From 78c28a729a85ef2518a0611f0da4c0a755a69dfb Mon Sep 17 00:00:00 2001 From: Alasdair Kergon Date: Wed, 26 Mar 2003 16:05:38 +0000 Subject: [PATCH] Patches for 2.4.20, first cut. --- patches/common/linux-2.4.20-arch64.patch | 191 + patches/common/linux-2.4.20-b_private.patch | 185 + patches/common/linux-2.4.20-config.patch | 53 + patches/common/linux-2.4.20-devmapper.patch | 6683 ++++++++++++++++ patches/common/linux-2.4.20-makefile.patch | 30 + patches/common/linux-2.4.20-mempool.patch | 356 + patches/common/linux-2.4.20-vcalloc.patch | 49 + patches/linux-2.4.20-VFS-lock.patch | 243 + patches/linux-2.4.20-devmapper-ioctl.patch | 7546 +++++++++++++++++++ 9 files changed, 15336 insertions(+) create mode 100644 patches/common/linux-2.4.20-arch64.patch create mode 100644 patches/common/linux-2.4.20-b_private.patch create mode 100644 patches/common/linux-2.4.20-config.patch create mode 100644 patches/common/linux-2.4.20-devmapper.patch create mode 100644 patches/common/linux-2.4.20-makefile.patch create mode 100644 patches/common/linux-2.4.20-mempool.patch create mode 100644 patches/common/linux-2.4.20-vcalloc.patch create mode 100644 patches/linux-2.4.20-VFS-lock.patch create mode 100644 patches/linux-2.4.20-devmapper-ioctl.patch diff --git a/patches/common/linux-2.4.20-arch64.patch b/patches/common/linux-2.4.20-arch64.patch new file mode 100644 index 0000000..5fe751a --- /dev/null +++ b/patches/common/linux-2.4.20-arch64.patch @@ -0,0 +1,191 @@ +diff -ruN linux-2.4.20/arch/mips64/kernel/ioctl32.c linux/arch/mips64/kernel/ioctl32.c +--- linux-2.4.20/arch/mips64/kernel/ioctl32.c Fri Jan 10 16:34:18 2003 ++++ linux/arch/mips64/kernel/ioctl32.c Wed Mar 26 13:37:24 2003 +@@ -33,6 +33,7 @@ + #include + #include + #include ++#include + + #include + #undef __KERNEL__ /* This file was born to be ugly ... */ +@@ -914,6 +915,20 @@ + IOCTL32_DEFAULT(STOP_ARRAY_RO), + IOCTL32_DEFAULT(RESTART_ARRAY_RW), + #endif /* CONFIG_MD */ ++ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++ IOCTL32_DEFAULT(DM_VERSION), ++ IOCTL32_DEFAULT(DM_REMOVE_ALL), ++ IOCTL32_DEFAULT(DM_DEV_CREATE), ++ IOCTL32_DEFAULT(DM_DEV_REMOVE), ++ IOCTL32_DEFAULT(DM_DEV_RELOAD), ++ IOCTL32_DEFAULT(DM_DEV_SUSPEND), ++ IOCTL32_DEFAULT(DM_DEV_RENAME), ++ IOCTL32_DEFAULT(DM_DEV_DEPS), ++ IOCTL32_DEFAULT(DM_DEV_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_WAIT), ++#endif /* CONFIG_BLK_DEV_DM */ + + IOCTL32_DEFAULT(MTIOCTOP), /* mtio.h ioctls */ + IOCTL32_HANDLER(MTIOCGET32, mt_ioctl_trans), +diff -ruN linux-2.4.20/arch/parisc/kernel/ioctl32.c linux/arch/parisc/kernel/ioctl32.c +--- linux-2.4.20/arch/parisc/kernel/ioctl32.c Fri Jan 10 16:34:19 2003 ++++ linux/arch/parisc/kernel/ioctl32.c Wed Mar 26 14:28:37 2003 +@@ -55,6 +55,7 @@ + #define max max */ + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -3415,6 +3416,20 @@ + COMPATIBLE_IOCTL(LV_BMAP) + COMPATIBLE_IOCTL(LV_SNAPSHOT_USE_RATE) + #endif /* LVM */ ++/* Device-Mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION) ++COMPATIBLE_IOCTL(DM_REMOVE_ALL) ++COMPATIBLE_IOCTL(DM_DEV_CREATE) ++COMPATIBLE_IOCTL(DM_DEV_REMOVE) ++COMPATIBLE_IOCTL(DM_DEV_RELOAD) ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND) ++COMPATIBLE_IOCTL(DM_DEV_RENAME) ++COMPATIBLE_IOCTL(DM_DEV_DEPS) ++COMPATIBLE_IOCTL(DM_DEV_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_WAIT) ++#endif /* CONFIG_BLK_DEV_DM */ + #if defined(CONFIG_DRM) || defined(CONFIG_DRM_MODULE) + COMPATIBLE_IOCTL(DRM_IOCTL_GET_MAGIC) + COMPATIBLE_IOCTL(DRM_IOCTL_IRQ_BUSID) +diff -ruN linux-2.4.20/arch/ppc64/kernel/ioctl32.c linux/arch/ppc64/kernel/ioctl32.c +--- linux-2.4.20/arch/ppc64/kernel/ioctl32.c Fri Jan 10 16:34:24 2003 ++++ linux/arch/ppc64/kernel/ioctl32.c Wed Mar 26 14:31:43 2003 +@@ -66,6 +66,7 @@ + #if defined(CONFIG_BLK_DEV_LVM) || defined(CONFIG_BLK_DEV_LVM_MODULE) + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -4362,6 +4363,20 @@ + COMPATIBLE_IOCTL(NBD_PRINT_DEBUG), + COMPATIBLE_IOCTL(NBD_SET_SIZE_BLOCKS), + COMPATIBLE_IOCTL(NBD_DISCONNECT), ++/* device-mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION), ++COMPATIBLE_IOCTL(DM_REMOVE_ALL), ++COMPATIBLE_IOCTL(DM_DEV_CREATE), ++COMPATIBLE_IOCTL(DM_DEV_REMOVE), ++COMPATIBLE_IOCTL(DM_DEV_RELOAD), ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND), ++COMPATIBLE_IOCTL(DM_DEV_RENAME), ++COMPATIBLE_IOCTL(DM_DEV_DEPS), ++COMPATIBLE_IOCTL(DM_DEV_STATUS), ++COMPATIBLE_IOCTL(DM_TARGET_STATUS), ++COMPATIBLE_IOCTL(DM_TARGET_WAIT), ++#endif /* CONFIG_BLK_DEV_DM */ + /* Remove *PRIVATE in 2.5 */ + COMPATIBLE_IOCTL(SIOCDEVPRIVATE), + COMPATIBLE_IOCTL(SIOCDEVPRIVATE+1), +diff -ruN linux-2.4.20/arch/s390x/kernel/ioctl32.c linux/arch/s390x/kernel/ioctl32.c +--- linux-2.4.20/arch/s390x/kernel/ioctl32.c Fri Jan 10 16:34:26 2003 ++++ linux/arch/s390x/kernel/ioctl32.c Wed Mar 26 13:36:43 2003 +@@ -25,6 +25,7 @@ + #include + #include + #include ++#include + #include + #include + #include +@@ -507,6 +508,18 @@ + IOCTL32_DEFAULT(VT_UNLOCKSWITCH), + + IOCTL32_DEFAULT(SIOCGSTAMP), ++ ++ IOCTL32_DEFAULT(DM_VERSION), ++ IOCTL32_DEFAULT(DM_REMOVE_ALL), ++ IOCTL32_DEFAULT(DM_DEV_CREATE), ++ IOCTL32_DEFAULT(DM_DEV_REMOVE), ++ IOCTL32_DEFAULT(DM_DEV_RELOAD), ++ IOCTL32_DEFAULT(DM_DEV_SUSPEND), ++ IOCTL32_DEFAULT(DM_DEV_RENAME), ++ IOCTL32_DEFAULT(DM_DEV_DEPS), ++ IOCTL32_DEFAULT(DM_DEV_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_WAIT), + + IOCTL32_HANDLER(SIOCGIFNAME, dev_ifname32), + IOCTL32_HANDLER(SIOCGIFCONF, dev_ifconf), +diff -ruN linux-2.4.20/arch/sparc64/kernel/ioctl32.c linux/arch/sparc64/kernel/ioctl32.c +--- linux-2.4.20/arch/sparc64/kernel/ioctl32.c Fri Jan 10 16:34:30 2003 ++++ linux/arch/sparc64/kernel/ioctl32.c Wed Mar 26 14:32:03 2003 +@@ -55,6 +55,7 @@ + #if defined(CONFIG_BLK_DEV_LVM) || defined(CONFIG_BLK_DEV_LVM_MODULE) + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -5023,6 +5024,21 @@ + COMPATIBLE_IOCTL(NBD_PRINT_DEBUG) + COMPATIBLE_IOCTL(NBD_SET_SIZE_BLOCKS) + COMPATIBLE_IOCTL(NBD_DISCONNECT) ++/* device-mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION) ++COMPATIBLE_IOCTL(DM_REMOVE_ALL) ++COMPATIBLE_IOCTL(DM_DEV_CREATE) ++COMPATIBLE_IOCTL(DM_DEV_REMOVE) ++COMPATIBLE_IOCTL(DM_DEV_RELOAD) ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND) ++COMPATIBLE_IOCTL(DM_DEV_RENAME) ++COMPATIBLE_IOCTL(DM_DEV_DEPS) ++COMPATIBLE_IOCTL(DM_DEV_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_WAIT) ++#endif /* CONFIG_BLK_DEV_DM */ ++ + /* And these ioctls need translation */ + HANDLE_IOCTL(MEMREADOOB32, mtd_rw_oob) + HANDLE_IOCTL(MEMWRITEOOB32, mtd_rw_oob) +diff -ruN linux-2.4.20/arch/x86_64/ia32/ia32_ioctl.c linux/arch/x86_64/ia32/ia32_ioctl.c +--- linux-2.4.20/arch/x86_64/ia32/ia32_ioctl.c Fri Jan 10 16:34:32 2003 ++++ linux/arch/x86_64/ia32/ia32_ioctl.c Wed Mar 26 14:29:31 2003 +@@ -62,6 +62,7 @@ + #define max max + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -3776,6 +3777,20 @@ + COMPATIBLE_IOCTL(LV_BMAP) + COMPATIBLE_IOCTL(LV_SNAPSHOT_USE_RATE) + #endif /* LVM */ ++/* Device-Mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION) ++COMPATIBLE_IOCTL(DM_REMOVE_ALL) ++COMPATIBLE_IOCTL(DM_DEV_CREATE) ++COMPATIBLE_IOCTL(DM_DEV_REMOVE) ++COMPATIBLE_IOCTL(DM_DEV_RELOAD) ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND) ++COMPATIBLE_IOCTL(DM_DEV_RENAME) ++COMPATIBLE_IOCTL(DM_DEV_DEPS) ++COMPATIBLE_IOCTL(DM_DEV_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_WAIT) ++#endif /* CONFIG_BLK_DEV_DM */ + #if defined(CONFIG_DRM) || defined(CONFIG_DRM_MODULE) + COMPATIBLE_IOCTL(DRM_IOCTL_GET_MAGIC) + COMPATIBLE_IOCTL(DRM_IOCTL_IRQ_BUSID) diff --git a/patches/common/linux-2.4.20-b_private.patch b/patches/common/linux-2.4.20-b_private.patch new file mode 100644 index 0000000..aad57ce --- /dev/null +++ b/patches/common/linux-2.4.20-b_private.patch @@ -0,0 +1,185 @@ +diff -ruN linux-2.4.20/fs/buffer.c linux/fs/buffer.c +--- linux-2.4.20/fs/buffer.c Fri Jan 10 16:35:24 2003 ++++ linux/fs/buffer.c Wed Mar 26 12:53:19 2003 +@@ -586,9 +586,10 @@ + void buffer_insert_inode_queue(struct buffer_head *bh, struct inode *inode) + { + spin_lock(&lru_list_lock); +- if (bh->b_inode) ++ if (buffer_inode(bh)) + list_del(&bh->b_inode_buffers); +- bh->b_inode = inode; ++ else ++ set_buffer_inode(bh); + list_add(&bh->b_inode_buffers, &inode->i_dirty_buffers); + spin_unlock(&lru_list_lock); + } +@@ -596,9 +597,10 @@ + void buffer_insert_inode_data_queue(struct buffer_head *bh, struct inode *inode) + { + spin_lock(&lru_list_lock); +- if (bh->b_inode) ++ if (buffer_inode(bh)) + list_del(&bh->b_inode_buffers); +- bh->b_inode = inode; ++ else ++ set_buffer_inode(bh); + list_add(&bh->b_inode_buffers, &inode->i_dirty_data_buffers); + spin_unlock(&lru_list_lock); + } +@@ -607,13 +609,13 @@ + remove_inode_queue functions. */ + static void __remove_inode_queue(struct