struct buffer_head *bh;
++
++ for (block = atomic_read(&job->nr_requested);
++ block < job->nr_blocks; block++) {
++ bh = alloc_buffer();
++ if (!bh)
++ break;
++
++ atomic_inc(&job->nr_requested);
++ dispatch_bh(job, bh, block);
++ }
++
++ return (block == job->nr_blocks) ? 0 : 1;
++}
++
++static int run_pages_job(struct kcopyd_job *job)
++{
++ int r;
++
++ job->nr_pages = (job->disk.count + job->offset) /
++ (PAGE_SIZE / SECTOR_SIZE);
++ r = kcopyd_get_pages(job->nr_pages, job->pages);
++
++ if (!r) {
++ /* this job is ready for io */
++ push(&_io_jobs, job);
++ return 0;
++ }
++
++ if (r == -ENOMEM)
++ /* can complete now */
++ return 1;
++
++ return r;
++}
++
++/*
++ * Run through a list for as long as possible. Returns the count
++ * of successful jobs.
++ */
++static int process_jobs(struct list_head *jobs, int (*fn) (struct kcopyd_job *))
++{
++ struct kcopyd_job *job;
++ int r, count = 0;
++
++ while ((job = pop(jobs))) {
++
++ r = fn(job);
++
++ if (r < 0) {
++ /* error this rogue job */
++ job->err = r;
++ push(&_complete_jobs, job);
++ break;
++ }
++
++ if (r > 0) {
++ /*
++ * We couldn't service this job ATM, so
++ * push this job back onto the list.
++ */
++ push(jobs, job);
++ break;
++ }
++
++ count++;
++ }
++
++ return count;
++}
++
++/*
++ * kcopyd does this every time it's woken up.
++ */
++static void do_work(void)
++{
++ int count;
++
++ /*
++ * We loop round until there is no more work to do.
++ */
++ do {
++ count = process_jobs(&_complete_jobs, run_complete_job);
++ count += process_jobs(&_io_jobs, run_io_job);
++ count += process_jobs(&_pages_jobs, run_pages_job);
++
++ } while (count);
++
++ run_task_queue(&tq_disk);
++}
++
++/*-----------------------------------------------------------------
++ * The daemon
++ *---------------------------------------------------------------*/
++static atomic_t _kcopyd_must_die;
++static DECLARE_MUTEX(_run_lock);
++static DECLARE_WAIT_QUEUE_HEAD(_job_queue);
++
++static int kcopyd(void *arg)
++{
++ DECLARE_WAITQUEUE(wq, current);
++
++ daemonize();
++ strcpy(current->comm, "kcopyd");
++ atomic_set(&_kcopyd_must_die, 0);
++
++ add_wait_queue(&_job_queue, &wq);
++
++ down(&_run_lock);
++ up(&start_lock);
++
++ while (1) {
++ set_current_state(TASK_INTERRUPTIBLE);
++
++ if (atomic_read(&_kcopyd_must_die))
++ break;
++
++ do_work();
++ schedule();
++ }
++
++ set_current_state(TASK_RUNNING);
++ remove_wait_queue(&_job_queue, &wq);
++
++ up(&_run_lock);
++
++ return 0;
++}
++
++static int start_daemon(void)
++{
++ static pid_t pid = 0;
++
++ down(&start_lock);
++
++ pid = kernel_thread(kcopyd, NULL, 0);
++ if (pid <= 0) {
++ DMERR("Failed to start kcopyd thread");
++ return -EAGAIN;
++ }
++
++ /*
++ * wait for the daemon to up this mutex.
++ */
++ down(&start_lock);
++ up(&start_lock);
++
++ return 0;
++}
++
++static int stop_daemon(void)
++{
++ atomic_set(&_kcopyd_must_die, 1);
++ wake_kcopyd();
++ down(&_run_lock);
++ up(&_run_lock);
++
++ return 0;
++}
++
++static void wake_kcopyd(void)
++{
++ wake_up_interruptible(&_job_queue);
++}
++
++static int calc_shift(unsigned int n)
++{
++ int s;
++
++ for (s = 0; n; s++, n >>= 1)
++ ;
++
++ return --s;
++}
++
++static void calc_block_sizes(struct kcopyd_job *job)
++{
++ job->block_size = get_hardsect_size(job->disk.dev);
++ job->block_shift = calc_shift(job->block_size / SECTOR_SIZE);
++ job->bpp_shift = PAGE_SHIFT - job->block_shift - SECTOR_SHIFT;
++ job->bpp_mask = (1 << job->bpp_shift) - 1;
++ job->nr_blocks = job->disk.count >> job->block_shift;
++ atomic_set(&job->nr_requested, 0);
++ atomic_set(&job->nr_incomplete, job->nr_blocks);
++}
++
++int kcopyd_io(struct kcopyd_job *job)
++{
++ calc_block_sizes(job);
++ push(job->pages[0] ? &_io_jobs : &_pages_jobs, job);
++ wake_kcopyd();
++ return 0;
++}
++
++/*-----------------------------------------------------------------
++ * The copier is implemented on top of the simpler async io
++ * daemon above.
++ *---------------------------------------------------------------*/
++struct copy_info {
++ kcopyd_notify_fn notify;
++ void *notify_context;
++
++ struct kcopyd_region to;
++};
++
++#define MIN_INFOS 128
++static kmem_cache_t *_copy_cache = NULL;
++static mempool_t *_copy_pool = NULL;
++
++static int init_copier(void)
++{
++ _copy_cache = kmem_cache_create("kcopyd-info",
++ sizeof(struct copy_info),
++ __alignof__(struct copy_info),
++ 0, NULL, NULL);
++ if (!_copy_cache)
++ return -ENOMEM;
++
++ _copy_pool = mempool_create(MIN_INFOS, mempool_alloc_slab,
++ mempool_free_slab, _copy_cache);
++ if (!_copy_pool) {
++ kmem_cache_destroy(_copy_cache);
++ return -ENOMEM;
++ }
++
++ return 0;
++}
++
++static void exit_copier(void)
++{
++ if (_copy_pool)
++ mempool_destroy(_copy_pool);
++
++ if (_copy_cache)
++ kmem_cache_destroy(_copy_cache);
++}
++
++static inline struct copy_info *alloc_copy_info(void)
++{
++ return mempool_alloc(_copy_pool, GFP_KERNEL);
++}
++
++static inline void free_copy_info(struct copy_info *info)
++{
++ mempool_free(info, _copy_pool);
++}
++
++void copy_complete(struct kcopyd_job *job)
++{
++ struct copy_info *info = (struct copy_info *) job->context;
++
++ if (info->notify)
++ info->notify(job->err, info->notify_context);
++
++ free_copy_info(info);
++
++ kcopyd_free_pages(job->nr_pages, job->pages);
++
++ kcopyd_free_job(job);
++}
++
++static void page_write_complete(struct kcopyd_job *job)
++{
++ struct copy_info *info = (struct copy_info *) job->context;
++ int i;
++
++ if (info->notify)
++ info->notify(job->err, info->notify_context);
++
++ free_copy_info(info);
++ for (i = 0; i < job->nr_pages; i++)
++ put_page(job->pages[i]);
++
++ kcopyd_free_job(job);
++}
++
++/*
++ * These callback functions implement the state machine that copies regions.
++ */
++void copy_write(struct kcopyd_job *job)
++{
++ struct copy_info *info = (struct copy_info *) job->context;
++
++ if (job->err && info->notify) {
++ info->notify(job->err, job->context);
++ kcopyd_free_job(job);
++ free_copy_info(info);
++ return;
++ }
++
++ job->rw = WRITE;
++ memcpy(&job->disk, &info->to, sizeof(job->disk));
++ job->callback = copy_complete;
++ job->context = info;
++
++ /*
++ * Queue the write.
++ */
++ kcopyd_io(job);
++}
++
++int kcopyd_write_pages(struct kcopyd_region *to, int nr_pages,
++ struct page **pages, int offset, kcopyd_notify_fn fn,
++ void *context)
++{
++ struct copy_info *info;
++ struct kcopyd_job *job;
++ int i;
++
++ /*
++ * Allocate a new copy_info.
++ */
++ info = alloc_copy_info();
++ if (!info)
++ return -ENOMEM;
++
++ job = kcopyd_alloc_job();
++ if (!job) {
++ free_copy_info(info);
++ return -ENOMEM;
++ }
++
++ /*
++ * set up for the write.
++ */
++ info->notify = fn;
++ info->notify_context = context;
++ memcpy(&info->to, to, sizeof(*to));
++
++ /* Get the pages */
++ job->nr_pages = nr_pages;
++ for (i = 0; i < nr_pages; i++) {
++ get_page(pages[i]);
++ job->pages[i] = pages[i];
++ }
++
++ job->rw = WRITE;
++
++ memcpy(&job->disk, &info->to, sizeof(job->disk));
++ job->offset = offset;
++ calc_block_sizes(job);
++ job->callback = page_write_complete;
++ job->context = info;
++
++ /*
++ * Trigger job.
++ */
++ kcopyd_io(job);
++ return 0;
++}
++
++int kcopyd_copy(struct kcopyd_region *from, struct kcopyd_region *to,
++ kcopyd_notify_fn fn, void *context)
++{
++ struct copy_info *info;
++ struct kcopyd_job *job;
++
++ /*
++ * Allocate a new copy_info.
++ */
++ info = alloc_copy_info();
++ if (!info)
++ return -ENOMEM;
++
++ job = kcopyd_alloc_job();
++ if (!job) {
++ free_copy_info(info);
++ return -ENOMEM;
++ }
++
++ /*
++ * set up for the read.
++ */
++ info->notify = fn;
++ info->notify_context = context;
++ memcpy(&info->to, to, sizeof(*to));
++
++ job->rw = READ;
++ memcpy(&job->disk, from, sizeof(*from));
++
++ job->offset = 0;
++ calc_block_sizes(job);
++ job->callback = copy_write;
++ job->context = info;
++
++ /*
++ * Trigger job.
++ */
++ kcopyd_io(job);
++ return 0;
++}
++
++/*-----------------------------------------------------------------
++ * Unit setup
++ *---------------------------------------------------------------*/
++static struct {
++ int (*init) (void);
++ void (*exit) (void);
++
++} _inits[] = {
++#define xx(n) { init_ ## n, exit_ ## n}
++ xx(pages),
++ xx(buffers),
++ xx(jobs),
++ xx(copier)
++#undef xx
++};
++
++static int _client_count = 0;
++static DECLARE_MUTEX(_client_count_sem);
++
++static int kcopyd_init(void)
++{
++ const int count = sizeof(_inits) / sizeof(*_inits);
++
++ int r, i;
++
++ for (i = 0; i < count; i++) {
++ r = _inits[i].init();
++ if (r)
++ goto bad;
++ }
++
++ start_daemon();
++ return 0;
++
++ bad:
++ while (i--)
++ _inits[i].exit();
++
++ return r;
++}
++
++static void kcopyd_exit(void)
++{
++ int i = sizeof(_inits) / sizeof(*_inits);
++
++ if (stop_daemon())
++ DMWARN("Couldn't stop kcopyd.");
++
++ while (i--)
++ _inits[i].exit();
++}
++
++void kcopyd_inc_client_count(void)
++{
++ /*
++ * What I need here is an atomic_test_and_inc that returns
++ * the previous value of the atomic... In its absence I lock
++ * an int with a semaphore. :-(
++ */
++ down(&_client_count_sem);
++ if (_client_count == 0)
++ kcopyd_init();
++ _client_count++;
++
++ up(&_client_count_sem);
++}
++
++void kcopyd_dec_client_count(void)
++{
++ down(&_client_count_sem);
++ if (--_client_count == 0)
++ kcopyd_exit();
++
++ up(&_client_count_sem);
++}
+diff -ruN linux-2.4.19-rc1/drivers/md/kcopyd.h linux/drivers/md/kcopyd.h
+--- linux-2.4.19-rc1/drivers/md/kcopyd.h Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/kcopyd.h Tue Jun 25 22:39:45 2002
+@@ -0,0 +1,101 @@
++/*
++ * Copyright (C) 2001 Sistina Software
++ *
++ * This file is released under the GPL.
++ */
++
++#ifndef DM_KCOPYD_H
++#define DM_KCOPYD_H
++
++/*
++ * Needed for the definition of offset_t.
++ */
++#include <linux/device-mapper.h>
++#include <linux/iobuf.h>
++
++struct kcopyd_region {
++ kdev_t dev;
++ offset_t sector;
++ offset_t count;
++};
++
++#define MAX_KCOPYD_PAGES 128
++
++struct kcopyd_job {
++ struct list_head list;
++
++ /*
++ * Error state of the job.
++ */
++ int err;
++
++ /*
++ * Either READ or WRITE
++ */
++ int rw;
++
++ /*
++ * The source or destination for the transfer.
++ */
++ struct kcopyd_region disk;
++
++ int nr_pages;
++ struct page *pages[MAX_KCOPYD_PAGES];
++
++ /*
++ * Shifts and masks that will be useful when dispatching
++ * each buffer_head.
++ */
++ offset_t offset;
++ offset_t block_size;
++ offset_t block_shift;
++ offset_t bpp_shift; /* blocks per page */
++ offset_t bpp_mask;
++
++ /*
++ * nr_blocks is how many buffer heads will have to be
++ * displatched to service this job, nr_requested is how
++ * many have been dispatched and nr_complete is how many
++ * have come back.
++ */
++ unsigned int nr_blocks;
++ atomic_t nr_requested;
++ atomic_t nr_incomplete;
++
++ /*
++ * Set this to ensure you are notified when the job has
++ * completed. 'context' is for callback to use.
++ */
++ void (*callback)(struct kcopyd_job *job);
++ void *context;
++};
++
++/*
++ * Low level async io routines.
++ */
++struct kcopyd_job *kcopyd_alloc_job(void);
++void kcopyd_free_job(struct kcopyd_job *job);
++
++int kcopyd_queue_job(struct kcopyd_job *job);
++
++/*
++ * Submit a copy job to kcopyd. This is built on top of the
++ * previous three fns.
++ */
++typedef void (*kcopyd_notify_fn)(int err, void *context);
++
++int kcopyd_copy(struct kcopyd_region *from, struct kcopyd_region *to,
++ kcopyd_notify_fn fn, void *context);
++
++int kcopyd_write_pages(struct kcopyd_region *to, int nr_pages,
++ struct page **pages, int offset, kcopyd_notify_fn fn,
++ void *context);
++
++/*
++ * We only want kcopyd to reserve resources if someone is
++ * actually using it.
++ */
++void kcopyd_inc_client_count(void);
++void kcopyd_dec_client_count(void);
++
++#endif
--- /dev/null
+diff -ruN linux-2.4.19-rc1/drivers/md/Makefile linux/drivers/md/Makefile
+--- linux-2.4.19-rc1/drivers/md/Makefile Tue Jun 25 22:31:17 2002
++++ linux/drivers/md/Makefile Tue Jun 25 22:33:49 2002
+@@ -9,7 +9,7 @@
+ lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
+ dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o \
+ dm-linear.o dm-stripe.o dm-snapshot.o dm-exception-store.o \
+- kcopyd.o
++ kcopyd.o dm-mirror.o
+
+ # Note: link order is important. All raid personalities
+ # and xor.o must come before md.o, as they each initialise
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-mirror.c linux/drivers/md/dm-mirror.c
+--- linux-2.4.19-rc1/drivers/md/dm-mirror.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-mirror.c Tue Jun 25 22:33:59 2002
+@@ -0,0 +1,343 @@
++/*
++ * Copyright (C) 2002 Sistina Software (UK) Limited.
++ *
++ * This file is released under the GPL.
++ */
++
++#include "dm.h"
++#include "kcopyd.h"
++
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/blkdev.h>
++
++/* kcopyd priority of mirror operations */
++#define MIRROR_COPY_PRIORITY 5
++
++/*
++ * The percentage increment we will wake up users at
++ */
++#define WAKE_UP_PERCENT 5
++
++/*
++ * Mirror: maps a mirror range of a device.
++ */
++struct mirror_c {
++ struct dm_dev *fromdev;
++ struct dm_dev *todev;
++
++ unsigned long from_delta;
++ unsigned long to_delta;
++
++ unsigned long frompos;
++ unsigned long topos;
++
++ unsigned int chunksize;
++ unsigned long got_to;
++ unsigned long size;
++ struct rw_semaphore lock;
++ struct buffer_head *bhstring;
++
++ struct dm_table *table;
++
++ int last_percent;
++
++ int error;
++};
++
++/* Called when a duplicating I/O has finished */
++static void mirror_callback(int err, void *context)
++{
++ struct mirror_c *lc = (struct mirror_c *) context;
++
++ /* Flag error if it failed */
++ if (err) {
++ DMERR("Mirror copy to %s failed", kdevname(lc->todev->dev));
++ lc->error = 1;
++ dm_table_event(lc->table);
++ }
++}
++
++static void mirror_bh(struct mirror_c *mc, struct buffer_head *bh)
++{
++ struct kcopyd_region dest;
++
++ dest.dev = mc->todev->dev;
++ dest.sector = bh->b_rsector - mc->from_delta + mc->to_delta;
++ dest.count = bh->b_size / 512;
++ kcopyd_write_pages(&dest, 1, &bh->b_page,
++ ((long) bh->b_data -
++ (long) page_address(bh->b_page)) / 512,
++ mirror_callback, mc);
++}
++
++/* Called when the copy I/O has finished */
++static void copy_callback(int err, void *context)
++{
++ struct mirror_c *lc = (struct mirror_c *) context;
++ struct buffer_head *bh;
++
++ /* Submit, and mirror any pending BHs */
++ down_write(&lc->lock);
++
++ bh = lc->bhstring;
++ lc->bhstring = NULL;
++ up_write(&lc->lock);
++
++ while (bh) {
++ struct buffer_head *nextbh = bh->b_reqnext;
++ bh->b_reqnext = NULL;
++ mirror_bh(lc, bh);
++ generic_make_request(WRITE, bh);
++ bh = nextbh;
++ }
++
++ if (err) {
++ DMERR("Mirror block IO failed"); /* More detail to follow... */
++ lc->error = 1;
++ return;
++ }
++ if (lc->got_to + lc->chunksize < lc->size) {
++ int pc = (lc->got_to - lc->from_delta) * 100 / lc->size;
++ struct kcopyd_region src, dest;
++
++ /* Wake up any listeners if we've reached a milestone percentage */
++ if (pc >= lc->last_percent + WAKE_UP_PERCENT) {
++ dm_table_event(lc->table);
++ lc->last_percent = pc - pc % WAKE_UP_PERCENT;
++ }
++
++ /* Do next chunk */
++ lc->got_to += lc->chunksize;
++
++ src.dev = lc->fromdev->dev;
++ src.sector = lc->frompos + lc->got_to;
++ src.count = min((unsigned long) lc->chunksize,
++ lc->size - lc->got_to);
++
++ dest.dev = lc->todev->dev;
++ dest.sector = lc->topos + lc->got_to;
++ dest.count = src.count;
++
++ if (kcopyd_copy(&src, &dest, copy_callback, lc)) {
++ lc->error = 1;
++ return;
++ }
++ } else {
++ /* Finished */
++ dm_table_event(lc->table);
++ lc->got_to = lc->size;
++ }
++}
++
++/*
++ * Construct a mirror mapping: <dev_path1> <offset> <dev_path2> <offset> <chunk-size> [<priority>]
++ */
++static int mirror_ctr(struct dm_table *t, offset_t b, offset_t l,
++ int argc, char **argv, void **context)
++{
++ struct mirror_c *lc;
++ unsigned long offset1, offset2;
++ char *value;
++ int priority = MIRROR_COPY_PRIORITY;
++ int chunksize;
++ struct kcopyd_region src, dest;
++
++ if (argc <= 4) {
++ *context = "dm-mirror: Not enough arguments";
++ return -EINVAL;
++ }
++
++ lc = kmalloc(sizeof(*lc), GFP_KERNEL);
++ if (lc == NULL) {
++ *context = "dm-mirror: Cannot allocate mirror context";
++ return -ENOMEM;
++ }
++
++ if (dm_table_get_device(t, argv[0], 0, l, &lc->fromdev)) {
++ *context = "dm-mirror: Device lookup failed";
++ goto bad;
++ }
++
++ offset1 = simple_strtoul(argv[1], &value, 10);
++ if (value == NULL) {
++ *context = "Invalid offset for dev1";
++ dm_table_put_device(t, lc->fromdev);
++ goto bad;
++ }
++
++ if (dm_table_get_device(t, argv[2], 0, l, &lc->todev)) {
++ *context = "dm-mirror: Device lookup failed";
++ dm_table_put_device(t, lc->fromdev);
++ goto bad;
++ }
++
++ offset2 = simple_strtoul(argv[3], &value, 10);
++ if (value == NULL) {
++ *context = "Invalid offset for dev2";
++ goto bad_put;
++ }
++
++ chunksize = simple_strtoul(argv[4], &value, 10);
++ if (value == NULL || chunksize == 16) {
++ *context = "Invalid chunk size value";
++ goto bad_put;
++ }
++
++ if (argc > 5) {
++ priority = simple_strtoul(argv[5], &value, 10);
++ if (value == NULL) {
++ *context = "Invalid priority value";
++ goto bad_put;
++ }
++ }
++
++ lc->from_delta = (int) offset1 - (int) b;
++ lc->to_delta = (int) offset2 - (int) b;
++ lc->frompos = offset1;
++ lc->topos = offset2;
++ lc->error = 0;
++ lc->bhstring = NULL;
++ lc->size = l - offset1;
++ lc->last_percent = 0;
++ lc->got_to = 0;
++ lc->chunksize = chunksize;
++ lc->table = t;
++ init_rwsem(&lc->lock);
++ *context = lc;
++
++ /* Tell kcopyd to do the biz */
++ src.dev = lc->fromdev->dev;
++ src.sector = offset1;
++ src.count = min((unsigned long) chunksize, lc->size);
++
++ dest.dev = lc->todev->dev;
++ dest.sector = offset2;
++ dest.count = src.count;
++
++ kcopyd_inc_client_count();
++
++ if (kcopyd_copy(&src, &dest, copy_callback, lc)) {
++ DMERR("block copy call failed");
++ dm_table_put_device(t, lc->fromdev);
++ dm_table_put_device(t, lc->todev);
++ kcopyd_dec_client_count();
++ goto bad;
++ }
++ return 0;
++
++ bad_put:
++ dm_table_put_device(t, lc->fromdev);
++ dm_table_put_device(t, lc->todev);
++ bad:
++ kfree(lc);
++ return -EINVAL;
++}
++
++static void mirror_dtr(struct dm_table *t, void *c)
++{
++ struct mirror_c *lc = (struct mirror_c *) c;
++
++ dm_table_put_device(t, lc->fromdev);
++ dm_table_put_device(t, lc->todev);
++ kfree(c);
++ kcopyd_dec_client_count();
++}
++
++static int mirror_map(struct buffer_head *bh, int rw, void *context)
++{
++ struct mirror_c *lc = (struct mirror_c *) context;
++
++ bh->b_rdev = lc->fromdev->dev;
++ bh->b_rsector = bh->b_rsector + lc->from_delta;
++
++ if (rw == WRITE) {
++ down_write(&lc->lock);
++
++ /*
++ * If this area is in flight then save it until it's
++ * committed to the mirror disk and then submit it and
++ * its mirror.
++ */
++ if (bh->b_rsector > lc->got_to &&
++ bh->b_rsector <= lc->got_to + lc->chunksize) {
++ bh->b_reqnext = lc->bhstring;
++ lc->bhstring = bh;
++ up_write(&lc->lock);
++ return 0;
++ }
++
++ /*
++ * If we've already copied this block then duplicate
++ * it to the mirror device
++ */
++ if (bh->b_rsector < lc->got_to) {
++ mirror_bh(lc, bh);
++ }
++ up_write(&lc->lock);
++ }
++ return 1;
++}
++
++static int mirror_status(status_type_t sts_type, char *result, int maxlen,
++ void *context)
++{
++ struct mirror_c *mc = (struct mirror_c *) context;
++
++ switch (sts_type) {
++ case STATUSTYPE_INFO:
++ if (mc->error)
++ snprintf(result, maxlen, "Error");
++ else
++ snprintf(result, maxlen, "%ld%%",
++ (mc->got_to -
++ mc->from_delta) * 100 / mc->size);
++ break;
++
++ case STATUSTYPE_TABLE:
++ snprintf(result, maxlen, "%s %ld %s %ld %d",
++ kdevname(mc->fromdev->dev), mc->frompos,
++ kdevname(mc->todev->dev), mc->topos, mc->chunksize);
++ break;
++ }
++ return 0;
++}
++
++static struct target_type mirror_target = {
++ name: "mirror",
++ module: THIS_MODULE,
++ ctr: mirror_ctr,
++ dtr: mirror_dtr,
++ map: mirror_map,
++ status: mirror_status,
++};
++
++int __init dm_mirror_init(void)
++{
++ int r;
++
++ r = dm_register_target(&mirror_target);
++ if (r < 0) {
++ DMERR("mirror: register failed %d", r);
++ }
++ return r;
++}
++
++void dm_mirror_exit(void)
++{
++ int r = dm_unregister_target(&mirror_target);
++
++ if (r < 0)
++ DMERR("mirror: unregister failed %d", r);
++}
++
++/*
++ * Overrides for Emacs so that we follow Linus's tabbing style.
++ * Emacs will notice this stuff at the end of the file and automatically
++ * adjust the settings for this buffer only. This must remain at the end
++ * of the file.
++ * ---------------------------------------------------------------------------
++ * Local variables:
++ * c-file-style: "linux"
++ * End:
++ */
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.c linux/drivers/md/dm.c
+--- linux-2.4.19-rc1/drivers/md/dm.c Tue Jun 25 22:31:54 2002
++++ linux/drivers/md/dm.c Tue Jun 25 22:34:34 2002
+@@ -270,6 +270,7 @@
+ xx(dm_linear)
+ xx(dm_stripe)
+ xx(dm_snapshot)
++ xx(dm_mirror)
+ xx(dm_interface)
+ #undef xx
+ };
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.h linux/drivers/md/dm.h
+--- linux-2.4.19-rc1/drivers/md/dm.h Tue Jun 25 22:33:11 2002
++++ linux/drivers/md/dm.h Tue Jun 25 22:34:15 2002
+@@ -183,6 +183,10 @@
+ int dm_snapshot_init(void);
+ void dm_snapshot_exit(void);
+
++/* dm-mirror.c */
++int dm_mirror_init(void);
++void dm_mirror_exit(void);
++
+ #define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
+ #define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x)
+ #define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x)
--- /dev/null
+diff -Nru linux-2.4.19-rc1/include/linux/mempool.h linux/include/linux/mempool.h
+--- /dev/null Wed Dec 31 16:00:00 1969
++++ linux/include/linux/mempool.h Tue Apr 23 20:55:52 2002
+@@ -0,0 +1,33 @@
++/*
++ * memory buffer pool support
++ */
++#ifndef _LINUX_MEMPOOL_H
++#define _LINUX_MEMPOOL_H
++
++#include <linux/list.h>
++#include <linux/wait.h>
++
++struct mempool_s;
++typedef struct mempool_s mempool_t;
++
++typedef void * (mempool_alloc_t)(int gfp_mask, void *pool_data);
++typedef void (mempool_free_t)(void *element, void *pool_data);
++
++struct mempool_s {
++ spinlock_t lock;
++ int min_nr, curr_nr;
++ struct list_head elements;
++
++ void *pool_data;
++ mempool_alloc_t *alloc;
++ mempool_free_t *free;
++ wait_queue_head_t wait;
++};
++extern mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
++ mempool_free_t *free_fn, void *pool_data);
++extern void mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask);
++extern void mempool_destroy(mempool_t *pool);
++extern void * mempool_alloc(mempool_t *pool, int gfp_mask);
++extern void mempool_free(void *element, mempool_t *pool);
++
++#endif /* _LINUX_MEMPOOL_H */
+diff -Nru linux-2.4.19-rc1/mm/Makefile linux/mm/Makefile
+--- linux-2.4.19-rc1/mm/Makefile Mon Mar 25 14:40:15 2002
++++ linux/mm/Makefile Mon Mar 25 14:40:15 2002
+@@ -9,12 +9,12 @@
+
+ O_TARGET := mm.o
+
+-export-objs := shmem.o filemap.o memory.o page_alloc.o
++export-objs := shmem.o filemap.o memory.o page_alloc.o mempool.o
+
+ obj-y := memory.o mmap.o filemap.o mprotect.o mlock.o mremap.o \
+ vmalloc.o slab.o bootmem.o swap.o vmscan.o page_io.o \
+ page_alloc.o swap_state.o swapfile.o numa.o oom_kill.o \
+- shmem.o
++ shmem.o mempool.o
+
+ obj-$(CONFIG_HIGHMEM) += highmem.o
+
+diff -Nru linux-2.4.19-rc1/mm/mempool.c b/mm/mempool.c
+--- /dev/null Wed Dec 31 16:00:00 1969
++++ linux/mm/mempool.c Tue Apr 23 20:55:52 2002
+@@ -0,0 +1,277 @@
++/*
++ * linux/mm/mempool.c
++ *
++ * memory buffer pool support. Such pools are mostly used
++ * for guaranteed, deadlock-free memory allocations during
++ * extreme VM load.
++ *
++ * started by Ingo Molnar, Copyright (C) 2001
++ */
++
++#include <linux/mm.h>
++#include <linux/slab.h>
++#include <linux/module.h>
++#include <linux/mempool.h>
++#include <linux/compiler.h>
++
++/**
++ * mempool_create - create a memory pool
++ * @min_nr: the minimum number of elements guaranteed to be
++ * allocated for this pool.
++ * @alloc_fn: user-defined element-allocation function.
++ * @free_fn: user-defined element-freeing function.
++ * @pool_data: optional private data available to the user-defined functions.
++ *
++ * this function creates and allocates a guaranteed size, preallocated
++ * memory pool. The pool can be used from the mempool_alloc and mempool_free
++ * functions. This function might sleep. Both the alloc_fn() and the free_fn()
++ * functions might sleep - as long as the mempool_alloc function is not called
++ * from IRQ contexts. The element allocated by alloc_fn() must be able to
++ * hold a struct list_head. (8 bytes on x86.)
++ */
++mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
++ mempool_free_t *free_fn, void *pool_data)
++{
++ mempool_t *pool;
++ int i;
++
++ pool = kmalloc(sizeof(*pool), GFP_KERNEL);
++ if (!pool)
++ return NULL;
++ memset(pool, 0, sizeof(*pool));
++
++ spin_lock_init(&pool->lock);
++ pool->min_nr = min_nr;
++ pool->pool_data = pool_data;
++ INIT_LIST_HEAD(&pool->elements);
++ init_waitqueue_head(&pool->wait);
++ pool->alloc = alloc_fn;
++ pool->free = free_fn;
++
++ /*
++ * First pre-allocate the guaranteed number of buffers.
++ */
++ for (i = 0; i < min_nr; i++) {
++ void *element;
++ struct list_head *tmp;
++ element = pool->alloc(GFP_KERNEL, pool->pool_data);
++
++ if (unlikely(!element)) {
++ /*
++ * Not enough memory - free the allocated ones
++ * and return:
++ */
++ list_for_each(tmp, &pool->elements) {
++ element = tmp;
++ pool->free(element, pool->pool_data);
++ }
++ kfree(pool);
++
++ return NULL;
++ }
++ tmp = element;
++ list_add(tmp, &pool->elements);
++ pool->curr_nr++;
++ }
++ return pool;
++}
++
++/**
++ * mempool_resize - resize an existing memory pool
++ * @pool: pointer to the memory pool which was allocated via
++ * mempool_create().
++ * @new_min_nr: the new minimum number of elements guaranteed to be
++ * allocated for this pool.
++ * @gfp_mask: the usual allocation bitmask.
++ *
++ * This function shrinks/grows the pool. In the case of growing,
++ * it cannot be guaranteed that the pool will be grown to the new
++ * size immediately, but new mempool_free() calls will refill it.
++ *
++ * Note, the caller must guarantee that no mempool_destroy is called
++ * while this function is running. mempool_alloc() & mempool_free()
++ * might be called (eg. from IRQ contexts) while this function executes.
++ */
++void mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask)
++{
++ int delta;
++ void *element;
++ unsigned long flags;
++ struct list_head *tmp;
++
++ if (new_min_nr <= 0)
++ BUG();
++
++ spin_lock_irqsave(&pool->lock, flags);
++ if (new_min_nr < pool->min_nr) {
++ pool->min_nr = new_min_nr;
++ /*
++ * Free possible excess elements.
++ */
++ while (pool->curr_nr > pool->min_nr) {
++ tmp = pool->elements.next;
++ if (tmp == &pool->elements)
++ BUG();
++ list_del(tmp);
++ element = tmp;
++ pool->curr_nr--;
++ spin_unlock_irqrestore(&pool->lock, flags);
++
++ pool->free(element, pool->pool_data);
++
++ spin_lock_irqsave(&pool->lock, flags);
++ }
++ spin_unlock_irqrestore(&pool->lock, flags);
++ return;
++ }
++ delta = new_min_nr - pool->min_nr;
++ pool->min_nr = new_min_nr;
++ spin_unlock_irqrestore(&pool->lock, flags);
++
++ /*
++ * We refill the pool up to the new treshold - but we dont
++ * (cannot) guarantee that the refill succeeds.
++ */
++ while (delta) {
++ element = pool->alloc(gfp_mask, pool->pool_data);
++ if (!element)
++ break;
++ mempool_free(element, pool);
++ delta--;
++ }
++}
++
++/**
++ * mempool_destroy - deallocate a memory pool
++ * @pool: pointer to the memory pool which was allocated via
++ * mempool_create().
++ *
++ * this function only sleeps if the free_fn() function sleeps. The caller
++ * has to guarantee that no mempool_alloc() nor mempool_free() happens in
++ * this pool when calling this function.
++ */
++void mempool_destroy(mempool_t *pool)
++{
++ void *element;
++ struct list_head *head, *tmp;
++
++ if (!pool)
++ return;
++
++ head = &pool->elements;
++ for (tmp = head->next; tmp != head; ) {
++ element = tmp;
++ tmp = tmp->next;
++ pool->free(element, pool->pool_data);
++ pool->curr_nr--;
++ }
++ if (pool->curr_nr)
++ BUG();
++ kfree(pool);
++}
++
++/**
++ * mempool_alloc - allocate an element from a specific memory pool
++ * @pool: pointer to the memory pool which was allocated via
++ * mempool_create().
++ * @gfp_mask: the usual allocation bitmask.
++ *
++ * this function only sleeps if the alloc_fn function sleeps or
++ * returns NULL. Note that due to preallocation, this function
++ * *never* fails when called from process contexts. (it might
++ * fail if called from an IRQ context.)
++ */
++void * mempool_alloc(mempool_t *pool, int gfp_mask)
++{
++ void *element;
++ unsigned long flags;
++ struct list_head *tmp;
++ int curr_nr;
++ DECLARE_WAITQUEUE(wait, current);
++ int gfp_nowait = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
++
++repeat_alloc:
++ element = pool->alloc(gfp_nowait, pool->pool_data);
++ if (likely(element != NULL))
++ return element;
++
++ /*
++ * If the pool is less than 50% full then try harder
++ * to allocate an element:
++ */
++ if ((gfp_mask != gfp_nowait) && (pool->curr_nr <= pool->min_nr/2)) {
++ element = pool->alloc(gfp_mask, pool->pool_data);
++ if (likely(element != NULL))
++ return element;
++ }
++
++ /*
++ * Kick the VM at this point.
++ */
++ wakeup_bdflush();
++
++ spin_lock_irqsave(&pool->lock, flags);
++ if (likely(pool->curr_nr)) {
++ tmp = pool->elements.next;
++ list_del(tmp);
++ element = tmp;
++ pool->curr_nr--;
++ spin_unlock_irqrestore(&pool->lock, flags);
++ return element;
++ }
++ spin_unlock_irqrestore(&pool->lock, flags);
++
++ /* We must not sleep in the GFP_ATOMIC case */
++ if (gfp_mask == gfp_nowait)
++ return NULL;
++
++ run_task_queue(&tq_disk);
++
++ add_wait_queue_exclusive(&pool->wait, &wait);
++ set_task_state(current, TASK_UNINTERRUPTIBLE);
++
++ spin_lock_irqsave(&pool->lock, flags);
++ curr_nr = pool->curr_nr;
++ spin_unlock_irqrestore(&pool->lock, flags);
++
++ if (!curr_nr)
++ schedule();
++
++ current->state = TASK_RUNNING;
++ remove_wait_queue(&pool->wait, &wait);
++
++ goto repeat_alloc;
++}
++
++/**
++ * mempool_free - return an element to the pool.
