From: Alasdair Kergon <agk@redhat.com>
Date: Wed, 14 Aug 2002 13:24:27 +0000 (+0000)
Subject: Sync some fixes with bitkeeper repository.
X-Git-Tag: beta5~6
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=392561249a51d24ce8dedae1a3b22dd4f6feb6fa;p=dm.git

Sync some fixes with bitkeeper repository.
---

diff --git a/VERSION b/VERSION
index 79301ee..cabb3e4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.96.03-cvs (2002-06-27)
+0.96.04-cvs (2002-08-14)
diff --git a/kernel/common/device-mapper.h b/kernel/common/device-mapper.h
index 047cbda..c6651ef 100644
--- a/kernel/common/device-mapper.h
+++ b/kernel/common/device-mapper.h
@@ -38,7 +38,8 @@ void dm_error(const char *message);
  * 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);
+			offset_t start, offset_t len,
+			int mode, struct dm_dev **result);
 void dm_table_put_device(struct dm_table *table, struct dm_dev *d);
 
 /*
diff --git a/kernel/common/dm-linear.c b/kernel/common/dm-linear.c
index d6a91f7..f240bf7 100644
--- a/kernel/common/dm-linear.c
+++ b/kernel/common/dm-linear.c
@@ -46,7 +46,7 @@ static int linear_ctr(struct dm_table *t, offset_t b, offset_t l,
 		goto bad;
 	}
 
-	if (dm_table_get_device(t, argv[0], start, l, &lc->dev)) {
+	if (dm_table_get_device(t, argv[0], start, l, t->mode, &lc->dev)) {
 		*context = "dm-linear: Device lookup failed";
 		goto bad;
 	}
diff --git a/kernel/common/dm-mirror.c b/kernel/common/dm-mirror.c
index 64a5337..ee8ba75 100644
--- a/kernel/common/dm-mirror.c
+++ b/kernel/common/dm-mirror.c
@@ -66,8 +66,8 @@ static void mirror_bh(struct mirror_c *mc, struct buffer_head *bh)
 	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,
+			   ((long)bh->b_data -
+			    (long)page_address(bh->b_page)) / 512,
 			   mirror_callback, mc);
 }
 
@@ -77,6 +77,7 @@ 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);
 
@@ -112,7 +113,7 @@ static void copy_callback(int err, void *context)
 
 		src.dev = lc->fromdev->dev;
 		src.sector = lc->frompos + lc->got_to;
-		src.count = min((unsigned long) lc->chunksize, 
+		src.count = min((unsigned long)lc->chunksize,
 				lc->size - lc->got_to);
 
 		dest.dev = lc->todev->dev;
@@ -154,7 +155,7 @@ static int mirror_ctr(struct dm_table *t, offset_t b, offset_t l,
 		return -ENOMEM;
 	}
 
-	if (dm_table_get_device(t, argv[0], 0, l, &lc->fromdev)) {
+	if (dm_table_get_device(t, argv[0], 0, l, t->mode, &lc->fromdev)) {
 		*context = "dm-mirror: Device lookup failed";
 		goto bad;
 	}
@@ -166,7 +167,7 @@ static int mirror_ctr(struct dm_table *t, offset_t b, offset_t l,
 		goto bad;
 	}
 
-	if (dm_table_get_device(t, argv[2], 0, l, &lc->todev)) {
+	if (dm_table_get_device(t, argv[2], 0, l, t->mode, &lc->todev)) {
 		*context = "dm-mirror: Device lookup failed";
 		dm_table_put_device(t, lc->fromdev);
 		goto bad;
@@ -209,7 +210,7 @@ static int mirror_ctr(struct dm_table *t, offset_t b, offset_t l,
 	/* Tell kcopyd to do the biz */
 	src.dev = lc->fromdev->dev;
 	src.sector = offset1;
-	src.count = min((unsigned long) chunksize, lc->size);
+	src.count = min((unsigned long)chunksize, lc->size);
 
 	dest.dev = lc->todev->dev;
 	dest.sector = offset2;
diff --git a/kernel/common/dm-snapshot.c b/kernel/common/dm-snapshot.c
index 5361847..7ec19f5 100644
--- a/kernel/common/dm-snapshot.c
+++ b/kernel/common/dm-snapshot.c
@@ -379,6 +379,16 @@ static int init_hash_tables(struct dm_snapshot *s)
 	return 0;
 }
 