buffer_head *bh) + { +- bh->b_inode = NULL; ++ clear_buffer_inode(bh); + list_del(&bh->b_inode_buffers); + } + + static inline void remove_inode_queue(struct buffer_head *bh) + { +- if (bh->b_inode) ++ if (buffer_inode(bh)) + __remove_inode_queue(bh); + } + +@@ -741,6 +743,7 @@ + bh->b_list = BUF_CLEAN; + bh->b_end_io = handler; + bh->b_private = private; ++ bh->b_journal_head = NULL; + } + + static void end_buffer_io_async(struct buffer_head * bh, int uptodate) +@@ -842,9 +845,9 @@ + bh = BH_ENTRY(list->next); + list_del(&bh->b_inode_buffers); + if (!buffer_dirty(bh) && !buffer_locked(bh)) +- bh->b_inode = NULL; ++ clear_buffer_inode(bh); + else { +- bh->b_inode = &tmp; ++ set_buffer_inode(bh); + list_add(&bh->b_inode_buffers, &tmp.i_dirty_buffers); + if (buffer_dirty(bh)) { + get_bh(bh); +@@ -1138,7 +1141,7 @@ + */ + static void __put_unused_buffer_head(struct buffer_head * bh) + { +- if (bh->b_inode) ++ if (buffer_inode(bh)) + BUG(); + if (nr_unused_buffer_heads >= MAX_UNUSED_BUFFERS) { + kmem_cache_free(bh_cachep, bh); +diff -ruN linux-2.4.20/fs/jbd/journal.c linux/fs/jbd/journal.c +--- linux-2.4.20/fs/jbd/journal.c Fri Jan 10 16:35:27 2003 ++++ linux/fs/jbd/journal.c Wed Mar 26 12:53:19 2003 +@@ -1664,8 +1664,8 @@ + * + * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit + * is set. This bit is tested in core kernel code where we need to take +- * JBD-specific actions. Testing the zeroness of ->b_private is not reliable +- * there. ++ * JBD-specific actions. Testing the zeroness of ->b_journal_head is not ++ * reliable there. + * + * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. + * +@@ -1720,9 +1720,9 @@ + + if (buffer_jbd(bh)) { + /* Someone did it for us! */ +- J_ASSERT_BH(bh, bh->b_private != NULL); ++ J_ASSERT_BH(bh, bh->b_journal_head != NULL); + journal_free_journal_head(jh); +- jh = bh->b_private; ++ jh = bh->b_journal_head; + } else { + /* + * We actually don't need jh_splice_lock when +@@ -1730,7 +1730,7 @@ + */ + spin_lock(&jh_splice_lock); + set_bit(BH_JBD, &bh->b_state); +- bh->b_private = jh; ++ bh->b_journal_head = jh; + jh->b_bh = bh; + atomic_inc(&bh->b_count); + spin_unlock(&jh_splice_lock); +@@ -1739,7 +1739,7 @@ + } + jh->b_jcount++; + spin_unlock(&journal_datalist_lock); +- return bh->b_private; ++ return bh->b_journal_head; + } + + /* +@@ -1772,7 +1772,7 @@ + J_ASSERT_BH(bh, jh2bh(jh) == bh); + BUFFER_TRACE(bh, "remove journal_head"); + spin_lock(&jh_splice_lock); +- bh->b_private = NULL; ++ bh->b_journal_head = NULL; + jh->b_bh = NULL; /* debug, really */ + clear_bit(BH_JBD, &bh->b_state); + __brelse(bh); +diff -ruN linux-2.4.20/include/linux/fs.h linux/include/linux/fs.h +--- linux-2.4.20/include/linux/fs.h Fri Jan 10 16:35:55 2003 ++++ linux/include/linux/fs.h Wed Mar 26 12:53:19 2003 +@@ -220,6 +220,7 @@ + BH_Wait_IO, /* 1 if we should write out this buffer */ + BH_Launder, /* 1 if we can throttle on this buffer */ + BH_JBD, /* 1 if it has an attached journal_head */ ++ BH_Inode, /* 1 if it is attached to i_dirty[_data]_buffers */ + + BH_PrivateStart,/* not a state bit, but the first bit available + * for private allocation by other entities +@@ -262,11 +263,10 @@ + 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_journal_head; /* ext3 journal_heads */ + unsigned long b_rsector; /* Real buffer location on disk */ + wait_queue_head_t b_wait; + +- struct inode * b_inode; + struct list_head b_inode_buffers; /* doubly linked list of inode dirty buffers */ + }; + +@@ -1184,6 +1184,21 @@ + set_bit(BH_Async, &bh->b_state); + else + clear_bit(BH_Async, &bh->b_state); ++} ++ ++static inline void set_buffer_inode(struct buffer_head *bh) ++{ ++ set_bit(BH_Inode, &bh->b_state); ++} ++ ++static inline void clear_buffer_inode(struct buffer_head *bh) ++{ ++ clear_bit(BH_Inode, &bh->b_state); ++} ++ ++static inline int buffer_inode(struct buffer_head *bh) ++{ ++ return test_bit(BH_Inode, &bh->b_state); + } + + /* +diff -ruN linux-2.4.20/include/linux/jbd.h linux/include/linux/jbd.h +--- linux-2.4.20/include/linux/jbd.h Fri Jan 10 16:35:55 2003 ++++ linux/include/linux/jbd.h Wed Mar 26 12:53:19 2003 +@@ -254,7 +254,7 @@ + + static inline struct journal_head *bh2jh(struct buffer_head *bh) + { +- return bh->b_private; ++ return bh->b_journal_head; + } + + #define HAVE_JOURNAL_CALLBACK_STATUS diff --git a/patches/common/linux-2.4.20-config.patch b/patches/common/linux-2.4.20-config.patch new file mode 100644 index 0000000..c9a8dda --- /dev/null +++ b/patches/common/linux-2.4.20-config.patch @@ -0,0 +1,53 @@ +diff -ruN linux-2.4.20/MAINTAINERS linux/MAINTAINERS +--- linux-2.4.20/MAINTAINERS Fri Jan 10 16:33:49 2003 ++++ linux/MAINTAINERS Wed Mar 26 12:53:19 2003 +@@ -439,6 +439,13 @@ + W: http://www.debian.org/~dz/i8k/ + S: Maintained + ++DEVICE MAPPER ++P: Joe Thornber ++M: dm@uk.sistina.com ++L: linux-LVM@sistina.com ++W: http://www.sistina.com/lvm ++S: Maintained ++ + DEVICE NUMBER REGISTRY + P: H. Peter Anvin + M: hpa@zytor.com +diff -ruN linux-2.4.20/drivers/md/Config.in linux/drivers/md/Config.in +--- linux-2.4.20/drivers/md/Config.in Fri Jan 10 16:34:50 2003 ++++ linux/drivers/md/Config.in Wed Mar 26 12:53:19 2003 +@@ -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 linux-2.4.20/Documentation/Configure.help linux/Documentation/Configure.help +--- linux-2.4.20/Documentation/Configure.help Fri Jan 10 16:33:55 2003 ++++ linux/Documentation/Configure.help Wed Mar 26 12:53:19 2003 +@@ -1822,6 +1822,20 @@ + want), say M here and read . The + module will be called lvm-mod.o. + ++Device-mapper support ++CONFIG_BLK_DEV_DM ++ Device-mapper is a low level volume manager. It works by allowing ++ people to specify mappings for ranges of logical sectors. Various ++ mapping types are available, in addition people may write their own ++ modules containing custom mappings if they wish. ++ ++ Higher level volume managers such as LVM2 use this driver. ++ ++ If you want to compile this as a module, say M here and read ++ . 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 --git a/patches/common/linux-2.4.20-devmapper.patch b/patches/common/linux-2.4.20-devmapper.patch new file mode 100644 index 0000000..18651ac --- /dev/null +++ b/patches/common/linux-2.4.20-devmapper.patch @@ -0,0 +1,6683 @@ +diff -ruN linux-2.4.20/drivers/md/dm-exception-store.c linux/drivers/md/dm-exception-store.c +--- linux-2.4.20/drivers/md/dm-exception-store.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-exception-store.c Wed Mar 26 14:21:16 2003 +@@ -0,0 +1,704 @@ ++/* ++ * 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 ++#include ++#include ++#include ++ ++/*----------------------------------------------------------------- ++ * 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; ++} ++ ++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; ++ ++ 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; ++ sector_t size = get_dev_size(store->snap->cow->dev); ++ ++ /* Is there enough room ? */ ++ if (size < ((ps->next_free + 1) * 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) == 1) ++ 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->valid) { ++ DMWARN("snapshot is marked invalid"); ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ 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 { ++ sector_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; ++ sector_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) ++{ ++ 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-2.4.20/drivers/md/dm-ioctl.c linux/drivers/md/dm-ioctl.c +--- linux-2.4.20/drivers/md/dm-ioctl.