++ * @element: pool element pointer.
++ * @pool: pointer to the memory pool which was allocated via
++ * mempool_create().
++ *
++ * this function only sleeps if the free_fn() function sleeps.
++ */
++void mempool_free(void *element, mempool_t *pool)
++{
++ unsigned long flags;
++
++ if (pool->curr_nr < pool->min_nr) {
++ spin_lock_irqsave(&pool->lock, flags);
++ if (pool->curr_nr < pool->min_nr) {
++ list_add(element, &pool->elements);
++ pool->curr_nr++;
++ spin_unlock_irqrestore(&pool->lock, flags);
++ wake_up(&pool->wait);
++ return;
++ }
++ spin_unlock_irqrestore(&pool->lock, flags);
++ }
++ pool->free(element, pool->pool_data);
++}
++
++EXPORT_SYMBOL(mempool_create);
++EXPORT_SYMBOL(mempool_resize);
++EXPORT_SYMBOL(mempool_destroy);
++EXPORT_SYMBOL(mempool_alloc);
++EXPORT_SYMBOL(mempool_free);
++
--- /dev/null
+diff -Nru linux-2.4.19-rc1/include/linux/mempool.h linux/include/linux/mempool.h
+--- linux-2.4.19-rc1/include/linux/mempool.h Wed Dec 31 16:00:00 2001
++++ linux/include/linux/mempool.h Tue Apr 23 20:55:52 2002
+@@ -29,5 +29,13 @@
+ extern void mempool_destroy(mempool_t *pool);
+ extern void * mempool_alloc(mempool_t *pool, int gfp_mask);
+ extern void mempool_free(void *element, mempool_t *pool);
+
++
++/*
++ * A mempool_alloc_t and mempool_free_t that get the memory from
++ * a slab that is passed in through pool_data.
++ */
++void *mempool_alloc_slab(int gfp_mask, void *pool_data);
++void mempool_free_slab(void *element, void *pool_data);
++
+ #endif /* _LINUX_MEMPOOL_H */
+diff -Nru linux-2.4.19-rc1/mm/mempool.c linux/mm/mempool.c
+--- linux-2.4.19-rc1/mm/mempool.c Wed Dec 31 16:00:00 1969
++++ linux/mm/mempool.c Tue Apr 23 20:55:52 2002
+@@ -268,10 +268,28 @@
+ }
+ pool->free(element, pool->pool_data);
+ }
+
++/*
++ * A commonly used alloc and free fn.
++ */
++void *mempool_alloc_slab(int gfp_mask, void *pool_data)
++{
++ kmem_cache_t *mem = (kmem_cache_t *) pool_data;
++ return kmem_cache_alloc(mem, gfp_mask);
++}
++
++void mempool_free_slab(void *element, void *pool_data)
++{
++ kmem_cache_t *mem = (kmem_cache_t *) pool_data;
++ kmem_cache_free(mem, element);
++}
++
++
+ EXPORT_SYMBOL(mempool_create);
+ EXPORT_SYMBOL(mempool_resize);
+ EXPORT_SYMBOL(mempool_destroy);
+ EXPORT_SYMBOL(mempool_alloc);
+ EXPORT_SYMBOL(mempool_free);
++EXPORT_SYMBOL(mempool_alloc_slab);
++EXPORT_SYMBOL(mempool_free_slab);
+
--- /dev/null
+diff -Nru linux-2.4.19-rc1/mm/vmalloc.c linux/mm/vmalloc.c
+--- linux-2.4.19-rc1/mm/vmalloc.c Wed Jun 12 12:04:44 2002
++++ linux/mm/vmalloc.c Thu Jun 13 13:13:44 2002
+@@ -321,3 +321,22 @@
+ read_unlock(&vmlist_lock);
+ return buf - buf_start;
+ }
++
++void *vcalloc(unsigned long nmemb, unsigned long elem_size)
++{
++ unsigned long size;
++ void *addr;
++
++ /*
++ * Check that we're not going to overflow.
++ */
++ if (nmemb > (ULONG_MAX / elem_size))
++ return NULL;
++
++ size = nmemb * elem_size;
++ addr = vmalloc(size);
++ if (addr)
++ memset(addr, 0, size);
++
++ return addr;
++}
+diff -Nru linux-2.4.19-rc1/include/linux/vmalloc.h linux/include/linux/vmalloc.h
+--- linux-2.4.19-rc1/include/linux/vmalloc.h Wed Jun 12 12:35:58 2002
++++ linux/include/linux/vmalloc.h Thu Jun 13 13:13:39 2002
+@@ -25,6 +25,7 @@
+ extern void vmfree_area_pages(unsigned long address, unsigned long size);
+ extern int vmalloc_area_pages(unsigned long address, unsigned long size,
+ int gfp_mask, pgprot_t prot);
++extern void *vcalloc(unsigned long nmemb, unsigned long elem_size);
+
+ /*
+ * Allocate any pages
+++ /dev/null
-diff -ruN linux-2.4.19-pre8/drivers/md/Config.in linux/drivers/md/Config.in
---- linux-2.4.19-pre8/drivers/md/Config.in Mon May 20 16:37:23 2002
-+++ linux/drivers/md/Config.in Mon May 20 16:58:11 2002
-@@ -14,5 +14,6 @@
- dep_tristate ' Multipath I/O support' CONFIG_MD_MULTIPATH $CONFIG_BLK_DEV_MD
-
- dep_tristate ' Logical volume manager (LVM) support' CONFIG_BLK_DEV_LVM $CONFIG_MD
-+dep_tristate ' Device mapper support' CONFIG_BLK_DEV_DM $CONFIG_MD
-
- endmenu
-diff -ruN linux-2.4.19-pre8/drivers/md/Makefile linux/drivers/md/Makefile
---- linux-2.4.19-pre8/drivers/md/Makefile Mon May 20 16:37:23 2002
-+++ linux/drivers/md/Makefile Mon May 20 17:03:40 2002
-@@ -4,9 +4,12 @@
-
- O_TARGET := mddev.o
-
--export-objs := md.o xor.o
-+export-objs := md.o xor.o dm-table.o dm-target.o kcopyd.o
- list-multi := lvm-mod.o
- lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o
-+dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o \
-+ dm-linear.o dm-stripe.o dm-snapshot.o dm-exception-store.o \
-+ kcopyd.o
-
- # Note: link order is important. All raid personalities
- # and xor.o must come before md.o, as they each initialise
-@@ -20,8 +23,12 @@
- obj-$(CONFIG_MD_MULTIPATH) += multipath.o
- obj-$(CONFIG_BLK_DEV_MD) += md.o
- obj-$(CONFIG_BLK_DEV_LVM) += lvm-mod.o
-+obj-$(CONFIG_BLK_DEV_DM) += dm-mod.o
-
- include $(TOPDIR)/Rules.make
-
- lvm-mod.o: $(lvm-mod-objs)
- $(LD) -r -o $@ $(lvm-mod-objs)
-+
-+dm-mod.o: $(dm-mod-objs)
-+ $(LD) -r -o $@ $(dm-mod-objs)
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-exception-store.c linux/drivers/md/dm-exception-store.c
---- linux-2.4.19-pre8/drivers/md/dm-exception-store.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-exception-store.c Mon May 20 14:29:15 2002
-@@ -0,0 +1,727 @@
-+/*
-+ * dm-snapshot.c
-+ *
-+ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm-snapshot.h"
-+#include "kcopyd.h"
-+#include <linux/mm.h>
-+#include <linux/pagemap.h>
-+
-+#define SECTOR_SIZE 512
-+#define SECTOR_SHIFT 9
-+
-+/*-----------------------------------------------------------------
-+ * Persistent snapshots, by persistent we mean that the snapshot
-+ * will survive a reboot.
-+ *---------------------------------------------------------------*/
-+
-+/*
-+ * We need to store a record of which parts of the origin have
-+ * been copied to the snapshot device. The snapshot code
-+ * requires that we copy exception chunks to chunk aligned areas
-+ * of the COW store. It makes sense therefore, to store the
-+ * metadata in chunk size blocks.
-+ *
-+ * There is no backward or forward compatibility implemented,
-+ * snapshots with different disk versions than the kernel will
-+ * not be usable. It is expected that "lvcreate" will blank out
-+ * the start of a fresh COW device before calling the snapshot
-+ * constructor.
-+ *
-+ * The first chunk of the COW device just contains the header.
-+ * After this there is a chunk filled with exception metadata,
-+ * followed by as many exception chunks as can fit in the
-+ * metadata areas.
-+ *
-+ * All on disk structures are in little-endian format. The end
-+ * of the exceptions info is indicated by an exception with a
-+ * new_chunk of 0, which is invalid since it would point to the
-+ * header chunk.
-+ */
-+
-+/*
-+ * Magic for persistent snapshots: "SnAp" - Feeble isn't it.
-+ */
-+#define SNAP_MAGIC 0x70416e53
-+
-+/*
-+ * The on-disk version of the metadata.
-+ */
-+#define SNAPSHOT_DISK_VERSION 1
-+
-+struct disk_header {
-+ uint32_t magic;
-+
-+ /*
-+ * Is this snapshot valid. There is no way of recovering
-+ * an invalid snapshot.
-+ */
-+ int valid;
-+
-+ /*
-+ * Simple, incrementing version. no backward
-+ * compatibility.
-+ */
-+ uint32_t version;
-+
-+ /* In sectors */
-+ uint32_t chunk_size;
-+};
-+
-+struct disk_exception {
-+ uint64_t old_chunk;
-+ uint64_t new_chunk;
-+};
-+
-+struct commit_callback {
-+ void (*callback)(void *, int success);
-+ void *context;
-+};
-+
-+/*
-+ * The top level structure for a persistent exception store.
-+ */
-+struct pstore {
-+ struct dm_snapshot *snap; /* up pointer to my snapshot */
-+ int version;
-+ int valid;
-+ uint32_t chunk_size;
-+ uint32_t exceptions_per_area;
-+
-+ /*
-+ * Now that we have an asynchronous kcopyd there is no
-+ * need for large chunk sizes, so it wont hurt to have a
-+ * whole chunks worth of metadata in memory at once.
-+ */
-+ void *area;
-+ struct kiobuf *iobuf;
-+
-+ /*
-+ * Used to keep track of which metadata area the data in
-+ * 'chunk' refers to.
-+ */
-+ uint32_t current_area;
-+
-+ /*
-+ * The next free chunk for an exception.
-+ */
-+ uint32_t next_free;
-+
-+ /*
-+ * The index of next free exception in the current
-+ * metadata area.
-+ */
-+ uint32_t current_committed;
-+
-+ atomic_t pending_count;
-+ uint32_t callback_count;
-+ struct commit_callback *callbacks;
-+};
-+
-+/*
-+ * For performance reasons we want to defer writing a committed
-+ * exceptions metadata to disk so that we can amortise away this
-+ * exensive operation.
-+ *
-+ * For the initial version of this code we will remain with
-+ * synchronous io. There are some deadlock issues with async
-+ * that I haven't yet worked out.
-+ */
-+static int do_io(int rw, struct kcopyd_region *where, struct kiobuf *iobuf)
-+{
-+ int i, sectors_per_block, nr_blocks, start;
-+ int blocksize = get_hardsect_size(where->dev);
-+ int status;
-+
-+ sectors_per_block = blocksize / SECTOR_SIZE;
-+
-+ nr_blocks = where->count / sectors_per_block;
-+ start = where->sector / sectors_per_block;
-+
-+ for (i = 0; i < nr_blocks; i++)
-+ iobuf->blocks[i] = start++;
-+
-+ iobuf->length = where->count << 9;
-+ iobuf->locked = 1;
-+
-+ status = brw_kiovec(rw, 1, &iobuf, where->dev, iobuf->blocks,
-+ blocksize);
-+ if (status != (where->count << 9))
-+ return -EIO;
-+
-+ return 0;
-+}
-+
-+#if LINUX_VERSION_CODE < KERNEL_VERSION ( 2, 4, 19)
-+/*
-+ * FIXME: Remove once 2.4.19 has been released.
-+ */
-+struct page *vmalloc_to_page(void *vmalloc_addr)
-+{
-+ unsigned long addr = (unsigned long) vmalloc_addr;
-+ struct page *page = NULL;
-+ pmd_t *pmd;
-+ pte_t *pte;
-+ pgd_t *pgd;
-+
-+ pgd = pgd_offset_k(addr);
-+ if (!pgd_none(*pgd)) {
-+ pmd = pmd_offset(pgd, addr);
-+ if (!pmd_none(*pmd)) {
-+ pte = pte_offset(pmd, addr);
-+ if (pte_present(*pte)) {
-+ page = pte_page(*pte);
-+ }
-+ }
-+ }
-+ return page;
-+}
-+#endif
-+
-+static int allocate_iobuf(struct pstore *ps)
-+{
-+ size_t i, r = -ENOMEM, len, nr_pages;
-+ struct page *page;
-+
-+ len = ps->chunk_size << SECTOR_SHIFT;
-+
-+ /*
-+ * Allocate the chunk_size block of memory that will hold
-+ * a single metadata area.
-+ */
-+ ps->area = vmalloc(len);
-+ if (!ps->area)
-+ return r;
-+
-+ if (alloc_kiovec(1, &ps->iobuf))
-+ goto bad;
-+
-+ if (alloc_kiobuf_bhs(ps->iobuf))
-+ goto bad;
-+
-+ nr_pages = ps->chunk_size / (PAGE_SIZE / SECTOR_SIZE);
-+ r = expand_kiobuf(ps->iobuf, nr_pages);
-+ if (r)
-+ goto bad;
-+
-+ /*
-+ * We lock the pages for ps->area into memory since they'll be
-+ * doing a lot of io.
-+ */
-+ for (i = 0; i < nr_pages; i++) {
-+ page = vmalloc_to_page(ps->area + (i * PAGE_SIZE));
-+ LockPage(page);
-+ ps->iobuf->maplist[i] = page;
-+ ps->iobuf->nr_pages++;
-+ }
-+
-+ ps->iobuf->nr_pages = nr_pages;
-+ ps->iobuf->offset = 0;
-+
-+ return 0;
-+
-+ bad:
-+ if (ps->iobuf)
-+ free_kiovec(1, &ps->iobuf);
-+
-+ if (ps->area)
-+ vfree(ps->area);
-+ ps->iobuf = NULL;
-+ return r;
-+}
-+
-+static void free_iobuf(struct pstore *ps)
-+{
-+ int i;
-+
-+ for (i = 0; i < ps->iobuf->nr_pages; i++)
-+ UnlockPage(ps->iobuf->maplist[i]);
-+ ps->iobuf->locked = 0;
-+
-+ free_kiovec(1, &ps->iobuf);
-+ vfree(ps->area);
-+}
-+
-+/*
-+ * Read or write a chunk aligned and sized block of data from a device.
-+ */
-+static int chunk_io(struct pstore *ps, uint32_t chunk, int rw)
-+{
-+ int r;
-+ struct kcopyd_region where;
-+
-+ where.dev = ps->snap->cow->dev;
-+ where.sector = ps->chunk_size * chunk;
-+ where.count = ps->chunk_size;
-+
-+ r = do_io(rw, &where, ps->iobuf);
-+ if (r)
-+ return r;
-+
-+ return 0;
-+}
-+
-+/*
-+ * Read or write a metadata area. Remembering to skip the first
-+ * chunk which holds the header.
-+ */
-+static int area_io(struct pstore *ps, uint32_t area, int rw)
-+{
-+ int r;
-+ uint32_t chunk;
-+
-+ /* convert a metadata area index to a chunk index */
-+ chunk = 1 + ((ps->exceptions_per_area + 1) * area);
-+
-+ r = chunk_io(ps, chunk, rw);
-+ if (r)
-+ return r;
-+
-+ ps->current_area = area;
-+ return 0;
-+}
-+
-+static int zero_area(struct pstore *ps, uint32_t area)
-+{
-+ memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
-+ return area_io(ps, area, WRITE);
-+}
-+
-+static int read_header(struct pstore *ps, int *new_snapshot)
-+{
-+ int r;
-+ struct disk_header *dh;
-+
-+ r = chunk_io(ps, 0, READ);
-+ if (r)
-+ return r;
-+
-+ dh = (struct disk_header *) ps->area;
-+
-+ if (dh->magic == 0) {
-+ *new_snapshot = 1;
-+
-+ } else if (dh->magic == SNAP_MAGIC) {
-+ *new_snapshot = 0;
-+ ps->valid = dh->valid;
-+ ps->version = dh->version;
-+ ps->chunk_size = dh->chunk_size;
-+
-+ } else {
-+ DMWARN("Invalid/corrupt snapshot");
-+ r = -ENXIO;
-+ }
-+
-+ return r;
-+}
-+
-+static int write_header(struct pstore *ps)
-+{
-+ struct disk_header *dh;
-+
-+ memset(ps->area, 0, ps->chunk_size << SECTOR_SHIFT);
-+
-+ dh = (struct disk_header *) ps->area;
-+ dh->magic = SNAP_MAGIC;
-+ dh->valid = ps->valid;
-+ dh->version = ps->version;
-+ dh->chunk_size = ps->chunk_size;
-+
-+ return chunk_io(ps, 0, WRITE);
-+}
-+
-+/*
-+ * Access functions for the disk exceptions, these do the endian conversions.
-+ */
-+static struct disk_exception *get_exception(struct pstore *ps, uint32_t index)
-+{
-+ if (index >= ps->exceptions_per_area)
-+ return NULL;
-+
-+ return ((struct disk_exception *) ps->area) + index;
-+}
-+
-+static int read_exception(struct pstore *ps,
-+ uint32_t index, struct disk_exception *result)
-+{
-+ struct disk_exception *e;
-+
-+ e = get_exception(ps, index);
-+ if (!e)
-+ return -EINVAL;
-+
-+ /* copy it */
-+ result->old_chunk = le64_to_cpu(e->old_chunk);
-+ result->new_chunk = le64_to_cpu(e->new_chunk);
-+
-+ return 0;
-+}
-+
-+static int write_exception(struct pstore *ps,
-+ uint32_t index, struct disk_exception *de)
-+{
-+ struct disk_exception *e;
-+
-+ e = get_exception(ps, index);
-+ if (!e)
-+ return -EINVAL;
-+
-+ /* copy it */
-+ e->old_chunk = cpu_to_le64(de->old_chunk);
-+ e->new_chunk = cpu_to_le64(de->new_chunk);
-+
-+ return 0;
-+}
-+
-+/*
-+ * Registers the exceptions that are present in the current area.
-+ * 'full' is filled in to indicate if the area has been
-+ * filled.
-+ */
-+static int insert_exceptions(struct pstore *ps, int *full)
-+{
-+ int i, r;
-+ struct disk_exception de;
-+
-+ /* presume the area is full */
-+ *full = 1;
-+
-+ for (i = 0; i < ps->exceptions_per_area; i++) {
-+ r = read_exception(ps, i, &de);
-+
-+ if (r)
-+ return r;
-+
-+ /*
-+ * If the new_chunk is pointing at the start of
-+ * the COW device, where the first metadata area
-+ * is we know that we've hit the end of the
-+ * exceptions. Therefore the area is not full.
-+ */
-+ if (de.new_chunk == 0LL) {
-+ ps->current_committed = i;
-+ *full = 0;
-+ break;
-+ }
-+
-+ /*
-+ * Keep track of the start of the free chunks.
-+ */
-+ if (ps->next_free <= de.new_chunk)
-+ ps->next_free = de.new_chunk + 1;
-+
-+ /*
-+ * Otherwise we add the exception to the snapshot.
-+ */
-+ r = dm_add_exception(ps->snap, de.old_chunk, de.new_chunk);
-+ if (r)
-+ return r;
-+ }
-+
-+ return 0;
-+}
-+
-+static int read_exceptions(struct pstore *ps)
-+{
-+ uint32_t area;
-+ int r, full = 1;
-+
-+ /*
-+ * Keeping reading chunks and inserting exceptions until
-+ * we find a partially full area.
-+ */
-+ for (area = 0; full; area++) {
-+ r = area_io(ps, area, READ);
-+ if (r)
-+ return r;
-+
-+ r = insert_exceptions(ps, &full);
-+ if (r)
-+ return r;
-+
-+ area++;
-+ }
-+
-+ return 0;
-+}
-+
-+static inline struct pstore *get_info(struct exception_store *store)
-+{
-+ return (struct pstore *) store->context;
-+}
-+
-+static int persistent_percentfull(struct exception_store *store)
-+{
-+ struct pstore *ps = get_info(store);
-+ return (ps->next_free * store->snap->chunk_size * 100) /
-+ get_dev_size(store->snap->cow->dev);
-+}
-+
-+static void persistent_destroy(struct exception_store *store)
-+{
-+ struct pstore *ps = get_info(store);
-+
-+ vfree(ps->callbacks);
-+ free_iobuf(ps);
-+ kfree(ps);
-+}
-+
-+static int persistent_prepare(struct exception_store *store,
-+ struct exception *e)
-+{
-+ struct pstore *ps = get_info(store);
-+ uint32_t stride;
-+ offset_t size = get_dev_size(store->snap->cow->dev);
-+
-+ /* Is there enough room ? */
-+ if (size <= (ps->next_free * store->snap->chunk_size))
-+ return -ENOSPC;
-+
-+ e->new_chunk = ps->next_free;
-+
-+ /*
-+ * Move onto the next free pending, making sure to take
-+ * into account the location of the metadata chunks.
-+ */
-+ stride = (ps->exceptions_per_area + 1);
-+ if (!(++ps->next_free % stride))
-+ ps->next_free++;
-+
-+ atomic_inc(&ps->pending_count);
-+ return 0;
-+}
-+
-+static void persistent_commit(struct exception_store *store,
-+ struct exception *e,
-+ void (*callback) (void *, int success),
-+ void *callback_context)
-+{
-+ int r, i;
-+ struct pstore *ps = get_info(store);
-+ struct disk_exception de;
-+ struct commit_callback *cb;
-+
-+ de.old_chunk = e->old_chunk;
-+ de.new_chunk = e->new_chunk;
-+ write_exception(ps, ps->current_committed++, &de);
-+
-+ /*
-+ * Add the callback to the back of the array. This code
-+ * is the only place where the callback array is
-+ * manipulated, and we know that it will never be called
-+ * multiple times concurrently.
-+ */
-+ cb = ps->callbacks + ps->callback_count++;
-+ cb->callback = callback;
-+ cb->context = callback_context;
-+
-+ /*
-+ * If there are no more exceptions in flight, or we have
-+ * filled this metadata area we commit the exceptions to
-+ * disk.
-+ */
-+ if (atomic_dec_and_test(&ps->pending_count) ||
-+ (ps->current_committed == ps->exceptions_per_area)) {
-+ r = area_io(ps, ps->current_area, WRITE);
-+ if (r)
-+ ps->valid = 0;
-+
-+ for (i = 0; i < ps->callback_count; i++) {
-+ cb = ps->callbacks + i;
-+ cb->callback(cb->context, r == 0 ? 1 : 0);
-+ }
-+
-+ ps->callback_count = 0;
-+ }
-+
-+ /*
-+ * Have we completely filled the current area ?
-+ */
-+ if (ps->current_committed == ps->exceptions_per_area) {
-+ ps->current_committed = 0;
-+ r = zero_area(ps, ps->current_area + 1);
-+ if (r)
-+ ps->valid = 0;
-+ }
-+}
-+
-+static void persistent_drop(struct exception_store *store)
-+{
-+ struct pstore *ps = get_info(store);
-+
-+ ps->valid = 0;
-+ if (write_header(ps))
-+ DMWARN("write header failed");
-+}
-+
-+int dm_create_persistent(struct exception_store *store, uint32_t chunk_size)
-+{
-+ int r, new_snapshot;
-+ struct pstore *ps;
-+
-+ /* allocate the pstore */
-+ ps = kmalloc(sizeof(*ps), GFP_KERNEL);
-+ if (!ps)
-+ return -ENOMEM;
-+
-+ ps->snap = store->snap;
-+ ps->valid = 1;
-+ ps->version = SNAPSHOT_DISK_VERSION;
-+ ps->chunk_size = chunk_size;
-+ ps->exceptions_per_area = (chunk_size << SECTOR_SHIFT) /
-+ sizeof(struct disk_exception);
-+ ps->next_free = 2; /* skipping the header and first area */
-+ ps->current_committed = 0;
-+
-+ r = allocate_iobuf(ps);
-+ if (r)
-+ goto bad;
-+
-+ /*
-+ * Allocate space for all the callbacks.
-+ */
-+ ps->callback_count = 0;
-+ atomic_set(&ps->pending_count, 0);
-+ ps->callbacks = vmalloc(sizeof(*ps->callbacks) *
-+ ps->exceptions_per_area);
-+
-+ if (!ps->callbacks)
-+ goto bad;
-+
-+ /*
-+ * Read the snapshot header.
-+ */
-+ r = read_header(ps, &new_snapshot);
-+ if (r)
-+ goto bad;
-+
-+ /*
-+ * Do we need to setup a new snapshot ?
-+ */
-+ if (new_snapshot) {
-+ r = write_header(ps);
-+ if (r) {
-+ DMWARN("write_header failed");
-+ goto bad;
-+ }
-+
-+ r = zero_area(ps, 0);
-+ if (r) {
-+ DMWARN("zero_area(0) failed");
-+ goto bad;
-+ }
-+
-+ } else {
-+ /*
-+ * Sanity checks.
-+ */
-+ if (ps->chunk_size != chunk_size) {
-+ DMWARN("chunk size for existing snapshot different "
-+ "from that requested");
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ if (ps->version != SNAPSHOT_DISK_VERSION) {
-+ DMWARN("unable to handle snapshot disk version %d",
-+ ps->version);
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ /*
-+ * Read the metadata.
-+ */
-+ r = read_exceptions(ps);
-+ if (r)
-+ goto bad;
-+ }
-+
-+ store->destroy = persistent_destroy;
-+ store->prepare_exception = persistent_prepare;
-+ store->commit_exception = persistent_commit;
-+ store->drop_snapshot = persistent_drop;
-+ store->percent_full = persistent_percentfull;
-+ store->context = ps;
-+
-+ return r;
-+
-+ bad:
-+ if (ps) {
-+ if (ps->callbacks)
-+ vfree(ps->callbacks);
-+
-+ if (ps->iobuf)
-+ free_iobuf(ps);
-+
-+ kfree(ps);
-+ }
-+ return r;
-+}
-+
-+/*-----------------------------------------------------------------
-+ * Implementation of the store for non-persistent snapshots.
-+ *---------------------------------------------------------------*/
-+struct transient_c {
-+ offset_t next_free;
-+};
-+
-+void transient_destroy(struct exception_store *store)
-+{
-+ kfree(store->context);
-+}
-+
-+int transient_prepare(struct exception_store *store, struct exception *e)
-+{
-+ struct transient_c *tc = (struct transient_c *) store->context;
-+ offset_t size = get_dev_size(store->snap->cow->dev);
-+
-+ if (size < (tc->next_free + store->snap->chunk_size))
-+ return -1;
-+
-+ e->new_chunk = sector_to_chunk(store->snap, tc->next_free);
-+ tc->next_free += store->snap->chunk_size;
-+
-+ return 0;
-+}
-+
-+void transient_commit(struct exception_store *store,
-+ struct exception *e,
-+ void (*callback) (void *, int success),
-+ void *callback_context)
-+{
-+ /* Just succeed */
-+ callback(callback_context, 1);
-+}
-+
-+static int transient_percentfull(struct exception_store *store)
-+{
-+ struct transient_c *tc = (struct transient_c *) store->context;
-+ return (tc->next_free * 100) / get_dev_size(store->snap->cow->dev);
-+}
-+
-+int dm_create_transient(struct exception_store *store,
-+ struct dm_snapshot *s, int blocksize, void **error)
-+{
-+ struct transient_c *tc;
-+
-+ memset(store, 0, sizeof(*store));
-+ store->destroy = transient_destroy;
-+ store->prepare_exception = transient_prepare;
-+ store->commit_exception = transient_commit;
-+ store->percent_full = transient_percentfull;
-+ store->snap = s;
-+
-+ tc = kmalloc(sizeof(struct transient_c), GFP_KERNEL);
-+ if (!tc)
-+ return -ENOMEM;
-+
-+ tc->next_free = 0;
-+ store->context = tc;
-+
-+ return 0;
-+}
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-ioctl.c linux/drivers/md/dm-ioctl.c
---- linux-2.4.19-pre8/drivers/md/dm-ioctl.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-ioctl.c Mon May 20 14:27:13 2002
-@@ -0,0 +1,776 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+
-+#include <linux/miscdevice.h>
-+#include <linux/dm-ioctl.h>
-+#include <linux/init.h>
-+#include <linux/wait.h>
-+
-+static void free_params(struct dm_ioctl *param)
-+{
-+ vfree(param);
-+}
-+
-+static int version(struct dm_ioctl *user)
-+{
-+ return copy_to_user(user, DM_DRIVER_VERSION, sizeof(DM_DRIVER_VERSION));
-+}
-+
-+static int copy_params(struct dm_ioctl *user, struct dm_ioctl **param)
-+{
-+ struct dm_ioctl tmp, *dmi;
-+
-+ if (copy_from_user(&tmp, user, sizeof(tmp)))
-+ return -EFAULT;
-+
-+ if (strcmp(DM_IOCTL_VERSION, tmp.version)) {
-+ DMWARN("struct dm_ioctl version incompatible");
-+ return -EINVAL;
-+ }
-+
-+ if (tmp.data_size < sizeof(tmp))
-+ return -EINVAL;
-+
-+ dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
-+ if (!dmi)
-+ return -ENOMEM;
-+
-+ if (copy_from_user(dmi, user, tmp.data_size)) {
-+ vfree(dmi);
-+ return -EFAULT;
-+ }
-+
-+ *param = dmi;
-+ return 0;
-+}
-+
-+static int validate_params(uint cmd, struct dm_ioctl *param)
-+{
-+ /* Unless creating, either name of uuid but not both */
-+ if (cmd != DM_CREATE_CMD) {
-+ if ((!*param->uuid && !*param->name) ||
-+ (*param->uuid && *param->name)) {
-+ DMWARN("one of name or uuid must be supplied");
-+ return -EINVAL;
-+ }
-+ }
-+
-+ /* Ensure strings are terminated */
-+ param->name[DM_NAME_LEN - 1] = '\0';
-+ param->uuid[DM_UUID_LEN - 1] = '\0';
-+
-+ return 0;
-+}
-+
-+/*
-+ * Check a string doesn't overrun the chunk of
-+ * memory we copied from userland.
-+ */
-+static int valid_str(char *str, void *begin, void *end)
-+{
-+ while (((void *) str >= begin) && ((void *) str < end))
-+ if (!*str++)
-+ return 0;
-+
-+ return -EINVAL;
-+}
-+
-+static int next_target(struct dm_target_spec *last, unsigned long next,
-+ void *begin, void *end,
-+ struct dm_target_spec **spec, char **params)
-+{
-+ *spec = (struct dm_target_spec *)
-+ ((unsigned char *) last + next);
-+ *params = (char *) (*spec + 1);
-+
-+ if (*spec < (last + 1) || ((void *) *spec > end))
-+ return -EINVAL;
-+
-+ return valid_str(*params, begin, end);
-+}
-+
-+/*
-+ * Checks to see if there's a gap in the table.
-+ * Returns true iff there is a gap.
-+ */
-+static int gap(struct dm_table *table, struct dm_target_spec *spec)
-+{
-+ if (!table->num_targets)
-+ return (spec->sector_start > 0) ? 1 : 0;
-+
-+ if (spec->sector_start != table->highs[table->num_targets - 1] + 1)
-+ return 1;
-+
-+ return 0;
-+}
-+
-+static int populate_table(struct dm_table *table, struct dm_ioctl *args)
-+{
-+ int i = 0, r, first = 1, argc;
-+ struct dm_target_spec *spec;
-+ char *params, *argv[MAX_ARGS];
-+ struct target_type *ttype;
-+ void *context, *begin, *end;
-+ offset_t highs = 0;
-+
-+ if (!args->target_count) {
-+ DMWARN("populate_table: no targets specified");
-+ return -EINVAL;
-+ }
-+
-+ begin = (void *) args;
-+ end = begin + args->data_size;
-+
-+#define PARSE_ERROR(msg) {DMWARN(msg); return -EINVAL;}
-+
-+ for (i = 0; i < args->target_count; i++) {
-+
-+ r = first ? next_target((struct dm_target_spec *) args,
-+ args->data_start,
-+ begin, end, &spec, ¶ms) :
-+ next_target(spec, spec->next, begin, end, &spec, ¶ms);
-+
-+ if (r)
-+ PARSE_ERROR("unable to find target");
-+
-+ /* Look up the target type */
-+ ttype = dm_get_target_type(spec->target_type);
-+ if (!ttype)
-+ PARSE_ERROR("unable to find target type");
-+
-+ if (gap(table, spec))
-+ PARSE_ERROR("gap in target ranges");
-+
-+ /* Split up the parameter list */
-+ if (split_args(MAX_ARGS, &argc, argv, params) < 0)
-+ PARSE_ERROR("Too many arguments");
-+
-+ /* Build the target */
-+ if (ttype->ctr(table, spec->sector_start, spec->length,
-+ argc, argv, &context)) {
-+ DMWARN("%s: target constructor failed",
-+ (char *) context);
-+ return -EINVAL;
-+ }
-+
-+ /* Add the target to the table */
-+ highs = spec->sector_start + (spec->length - 1);
-+ if (dm_table_add_target(table, highs, ttype, context))
-+ PARSE_ERROR("internal error adding target to table");
-+
-+ first = 0;
-+ }
-+
-+#undef PARSE_ERROR
-+
-+ r = dm_table_complete(table);
-+ return r;
-+}
-+
-+/*
-+ * Round up the ptr to the next 'align' boundary. Obviously
-+ * 'align' must be a power of 2.
-+ */
-+static inline void *align_ptr(void *ptr, unsigned int align)
-+{
-+ align--;
-+ return (void *) (((unsigned long) (ptr + align)) & ~align);
-+}
-+
-+/*
-+ * Copies a dm_ioctl and an optional additional payload to
-+ * userland.
-+ */
-+static int results_to_user(struct dm_ioctl *user, struct dm_ioctl *param,
-+ void *data, unsigned long len)
-+{
-+ int r;
-+ void *ptr = NULL;
-+
-+ strncpy(param->version, DM_IOCTL_VERSION, sizeof(param->version));
-+
-+ if (data) {
-+ ptr = align_ptr(user + 1, sizeof(unsigned long));
-+ param->data_start = ptr - (void *) user;
-+ }
-+
-+ r = copy_to_user(user, param, sizeof(*param));
-+ if (r)
-+ return r;
-+
-+ if (data) {
-+ if (param->data_start + len > param->data_size)
-+ return -ENOSPC;
-+ r = copy_to_user(ptr, data, len);
-+ }
-+
-+ return r;
-+}
-+
-+/*
-+ * Fills in a dm_ioctl structure, ready for sending back to
-+ * userland.
-+ */
-+static void __info(struct mapped_device *md, struct dm_ioctl *param)
-+{
-+ param->flags = DM_EXISTS_FLAG;
-+ if (md->suspended)
-+ param->flags |= DM_SUSPEND_FLAG;
-+ if (md->read_only)
-+ param->flags |= DM_READONLY_FLAG;
-+
-+ strncpy(param->name, md->name, sizeof(param->name));
-+
-+ if (md->uuid)
-+ strncpy(param->uuid, md->uuid, sizeof(param->uuid) - 1);
-+ else
-+ param->uuid[0] = '\0';
-+
-+ param->open_count = md->use_count;
-+ param->dev = kdev_t_to_nr(md->dev);
-+ param->target_count = md->map->num_targets;
-+}
-+
-+/*
-+ * Always use UUID for lookups if it's present, otherwise use name.