+/*
+ * Round a number up to the nearest 'size' boundary.  size must
+ * be a power of 2.
+ */
+static inline ulong round_up(ulong n, ulong size)
+{
+	size--;
+	return (n + size) & ~size;
+}
+
 /*
  * Construct a snapshot mapping: <origin_dev> <COW-dev> <p/n> <chunk-size>
  */
@@ -424,22 +434,25 @@ static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
 		goto bad;
 	}
 
-	r = dm_table_get_device(t, origin_path, 0, 0, &s->origin);
+	r = dm_table_get_device(t, origin_path, 0, 0, FMODE_READ, &s->origin);
 	if (r) {
 		*context = "Cannot get origin device";
 		goto bad_free;
 	}
 
-	r = dm_table_get_device(t, cow_path, 0, 0, &s->cow);
+	r = dm_table_get_device(t, cow_path, 0, 0,
+				FMODE_READ | FMODE_WRITE, &s->cow);
 	if (r) {
 		dm_table_put_device(t, s->origin);
 		*context = "Cannot get COW device";
 		goto bad_free;
 	}
 
-	/* Chunk size must be multiple of page size. If it's wrong, fix it */
-	if (chunk_size < (PAGE_SIZE / SECTOR_SIZE))
-		chunk_size = PAGE_SIZE / SECTOR_SIZE;
+	/*
+	 * Chunk size must be multiple of page size.  Silently
+	 * round up if it's not.
+	 */
+	chunk_size = round_up(chunk_size, PAGE_SIZE / SECTOR_SIZE);
 
 	/* Validate the chunk size against the device block size */
 	blocksize = get_hardsect_size(s->cow->dev);
@@ -996,7 +1009,7 @@ static int origin_ctr(struct dm_table *t, offset_t b, offset_t l,
 		return -EINVAL;
 	}
 
-	r = dm_table_get_device(t, argv[0], 0, l, &dev);
+	r = dm_table_get_device(t, argv[0], 0, l, t->mode, &dev);
 	if (r) {
 		*context = "Cannot get target device";
 		return r;
diff --git a/kernel/common/dm-stripe.c b/kernel/common/dm-stripe.c
index a05ee79..92a7bcf 100644
--- a/kernel/common/dm-stripe.c
+++ b/kernel/common/dm-stripe.c
@@ -56,7 +56,7 @@ static int get_stripe(struct dm_table *t, struct stripe_c *sc,
 		return -EINVAL;
 
 	if (dm_table_get_device(t, argv[0], start, sc->stripe_width,
-				&sc->stripe[stripe].dev))
+				t->mode, &sc->stripe[stripe].dev))
 		return -ENXIO;
 
 	sc->stripe[stripe].physical_start = start;
diff --git a/kernel/common/dm-table.c b/kernel/common/dm-table.c
index 786996f..1282680 100644
--- a/kernel/common/dm-table.c
+++ b/kernel/common/dm-table.c
@@ -104,7 +104,7 @@ static int alloc_targets(struct dm_table *t, int num)
 	return 0;
 }
 
-int dm_table_create(struct dm_table **result)
+int dm_table_create(struct dm_table **result, int mode)
 {
 	struct dm_table *t = kmalloc(sizeof(*t), GFP_NOIO);
 
@@ -122,6 +122,7 @@ int dm_table_create(struct dm_table **result)
 	}
 
 	init_waitqueue_head(&t->eventq);
+	t->mode = mode;
 	*result = t;
 	return 0;
 }
@@ -244,7 +245,7 @@ static int open_dev(struct dm_dev *d)
 	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)))
+	if ((err = blkdev_get(d->bd, d->mode, 0, BDEV_FILE)))
 		return err;
 
 	return 0;
@@ -283,12 +284,36 @@ static int check_device_area(kdev_t dev, offset_t start, offset_t len)
 	return ((start < dev_size) && (len <= (dev_size - start)));
 }
 