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-ioctl.c Wed Mar 26 14:34:50 2003 +@@ -0,0 +1,1160 @@ ++/* ++ * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include ++ ++#define DM_DRIVER_EMAIL "dm@uk.sistina.com" ++ ++/*----------------------------------------------------------------- ++ * The ioctl interface needs to be able to look up devices by ++ * name or uuid. ++ *---------------------------------------------------------------*/ ++struct hash_cell { ++ struct list_head name_list; ++ struct list_head uuid_list; ++ ++ char *name; ++ char *uuid; ++ struct mapped_device *md; ++ ++ /* I hate devfs */ ++ devfs_handle_t devfs_entry; ++}; ++ ++#define NUM_BUCKETS 64 ++#define MASK_BUCKETS (NUM_BUCKETS - 1) ++static struct list_head _name_buckets[NUM_BUCKETS]; ++static struct list_head _uuid_buckets[NUM_BUCKETS]; ++ ++static devfs_handle_t _dev_dir; ++void dm_hash_remove_all(void); ++ ++/* ++ * Guards access to all three tables. ++ */ ++static DECLARE_RWSEM(_hash_lock); ++ ++static void init_buckets(struct list_head *buckets) ++{ ++ unsigned int i; ++ ++ for (i = 0; i < NUM_BUCKETS; i++) ++ INIT_LIST_HEAD(buckets + i); ++} ++ ++int dm_hash_init(void) ++{ ++ init_buckets(_name_buckets); ++ init_buckets(_uuid_buckets); ++ _dev_dir = devfs_mk_dir(0, DM_DIR, NULL); ++ return 0; ++} ++ ++void dm_hash_exit(void) ++{ ++ dm_hash_remove_all(); ++ devfs_unregister(_dev_dir); ++} ++ ++/*----------------------------------------------------------------- ++ * Hash function: ++ * We're not really concerned with the str hash function being ++ * fast since it's only used by the ioctl interface. ++ *---------------------------------------------------------------*/ ++static unsigned int hash_str(const char *str) ++{ ++ const unsigned int hash_mult = 2654435387U; ++ unsigned int h = 0; ++ ++ while (*str) ++ h = (h + (unsigned int) *str++) * hash_mult; ++ ++ return h & MASK_BUCKETS; ++} ++ ++/*----------------------------------------------------------------- ++ * Code for looking up a device by name ++ *---------------------------------------------------------------*/ ++static struct hash_cell *__get_name_cell(const char *str) ++{ ++ struct list_head *tmp; ++ struct hash_cell *hc; ++ unsigned int h = hash_str(str); ++ ++ list_for_each(tmp, _name_buckets + h) { ++ hc = list_entry(tmp, struct hash_cell, name_list); ++ if (!strcmp(hc->name, str)) ++ return hc; ++ } ++ ++ return NULL; ++} ++ ++static struct hash_cell *__get_uuid_cell(const char *str) ++{ ++ struct list_head *tmp; ++ struct hash_cell *hc; ++ unsigned int h = hash_str(str); ++ ++ list_for_each(tmp, _uuid_buckets + h) { ++ hc = list_entry(tmp, struct hash_cell, uuid_list); ++ if (!strcmp(hc->uuid, str)) ++ return hc; ++ } ++ ++ return NULL; ++} ++ ++/*----------------------------------------------------------------- ++ * Inserting, removing and renaming a device. ++ *---------------------------------------------------------------*/ ++static inline char *kstrdup(const char *str) ++{ ++ char *r = kmalloc(strlen(str) + 1, GFP_KERNEL); ++ if (r) ++ strcpy(r, str); ++ return r; ++} ++ ++static struct hash_cell *alloc_cell(const char *name, const char *uuid, ++ struct mapped_device *md) ++{ ++ struct hash_cell *hc; ++ ++ hc = kmalloc(sizeof(*hc), GFP_KERNEL); ++ if (!hc) ++ return NULL; ++ ++ hc->name = kstrdup(name); ++ if (!hc->name) { ++ kfree(hc); ++ return NULL; ++ } ++ ++ if (!uuid) ++ hc->uuid = NULL; ++ ++ else { ++ hc->uuid = kstrdup(uuid); ++ if (!hc->uuid) { ++ kfree(hc->name); ++ kfree(hc); ++ return NULL; ++ } ++ } ++ ++ INIT_LIST_HEAD(&hc->name_list); ++ INIT_LIST_HEAD(&hc->uuid_list); ++ hc->md = md; ++ return hc; ++} ++ ++static void free_cell(struct hash_cell *hc) ++{ ++ if (hc) { ++ kfree(hc->name); ++ kfree(hc->uuid); ++ kfree(hc); ++ } ++} ++ ++/* ++ * devfs stuff. ++ */ ++static int register_with_devfs(struct hash_cell *hc) ++{ ++ kdev_t dev = dm_kdev(hc->md); ++ ++ hc->devfs_entry = ++ devfs_register(_dev_dir, hc->name, DEVFS_FL_CURRENT_OWNER, ++ major(dev), minor(dev), ++ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP, ++ &dm_blk_dops, NULL); ++ ++ return 0; ++} ++ ++static int unregister_with_devfs(struct hash_cell *hc) ++{ ++ devfs_unregister(hc->devfs_entry); ++ return 0; ++} ++ ++/* ++ * The kdev_t and uuid of a device can never change once it is ++ * initially inserted. ++ */ ++int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) ++{ ++ struct hash_cell *cell; ++ ++ /* ++ * Allocate the new cells. ++ */ ++ cell = alloc_cell(name, uuid, md); ++ if (!cell) ++ return -ENOMEM; ++ ++ /* ++ * Insert the cell into all three hash tables. ++ */ ++ down_write(&_hash_lock); ++ if (__get_name_cell(name)) ++ goto bad; ++ ++ list_add(&cell->name_list, _name_buckets + hash_str(name)); ++ ++ if (uuid) { ++ if (__get_uuid_cell(uuid)) { ++ list_del(&cell->name_list); ++ goto bad; ++ } ++ list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); ++ } ++ register_with_devfs(cell); ++ dm_get(md); ++ up_write(&_hash_lock); ++ ++ return 0; ++ ++ bad: ++ up_write(&_hash_lock); ++ free_cell(cell); ++ return -EBUSY; ++} ++ ++void __hash_remove(struct hash_cell *hc) ++{ ++ /* remove from the dev hash */ ++ list_del(&hc->uuid_list); ++ list_del(&hc->name_list); ++ unregister_with_devfs(hc); ++ dm_put(hc->md); ++} ++ ++void dm_hash_remove_all(void) ++{ ++ int i; ++ struct hash_cell *hc; ++ struct list_head *tmp, *n; ++ ++ down_write(&_hash_lock); ++ for (i = 0; i < NUM_BUCKETS; i++) { ++ list_for_each_safe(tmp, n, _name_buckets + i) { ++ hc = list_entry(tmp, struct hash_cell, name_list); ++ __hash_remove(hc); ++ } ++ } ++ up_write(&_hash_lock); ++} ++ ++int dm_hash_rename(const char *old, const char *new) ++{ ++ char *new_name, *old_name; ++ struct hash_cell *hc; ++ ++ /* ++ * duplicate new. ++ */ ++ new_name = kstrdup(new); ++ if (!new_name) ++ return -ENOMEM; ++ ++ down_write(&_hash_lock); ++ ++ /* ++ * Is new free ? ++ */ ++ hc = __get_name_cell(new); ++ if (hc) { ++ DMWARN("asked to rename to an already existing name %s -> %s", ++ old, new); ++ up_write(&_hash_lock); ++ return -EBUSY; ++ } ++ ++ /* ++ * Is there such a device as 'old' ? ++ */ ++ hc = __get_name_cell(old); ++ if (!hc) { ++ DMWARN("asked to rename a non existent device %s -> %s", ++ old, new); ++ up_write(&_hash_lock); ++ return -ENXIO; ++ } ++ ++ /* ++ * rename and move the name cell. ++ */ ++ list_del(&hc->name_list); ++ old_name = hc->name; ++ hc->name = new_name; ++ list_add(&hc->name_list, _name_buckets + hash_str(new_name)); ++ ++ /* rename the device node in devfs */ ++ unregister_with_devfs(hc); ++ register_with_devfs(hc); ++ ++ up_write(&_hash_lock); ++ kfree(old_name); ++ return 0; ++} ++ ++ ++/*----------------------------------------------------------------- ++ * 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); ++ ++/* ++ * 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); ++} ++ ++static int populate_table(struct dm_table *table, struct dm_ioctl *args) ++{ ++ int i = 0, r, first = 1; ++ struct dm_target_spec *spec; ++ char *params; ++ void *begin, *end; ++ ++ if (!args->target_count) { ++ DMWARN("populate_table: no targets specified"); ++ return -EINVAL; ++ } ++ ++ begin = (void *) args; ++ end = begin + args->data_size; ++ ++ 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) { ++ DMWARN("unable to find target"); ++ return -EINVAL; ++ } ++ ++ r = dm_table_add_target(table, spec->target_type, ++ spec->sector_start, spec->length, ++ params); ++ if (r) { ++ DMWARN("error adding target to table"); ++ return -EINVAL; ++ } ++ ++ first = 0; ++ } ++ ++ return dm_table_complete(table); ++} ++ ++/* ++ * 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 int __info(struct mapped_device *md, struct dm_ioctl *param) ++{ ++ kdev_t dev = dm_kdev(md); ++ struct dm_table *table; ++ struct block_device *bdev; ++ ++ param->flags = DM_EXISTS_FLAG; ++ if (dm_suspended(md)) ++ param->flags |= DM_SUSPEND_FLAG; ++ ++ param->dev = kdev_t_to_nr(dev); ++ bdev = bdget(param->dev); ++ if (!bdev) ++ return -ENXIO; ++ ++ param->open_count = bdev->bd_openers; ++ bdput(bdev); ++ ++ if (is_read_only(dev)) ++ param->flags |= DM_READONLY_FLAG; ++ ++ table = dm_get_table(md); ++ param->target_count = dm_table_get_num_targets(table); ++ dm_table_put(table); ++ ++ return 0; ++} ++ ++/* ++ * Always use UUID for lookups if it's present, otherwise use name. ++ */ ++static inline struct mapped_device *find_device(struct dm_ioctl *param) ++{ ++ struct hash_cell *hc; ++ struct mapped_device *md = NULL; ++ ++ down_read(&_hash_lock); ++ hc = *param->uuid ? __get_uuid_cell(param->uuid) : ++ __get_name_cell(param->name); ++ if (hc) { ++ md = hc->md; ++ ++ /* ++ * Sneakily write in both the name and the uuid ++ * while we have the cell. ++ */ ++ strncpy(param->name, hc->name, sizeof(param->name)); ++ if (hc->uuid) ++ strncpy(param->uuid, hc->uuid, sizeof(param->uuid) - 1); ++ else ++ param->uuid[0] = '\0'; ++ ++ dm_get(md); ++ } ++ up_read(&_hash_lock); ++ ++ return md; ++} ++ ++#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 = find_device(param); ++ if (!md) ++ /* ++ * Device not found - returns cleared exists flag. ++ */ ++ goto out; ++ ++ __info(md, param); ++ dm_put(md); ++ ++ out: ++ 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 check_name(const char *name) ++{ ++ if (strchr(name, '/')) { ++ DMWARN("invalid device name"); ++ return -EINVAL; ++ } ++ ++ return 0; ++} ++ ++static int create(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ kdev_t dev; ++ struct dm_table *t; ++ struct mapped_device *md; ++ int minor; ++ ++ r = check_name(param->name); ++ if (r) ++ return r; ++ ++ r = dm_table_create(&t, get_mode(param)); ++ if (r) ++ return r; ++ ++ r = populate_table(t, param); ++ if (r) { ++ dm_table_put(t); ++ return r; ++ } ++ ++ minor = (param->flags & DM_PERSISTENT_DEV_FLAG) ? ++ minor(to_kdev_t(param->dev)) : -1; ++ ++ r = dm_create(minor, t, &md); ++ if (r) { ++ dm_table_put(t); ++ return r; ++ } ++ dm_table_put(t); /* md will have grabbed its own