-+ */
-+static inline char *lookup_name(struct dm_ioctl *param)
-+{
-+ return (*param->uuid) ? param->uuid : param->name;
-+}
-+
-+static inline int lookup_type(struct dm_ioctl *param)
-+{
-+ return (*param->uuid) ? DM_LOOKUP_BY_UUID : DM_LOOKUP_BY_NAME;
-+}
-+
-+#define ALIGNMENT sizeof(int)
-+static void *_align(void *ptr, unsigned int a)
-+{
-+ register unsigned long align = --a;
-+
-+ return (void *) (((unsigned long) ptr + align) & ~align);
-+}
-+
-+/*
-+ * Build up the status struct for each target
-+ */
-+static int __status(struct mapped_device *md, struct dm_ioctl *param,
-+ char *outbuf, int *len)
-+{
-+ int i;
-+ struct dm_target_spec *spec;
-+ unsigned long long sector = 0LL;
-+ char *outptr;
-+ status_type_t type;
-+
-+ if (param->flags & DM_STATUS_TABLE_FLAG)
-+ type = STATUSTYPE_TABLE;
-+ else
-+ type = STATUSTYPE_INFO;
-+
-+ outptr = outbuf;
-+
-+ /* Get all the target info */
-+ for (i = 0; i < md->map->num_targets; i++) {
-+ struct target_type *tt = md->map->targets[i].type;
-+ offset_t high = md->map->highs[i];
-+
-+ if (outptr - outbuf +
-+ sizeof(struct dm_target_spec) > param->data_size)
-+ return -ENOMEM;
-+
-+ spec = (struct dm_target_spec *) outptr;
-+
-+ spec->status = 0;
-+ spec->sector_start = sector;
-+ spec->length = high - sector + 1;
-+ strncpy(spec->target_type, tt->name, sizeof(spec->target_type));
-+
-+ outptr += sizeof(struct dm_target_spec);
-+
-+ /* Get the status/table string from the target driver */
-+ if (tt->status)
-+ tt->status(type, outptr,
-+ outbuf + param->data_size - outptr,
-+ md->map->targets[i].private);
-+ else
-+ outptr[0] = '\0';
-+
-+ outptr += strlen(outptr) + 1;
-+ _align(outptr, ALIGNMENT);
-+
-+ sector = high + 1;
-+
-+ spec->next = outptr - outbuf;
-+ }
-+
-+ param->target_count = md->map->num_targets;
-+ *len = outptr - outbuf;
-+
-+ return 0;
-+}
-+
-+static int __wait(struct mapped_device *md, struct dm_ioctl *param)
-+{
-+ int waiting = 0;
-+ int i;
-+ DECLARE_WAITQUEUE(waitq, current);
-+
-+ /* Get all the target info */
-+ for (i = 0; i < md->map->num_targets; i++) {
-+ struct target_type *tt = md->map->targets[i].type;
-+
-+ set_task_state(current, TASK_INTERRUPTIBLE);
-+
-+ /* Add ourself to the target's wait queue */
-+ if (tt->wait &&
-+ (!tt->wait(md->map->targets[i].private, &waitq, 1)))
-+ waiting = 1;
-+ }
-+
-+ /* If at least one call succeeded then sleep */
-+ if (waiting) {
-+ schedule();
-+
-+ for (i = 0; i < md->map->num_targets; i++) {
-+ struct target_type *tt = md->map->targets[i].type;
-+
-+ /* And remove ourself */
-+ if (tt->wait)
-+ tt->wait(md->map->targets[i].private,
-+ &waitq, 0);
-+ }
-+ }
-+
-+ set_task_state(current, TASK_RUNNING);
-+
-+ return 0;
-+}
-+
-+/*
-+ * Return the status of a device as a text string for each
-+ * target.
-+ */
-+static int get_status(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ struct mapped_device *md;
-+ int len = 0;
-+ int ret;
-+ char *outbuf = NULL;
-+
-+ md = dm_get_name_r(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ /*
-+ * Device not found - returns cleared exists flag.
-+ */
-+ goto out;
-+
-+ /* We haven't a clue how long the resultant data will be so
-+ just allocate as much as userland has allowed us and make sure
-+ we don't overun it */
-+ outbuf = kmalloc(param->data_size, GFP_KERNEL);
-+ if (!outbuf)
-+ goto out;
-+ /*
-+ * Get the status of all targets
-+ */
-+ __status(md, param, outbuf, &len);
-+
-+ /*
-+ * Setup the basic dm_ioctl structure.
-+ */
-+ __info(md, param);
-+
-+ out:
-+ if (md)
-+ dm_put_r(md);
-+
-+ ret = results_to_user(user, param, outbuf, len);
-+
-+ if (outbuf)
-+ kfree(outbuf);
-+
-+ return ret;
-+}
-+
-+/*
-+ * Wait for a device to report an event
-+ */
-+static int wait_device_event(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ struct mapped_device *md;
-+
-+ md = dm_get_name_r(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ /*
-+ * Device not found - returns cleared exists flag.
-+ */
-+ goto out;
-+ /*
-+ * Setup the basic dm_ioctl structure.
-+ */
-+ __info(md, param);
-+
-+ /*
-+ * Wait for anotification event
-+ */
-+ __wait(md, param);
-+
-+ dm_put_r(md);
-+
-+ out:
-+ return results_to_user(user, param, NULL, 0);
-+}
-+
-+/*
-+ * Copies device info back to user space, used by
-+ * the create and info ioctls.
-+ */
-+static int info(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ struct mapped_device *md;
-+
-+ param->flags = 0;
-+
-+ md = dm_get_name_r(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ /*
-+ * Device not found - returns cleared exists flag.
-+ */
-+ goto out;
-+
-+ __info(md, param);
-+ dm_put_r(md);
-+
-+ out:
-+ return results_to_user(user, param, NULL, 0);
-+}
-+
-+/*
-+ * Retrieves a list of devices used by a particular dm device.
-+ */
-+static int dep(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ int count, r;
-+ struct mapped_device *md;
-+ struct list_head *tmp;
-+ size_t len = 0;
-+ struct dm_target_deps *deps = NULL;
-+
-+ md = dm_get_name_r(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ goto out;
-+
-+ /*
-+ * Setup the basic dm_ioctl structure.
-+ */
-+ __info(md, param);
-+
-+ /*
-+ * Count the devices.
-+ */
-+ count = 0;
-+ list_for_each(tmp, &md->map->devices)
-+ count++;
-+
-+ /*
-+ * Allocate a kernel space version of the dm_target_status
-+ * struct.
-+ */
-+ len = sizeof(*deps) + (sizeof(*deps->dev) * count);
-+ deps = kmalloc(len, GFP_KERNEL);
-+ if (!deps) {
-+ dm_put_r(md);
-+ return -ENOMEM;
-+ }
-+
-+ /*
-+ * Fill in the devices.
-+ */
-+ deps->count = count;
-+ count = 0;
-+ list_for_each(tmp, &md->map->devices) {
-+ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
-+ deps->dev[count++] = kdev_t_to_nr(dd->dev);
-+ }
-+ dm_put_r(md);
-+
-+ out:
-+ r = results_to_user(user, param, deps, len);
-+
-+ kfree(deps);
-+ return r;
-+}
-+
-+static int create(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ int r, ro;
-+ struct dm_table *t;
-+ int minor;
-+
-+ r = dm_table_create(&t);
-+ if (r)
-+ return r;
-+
-+ r = populate_table(t, param);
-+ if (r) {
-+ dm_table_destroy(t);
-+ return r;
-+ }
-+
-+ minor = (param->flags & DM_PERSISTENT_DEV_FLAG) ?
-+ MINOR(to_kdev_t(param->dev)) : -1;
-+
-+ ro = (param->flags & DM_READONLY_FLAG) ? 1 : 0;
-+
-+ r = dm_create(param->name, param->uuid, minor, ro, t);
-+ if (r) {
-+ dm_table_destroy(t);
-+ return r;
-+ }
-+
-+ r = info(param, user);
-+ return r;
-+}
-+
-+static int remove(struct dm_ioctl *param)
-+{
-+ int r;
-+ struct mapped_device *md;
-+
-+ md = dm_get_name_w(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ return -ENXIO;
-+
-+ r = dm_destroy(md);
-+ dm_put_w(md);
-+ if (!r)
-+ kfree(md);
-+
-+ return r;
-+}
-+
-+static int suspend(struct dm_ioctl *param)
-+{
-+ int r;
-+ struct mapped_device *md;
-+
-+ md = dm_get_name_w(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ return -ENXIO;
-+
-+ r = (param->flags & DM_SUSPEND_FLAG) ? dm_suspend(md) : dm_resume(md);
-+ dm_put_w(md);
-+
-+ return r;
-+}
-+
-+static int reload(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ int r;
-+ struct mapped_device *md;
-+ struct dm_table *t;
-+
-+ r = dm_table_create(&t);
-+ if (r)
-+ return r;
-+
-+ r = populate_table(t, param);
-+ if (r) {
-+ dm_table_destroy(t);
-+ return r;
-+ }
-+
-+ md = dm_get_name_w(lookup_name(param), lookup_type(param));
-+ if (!md) {
-+ dm_table_destroy(t);
-+ return -ENXIO;
-+ }
-+
-+ r = dm_swap_table(md, t);
-+ if (r) {
-+ dm_put_w(md);
-+ dm_table_destroy(t);
-+ return r;
-+ }
-+
-+ dm_set_ro(md, (param->flags & DM_READONLY_FLAG) ? 1 : 0);
-+ dm_put_w(md);
-+
-+ r = info(param, user);
-+ return r;
-+}
-+
-+static int rename(struct dm_ioctl *param)
-+{
-+ char *newname = (char *) param + param->data_start;
-+
-+ if (valid_str(newname, (void *) param,
-+ (void *) param + param->data_size) ||
-+ dm_set_name(lookup_name(param), lookup_type(param), newname)) {
-+ DMWARN("Invalid new logical volume name supplied.");
-+ return -EINVAL;
-+ }
-+
-+ return 0;
-+}
-+
-+static int ctl_open(struct inode *inode, struct file *file)
-+{
-+ /* only root can open this */
-+ if (!capable(CAP_SYS_ADMIN))
-+ return -EACCES;
-+
-+ MOD_INC_USE_COUNT;
-+
-+ return 0;
-+}
-+
-+static int ctl_close(struct inode *inode, struct file *file)
-+{
-+ MOD_DEC_USE_COUNT;
-+ return 0;
-+}
-+
-+static int ctl_ioctl(struct inode *inode, struct file *file,
-+ uint command, ulong u)
-+{
-+ int r = 0;
-+ struct dm_ioctl *param;
-+ struct dm_ioctl *user = (struct dm_ioctl *) u;
-+ uint cmd = _IOC_NR(command);
-+
-+ /* Process commands without params first - always return version */
-+ switch (cmd) {
-+ case DM_REMOVE_ALL_CMD:
-+ dm_destroy_all();
-+ case DM_VERSION_CMD:
-+ return version(user);
-+ default:
-+ break;
-+ }
-+
-+ r = copy_params(user, ¶m);
-+ if (r)
-+ goto err;
-+
-+ r = validate_params(cmd, param);
-+ if (r) {
-+ free_params(param);
-+ goto err;
-+ }
-+
-+ switch (cmd) {
-+ case DM_INFO_CMD:
-+ r = info(param, user);
-+ break;
-+
-+ case DM_SUSPEND_CMD:
-+ r = suspend(param);
-+ break;
-+
-+ case DM_CREATE_CMD:
-+ r = create(param, user);
-+ break;
-+
-+ case DM_RELOAD_CMD:
-+ r = reload(param, user);
-+ break;
-+
-+ case DM_REMOVE_CMD:
-+ r = remove(param);
-+ break;
-+
-+ case DM_RENAME_CMD:
-+ r = rename(param);
-+ break;
-+
-+ case DM_DEPS_CMD:
-+ r = dep(param, user);
-+ break;
-+
-+ case DM_GET_STATUS_CMD:
-+ r = get_status(param, user);
-+ break;
-+
-+ case DM_WAIT_EVENT_CMD:
-+ r = wait_device_event(param, user);
-+ break;
-+
-+ default:
-+ DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
-+ r = -EINVAL;
-+ }
-+
-+ free_params(param);
-+ return r;
-+
-+ err:
-+ version(user);
-+ return r;
-+}
-+
-+static struct file_operations _ctl_fops = {
-+ open: ctl_open,
-+ release:ctl_close,
-+ ioctl: ctl_ioctl,
-+ owner: THIS_MODULE,
-+};
-+
-+static devfs_handle_t _ctl_handle;
-+
-+static struct miscdevice _dm_misc = {
-+ minor: MISC_DYNAMIC_MINOR,
-+ name: DM_NAME,
-+ fops: &_ctl_fops
-+};
-+
-+/* Create misc character device and link to DM_DIR/control */
-+int __init dm_interface_init(void)
-+{
-+ int r;
-+ char rname[64];
-+
-+ r = misc_register(&_dm_misc);
-+ if (r) {
-+ DMERR("misc_register failed for control device");
-+ return r;
-+ }
-+
-+ r = devfs_generate_path(_dm_misc.devfs_handle, rname + 3,
-+ sizeof rname - 3);
-+ if (r == -ENOSYS)
-+ return 0; /* devfs not present */
-+
-+ if (r < 0) {
-+ DMERR("devfs_generate_path failed for control device");
-+ goto failed;
-+ }
-+
-+ strncpy(rname + r, "../", 3);
-+ r = devfs_mk_symlink(NULL, DM_DIR "/control",
-+ DEVFS_FL_DEFAULT, rname + r, &_ctl_handle, NULL);
-+ if (r) {
-+ DMERR("devfs_mk_symlink failed for control device");
-+ goto failed;
-+ }
-+ devfs_auto_unregister(_dm_misc.devfs_handle, _ctl_handle);
-+
-+ return 0;
-+
-+ failed:
-+ misc_deregister(&_dm_misc);
-+ return r;
-+}
-+
-+void dm_interface_exit(void)
-+{
-+ if (misc_deregister(&_dm_misc) < 0)
-+ DMERR("misc_deregister failed for control device");
-+}
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-linear.c linux/drivers/md/dm-linear.c
---- linux-2.4.19-pre8/drivers/md/dm-linear.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-linear.c Mon May 20 14:23:20 2002
-@@ -0,0 +1,126 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+
-+#include <linux/module.h>
-+#include <linux/init.h>
-+#include <linux/blkdev.h>
-+
-+/*
-+ * Linear: maps a linear range of a device.
-+ */
-+struct linear_c {
-+ long delta; /* FIXME: we need a signed offset type */
-+ long start; /* For display only */
-+ struct dm_dev *dev;
-+};
-+
-+/*
-+ * Construct a linear mapping: <dev_path> <offset>
-+ */
-+static int linear_ctr(struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **argv, void **context)
-+{
-+ struct linear_c *lc;
-+ unsigned long start; /* FIXME: unsigned long long */
-+ char *end;
-+
-+ if (argc != 2) {
-+ *context = "dm-linear: Not enough arguments";
-+ return -EINVAL;
-+ }
-+
-+ lc = kmalloc(sizeof(*lc), GFP_KERNEL);
-+ if (lc == NULL) {
-+ *context = "dm-linear: Cannot allocate linear context";
-+ return -ENOMEM;
-+ }
-+
-+ start = simple_strtoul(argv[1], &end, 10);
-+ if (*end) {
-+ *context = "dm-linear: Invalid device sector";
-+ goto bad;
-+ }
-+
-+ if (dm_table_get_device(t, argv[0], start, l, &lc->dev)) {
-+ *context = "dm-linear: Device lookup failed";
-+ goto bad;
-+ }
-+
-+ lc->delta = (int) start - (int) b;
-+ lc->start = start;
-+ *context = lc;
-+ return 0;
-+
-+ bad:
-+ kfree(lc);
-+ return -EINVAL;
-+}
-+
-+static void linear_dtr(struct dm_table *t, void *c)
-+{
-+ struct linear_c *lc = (struct linear_c *) c;
-+
-+ dm_table_put_device(t, lc->dev);
-+ kfree(c);
-+}
-+
-+static int linear_map(struct buffer_head *bh, int rw, void *context)
-+{
-+ struct linear_c *lc = (struct linear_c *) context;
-+
-+ bh->b_rdev = lc->dev->dev;
-+ bh->b_rsector = bh->b_rsector + lc->delta;
-+
-+ return 1;
-+}
-+
-+static int linear_status(status_type_t type, char *result, int maxlen,
-+ void *context)
-+{
-+ struct linear_c *lc = (struct linear_c *) context;
-+
-+ switch (type) {
-+ case STATUSTYPE_INFO:
-+ result[0] = '\0';
-+ break;
-+
-+ case STATUSTYPE_TABLE:
-+ snprintf(result, maxlen, "%s %ld", kdevname(lc->dev->dev),
-+ lc->start);
-+ break;
-+ }
-+ return 0;
-+}
-+
-+static struct target_type linear_target = {
-+ name: "linear",
-+ module: THIS_MODULE,
-+ ctr: linear_ctr,
-+ dtr: linear_dtr,
-+ map: linear_map,
-+ status: linear_status,
-+ wait: NULL, /* No wait function */
-+};
-+
-+int __init dm_linear_init(void)
-+{
-+ int r = dm_register_target(&linear_target);
-+
-+ if (r < 0)
-+ DMERR("linear: register failed %d", r);
-+
-+ return r;
-+}
-+
-+void dm_linear_exit(void)
-+{
-+ int r = dm_unregister_target(&linear_target);
-+
-+ if (r < 0)
-+ DMERR("linear: unregister failed %d", r);
-+}
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-mirror.c linux/drivers/md/dm-mirror.c
---- linux-2.4.19-pre8/drivers/md/dm-mirror.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-mirror.c Fri May 10 15:40:22 2002
-@@ -0,0 +1,344 @@
-+/*
-+ * Copyright (C) 2002 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+#include "kcopyd.h"
-+
-+#include <linux/module.h>
-+#include <linux/init.h>
-+#include <linux/blkdev.h>
-+
-+/* kcopyd priority of mirror operations */
-+#define MIRROR_COPY_PRIORITY 5
-+
-+static kmem_cache_t *bh_cachep;
-+
-+/*
-+ * Mirror: maps a mirror range of a device.
-+ */
-+struct mirror_c {
-+ struct dm_dev *fromdev;
-+ struct dm_dev *todev;
-+
-+ unsigned long from_delta;
-+ unsigned long to_delta;
-+
-+ unsigned long frompos;
-+ unsigned long topos;
-+
-+ unsigned long got_to;
-+ unsigned long size; /* for %age calculation */
-+ struct rw_semaphore lock;
-+ struct buffer_head *bhstring;
-+ wait_queue_head_t waitq;
-+ int error;
-+};
-+
-+/* Called when a duplicating I/O has finished */
-+static void mirror_end_io(struct buffer_head *bh, int uptodate)
-+{
-+ struct mirror_c *lc = (struct mirror_c *) bh->b_private;
-+
-+ /* Flag error if it failed */
-+ if (!uptodate) {
-+ DMERR("Mirror copy to %s failed", kdevname(lc->todev->dev));
-+ lc->error = 1;
-+ wake_up_interruptible(&lc->waitq);
-+ }
-+ kmem_cache_free(bh_cachep, bh);
-+ wake_up_interruptible(&lc->waitq);
-+}
-+
-+static void mirror_bh(struct mirror_c *mc, struct buffer_head *bh)
-+{
-+ struct buffer_head *dbh = kmem_cache_alloc(bh_cachep, GFP_NOIO);
-+ if (dbh) {
-+ *dbh = *bh;
-+ dbh->b_rdev = mc->todev->dev;
-+ dbh->b_rsector = bh->b_rsector - mc->from_delta + mc->to_delta;
-+ dbh->b_end_io = mirror_end_io;
-+ dbh->b_private = mc;
-+
-+ generic_make_request(WRITE, dbh);
-+ } else {
-+ DMERR("kmem_cache_alloc failed for mirror bh");
-+ mc->error = 1;
-+ }
-+}
-+
-+/* Called when the copy I/O has finished */
-+static void copy_callback(copy_cb_reason_t reason, void *context, long arg)
-+{
-+ struct mirror_c *lc = (struct mirror_c *) context;
-+ struct buffer_head *bh;
-+
-+ if (reason == COPY_CB_FAILED_READ || reason == COPY_CB_FAILED_WRITE) {
-+ DMERR("Mirror block %s on %s failed, sector %ld",
-+ reason == COPY_CB_FAILED_READ ? "read" : "write",
-+ reason == COPY_CB_FAILED_READ ?
-+ kdevname(lc->fromdev->dev) :
-+ kdevname(lc->todev->dev), arg);
-+ lc->error = 1;
-+ return;
-+ }
-+
-+ if (reason == COPY_CB_COMPLETE) {
-+ /* Say we've finished */
-+ dm_notify(lc); /* TODO: interface ?? */
-+ }
-+
-+ if (reason == COPY_CB_PROGRESS) {
-+ dm_notify(lc); /* TODO: interface ?? */
-+ }
-+
-+ /* Submit, and mirror any pending BHs */
-+ down_write(&lc->lock);
-+ lc->got_to = arg;
-+
-+ bh = lc->bhstring;
-+ lc->bhstring = NULL;
-+ up_write(&lc->lock);
-+
-+ while (bh) {
-+ struct buffer_head *nextbh = bh->b_reqnext;
-+ bh->b_reqnext = NULL;
-+ generic_make_request(WRITE, bh);
-+ mirror_bh(lc, bh);
-+ bh = nextbh;
-+ }
-+}
-+
-+/*
-+ * Construct a mirror mapping: <dev_path1> <offset> <dev_path2> <offset> <throttle> [<priority>]
-+ */
-+static int mirror_ctr(struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **argv, void **context)
-+{
-+ struct mirror_c *lc;
-+ unsigned long offset1, offset2;
-+ char *value;
-+ int priority = MIRROR_COPY_PRIORITY;
-+ int throttle;
-+ struct kcopyd_region src, dest;
-+
-+ if (argc <= 4) {
-+ *context = "dm-mirror: Not enough arguments";
-+ return -EINVAL;
-+ }
-+
-+ lc = kmalloc(sizeof(*lc), GFP_KERNEL);
-+ if (lc == NULL) {
-+ *context = "dm-mirror: Cannot allocate mirror context";
-+ return -ENOMEM;
-+ }
-+
-+ if (dm_table_get_device(t, argv[0], 0, l, &lc->fromdev)) {
-+ *context = "dm-mirror: Device lookup failed";
-+ goto bad;
-+ }
-+
-+ offset1 = simple_strtoul(argv[1], &value, 10);
-+ if (value == NULL) {
-+ *context = "Invalid offset for dev1";
-+ dm_table_put_device(t, lc->fromdev);
-+ goto bad;
-+ }
-+
-+ if (dm_table_get_device(t, argv[2], 0, l, &lc->todev)) {
-+ *context = "dm-mirror: Device lookup failed";
-+ dm_table_put_device(t, lc->fromdev);
-+ goto bad;
-+ }
-+
-+ offset2 = simple_strtoul(argv[3], &value, 10);
-+ if (value == NULL) {
-+ *context = "Invalid offset for dev2";
-+ goto bad_put;
-+ }
-+
-+ throttle = simple_strtoul(argv[4], &value, 10);
-+ if (value == NULL) {
-+ *context = "Invalid throttle value";
-+ goto bad_put;
-+ }
-+
-+ if (argc > 5) {
-+ priority = simple_strtoul(argv[5], &value, 10);
-+ if (value == NULL) {
-+ *context = "Invalid priority value";
-+ goto bad_put;
-+ }
-+ }
-+
-+ lc->from_delta = (int) offset1 - (int) b;
-+ lc->to_delta = (int) offset2 - (int) b;
-+ lc->frompos = offset1;
-+ lc->topos = offset2;
-+ lc->error = 0;
-+ lc->bhstring = NULL;
-+ lc->size = l - offset1;
-+ init_waitqueue_head(&lc->waitq);
-+ init_rwsem(&lc->lock);
-+ *context = lc;
-+
-+ /* Tell kcopyd to do the biz */
-+ src.dev = lc->fromdev->dev;
-+ src.sector = offset1;
-+ src.count = l - offset1;
-+
-+ dest.dev = lc->todev->dev;
-+ dest.sector = offset2;
-+ dest.count = l - offset1;
-+
-+ if (kcopyd_copy(&src, &dest, priority, 0, copy_callback, lc)) {
-+ DMERR("block copy call failed");
-+ dm_table_put_device(t, lc->fromdev);
-+ dm_table_put_device(t, lc->todev);
-+ goto bad;
-+ }
-+ return 0;
-+
-+ bad_put:
-+ dm_table_put_device(t, lc->fromdev);
-+ dm_table_put_device(t, lc->todev);
-+ bad:
-+ kfree(lc);
-+ return -EINVAL;
-+}
-+
-+static void mirror_dtr(struct dm_table *t, void *c)
-+{
-+ struct mirror_c *lc = (struct mirror_c *) c;
-+
-+ /* Just in case anyone is still waiting... */
-+ wake_up_interruptible(&lc->waitq);
-+
-+ dm_table_put_device(t, lc->fromdev);
-+ dm_table_put_device(t, lc->todev);
-+ kfree(c);
-+}
-+
-+static int mirror_map(struct buffer_head *bh, int rw, void *context)
-+{
-+ struct mirror_c *lc = (struct mirror_c *) context;
-+
-+ bh->b_rdev = lc->fromdev->dev;
-+ bh->b_rsector = bh->b_rsector + lc->from_delta;
-+
-+ if (rw == WRITE) {
-+ down_write(&lc->lock);
-+
-+ /*
-+ * If this area is in flight then save it until it's
-+ * commited to the mirror disk and then submit it and
-+ * its mirror.
-+ */
-+ if (bh->b_rsector > lc->got_to &&
-+ bh->b_rsector <= lc->got_to + KIO_MAX_SECTORS) {
-+ bh->b_reqnext = lc->bhstring;
-+ lc->bhstring = bh;
-+ up_write(&lc->lock);
-+ return 0;
-+ }
-+
-+ /*
-+ * If we've already copied this block then duplicate
-+ * it to the mirror device
-+ */
-+ if (bh->b_rsector < lc->got_to) {
-+ /* Schedule copy of I/O to other target */
-+ mirror_bh(lc, bh);
-+ }
-+ up_write(&lc->lock);
-+ }
-+ return 1;
-+}
-+
-+static int mirror_sts(status_type_t sts_type, char *result, int maxlen,
-+ void *context)
-+{
-+ struct mirror_c *mc = (struct mirror_c *) context;
-+
-+ switch (sts_type) {
-+ case STATUSTYPE_INFO:
-+ if (mc->error)
-+ snprintf(result, maxlen, "Error");
-+ else
-+ snprintf(result, maxlen, "%ld%%",
-+ (mc->got_to -
-+ mc->from_delta) * 100 / mc->size);
-+ break;
-+
-+ case STATUSTYPE_TABLE:
-+ snprintf(result, maxlen, "%s %ld %s %ld %d",
-+ kdevname(mc->fromdev->dev), mc->frompos,
-+ kdevname(mc->todev->dev), mc->topos, 0);
-+ break;
-+ }
-+ return 0;
-+}
-+
-+static int mirror_wait(wait_queue_t *wq, void *context)
-+{
-+ struct mirror_c *mc = (struct mirror_c *) context;
-+
-+ if (add)
-+ add_wait_queue(&mc->waitq, wq);
-+ else
-+ remove_wait_queue(&mc->waitq, wq);
-+
-+ return 0;
-+}
-+
-+static struct target_type mirror_target = {
-+ name: "mirror",
-+ module: THIS_MODULE,
-+ ctr: mirror_ctr,
-+ dtr: mirror_dtr,
-+ map: mirror_map,
-+ sts: mirror_sts,
-+ wait: mirror_wait,
-+};
-+
-+int __init dm_mirror_init(void)
-+{
-+ int r;
-+
-+ bh_cachep = kmem_cache_create("dm-mirror",
-+ sizeof(struct buffer_head),
-+ __alignof__(struct buffer_head),
-+ 0, NULL, NULL);
-+ if (!bh_cachep)
-+ return -1;
-+
-+ r = dm_register_target(&mirror_target);
-+ if (r < 0) {
-+ DMERR("mirror: register failed %d", r);
-+ kmem_cache_destroy(bh_cachep);
-+ }
-+ return r;
-+}
-+
-+void dm_mirror_exit(void)
-+{
-+ int r = dm_unregister_target(&mirror_target);
-+
-+ if (r < 0)
-+ DMERR("mirror: unregister failed %d", r);
-+
-+ kmem_cache_destroy(bh_cachep);
-+}
-+
-+/*
-+ * Overrides for Emacs so that we follow Linus's tabbing style.
-+ * Emacs will notice this stuff at the end of the file and automatically
-+ * adjust the settings for this buffer only. This must remain at the end
-+ * of the file.
-+ * ---------------------------------------------------------------------------
-+ * Local variables:
-+ * c-file-style: "linux"
-+ * End:
-+ */
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-snapshot.c linux/drivers/md/dm-snapshot.c
---- linux-2.4.19-pre8/drivers/md/dm-snapshot.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-snapshot.c Mon May 20 14:25:58 2002
-@@ -0,0 +1,1208 @@
-+/*
-+ * dm-snapshot.c
-+ *
-+ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include <linux/config.h>
-+#include <linux/module.h>
-+#include <linux/init.h>
-+#include <linux/slab.h>
-+#include <linux/list.h>
-+#include <linux/fs.h>
-+#include <linux/blkdev.h>
-+#include <linux/mempool.h>
-+#include <linux/device-mapper.h>
-+
-+#include "dm-snapshot.h"
-+#include "kcopyd.h"
-+
-+/*
-+ * FIXME: Remove this before release.
-+ */
-+#if 0
-+#define DMDEBUG(x...) DMWARN( ## x)
-+#else
-+#define DMDEBUG(x...)
-+#endif
-+
-+/*
-+ * The percentage increment we will wake up users at
-+ */
-+#define WAKE_UP_PERCENT 5
-+
-+/*
-+ * Hard sector size used all over the kernel
-+ */
-+#define SECTOR_SIZE 512
-+
-+/*
-+ * kcopyd priority of snapshot operations
-+ */
-+#define SNAPSHOT_COPY_PRIORITY 2
-+
-+struct pending_exception {
-+ struct exception e;
-+
-+ /*
-+ * Origin buffers waiting for this to complete are held
-+ * in a list (using b_reqnext).
-+ */
-+ struct buffer_head *origin_bhs;
-+ struct buffer_head *snapshot_bhs;
-+
-+ /*
-+ * Other pending_exceptions that are processing this
-+ * chunk. When this list is empty, we know we can
-+ * complete the origins.
-+ */
-+ struct list_head siblings;
-+
-+ /* Pointer back to snapshot context */
-+ struct dm_snapshot *snap;
-+
-+ /*
-+ * 1 indicates the exception has already been sent to
-+ * kcopyd.
-+ */
-+ int started;
-+};
-+
-+/*
-+ * Hash table mapping origin volumes to lists of snapshots and
-+ * a lock to protect it
-+ */
-+static kmem_cache_t *exception_cache;
-+static kmem_cache_t *pending_cache;
-+static mempool_t *pending_pool;
-+
-+/*
-+ * One of these per registered origin, held in the snapshot_origins hash
-+ */
-+struct origin {
-+ /* The origin device */
-+ kdev_t dev;
-+
-+ struct list_head hash_list;
-+
-+ /* List of snapshots for this origin */
-+ struct list_head snapshots;
-+};
-+
-+/*
-+ * Useful macro for running the store functions. Use
-+ * store_int_fn if you want the return value.
-+ */
-+#define store_fn(snap, fn, args...) \
-+ if ((snap)->store. ## fn) \
-+ (snap)->store. ## fn ( &(snap)->store , ## args )
-+
-+#define store_int_fn(snap, fn, args...) \
-+ (((snap)->store. ## fn) ? \
-+ ((snap)->store. ## fn ( &(snap)->store , ## args )) : 0)
-+
-+/*
-+ * Size of the hash table for origin volumes. If we make this
-+ * the size of the minors list then it should be nearly perfect
-+ */
-+#define ORIGIN_HASH_SIZE 256
-+#define ORIGIN_MASK 0xFF
-+static struct list_head *_origins;
-+static struct rw_semaphore _origins_lock;
-+
-+static int init_origin_hash(void)
-+{
-+ int i;
-+
-+ _origins = kmalloc(ORIGIN_HASH_SIZE * sizeof(struct list_head),
-+ GFP_KERNEL);
-+ if (!_origins) {
-+ DMERR("Device mapper: Snapshot: unable to allocate memory");
-+ return -ENOMEM;
-+ }
-+
-+ for (i = 0; i < ORIGIN_HASH_SIZE; i++)
-+ INIT_LIST_HEAD(_origins + i);
-+ init_rwsem(&_origins_lock);
-+
-+ return 0;
-+}
-+
-+static void exit_origin_hash(void)
-+{
-+ kfree(_origins);
-+}
-+
-+static inline unsigned int origin_hash(kdev_t dev)
-+{
-+ return MINOR(dev) & ORIGIN_MASK;
-+}
-+
-+static struct origin *__lookup_origin(kdev_t origin)
-+{
-+ struct list_head *slist;
-+ struct list_head *ol;
-+ struct origin *o;
-+
-+ ol = &_origins[origin_hash(origin)];
-+ list_for_each(slist, ol) {
-+ o = list_entry(slist, struct origin, hash_list);
-+
-+ if (o->dev == origin)
-+ return o;
-+ }
-+
-+ return NULL;
-+}
-+
-+static void __insert_origin(struct origin *o)
-+{
-+ struct list_head *sl = &_origins[origin_hash(o->dev)];
-+ list_add_tail(&o->hash_list, sl);
-+}
-+
-+/*
-+ * Make a note of the snapshot and its origin so we can look it
-+ * up when the origin has a write on it.
-+ */
-+static int register_snapshot(struct dm_snapshot *snap)
-+{
-+ struct origin *o;
-+ kdev_t dev = snap->origin->dev;
-+
-+ down_write(&_origins_lock);
-+ o = __lookup_origin(dev);
-+
-+ if (!o) {
-+ /* New origin */
-+ o = kmalloc(sizeof(*o), GFP_KERNEL);
-+ if (!o) {
-+ up_write(&_origins_lock);
-+ return -ENOMEM;
-+ }
-+
-+ /* Initialise the struct */
-+ INIT_LIST_HEAD(&o->snapshots);
-+ o->dev = dev;
-+
-+ __insert_origin(o);
-+ }
-+
-+ list_add_tail(&snap->list, &o->snapshots);
-+
-+ up_write(&_origins_lock);
-+ return 0;
-+}
-+
-+static void unregister_snapshot(struct dm_snapshot *s)
-+{
-+ struct origin *o;
-+
-+ down_write(&_origins_lock);
-+ o = __lookup_origin(s->origin->dev);
-+
-+ list_del(&s->list);
-+ if (list_empty(&o->snapshots)) {
-+ list_del(&o->hash_list);
-+ kfree(o);
-+ }
-+
-+ up_write(&_origins_lock);
-+}
-+
-+/*
-+ * Implementation of the exception hash tables.
-+ */
-+static int init_exception_table(struct exception_table *et, uint32_t size)
-+{
-+ int i;
-+
-+ et->hash_mask = size - 1;
-+ et->table = vmalloc(sizeof(struct list_head) * (size));
-+ if (!et->table)
-+ return -ENOMEM;
-+
-+ for (i = 0; i < size; i++)
-+ INIT_LIST_HEAD(et->table + i);
-+
-+ return 0;
-+}
-+
-+static void exit_exception_table(struct exception_table *et, kmem_cache_t *mem)
-+{
-+ struct list_head *slot, *entry, *temp;
-+ struct exception *ex;
-+ int i, size;
-+
-+ size = et->hash_mask + 1;
-+ for (i = 0; i < size; i++) {
-+ slot = et->table + i;
-+
-+ list_for_each_safe(entry, temp, slot) {
-+ ex = list_entry(entry, struct exception, hash_list);
-+ kmem_cache_free(mem, ex);
-+ }
-+ }
-+
-+ vfree(et->table);
-+}
-+
-+/*
-+ * FIXME: check how this hash fn is performing.