+/*
+ * This upgrades the mode on an already open dm_dev.  Being
+ * careful to leave things as they were if we fail to reopen the
+ * device.
+ */
+static int upgrade_mode(struct dm_dev *dd, int new_mode)
+{
+	int r;
+	struct dm_dev dd_copy;
+
+	memcpy(&dd_copy, dd, sizeof(dd_copy));
+
+	dd->mode |= new_mode;
+	dd->bd = NULL;
+	r = open_dev(dd);
+	if (!r)
+		close_dev(&dd_copy);
+	else
+		memcpy(dd, &dd_copy, sizeof(dd_copy));
+
+	return r;
+}
+
 /*
  * 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)
+			offset_t start, offset_t len, int mode,
+			struct dm_dev **result)
 {
 	int r;
 	kdev_t dev;
@@ -310,6 +335,7 @@ int dm_table_get_device(struct dm_table *t, const char *path,
 		if (!dd)
 			return -ENOMEM;
 
+		dd->mode = mode;
 		dd->dev = dev;
 		dd->bd = NULL;
 
@@ -320,6 +346,11 @@ int dm_table_get_device(struct dm_table *t, const char *path,
 
 		atomic_set(&dd->count, 0);
 		list_add(&dd->list, &t->devices);
+
+	} else if (dd->mode != (mode | dd->mode)) {
+		r = upgrade_mode(dd, mode);
+		if (r)
+			return r;
 	}
 	atomic_inc(&dd->count);
 
diff --git a/kernel/common/dm.c b/kernel/common/dm.c
index f58b896..6c2ff98 100644
--- a/kernel/common/dm.c
+++ b/kernel/common/dm.c
@@ -5,7 +5,6 @@
  */
 
 #include "dm.h"
-#include "kcopyd.h"
 
 #include <linux/blk.h>
 #include <linux/blkpg.h>
@@ -437,7 +436,7 @@ static inline int call_err_fn(struct io_hook *ih, struct buffer_head *bh)
  */
 static void dec_pending(struct buffer_head *bh, int uptodate)
 {
-	struct io_hook *ih = bh->b_bdev_private;
+	struct io_hook *ih = bh->b_private;
 
 	if (!uptodate && call_err_fn(ih, bh))
 		return;
@@ -447,7 +446,7 @@ static void dec_pending(struct buffer_head *bh, int uptodate)
 		wake_up(&ih->md->wait);
 
 	bh->b_end_io = ih->end_io;
-	bh->b_bdev_private = ih->context;
+	bh->b_private = ih->context;
 	free_io_hook(ih);
 
 	bh->b_end_io(bh, uptodate);
@@ -510,7 +509,7 @@ static inline int __map_buffer(struct mapped_device *md,
 	ih->rw = rw;
 	ih->target = ti;
 	ih->end_io = bh->b_end_io;
-	ih->context = bh->b_bdev_private;
+	ih->context = bh->b_private;
 
 	r = fn(bh, rw, context);
 
@@ -518,7 +517,7 @@ static inline int __map_buffer(struct mapped_device *md,
 		/* hook the end io request fn */
 		atomic_inc(&md->pending);
 		bh->b_end_io = dec_pending;
-		bh->b_bdev_private = ih;
+		bh->b_private = ih;
 
 	} else if (r == 0)
 		/* we don't need to hook */
diff --git a/kernel/common/dm.h b/kernel/common/dm.h
index 6ba0bb5..a9ca3f4 100644
--- a/kernel/common/dm.h
+++ b/kernel/common/dm.h
@@ -41,6 +41,8 @@ struct dm_dev {
 	atomic_t count;
 	struct list_head list;
 
+	int mode;
+
 	kdev_t dev;
 	struct block_device *bd;
 };
@@ -76,6 +78,13 @@ struct dm_table {
 	offset_t *highs;
 	struct target *targets;
 
+	/*
+	 * Indicates the rw permissions for the new logical
+	 * device.  This should be a combination of FMODE_READ
+	 * and FMODE_WRITE.
+	 */
+	int mode;
+
 	/* a list of devices used by this table */
 	struct list_head devices;
 