reference */ ++ ++ dev = dm_kdev(md); ++ set_device_ro(dev, (param->flags & DM_READONLY_FLAG)); ++ r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); ++ dm_put(md); ++ ++ return r ? r : info(param, user); ++} ++ ++/* ++ * 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, num_targets; ++ struct dm_target_spec *spec; ++ char *outptr; ++ status_type_t type; ++ struct dm_table *table = dm_get_table(md); ++ ++ if (param->flags & DM_STATUS_TABLE_FLAG) ++ type = STATUSTYPE_TABLE; ++ else ++ type = STATUSTYPE_INFO; ++ ++ outptr = outbuf; ++ ++ /* Get all the target info */ ++ num_targets = dm_table_get_num_targets(table); ++ for (i = 0; i < num_targets; i++) { ++ struct dm_target *ti = dm_table_get_target(table, i); ++ ++ if (outptr - outbuf + ++ sizeof(struct dm_target_spec) > param->data_size) { ++ dm_table_put(table); ++ return -ENOMEM; ++ } ++ ++ spec = (struct dm_target_spec *) outptr; ++ ++ spec->status = 0; ++ spec->sector_start = ti->begin; ++ spec->length = ti->len; ++ strncpy(spec->target_type, ti->type->name, ++ sizeof(spec->target_type)); ++ ++ outptr += sizeof(struct dm_target_spec); ++ ++ /* Get the status/table string from the target driver */ ++ if (ti->type->status) ++ ti->type->status(ti, type, outptr, ++ outbuf + param->data_size - outptr); ++ else ++ outptr[0] = '\0'; ++ ++ outptr += strlen(outptr) + 1; ++ _align(outptr, ALIGNMENT); ++ spec->next = outptr - outbuf; ++ } ++ ++ param->target_count = num_targets; ++ *len = outptr - outbuf; ++ dm_table_put(table); ++ ++ 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 = find_device(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(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; ++ struct dm_table *table; ++ DECLARE_WAITQUEUE(wq, current); ++ ++ md = find_device(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); ++ table = dm_get_table(md); ++ dm_table_add_wait_queue(table, &wq); ++ dm_table_put(table); ++ dm_put(md); ++ ++ yield(); ++ 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; ++ struct dm_table *table; ++ ++ md = find_device(param); ++ if (!md) ++ goto out; ++ table = dm_get_table(md); ++ ++ /* ++ * Setup the basic dm_ioctl structure. ++ */ ++ __info(md, param); ++ ++ /* ++ * Count the devices. ++ */ ++ count = 0; ++ list_for_each(tmp, dm_table_get_devices(table)) ++ count++; ++ ++ /* ++ * Allocate a kernel space version of the dm_target_status ++ * struct. ++ */ ++ if (array_too_big(sizeof(*deps), sizeof(*deps->dev), count)) { ++ dm_table_put(table); ++ dm_put(md); ++ return -ENOMEM; ++ } ++ ++ len = sizeof(*deps) + (sizeof(*deps->dev) * count); ++ deps = kmalloc(len, GFP_KERNEL); ++ if (!deps) { ++ dm_table_put(table); ++ dm_put(md); ++ return -ENOMEM; ++ } ++ ++ /* ++ * Fill in the devices. ++ */ ++ deps->count = count; ++ count = 0; ++ list_for_each(tmp, dm_table_get_devices(table)) { ++ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); ++ deps->dev[count++] = dd->bdev->bd_dev; ++ } ++ dm_table_put(table); ++ dm_put(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) ++{ ++ struct hash_cell *hc; ++ ++ down_write(&_hash_lock); ++ hc = *param->uuid ? __get_uuid_cell(param->uuid) : ++ __get_name_cell(param->name); ++ if (!hc) { ++ DMWARN("device doesn't appear to be in the dev hash table."); ++ up_write(&_hash_lock); ++ return -EINVAL; ++ } ++ ++ /* ++ * You may ask the interface to drop its reference to an ++ * in use device. This is no different to unlinking a ++ * file that someone still has open. The device will not ++ * actually be destroyed until the last opener closes it. ++ * The name and uuid of the device (both are interface ++ * properties) will be available for reuse immediately. ++ * ++ * You don't want to drop a _suspended_ device from the ++ * interface, since that will leave you with no way of ++ * resuming it. ++ */ ++ if (dm_suspended(hc->md)) { ++ DMWARN("refusing to remove a suspended device."); ++ up_write(&_hash_lock); ++ return -EPERM; ++ } ++ ++ __hash_remove(hc); ++ up_write(&_hash_lock); ++ return 0; ++} ++ ++static int remove_all(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ dm_hash_remove_all(); ++ return 0; ++} ++ ++static int suspend(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ struct mapped_device *md; ++ ++ md = find_device(param); ++ if (!md) ++ return -ENXIO; ++ ++ if (param->flags & DM_SUSPEND_FLAG) ++ r = dm_suspend(md); ++ else ++ r = dm_resume(md); ++ ++ dm_put(md); ++ return r; ++} ++ ++static int reload(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ kdev_t dev; ++ struct mapped_device *md; ++ struct dm_table *t; ++ ++ r = dm_table_create(&t, get_mode(param)); ++ if (r) ++ return r; ++ ++ r = populate_table(t, param); ++ if (r) { ++ dm_table_put(t); ++ return r; ++ } ++ ++ md = find_device(param); ++ if (!md) { ++ dm_table_put(t); ++ return -ENXIO; ++ } ++ ++ r = dm_swap_table(md, t); ++ if (r) { ++ dm_put(md); ++ dm_table_put(t); ++ return r; ++ } ++ dm_table_put(t); /* md will have taken its own reference */ ++ ++ dev = dm_kdev(md); ++ set_device_ro(dev, (param->flags & DM_READONLY_FLAG)); ++ dm_put(md); ++ ++ r = info(param, user); ++ return r; ++} ++ ++static int rename(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ char *new_name = (char *) param + param->data_start; ++ ++ if (valid_str(new_name, (void *) param, ++ (void *) param + param->data_size)) { ++ DMWARN("Invalid new logical volume name supplied."); ++ return -EINVAL; ++ } ++ ++ r = check_name(new_name); ++ if (r) ++ return r; ++ ++ return dm_hash_rename(param->name, new_name); ++} ++ ++ ++/*----------------------------------------------------------------- ++ * Implementation of open/close/ioctl on the special char ++ * device. ++ *---------------------------------------------------------------*/ ++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}, ++ }; ++ ++ return (cmd >= ARRAY_SIZE(_ioctls)) ? 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) ++{ ++ /* Ignores parameters */ ++ if (cmd == DM_REMOVE_ALL_CMD) ++ return 0; ++ ++ /* 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; ++ ++ /* only root can play with this */ ++ if (!capable(CAP_SYS_ADMIN)) ++ return -EACCES; ++ ++ 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 = { ++ .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 = dm_hash_init(); ++ if (r) ++ return r; ++ ++ r = misc_register(&_dm_misc); ++ if (r) { ++ DMERR("misc_register failed for control device"); ++ dm_hash_exit(); ++ return r; ++ } ++ ++ r = devfs_generate_path(_dm_misc.devfs_handle, rname + 3, ++ sizeof rname - 3); ++ if (r == -ENOSYS) ++ goto done; /* 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); ++ ++ done: ++ 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); ++ dm_hash_exit(); ++ return r; ++} ++ ++void dm_interface_exit(void) ++{ ++ if (misc_deregister(&_dm_misc) < 0) ++ DMERR("misc_deregister failed for control device"); ++ ++ dm_hash_exit(); ++} +diff -ruN linux-2.4.20/drivers/md/dm-linear.c linux/drivers/md/dm-linear.c +--- linux-2.4.20/drivers/md/dm-linear.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-linear.c Wed Mar 26 13:27:22 2003 +@@ -0,0 +1,121 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++ ++/* ++ * Linear: maps a linear range of a device. ++ */ ++struct linear_c { ++ struct dm_dev *dev; ++ sector_t start; ++}; ++ ++/* ++ * Construct a linear mapping: ++ */ ++static int linear_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ struct linear_c *lc; ++ ++ if (argc != 2) { ++ ti->error = "dm-linear: Not enough arguments"; ++ return -EINVAL; ++ } ++ ++ lc = kmalloc(sizeof(*lc), GFP_KERNEL); ++ if (lc == NULL) { ++ ti->error = "dm-linear: Cannot allocate linear context"; ++ return -ENOMEM; ++ } ++ ++ if (sscanf(argv[1], SECTOR_FORMAT, &lc->start) != 1) { ++ ti->error = "dm-linear: Invalid device sector"; ++ goto bad; ++ } ++ ++ if (dm_get_device(ti, argv[0], lc->start, ti->len, ++ dm_table_get_mode(ti->table), &lc->dev)) { ++ ti->error = "dm-linear: Device lookup failed"; ++ goto bad; ++ } ++ ++ ti->private = lc; ++ return 0; ++ ++ bad: ++ kfree(lc); ++ return -EINVAL; ++} ++ ++static void linear_dtr(struct dm_target *ti) ++{ ++ struct linear_c *lc = (struct linear_c *) ti->private; ++ ++ dm_put_device(ti, lc->dev); ++ kfree(lc); ++} ++ ++static int linear_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ struct linear_c *lc = (struct linear_c *) ti->private; ++ ++ bh->b_rdev = lc->dev->dev; ++ bh->b_rsector = lc->start + (bh->b_rsector - ti->begin); ++ ++ return 1; ++} ++ ++static int linear_status(struct dm_target *ti, status_type_t type, ++ char *result, int maxlen) ++{ ++ struct linear_c *lc = (struct linear_c *) ti->private; ++ ++ switch (type) { ++ case STATUSTYPE_INFO: ++ result[0] = '\0'; ++ break; ++ ++ case STATUSTYPE_TABLE: ++ snprintf(result, maxlen, "%s " SECTOR_FORMAT, ++ kdevname(to_kdev_t(lc->dev->bdev->bd_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-2.4.20/drivers/md/dm-snapshot.c linux/drivers/md/dm-snapshot.c +--- linux-2.4.20/drivers/md/dm-snapshot.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-snapshot.c Wed Mar 26 14:12:59 2003 +@@ -0,0 +1,1170 @@ ++/* ++ * dm-snapshot.c ++ * ++ * Copyright (C) 2001-2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#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 ++ ++/* ++ * 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) ++{ ++ sector_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; ++} ++ ++/* ++ * 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:

++ */ ++static int snapshot_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ struct dm_snapshot *s; ++ unsigned long chunk_size; ++ int r = -EINVAL; ++ char persistent; ++ char *origin_path; ++ char *cow_path; ++ char *value; ++ int blocksize; ++ ++ if (argc < 4) { ++ ti->error = "dm-snapshot: requires exactly 4 arguments"; ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ origin_path = argv[0]; ++ cow_path = argv[1]; ++ persistent = toupper(*argv[2]); ++ ++ if (persistent != 'P' && persistent != 'N') { ++ ti->error = "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) { ++ ti->error = "Invalid chunk size"; ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ s = kmalloc(sizeof(*s), GFP_KERNEL); ++ if (s == NULL) { ++ ti->error = "Cannot allocate snapshot context private " ++ "structure"; ++ r = -ENOMEM; ++ goto bad; ++ } ++ ++ r = dm_get_device(ti, origin_path, 0, ti->len, FMODE_READ, &s->origin); ++ if (r) { ++ ti->error = "Cannot get origin device"; ++ goto bad_free; ++ } ++ ++ /* FIXME: get cow length */ ++ r = dm_get_device(ti, cow_path, 0, 0, ++ FMODE_READ | FMODE_WRITE, &s->cow); ++ if (r) { ++ dm_put_device(ti, s->origin); ++ ti->error = "Cannot get COW device"; ++ goto bad_free; ++ } ++ ++ /* ++ * 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); ++ if (chunk_size % (blocksize / SECTOR_SIZE)) { ++ ti->error = "Chunk 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) { ++ ti->error = "Chunk size is too big"; ++ r = -EINVAL; ++ goto bad_putdev; ++ } ++ ++ /* Check chunk_size is a power of 2 */ ++ if (chunk_size & (chunk_size - 1)) { ++ ti->error = "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; ++ init_rwsem(&s->lock); ++ s->table = ti->table; ++ ++ /* Allocate hash table for COW data */ ++ if (init_hash_tables(s)) { ++ ti->error = "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 == 'P') ++ r = dm_create_persistent(&s->store, s->chunk_size); ++ else ++ r = dm_create_transient(&s->store, s, blocksize); ++ ++ if (r) { ++ ti->error = "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; ++ ti->error = "Cannot register snapshot origin"; ++ goto bad_free2; ++ } ++#if LVM_VFS_ENHANCEMENT ++ unlockfs(s->origin->dev); ++#endif ++ kcopyd_inc_client_count(); ++ ++ ti->private = s; ++ return 0; ++ ++ bad_free2: ++#if LVM_VFS_ENHANCEMENT ++ unlockfs(s->origin->dev); ++#endif ++ s->store.destroy(&s->store); ++ ++ bad_free1: ++ exit_exception_table(&s->pending, pending_cache); ++ exit_exception_table(&s->complete, exception_cache); ++ ++ bad_putdev: ++ dm_put_device(ti, s->cow); ++ dm_put_device(ti, s->origin); ++ ++ bad_free: ++ kfree(s); ++ ++ bad: ++ return r; ++} ++ ++static void snapshot_dtr(struct dm_target *ti) ++{ ++ struct dm_snapshot *s = (struct dm_snapshot *) ti->private; ++ ++ dm_table_event(ti->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_put_device(ti, s->origin); ++ dm_put_device(ti, 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 dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ struct exception *e; ++ struct dm_snapshot *s = (struct dm_snapshot *) ti->private; ++ 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(struct dm_target *ti, status_type_t type, ++ char *result, int maxlen) ++{ ++ struct dm_snapshot *snap = (struct dm_snapshot *) ti->private; ++ 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: ++ * The context for an origin is merely a 'struct dm_dev *' ++ * pointing to the real device. ++ */ ++static int origin_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ int r; ++ struct dm_dev *dev; ++ ++ if (argc != 1) { ++ ti->error = "dm-origin: incorrect number of arguments"; ++ return -EINVAL; ++ } ++ ++ r = dm_get_device(ti, argv[0], 0, ti->len, ++ dm_table_get_mode(ti->table), &dev); ++ if (r) { ++ ti->error = "Cannot get target device"; ++ return r; ++ } ++ ++ ti->private = dev; ++ ++ return 0; ++} ++ ++static void origin_dtr(struct dm_target *ti) ++{ ++ struct dm_dev *dev = (struct dm_dev *) ti->private; ++ dm_put_device(ti, dev); ++} ++ ++static int origin_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ struct dm_dev *dev = (struct dm_dev *) ti->private; ++ 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(struct dm_target *ti, status_type_t type, char *result, ++ int maxlen) ++{ ++ struct dm_dev *dev = (struct dm_dev *) ti->private; ++ ++ 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, ++}; ++ ++static struct target_type snapshot_target = { ++ name: "snapshot", ++ module: THIS_MODULE, ++ ctr: snapshot_ctr, ++ dtr: snapshot_dtr, ++ map: snapshot_map, ++ status: snapshot_status, ++}; ++ ++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-2.4.20/drivers/md/dm-snapshot.h linux/drivers/md/dm-snapshot.h +--- linux-2.4.20/drivers/md/dm-snapshot.h Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-snapshot.h Wed Mar 26 12:53:19 2003 +@@ -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 ++ ++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 sector_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); ++ ++/* ++ * Return the number of sectors in the device. ++ */ ++static inline sector_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, sector_t sector) ++{ ++ return (sector & ~s->chunk_mask) >> s->chunk_shift; ++} ++ ++static inline sector_t chunk_to_sector(struct dm_snapshot *s, chunk_t chunk) ++{ ++ return chunk << s->chunk_shift; ++} ++ ++#endif +diff -ruN linux-2.4.20/drivers/md/dm-stripe.c linux/drivers/md/dm-stripe.c +--- linux-2.4.20/drivers/md/dm-stripe.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-stripe.c Wed Mar 26 14:07:57 2003 +@@ -0,0 +1,257 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++ ++struct stripe { ++ struct dm_dev *dev; ++ sector_t physical_start; ++}; ++ ++struct stripe_c { ++ uint32_t stripes; ++ ++ /* The size of this target / num. stripes */ ++ uint32_t stripe_width; ++ ++ /* stripe chunk size */ ++ uint32_t chunk_shift; ++ sector_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 pair ++ */ ++static int get_stripe(struct dm_target *ti, struct stripe_c *sc, ++ int stripe, char **argv) ++{ ++ sector_t start; ++ ++ if (sscanf(argv[1], SECTOR_FORMAT, &start) != 1) ++ return -EINVAL; ++ ++ if (dm_get_device(ti, argv[0], start, sc->stripe_width, ++ dm_table_get_mode(ti->table), ++ &sc->stripe[stripe].dev)) ++ return -ENXIO; ++ ++ sc->stripe[stripe].physical_start = start; ++ return 0; ++} ++ ++/* ++ * FIXME: Nasty function, only present because we can't link ++ * against __moddi3 and __divdi3. ++ * ++ * returns a == b * n ++ */ ++static int multiple(sector_t a, sector_t b, sector_t *n) ++{ ++ sector_t acc, prev, i; ++ ++ *n = 0; ++ while (a >= b) { ++ for (acc = b, prev = 0, i = 1; ++ acc <= a; ++ prev = acc, acc <<= 1, i <<= 1) ++ ; ++ ++ a -= prev; ++ *n += i >> 1; ++ } ++ ++ return a == 0; ++} ++ ++/* ++ * Construct a striped mapping. ++ * [ ]+ ++ */ ++static int stripe_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ struct stripe_c *sc; ++ sector_t width; ++ uint32_t stripes; ++ uint32_t chunk_size; ++ char *end; ++ int r, i; ++ ++ if (argc < 2) { ++ ti->error = "dm-stripe: Not enough arguments"; ++ return -EINVAL; ++ } ++ ++ stripes = simple_strtoul(argv[0], &end, 10); ++ if (*end) { ++ ti->error = "dm-stripe: Invalid stripe count"; ++ return -EINVAL; ++ } ++ ++ chunk_size = simple_strtoul(argv[1], &end, 10); ++ if (*end) { ++ ti->error = "dm-stripe: Invalid chunk_size"; ++ return -EINVAL; ++ } ++ ++ /* ++ * chunk_size is a power of two ++ */ ++ if (!chunk_size || (chunk_size & (chunk_size - 1))) { ++ ti->error = "dm-stripe: Invalid chunk size"; ++ return -EINVAL; ++ } ++ ++ if (!multiple(ti->len, stripes, &width)) { ++ ti->error = "dm-stripe: Target length not divisable by " ++ "number of stripes"; ++ return -EINVAL; ++ } ++ ++ /* ++ * Do we have enough arguments for that many stripes ? ++ */ ++ if (argc != (2 + 2 * stripes)) { ++ ti->error = "dm-stripe: Not enough destinations specified"; ++ return -EINVAL; ++ } ++ ++ sc = alloc_context(stripes); ++ if (!sc) { ++ ti->error = "dm-stripe: Memory allocation for striped context " ++ "failed"; ++ return -ENOMEM; ++ } ++ ++ sc->stripes = stripes; ++ sc->stripe_width = width; ++ ++ sc->chunk_mask = ((sector_t) 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++) { ++ argv += 2; ++ ++ r = get_stripe(ti, sc, i, argv); ++ if (r < 0) { ++ ti->error = "dm-stripe: Couldn't parse stripe " ++ "destination"; ++ while (i--) ++ dm_put_device(ti, sc->stripe[i].dev); ++ kfree(sc); ++ return r; ++ } ++ } ++ ++ ti->private = sc; ++ return 0; ++} ++ ++static void stripe_dtr(struct dm_target *ti) ++{ ++ unsigned int i; ++ struct stripe_c *sc = (struct stripe_c *) ti->private; ++ ++ for (i = 0; i < sc->stripes; i++) ++ dm_put_device(ti, sc->stripe[i].dev); ++ ++ kfree(sc); ++} ++ ++static int stripe_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **context) ++{ ++ struct stripe_c *sc = (struct stripe_c *) ti->private; ++ ++ sector_t offset = bh->b_rsector - ti->begin; ++ 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(struct dm_target *ti, ++ status_type_t type, char *result, int maxlen) ++{ ++ struct stripe_c *sc = (struct stripe_c *) ti->private; ++ int offset; ++ int i; ++ ++ switch (type) { ++ case STATUSTYPE_INFO: ++ result[0] = '\0'; ++ break; ++ ++ case STATUSTYPE_TABLE: ++ offset = snprintf(result, maxlen, "%d " SECTOR_FORMAT, ++ sc->stripes, sc->chunk_mask + 1); ++ for (i = 0; i < sc->stripes; i++) { ++ offset += ++ snprintf(result + offset, maxlen - offset, ++ " %s " SECTOR_FORMAT, ++ kdevname(to_kdev_t(sc->stripe[i].dev->bdev->bd_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-2.4.20/drivers/md/dm-table.c linux/drivers/md/dm-table.c +--- linux-2.4.20/drivers/md/dm-table.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-table.c Wed Mar 26 14:09:13 2003 +@@ -0,0 +1,666 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#define MAX_DEPTH 16 ++#define NODE_SIZE L1_CACHE_BYTES ++#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) ++#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) ++ ++struct dm_table { ++ atomic_t holders; ++ ++ /* btree table */ ++ int depth; ++ int counts[MAX_DEPTH]; /* in nodes */ ++ sector_t *index[MAX_DEPTH]; ++ ++ int num_targets; ++ int num_allocated; ++ sector_t *highs; ++ struct dm_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; ++ ++ /* ++ * A waitqueue for processes waiting for something ++ * interesting to happen to this table. ++ */ ++ wait_queue_head_t eventq; ++}; ++ ++/* ++ * Ceiling(n / size) ++ */ ++static inline unsigned long div_up(unsigned long n, unsigned long size) ++{ ++ return dm_round_up(n, size) / size; ++} ++ ++/* ++ * Similar to ceiling(log_size(n)) ++ */ ++static unsigned int int_log(unsigned long n, unsigned long base) ++{ ++ int result = 0; ++ ++ while (n > 1) { ++ n = div_up(n, base); ++ result++; ++ } ++ ++ return result; ++} ++ ++/* ++ * 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 sector_t *get_node(struct dm_table *t, int l, int n) ++{ ++ return t->index[l] + (n * KEYS_PER_NODE); ++} ++ ++/* ++ * Return the highest key that you could lookup from the n'th ++ * node on level l of the btree. ++ */ ++static sector_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 (sector_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; ++ sector_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) ++{ ++ sector_t *n_highs; ++ struct dm_target *n_targets; ++ int n = t->num_targets; ++ ++ /* ++ * Allocate both the target array and offset array at once. ++ */ ++ n_highs = (sector_t *) vcalloc(sizeof(struct dm_target) + ++ sizeof(sector_t), num); ++ if (!n_highs) ++ return -ENOMEM; ++ ++ n_targets = (struct dm_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)); ++ 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, int mode) ++{ ++ struct dm_table *t = kmalloc(sizeof(*t), GFP_NOIO); ++ ++ if (!t) ++ return -ENOMEM; ++ ++ memset(t, 0, sizeof(*t)); ++ INIT_LIST_HEAD(&t->devices); ++ atomic_set(&t->holders, 1); ++ ++ /* allocate a single nodes worth of targets to begin with */ ++ if (alloc_targets(t, KEYS_PER_NODE)) { ++ kfree(t); ++ t = NULL; ++ return -ENOMEM; ++ } ++ ++ init_waitqueue_head(&t->eventq); ++ t->mode = mode; ++ *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 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 dm_target *tgt = t->targets + i; ++ ++ if (tgt->type->dtr) ++ tgt->type->dtr(tgt); ++ ++ dm_put_target_type(tgt->type); ++ } ++ ++ 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); ++} ++ ++void dm_table_get(struct dm_table *t) ++{ ++ atomic_inc(&t->holders); ++} ++ ++void dm_table_put(struct dm_table *t) ++{ ++ if (atomic_dec_and_test(&t->holders)) ++ table_destroy(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 dev_t. ++ */ ++static 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 out; ++ ++ inode = nd.dentry->d_inode; ++ if (!inode) { ++ r = -ENOENT; ++ goto out; ++ } ++ ++ if (!S_ISBLK(inode->i_mode)) { ++ r = -ENOTBLK; ++ goto out; ++ } ++ ++ *dev = inode->i_rdev; ++ ++ out: ++ 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 (kdev_same(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 *dd) ++{ ++ if (dd->bdev) ++ BUG(); ++ ++ dd->bdev = bdget(kdev_t_to_nr(dd->dev)); ++ if (!dd->bdev) ++ return -ENOMEM; ++ ++ return blkdev_get(dd->bdev, dd->mode, 0, BDEV_RAW); ++} ++ ++/* ++ * Close a device that we've been using. ++ */ ++static void close_dev(struct dm_dev *dd) ++{ ++ if (!dd->bdev) ++ return; ++ ++ blkdev_put(dd->bdev, BDEV_RAW); ++ dd->bdev = 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, sector_t start, sector_t len) ++{ ++ int *sizes; ++ sector_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))); ++} ++ ++/* ++ * 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->bdev = 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_get_device(struct dm_target *ti, const char *path, sector_t start, ++ sector_t len, int mode, struct dm_dev **result) ++{ ++ int r; ++ kdev_t dev; ++ struct dm_dev *dd; ++ int major, minor; ++ struct dm_table *t = ti->table; ++ ++ if (!t) ++ BUG(); ++ ++ if (sscanf(path, "%x:%x", &major, &minor) == 2) { ++ /* Extract the major/minor numbers */ ++ dev = mk_kdev(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->mode = mode; ++ dd->bdev = NULL; ++ ++ if ((r = open_dev(dd))) { ++ kfree(dd); ++ return r; ++ } ++ ++ 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); ++ ++ if (!check_device_area(dd->dev, start, len)) { ++ DMWARN("device %s too small for target", path); ++ dm_put_device(ti, dd); ++ return -EINVAL; ++ } ++ ++ *result = dd; ++ ++ return 0; ++} ++ ++/* ++ * Decrement a devices use count and remove it if neccessary. ++ */ ++void dm_put_device(struct dm_target *ti, struct dm_dev *dd) ++{ ++ if (atomic_dec_and_test(&dd->count)) { ++ close_dev(dd); ++ list_del(&dd->list); ++ kfree(dd); ++ } ++} ++ ++/* ++ * Checks to see if the target joins onto the end of the table. ++ */ ++static int adjoin(struct dm_table *table, struct dm_target *ti) ++{ ++ struct dm_target *prev; ++ ++ if (!table->num_targets) ++ return !ti->begin; ++ ++ prev = &table->targets[table->num_targets - 1]; ++ return (ti->begin == (prev->begin + prev->len)); ++} ++ ++/* ++ * Destructively splits up the argument list to pass to ctr. ++ */ ++static 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; ++} ++ ++int dm_table_add_target(struct dm_table *t, const char *type, ++ sector_t start, sector_t len, char *params) ++{ ++ int r = -EINVAL, argc; ++ char *argv[32]; ++ struct dm_target *tgt; ++ ++ if ((r = check_space(t))) ++ return r; ++ ++ tgt = t->targets + t->num_targets; ++ memset(tgt, 0, sizeof(*tgt)); ++ ++ tgt->type = dm_get_target_type(type); ++ if (!tgt->type) { ++ tgt->error = "unknown target type"; ++ return -EINVAL; ++ } ++ ++ tgt->table = t; ++ tgt->begin = start; ++ tgt->len = len; ++ tgt->error = "Unknown error"; ++ ++ /* ++ * Does this target adjoin the previous one ? ++ */ ++ if (!adjoin(t, tgt)) { ++ tgt->error = "Gap in table"; ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ r = split_args(ARRAY_SIZE(argv), &argc, argv, params); ++ if (r) { ++ tgt->error = "couldn't split parameters"; ++ goto bad; ++ } ++ ++ r = tgt->type->ctr(tgt, argc, argv); ++ if (r) ++ goto bad; ++ ++ t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; ++ return 0; ++ ++ bad: ++ printk(KERN_ERR DM_NAME ": %s\n", tgt->error); ++ dm_put_target_type(tgt->type); ++ return r; ++} ++ ++static int setup_indexes(struct dm_table *t) ++{ ++ int i, total = 0; ++ sector_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 = (sector_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); ++} ++ ++sector_t dm_table_get_size(struct dm_table *t) ++{ ++ return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; ++} ++ ++struct dm_target *dm_table_get_target(struct dm_table *t, int index) ++{ ++ if (index > t->num_targets) ++ return NULL; ++ ++ return t->targets + index; ++} ++ ++/* ++ * Search the btree for the correct target. ++ */ ++struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) ++{ ++ int l, n = 0, k = 0; ++ sector_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] >= sector) ++ break; ++ } ++ ++ return &t->targets[(KEYS_PER_NODE * n) + k]; ++} ++ ++unsigned int dm_table_get_num_targets(struct dm_table *t) ++{ ++ return t->num_targets; ++} ++ ++struct list_head *dm_table_get_devices(struct dm_table *t) ++{ ++ return &t->devices; ++} ++ ++int dm_table_get_mode(struct dm_table *t) ++{ ++ return t->mode; ++} ++ ++void dm_table_add_wait_queue(struct dm_table *t, wait_queue_t *wq) ++{ ++ add_wait_queue(&t->eventq, wq); ++} ++ ++EXPORT_SYMBOL(dm_get_device); ++EXPORT_SYMBOL(dm_put_device); ++EXPORT_SYMBOL(dm_table_event); ++EXPORT_SYMBOL(dm_table_get_mode); +diff -ruN linux-2.4.20/drivers/md/dm-target.c linux/drivers/md/dm-target.c +--- linux-2.4.20/drivers/md/dm-target.