-+ */
-+static inline uint32_t exception_hash(struct exception_table *et, chunk_t chunk)
-+{
-+ return chunk & et->hash_mask;
-+}
-+
-+static void insert_exception(struct exception_table *eh, struct exception *e)
-+{
-+ struct list_head *l = &eh->table[exception_hash(eh, e->old_chunk)];
-+ list_add(&e->hash_list, l);
-+}
-+
-+static inline void remove_exception(struct exception *e)
-+{
-+ list_del(&e->hash_list);
-+}
-+
-+/*
-+ * Return the exception data for a sector, or NULL if not
-+ * remapped.
-+ */
-+static struct exception *lookup_exception(struct exception_table *et,
-+ chunk_t chunk)
-+{
-+ struct list_head *slot, *el;
-+ struct exception *e;
-+
-+ slot = &et->table[exception_hash(et, chunk)];
-+ list_for_each(el, slot) {
-+ e = list_entry(el, struct exception, hash_list);
-+ if (e->old_chunk == chunk)
-+ return e;
-+ }
-+
-+ return NULL;
-+}
-+
-+static inline struct exception *alloc_exception(void)
-+{
-+ struct exception *e;
-+
-+ e = kmem_cache_alloc(exception_cache, GFP_NOIO);
-+ if (!e)
-+ e = kmem_cache_alloc(exception_cache, GFP_ATOMIC);
-+
-+ return e;
-+}
-+
-+static inline void free_exception(struct exception *e)
-+{
-+ kmem_cache_free(exception_cache, e);
-+}
-+
-+static inline struct pending_exception *alloc_pending_exception(void)
-+{
-+ return mempool_alloc(pending_pool, GFP_NOIO);
-+}
-+
-+static inline void free_pending_exception(struct pending_exception *pe)
-+{
-+ mempool_free(pe, pending_pool);
-+}
-+
-+int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new)
-+{
-+ struct exception *e;
-+
-+ e = alloc_exception();
-+ if (!e)
-+ return -ENOMEM;
-+
-+ e->old_chunk = old;
-+ e->new_chunk = new;
-+ insert_exception(&s->complete, e);
-+ return 0;
-+}
-+
-+/*
-+ * Hard coded magic.
-+ */
-+static int calc_max_buckets(void)
-+{
-+ unsigned long mem;
-+
-+ mem = num_physpages << PAGE_SHIFT;
-+ mem /= 50;
-+ mem /= sizeof(struct list_head);
-+
-+ return mem;
-+}
-+
-+/*
-+ * Rounds a number down to a power of 2.
-+ */
-+static inline uint32_t round_down(uint32_t n)
-+{
-+ while (n & (n - 1))
-+ n &= (n - 1);
-+ return n;
-+}
-+
-+/*
-+ * Allocate room for a suitable hash table.
-+ */
-+static int init_hash_tables(struct dm_snapshot *s)
-+{
-+ offset_t hash_size, cow_dev_size, origin_dev_size, max_buckets;
-+
-+ /*
-+ * Calculate based on the size of the original volume or
-+ * the COW volume...
-+ */
-+ cow_dev_size = get_dev_size(s->cow->dev);
-+ origin_dev_size = get_dev_size(s->origin->dev);
-+ max_buckets = calc_max_buckets();
-+
-+ hash_size = min(origin_dev_size, cow_dev_size) / s->chunk_size;
-+ hash_size = min(hash_size, max_buckets);
-+
-+ /* Round it down to a power of 2 */
-+ hash_size = round_down(hash_size);
-+ if (init_exception_table(&s->complete, hash_size))
-+ return -ENOMEM;
-+
-+ /*
-+ * Allocate hash table for in-flight exceptions
-+ * Make this smaller than the real hash table
-+ */
-+ hash_size >>= 3;
-+ if (!hash_size)
-+ hash_size = 64;
-+
-+ if (init_exception_table(&s->pending, hash_size)) {
-+ exit_exception_table(&s->complete, exception_cache);
-+ return -ENOMEM;
-+ }
-+
-+ return 0;
-+}
-+
-+/*
-+ * Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n>
-+ * <chunk-size>
-+ */
-+static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **argv, void **context)
-+{
-+ struct dm_snapshot *s;
-+ unsigned long chunk_size;
-+ unsigned long extent_size = 0L;
-+ int r = -EINVAL;
-+ char *persistent;
-+ char *origin_path;
-+ char *cow_path;
-+ char *value;
-+ int blocksize;
-+
-+ if (argc < 4) {
-+ *context = "dm-snapshot: Not enough arguments";
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ origin_path = argv[0];
-+ cow_path = argv[1];
-+ persistent = argv[2];
-+
-+ if ((*persistent & 0x5f) != 'P' && (*persistent & 0x5f) != 'N') {
-+ *context = "Persistent flag is not P or N";
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ chunk_size = simple_strtoul(argv[3], &value, 10);
-+ if (chunk_size == 0 || value == NULL) {
-+ *context = "Invalid chunk size";
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ /* Get the extent size for persistent snapshots */
-+ if ((*persistent & 0x5f) == 'P') {
-+ if (argc < 5) {
-+ *context = "No extent size specified";
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ extent_size = simple_strtoul(argv[4], &value, 10);
-+ if (extent_size == 0 || value == NULL) {
-+ *context = "Invalid extent size";
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+ }
-+
-+ s = kmalloc(sizeof(*s), GFP_KERNEL);
-+ if (s == NULL) {
-+ *context = "Cannot allocate snapshot context private structure";
-+ r = -ENOMEM;
-+ goto bad;
-+ }
-+
-+ r = dm_table_get_device(t, origin_path, 0, 0, &s->origin);
-+ if (r) {
-+ *context = "Cannot get origin device";
-+ goto bad_free;
-+ }
-+
-+ r = dm_table_get_device(t, cow_path, 0, 0, &s->cow);
-+ if (r) {
-+ dm_table_put_device(t, s->origin);
-+ *context = "Cannot get COW device";
-+ goto bad_free;
-+ }
-+
-+ /* Validate the extent and chunk sizes against the device block size */
-+ blocksize = get_hardsect_size(s->cow->dev);
-+ if (chunk_size % (blocksize / SECTOR_SIZE)) {
-+ *context = "Chunk size is not a multiple of device blocksize";
-+ r = -EINVAL;
-+ goto bad_putdev;
-+ }
-+
-+ if (extent_size % (blocksize / SECTOR_SIZE)) {
-+ *context = "Extent size is not a multiple of device blocksize";
-+ r = -EINVAL;
-+ goto bad_putdev;
-+ }
-+
-+ /* Check the sizes are small enough to fit in one kiovec */
-+ if (chunk_size > KIO_MAX_SECTORS) {
-+ *context = "Chunk size is too big";
-+ r = -EINVAL;
-+ goto bad_putdev;
-+ }
-+
-+ if (extent_size > KIO_MAX_SECTORS) {
-+ *context = "Extent size is too big";
-+ r = -EINVAL;
-+ goto bad_putdev;
-+ }
-+
-+ /* Check chunk_size is a power of 2 */
-+ if (chunk_size & (chunk_size - 1)) {
-+ *context = "Chunk size is not a power of 2";
-+ r = -EINVAL;
-+ goto bad_putdev;
-+ }
-+
-+ init_waitqueue_head(&s->waitq);
-+ s->chunk_size = chunk_size;
-+ s->chunk_mask = chunk_size - 1;
-+ s->type = *persistent;
-+ for (s->chunk_shift = 0; chunk_size;
-+ s->chunk_shift++, chunk_size >>= 1)
-+ ;
-+ s->chunk_shift--;
-+
-+ s->valid = 1;
-+ s->last_percent = 0;
-+ init_rwsem(&s->lock);
-+
-+ /* Allocate hash table for COW data */
-+ if (init_hash_tables(s)) {
-+ *context = "Unable to allocate hash table space";
-+ r = -ENOMEM;
-+ goto bad_putdev;
-+ }
-+
-+ /*
-+ * Check the persistent flag - done here because we need the iobuf
-+ * to check the LV header
-+ */
-+ s->store.snap = s;
-+
-+ if ((*persistent & 0x5f) == 'P')
-+ r = dm_create_persistent(&s->store, s->chunk_size);
-+ else
-+ r = dm_create_transient(&s->store, s, blocksize, context);
-+
-+ if (r) {
-+ *context = "Couldn't create exception store";
-+ r = -EINVAL;
-+ goto bad_free1;
-+ }
-+
-+ /* Flush IO to the origin device */
-+#if LVM_VFS_ENHANCEMENT
-+ fsync_dev_lockfs(s->origin->dev);
-+#else
-+ fsync_dev(s->origin->dev);
-+#endif
-+
-+ /* Add snapshot to the list of snapshots for this origin */
-+ if (register_snapshot(s)) {
-+ r = -EINVAL;
-+ *context = "Cannot register snapshot origin";
-+ goto bad_free2;
-+ }
-+#if LVM_VFS_ENHANCEMENT
-+ unlockfs(s->origin->dev);
-+#endif
-+ kcopyd_inc_client_count();
-+
-+ *context = s;
-+ return 0;
-+
-+ bad_free2:
-+ store_fn(s, destroy);
-+
-+ bad_free1:
-+ exit_exception_table(&s->pending, pending_cache);
-+ exit_exception_table(&s->complete, exception_cache);
-+
-+ bad_putdev:
-+ dm_table_put_device(t, s->cow);
-+ dm_table_put_device(t, s->origin);
-+
-+ bad_free:
-+ kfree(s);
-+
-+ bad:
-+ return r;
-+}
-+
-+static void snapshot_dtr(struct dm_table *t, void *context)
-+{
-+ struct dm_snapshot *s = (struct dm_snapshot *) context;
-+
-+ wake_up_interruptible(&s->waitq);
-+
-+ unregister_snapshot(s);
-+
-+ exit_exception_table(&s->pending, pending_cache);
-+ exit_exception_table(&s->complete, exception_cache);
-+
-+ /* Deallocate memory used */
-+ store_fn(s, destroy);
-+
-+ dm_table_put_device(t, s->origin);
-+ dm_table_put_device(t, s->cow);
-+ kfree(s);
-+
-+ kcopyd_dec_client_count();
-+}
-+
-+/*
-+ * We hold lists of buffer_heads, using the b_reqnext field.
-+ */
-+static void queue_buffer(struct buffer_head **queue, struct buffer_head *bh)
-+{
-+ bh->b_reqnext = *queue;
-+ *queue = bh;
-+}
-+
-+/*
-+ * Flush a list of buffers.
-+ */
-+static void flush_buffers(struct buffer_head *bh)
-+{
-+ struct buffer_head *n;
-+
-+ DMDEBUG("begin flush");
-+ while (bh) {
-+ n = bh->b_reqnext;
-+ bh->b_reqnext = NULL;
-+ DMDEBUG("flushing %p", bh);
-+ generic_make_request(WRITE, bh);
-+ bh = n;
-+ }
-+
-+ run_task_queue(&tq_disk);
-+}
-+
-+/*
-+ * Error a list of buffers.
-+ */
-+static void error_buffers(struct buffer_head *bh)
-+{
-+ struct buffer_head *n;
-+
-+ while (bh) {
-+ n = bh->b_reqnext;
-+ bh->b_reqnext = NULL;
-+ buffer_IO_error(bh);
-+ bh = n;
-+ }
-+}
-+
-+static void pending_complete(struct pending_exception *pe, int success)
-+{
-+ struct exception *e;
-+ struct dm_snapshot *s = pe->snap;
-+
-+ if (success) {
-+ e = alloc_exception();
-+ if (!e) {
-+ printk("Unable to allocate exception.");
-+ down_write(&s->lock);
-+ store_fn(s, drop_snapshot);
-+ s->valid = 0;
-+ up_write(&s->lock);
-+ return;
-+ }
-+
-+ /*
-+ * Add a proper exception, and remove the
-+ * inflight exception from the list.
-+ */
-+ down_write(&s->lock);
-+
-+ memcpy(e, &pe->e, sizeof(*e));
-+ insert_exception(&s->complete, e);
-+ remove_exception(&pe->e);
-+
-+ /* Submit any pending write BHs */
-+ up_write(&s->lock);
-+
-+ flush_buffers(pe->snapshot_bhs);
-+ DMDEBUG("Exception completed successfully.");
-+
-+ /* Notify any interested parties */
-+ if (s->store.percent_full) {
-+ int pc = s->store.percent_full(&s->store);
-+
-+ if (pc >= s->last_percent + WAKE_UP_PERCENT) {
-+ wake_up_interruptible(&s->waitq);
-+ s->last_percent = pc - pc % WAKE_UP_PERCENT;
-+ }
-+ }
-+
-+ } else {
-+ /* Read/write error - snapshot is unusable */
-+ DMERR("Error reading/writing snapshot");
-+
-+ down_write(&s->lock);
-+ store_fn(s, drop_snapshot);
-+ s->valid = 0;
-+ remove_exception(&pe->e);
-+ up_write(&s->lock);
-+
-+ error_buffers(pe->snapshot_bhs);
-+
-+ wake_up_interruptible(&s->waitq);
-+ DMDEBUG("Exception failed.");
-+ }
-+
-+ if (list_empty(&pe->siblings))
-+ flush_buffers(pe->origin_bhs);
-+ else
-+ list_del(&pe->siblings);
-+
-+ free_pending_exception(pe);
-+}
-+
-+static void commit_callback(void *context, int success)
-+{
-+ struct pending_exception *pe = (struct pending_exception *) context;
-+ pending_complete(pe, success);
-+}
-+
-+/*
-+ * Called when the copy I/O has finished. kcopyd actually runs
-+ * this code so don't block.
-+ */
-+static void copy_callback(int err, void *context)
-+{
-+ struct pending_exception *pe = (struct pending_exception *) context;
-+ struct dm_snapshot *s = pe->snap;
-+
-+ if (err)
-+ pending_complete(pe, 0);
-+
-+ else
-+ /* Update the metadata if we are persistent */
-+ s->store.commit_exception(&s->store, &pe->e, commit_callback,
-+ pe);
-+}
-+
-+/*
-+ * Dispatches the copy operation to kcopyd.
-+ */
-+static inline void start_copy(struct pending_exception *pe)
-+{
-+ struct dm_snapshot *s = pe->snap;
-+ struct kcopyd_region src, dest;
-+
-+ src.dev = s->origin->dev;
-+ src.sector = chunk_to_sector(s, pe->e.old_chunk);
-+ src.count = s->chunk_size;
-+
-+ dest.dev = s->cow->dev;
-+ dest.sector = chunk_to_sector(s, pe->e.new_chunk);
-+ dest.count = s->chunk_size;
-+
-+ if (!pe->started) {
-+ /* Hand over to kcopyd */
-+ kcopyd_copy(&src, &dest, copy_callback, pe);
-+ pe->started = 1;
-+ }
-+}
-+
-+/*
-+ * Looks to see if this snapshot already has a pending exception
-+ * for this chunk, otherwise it allocates a new one and inserts
-+ * it into the pending table.
-+ */
-+static struct pending_exception *find_pending_exception(struct dm_snapshot *s,
-+ struct buffer_head *bh)
-+{
-+ struct exception *e;
-+ struct pending_exception *pe;
-+ chunk_t chunk = sector_to_chunk(s, bh->b_rsector);
-+
-+ /*
-+ * Is there a pending exception for this already ?
-+ */
-+ e = lookup_exception(&s->pending, chunk);
-+ if (e) {
-+ /* cast the exception to a pending exception */
-+ pe = list_entry(e, struct pending_exception, e);
-+
-+ } else {
-+ /* Create a new pending exception */
-+ pe = alloc_pending_exception();
-+ if (!pe) {
-+ DMWARN("Couldn't allocate pending exception.");
-+ return NULL;
-+ }
-+
-+ pe->e.old_chunk = chunk;
-+ pe->origin_bhs = pe->snapshot_bhs = NULL;
-+ INIT_LIST_HEAD(&pe->siblings);
-+ pe->snap = s;
-+ pe->started = 0;
-+
-+ if (store_int_fn(s, prepare_exception, &pe->e)) {
-+ free_pending_exception(pe);
-+ s->valid = 0;
-+ return NULL;
-+ }
-+
-+ insert_exception(&s->pending, &pe->e);
-+ }
-+
-+ return pe;
-+}
-+
-+static inline void remap_exception(struct dm_snapshot *s, struct exception *e,
-+ struct buffer_head *bh)
-+{
-+ bh->b_rdev = s->cow->dev;
-+ bh->b_rsector = chunk_to_sector(s, e->new_chunk) +
-+ (bh->b_rsector & s->chunk_mask);
-+}
-+
-+static int snapshot_map(struct buffer_head *bh, int rw, void *context)
-+{
-+ struct exception *e;
-+ struct dm_snapshot *s = (struct dm_snapshot *) context;
-+ int r = 1;
-+ chunk_t chunk;
-+ struct pending_exception *pe;
-+
-+ chunk = sector_to_chunk(s, bh->b_rsector);
-+
-+ /* Full snapshots are not usable */
-+ if (!s->valid)
-+ return -1;
-+
-+ /*
-+ * Write to snapshot - higher level takes care of RW/RO
-+ * flags so we should only get this if we are
-+ * writeable.
-+ */
-+ if (rw == WRITE) {
-+
-+ down_write(&s->lock);
-+
-+ /* If the block is already remapped - use that, else remap it */
-+ e = lookup_exception(&s->complete, chunk);
-+ if (e)
-+ remap_exception(s, e, bh);
-+
-+ else {
-+ pe = find_pending_exception(s, bh);
-+
-+ if (!pe) {
-+ store_fn(s, drop_snapshot);
-+ s->valid = 0;
-+ }
-+
-+ queue_buffer(&pe->snapshot_bhs, bh);
-+ start_copy(pe);
-+ r = 0;
-+ }
-+
-+ up_write(&s->lock);
-+
-+ } else {
-+ /*
-+ * FIXME: this read path scares me because we
-+ * always use the origin when we have a pending
-+ * exception. However I can't think of a
-+ * situation where this is wrong - ejt.
-+ */
-+
-+ /* Do reads */
-+ down_read(&s->lock);
-+
-+ /* See if it it has been remapped */
-+ e = lookup_exception(&s->complete, chunk);
-+ if (e)
-+ remap_exception(s, e, bh);
-+ else
-+ bh->b_rdev = s->origin->dev;
-+
-+ up_read(&s->lock);
-+ }
-+
-+ return r;
-+}
-+
-+static void list_merge(struct list_head *l1, struct list_head *l2)
-+{
-+ struct list_head *l1_n, *l2_p;
-+
-+ l1_n = l1->next;
-+ l2_p = l2->prev;
-+
-+ l1->next = l2;
-+ l2->prev = l1;
-+
-+ l2_p->next = l1_n;
-+ l1_n->prev = l2_p;
-+}
-+
-+static int __origin_write(struct list_head *snapshots, struct buffer_head *bh)
-+{
-+ int r = 1;
-+ struct list_head *sl;
-+ struct dm_snapshot *snap;
-+ struct exception *e;
-+ struct pending_exception *pe, *last = NULL;
-+ chunk_t chunk;
-+
-+ /* Do all the snapshots on this origin */
-+ list_for_each(sl, snapshots) {
-+ snap = list_entry(sl, struct dm_snapshot, list);
-+
-+ /* Only deal with valid snapshots */
-+ if (!snap->valid)
-+ continue;
-+
-+ down_write(&snap->lock);
-+
-+ /*
-+ * Remember, different snapshots can have
-+ * different chunk sizes.
-+ */
-+ chunk = sector_to_chunk(snap, bh->b_rsector);
-+
-+ /*
-+ * Check exception table to see if block
-+ * is already remapped in this snapshot
-+ * and trigger an exception if not.
-+ */
-+ e = lookup_exception(&snap->complete, chunk);
-+ if (!e) {
-+ pe = find_pending_exception(snap, bh);
-+ if (!pe) {
-+ store_fn(snap, drop_snapshot);
-+ snap->valid = 0;
-+
-+ } else {
-+ if (last)
-+ list_merge(&pe->siblings,
-+ &last->siblings);
-+
-+ last = pe;
-+ r = 0;
-+ }
-+ }
-+
-+ up_write(&snap->lock);
-+ }
-+
-+ /*
-+ * Now that we have a complete pe list we can start the copying.
-+ */
-+ if (last) {
-+ pe = last;
-+ do {
-+ down_write(&pe->snap->lock);
-+ queue_buffer(&pe->origin_bhs, bh);
-+ start_copy(pe);
-+ up_write(&pe->snap->lock);
-+ pe = list_entry(pe->siblings.next,
-+ struct pending_exception, siblings);
-+
-+ } while (pe != last);
-+ }
-+
-+ return r;
-+}
-+
-+static int snapshot_status(status_type_t type, char *result,
-+ int maxlen, void *context)
-+{
-+ struct dm_snapshot *snap = (struct dm_snapshot *) context;
-+ char cow[16];
-+ char org[16];
-+
-+ switch (type) {
-+ case STATUSTYPE_INFO:
-+ if (!snap->valid)
-+ snprintf(result, maxlen, "Invalid");
-+ else {
-+ if (snap->store.percent_full)
-+ snprintf(result, maxlen, "%d%%",
-+ snap->store.percent_full(&snap->
-+ store));
-+ else
-+ snprintf(result, maxlen, "Unknown");
-+ }
-+ break;
-+
-+ case STATUSTYPE_TABLE:
-+ /*
-+ * kdevname returns a static pointer so we need
-+ * to make private copies if the output is to
-+ * make sense.
-+ */
-+ strncpy(cow, kdevname(snap->cow->dev), sizeof(cow));
-+ strncpy(org, kdevname(snap->origin->dev), sizeof(org));
-+ snprintf(result, maxlen, "%s %s %c %ld", org, cow,
-+ snap->type, snap->chunk_size);
-+ break;
-+ }
-+
-+ return 0;
-+}
-+
-+static int snapshot_wait(void *context, wait_queue_t *wq, int add)
-+{
-+ struct dm_snapshot *snap = (struct dm_snapshot *) context;
-+
-+ if (add)
-+ add_wait_queue(&snap->waitq, wq);
-+ else
-+ remove_wait_queue(&snap->waitq, wq);
-+
-+ return 0;
-+}
-+
-+/*
-+ * Called on a write from the origin driver.
-+ */
-+int do_origin(struct dm_dev *origin, struct buffer_head *bh)
-+{
-+ struct origin *o;
-+ int r;
-+
-+ down_read(&_origins_lock);
-+ o = __lookup_origin(origin->dev);
-+ if (!o)
-+ BUG();
-+
-+ r = __origin_write(&o->snapshots, bh);
-+ up_read(&_origins_lock);
-+
-+ return r;
-+}
-+
-+/*
-+ * Origin: maps a linear range of a device, with hooks for snapshotting.
-+ */
-+
-+/*
-+ * Construct an origin mapping: <dev_path>
-+ * The context for an origin is merely a 'struct dm_dev *'
-+ * pointing to the real device.
-+ */
-+static int origin_ctr(struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **argv, void **context)
-+{
-+ int r;
-+ struct dm_dev *dev;
-+
-+ if (argc != 1) {
-+ *context = "dm-origin: incorrect number of arguments";
-+ return -EINVAL;
-+ }
-+
-+ r = dm_table_get_device(t, argv[0], 0, l, &dev);
-+ if (r) {
-+ *context = "Cannot get target device";
-+ return r;
-+ }
-+
-+ *context = dev;
-+
-+ return 0;
-+}
-+
-+static void origin_dtr(struct dm_table *t, void *c)
-+{
-+ struct dm_dev *dev = (struct dm_dev *) c;
-+ dm_table_put_device(t, dev);
-+}
-+
-+static int origin_map(struct buffer_head *bh, int rw, void *context)
-+{
-+ struct dm_dev *dev = (struct dm_dev *) context;
-+ bh->b_rdev = dev->dev;
-+
-+ /* Only tell snapshots if this is a write */
-+ return (rw == WRITE) ? do_origin(dev, bh) : 1;
-+}
-+
-+static int origin_status(status_type_t type, char *result,
-+ int maxlen, void *context)
-+{
-+ struct dm_dev *dev = (struct dm_dev *) context;
-+
-+ switch (type) {
-+ case STATUSTYPE_INFO:
-+ result[0] = '\0';
-+ break;
-+
-+ case STATUSTYPE_TABLE:
-+ snprintf(result, maxlen, "%s", kdevname(dev->dev));
-+ break;
-+ }
-+
-+ return 0;
-+}
-+
-+static struct target_type origin_target = {
-+ name: "snapshot-origin",
-+ module: THIS_MODULE,
-+ ctr: origin_ctr,
-+ dtr: origin_dtr,
-+ map: origin_map,
-+ status: origin_status,
-+ wait: NULL,
-+ err: NULL
-+};
-+
-+static struct target_type snapshot_target = {
-+ name: "snapshot",
-+ module: THIS_MODULE,
-+ ctr: snapshot_ctr,
-+ dtr: snapshot_dtr,
-+ map: snapshot_map,
-+ status: snapshot_status,
-+ wait: snapshot_wait,
-+ err: NULL
-+};
-+
-+int __init dm_snapshot_init(void)
-+{
-+ int r;
-+
-+ r = dm_register_target(&snapshot_target);
-+ if (r) {
-+ DMERR("snapshot target register failed %d", r);
-+ return r;
-+ }
-+
-+ r = dm_register_target(&origin_target);
-+ if (r < 0) {
-+ DMERR("Device mapper: Origin: register failed %d\n", r);
-+ goto bad1;
-+ }
-+
-+ r = init_origin_hash();
-+ if (r) {
-+ DMERR("init_origin_hash failed.");
-+ goto bad2;
-+ }
-+
-+ exception_cache = kmem_cache_create("dm-snapshot-ex",
-+ sizeof(struct exception),
-+ __alignof__(struct exception),
-+ 0, NULL, NULL);
-+ if (!exception_cache) {
-+ DMERR("Couldn't create exception cache.");
-+ r = -ENOMEM;
-+ goto bad3;
-+ }
-+
-+ pending_cache =
-+ kmem_cache_create("dm-snapshot-in",
-+ sizeof(struct pending_exception),
-+ __alignof__(struct pending_exception),
-+ 0, NULL, NULL);
-+ if (!pending_cache) {
-+ DMERR("Couldn't create pending cache.");
-+ r = -ENOMEM;
-+ goto bad4;
-+ }
-+
-+ pending_pool = mempool_create(128, mempool_alloc_slab,
-+ mempool_free_slab, pending_cache);
-+ if (!pending_pool) {
-+ DMERR("Couldn't create pending pool.");
-+ r = -ENOMEM;
-+ goto bad5;
-+ }
-+
-+ return 0;
-+
-+ bad5:
-+ kmem_cache_destroy(pending_cache);
-+ bad4:
-+ kmem_cache_destroy(exception_cache);
-+ bad3:
-+ exit_origin_hash();
-+ bad2:
-+ dm_unregister_target(&origin_target);
-+ bad1:
-+ dm_unregister_target(&snapshot_target);
-+ return r;
-+}
-+
-+void dm_snapshot_exit(void)
-+{
-+ int r;
-+
-+ r = dm_unregister_target(&snapshot_target);
-+ if (r)
-+ DMERR("snapshot unregister failed %d", r);
-+
-+ r = dm_unregister_target(&origin_target);
-+ if (r)
-+ DMERR("origin unregister failed %d", r);
-+
-+ exit_origin_hash();
-+ mempool_destroy(pending_pool);
-+ kmem_cache_destroy(pending_cache);
-+ kmem_cache_destroy(exception_cache);
-+}
-+
-+/*
-+ * Overrides for Emacs so that we follow Linus's tabbing style.
-+ * Emacs will notice this stuff at the end of the file and automatically
-+ * adjust the settings for this buffer only. This must remain at the end
-+ * of the file.
-+ * ---------------------------------------------------------------------------
-+ * Local variables:
-+ * c-file-style: "linux"
-+ * End:
-+ */
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-snapshot.h linux/drivers/md/dm-snapshot.h
---- linux-2.4.19-pre8/drivers/md/dm-snapshot.h Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-snapshot.h Mon May 20 15:02:16 2002
-@@ -0,0 +1,149 @@
-+/*
-+ * dm-snapshot.c
-+ *
-+ * Copyright (C) 2001-2002 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#ifndef DM_SNAPSHOT_H
-+#define DM_SNAPSHOT_H
-+
-+#include "dm.h"
-+#include <linux/blkdev.h>
-+
-+struct exception_table {
-+ uint32_t hash_mask;
-+ struct list_head *table;
-+};
-+
-+/*
-+ * The snapshot code deals with largish chunks of the disk at a
-+ * time. Typically 64k - 256k.
-+ */
-+/* FIXME: can we get away with limiting these to a uint32_t ? */
-+typedef offset_t chunk_t;
-+
-+/*
-+ * An exception is used where an old chunk of data has been
-+ * replaced by a new one.
-+ */
-+struct exception {
-+ struct list_head hash_list;
-+
-+ chunk_t old_chunk;
-+ chunk_t new_chunk;
-+};
-+
-+/*
-+ * Abstraction to handle the meta/layout of exception stores (the
-+ * COW device).
-+ */
-+struct exception_store {
-+
-+ /*
-+ * Destroys this object when you've finished with it.
-+ */
-+ void (*destroy) (struct exception_store *store);
-+
-+ /*
-+ * Find somewhere to store the next exception.
-+ */
-+ int (*prepare_exception) (struct exception_store *store,
-+ struct exception *e);
-+
-+ /*
-+ * Update the metadata with this exception.
-+ */
-+ void (*commit_exception) (struct exception_store *store,
-+ struct exception *e,
-+ void (*callback) (void *, int success),
-+ void *callback_context);
-+
-+ /*
-+ * The snapshot is invalid, note this in the metadata.
-+ */
-+ void (*drop_snapshot) (struct exception_store *store);
-+
-+ /*
-+ * Return the %age full of the snapshot
-+ */
-+ int (*percent_full) (struct exception_store *store);
-+
-+ struct dm_snapshot *snap;
-+ void *context;
-+};
-+
-+struct dm_snapshot {
-+ struct rw_semaphore lock;
-+
-+ struct dm_dev *origin;
-+ struct dm_dev *cow;
-+
-+ /* List of snapshots per Origin */
-+ struct list_head list;
-+
-+ /* Processes wait on this when they want to block on status changes */
-+ wait_queue_head_t waitq;
-+
-+ /* Size of data blocks saved - must be a power of 2 */
-+ chunk_t chunk_size;
-+ chunk_t chunk_mask;
-+ chunk_t chunk_shift;
-+
-+ /* You can't use a snapshot if this is 0 (e.g. if full) */
-+ int valid;
-+
-+ /* Used for display of table */
-+ char type;
-+
-+ /* The last percentage we notified */
-+ int last_percent;
-+
-+ struct exception_table pending;
-+ struct exception_table complete;
-+
-+ /* The on disk metadata handler */
-+ struct exception_store store;
-+};
-+
-+/*
-+ * Used by the exception stores to load exceptions hen
-+ * initialising.
-+ */
-+int dm_add_exception(struct dm_snapshot *s, chunk_t old, chunk_t new);
-+
-+/*
-+ * Constructor and destructor for the default persistent
-+ * store.
-+ */
-+int dm_create_persistent(struct exception_store *store, uint32_t chunk_size);
-+
-+int dm_create_transient(struct exception_store *store,
-+ struct dm_snapshot *s, int blocksize, void **error);
-+
-+/*
-+ * Return the number of sectors in the device.
-+ */
-+static inline offset_t get_dev_size(kdev_t dev)
-+{
-+ int *sizes;
-+
-+ sizes = blk_size[MAJOR(dev)];
-+ if (sizes)
-+ return sizes[MINOR(dev)] << 1;
-+
-+ return 0;
-+}
-+
-+static inline chunk_t sector_to_chunk(struct dm_snapshot *s, offset_t sector)
-+{
-+ return (sector & ~s->chunk_mask) >> s->chunk_shift;
-+}
-+
-+static inline offset_t chunk_to_sector(struct dm_snapshot *s, chunk_t chunk)
-+{
-+ return chunk << s->chunk_shift;
-+}
-+
-+#endif
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-stripe.c linux/drivers/md/dm-stripe.c
---- linux-2.4.19-pre8/drivers/md/dm-stripe.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-stripe.c Mon May 20 14:20:28 2002
-@@ -0,0 +1,230 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+
-+#include <linux/module.h>
-+#include <linux/init.h>
-+#include <linux/blkdev.h>
-+
-+struct stripe {
-+ struct dm_dev *dev;
-+ offset_t physical_start;
-+};
-+
-+struct stripe_c {
-+ offset_t logical_start;
-+ uint32_t stripes;
-+
-+ /* The size of this target / num. stripes */
-+ uint32_t stripe_width;
-+
-+ /* stripe chunk size */
-+ uint32_t chunk_shift;
-+ offset_t chunk_mask;
-+
-+ struct stripe stripe[0];
-+};
-+
-+static inline struct stripe_c *alloc_context(int stripes)
-+{
-+ size_t len = sizeof(struct stripe_c) +
-+ (sizeof(struct stripe) * stripes);
-+
-+ return kmalloc(len, GFP_KERNEL);
-+}
-+
-+/*
-+ * Parse a single <dev> <sector> pair
-+ */
-+static int get_stripe(struct dm_table *t, struct stripe_c *sc,
-+ int stripe, char **argv)
-+{
-+ char *end;
-+ unsigned long start;
-+
-+ start = simple_strtoul(argv[1], &end, 10);
-+ if (*end)
-+ return -EINVAL;
-+
-+ if (dm_table_get_device(t, argv[0], start, sc->stripe_width,
-+ &sc->stripe[stripe].dev))
-+ return -ENXIO;
-+
-+ sc->stripe[stripe].physical_start = start;
-+ return 0;
-+}
-+
-+/*
-+ * Construct a striped mapping.
-+ * <number of stripes> <chunk size (2^^n)> [<dev_path> <offset>]+
-+ */
-+static int stripe_ctr(struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **argv, void **context)
-+{
-+ struct stripe_c *sc;
-+ uint32_t stripes;
-+ uint32_t chunk_size;
-+ char *end;
-+ int r, i;
-+
-+ if (argc < 2) {
-+ *context = "dm-stripe: Not enough arguments";
-+ return -EINVAL;
-+ }
-+
-+ stripes = simple_strtoul(argv[0], &end, 10);
-+ if (*end) {
-+ *context = "dm-stripe: Invalid stripe count";
-+ return -EINVAL;
-+ }
-+
-+ chunk_size = simple_strtoul(argv[1], &end, 10);
-+ if (*end) {
-+ *context = "dm-stripe: Invalid chunk_size";
-+ return -EINVAL;
-+ }
-+
-+ if (l % stripes) {
-+ *context = "dm-stripe: Target length not divisable by "
-+ "number of stripes";
-+ return -EINVAL;
-+ }
-+
-+ sc = alloc_context(stripes);
-+ if (!sc) {
-+ *context = "dm-stripe: Memory allocation for striped context "
-+ "failed";
-+ return -ENOMEM;
-+ }
-+
-+ sc->logical_start = b;
-+ sc->stripes = stripes;
-+ sc->stripe_width = l / stripes;
-+
-+ /*
-+ * chunk_size is a power of two
-+ */
-+ if (!chunk_size || (chunk_size & (chunk_size - 1))) {
-+ *context = "dm-stripe: Invalid chunk size";
-+ kfree(sc);
-+ return -EINVAL;
-+ }
-+
-+ sc->chunk_mask = chunk_size - 1;
-+ for (sc->chunk_shift = 0; chunk_size; sc->chunk_shift++)
-+ chunk_size >>= 1;
-+ sc->chunk_shift--;
-+
-+ /*
-+ * Get the stripe destinations.