@@ -167,7 +176,7 @@ 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);
+int dm_table_create(struct dm_table **result, int mode);
 void dm_table_destroy(struct dm_table *t);
 
 int dm_table_add_target(struct dm_table *t, offset_t highs,
@@ -179,14 +188,6 @@ int dm_table_complete(struct dm_table *t);
  */
 void dm_table_event(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)
@@ -214,20 +215,27 @@ static inline int array_too_big(unsigned long fixed, unsigned long obj,
 }
 
 /*
- * The device-mapper can be driven through one of two interfaces;
- * ioctl or filesystem, depending which patch you have applied.
+ * Targets
  */
-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);
 
+int dm_snapshot_init(void);
+void dm_snapshot_exit(void);
+
+int dm_mirror_init(void);
+void dm_mirror_exit(void);
+
+/*
+ * Init functions for the user interface to device-mapper.  At
+ * the moment an ioctl interface on a special char device is
+ * used.  A filesystem based interface would be a nicer way to
+ * go.
+ */
+int __init dm_interface_init(void);
+void dm_interface_exit(void);
+
 #endif
diff --git a/kernel/common/kcopyd.c b/kernel/common/kcopyd.c
index b7d2af8..328ba5a 100644
--- a/kernel/common/kcopyd.c
+++ b/kernel/common/kcopyd.c
@@ -179,12 +179,21 @@ static struct buffer_head *alloc_buffer(void)
  */
 static void free_buffer(struct buffer_head *bh)
 {
-	int flags;
+	int flags, was_empty;
 
 	spin_lock_irqsave(&_buffer_lock, flags);
+	was_empty = (_free_buffers == NULL) ? 1 : 0;
 	bh->b_reqnext = _free_buffers;
 	_free_buffers = bh;
 	spin_unlock_irqrestore(&_buffer_lock, flags);
+
+	/*
+	 * If the buffer list was empty then kcopyd probably went
+	 * to sleep because it ran out of buffer heads, so let's
+	 * wake it up.
+	 */
+	if (was_empty)
+		wake_kcopyd();
 }
 
 /*-----------------------------------------------------------------
diff --git a/kernel/ioctl/dm-ioctl.c b/kernel/ioctl/dm-ioctl.c
index 258b75e..4109bf4 100644
--- a/kernel/ioctl/dm-ioctl.c
+++ b/kernel/ioctl/dm-ioctl.c
@@ -252,13 +252,23 @@ static int info(struct dm_ioctl *param, struct dm_ioctl *user)
 	return results_to_user(user, param, NULL, 0);
 }
 
+static inline int get_mode(struct dm_ioctl *param)
+{
+	int mode = FMODE_READ | FMODE_WRITE;
+
+	if (param->flags & DM_READONLY_FLAG)
+		mode = FMODE_READ;
+
+	return mode;
+}
+
 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);
+	r = dm_table_create(&t, get_mode(param));
 	if (r)
 		return r;
 
@@ -523,7 +533,7 @@ static int reload(struct dm_ioctl *param, struct dm_ioctl *user)
 	struct mapped_device *md;
 	struct dm_table *t;
 
-	r = dm_table_create(&t);
+	r = dm_table_create(&t, get_mode(param));
 	if (r)
 		return r;
 
diff --git a/kernel/ioctl/dm-ioctl.h b/kernel/ioctl/dm-ioctl.h
index 3b3f1dc..385df6a 100644
--- a/kernel/ioctl/dm-ioctl.h
+++ b/kernel/ioctl/dm-ioctl.h
@@ -127,8 +127,8 @@ enum {
 
 #define DM_VERSION_MAJOR	1
 #define DM_VERSION_MINOR	0
-#define DM_VERSION_PATCHLEVEL	2
-#define DM_VERSION_EXTRA	"-ioctl-cvs (2002-07-17)"
+#define DM_VERSION_PATCHLEVEL	3
+#define DM_VERSION_EXTRA	"-ioctl-cvs (2002-08-14)"
 
 /* Status bits */
 #define DM_READONLY_FLAG	0x00000001