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-target.c Wed Mar 26 12:54:14 2003 +@@ -0,0 +1,187 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++ ++struct tt_internal { ++ struct target_type tt; ++ ++ struct list_head list; ++ long use; ++}; ++ ++static LIST_HEAD(_targets); ++static DECLARE_RWSEM(_lock); ++ ++#define DM_MOD_NAME_SIZE 32 ++ ++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; ++ ++ down_read(&_lock); ++ ti = __find_target_type(name); ++ ++ if (ti) { ++ if (ti->use == 0 && ti->tt.module) ++ __MOD_INC_USE_COUNT(ti->tt.module); ++ ti->use++; ++ } ++ up_read(&_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); ++} ++ ++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; ++ ++ down_read(&_lock); ++ if (--ti->use == 0 && ti->tt.module) ++ __MOD_DEC_USE_COUNT(ti->tt.module); ++ ++ if (ti->use < 0) ++ BUG(); ++ up_read(&_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; ++ ++ down_write(&_lock); ++ if (__find_target_type(t->name)) ++ rv = -EEXIST; ++ else ++ list_add(&ti->list, &_targets); ++ ++ up_write(&_lock); ++ return rv; ++} ++ ++int dm_unregister_target(struct target_type *t) ++{ ++ struct tt_internal *ti; ++ ++ down_write(&_lock); ++ if (!(ti = __find_target_type(t->name))) { ++ up_write(&_lock); ++ return -EINVAL; ++ } ++ ++ if (ti->use) { ++ up_write(&_lock); ++ return -ETXTBSY; ++ } ++ ++ list_del(&ti->list); ++ kfree(ti); ++ ++ up_write(&_lock); ++ return 0; ++} ++ ++/* ++ * io-err: always fails an io, useful for bringing ++ * up LVs that have holes in them. ++ */ ++static int io_err_ctr(struct dm_target *ti, int argc, char **args) ++{ ++ return 0; ++} ++ ++static void io_err_dtr(struct dm_target *ti) ++{ ++ /* empty */ ++} ++ ++static int io_err_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ return -EIO; ++} ++ ++static struct target_type error_target = { ++ .name = "error", ++ .ctr = io_err_ctr, ++ .dtr = io_err_dtr, ++ .map = io_err_map, ++}; ++ ++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-2.4.20/drivers/md/dm.c linux/drivers/md/dm.c +--- linux-2.4.20/drivers/md/dm.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm.c Wed Mar 26 14:23:27 2003 +@@ -0,0 +1,878 @@ ++/* ++ * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include ++ ++static const char *_name = DM_NAME; ++#define MAX_DEVICES (1 << MINORBITS) ++#define DEFAULT_READ_AHEAD 64 ++ ++static int major = 0; ++static int _major = 0; ++ ++struct dm_io { ++ struct mapped_device *md; ++ ++ struct dm_target *ti; ++ int rw; ++ void *map_context; ++ void (*end_io) (struct buffer_head * bh, int uptodate); ++ void *context; ++}; ++ ++struct deferred_io { ++ int rw; ++ struct buffer_head *bh; ++ struct deferred_io *next; ++}; ++ ++/* ++ * Bits for the md->flags field. ++ */ ++#define DMF_BLOCK_IO 0 ++#define DMF_SUSPENDED 1 ++ ++struct mapped_device { ++ struct rw_semaphore lock; ++ atomic_t holders; ++ ++ kdev_t dev; ++ unsigned long flags; ++ ++ /* ++ * A list of ios that arrived while we were suspended. ++ */ ++ atomic_t pending; ++ wait_queue_head_t wait; ++ struct deferred_io *deferred; ++ ++ /* ++ * The current mapping. ++ */ ++ struct dm_table *map; ++ ++ /* ++ * io objects are allocated from here. ++ */ ++ mempool_t *io_pool; ++}; ++ ++#define MIN_IOS 256 ++static kmem_cache_t *_io_cache; ++ ++/* block device arrays */ ++static int _block_size[MAX_DEVICES]; ++static int _blksize_size[MAX_DEVICES]; ++static int _hardsect_size[MAX_DEVICES]; ++ ++static struct mapped_device *get_kdev(kdev_t dev); ++static int dm_request(request_queue_t *q, int rw, struct buffer_head *bh); ++static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb); ++ ++static __init int local_init(void) ++{ ++ int r; ++ ++ /* allocate a slab for the dm_ios */ ++ _io_cache = kmem_cache_create("dm io", ++ sizeof(struct dm_io), 0, 0, NULL, NULL); ++ ++ if (!_io_cache) ++ return -ENOMEM; ++ ++ _major = major; ++ r = register_blkdev(_major, _name, &dm_blk_dops); ++ if (r < 0) { ++ DMERR("register_blkdev failed"); ++ kmem_cache_destroy(_io_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), dm_request); ++ ++ return 0; ++} ++ ++static void local_exit(void) ++{ ++ kmem_cache_destroy(_io_cache); ++ ++ if (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) ++ xx(dm_linear) ++ xx(dm_stripe) ++ xx(dm_snapshot) ++ xx(dm_interface) ++#undef xx ++}; ++ ++static int __init dm_init(void) ++{ ++ const int count = ARRAY_SIZE(_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 = ARRAY_SIZE(_inits); ++ ++ while (i--) ++ _inits[i].exit(); ++} ++ ++/* ++ * Block device functions ++ */ ++static int dm_blk_open(struct inode *inode, struct file *file) ++{ ++ struct mapped_device *md; ++ ++ md = get_kdev(inode->i_rdev); ++ if (!md) ++ return -ENXIO; ++ ++ return 0; ++} ++ ++static int dm_blk_close(struct inode *inode, struct file *file) ++{ ++ struct mapped_device *md; ++ ++ md = get_kdev(inode->i_rdev); ++ dm_put(md); /* put the reference gained by dm_blk_open */ ++ dm_put(md); ++ return 0; ++} ++ ++static inline struct dm_io *alloc_io(struct mapped_device *md) ++{ ++ return mempool_alloc(md->io_pool, GFP_NOIO); ++} ++ ++static inline void free_io(struct mapped_device *md, struct dm_io *io) ++{ ++ mempool_free(io, md->io_pool); ++} ++ ++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); ++} ++ ++/* In 512-byte units */ ++#define VOLUME_SIZE(minor) (_block_size[(minor)] << 1) ++ ++/* FIXME: check this */ ++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; ++} ++ ++/* ++ * Add the buffer to the list of deferred io. ++ */ ++static int queue_io(struct mapped_device *md, struct buffer_head *bh, int rw) ++{ ++ struct deferred_io *di; ++ ++ di = alloc_deferred(); ++ if (!di) ++ return -ENOMEM; ++ ++ down_write(&md->lock); ++ ++ if (!test_bit(DMF_BLOCK_IO, &md->flags)) { ++ up_write(&md->lock); ++ free_deferred(di); ++ return 1; ++ } ++ ++ di->bh = bh; ++ di->rw = rw; ++ di->next = md->deferred; ++ md->deferred = di; ++ ++ up_write(&md->lock); ++ return 0; /* deferred successfully */ ++} ++ ++/* ++ * 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) ++{ ++ int r; ++ struct dm_io *io = bh->b_private; ++ dm_endio_fn endio = io->ti->type->end_io; ++ ++ if (endio) { ++ r = endio(io->ti, bh, io->rw, uptodate ? 0 : -EIO, ++ io->map_context); ++ if (r < 0) ++ uptodate = 0; ++ ++ else if (r > 0) ++ /* the target wants another shot at the io */ ++ return; ++ } ++ ++ if (atomic_dec_and_test(&io->md->pending)) ++ /* nudge anyone waiting on suspend queue */ ++ wake_up(&io->md->wait); ++ ++ bh->b_end_io = io->end_io; ++ bh->b_private = io->context; ++ free_io(io->md, io); ++ ++ bh->b_end_io(bh, uptodate); ++} ++ ++/* ++ * Do the bh mapping for a given leaf ++ */ ++static inline int __map_buffer(struct mapped_device *md, int rw, ++ struct buffer_head *bh, struct dm_io *io) ++{ ++ struct dm_target *ti; ++ ++ ti = dm_table_find_target(md->map, bh->b_rsector); ++ if (!ti || !ti->type) ++ return -EINVAL; ++ ++ /* hook the end io request fn */ ++ atomic_inc(&md->pending); ++ io->md = md; ++ io->ti = ti; ++ io->rw = rw; ++ io->end_io = bh->b_end_io; ++ io->context = bh->b_private; ++ bh->b_end_io = dec_pending; ++ bh->b_private = io; ++ ++ return ti->type->map(ti, bh, rw, &io->map_context); ++} ++ ++/* ++ * Checks to see if we should be deferring io, if so it queues it ++ * and returns 1. ++ */ ++static inline int __deferring(struct mapped_device *md, int rw, ++ struct buffer_head *bh) ++{ ++ int r; ++ ++ /* ++ * If we're suspended we have to queue this io for later. ++ */ ++ while (test_bit(DMF_BLOCK_IO, &md->flags)) { ++ up_read(&md->lock); ++ ++ /* ++ * There's no point deferring a read ahead ++ * request, just drop it. ++ */ ++ if (rw == READA) { ++ down_read(&md->lock); ++ return -EIO; ++ } ++ ++ r = queue_io(md, bh, rw); ++ down_read(&md->lock); ++ ++ if (r < 0) ++ return