-+ */
-+ for (i = 0; i < stripes; i++) {
-+ if (argc < 2) {
-+ *context = "dm-stripe: Not enough destinations "
-+ "specified";
-+ kfree(sc);
-+ return -EINVAL;
-+ }
-+
-+ argv += 2;
-+
-+ r = get_stripe(t, sc, i, argv);
-+ if (r < 0) {
-+ *context = "dm-stripe: Couldn't parse stripe "
-+ "destination";
-+ while (i--)
-+ dm_table_put_device(t, sc->stripe[i].dev);
-+ kfree(sc);
-+ return r;
-+ }
-+ }
-+
-+ *context = sc;
-+ return 0;
-+}
-+
-+static void stripe_dtr(struct dm_table *t, void *c)
-+{
-+ unsigned int i;
-+ struct stripe_c *sc = (struct stripe_c *) c;
-+
-+ for (i = 0; i < sc->stripes; i++)
-+ dm_table_put_device(t, sc->stripe[i].dev);
-+
-+ kfree(sc);
-+}
-+
-+static int stripe_map(struct buffer_head *bh, int rw, void *context)
-+{
-+ struct stripe_c *sc = (struct stripe_c *) context;
-+
-+ offset_t offset = bh->b_rsector - sc->logical_start;
-+ uint32_t chunk = (uint32_t) (offset >> sc->chunk_shift);
-+ uint32_t stripe = chunk % sc->stripes; /* 32bit modulus */
-+ chunk = chunk / sc->stripes;
-+
-+ bh->b_rdev = sc->stripe[stripe].dev->dev;
-+ bh->b_rsector = sc->stripe[stripe].physical_start +
-+ (chunk << sc->chunk_shift) + (offset & sc->chunk_mask);
-+ return 1;
-+}
-+
-+static int stripe_status(status_type_t type, char *result, int maxlen,
-+ void *context)
-+{
-+ struct stripe_c *sc = (struct stripe_c *) context;
-+ int offset;
-+ int i;
-+
-+ switch (type) {
-+ case STATUSTYPE_INFO:
-+ result[0] = '\0';
-+ break;
-+
-+ case STATUSTYPE_TABLE:
-+ offset = snprintf(result, maxlen, "%d %ld",
-+ sc->stripes, sc->chunk_mask + 1);
-+ for (i = 0; i < sc->stripes; i++) {
-+ offset +=
-+ snprintf(result + offset, maxlen - offset,
-+ " %s %ld",
-+ kdevname(sc->stripe[i].dev->dev),
-+ sc->stripe[i].physical_start);
-+ }
-+ break;
-+ }
-+ return 0;
-+}
-+
-+static struct target_type stripe_target = {
-+ name: "striped",
-+ module: THIS_MODULE,
-+ ctr: stripe_ctr,
-+ dtr: stripe_dtr,
-+ map: stripe_map,
-+ status: stripe_status,
-+ wait: NULL,
-+};
-+
-+int __init dm_stripe_init(void)
-+{
-+ int r;
-+
-+ r = dm_register_target(&stripe_target);
-+ if (r < 0)
-+ DMWARN("striped target registration failed");
-+
-+ return r;
-+}
-+
-+void dm_stripe_exit(void)
-+{
-+ if (dm_unregister_target(&stripe_target))
-+ DMWARN("striped target unregistration failed");
-+
-+ return;
-+}
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-table.c linux/drivers/md/dm-table.c
---- linux-2.4.19-pre8/drivers/md/dm-table.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-table.c Fri May 10 16:13:11 2002
-@@ -0,0 +1,410 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+
-+#include <linux/blkdev.h>
-+
-+/* ceiling(n / size) * size */
-+static inline unsigned long round_up(unsigned long n, unsigned long size)
-+{
-+ unsigned long r = n % size;
-+ return n + (r ? (size - r) : 0);
-+}
-+
-+/* ceiling(n / size) */
-+static inline unsigned long div_up(unsigned long n, unsigned long size)
-+{
-+ return round_up(n, size) / size;
-+}
-+
-+/* similar to ceiling(log_size(n)) */
-+static uint int_log(unsigned long n, unsigned long base)
-+{
-+ int result = 0;
-+
-+ while (n > 1) {
-+ n = div_up(n, base);
-+ result++;
-+ }
-+
-+ return result;
-+}
-+
-+/*
-+ * return the highest key that you could lookup
-+ * from the n'th node on level l of the btree.
-+ */
-+static offset_t high(struct dm_table *t, int l, int n)
-+{
-+ for (; l < t->depth - 1; l++)
-+ n = get_child(n, CHILDREN_PER_NODE - 1);
-+
-+ if (n >= t->counts[l])
-+ return (offset_t) - 1;
-+
-+ return get_node(t, l, n)[KEYS_PER_NODE - 1];
-+}
-+
-+/*
-+ * fills in a level of the btree based on the
-+ * highs of the level below it.
-+ */
-+static int setup_btree_index(int l, struct dm_table *t)
-+{
-+ int n, k;
-+ offset_t *node;
-+
-+ for (n = 0; n < t->counts[l]; n++) {
-+ node = get_node(t, l, n);
-+
-+ for (k = 0; k < KEYS_PER_NODE; k++)
-+ node[k] = high(t, l + 1, get_child(n, k));
-+ }
-+
-+ return 0;
-+}
-+
-+/*
-+ * highs, and targets are managed as dynamic
-+ * arrays during a table load.
-+ */
-+static int alloc_targets(struct dm_table *t, int num)
-+{
-+ offset_t *n_highs;
-+ struct target *n_targets;
-+ int n = t->num_targets;
-+ unsigned long size = (sizeof(struct target) + sizeof(offset_t)) * num;
-+
-+ n_highs = (offset_t *) vmalloc(size);
-+ if (!n_highs)
-+ return -ENOMEM;
-+
-+ memset(n_highs, 0, size);
-+
-+ n_targets = (struct target *) (n_highs + num);
-+
-+ if (n) {
-+ memcpy(n_highs, t->highs, sizeof(*n_highs) * n);
-+ memcpy(n_targets, t->targets, sizeof(*n_targets) * n);
-+ }
-+
-+ memset(n_highs + n, -1, sizeof(*n_highs) * (num - n));
-+ if (t->highs)
-+ vfree(t->highs);
-+
-+ t->num_allocated = num;
-+ t->highs = n_highs;
-+ t->targets = n_targets;
-+
-+ return 0;
-+}
-+
-+int dm_table_create(struct dm_table **result)
-+{
-+ struct dm_table *t = kmalloc(sizeof(struct dm_table), GFP_NOIO);
-+
-+ if (!t)
-+ return -ENOMEM;
-+
-+ memset(t, 0, sizeof(*t));
-+ INIT_LIST_HEAD(&t->devices);
-+
-+ /* allocate a single node's worth of targets to begin with */
-+ if (alloc_targets(t, KEYS_PER_NODE)) {
-+ kfree(t);
-+ t = NULL;
-+ return -ENOMEM;
-+ }
-+
-+ *result = t;
-+ return 0;
-+}
-+
-+static void free_devices(struct list_head *devices)
-+{
-+ struct list_head *tmp, *next;
-+
-+ for (tmp = devices->next; tmp != devices; tmp = next) {
-+ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
-+ next = tmp->next;
-+ kfree(dd);
-+ }
-+}
-+
-+void dm_table_destroy(struct dm_table *t)
-+{
-+ int i;
-+
-+ /* free the indexes (see dm_table_complete) */
-+ if (t->depth >= 2)
-+ vfree(t->index[t->depth - 2]);
-+
-+ /* free the targets */
-+ for (i = 0; i < t->num_targets; i++) {
-+ struct target *tgt = &t->targets[i];
-+
-+ dm_put_target_type(t->targets[i].type);
-+
-+ if (tgt->type->dtr)
-+ tgt->type->dtr(t, tgt->private);
-+ }
-+
-+ vfree(t->highs);
-+
-+ /* free the device list */
-+ if (t->devices.next != &t->devices) {
-+ DMWARN("devices still present during destroy: "
-+ "dm_table_remove_device calls missing");
-+
-+ free_devices(&t->devices);
-+ }
-+
-+ kfree(t);
-+}
-+
-+/*
-+ * Checks to see if we need to extend highs or targets.
-+ */
-+static inline int check_space(struct dm_table *t)
-+{
-+ if (t->num_targets >= t->num_allocated)
-+ return alloc_targets(t, t->num_allocated * 2);
-+
-+ return 0;
-+}
-+
-+/*
-+ * Convert a device path to a kdev_t.
-+ */
-+int lookup_device(const char *path, kdev_t *dev)
-+{
-+ int r;
-+ struct nameidata nd;
-+ struct inode *inode;
-+
-+ if (!path_init(path, LOOKUP_FOLLOW, &nd))
-+ return 0;
-+
-+ if ((r = path_walk(path, &nd)))
-+ goto bad;
-+
-+ inode = nd.dentry->d_inode;
-+ if (!inode) {
-+ r = -ENOENT;
-+ goto bad;
-+ }
-+
-+ if (!S_ISBLK(inode->i_mode)) {
-+ r = -EINVAL;
-+ goto bad;
-+ }
-+
-+ *dev = inode->i_rdev;
-+
-+ bad:
-+ path_release(&nd);
-+ return r;
-+}
-+
-+/*
-+ * See if we've already got a device in the list.
-+ */
-+static struct dm_dev *find_device(struct list_head *l, kdev_t dev)
-+{
-+ struct list_head *tmp;
-+
-+ list_for_each(tmp, l) {
-+ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
-+ if (dd->dev == dev)
-+ return dd;
-+ }
-+
-+ return NULL;
-+}
-+
-+/*
-+ * Open a device so we can use it as a map destination.
-+ */
-+static int open_dev(struct dm_dev *d)
-+{
-+ int err;
-+
-+ if (d->bd)
-+ BUG();
-+
-+ if (!(d->bd = bdget(kdev_t_to_nr(d->dev))))
-+ return -ENOMEM;
-+
-+ if ((err = blkdev_get(d->bd, FMODE_READ | FMODE_WRITE, 0, BDEV_FILE)))
-+ return err;
-+
-+ return 0;
-+}
-+
-+/*
-+ * Close a device that we've been using.
-+ */
-+static void close_dev(struct dm_dev *d)
-+{
-+ if (!d->bd)
-+ return;
-+
-+ blkdev_put(d->bd, BDEV_FILE);
-+ d->bd = NULL;
-+}
-+
-+/*
-+ * If possible (ie. blk_size[major] is set), this
-+ * checks an area of a destination device is
-+ * valid.
-+ */
-+static int check_device_area(kdev_t dev, offset_t start, offset_t len)
-+{
-+ int *sizes;
-+ offset_t dev_size;
-+
-+ if (!(sizes = blk_size[MAJOR(dev)]) || !(dev_size = sizes[MINOR(dev)]))
-+ /* we don't know the device details,
-+ * so give the benefit of the doubt */
-+ return 1;
-+
-+ /* convert to 512-byte sectors */
-+ dev_size <<= 1;
-+
-+ return ((start < dev_size) && (len <= (dev_size - start)));
-+}
-+
-+/*
-+ * Add a device to the list, or just increment the usage count
-+ * if it's already present.
-+ */
-+int dm_table_get_device(struct dm_table *t, const char *path,
-+ offset_t start, offset_t len, struct dm_dev **result)
-+{
-+ int r;
-+ kdev_t dev;
-+ struct dm_dev *dd;
-+ int major, minor;
-+
-+ if (sscanf(path, "%x:%x", &major, &minor) == 2) {
-+ /* Extract the major/minor numbers */
-+ dev = MKDEV(major, minor);
-+ } else {
-+ /* convert the path to a device */
-+ if ((r = lookup_device(path, &dev)))
-+ return r;
-+ }
-+
-+ dd = find_device(&t->devices, dev);
-+ if (!dd) {
-+ dd = kmalloc(sizeof(*dd), GFP_KERNEL);
-+ if (!dd)
-+ return -ENOMEM;
-+
-+ dd->dev = dev;
-+ dd->bd = NULL;
-+
-+ if ((r = open_dev(dd))) {
-+ kfree(dd);
-+ return r;
-+ }
-+
-+ atomic_set(&dd->count, 0);
-+ list_add(&dd->list, &t->devices);
-+ }
-+ atomic_inc(&dd->count);
-+
-+ if (!check_device_area(dd->dev, start, len)) {
-+ DMWARN("device %s too small for target", path);
-+ dm_table_put_device(t, dd);
-+ return -EINVAL;
-+ }
-+
-+ *result = dd;
-+
-+ return 0;
-+}
-+
-+/*
-+ * Decrement a devices use count and remove it if neccessary.
-+ */
-+void dm_table_put_device(struct dm_table *t, struct dm_dev *dd)
-+{
-+ if (atomic_dec_and_test(&dd->count)) {
-+ close_dev(dd);
-+ list_del(&dd->list);
-+ kfree(dd);
-+ }
-+}
-+
-+/*
-+ * Adds a target to the map
-+ */
-+int dm_table_add_target(struct dm_table *t, offset_t highs,
-+ struct target_type *type, void *private)
-+{
-+ int r, n;
-+
-+ if ((r = check_space(t)))
-+ return r;
-+
-+ n = t->num_targets++;
-+ t->highs[n] = highs;
-+ t->targets[n].type = type;
-+ t->targets[n].private = private;
-+
-+ return 0;
-+}
-+
-+static int setup_indexes(struct dm_table *t)
-+{
-+ int i, total = 0;
-+ offset_t *indexes;
-+
-+ /* allocate the space for *all* the indexes */
-+ for (i = t->depth - 2; i >= 0; i--) {
-+ t->counts[i] = div_up(t->counts[i + 1], CHILDREN_PER_NODE);
-+ total += t->counts[i];
-+ }
-+
-+ indexes = (offset_t *) vmalloc((unsigned long) NODE_SIZE * total);
-+ if (!indexes)
-+ return -ENOMEM;
-+
-+ /* set up internal nodes, bottom-up */
-+ for (i = t->depth - 2, total = 0; i >= 0; i--) {
-+ t->index[i] = indexes;
-+ indexes += (KEYS_PER_NODE * t->counts[i]);
-+ setup_btree_index(i, t);
-+ }
-+
-+ return 0;
-+}
-+
-+/*
-+ * Builds the btree to index the map
-+ */
-+int dm_table_complete(struct dm_table *t)
-+{
-+ int leaf_nodes, r = 0;
-+
-+ /* how many indexes will the btree have ? */
-+ leaf_nodes = div_up(t->num_targets, KEYS_PER_NODE);
-+ t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
-+
-+ /* leaf layer has already been set up */
-+ t->counts[t->depth - 1] = leaf_nodes;
-+ t->index[t->depth - 1] = t->highs;
-+
-+ if (t->depth >= 2)
-+ r = setup_indexes(t);
-+
-+ return r;
-+}
-+
-+EXPORT_SYMBOL(dm_table_get_device);
-+EXPORT_SYMBOL(dm_table_put_device);
-diff -ruN linux-2.4.19-pre8/drivers/md/dm-target.c linux/drivers/md/dm-target.c
---- linux-2.4.19-pre8/drivers/md/dm-target.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-target.c Mon May 20 14:13:44 2002
-@@ -0,0 +1,243 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+
-+#include <linux/kmod.h>
-+
-+struct tt_internal {
-+ struct target_type tt;
-+
-+ struct list_head list;
-+ long use;
-+};
-+
-+static LIST_HEAD(_targets);
-+static rwlock_t _lock = RW_LOCK_UNLOCKED;
-+
-+#define DM_MOD_NAME_SIZE 32
-+
-+/*
-+ * Destructively splits up the argument list to pass to ctr.
-+ */
-+int split_args(int max, int *argc, char **argv, char *input)
-+{
-+ char *start, *end = input, *out;
-+ *argc = 0;
-+
-+ while (1) {
-+ start = end;
-+
-+ /* Skip whitespace */
-+ while (*start && isspace(*start))
-+ start++;
-+
-+ if (!*start)
-+ break; /* success, we hit the end */
-+
-+ /* 'out' is used to remove any back-quotes */
-+ end = out = start;
-+ while (*end) {
-+ /* Everything apart from '\0' can be quoted */
-+ if (*end == '\\' && *(end + 1)) {
-+ *out++ = *(end + 1);
-+ end += 2;
-+ continue;
-+ }
-+
-+ if (isspace(*end))
-+ break; /* end of token */
-+
-+ *out++ = *end++;
-+ }
-+
-+ /* have we already filled the array ? */
-+ if ((*argc + 1) > max)
-+ return -EINVAL;
-+
-+ /* we know this is whitespace */
-+ if (*end)
-+ end++;
-+
-+ /* terminate the string and put it in the array */
-+ *out = '\0';
-+ argv[*argc] = start;
-+ (*argc)++;
-+ }
-+
-+ return 0;
-+}
-+
-+static inline struct tt_internal *__find_target_type(const char *name)
-+{
-+ struct list_head *tih;
-+ struct tt_internal *ti;
-+
-+ list_for_each(tih, &_targets) {
-+ ti = list_entry(tih, struct tt_internal, list);
-+
-+ if (!strcmp(name, ti->tt.name))
-+ return ti;
-+ }
-+
-+ return NULL;
-+}
-+
-+static struct tt_internal *get_target_type(const char *name)
-+{
-+ struct tt_internal *ti;
-+
-+ read_lock(&_lock);
-+ ti = __find_target_type(name);
-+
-+ if (ti) {
-+ if (ti->use == 0 && ti->tt.module)
-+ __MOD_INC_USE_COUNT(ti->tt.module);
-+ ti->use++;
-+ }
-+ read_unlock(&_lock);
-+
-+ return ti;
-+}
-+
-+static void load_module(const char *name)
-+{
-+ char module_name[DM_MOD_NAME_SIZE] = "dm-";
-+
-+ /* Length check for strcat() below */
-+ if (strlen(name) > (DM_MOD_NAME_SIZE - 4))
-+ return;
-+
-+ strcat(module_name, name);
-+ request_module(module_name);
-+
-+ return;
-+}
-+
-+struct target_type *dm_get_target_type(const char *name)
-+{
-+ struct tt_internal *ti = get_target_type(name);
-+
-+ if (!ti) {
-+ load_module(name);
-+ ti = get_target_type(name);
-+ }
-+
-+ return ti ? &ti->tt : NULL;
-+}
-+
-+void dm_put_target_type(struct target_type *t)
-+{
-+ struct tt_internal *ti = (struct tt_internal *) t;
-+
-+ read_lock(&_lock);
-+ if (--ti->use == 0 && ti->tt.module)
-+ __MOD_DEC_USE_COUNT(ti->tt.module);
-+
-+ if (ti->use < 0)
-+ BUG();
-+ read_unlock(&_lock);
-+
-+ return;
-+}
-+
-+static struct tt_internal *alloc_target(struct target_type *t)
-+{
-+ struct tt_internal *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
-+
-+ if (ti) {
-+ memset(ti, 0, sizeof(*ti));
-+ ti->tt = *t;
-+ }
-+
-+ return ti;
-+}
-+
-+int dm_register_target(struct target_type *t)
-+{
-+ int rv = 0;
-+ struct tt_internal *ti = alloc_target(t);
-+
-+ if (!ti)
-+ return -ENOMEM;
-+
-+ write_lock(&_lock);
-+ if (__find_target_type(t->name))
-+ rv = -EEXIST;
-+ else
-+ list_add(&ti->list, &_targets);
-+
-+ write_unlock(&_lock);
-+ return rv;
-+}
-+
-+int dm_unregister_target(struct target_type *t)
-+{
-+ struct tt_internal *ti;
-+
-+ write_lock(&_lock);
-+ if (!(ti = __find_target_type(t->name))) {
-+ write_unlock(&_lock);
-+ return -EINVAL;
-+ }
-+
-+ if (ti->use) {
-+ write_unlock(&_lock);
-+ return -ETXTBSY;
-+ }
-+
-+ list_del(&ti->list);
-+ kfree(ti);
-+
-+ write_unlock(&_lock);
-+ return 0;
-+}
-+
-+/*
-+ * io-err: always fails an io, useful for bringing
-+ * up LV's that have holes in them.
-+ */
-+static int io_err_ctr(struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **args, void **context)
-+{
-+ *context = NULL;
-+ return 0;
-+}
-+
-+static void io_err_dtr(struct dm_table *t, void *c)
-+{
-+ /* empty */
-+ return;
-+}
-+
-+static int io_err_map(struct buffer_head *bh, int rw, void *context)
-+{
-+ buffer_IO_error(bh);
-+ return 0;
-+}
-+
-+static struct target_type error_target = {
-+ name: "error",
-+ ctr: io_err_ctr,
-+ dtr: io_err_dtr,
-+ map: io_err_map,
-+ status: NULL,
-+ wait: NULL,
-+};
-+
-+int dm_target_init(void)
-+{
-+ return dm_register_target(&error_target);
-+}
-+
-+void dm_target_exit(void)
-+{
-+ if (dm_unregister_target(&error_target))
-+ DMWARN("error target unregistration failed");
-+}
-+
-+EXPORT_SYMBOL(dm_register_target);
-+EXPORT_SYMBOL(dm_unregister_target);
-diff -ruN linux-2.4.19-pre8/drivers/md/dm.c linux/drivers/md/dm.c
---- linux-2.4.19-pre8/drivers/md/dm.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm.c Mon May 20 16:47:30 2002
-@@ -0,0 +1,1153 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include "dm.h"
-+#include "kcopyd.h"
-+
-+#include <linux/blk.h>
-+#include <linux/blkpg.h>
-+
-+/* we only need this for the lv_bmap struct definition, not happy */
-+#include <linux/lvm.h>
-+
-+#define DEFAULT_READ_AHEAD 64
-+
-+static const char *_name = DM_NAME;
-+static const char *_version = "0.94.11-ioctl (2002-05-20)";
-+static const char *_email = "lvm-devel@lists.sistina.com";
-+
-+static int major = 0;
-+static int _major = 0;
-+
-+struct io_hook {
-+ struct mapped_device *md;
-+ struct target *target;
-+ int rw;
-+
-+ void (*end_io) (struct buffer_head * bh, int uptodate);
-+ void *context;
-+};
-+
-+static kmem_cache_t *_io_hook_cache;
-+
-+static struct mapped_device *_devs[MAX_DEVICES];
-+static struct rw_semaphore _dev_locks[MAX_DEVICES];
-+
-+/*
-+ * This lock is only held by dm_create and dm_set_name to avoid
-+ * race conditions where someone else may create a device with
-+ * the same name.
-+ */
-+static spinlock_t _create_lock = SPIN_LOCK_UNLOCKED;
-+
-+/* block device arrays */
-+static int _block_size[MAX_DEVICES];
-+static int _blksize_size[MAX_DEVICES];
-+static int _hardsect_size[MAX_DEVICES];
-+
-+static devfs_handle_t _dev_dir;
-+
-+static int request(request_queue_t * q, int rw, struct buffer_head *bh);
-+static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb);
-+
-+/*
-+ * Protect the mapped_devices referenced from _dev[]
-+ */
-+struct mapped_device *dm_get_r(int minor)
-+{
-+ struct mapped_device *md;
-+
-+ if (minor >= MAX_DEVICES)
-+ return NULL;
-+
-+ down_read(_dev_locks + minor);
-+ md = _devs[minor];
-+ if (!md)
-+ up_read(_dev_locks + minor);
-+ return md;
-+}
-+
-+struct mapped_device *dm_get_w(int minor)
-+{
-+ struct mapped_device *md;
-+
-+ if (minor >= MAX_DEVICES)
-+ return NULL;
-+
-+ down_write(_dev_locks + minor);
-+ md = _devs[minor];
-+ if (!md)
-+ up_write(_dev_locks + minor);
-+ return md;
-+}
-+
-+static int namecmp(struct mapped_device *md, const char *name, int nametype)
-+{
-+ switch (nametype) {
-+ case DM_LOOKUP_BY_NAME:
-+ return strcmp(md->name, name);
-+ break;
-+
-+ case DM_LOOKUP_BY_UUID:
-+ if (!md->uuid)
-+ return -1; /* never equal */
-+
-+ return strcmp(md->uuid, name);
-+ break;
-+
-+ default:
-+ DMWARN("Unknown comparison type in namecmp: %d", nametype);
-+ BUG();
-+ }
-+
-+ return -1;
-+}
-+
-+/*
-+ * The interface (eg, ioctl) will probably access the devices
-+ * through these slow 'by name' locks, this needs improving at
-+ * some point if people start playing with *large* numbers of dm
-+ * devices.
-+ */
-+struct mapped_device *dm_get_name_r(const char *name, int nametype)
-+{
-+ int i;
-+ struct mapped_device *md;
-+
-+ for (i = 0; i < MAX_DEVICES; i++) {
-+ md = dm_get_r(i);
-+ if (md) {
-+ if (!namecmp(md, name, nametype))
-+ return md;
-+
-+ dm_put_r(md);
-+ }
-+ }
-+
-+ return NULL;
-+}
-+
-+struct mapped_device *dm_get_name_w(const char *name, int nametype)
-+{
-+ int i;
-+ struct mapped_device *md;
-+
-+ /*
-+ * To avoid getting write locks on all the devices we try
-+ * and promote a read lock to a write lock, this can
-+ * fail, in which case we just start again.
-+ */
-+
-+ restart:
-+ for (i = 0; i < MAX_DEVICES; i++) {
-+ md = dm_get_r(i);
-+ if (!md)
-+ continue;
-+
-+ if (namecmp(md, name, nametype)) {
-+ dm_put_r(md);
-+ continue;
-+ }
-+
-+ /* found it */
-+ dm_put_r(md);
-+
-+ md = dm_get_w(i);
-+ if (!md)
-+ goto restart;
-+
-+ if (namecmp(md, name, nametype)) {
-+ dm_put_w(md);
-+ goto restart;
-+ }
-+
-+ return md;
-+ }
-+
-+ return NULL;
-+}
-+
-+void dm_put_r(struct mapped_device *md)
-+{
-+ int minor = MINOR(md->dev);
-+
-+ if (minor >= MAX_DEVICES)
-+ return;
-+
-+ up_read(_dev_locks + minor);
-+}
-+
-+void dm_put_w(struct mapped_device *md)
-+{
-+ int minor = MINOR(md->dev);
-+
-+ if (minor >= MAX_DEVICES)
-+ return;
-+
-+ up_write(_dev_locks + minor);
-+}
-+
-+/*
-+ * Setup and tear down the driver
-+ */
-+static __init void init_locks(void)
-+{
-+ int i;
-+
-+ for (i = 0; i < MAX_DEVICES; i++)
-+ init_rwsem(_dev_locks + i);
-+}
-+
-+static __init int local_init(void)
-+{
-+ int r;
-+
-+ init_locks();
-+
-+ /* allocate a slab for the io-hooks */
-+ if (!_io_hook_cache &&
-+ !(_io_hook_cache = kmem_cache_create("dm io hooks",
-+ sizeof(struct io_hook),
-+ 0, 0, NULL, NULL)))
-+ return -ENOMEM;
-+
-+ _major = major;
-+ r = devfs_register_blkdev(_major, _name, &dm_blk_dops);
-+ if (r < 0) {
-+ DMERR("register_blkdev failed");
-+ kmem_cache_destroy(_io_hook_cache);
-+ return r;
-+ }
-+
-+ if (!_major)
-+ _major = r;
-+
-+ /* set up the arrays */
-+ read_ahead[_major] = DEFAULT_READ_AHEAD;
-+ blk_size[_major] = _block_size;
-+ blksize_size[_major] = _blksize_size;
-+ hardsect_size[_major] = _hardsect_size;
-+
-+ blk_queue_make_request(BLK_DEFAULT_QUEUE(_major), request);
-+
-+ _dev_dir = devfs_mk_dir(0, DM_DIR, NULL);
-+
-+ DMINFO("%s initialised: %s", _version, _email);
-+ return 0;
-+}
-+
-+static void local_exit(void)
-+{
-+ if (kmem_cache_destroy(_io_hook_cache))
-+ DMWARN("io_hooks still allocated during unregistration");
-+ _io_hook_cache = NULL;
-+
-+ if (devfs_unregister_blkdev(_major, _name) < 0)
-+ DMERR("devfs_unregister_blkdev failed");
-+
-+ read_ahead[_major] = 0;
-+ blk_size[_major] = NULL;
-+ blksize_size[_major] = NULL;
-+ hardsect_size[_major] = NULL;
-+ _major = 0;
-+
-+ DMINFO("%s cleaned up", _version);
-+}
-+
-+/*
-+ * We have a lot of init/exit functions, so it seems easier to
-+ * store them in an array. The disposable macro 'xx'
-+ * expands a prefix into a pair of function names.
-+ */
-+static struct {
-+ int (*init)(void);
-+ void (*exit)(void);
-+
-+} _inits[] = {
-+#define xx(n) {n ## _init, n ## _exit},
-+ xx(local)
-+ xx(dm_target)
-+ xx(dm_linear)
-+ xx(dm_stripe)
-+ xx(dm_snapshot)
-+ xx(dm_interface)
-+#undef xx
-+};
-+
-+static int __init dm_init(void)
-+{
-+ const int count = sizeof(_inits) / sizeof(*_inits);
-+
-+ int r, i;
-+
-+ for (i = 0; i < count; i++) {
-+ r = _inits[i].init();
-+ if (r)
-+ goto bad;
-+ }
-+
-+ return 0;
-+
-+ bad:
-+ while (i--)
-+ _inits[i].exit();
-+
-+ return r;
-+}
-+
-+static void __exit dm_exit(void)
-+{
-+ int i = sizeof(_inits) / sizeof(*_inits);
-+
-+ dm_destroy_all();
-+ while (i--)
-+ _inits[i].exit();
-+}
-+
-+/*
-+ * Block device functions
-+ */
-+static int dm_blk_open(struct inode *inode, struct file *file)
-+{
-+ struct mapped_device *md;
-+
-+ md = dm_get_w(MINOR(inode->i_rdev));
-+ if (!md)
-+ return -ENXIO;
-+
-+ md->use_count++;
-+ dm_put_w(md);
-+
-+ return 0;
-+}
-+
-+static int dm_blk_close(struct inode *inode, struct file *file)
-+{
-+ struct mapped_device *md;
-+
-+ md = dm_get_w(MINOR(inode->i_rdev));
-+ if (!md)
-+ return -ENXIO;
-+
-+ if (md->use_count < 1)
-+ DMWARN("incorrect reference count found in mapped_device");
-+
-+ md->use_count--;
-+ dm_put_w(md);
-+
-+ return 0;
-+}
-+
-+/* In 512-byte units */
-+#define VOLUME_SIZE(minor) (_block_size[(minor)] << 1)
-+
-+static int dm_blk_ioctl(struct inode *inode, struct file *file,
-+ uint command, unsigned long a)
-+{
-+ int minor = MINOR(inode->i_rdev);
-+ long size;
-+
-+ if (minor >= MAX_DEVICES)
-+ return -ENXIO;
-+
-+ switch (command) {
-+ case BLKSSZGET:
-+ case BLKBSZGET:
-+ case BLKROGET:
-+ case BLKROSET:
-+ case BLKRASET:
-+ case BLKRAGET:
-+ case BLKFLSBUF:
-+#if 0 /* Future stacking block device */
-+ case BLKELVSET:
-+ case BLKELVGET:
-+#endif
-+ return blk_ioctl(inode->i_rdev, command, a);
-+ break;
-+
-+ case BLKGETSIZE:
-+ size = VOLUME_SIZE(minor);
-+ if (copy_to_user((void *) a, &size, sizeof(long)))
-+ return -EFAULT;
-+ break;
-+
-+ case BLKGETSIZE64:
-+ size = VOLUME_SIZE(minor);
-+ if (put_user((u64) size, (u64 *) a))
-+ return -EFAULT;
-+ break;
-+
-+ case BLKRRPART:
-+ return -EINVAL;
-+
-+ case LV_BMAP:
-+ return dm_user_bmap(inode, (struct lv_bmap *) a);
-+
-+ default:
-+ DMWARN("unknown block ioctl 0x%x", command);
-+ return -EINVAL;
-+ }
-+
-+ return 0;
-+}
-+
-+static inline struct io_hook *alloc_io_hook(void)
-+{
-+ return kmem_cache_alloc(_io_hook_cache, GFP_NOIO);
-+}
-+
-+static inline void free_io_hook(struct io_hook *ih)
-+{
-+ kmem_cache_free(_io_hook_cache, ih);
-+}
-+
-+/*
-+ * FIXME: We need to decide if deferred_io's need
-+ * their own slab, I say no for now since they are
-+ * only used when the device is suspended.
-+ */
-+static inline struct deferred_io *alloc_deferred(void)
-+{
-+ return kmalloc(sizeof(struct deferred_io), GFP_NOIO);
-+}
-+
-+static inline void free_deferred(struct deferred_io *di)
-+{
-+ kfree(di);
-+}
-+
-+/*
-+ * Call a target's optional error function if an I/O failed.
-+ */
-+static inline int call_err_fn(struct io_hook *ih, struct buffer_head *bh)
-+{
-+ dm_err_fn err = ih->target->type->err;
-+
-+ if (err)
-+ return err(bh, ih->rw, ih->target->private);
-+
-+ return 0;
-+}
-+
-+/*
-+ * bh->b_end_io routine that decrements the pending count
-+ * and then calls the original bh->b_end_io fn.
-+ */
-+static void dec_pending(struct buffer_head *bh, int uptodate)
-+{
-+ struct io_hook *ih = bh->b_bdev_private;
-+
-+ if (!uptodate && call_err_fn(ih, bh))
-+ return;
-+
-+ if (atomic_dec_and_test(&ih->md->pending))
-+ /* nudge anyone waiting on suspend queue */
-+ wake_up(&ih->md->wait);
-+
-+ bh->b_end_io = ih->end_io;
-+ bh->b_bdev_private = ih->context;
-+ free_io_hook(ih);
-+
-+ bh->b_end_io(bh, uptodate);
-+}
-+
-+/*
-+ * Add the bh to the list of deferred io.
-+ */
-+static int queue_io(struct buffer_head *bh, int rw)
-+{
-+ struct deferred_io *di = alloc_deferred();
-+ struct mapped_device *md;
-+
-+ if (!di)
-+ return -ENOMEM;
-+
-+ md = dm_get_w(MINOR(bh->b_rdev));
-+ if (!md) {
-+ free_deferred(di);
-+ return -ENXIO;
-+ }
-+
-+ if (!md->suspended) {
-+ dm_put_w(md);
-+ free_deferred(di);
-+ return 1;
-+ }
-+
-+ di->bh = bh;
-+ di->rw = rw;
-+ di->next = md->deferred;
-+ md->deferred = di;
-+
-+ dm_put_w(md);
-+
-+ return 0; /* deferred successfully */
-+}
-+
-+/*
-+ * Do the bh mapping for a given leaf
-+ */
-+static inline int __map_buffer(struct mapped_device *md,
-+ struct buffer_head *bh, int rw, int leaf)
-+{
-+ int r;
-+ dm_map_fn fn;
-+ void *context;
-+ struct io_hook *ih = NULL;
-+ struct target *ti = md->map->targets + leaf;
-+
-+ fn = ti->type->map;
-+ context = ti->private;
-+
-+ ih = alloc_io_hook();
-+
-+ if (!ih)
-+ return -1;
-+
-+ ih->md = md;
-+ ih->rw = rw;
-+ ih->target = ti;
-+ ih->end_io = bh->b_end_io;
-+ ih->context = bh->b_bdev_private;
-+
-+ r = fn(bh, rw, context);
-+
-+ if (r > 0) {
-+ /* hook the end io request fn */
-+ atomic_inc(&md->pending);
-+ bh->b_end_io = dec_pending;
-+ bh->b_bdev_private = ih;
-+
-+ } else if (r == 0)
-+ /* we don't need to hook */
-+ free_io_hook(ih);
-+
-+ else if (r < 0) {
-+ free_io_hook(ih);
-+ return -1;
-+ }
-+
-+ return r;
-+}
-+
-+/*
-+ * Search the btree for the correct target.
-+ */
-+static inline int __find_node(struct dm_table *t, struct buffer_head *bh)
-+{
-+ int l, n = 0, k = 0;
-+ offset_t *node;
-+
-+ for (l = 0; l < t->depth; l++) {
-+ n = get_child(n, k);
-+ node = get_node(t, l, n);
-+
-+ for (k = 0; k < KEYS_PER_NODE; k++)
-+ if (node[k] >= bh->b_rsector)
-+ break;
-+ }
-+
-+ return (KEYS_PER_NODE * n) + k;
-+}
-+
-+static int request(request_queue_t * q, int rw, struct buffer_head *bh)
-+{
-+ struct mapped_device *md;
-+ int r, minor = MINOR(bh->b_rdev);
-+
-+ md = dm_get_r(minor);
-+ if (!md) {
-+ buffer_IO_error(bh);
-+ return 0;
-+ }
-+
-+ /*
-+ * If we're suspended we have to queue
-+ * this io for later.
-+ */
-+ while (md->suspended) {
-+ dm_put_r(md);
-+
-+ if (rw == READA)
-+ goto bad_no_lock;
-+
-+ r = queue_io(bh, rw);
-+
-+ if (r < 0)
-+ goto bad_no_lock;
-+
-+ else if (r == 0)
-+ return 0; /* deferred successfully */
-+
-+ /*
-+ * We're in a while loop, because someone could suspend
-+ * before we get to the following read lock.
-+ */
-+ md = dm_get_r(minor);
-+ if (!md) {
-+ buffer_IO_error(bh);
-+ return 0;
-+ }
-+ }
-+
-+ if ((r = __map_buffer(md, bh, rw, __find_node(md->map, bh))) < 0)
-+ goto bad;
-+
-+ dm_put_r(md);
-+ return r;
-+
-+ bad:
-+ dm_put_r(md);
-+
-+ bad_no_lock:
-+ buffer_IO_error(bh);
-+ return 0;
-+}
-+
-+static int check_dev_size(int minor, unsigned long block)
-+{
-+ /* FIXME: check this */
-+ unsigned long max_sector = (_block_size[minor] << 1) + 1;
-+ unsigned long sector = (block + 1) * (_blksize_size[minor] >> 9);
-+
-+ return (sector > max_sector) ? 0 : 1;
-+}
-+
-+/*
-+ * Creates a dummy buffer head and maps it (for lilo).
-+ */
-+static int do_bmap(kdev_t dev, unsigned long block,
-+ kdev_t * r_dev, unsigned long *r_block)
-+{
-+ struct mapped_device *md;
-+ struct buffer_head bh;
-+ int minor = MINOR(dev), r;
-+ struct target *t;
-+
-+ md = dm_get_r(minor);
-+ if (!md)
-+ return -ENXIO;
-+
-+ if (md->suspended) {
-+ dm_put_r(md);
-+ return -EPERM;
-+ }
-+
-+ if (!check_dev_size(minor, block)) {
-+ dm_put_r(md);
-+ return -EINVAL;
-+ }
-+
-+ /* setup dummy bh */
-+ memset(&bh, 0, sizeof(bh));
-+ bh.b_blocknr = block;
-+ bh.b_dev = bh.b_rdev = dev;
-+ bh.b_size = _blksize_size[minor];
-+ bh.b_rsector = block * (bh.b_size >> 9);
-+
-+ /* find target */
-+ t = md->map->targets + __find_node(md->map, &bh);
-+
-+ /* do the mapping */
-+ r = t->type->map(&bh, READ, t->private);
-+
-+ *r_dev = bh.b_rdev;
-+ *r_block = bh.b_rsector / (bh.b_size >> 9);
-+
-+ dm_put_r(md);
-+ return r;
-+}
-+
-+/*
-+ * Marshals arguments and results between user and kernel space.
-+ */
-+static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb)
-+{
-+ unsigned long block, r_block;
-+ kdev_t r_dev;
-+ int r;
-+
-+ if (get_user(block, &lvb->lv_block))
-+ return -EFAULT;
-+
-+ if ((r = do_bmap(inode->i_rdev, block, &r_dev, &r_block)))
-+ return r;
-+
-+ if (put_user(kdev_t_to_nr(r_dev), &lvb->lv_dev) ||
-+ put_user(r_block, &lvb->lv_block))
-+ return -EFAULT;
-+
-+ return 0;
-+}
-+
-+/*
-+ * See if the device with a specific minor # is free. The write
-+ * lock is held when it returns successfully.
-+ */
-+static inline int specific_dev(int minor, struct mapped_device *md)
-+{
-+ if (minor >= MAX_DEVICES) {
-+ DMWARN("request for a mapped_device beyond MAX_DEVICES (%d)",
-+ MAX_DEVICES);
-+ return -1;
-+ }
-+
-+ down_write(_dev_locks + minor);
-+ if (_devs[minor]) {
-+ /* in use */
-+ up_write(_dev_locks + minor);
-+ return -1;
-+ }
-+
-+ return minor;
-+}
-+
-+/*
-+ * Find the first free device. Again the write lock is held on
-+ * success.
-+ */
-+static int any_old_dev(struct mapped_device *md)
-+{
-+ int i;
-+
-+ for (i = 0; i < MAX_DEVICES; i++)
-+ if (specific_dev(i, md) != -1)
-+ return i;
-+
-+ return -1;
-+}
-+
-+/*
-+ * Allocate and initialise a blank device.
-+ * Caller must ensure uuid is null-terminated.
-+ * Device is returned with a write lock held.
-+ */
-+static struct mapped_device *alloc_dev(const char *name, const char *uuid,
-+ int minor)
-+{
-+ struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL);
-+ int len;
-+
-+ if (!md) {
-+ DMWARN("unable to allocate device, out of memory.");
-+ return NULL;
-+ }
-+
-+ memset(md, 0, sizeof(*md));
-+
-+ /*
-+ * This grabs the write lock if it succeeds.
-+ */
-+ minor = (minor < 0) ? any_old_dev(md) : specific_dev(minor, md);
-+ if (minor < 0) {
-+ kfree(md);
-+ return NULL;
-+ }
-+
-+ md->dev = MKDEV(_major, minor);
-+ md->suspended = 0;
-+
-+ strncpy(md->name, name, sizeof(md->name) - 1);
-+ md->name[sizeof(md->name) - 1] = '\0';
-+
-+ /*
-+ * Copy in the uuid.
-+ */
-+ if (uuid && *uuid) {
-+ len = strlen(uuid) + 1;
-+ if (!(md->uuid = kmalloc(len, GFP_KERNEL))) {
-+ DMWARN("unable to allocate uuid - out of memory.");
-+ kfree(md);
-+ return NULL;
-+ }
-+ strcpy(md->uuid, uuid);
-+ }
-+
-+ init_waitqueue_head(&md->wait);
-+ return md;
-+}
-+
-+static int __register_device(struct mapped_device *md)
-+{
-+ md->devfs_entry =
-+ devfs_register(_dev_dir, md->name, DEVFS_FL_CURRENT_OWNER,
-+ MAJOR(md->dev), MINOR(md->dev),
-+ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP,
-+ &dm_blk_dops, NULL);
-+
-+ return 0;
-+}
-+
-+static int __unregister_device(struct mapped_device *md)
-+{
-+ devfs_unregister(md->devfs_entry);
-+ return 0;
-+}
-+
-+/*
-+ * The hardsect size for a mapped device is the smallest hardsect size
-+ * from the devices it maps onto.
-+ */
-+static int __find_hardsect_size(struct list_head *devices)
-+{
-+ int result = INT_MAX, size;
-+ struct list_head *tmp;
-+
-+ list_for_each(tmp, devices) {
-+ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list);
-+ size = get_hardsect_size(dd->dev);
-+ if (size < result)
-+ result = size;
-+ }
-+ return result;
-+}
-+
-+/*
-+ * Bind a table to the device.
-+ */
-+static int __bind(struct mapped_device *md, struct dm_table *t)
-+{
-+ int minor = MINOR(md->dev);
-+
-+ md->map = t;
-+
-+ if (!t->num_targets) {
-+ _block_size[minor] = 0;
-+ _blksize_size[minor] = BLOCK_SIZE;
-+ _hardsect_size[minor] = 0;
-+ return 0;
-+ }
-+
-+ /* in k */
-+ _block_size[minor] = (t->highs[t->num_targets - 1] + 1) >> 1;
-+
-+ _blksize_size[minor] = BLOCK_SIZE;
-+ _hardsect_size[minor] = __find_hardsect_size(&t->devices);
-+ register_disk(NULL, md->dev, 1, &dm_blk_dops, _block_size[minor]);
-+
-+ return 0;
-+}
-+
-+static void __unbind(struct mapped_device *md)
-+{
-+ int minor = MINOR(md->dev);
-+
-+ dm_table_destroy(md->map);
-+ md->map = NULL;
-+
-+ _block_size[minor] = 0;
-+ _blksize_size[minor] = 0;
-+ _hardsect_size[minor] = 0;
-+}
-+
-+static int check_name(const char *name)
-+{
-+ struct mapped_device *md;
-+
-+ if (strchr(name, '/') || strlen(name) > DM_NAME_LEN) {
-+ DMWARN("invalid device name");
-+ return -1;
-+ }
-+
-+ md = dm_get_name_r(name, DM_LOOKUP_BY_NAME);
-+ if (md) {
-+ dm_put_r(md);
-+ DMWARN("device name already in use");
-+ return -1;
-+ }
-+
-+ return 0;
-+}
-+
-+static int check_uuid(const char *uuid)
-+{
-+ struct mapped_device *md;
-+
-+ if (uuid) {
-+ md = dm_get_name_r(uuid, DM_LOOKUP_BY_UUID);
-+ if (md) {
-+ dm_put_r(md);
-+ DMWARN("device uuid already in use");
-+ return -1;
-+ }
-+ }
-+
-+ return 0;
-+}
-+
-+/*
-+ * Constructor for a new device.
-+ */
-+int dm_create(const char *name, const char *uuid, int minor, int ro,
-+ struct dm_table *table)
-+{
-+ int r;
-+ struct mapped_device *md;
-+
-+ spin_lock(&_create_lock);
-+ if (check_name(name) || check_uuid(uuid)) {
-+ spin_unlock(&_create_lock);
-+ return -EINVAL;
-+ }
-+
-+ md = alloc_dev(name, uuid, minor);
-+ if (!md) {
-+ spin_unlock(&_create_lock);
-+ return -ENXIO;
-+ }
-+ minor = MINOR(md->dev);
-+ _devs[minor] = md;
-+
-+ r = __register_device(md);
-+ if (r)
-+ goto err;
-+
-+ r = __bind(md, table);
-+ if (r)
-+ goto err;
-+
-+ dm_set_ro(md, ro);
-+
-+ spin_unlock(&_create_lock);
-+ dm_put_w(md);
-+ return 0;
-+
-+ err:
-+ _devs[minor] = NULL;
-+ if (md->uuid)
-+ kfree(md->uuid);
-+
-+ dm_put_w(md);
-+ kfree(md);
-+ spin_unlock(&_create_lock);
-+ return r;
-+}
-+
-+/*
-+ * Renames the device. No lock held.
-+ */
-+int dm_set_name(const char *name, int nametype, const char *newname)
-+{
-+ int r;
-+ struct mapped_device *md;
-+
-+ spin_lock(&_create_lock);
-+ if (check_name(newname) < 0) {
-+ spin_unlock(&_create_lock);
-+ return -EINVAL;
-+ }
-+
-+ md = dm_get_name_w(name, nametype);
-+ if (!md) {
-+ spin_unlock(&_create_lock);
-+ return -ENXIO;
-+ }
-+
-+ r = __unregister_device(md);
-+ if (r)
-+ goto out;
-+
-+ strcpy(md->name, newname);
-+ r = __register_device(md);
-+
-+ out:
-+ dm_put_w(md);
-+ spin_unlock(&_create_lock);
-+ return r;
-+}
-+
-+/*
-+ * Destructor for the device. You cannot destroy an open
-+ * device. Write lock must be held before calling.
-+ * Caller must dm_put_w(md) then kfree(md) if call was successful.
-+ */
-+int dm_destroy(struct mapped_device *md)
-+{
-+ int minor, r;
-+
-+ if (md->use_count)
-+ return -EPERM;
-+
-+ r = __unregister_device(md);
-+ if (r)
-+ return r;
-+
-+ minor = MINOR(md->dev);
-+ _devs[minor] = NULL;
-+ __unbind(md);
-+
-+ if (md->uuid)
-+ kfree(md->uuid);
-+
-+ return 0;
-+}
-+
-+/*
-+ * Destroy all devices - except open ones
-+ */
-+void dm_destroy_all(void)
-+{
-+ int i, some_destroyed, r;
-+ struct mapped_device *md;
-+
-+ do {
-+ some_destroyed = 0;
-+ for (i = 0; i < MAX_DEVICES; i++) {
-+ md = dm_get_w(i);
-+ if (!md)
-+ continue;
-+
-+ r = dm_destroy(md);
-+ dm_put_w(md);
-+
-+ if (!r) {
-+ kfree(md);
-+ some_destroyed = 1;
-+ }
-+ }
-+ } while (some_destroyed);
-+}
-+
-+/*
-+ * Sets or clears the read-only flag for the device. Write lock
-+ * must be held.
-+ */
-+void dm_set_ro(struct mapped_device *md, int ro)
-+{
-+ md->read_only = ro;
-+ set_device_ro(md->dev, ro);
-+}
-+
-+/*
-+ * A target is notifying us of some event
-+ */
-+void dm_notify(void *target)
-+{
-+}
-+
-+/*
-+ * Requeue the deferred buffer_heads by calling generic_make_request.
-+ */
-+static void flush_deferred_io(struct deferred_io *c)
-+{
-+ struct deferred_io *n;
-+
-+ while (c) {
-+ n = c->next;
-+ generic_make_request(c->rw, c->bh);
-+ free_deferred(c);
-+ c = n;
-+ }
-+}
-+
-+/*
-+ * Swap in a new table (destroying old one). Write lock must be
-+ * held.
-+ */
-+int dm_swap_table(struct mapped_device *md, struct dm_table *table)
-+{
-+ int r;
-+
-+ /* device must be suspended */
-+ if (!md->suspended)
-+ return -EPERM;
-+
-+ __unbind(md);
-+
-+ r = __bind(md, table);
-+ if (r)
-+ return r;
-+
-+ return 0;
-+}
-+
-+/*
-+ * We need to be able to change a mapping table under a mounted
-+ * filesystem. for example we might want to move some data in
-+ * the background. Before the table can be swapped with
-+ * dm_bind_table, dm_suspend must be called to flush any in
-+ * flight buffer_heads and ensure that any further io gets
-+ * deferred. Write lock must be held.
-+ */
-+int dm_suspend(struct mapped_device *md)
-+{
-+ int minor = MINOR(md->dev);
-+ DECLARE_WAITQUEUE(wait, current);
-+
-+ if (md->suspended)
-+ return -EINVAL;
-+
-+ md->suspended = 1;
-+ dm_put_w(md);
-+
-+ /* wait for all the pending io to flush */
-+ add_wait_queue(&md->wait, &wait);
-+ current->state = TASK_UNINTERRUPTIBLE;
-+ do {
-+ md = dm_get_w(minor);
-+ if (!md) {
-+ /* Caller expects to free this lock. Yuck. */
-+ down_write(_dev_locks + minor);
-+ return -ENXIO;
-+ }
-+
-+ if (!atomic_read(&md->pending))
-+ break;
-+
-+ dm_put_w(md);
-+ schedule();
-+
-+ } while (1);
-+
-+ current->state = TASK_RUNNING;
-+ remove_wait_queue(&md->wait, &wait);
-+
-+ return 0;
-+}
-+
-+int dm_resume(struct mapped_device *md)
-+{
-+ int minor = MINOR(md->dev);
-+ struct deferred_io *def;
-+
-+ if (!md->suspended || !md->map->num_targets)
-+ return -EINVAL;
-+
-+ md->suspended = 0;
-+ def = md->deferred;
-+ md->deferred = NULL;
-+
-+ dm_put_w(md);
-+ flush_deferred_io(def);
-+ run_task_queue(&tq_disk);
-+
-+ if (!dm_get_w(minor)) {
-+ /* FIXME: yuck */
-+ down_write(_dev_locks + minor);
-+ return -ENXIO;
-+ }
-+
-+ return 0;
-+}
-+
-+struct block_device_operations dm_blk_dops = {
-+ open: dm_blk_open,
-+ release: dm_blk_close,
-+ ioctl: dm_blk_ioctl,
-+ owner: THIS_MODULE
-+};
-+
-+/*
-+ * module hooks
-+ */
-+module_init(dm_init);
-+module_exit(dm_exit);
-+
-+MODULE_PARM(major, "i");
-+MODULE_PARM_DESC(major, "The major number of the device mapper");
-+MODULE_DESCRIPTION(DM_NAME " driver");
-+MODULE_AUTHOR("Joe Thornber <thornber@sistina.com>");
-+MODULE_LICENSE("GPL");
-diff -ruN linux-2.4.19-pre8/drivers/md/dm.h linux/drivers/md/dm.h
---- linux-2.4.19-pre8/drivers/md/dm.h Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm.h Mon May 20 15:02:13 2002
-@@ -0,0 +1,220 @@
-+/*
-+ * Internal header file for device mapper
-+ *
-+ * Copyright (C) 2001 Sistina Software
-+ *
-+ * This file is released under the LGPL.
-+ */
-+
-+#ifndef DM_INTERNAL_H
-+#define DM_INTERNAL_H
-+
-+#include <linux/config.h>
-+#include <linux/version.h>
-+#include <linux/major.h>
-+#include <linux/iobuf.h>
-+#include <linux/module.h>
-+#include <linux/fs.h>
-+#include <linux/slab.h>
-+#include <linux/vmalloc.h>
-+#include <linux/compatmac.h>
-+#include <linux/cache.h>
-+#include <linux/devfs_fs_kernel.h>
-+#include <linux/ctype.h>
-+#include <linux/device-mapper.h>
-+#include <linux/list.h>
-+#include <linux/init.h>
-+
-+#define DM_NAME "device-mapper" /* Name for messaging */
-+#define MAX_DEPTH 16
-+#define NODE_SIZE L1_CACHE_BYTES
-+#define KEYS_PER_NODE (NODE_SIZE / sizeof(offset_t))
-+#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
-+#define MAX_ARGS 32
-+#define MAX_DEVICES 256
-+
-+/*
-+ * List of devices that a metadevice uses and should open/close.
-+ */
-+struct dm_dev {
-+ atomic_t count;
-+ struct list_head list;
-+
-+ kdev_t dev;
-+ struct block_device *bd;
-+};
-+
-+/*
-+ * I/O that had to be deferred while we were suspended
-+ */
-+struct deferred_io {
-+ int rw;
-+ struct buffer_head *bh;
-+ struct deferred_io *next;
-+};
-+
-+/*
-+ * Btree leaf - this does the actual mapping
-+ */
-+struct target {
-+ struct target_type *type;
-+ void *private;
-+};
-+
-+/*
-+ * The btree
-+ */
-+struct dm_table {
-+ /* btree table */
-+ int depth;
-+ int counts[MAX_DEPTH]; /* in nodes */
-+ offset_t *index[MAX_DEPTH];
-+
-+ int num_targets;
-+ int num_allocated;
-+ offset_t *highs;
-+ struct target *targets;
-+
-+ /* a list of devices used by this table */
-+ struct list_head devices;
-+};
-+
-+/*
-+ * The actual device struct
-+ */
-+struct mapped_device {
-+ kdev_t dev;
-+ char name[DM_NAME_LEN];
-+ char *uuid;
-+
-+ int use_count;
-+ int suspended;
-+ int read_only;
-+
-+ /* a list of io's that arrived while we were suspended */
-+ atomic_t pending;
-+ wait_queue_head_t wait;
-+ struct deferred_io *deferred;
-+
-+ struct dm_table *map;
-+
-+ /* used by dm-fs.c */
-+ devfs_handle_t devfs_entry;
-+};
-+
-+extern struct block_device_operations dm_blk_dops;
-+
-+/* dm-target.c */
-+int dm_target_init(void);
-+struct target_type *dm_get_target_type(const char *name);
-+void dm_put_target_type(struct target_type *t);
-+void dm_target_exit(void);
-+
-+/*
-+ * Destructively splits argument list to pass to ctr.
-+ */
-+int split_args(int max, int *argc, char **argv, char *input);
-+
-+/* dm.c */
-+struct mapped_device *dm_get_r(int minor);
-+struct mapped_device *dm_get_w(int minor);
-+
-+/*
-+ * There are two ways to lookup a device.
-+ */
-+enum {
-+ DM_LOOKUP_BY_NAME,
-+ DM_LOOKUP_BY_UUID
-+};
-+
-+struct mapped_device *dm_get_name_r(const char *name, int nametype);
-+struct mapped_device *dm_get_name_w(const char *name, int nametype);
-+
-+void dm_put_r(struct mapped_device *md);
-+void dm_put_w(struct mapped_device *md);
-+
-+/*
-+ * Call with no lock.
-+ */
-+int dm_create(const char *name, const char *uuid, int minor, int ro,
-+ struct dm_table *table);
-+int dm_set_name(const char *name, int nametype, const char *newname);
-+void dm_destroy_all(void);
-+
-+/*
-+ * You must have the write lock before calling the remaining md
-+ * methods.
-+ */
-+int dm_destroy(struct mapped_device *md);
-+void dm_set_ro(struct mapped_device *md, int ro);
-+
-+/*
-+ * The device must be suspended before calling this method.
-+ */
-+int dm_swap_table(struct mapped_device *md, struct dm_table *t);
-+
-+/*
-+ * A device can still be used while suspended, but I/O is deferred.
-+ */
-+int dm_suspend(struct mapped_device *md);
-+int dm_resume(struct mapped_device *md);
-+
-+/*
-+ * Event notification
-+ */
-+void dm_notify(void *target);
-+
-+/* dm-table.c */
-+int dm_table_create(struct dm_table **result);
-+void dm_table_destroy(struct dm_table *t);
-+
-+int dm_table_add_target(struct dm_table *t, offset_t highs,
-+ struct target_type *type, void *private);
-+int dm_table_complete(struct dm_table *t);
-+
-+/* Snapshots */
-+int dm_snapshot_init(void);
-+void dm_snapshot_exit(void);
-+
-+/* dm-mirror.c */
-+int dm_mirror_init(void);
-+void dm_mirror_exit(void);
-+
-+#define DMWARN(f, x...) printk(KERN_WARNING DM_NAME ": " f "\n" , ## x)
-+#define DMERR(f, x...) printk(KERN_ERR DM_NAME ": " f "\n" , ## x)
-+#define DMINFO(f, x...) printk(KERN_INFO DM_NAME ": " f "\n" , ## x)
-+
-+/*
-+ * Calculate the index of the child node of the n'th node k'th key.
-+ */
-+static inline int get_child(int n, int k)
-+{
-+ return (n * CHILDREN_PER_NODE) + k;
-+}
-+
-+/*
-+ * Return the n'th node of level l from table t.
-+ */
-+static inline offset_t *get_node(struct dm_table *t, int l, int n)
-+{
-+ return t->index[l] + (n * KEYS_PER_NODE);
-+}
-+
-+/*
-+ * The device-mapper can be driven through one of two interfaces;
-+ * ioctl or filesystem, depending which patch you have applied.
-+ */
-+int __init dm_interface_init(void);
-+void dm_interface_exit(void);
-+
-+/*
-+ * Targets for linear and striped mappings
-+ */
-+
-+int dm_linear_init(void);
-+void dm_linear_exit(void);
-+
-+int dm_stripe_init(void);
-+void dm_stripe_exit(void);
-+
-+#endif
-diff -ruN linux-2.4.19-pre8/drivers/md/kcopyd.c linux/drivers/md/kcopyd.c
---- linux-2.4.19-pre8/drivers/md/kcopyd.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/kcopyd.c Mon May 20 14:18:59 2002
-@@ -0,0 +1,770 @@
-+/*
-+ * Copyright (C) 2002 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#include <linux/config.h>
-+#include <linux/module.h>
-+#include <linux/init.h>
-+#include <linux/slab.h>
-+#include <linux/list.h>
-+#include <linux/fs.h>
-+#include <linux/blkdev.h>
-+#include <linux/device-mapper.h>
-+#include <linux/mempool.h>
-+#include <asm/atomic.h>
-+#include <linux/pagemap.h>
-+#include <linux/locks.h>
-+
-+#include "kcopyd.h"
-+
-+/* FIXME: this is only needed for the DMERR macros */
-+#include "dm.h"
-+
-+/*
-+ * Hard sector size used all over the kernel.
-+ */
-+#define SECTOR_SIZE 512
-+#define SECTOR_SHIFT 9
-+
-+static void wake_kcopyd(void);
-+
-+/*-----------------------------------------------------------------
-+ * We reserve our own pool of preallocated pages that are
-+ * only used for kcopyd io.
-+ *---------------------------------------------------------------*/
-+
-+/*
-+ * FIXME: This should be configurable.
-+ */
-+#define NUM_PAGES 512
-+
-+static DECLARE_MUTEX(_pages_lock);
-+static int _num_free_pages;
-+static struct page *_pages_array[NUM_PAGES];
-+static DECLARE_MUTEX(start_lock);
-+
-+static int init_pages(void)
-+{
-+ int i;
-+ struct page *p;
-+
-+ for (i = 0; i < NUM_PAGES; i++) {
-+ p = alloc_page(GFP_KERNEL);
-+ if (!p)
-+ goto bad;
-+
-+ LockPage(p);
-+ _pages_array[i] = p;
-+ }
-+
-+ _num_free_pages = NUM_PAGES;
-+ return 0;
-+
-+ bad:
-+ while (i--)
-+ __free_page(_pages_array[i]);
-+ return -ENOMEM;
-+}
-+
-+static void exit_pages(void)
-+{
-+ int i;
-+ struct page *p;
-+
-+ for (i = 0; i < NUM_PAGES; i++) {
-+ p = _pages_array[i];
-+ UnlockPage(p);
-+ __free_page(p);
-+ }
-+
-+ _num_free_pages = 0;
-+}
-+
-+static int kcopyd_get_pages(int num, struct page **result)
-+{
-+ int i;
-+
-+ down(&_pages_lock);
-+ if (_num_free_pages < num) {
-+ up(&_pages_lock);
-+ return -ENOMEM;
-+ }
-+
-+ for (i = 0; i < num; i++) {
-+ _num_free_pages--;
-+ result[i] = _pages_array[_num_free_pages];
-+ }
-+ up(&_pages_lock);
-+
-+ return 0;
-+}
-+
-+static void kcopyd_free_pages(int num, struct page **result)
-+{
-+ int i;
-+
-+ down(&_pages_lock);
-+ for (i = 0; i < num; i++)
-+ _pages_array[_num_free_pages++] = result[i];
-+ up(&_pages_lock);
-+}
-+
-+/*-----------------------------------------------------------------
-+ * We keep our own private pool of buffer_heads. These are just
-+ * held in a list on the b_reqnext field.
-+ *---------------------------------------------------------------*/
-+
-+/*
-+ * Make sure we have enough buffers to always keep the pages
-+ * occupied. So we assume the worst case scenario where blocks
-+ * are the size of a single sector.
-+ */
-+#define NUM_BUFFERS NUM_PAGES * (PAGE_SIZE / SECTOR_SIZE)
-+
-+static spinlock_t _buffer_lock = SPIN_LOCK_UNLOCKED;
-+static struct buffer_head *_all_buffers;
-+static struct buffer_head *_free_buffers;
-+
-+static int init_buffers(void)
-+{
-+ int i;
-+ struct buffer_head *buffers;
-+ size_t s = sizeof(struct buffer_head) * NUM_BUFFERS;
-+
-+ /*
-+ * FIXME: this should be a vmalloc.
-+ */
-+ buffers = vmalloc(s);
-+ if (!buffers) {
-+ DMWARN("Couldn't allocate buffer heads.");
-+ return -ENOMEM;
-+ }
-+
-+ memset(buffers, 0, s);
-+ for (i = 0; i < NUM_BUFFERS; i++) {
-+ if (i < NUM_BUFFERS - 1)
-+ buffers[i].b_reqnext = &buffers[i + 1];
-+ init_waitqueue_head(&buffers[i].b_wait);
-+ INIT_LIST_HEAD(&buffers[i].b_inode_buffers);
-+ }
-+
-+ _all_buffers = _free_buffers = buffers;
-+ return 0;
-+}
-+
-+static void exit_buffers(void)
-+{
-+ vfree(_all_buffers);
-+}
-+
-+static struct buffer_head *alloc_buffer(void)
-+{
-+ struct buffer_head *r;
-+ int flags;
-+
-+ spin_lock_irqsave(&_buffer_lock, flags);
-+
-+ if (!_free_buffers)
-+ r = NULL;
-+ else {
-+ r = _free_buffers;
-+ _free_buffers = _free_buffers->b_reqnext;
-+ r->b_reqnext = NULL;
-+ }
-+
-+ spin_unlock_irqrestore(&_buffer_lock, flags);
-+
-+ return r;
-+}
-+
-+/*
-+ * Only called from interrupt context.
-+ */
-+static void free_buffer(struct buffer_head *bh)
-+{
-+ int flags;
-+
-+ spin_lock_irqsave(&_buffer_lock, flags);
-+ bh->b_reqnext = _free_buffers;
-+ _free_buffers = bh;
-+ spin_unlock_irqrestore(&_buffer_lock, flags);
-+}
-+
-+/*-----------------------------------------------------------------
-+ * kcopyd_jobs need to be allocated by the *clients* of kcopyd,
-+ * for this reason we use a mempool to prevent the client from
-+ * ever having to do io (which could cause a
-+ * deadlock).
-+ *---------------------------------------------------------------*/
-+#define MIN_JOBS NUM_PAGES
-+
-+static kmem_cache_t *_job_cache = NULL;
-+static mempool_t *_job_pool = NULL;
-+
-+/*
-+ * We maintain three lists of jobs:
-+ *
-+ * i) jobs waiting for pages
-+ * ii) jobs that have pages, and are waiting for the io to be issued.
-+ * iii) jobs that have completed.
-+ *
-+ * All three of these are protected by job_lock.
-+ */
-+
-+static spinlock_t _job_lock = SPIN_LOCK_UNLOCKED;
-+
-+static LIST_HEAD(_complete_jobs);
-+static LIST_HEAD(_io_jobs);
-+static LIST_HEAD(_pages_jobs);
-+
-+static int init_jobs(void)
-+{
-+ INIT_LIST_HEAD(&_complete_jobs);
-+ INIT_LIST_HEAD(&_io_jobs);
-+ INIT_LIST_HEAD(&_pages_jobs);
-+
-+ _job_cache = kmem_cache_create("kcopyd-jobs", sizeof(struct kcopyd_job),
-+ __alignof__(struct kcopyd_job),
-+ 0, NULL, NULL);
-+ if (!_job_cache)
-+ return -ENOMEM;
-+
-+ _job_pool = mempool_create(MIN_JOBS, mempool_alloc_slab,
-+ mempool_free_slab, _job_cache);
-+ if (!_job_pool) {
-+ kmem_cache_destroy(_job_cache);
-+ return -ENOMEM;
-+ }
-+
-+ return 0;
-+}
-+
-+static void exit_jobs(void)
-+{
-+ mempool_destroy(_job_pool);
-+ kmem_cache_destroy(_job_cache);
-+}
-+
-+struct kcopyd_job *kcopyd_alloc_job(void)
-+{
-+ struct kcopyd_job *job;
-+
-+ job = mempool_alloc(_job_pool, GFP_KERNEL);
-+ if (!job)
-+ return NULL;
-+
-+ memset(job, 0, sizeof(*job));
-+ return job;
-+}
-+
-+void kcopyd_free_job(struct kcopyd_job *job)
-+{
-+ mempool_free(job, _job_pool);
-+}
-+
-+/*
-+ * Functions to push and pop a job onto the head of a given job
-+ * list.
-+ */
-+static inline struct kcopyd_job *pop(struct list_head *jobs)
-+{
-+ struct kcopyd_job *job = NULL;
-+ int flags;
-+
-+ spin_lock_irqsave(&_job_lock, flags);
-+
-+ if (!list_empty(jobs)) {
-+ job = list_entry(jobs->next, struct kcopyd_job, list);
-+ list_del(&job->list);
-+ }
-+ spin_unlock_irqrestore(&_job_lock, flags);
-+
-+ return job;
-+}
-+
-+static inline void push(struct list_head *jobs, struct kcopyd_job *job)
-+{
-+ int flags;
-+
-+ spin_lock_irqsave(&_job_lock, flags);
-+ list_add(&job->list, jobs);
-+ spin_unlock_irqrestore(&_job_lock, flags);
-+}
-+
-+/*
-+ * Completion function for one of our buffers.
-+ */
-+static void end_bh(struct buffer_head *bh, int uptodate)
-+{
-+ struct kcopyd_job *job = bh->b_private;
-+
-+ mark_buffer_uptodate(bh, uptodate);
-+ unlock_buffer(bh);
-+
-+ if (!uptodate)
-+ job->err = -EIO;
-+
-+ /* are we the last ? */
-+ if (atomic_dec_and_test(&job->nr_incomplete)) {
-+ push(&_complete_jobs, job);
-+ wake_kcopyd();
-+ }
-+
-+ free_buffer(bh);
-+}
-+
-+static void dispatch_bh(struct kcopyd_job *job,
-+ struct buffer_head *bh, int block)
-+{
-+ int p;
-+
-+ /*
-+ * Add in the job offset
-+ */
-+ block += job->offset >> job->block_shift;
-+ bh->b_blocknr = (job->disk.sector >> job->block_shift) + block;
-+
-+ p = block >> job->bpp_shift;
-+ block &= job->bpp_mask;
-+
-+ bh->b_dev = B_FREE;
-+ bh->b_size = job->block_size;
-+ set_bh_page(bh, job->pages[p],
-+ (block << job->block_shift) << SECTOR_SHIFT);
-+ bh->b_this_page = bh;
-+
-+ init_buffer(bh, end_bh, job);
-+
-+ bh->b_dev = job->disk.dev;
-+ bh->b_state = ((1 << BH_Mapped) | (1 << BH_Lock) | (1 << BH_Req));
-+
-+ set_bit(BH_Uptodate, &bh->b_state);
-+ if (job->rw == WRITE)
-+ clear_bit(BH_Dirty, &bh->b_state);
-+
-+ submit_bh(job->rw, bh);
-+}
-+
-+/*
-+ * These three functions process 1 item from the corresponding
-+ * job list.
-+ *
-+ * They return:
-+ * < 0: error
-+ * 0: success
-+ * > 0: can't process yet.
-+ */
-+static int run_complete_job(struct kcopyd_job *job)
-+{
-+ job->callback(job);
-+ return 0;
-+}
-+
-+/*
-+ * Request io on as many buffer heads as we can currently get for
-+ * a particular job.
-+ */
-+static int run_io_job(struct kcopyd_job *job)
-+{
-+ unsigned int block;
-+ struct buffer_head *bh;
-+
-+ for (block = atomic_read(&job->nr_requested);
-+ block < job->nr_blocks; block++) {
-+ bh = alloc_buffer();
-+ if (!bh)
-+ break;
-+
-+ atomic_inc(&job->nr_requested);
-+ dispatch_bh(job, bh, block);
-+ }
-+
-+ return (block == job->nr_blocks) ? 0 : 1;
-+}
-+
-+static int run_pages_job(struct kcopyd_job *job)
-+{
-+ int r;
-+
-+ job->nr_pages = (job->disk.count + job->offset) /
-+ (PAGE_SIZE / SECTOR_SIZE);
-+ r = kcopyd_get_pages(job->nr_pages, job->pages);
-+ if (!r) {
-+ /* this job is ready for io */
-+ push(&_io_jobs, job);
-+ return 0;
-+ }
-+
-+ if (r == -ENOMEM)
-+ /* can complete now */
-+ return 1;
-+
-+ return r;
-+}
-+
-+/*
-+ * Run through a list for as long as possible. Returns the count
-+ * of successful jobs.
-+ */
-+static int process_jobs(struct list_head *jobs, int (*fn) (struct kcopyd_job *))
-+{
-+ struct kcopyd_job *job;
-+ int r, count = 0;
-+
-+ while ((job = pop(jobs))) {
-+
-+ r = fn(job);
-+
-+ if (r < 0) {
-+ /* error this rogue job */
-+ job->err = r;
-+ push(&_complete_jobs, job);
-+ break;
-+ }
-+
-+ if (r > 0) {
-+ /*
-+ * We couldn't service this job ATM, so
-+ * push this job back onto the list.
-+ */
-+ push(jobs, job);
-+ break;
-+ }
-+
-+ count++;
-+ }
-+
-+ return count;
-+}
-+
-+/*
-+ * kcopyd does this every time it's woken up.
-+ */
-+static void do_work(void)
-+{
-+ int count;
-+
-+ /*
-+ * We loop round until there is no more work to do.
-+ */
-+ do {
-+ count = process_jobs(&_complete_jobs, run_complete_job);
-+ count += process_jobs(&_io_jobs, run_io_job);
-+ count += process_jobs(&_pages_jobs, run_pages_job);
-+
-+ } while (count);
-+
-+ run_task_queue(&tq_disk);
-+}
-+
-+/*-----------------------------------------------------------------
-+ * The daemon
-+ *---------------------------------------------------------------*/
-+static atomic_t _kcopyd_must_die;
-+static DECLARE_MUTEX(_run_lock);
-+static DECLARE_WAIT_QUEUE_HEAD(_job_queue);
-+
-+static int kcopyd(void *arg)
-+{
-+ DECLARE_WAITQUEUE(wq, current);
-+
-+ daemonize();
-+ strcpy(current->comm, "kcopyd");
-+ atomic_set(&_kcopyd_must_die, 0);
-+
-+ add_wait_queue(&_job_queue, &wq);
-+
-+ down(&_run_lock);
-+ up(&start_lock);
-+
-+ while (1) {
-+ set_current_state(TASK_INTERRUPTIBLE);
-+
-+ if (atomic_read(&_kcopyd_must_die))
-+ break;
-+
-+ do_work();
-+ schedule();
-+ }
-+
-+ set_current_state(TASK_RUNNING);
-+ remove_wait_queue(&_job_queue, &wq);
-+
-+ up(&_run_lock);
-+
-+ return 0;
-+}
-+
-+static int start_daemon(void)
-+{
-+ static pid_t pid = 0;
-+
-+ down(&start_lock);
-+
-+ pid = kernel_thread(kcopyd, NULL, 0);
-+ if (pid <= 0) {
-+ DMERR("Failed to start kcopyd thread");
-+ return -EAGAIN;
-+ }
-+
-+ /*
-+ * wait for the daemon to up this mutex.
-+ */
-+ down(&start_lock);
-+ up(&start_lock);
-+
-+ return 0;
-+}
-+
-+static int stop_daemon(void)
-+{
-+ atomic_set(&_kcopyd_must_die, 1);
-+ wake_kcopyd();
-+ down(&_run_lock);
-+ up(&_run_lock);
-+
-+ return 0;
-+}
-+
-+static void wake_kcopyd(void)
-+{
-+ wake_up_interruptible(&_job_queue);
-+}
-+
-+static int calc_shift(unsigned int n)
-+{
-+ int s;
-+
-+ for (s = 0; n; s++, n >>= 1)
-+ ;
-+
-+ return --s;
-+}
-+
-+static void calc_block_sizes(struct kcopyd_job *job)
-+{
-+ job->block_size = get_hardsect_size(job->disk.dev);
-+ job->block_shift = calc_shift(job->block_size / SECTOR_SIZE);
-+ job->bpp_shift = PAGE_SHIFT - job->block_shift - SECTOR_SHIFT;
-+ job->bpp_mask = (1 << job->bpp_shift) - 1;
-+ job->nr_blocks = job->disk.count >> job->block_shift;
-+ atomic_set(&job->nr_requested, 0);
-+ atomic_set(&job->nr_incomplete, job->nr_blocks);
-+}
-+
-+int kcopyd_io(struct kcopyd_job *job)
-+{
-+ calc_block_sizes(job);
-+ push(job->pages[0] ? &_io_jobs : &_pages_jobs, job);
-+ wake_kcopyd();
-+ return 0;
-+}
-+
-+/*-----------------------------------------------------------------
-+ * The copier is implemented on top of the simpler async io
-+ * daemon above.
-+ *---------------------------------------------------------------*/
-+struct copy_info {
-+ kcopyd_notify_fn notify;
-+ void *notify_context;
-+
-+ struct kcopyd_region to;
-+};
-+
-+#define MIN_INFOS 128
-+static kmem_cache_t *_copy_cache = NULL;
-+static mempool_t *_copy_pool = NULL;
-+
-+static int init_copier(void)
-+{
-+ _copy_cache = kmem_cache_create("kcopyd-info",
-+ sizeof(struct copy_info),
-+ __alignof__(struct copy_info),
-+ 0, NULL, NULL);
-+ if (!_copy_cache)
-+ return -ENOMEM;
-+
-+ _copy_pool = mempool_create(MIN_INFOS, mempool_alloc_slab,
-+ mempool_free_slab, _copy_cache);
-+ if (!_copy_pool) {
-+ kmem_cache_destroy(_copy_cache);
-+ return -ENOMEM;
-+ }
-+
-+ return 0;
-+}
-+
-+static void exit_copier(void)
-+{
-+ if (_copy_pool)
-+ mempool_destroy(_copy_pool);
-+
-+ if (_copy_cache)
-+ kmem_cache_destroy(_copy_cache);
-+}
-+
-+static inline struct copy_info *alloc_copy_info(void)
-+{
-+ return mempool_alloc(_copy_pool, GFP_KERNEL);
-+}
-+
-+static inline void free_copy_info(struct copy_info *info)
-+{
-+ mempool_free(info, _copy_pool);
-+}
-+
-+void copy_complete(struct kcopyd_job *job)
-+{
-+ struct copy_info *info = (struct copy_info *) job->context;
-+
-+ if (info->notify)
-+ info->notify(job->err, info->notify_context);
-+
-+ free_copy_info(info);
-+ kcopyd_free_pages(job->nr_pages, job->pages);
-+ kcopyd_free_job(job);
-+}
-+
-+/*
-+ * These callback functions implement the state machine that copies regions.
-+ */
-+void copy_write(struct kcopyd_job *job)
-+{
-+ struct copy_info *info = (struct copy_info *) job->context;
-+
-+ if (job->err && info->notify) {
-+ info->notify(job->err, job->context);
-+ kcopyd_free_job(job);
-+ free_copy_info(info);
-+ return;
-+ }
-+
-+ job->rw = WRITE;
-+ memcpy(&job->disk, &info->to, sizeof(job->disk));
-+ job->callback = copy_complete;
-+ job->context = info;
-+
-+ /*
-+ * Queue the write.
-+ */
-+ kcopyd_io(job);
-+}
-+
-+int kcopyd_copy(struct kcopyd_region *from, struct kcopyd_region *to,
-+ kcopyd_notify_fn fn, void *context)
-+{
-+ struct copy_info *info;
-+ struct kcopyd_job *job;
-+
-+ /*
-+ * Allocate a new copy_info.
-+ */
-+ info = alloc_copy_info();
-+ if (!info)
-+ return -ENOMEM;
-+
-+ job = kcopyd_alloc_job();
-+ if (!job) {
-+ free_copy_info(info);
-+ return -ENOMEM;
-+ }
-+
-+ /*
-+ * set up for the read.
-+ */
-+ info->notify = fn;
-+ info->notify_context = context;
-+ memcpy(&info->to, to, sizeof(*to));
-+
-+ job->rw = READ;
-+ memcpy(&job->disk, from, sizeof(*from));
-+
-+ job->offset = 0;
-+ calc_block_sizes(job);
-+ job->callback = copy_write;
-+ job->context = info;
-+
-+ /*
-+ * Trigger job.
-+ */
-+ kcopyd_io(job);
-+ return 0;
-+}
-+
-+/*-----------------------------------------------------------------
-+ * Unit setup
-+ *---------------------------------------------------------------*/
-+static struct {
-+ int (*init) (void);
-+ void (*exit) (void);
-+
-+} _inits[] = {
-+#define xx(n) { init_ ## n, exit_ ## n}
-+ xx(pages),
-+ xx(buffers),
-+ xx(jobs),
-+ xx(copier)
-+#undef xx
-+};
-+
-+static int _client_count = 0;
-+static DECLARE_MUTEX(_client_count_sem);
-+
-+static int kcopyd_init(void)
-+{
-+ const int count = sizeof(_inits) / sizeof(*_inits);
-+
-+ int r, i;
-+
-+ for (i = 0; i < count; i++) {
-+ r = _inits[i].init();
-+ if (r)
-+ goto bad;
-+ }
-+
-+ start_daemon();
-+ return 0;
-+
-+ bad:
-+ while (i--)
-+ _inits[i].exit();
-+
-+ return r;
-+}
-+
-+static void kcopyd_exit(void)
-+{
-+ int i = sizeof(_inits) / sizeof(*_inits);
-+
-+ if (stop_daemon())
-+ DMWARN("Couldn't stop kcopyd.");
-+
-+ while (i--)
-+ _inits[i].exit();
-+}
-+
-+void kcopyd_inc_client_count(void)
-+{
-+ /*
-+ * What I need here is an atomic_test_and_inc that returns
-+ * the previous value of the atomic... In its absence I lock
-+ * an int with a semaphore. :-(
-+ */
-+ down(&_client_count_sem);
-+ if (_client_count == 0)
-+ kcopyd_init();
-+ _client_count++;
-+
-+ up(&_client_count_sem);
-+}
-+
-+void kcopyd_dec_client_count(void)
-+{
-+ down(&_client_count_sem);
-+ if (--_client_count == 0)
-+ kcopyd_exit();
-+
-+ up(&_client_count_sem);
-+}
-diff -ruN linux-2.4.19-pre8/drivers/md/kcopyd.h linux/drivers/md/kcopyd.h
---- linux-2.4.19-pre8/drivers/md/kcopyd.h Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/kcopyd.h Mon May 20 14:17:36 2002
-@@ -0,0 +1,97 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software
-+ *
-+ * This file is released under the GPL.
-+ */
-+
-+#ifndef DM_KCOPYD_H
-+#define DM_KCOPYD_H
-+
-+/*
-+ * Needed for the definition of offset_t.
-+ */
-+#include <linux/device-mapper.h>
-+#include <linux/iobuf.h>
-+
-+struct kcopyd_region {
-+ kdev_t dev;
-+ offset_t sector;
-+ offset_t count;
-+};
-+
-+#define MAX_KCOPYD_PAGES 128
-+
-+struct kcopyd_job {
-+ struct list_head list;
-+
-+ /*
-+ * Error state of the job.
-+ */
-+ int err;
-+
-+ /*
-+ * Either READ or WRITE
-+ */
-+ int rw;
-+
-+ /*
-+ * The source or destination for the transfer.
-+ */
-+ struct kcopyd_region disk;
-+
-+ int nr_pages;
-+ struct page *pages[MAX_KCOPYD_PAGES];
-+
-+ /*
-+ * Shifts and masks that will be useful when dispatching
-+ * each buffer_head.
-+ */
-+ offset_t offset;
-+ offset_t block_size;
-+ offset_t block_shift;
-+ offset_t bpp_shift; /* blocks per page */
-+ offset_t bpp_mask;
-+
-+ /*
-+ * nr_blocks is how many buffer heads will have to be
-+ * displatched to service this job, nr_requested is how
-+ * many have been dispatched and nr_complete is how many
-+ * have come back.
-+ */
-+ unsigned int nr_blocks;
-+ atomic_t nr_requested;
-+ atomic_t nr_incomplete;
-+
-+ /*
-+ * Set this to ensure you are notified when the job has
-+ * completed. 'context' is for callback to use.
-+ */
-+ void (*callback)(struct kcopyd_job *job);
-+ void *context;
-+};
-+
-+/*
-+ * Low level async io routines.
-+ */
-+struct kcopyd_job *kcopyd_alloc_job(void);
-+void kcopyd_free_job(struct kcopyd_job *job);
-+
-+int kcopyd_queue_job(struct kcopyd_job *job);
-+
-+/*
-+ * Submit a copy job to kcopyd. This is built on top of the
-+ * previous three fns.
-+ */
-+typedef void (*kcopyd_notify_fn)(int err, void *context);
-+
-+int kcopyd_copy(struct kcopyd_region *from, struct kcopyd_region *to,
-+ kcopyd_notify_fn fn, void *context);
-+
-+/*
-+ * We only want kcopyd to reserve resources if someone is
-+ * actually using it.
-+ */
-+void kcopyd_inc_client_count(void);
-+void kcopyd_dec_client_count(void);
-+
-+#endif
-diff -ruN linux-2.4.19-pre8/include/linux/device-mapper.h linux/include/linux/device-mapper.h
---- linux-2.4.19-pre8/include/linux/device-mapper.h Thu Jan 1 01:00:00 1970
-+++ linux/include/linux/device-mapper.h Mon May 20 15:00:56 2002
-@@ -0,0 +1,64 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the LGPL.
-+ */
-+
-+#ifndef _LINUX_DEVICE_MAPPER_H
-+#define _LINUX_DEVICE_MAPPER_H
-+
-+#define DM_DIR "device-mapper" /* Slashes not supported */
-+#define DM_MAX_TYPE_NAME 16
-+#define DM_NAME_LEN 128
-+#define DM_UUID_LEN 129
-+
-+#ifdef __KERNEL__
-+
-+struct dm_table;
-+struct dm_dev;
-+typedef unsigned long offset_t;
-+
-+typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t;
-+
-+/*
-+ * Prototypes for functions for a target
-+ */
-+typedef int (*dm_ctr_fn) (struct dm_table *t, offset_t b, offset_t l,
-+ int argc, char **argv, void **context);
-+typedef void (*dm_dtr_fn) (struct dm_table *t, void *c);
-+typedef int (*dm_map_fn) (struct buffer_head *bh, int rw, void *context);
-+typedef int (*dm_err_fn) (struct buffer_head *bh, int rw, void *context);
-+typedef int (*dm_status_fn) (status_type_t status_type, char *result,
-+ int maxlen, void *context);
-+typedef int (*dm_wait_fn) (void *context, wait_queue_t *wq, int add);
-+
-+void dm_error(const char *message);
-+
-+/*
-+ * Constructors should call these functions to ensure destination devices
-+ * are opened/closed correctly
-+ */
-+int dm_table_get_device(struct dm_table *t, const char *path,
-+ offset_t start, offset_t len, struct dm_dev **result);
-+void dm_table_put_device(struct dm_table *table, struct dm_dev *d);
-+
-+/*
-+ * Information about a target type
-+ */
-+struct target_type {
-+ const char *name;
-+ struct module *module;
-+ dm_ctr_fn ctr;
-+ dm_dtr_fn dtr;
-+ dm_map_fn map;
-+ dm_err_fn err;
-+ dm_status_fn status;
-+ dm_wait_fn wait;
-+};
-+
-+int dm_register_target(struct target_type *t);
-+int dm_unregister_target(struct target_type *t);
-+
-+#endif /* __KERNEL__ */
-+
-+#endif /* _LINUX_DEVICE_MAPPER_H */
-diff -ruN linux-2.4.19-pre8/include/linux/dm-ioctl.h linux/include/linux/dm-ioctl.h
---- linux-2.4.19-pre8/include/linux/dm-ioctl.h Thu Jan 1 01:00:00 1970
-+++ linux/include/linux/dm-ioctl.h Mon May 20 16:47:30 2002
-@@ -0,0 +1,113 @@
-+/*
-+ * Copyright (C) 2001 Sistina Software (UK) Limited.
-+ *
-+ * This file is released under the LGPL.
-+ */
-+
-+#ifndef _LINUX_DM_IOCTL_H
-+#define _LINUX_DM_IOCTL_H
-+
-+#include "device-mapper.h"
-+
-+/*
-+ * Implements a traditional ioctl interface to the device mapper.
-+ */
-+
-+/*
-+ * All ioctl arguments consist of a single chunk of memory, with
-+ * this structure at the start. If a uuid is specified any
-+ * lookup (eg. for a DM_INFO) will be done on that, *not* the
-+ * name.
-+ */
-+struct dm_ioctl {
-+ char version[16];
-+
-+ unsigned long data_size; /* total size of data passed in
-+ * including this struct */
-+
-+ unsigned long data_start; /* offset to start of data
-+ * relative to start of this struct */
-+
-+ char name[DM_NAME_LEN]; /* device name */
-+
-+ unsigned int target_count; /* in/out */
-+ unsigned int open_count; /* out */
-+ unsigned int flags; /* in/out */
-+
-+ __kernel_dev_t dev; /* in/out */
-+
-+ char uuid[DM_UUID_LEN]; /* unique identifier for
-+ * the block device */
-+};
-+
-+/*
-+ * Used to specify tables. These structures appear after the
-+ * dm_ioctl.
-+ */
-+struct dm_target_spec {
-+ int32_t status; /* used when reading from kernel only */
-+ unsigned long long sector_start;
-+ unsigned long long length;
-+
-+ char target_type[DM_MAX_TYPE_NAME];
-+
-+ unsigned long next; /* offset in bytes to next target_spec */
-+
-+ /*
-+ * Parameter string starts immediately after this object.
-+ * Be careful to add padding after string to ensure correct
-+ * alignment of subsequent dm_target_spec.
-+ */
-+};
-+
-+/*
-+ * Used to retrieve the target dependencies.
-+ */
-+struct dm_target_deps {
-+ unsigned int count;
-+
-+ __kernel_dev_t dev[0]; /* out */
-+};
-+
-+#define DM_IOCTL 0xfd
-+
-+enum {
-+ DM_CREATE_CMD = 0,
-+ DM_REMOVE_CMD,
-+ DM_SUSPEND_CMD,
-+ DM_RELOAD_CMD,
-+ DM_INFO_CMD,
-+ DM_RENAME_CMD,
-+ DM_VERSION_CMD,
-+ DM_DEPS_CMD,
-+ DM_REMOVE_ALL_CMD,
-+ DM_GET_STATUS_CMD,
-+ DM_WAIT_EVENT_CMD
-+};
-+
-+#define DM_CREATE _IOWR(DM_IOCTL, DM_CREATE_CMD, struct dm_ioctl)
-+#define DM_REMOVE _IOW(DM_IOCTL, DM_REMOVE_CMD, struct dm_ioctl)
-+#define DM_SUSPEND _IOW(DM_IOCTL, DM_SUSPEND_CMD, struct dm_ioctl)
-+#define DM_RELOAD _IOW(DM_IOCTL, DM_RELOAD_CMD, struct dm_ioctl)
-+#define DM_INFO _IOWR(DM_IOCTL, DM_INFO_CMD, struct dm_ioctl)
-+#define DM_RENAME _IOW(DM_IOCTL, DM_RENAME_CMD, struct dm_ioctl)
-+#define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
-+#define DM_DEPS _IOWR(DM_IOCTL, DM_DEPS_CMD, struct dm_ioctl)
-+#define DM_REMOVE_ALL _IOR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
-+#define DM_GET_STATUS _IOWR(DM_IOCTL, DM_GET_STATUS_CMD, struct dm_ioctl)
-+#define DM_WAIT_EVENT _IOR(DM_IOCTL, DM_WAIT_EVENT_CMD, struct dm_ioctl)
-+
-+#define DM_IOCTL_VERSION "0.94"
-+#define DM_DRIVER_VERSION "0.94.11-ioctl (2002-05-20)"
-+
-+/* Status bits */
-+#define DM_READONLY_FLAG 0x00000001
-+#define DM_SUSPEND_FLAG 0x00000002
-+#define DM_EXISTS_FLAG 0x00000004
-+#define DM_PERSISTENT_DEV_FLAG 0x00000008
-+
-+/* Flag passed into ioctl STATUS command to get table information
-+ rather than current status */
-+#define DM_STATUS_TABLE_FLAG 0x00000010
-+
-+#endif /* _LINUX_DM_IOCTL_H */
-diff -ruN linux-2.4.19-pre8/include/linux/fs.h linux/include/linux/fs.h
---- linux-2.4.19-pre8/include/linux/fs.h Mon May 20 16:37:59 2002
-+++ linux/include/linux/fs.h Mon May 20 17:03:43 2002
-@@ -258,7 +258,10 @@
- char * b_data; /* pointer to data block */
- struct page *b_page; /* the page this bh is mapped to */
- void (*b_end_io)(struct buffer_head *bh, int uptodate); /* I/O completion */
-- void *b_private; /* reserved for b_end_io */
-+ void *b_private; /* reserved for b_end_io, also used by ext3 */
-+ void *b_bdev_private; /* a hack to get around ext3 using b_private
-+ * after handing the buffer_head to the
-+ * block layer */
-
- unsigned long b_rsector; /* Real buffer location on disk */
- wait_queue_head_t b_wait;
-diff -ruN linux-2.4.19-pre8/include/linux/mempool.h linux/include/linux/mempool.h
---- linux-2.4.19-pre8/include/linux/mempool.h Thu Jan 1 01:00:00 1970
-+++ linux/include/linux/mempool.h Mon May 20 16:58:40 2002
-@@ -0,0 +1,41 @@
-+/*
-+ * memory buffer pool support
-+ */
-+#ifndef _LINUX_MEMPOOL_H
-+#define _LINUX_MEMPOOL_H
-+
-+#include <linux/list.h>
-+#include <linux/wait.h>
-+
-+struct mempool_s;
-+typedef struct mempool_s mempool_t;
-+
-+typedef void * (mempool_alloc_t)(int gfp_mask, void *pool_data);
-+typedef void (mempool_free_t)(void *element, void *pool_data);
-+
-+struct mempool_s {
-+ spinlock_t lock;
-+ int min_nr, curr_nr;
-+ struct list_head elements;
-+
-+ void *pool_data;
-+ mempool_alloc_t *alloc;
-+ mempool_free_t *free;
-+ wait_queue_head_t wait;
-+};
-+extern mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
-+ mempool_free_t *free_fn, void *pool_data);
-+extern void mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask);
-+extern void mempool_destroy(mempool_t *pool);
-+extern void * mempool_alloc(mempool_t *pool, int gfp_mask);
-+extern void mempool_free(void *element, mempool_t *pool);
-+
-+
-+/*
-+ * A mempool_alloc_t and mempool_free_t that get the memory from
-+ * a slab that is passed in through pool_data.
-+ */
-+void *mempool_alloc_slab(int gfp_mask, void *pool_data);
-+void mempool_free_slab(void *element, void *pool_data);
-+
-+#endif /* _LINUX_MEMPOOL_H */
-diff -ruN linux-2.4.19-pre8/mm/Makefile linux/mm/Makefile
---- linux-2.4.19-pre8/mm/Makefile Mon May 20 16:38:02 2002
-+++ linux/mm/Makefile Mon May 20 17:00:27 2002
-@@ -9,12 +9,12 @@
-
- O_TARGET := mm.o
-
--export-objs := shmem.o filemap.o memory.o page_alloc.o
-+export-objs := shmem.o filemap.o memory.o page_alloc.o mempool.o
-
- obj-y := memory.o mmap.o filemap.o mprotect.o mlock.o mremap.o \
- vmalloc.o slab.o bootmem.o swap.o vmscan.o page_io.o \
- page_alloc.o swap_state.o swapfile.o numa.o oom_kill.o \
-- shmem.o
-+ shmem.o mempool.o
-
- obj-$(CONFIG_HIGHMEM) += highmem.o
-
-diff -ruN linux-2.4.19-pre8/mm/mempool.c linux/mm/mempool.c
---- linux-2.4.19-pre8/mm/mempool.c Thu Jan 1 01:00:00 1970
-+++ linux/mm/mempool.c Mon May 20 16:58:40 2002
-@@ -0,0 +1,295 @@
-+/*
-+ * linux/mm/mempool.c
-+ *
-+ * memory buffer pool support. Such pools are mostly used
-+ * for guaranteed, deadlock-free memory allocations during
-+ * extreme VM load.
-+ *
-+ * started by Ingo Molnar, Copyright (C) 2001
-+ */
-+
-+#include <linux/mm.h>
-+#include <linux/slab.h>
-+#include <linux/module.h>
-+#include <linux/mempool.h>
-+#include <linux/compiler.h>
-+
-+/**
-+ * mempool_create - create a memory pool
-+ * @min_nr: the minimum number of elements guaranteed to be
-+ * allocated for this pool.
-+ * @alloc_fn: user-defined element-allocation function.
-+ * @free_fn: user-defined element-freeing function.
-+ * @pool_data: optional private data available to the user-defined functions.
-+ *
-+ * this function creates and allocates a guaranteed size, preallocated
-+ * memory pool. The pool can be used from the mempool_alloc and mempool_free
-+ * functions. This function might sleep. Both the alloc_fn() and the free_fn()
-+ * functions might sleep - as long as the mempool_alloc function is not called
-+ * from IRQ contexts. The element allocated by alloc_fn() must be able to
-+ * hold a struct list_head. (8 bytes on x86.)
-+ */
-+mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn,
-+ mempool_free_t *free_fn, void *pool_data)
-+{
-+ mempool_t *pool;
-+ int i;
-+
-+ pool = kmalloc(sizeof(*pool), GFP_KERNEL);
-+ if (!pool)
-+ return NULL;
-+ memset(pool, 0, sizeof(*pool));
-+
-+ spin_lock_init(&pool->lock);
-+ pool->min_nr = min_nr;
-+ pool->pool_data = pool_data;
-+ INIT_LIST_HEAD(&pool->elements);
-+ init_waitqueue_head(&pool->wait);
-+ pool->alloc = alloc_fn;
-+ pool->free = free_fn;
-+
-+ /*
-+ * First pre-allocate the guaranteed number of buffers.
-+ */
-+ for (i = 0; i < min_nr; i++) {
-+ void *element;
-+ struct list_head *tmp;
-+ element = pool->alloc(GFP_KERNEL, pool->pool_data);
-+
-+ if (unlikely(!element)) {
-+ /*
-+ * Not enough memory - free the allocated ones
-+ * and return:
-+ */
-+ list_for_each(tmp, &pool->elements) {
-+ element = tmp;
-+ pool->free(element, pool->pool_data);
-+ }
-+ kfree(pool);
-+
-+ return NULL;
-+ }
-+ tmp = element;
-+ list_add(tmp, &pool->elements);
-+ pool->curr_nr++;
-+ }
-+ return pool;
-+}
-+
-+/**
-+ * mempool_resize - resize an existing memory pool
-+ * @pool: pointer to the memory pool which was allocated via
-+ * mempool_create().
-+ * @new_min_nr: the new minimum number of elements guaranteed to be
-+ * allocated for this pool.
-+ * @gfp_mask: the usual allocation bitmask.
-+ *
-+ * This function shrinks/grows the pool. In the case of growing,
-+ * it cannot be guaranteed that the pool will be grown to the new
-+ * size immediately, but new mempool_free() calls will refill it.
-+ *
-+ * Note, the caller must guarantee that no mempool_destroy is called
-+ * while this function is running. mempool_alloc() & mempool_free()
-+ * might be called (eg. from IRQ contexts) while this function executes.
-+ */
-+void mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask)
-+{
-+ int delta;
-+ void *element;
-+ unsigned long flags;
-+ struct list_head *tmp;
-+
-+ if (new_min_nr <= 0)
-+ BUG();
-+
-+ spin_lock_irqsave(&pool->lock, flags);
-+ if (new_min_nr < pool->min_nr) {
-+ pool->min_nr = new_min_nr;
-+ /*
-+ * Free possible excess elements.
-+ */
-+ while (pool->curr_nr > pool->min_nr) {
-+ tmp = pool->elements.next;
-+ if (tmp == &pool->elements)
-+ BUG();
-+ list_del(tmp);
-+ element = tmp;
-+ pool->curr_nr--;
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+
-+ pool->free(element, pool->pool_data);
-+
-+ spin_lock_irqsave(&pool->lock, flags);
-+ }
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+ return;
-+ }
-+ delta = new_min_nr - pool->min_nr;
-+ pool->min_nr = new_min_nr;
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+
-+ /*
-+ * We refill the pool up to the new treshold - but we dont
-+ * (cannot) guarantee that the refill succeeds.
-+ */
-+ while (delta) {
-+ element = pool->alloc(gfp_mask, pool->pool_data);
-+ if (!element)
-+ break;
-+ mempool_free(element, pool);
-+ delta--;
-+ }
-+}
-+
-+/**
-+ * mempool_destroy - deallocate a memory pool
-+ * @pool: pointer to the memory pool which was allocated via
-+ * mempool_create().
-+ *
-+ * this function only sleeps if the free_fn() function sleeps. The caller
-+ * has to guarantee that no mempool_alloc() nor mempool_free() happens in
-+ * this pool when calling this function.
-+ */
-+void mempool_destroy(mempool_t *pool)
-+{
-+ void *element;
-+ struct list_head *head, *tmp;
-+
-+ if (!pool)
-+ return;
-+
-+ head = &pool->elements;
-+ for (tmp = head->next; tmp != head; ) {
-+ element = tmp;
-+ tmp = tmp->next;
-+ pool->free(element, pool->pool_data);
-+ pool->curr_nr--;
-+ }
-+ if (pool->curr_nr)
-+ BUG();
-+ kfree(pool);
-+}
-+
-+/**
-+ * mempool_alloc - allocate an element from a specific memory pool
-+ * @pool: pointer to the memory pool which was allocated via
-+ * mempool_create().
-+ * @gfp_mask: the usual allocation bitmask.
-+ *
-+ * this function only sleeps if the alloc_fn function sleeps or
-+ * returns NULL. Note that due to preallocation, this function
-+ * *never* fails when called from process contexts. (it might
-+ * fail if called from an IRQ context.)
-+ */
-+void * mempool_alloc(mempool_t *pool, int gfp_mask)
-+{
-+ void *element;
-+ unsigned long flags;
-+ struct list_head *tmp;
-+ int curr_nr;
-+ DECLARE_WAITQUEUE(wait, current);
-+ int gfp_nowait = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
-+
-+repeat_alloc:
-+ element = pool->alloc(gfp_nowait, pool->pool_data);
-+ if (likely(element != NULL))
-+ return element;
-+
-+ /*
-+ * If the pool is less than 50% full then try harder
-+ * to allocate an element:
-+ */
-+ if ((gfp_mask != gfp_nowait) && (pool->curr_nr <= pool->min_nr/2)) {
-+ element = pool->alloc(gfp_mask, pool->pool_data);
-+ if (likely(element != NULL))
-+ return element;
-+ }
-+
-+ /*
-+ * Kick the VM at this point.
-+ */
-+ wakeup_bdflush();
-+
-+ spin_lock_irqsave(&pool->lock, flags);
-+ if (likely(pool->curr_nr)) {
-+ tmp = pool->elements.next;
-+ list_del(tmp);
-+ element = tmp;
-+ pool->curr_nr--;
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+ return element;
-+ }
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+
-+ /* We must not sleep in the GFP_ATOMIC case */
-+ if (gfp_mask == gfp_nowait)
-+ return NULL;
-+
-+ run_task_queue(&tq_disk);
-+
-+ add_wait_queue_exclusive(&pool->wait, &wait);
-+ set_task_state(current, TASK_UNINTERRUPTIBLE);
-+
-+ spin_lock_irqsave(&pool->lock, flags);
-+ curr_nr = pool->curr_nr;
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+
-+ if (!curr_nr)
-+ schedule();
-+
-+ current->state = TASK_RUNNING;
-+ remove_wait_queue(&pool->wait, &wait);
-+
-+ goto repeat_alloc;
-+}
-+
-+/**
-+ * mempool_free - return an element to the pool.
-+ * @element: pool element pointer.
-+ * @pool: pointer to the memory pool which was allocated via
-+ * mempool_create().
-+ *
-+ * this function only sleeps if the free_fn() function sleeps.
-+ */
-+void mempool_free(void *element, mempool_t *pool)
-+{
-+ unsigned long flags;
-+
-+ if (pool->curr_nr < pool->min_nr) {
-+ spin_lock_irqsave(&pool->lock, flags);
-+ if (pool->curr_nr < pool->min_nr) {
-+ list_add(element, &pool->elements);
-+ pool->curr_nr++;
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+ wake_up(&pool->wait);
-+ return;
-+ }
-+ spin_unlock_irqrestore(&pool->lock, flags);
-+ }
-+ pool->free(element, pool->pool_data);
-+}
-+
-+/*
-+ * A commonly used alloc and free fn.
-+ */
-+void *mempool_alloc_slab(int gfp_mask, void *pool_data)
-+{
-+ kmem_cache_t *mem = (kmem_cache_t *) pool_data;
-+ return kmem_cache_alloc(mem, gfp_mask);
-+}
-+
-+void mempool_free_slab(void *element, void *pool_data)
-+{
-+ kmem_cache_t *mem = (kmem_cache_t *) pool_data;
-+ kmem_cache_free(mem, element);
-+}
-+
-+
-+EXPORT_SYMBOL(mempool_create);
-+EXPORT_SYMBOL(mempool_resize);
-+EXPORT_SYMBOL(mempool_destroy);
-+EXPORT_SYMBOL(mempool_alloc);
-+EXPORT_SYMBOL(mempool_free);
-+EXPORT_SYMBOL(mempool_alloc_slab);
-+EXPORT_SYMBOL(mempool_free_slab);
-+
-diff -ruN linux-2.4.19-pre10/drivers/md/Config.in linux/drivers/md/Config.in
---- linux-2.4.19-pre10/drivers/md/Config.in Wed Jun 12 12:03:42 2002
-+++ linux/drivers/md/Config.in Thu Jun 13 17:12:16 2002
-@@ -14,5 +14,6 @@
+diff -ruN linux-2.4.19-rc1/Documentation/Configure.help linux/Documentation/Configure.help
+--- linux-2.4.19-rc1/Documentation/Configure.help Tue Jun 25 14:14:05 2002
++++ linux/Documentation/Configure.help Tue Jun 25 21:33:16 2002
+@@ -1775,6 +1775,18 @@
+ want), say M here and read <file:Documentation/modules.txt>. The
+ module will be called lvm-mod.o.
+
++Device-mapper support
++CONFIG_BLK_DEV_DM
++ This option lets you create logical block devices dynamically by
++ joining together segments of existing block devices. This mechanism
++ is used by the new version of the logical volume manager under
++ development, LVM2.
++
++ If you want to compile this as a module, say M here and read
++ <file:Documentation/modules.txt>. The module will be called dm-mod.o.
++
++ If unsure, say N.
++
+ Multiple devices driver support (RAID and LVM)
+ CONFIG_MD
+ Support multiple physical spindles through a single logical device.
+diff -ruN linux-2.4.19-rc1/drivers/md/Config.in linux/drivers/md/Config.in
+--- linux-2.4.19-rc1/drivers/md/Config.in Tue Jun 25 14:14:54 2002
++++ linux/drivers/md/Config.in Tue Jun 25 21:33:15 2002
+@@ -14,5 +14,8 @@
dep_tristate ' Multipath I/O support' CONFIG_MD_MULTIPATH $CONFIG_BLK_DEV_MD
dep_tristate ' Logical volume manager (LVM) support' CONFIG_BLK_DEV_LVM $CONFIG_MD
-+dep_tristate ' Device mapper support' CONFIG_BLK_DEV_DM $CONFIG_MD
++if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
++ dep_tristate ' Device-mapper support (EXPERIMENTAL)' CONFIG_BLK_DEV_DM $CONFIG_MD
++fi
endmenu
-diff -ruN linux-2.4.19-pre10/drivers/md/Makefile linux/drivers/md/Makefile
---- linux-2.4.19-pre10/drivers/md/Makefile Wed Jun 12 12:03:42 2002
-+++ linux/drivers/md/Makefile Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/drivers/md/Makefile linux/drivers/md/Makefile
+--- linux-2.4.19-rc1/drivers/md/Makefile Tue Jun 25 14:14:54 2002
++++ linux/drivers/md/Makefile Tue Jun 25 21:33:16 2002
@@ -4,9 +4,12 @@
O_TARGET := mddev.o
+
+dm-mod.o: $(dm-mod-objs)
+ $(LD) -r -o $@ $(dm-mod-objs)
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-exception-store.c linux/drivers/md/dm-exception-store.c
---- linux-2.4.19-pre10/drivers/md/dm-exception-store.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-exception-store.c linux/drivers/md/dm-exception-store.c
+--- linux-2.4.19-rc1/drivers/md/dm-exception-store.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-exception-store.c Thu Jun 13 14:58:15 2002
@@ -0,0 +1,727 @@
+/*
+
+ return 0;
+}
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-ioctl.c linux/drivers/md/dm-ioctl.c
---- linux-2.4.19-pre10/drivers/md/dm-ioctl.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-ioctl.c Thu Jun 13 15:05:00 2002
-@@ -0,0 +1,749 @@
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-ioctl.c linux/drivers/md/dm-ioctl.c
+--- linux-2.4.19-rc1/drivers/md/dm-ioctl.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-ioctl.c Wed Jun 19 13:16:33 2002
+@@ -0,0 +1,807 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+#include <linux/init.h>
+#include <linux/wait.h>
+
-+static void free_params(struct dm_ioctl *param)
-+{
-+ vfree(param);
-+}
-+
-+static int version(struct dm_ioctl *user)
-+{
-+ return copy_to_user(user, DM_DRIVER_VERSION, sizeof(DM_DRIVER_VERSION));
-+}
-+
-+static int copy_params(struct dm_ioctl *user, struct dm_ioctl **param)
-+{
-+ struct dm_ioctl tmp, *dmi;
-+
-+ if (copy_from_user(&tmp, user, sizeof(tmp)))
-+ return -EFAULT;
-+
-+ if (strcmp(DM_IOCTL_VERSION, tmp.version)) {
-+ DMWARN("struct dm_ioctl version incompatible");
-+ return -EINVAL;
-+ }
-+
-+ if (tmp.data_size < sizeof(tmp))
-+ return -EINVAL;
-+
-+ dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
-+ if (!dmi)
-+ return -ENOMEM;
-+
-+ if (copy_from_user(dmi, user, tmp.data_size)) {
-+ vfree(dmi);
-+ return -EFAULT;
-+ }
++/*-----------------------------------------------------------------
++ * Implementation of the ioctl commands
++ *---------------------------------------------------------------*/
+
-+ *param = dmi;
-+ return 0;
-+}
++/*
++ * All the ioctl commands get dispatched to functions with this
++ * prototype.
++ */
++typedef int (*ioctl_fn)(struct dm_ioctl *param, struct dm_ioctl *user);
+
-+static int validate_params(uint cmd, struct dm_ioctl *param)
++/*
++ * This is really a debug only call.
++ */
++static int remove_all(struct dm_ioctl *param, struct dm_ioctl *user)
+{
-+ /* Unless creating, either name of uuid but not both */
-+ if (cmd != DM_CREATE_CMD) {
-+ if ((!*param->uuid && !*param->name) ||
-+ (*param->uuid && *param->name)) {
-+ DMWARN("one of name or uuid must be supplied");
-+ return -EINVAL;
-+ }
-+ }
-+
-+ /* Ensure strings are terminated */
-+ param->name[DM_NAME_LEN - 1] = '\0';
-+ param->uuid[DM_UUID_LEN - 1] = '\0';
-+
++ dm_destroy_all();
+ return 0;
+}
+
+ return -EINVAL;
+}
+
-+static int next_target(struct dm_target_spec *last, unsigned long next,
++static int next_target(struct dm_target_spec *last, uint32_t next,
+ void *begin, void *end,
+ struct dm_target_spec **spec, char **params)
+{
+
+ for (i = 0; i < args->target_count; i++) {
+
-+ r = first ? next_target((struct dm_target_spec *) args,
++ if (first)
++ r = next_target((struct dm_target_spec *) args,
+ args->data_start,
-+ begin, end, &spec, ¶ms) :
-+ next_target(spec, spec->next, begin, end, &spec, ¶ms);
++ begin, end, &spec, ¶ms);
++ else
++ r = next_target(spec, spec->next, begin, end,
++ &spec, ¶ms);
+
+ if (r)
+ PARSE_ERROR("unable to find target");
+ * userland.
+ */
+static int results_to_user(struct dm_ioctl *user, struct dm_ioctl *param,
-+ void *data, unsigned long len)
++ void *data, uint32_t len)
+{
+ int r;
+ void *ptr = NULL;
+
-+ strncpy(param->version, DM_IOCTL_VERSION, sizeof(param->version));
-+
+ if (data) {
+ ptr = align_ptr(user + 1, sizeof(unsigned long));
+ param->data_start = ptr - (void *) user;
+ }
+
-+ r = copy_to_user(user, param, sizeof(*param));
++ /*
++ * The version number has already been filled in, so we
++ * just copy later fields.
++ */
++ r = copy_to_user(&user->data_size, ¶m->data_size,
++ sizeof(*param) - sizeof(param->version));
+ if (r)
-+ return r;
++ return -EFAULT;
+
+ if (data) {
+ if (param->data_start + len > param->data_size)
+ return -ENOSPC;
-+ r = copy_to_user(ptr, data, len);
++
++ if (copy_to_user(ptr, data, len))
++ r = -EFAULT;
+ }
+
+ return r;
+}
+
+/*
++ * Copies device info back to user space, used by
++ * the create and info ioctls.
++ */
++static int info(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ struct mapped_device *md;
++
++ param->flags = 0;
++
++ md = dm_get_name_r(lookup_name(param), lookup_type(param));
++ if (!md)
++ /*
++ * Device not found - returns cleared exists flag.
++ */
++ goto out;
++
++ __info(md, param);
++ dm_put_r(md);
++
++ out:
++ return results_to_user(user, param, NULL, 0);
++}
++
++static int create(struct dm_ioctl *param, struct dm_ioctl *user)
++{
++ int r, ro;
++ struct dm_table *t;
++ int minor;
++
++ r = dm_table_create(&t);
++ if (r)
++ return r;
++
++ r = populate_table(t, param);
++ if (r) {
++ dm_table_destroy(t);
++ return r;
++ }
++
++ minor = (param->flags & DM_PERSISTENT_DEV_FLAG) ?
++ MINOR(to_kdev_t(param->dev)) : -1;
++
++ ro = (param->flags & DM_READONLY_FLAG) ? 1 : 0;
++
++ r = dm_create(param->name, param->uuid, minor, ro, t);
++ if (r) {
++ dm_table_destroy(t);
++ return r;
++ }
++
++ r = info(param, user);
++ return r;
++}
++
++
++
++/*
+ * Build up the status struct for each target
+ */
+static int __status(struct mapped_device *md, struct dm_ioctl *param,
+{
+ int i;
+ struct dm_target_spec *spec;
-+ unsigned long long sector = 0LL;
++ uint64_t sector = 0LL;
+ char *outptr;
+ status_type_t type;
+
+}
+
+/*
-+ * Copies device info back to user space, used by
-+ * the create and info ioctls.
-+ */
-+static int info(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ struct mapped_device *md;
-+
-+ param->flags = 0;
-+
-+ md = dm_get_name_r(lookup_name(param), lookup_type(param));
-+ if (!md)
-+ /*
-+ * Device not found - returns cleared exists flag.
-+ */
-+ goto out;
-+
-+ __info(md, param);
-+ dm_put_r(md);
-+
-+ out:
-+ return results_to_user(user, param, NULL, 0);
-+}
-+
-+/*
+ * Retrieves a list of devices used by a particular dm device.
+ */
+static int dep(struct dm_ioctl *param, struct dm_ioctl *user)
+ return r;
+}
+
-+static int create(struct dm_ioctl *param, struct dm_ioctl *user)
-+{
-+ int r, ro;
-+ struct dm_table *t;
-+ int minor;
-+
-+ r = dm_table_create(&t);
-+ if (r)
-+ return r;
-+
-+ r = populate_table(t, param);
-+ if (r) {
-+ dm_table_destroy(t);
-+ return r;
-+ }
-+
-+ minor = (param->flags & DM_PERSISTENT_DEV_FLAG) ?
-+ MINOR(to_kdev_t(param->dev)) : -1;
-+
-+ ro = (param->flags & DM_READONLY_FLAG) ? 1 : 0;
-+
-+ r = dm_create(param->name, param->uuid, minor, ro, t);
-+ if (r) {
-+ dm_table_destroy(t);
-+ return r;
-+ }
-+
-+ r = info(param, user);
-+ return r;
-+}
-+
-+static int remove(struct dm_ioctl *param)
++static int remove(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ struct mapped_device *md;
+ return r;
+}
+
-+static int suspend(struct dm_ioctl *param)
++static int suspend(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ int r;
+ struct mapped_device *md;
+ return r;
+}
+
-+static int rename(struct dm_ioctl *param)
++static int rename(struct dm_ioctl *param, struct dm_ioctl *user)
+{
+ char *newname = (char *) param + param->data_start;
+
+ return 0;
+}
+
++
++/*-----------------------------------------------------------------
++ * Implementation of open/close/ioctl on the special char
++ * device.
++ *---------------------------------------------------------------*/
+static int ctl_open(struct inode *inode, struct file *file)
+{
+ /* only root can open this */
+ return 0;
+}
+
-+static int ctl_ioctl(struct inode *inode, struct file *file,
-+ uint command, ulong u)
++static ioctl_fn lookup_ioctl(unsigned int cmd)
++{
++ static struct {
++ int cmd;
++ ioctl_fn fn;
++ } _ioctls[] = {
++ {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
++ {DM_REMOVE_ALL_CMD, remove_all},
++ {DM_DEV_CREATE_CMD, create},
++ {DM_DEV_REMOVE_CMD, remove},
++ {DM_DEV_RELOAD_CMD, reload},
++ {DM_DEV_RENAME_CMD, rename},
++ {DM_DEV_SUSPEND_CMD, suspend},
++ {DM_DEV_DEPS_CMD, dep},
++ {DM_DEV_STATUS_CMD, info},
++ {DM_TARGET_STATUS_CMD, get_status},
++ {DM_TARGET_WAIT_CMD, wait_device_event},
++ };
++ static int nelts = sizeof(_ioctls) / sizeof(*_ioctls);
++
++ return (cmd >= nelts) ? NULL : _ioctls[cmd].fn;
++}
++
++/*
++ * As well as checking the version compatibility this always
++ * copies the kernel interface version out.
++ */
++static int check_version(int cmd, struct dm_ioctl *user)
+{
++ uint32_t version[3];
+ int r = 0;
-+ struct dm_ioctl *param;
-+ struct dm_ioctl *user = (struct dm_ioctl *) u;
-+ uint cmd = _IOC_NR(command);
-+
-+ /* Process commands without params first - always return version */
-+ switch (cmd) {
-+ case DM_REMOVE_ALL_CMD:
-+ dm_destroy_all();
-+ case DM_VERSION_CMD:
-+ return version(user);
-+ default:
-+ break;
++
++ if (copy_from_user(version, user->version, sizeof(version)))
++ return -EFAULT;
++
++ if ((DM_VERSION_MAJOR != version[0]) ||
++ (DM_VERSION_MINOR < version[1])) {
++ DMWARN("ioctl interface mismatch: "
++ "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
++ DM_VERSION_MAJOR, DM_VERSION_MINOR,
++ DM_VERSION_PATCHLEVEL,
++ version[0], version[1], version[2], cmd);
++ r = -EINVAL;
+ }
+
-+ r = copy_params(user, ¶m);
-+ if (r)
-+ goto err;
++ /*
++ * Fill in the kernel version.
++ */
++ version[0] = DM_VERSION_MAJOR;
++ version[1] = DM_VERSION_MINOR;
++ version[2] = DM_VERSION_PATCHLEVEL;
++ if (copy_to_user(user->version, version, sizeof(version)))
++ return -EFAULT;
+
-+ r = validate_params(cmd, param);
-+ if (r) {
-+ free_params(param);
-+ goto err;
++ return r;
++}
++
++static void free_params(struct dm_ioctl *param)
++{
++ vfree(param);
++}
++
++static int copy_params(struct dm_ioctl *user, struct dm_ioctl **param)
++{
++ struct dm_ioctl tmp, *dmi;
++
++ if (copy_from_user(&tmp, user, sizeof(tmp)))
++ return -EFAULT;
++
++ if (tmp.data_size < sizeof(tmp))
++ return -EINVAL;
++
++ dmi = (struct dm_ioctl *) vmalloc(tmp.data_size);
++ if (!dmi)
++ return -ENOMEM;
++
++ if (copy_from_user(dmi, user, tmp.data_size)) {
++ vfree(dmi);
++ return -EFAULT;
+ }
+
-+ switch (cmd) {
-+ case DM_INFO_CMD:
-+ r = info(param, user);
-+ break;
++ *param = dmi;
++ return 0;
++}
+
-+ case DM_SUSPEND_CMD:
-+ r = suspend(param);
-+ break;
++static int validate_params(uint cmd, struct dm_ioctl *param)
++{
++ /* Unless creating, either name of uuid but not both */
++ if (cmd != DM_DEV_CREATE_CMD) {
++ if ((!*param->uuid && !*param->name) ||
++ (*param->uuid && *param->name)) {
++ DMWARN("one of name or uuid must be supplied");
++ return -EINVAL;
++ }
++ }
+
-+ case DM_CREATE_CMD:
-+ r = create(param, user);
-+ break;
++ /* Ensure strings are terminated */
++ param->name[DM_NAME_LEN - 1] = '\0';
++ param->uuid[DM_UUID_LEN - 1] = '\0';
+
-+ case DM_RELOAD_CMD:
-+ r = reload(param, user);
-+ break;
++ return 0;
++}
+
-+ case DM_REMOVE_CMD:
-+ r = remove(param);
-+ break;
++static int ctl_ioctl(struct inode *inode, struct file *file,
++ uint command, ulong u)
++{
+
-+ case DM_RENAME_CMD:
-+ r = rename(param);
-+ break;
++ int r = 0, cmd;
++ struct dm_ioctl *param;
++ struct dm_ioctl *user = (struct dm_ioctl *) u;
++ ioctl_fn fn = NULL;
+
-+ case DM_DEPS_CMD:
-+ r = dep(param, user);
-+ break;
++ if (_IOC_TYPE(command) != DM_IOCTL)
++ return -ENOTTY;
+
-+ case DM_GET_STATUS_CMD:
-+ r = get_status(param, user);
-+ break;
++ cmd = _IOC_NR(command);
+
-+ case DM_WAIT_EVENT_CMD:
-+ r = wait_device_event(param, user);
-+ break;
++ /*
++ * Check the interface version passed in. This also
++ * writes out the kernel's interface version.
++ */
++ r = check_version(cmd, user);
++ if (r)
++ return r;
+
-+ default:
++ /*
++ * Nothing more to do for the version command.
++ */
++ if (cmd == DM_VERSION_CMD)
++ return 0;
++
++ fn = lookup_ioctl(cmd);
++ if (!fn) {
+ DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
-+ r = -ENOTTY;
++ return -ENOTTY;
+ }
+
-+ free_params(param);
-+ return r;
++ /*
++ * Copy the parameters into kernel space.
++ */
++ r = copy_params(user, ¶m);
++ if (r)
++ return r;
+
-+ err:
-+ version(user);
++ r = validate_params(cmd, param);
++ if (r) {
++ free_params(param);
++ return r;
++ }
++
++ r = fn(param, user);
++ free_params(param);
+ return r;
+}
+
+static struct file_operations _ctl_fops = {
-+ open: ctl_open,
-+ release:ctl_close,
-+ ioctl: ctl_ioctl,
-+ owner: THIS_MODULE,
++ open: ctl_open,
++ release: ctl_close,
++ ioctl: ctl_ioctl,
++ owner: THIS_MODULE,
+};
+
+static devfs_handle_t _ctl_handle;
+
+static struct miscdevice _dm_misc = {
-+ minor: MISC_DYNAMIC_MINOR,
-+ name: DM_NAME,
-+ fops: &_ctl_fops
++ minor: MISC_DYNAMIC_MINOR,
++ name: DM_NAME,
++ fops: &_ctl_fops
+};
+
+/* Create misc character device and link to DM_DIR/control */
+ }
+ devfs_auto_unregister(_dm_misc.devfs_handle, _ctl_handle);
+
++ DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
++ DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
++ DM_DRIVER_EMAIL);
+ return 0;
+
+ failed:
+ if (misc_deregister(&_dm_misc) < 0)
+ DMERR("misc_deregister failed for control device");
+}
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-linear.c linux/drivers/md/dm-linear.c
---- linux-2.4.19-pre10/drivers/md/dm-linear.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-linear.c linux/drivers/md/dm-linear.c
+--- linux-2.4.19-rc1/drivers/md/dm-linear.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-linear.c Thu Jun 13 14:59:09 2002
@@ -0,0 +1,125 @@
+/*
+ if (r < 0)
+ DMERR("linear: unregister failed %d", r);
+}
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-mirror.c linux/drivers/md/dm-mirror.c
---- linux-2.4.19-pre10/drivers/md/dm-mirror.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm-mirror.c Thu Jun 13 17:03:27 2002
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-mirror.c linux/drivers/md/dm-mirror.c
+--- linux-2.4.19-rc1/drivers/md/dm-mirror.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm-mirror.c Wed Jun 19 13:28:45 2002
@@ -0,0 +1,343 @@
+/*
+ * Copyright (C) 2002 Sistina Software (UK) Limited.
+ }
+
+ if (err) {
-+ DMERR("Mirror block IO failed"); /* More detail to follow... */
++ DMERR("Mirror block IO failed"); /* More detail to follow... */
+ lc->error = 1;
+ return;
+ }
+ * c-file-style: "linux"
+ * End:
+ */
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-snapshot.c linux/drivers/md/dm-snapshot.c
---- linux-2.4.19-pre10/drivers/md/dm-snapshot.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-snapshot.c linux/drivers/md/dm-snapshot.c
+--- linux-2.4.19-rc1/drivers/md/dm-snapshot.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-snapshot.c Thu Jun 13 15:12:59 2002
@@ -0,0 +1,1182 @@
+/*
+ * c-file-style: "linux"
+ * End:
+ */
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-snapshot.h linux/drivers/md/dm-snapshot.h
---- linux-2.4.19-pre10/drivers/md/dm-snapshot.h Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-snapshot.h linux/drivers/md/dm-snapshot.h
+--- linux-2.4.19-rc1/drivers/md/dm-snapshot.h Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-snapshot.h Thu Jun 13 16:52:31 2002
@@ -0,0 +1,147 @@
+/*
+}
+
+#endif
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-stripe.c linux/drivers/md/dm-stripe.c
---- linux-2.4.19-pre10/drivers/md/dm-stripe.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-stripe.c linux/drivers/md/dm-stripe.c
+--- linux-2.4.19-rc1/drivers/md/dm-stripe.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-stripe.c Thu Jun 13 15:07:43 2002
@@ -0,0 +1,234 @@
+/*
+
+ return;
+}
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-table.c linux/drivers/md/dm-table.c
---- linux-2.4.19-pre10/drivers/md/dm-table.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-table.c linux/drivers/md/dm-table.c
+--- linux-2.4.19-rc1/drivers/md/dm-table.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-table.c Thu Jun 13 17:09:46 2002
@@ -0,0 +1,421 @@
+/*
+EXPORT_SYMBOL(dm_table_get_device);
+EXPORT_SYMBOL(dm_table_put_device);
+EXPORT_SYMBOL(dm_table_event);
-diff -ruN linux-2.4.19-pre10/drivers/md/dm-target.c linux/drivers/md/dm-target.c
---- linux-2.4.19-pre10/drivers/md/dm-target.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/dm-target.c linux/drivers/md/dm-target.c
+--- linux-2.4.19-rc1/drivers/md/dm-target.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/dm-target.c Thu Jun 13 15:07:55 2002
@@ -0,0 +1,242 @@
+/*
+
+EXPORT_SYMBOL(dm_register_target);
+EXPORT_SYMBOL(dm_unregister_target);
-diff -ruN linux-2.4.19-pre10/drivers/md/dm.c linux/drivers/md/dm.c
---- linux-2.4.19-pre10/drivers/md/dm.c Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm.c Thu Jun 13 16:28:55 2002
-@@ -0,0 +1,1169 @@
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.c linux/drivers/md/dm.c
+--- linux-2.4.19-rc1/drivers/md/dm.c Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm.c Tue Jun 18 18:29:48 2002
+@@ -0,0 +1,1174 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+#define DEFAULT_READ_AHEAD 64
+
+static const char *_name = DM_NAME;
-+static const char *_version = "0.94.12-ioctl (2002-06-13)";
-+static const char *_email = "lvm-devel@lists.sistina.com";
+
+static int major = 0;
+static int _major = 0;
+
+ _dev_dir = devfs_mk_dir(0, DM_DIR, NULL);
+
-+ DMINFO("%s initialised: %s", _version, _email);
+ return 0;
+}
+
+ hardsect_size[_major] = NULL;
+ _major = 0;
+
-+ DMINFO("%s cleaned up", _version);
++ DMINFO("cleaned up");
+}
+
+/*
+ if (size < result)
+ result = size;
+ }
++
++ /*
++ * I think it's safe to assume that no block devices have
++ * a hard sector size this large.
++ */
++ if (result == INT_MAX)
++ result = 512;
++
+ return result;
+}
+
+MODULE_DESCRIPTION(DM_NAME " driver");
+MODULE_AUTHOR("Joe Thornber <thornber@sistina.com>");
+MODULE_LICENSE("GPL");
-diff -ruN linux-2.4.19-pre10/drivers/md/dm.h linux/drivers/md/dm.h
---- linux-2.4.19-pre10/drivers/md/dm.h Thu Jan 1 01:00:00 1970
-+++ linux/drivers/md/dm.h Thu Jun 13 16:52:29 2002
-@@ -0,0 +1,232 @@
+diff -ruN linux-2.4.19-rc1/drivers/md/dm.h linux/drivers/md/dm.h
+--- linux-2.4.19-rc1/drivers/md/dm.h Thu Jan 1 01:00:00 1970
++++ linux/drivers/md/dm.h Tue Jun 18 20:05:34 2002
+@@ -0,0 +1,233 @@
+/*
+ * Internal header file for device mapper
+ *
+#include <linux/init.h>
+
+#define DM_NAME "device-mapper" /* Name for messaging */
++#define DM_DRIVER_EMAIL "lvm-devel@lists.sistina.com"
+#define MAX_DEPTH 16
+#define NODE_SIZE L1_CACHE_BYTES
+#define KEYS_PER_NODE (NODE_SIZE / sizeof(offset_t))
+void dm_stripe_exit(void);
+
+#endif
-diff -ruN linux-2.4.19-pre10/drivers/md/kcopyd.c linux/drivers/md/kcopyd.c
---- linux-2.4.19-pre10/drivers/md/kcopyd.c Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/kcopyd.c linux/drivers/md/kcopyd.c
+--- linux-2.4.19-rc1/drivers/md/kcopyd.c Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/kcopyd.c Thu Jun 13 15:18:21 2002
@@ -0,0 +1,832 @@
+/*
+
+ up(&_client_count_sem);
+}
-diff -ruN linux-2.4.19-pre10/drivers/md/kcopyd.h linux/drivers/md/kcopyd.h
---- linux-2.4.19-pre10/drivers/md/kcopyd.h Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/drivers/md/kcopyd.h linux/drivers/md/kcopyd.h
+--- linux-2.4.19-rc1/drivers/md/kcopyd.h Thu Jan 1 01:00:00 1970
+++ linux/drivers/md/kcopyd.h Thu Jun 13 16:52:29 2002
@@ -0,0 +1,101 @@
+/*
+void kcopyd_dec_client_count(void);
+
+#endif
-diff -ruN linux-2.4.19-pre10/include/linux/device-mapper.h linux/include/linux/device-mapper.h
---- linux-2.4.19-pre10/include/linux/device-mapper.h Thu Jan 1 01:00:00 1970
+diff -ruN linux-2.4.19-rc1/include/linux/device-mapper.h linux/include/linux/device-mapper.h
+--- linux-2.4.19-rc1/include/linux/device-mapper.h Thu Jan 1 01:00:00 1970
+++ linux/include/linux/device-mapper.h Thu Jun 13 15:01:29 2002
@@ -0,0 +1,62 @@
+/*
+#endif /* __KERNEL__ */
+
+#endif /* _LINUX_DEVICE_MAPPER_H */
-diff -ruN linux-2.4.19-pre10/include/linux/dm-ioctl.h linux/include/linux/dm-ioctl.h
---- linux-2.4.19-pre10/include/linux/dm-ioctl.h Thu Jan 1 01:00:00 1970
-+++ linux/include/linux/dm-ioctl.h Thu Jun 13 16:28:56 2002
-@@ -0,0 +1,113 @@
+diff -ruN linux-2.4.19-rc1/include/linux/dm-ioctl.h linux/include/linux/dm-ioctl.h
+--- linux-2.4.19-rc1/include/linux/dm-ioctl.h Thu Jan 1 01:00:00 1970
++++ linux/include/linux/dm-ioctl.h Tue Jun 25 17:40:32 2002
+@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2001 Sistina Software (UK) Limited.
+ *
+#define _LINUX_DM_IOCTL_H
+
+#include "device-mapper.h"
++#include "types.h"
+
+/*
+ * Implements a traditional ioctl interface to the device mapper.
+ * name.
+ */
+struct dm_ioctl {
-+ char version[16];
-+
-+ unsigned long data_size; /* total size of data passed in
-+ * including this struct */
-+
-+ unsigned long data_start; /* offset to start of data
-+ * relative to start of this struct */
++ /*
++ * The version number is made up of three parts:
++ * major - no backward or forward compatibility,
++ * minor - only backwards compatible,
++ * patch - both backwards and forwards compatible.
++ *
++ * All clients of the ioctl interface should fill in the
++ * version number of the interface that they were
++ * compiled with.
++ *
++ * All recognised ioctl commands (ie. those that don't
++ * return -ENOTTY) fill out this field, even if the
++ * command failed.
++ */
++ uint32_t version[3]; /* in/out */
++ uint32_t data_size; /* total size of data passed in
++ * including this struct */
+
-+ char name[DM_NAME_LEN]; /* device name */
++ uint32_t data_start; /* offset to start of data
++ * relative to start of this struct */
+
-+ unsigned int target_count; /* in/out */
-+ unsigned int open_count; /* out */
-+ unsigned int flags; /* in/out */
++ uint32_t target_count; /* in/out */
++ uint32_t open_count; /* out */
++ uint32_t flags; /* in/out */
+
+ __kernel_dev_t dev; /* in/out */
+
++ char name[DM_NAME_LEN]; /* device name */
+ char uuid[DM_UUID_LEN]; /* unique identifier for
+ * the block device */
+};
+ */
+struct dm_target_spec {
+ int32_t status; /* used when reading from kernel only */
-+ unsigned long long sector_start;
-+ unsigned long long length;
++ uint64_t sector_start;
++ uint32_t length;
+
-+ char target_type[DM_MAX_TYPE_NAME];
++ /*
++ * Offset in bytes (from the start of this struct) to
++ * next target_spec.
++ */
++ uint32_t next;
+
-+ unsigned long next; /* offset in bytes to next target_spec */
++ char target_type[DM_MAX_TYPE_NAME];
+
+ /*
+ * Parameter string starts immediately after this object.
+ * Used to retrieve the target dependencies.
+ */
+struct dm_target_deps {
-+ unsigned int count;
++ uint32_t count;
+
+ __kernel_dev_t dev[0]; /* out */
+};
+
-+#define DM_IOCTL 0xfd
-+
++/*
++ * If you change this make sure you make the corresponding change
++ * to dm-ioctl.c:lookup_ioctl()
++ */
+enum {
-+ DM_CREATE_CMD = 0,
-+ DM_REMOVE_CMD,
-+ DM_SUSPEND_CMD,
-+ DM_RELOAD_CMD,
-+ DM_INFO_CMD,
-+ DM_RENAME_CMD,
-+ DM_VERSION_CMD,
-+ DM_DEPS_CMD,
++ /* Top level cmds */
++ DM_VERSION_CMD = 0,
+ DM_REMOVE_ALL_CMD,
-+ DM_GET_STATUS_CMD,
-+ DM_WAIT_EVENT_CMD
++
++ /* device level cmds */
++ DM_DEV_CREATE_CMD,
++ DM_DEV_REMOVE_CMD,
++ DM_DEV_RELOAD_CMD,
++ DM_DEV_RENAME_CMD,
++ DM_DEV_SUSPEND_CMD,
++ DM_DEV_DEPS_CMD,
++ DM_DEV_STATUS_CMD,
++
++ /* target level cmds */
++ DM_TARGET_STATUS_CMD,
++ DM_TARGET_WAIT_CMD
+};
+
-+#define DM_CREATE _IOWR(DM_IOCTL, DM_CREATE_CMD, struct dm_ioctl)
-+#define DM_REMOVE _IOW(DM_IOCTL, DM_REMOVE_CMD, struct dm_ioctl)
-+#define DM_SUSPEND _IOW(DM_IOCTL, DM_SUSPEND_CMD, struct dm_ioctl)
-+#define DM_RELOAD _IOW(DM_IOCTL, DM_RELOAD_CMD, struct dm_ioctl)
-+#define DM_INFO _IOWR(DM_IOCTL, DM_INFO_CMD, struct dm_ioctl)
-+#define DM_RENAME _IOW(DM_IOCTL, DM_RENAME_CMD, struct dm_ioctl)
-+#define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
-+#define DM_DEPS _IOWR(DM_IOCTL, DM_DEPS_CMD, struct dm_ioctl)
-+#define DM_REMOVE_ALL _IOR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
-+#define DM_GET_STATUS _IOWR(DM_IOCTL, DM_GET_STATUS_CMD, struct dm_ioctl)
-+#define DM_WAIT_EVENT _IOR(DM_IOCTL, DM_WAIT_EVENT_CMD, struct dm_ioctl)
-+
-+#define DM_IOCTL_VERSION "0.94"
-+#define DM_DRIVER_VERSION "0.94.12-ioctl (2002-06-13)"
++#define DM_IOCTL 0xfd
++
++#define DM_VERSION _IOWR(DM_IOCTL, DM_VERSION_CMD, struct dm_ioctl)
++#define DM_REMOVE_ALL _IOWR(DM_IOCTL, DM_REMOVE_ALL_CMD, struct dm_ioctl)
++
++#define DM_DEV_CREATE _IOWR(DM_IOCTL, DM_DEV_CREATE_CMD, struct dm_ioctl)
++#define DM_DEV_REMOVE _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)
++#define DM_DEV_RELOAD _IOWR(DM_IOCTL, DM_DEV_RELOAD_CMD, struct dm_ioctl)
++#define DM_DEV_SUSPEND _IOWR(DM_IOCTL, DM_DEV_SUSPEND_CMD, struct dm_ioctl)
++#define DM_DEV_RENAME _IOWR(DM_IOCTL, DM_DEV_RENAME_CMD, struct dm_ioctl)
++#define DM_DEV_DEPS _IOWR(DM_IOCTL, DM_DEV_DEPS_CMD, struct dm_ioctl)
++#define DM_DEV_STATUS _IOWR(DM_IOCTL, DM_DEV_STATUS_CMD, struct dm_ioctl)
++
++#define DM_TARGET_STATUS _IOWR(DM_IOCTL, DM_TARGET_STATUS_CMD, struct dm_ioctl)
++#define DM_TARGET_WAIT _IOWR(DM_IOCTL, DM_TARGET_WAIT_CMD, struct dm_ioctl)
++
++#define DM_VERSION_MAJOR 1
++#define DM_VERSION_MINOR 0
++#define DM_VERSION_PATCHLEVEL 0
++#define DM_VERSION_EXTRA "-ioctl (2002-06-25)"
+
+/* Status bits */
+#define DM_READONLY_FLAG 0x00000001
+#define DM_EXISTS_FLAG 0x00000004
+#define DM_PERSISTENT_DEV_FLAG 0x00000008
+
-+/* Flag passed into ioctl STATUS command to get table information
-+ rather than current status */
++/*
++ * Flag passed into ioctl STATUS command to get table information
++ * rather than current status.
++ */
+#define DM_STATUS_TABLE_FLAG 0x00000010
+
+#endif /* _LINUX_DM_IOCTL_H */
-diff -ruN linux-2.4.19-pre10/include/linux/fs.h linux/include/linux/fs.h
---- linux-2.4.19-pre10/include/linux/fs.h Wed Jun 12 12:35:57 2002
-+++ linux/include/linux/fs.h Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/include/linux/fs.h linux/include/linux/fs.h
+--- linux-2.4.19-rc1/include/linux/fs.h Tue Jun 25 14:15:42 2002
++++ linux/include/linux/fs.h Tue Jun 25 21:33:16 2002
@@ -260,7 +260,10 @@
char * b_data; /* pointer to data block */
struct page *b_page; /* the page this bh is mapped to */
unsigned long b_rsector; /* Real buffer location on disk */
wait_queue_head_t b_wait;
-diff -ruN linux-2.4.19-pre10/include/linux/mempool.h linux/include/linux/mempool.h
---- linux-2.4.19-pre10/include/linux/mempool.h Thu Jan 1 01:00:00 1970
-+++ linux/include/linux/mempool.h Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/include/linux/mempool.h linux/include/linux/mempool.h
+--- linux-2.4.19-rc1/include/linux/mempool.h Thu Jan 1 01:00:00 1970
++++ linux/include/linux/mempool.h Tue Jun 25 21:33:16 2002
@@ -0,0 +1,41 @@
+/*
+ * memory buffer pool support
+void mempool_free_slab(void *element, void *pool_data);
+
+#endif /* _LINUX_MEMPOOL_H */
-diff -ruN linux-2.4.19-pre10/include/linux/vmalloc.h linux/include/linux/vmalloc.h
---- linux-2.4.19-pre10/include/linux/vmalloc.h Wed Jun 12 12:35:58 2002
-+++ linux/include/linux/vmalloc.h Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/include/linux/vmalloc.h linux/include/linux/vmalloc.h
+--- linux-2.4.19-rc1/include/linux/vmalloc.h Tue Jun 25 14:15:45 2002
++++ linux/include/linux/vmalloc.h Tue Jun 25 21:33:16 2002
@@ -25,6 +25,7 @@
extern void vmfree_area_pages(unsigned long address, unsigned long size);
extern int vmalloc_area_pages(unsigned long address, unsigned long size,
int gfp_mask, pgprot_t prot);
-+extern void *vcalloc(unsigned long nmemb, unsigned long size);
++extern void *vcalloc(unsigned long nmemb, unsigned long elem_size);
/*
* Allocate any pages
-diff -ruN linux-2.4.19-pre10/mm/Makefile linux/mm/Makefile
---- linux-2.4.19-pre10/mm/Makefile Wed Jun 12 12:04:44 2002
-+++ linux/mm/Makefile Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/mm/Makefile linux/mm/Makefile
+--- linux-2.4.19-rc1/mm/Makefile Tue Jun 25 14:15:47 2002
++++ linux/mm/Makefile Tue Jun 25 21:33:16 2002
@@ -9,12 +9,12 @@
O_TARGET := mm.o
obj-$(CONFIG_HIGHMEM) += highmem.o
-diff -ruN linux-2.4.19-pre10/mm/mempool.c linux/mm/mempool.c
---- linux-2.4.19-pre10/mm/mempool.c Thu Jan 1 01:00:00 1970
-+++ linux/mm/mempool.c Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/mm/mempool.c linux/mm/mempool.c
+--- linux-2.4.19-rc1/mm/mempool.c Thu Jan 1 01:00:00 1970
++++ linux/mm/mempool.c Tue Jun 25 21:33:16 2002
@@ -0,0 +1,295 @@
+/*
+ * linux/mm/mempool.c
+EXPORT_SYMBOL(mempool_alloc_slab);
+EXPORT_SYMBOL(mempool_free_slab);
+
-diff -ruN linux-2.4.19-pre10/mm/vmalloc.c linux/mm/vmalloc.c
---- linux-2.4.19-pre10/mm/vmalloc.c Wed Jun 12 12:04:44 2002
-+++ linux/mm/vmalloc.c Thu Jun 13 17:12:16 2002
+diff -ruN linux-2.4.19-rc1/mm/vmalloc.c linux/mm/vmalloc.c
+--- linux-2.4.19-rc1/mm/vmalloc.c Tue Jun 25 14:15:47 2002
++++ linux/mm/vmalloc.c Tue Jun 25 21:33:16 2002
@@ -321,3 +321,22 @@
read_unlock(&vmlist_lock);
return buf - buf_start;
}
+
-+void *vcalloc(unsigned long nmemb, unsigned long size)
++void *vcalloc(unsigned long nmemb, unsigned long elem_size)
+{
-+ unsigned long len;
-+ void *mem;
++ unsigned long size;
++ void *addr;
+
+ /*
+ * Check that we're not going to overflow.
+ */
-+ if (nmemb > (ULONG_MAX / size))
++ if (nmemb > (ULONG_MAX / elem_size))
+ return NULL;
+
-+ len = nmemb * size;
-+ mem = vmalloc(len);
-+ if (mem)
-+ memset(mem, 0, len);
++ size = nmemb * elem_size;
++ addr = vmalloc(size);
++ if (addr)
++ memset(addr, 0, size);
+
-+ return mem;
++ return addr;
+}
git://sourceware.org / dm.git / commitdiff