r; ++ ++ if (r == 0) ++ return 1; /* deferred successfully */ ++ ++ } ++ ++ return 0; ++} ++ ++static int dm_request(request_queue_t *q, int rw, struct buffer_head *bh) ++{ ++ int r; ++ struct dm_io *io; ++ struct mapped_device *md; ++ ++ md = get_kdev(bh->b_rdev); ++ if (!md) { ++ buffer_IO_error(bh); ++ return 0; ++ } ++ ++ io = alloc_io(md); ++ down_read(&md->lock); ++ ++ r = __deferring(md, rw, bh); ++ if (r < 0) ++ goto bad; ++ ++ else if (!r) { ++ /* not deferring */ ++ r = __map_buffer(md, rw, bh, io); ++ if (r < 0) ++ goto bad; ++ } else ++ r = 0; ++ ++ up_read(&md->lock); ++ dm_put(md); ++ return r; ++ ++ bad: ++ buffer_IO_error(bh); ++ up_read(&md->lock); ++ dm_put(md); ++ return 0; ++} ++ ++static int check_dev_size(kdev_t dev, unsigned long block) ++{ ++ /* FIXME: check this */ ++ int minor = MINOR(dev); ++ 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 __bmap(struct mapped_device *md, kdev_t dev, unsigned long block, ++ kdev_t *r_dev, unsigned long *r_block) ++{ ++ struct buffer_head bh; ++ struct dm_target *ti; ++ void *map_context; ++ int r; ++ ++ if (test_bit(DMF_BLOCK_IO, &md->flags)) { ++ return -EPERM; ++ } ++ ++ if (!check_dev_size(dev, block)) { ++ 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(dev)]; ++ bh.b_rsector = block * (bh.b_size >> 9); ++ ++ /* find target */ ++ ti = dm_table_find_target(md->map, bh.b_rsector); ++ ++ /* do the mapping */ ++ r = ti->type->map(ti, &bh, READ, &map_context); ++ ti->type->end_io(ti, &bh, READ, 0, map_context); ++ ++ if (!r) { ++ *r_dev = bh.b_rdev; ++ *r_block = bh.b_rsector / (bh.b_size >> 9); ++ } ++ ++ return r; ++} ++ ++/* ++ * Marshals arguments and results between user and kernel space. ++ */ ++static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb) ++{ ++ struct mapped_device *md; ++ unsigned long block, r_block; ++ kdev_t r_dev; ++ int r; ++ ++ if (get_user(block, &lvb->lv_block)) ++ return -EFAULT; ++ ++ md = get_kdev(inode->i_rdev); ++ if (!md) ++ return -ENXIO; ++ ++ down_read(&md->lock); ++ r = __bmap(md, inode->i_rdev, block, &r_dev, &r_block); ++ up_read(&md->lock); ++ dm_put(md); ++ ++ if (!r && (put_user(kdev_t_to_nr(r_dev), &lvb->lv_dev) || ++ put_user(r_block, &lvb->lv_block))) ++ r = -EFAULT; ++ ++ return r; ++} ++ ++/*----------------------------------------------------------------- ++ * A bitset is used to keep track of allocated minor numbers. ++ *---------------------------------------------------------------*/ ++static spinlock_t _minor_lock = SPIN_LOCK_UNLOCKED; ++static struct mapped_device *_mds[MAX_DEVICES]; ++ ++static void free_minor(int minor) ++{ ++ spin_lock(&_minor_lock); ++ _mds[minor] = NULL; ++ spin_unlock(&_minor_lock); ++} ++ ++/* ++ * See if the device with a specific minor # is free. ++ */ ++static int specific_minor(int minor, struct mapped_device *md) ++{ ++ int r = -EBUSY; ++ ++ if (minor >= MAX_DEVICES) { ++ DMWARN("request for a mapped_device beyond MAX_DEVICES (%d)", ++ MAX_DEVICES); ++ return -EINVAL; ++ } ++ ++ spin_lock(&_minor_lock); ++ if (!_mds[minor]) { ++ _mds[minor] = md; ++ r = minor; ++ } ++ spin_unlock(&_minor_lock); ++ ++ return r; ++} ++ ++static int next_free_minor(struct mapped_device *md) ++{ ++ int i; ++ ++ spin_lock(&_minor_lock); ++ for (i = 0; i < MAX_DEVICES; i++) { ++ if (!_mds[i]) { ++ _mds[i] = md; ++ break; ++ } ++ } ++ spin_unlock(&_minor_lock); ++ ++ return (i < MAX_DEVICES) ? i : -EBUSY; ++} ++ ++static struct mapped_device *get_kdev(kdev_t dev) ++{ ++ struct mapped_device *md; ++ ++ if (major(dev) != _major) ++ return NULL; ++ ++ spin_lock(&_minor_lock); ++ md = _mds[minor(dev)]; ++ if (md) ++ dm_get(md); ++ spin_unlock(&_minor_lock); ++ ++ return md; ++} ++ ++/* ++ * Allocate and initialise a blank device with a given minor. ++ */ ++static struct mapped_device *alloc_dev(int minor) ++{ ++ struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); ++ ++ if (!md) { ++ DMWARN("unable to allocate device, out of memory."); ++ return NULL; ++ } ++ ++ /* get a minor number for the dev */ ++ minor = (minor < 0) ? next_free_minor(md) : specific_minor(minor, md); ++ if (minor < 0) { ++ kfree(md); ++ return NULL; ++ } ++ ++ memset(md, 0, sizeof(*md)); ++ ++ md->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab, ++ mempool_free_slab, _io_cache); ++ if (!md->io_pool) { ++ free_minor(minor); ++ kfree(md); ++ return NULL; ++ } ++ ++ md->dev = mk_kdev(_major, minor); ++ init_rwsem(&md->lock); ++ atomic_set(&md->holders, 1); ++ atomic_set(&md->pending, 0); ++ init_waitqueue_head(&md->wait); ++ ++ return md; ++} ++ ++static void free_dev(struct mapped_device *md) ++{ ++ free_minor(minor(md->dev)); ++ mempool_destroy(md->io_pool); ++ kfree(md); ++} ++ ++/* ++ * The hardsect size for a mapped device is the largest hardsect size ++ * from the devices it maps onto. ++ */ ++static int __find_hardsect_size(struct list_head *devices) ++{ ++ int result = 512, 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; ++ ++ /* in k */ ++ _block_size[minor] = dm_table_get_size(t) >> 1; ++ _blksize_size[minor] = BLOCK_SIZE; ++ _hardsect_size[minor] = __find_hardsect_size(dm_table_get_devices(t)); ++ register_disk(NULL, md->dev, 1, &dm_blk_dops, _block_size[minor]); ++ ++ dm_table_get(t); ++ return 0; ++} ++ ++static void __unbind(struct mapped_device *md) ++{ ++ int minor = minor(md->dev); ++ ++ dm_table_put(md->map); ++ md->map = NULL; ++ ++ _block_size[minor] = 0; ++ _blksize_size[minor] = 0; ++ _hardsect_size[minor] = 0; ++} ++ ++/* ++ * Constructor for a new device. ++ */ ++int dm_create(int minor, struct dm_table *table, struct mapped_device **result) ++{ ++ int r; ++ struct mapped_device *md; ++ ++ md = alloc_dev(minor); ++ if (!md) ++ return -ENXIO; ++ ++ r = __bind(md, table); ++ if (r) { ++ free_dev(md); ++ return r; ++ } ++ ++ *result = md; ++ return 0; ++} ++ ++void dm_get(struct mapped_device *md) ++{ ++ atomic_inc(&md->holders); ++} ++ ++void dm_put(struct mapped_device *md) ++{ ++ if (atomic_dec_and_test(&md->holders)) { ++ __unbind(md); ++ free_dev(md); ++ } ++} ++ ++/* ++ * Requeue the deferred io 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). ++ */ ++int dm_swap_table(struct mapped_device *md, struct dm_table *table) ++{ ++ int r; ++ ++ down_write(&md->lock); ++ ++ /* device must be suspended */ ++ if (!test_bit(DMF_SUSPENDED, &md->flags)) { ++ up_write(&md->lock); ++ return -EPERM; ++ } ++ ++ __unbind(md); ++ r = __bind(md, table); ++ if (r) ++ return r; ++ ++ up_write(&md->lock); ++ 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 io and ensure that any further io gets deferred. ++ */ ++int dm_suspend(struct mapped_device *md) ++{ ++ DECLARE_WAITQUEUE(wait, current); ++ ++ down_write(&md->lock); ++ ++ /* ++ * First we set the BLOCK_IO flag so no more ios will be ++ * mapped. ++ */ ++ if (test_bit(DMF_BLOCK_IO, &md->flags)) { ++ up_write(&md->lock); ++ return -EINVAL; ++ } ++ ++ set_bit(DMF_BLOCK_IO, &md->flags); ++ add_wait_queue(&md->wait, &wait); ++ up_write(&md->lock); ++ ++ /* ++ * Then we wait for the already mapped ios to ++ * complete. ++ */ ++ run_task_queue(&tq_disk); ++ while (1) { ++ set_current_state(TASK_INTERRUPTIBLE); ++ ++ if (!atomic_read(&md->pending)) ++ break; ++ ++ schedule(); ++ } ++ ++ current->state = TASK_RUNNING; ++ ++ down_write(&md->lock); ++ remove_wait_queue(&md->wait, &wait); ++ set_bit(DMF_SUSPENDED, &md->flags); ++ up_write(&md->lock); ++ ++ return 0; ++} ++ ++int dm_resume(struct mapped_device *md) ++{ ++ struct deferred_io *def; ++ ++ down_write(&md->lock); ++ if (!test_bit(DMF_SUSPENDED, &md->flags) || ++ !dm_table_get_size(md->map)) { ++ up_write(&md->lock); ++ return -EINVAL; ++ } ++ ++ clear_bit(DMF_SUSPENDED, &md->flags); ++ clear_bit(DMF_BLOCK_IO, &md->flags); ++ def = md->deferred; ++ md->deferred = NULL; ++ up_write(&md->lock); ++ ++ flush_deferred_io(def); ++ run_task_queue(&tq_disk); ++ ++ return 0; ++} ++ ++struct dm_table *dm_get_table(struct mapped_device *md) ++{ ++ struct dm_table *t; ++ ++ down_read(&md->lock); ++ t = md->map; ++ dm_table_get(t); ++ up_read(&md->lock); ++ ++ return t; ++} ++ ++kdev_t dm_kdev(struct mapped_device *md) ++{ ++ kdev_t dev; ++ ++ down_read(&md->lock); ++ dev = md->dev; ++ up_read(&md->lock); ++ ++ return dev; ++} ++ ++int dm_suspended(struct mapped_device *md) ++{ ++ return test_bit(DMF_SUSPENDED, &md->flags); ++} ++ ++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 "); ++MODULE_LICENSE("GPL"); +diff -ruN linux-2.4.20/drivers/md/dm.h linux/drivers/md/dm.h +--- linux-2.4.20/drivers/md/dm.h Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm.h Wed Mar 26 14:12:00 2003 +@@ -0,0 +1,154 @@ ++/* ++ * Internal header file for device mapper ++ * ++ * Copyright (C) 2001, 2002 Sistina Software ++ * ++ * This file is released under the LGPL. ++ */ ++ ++#ifndef DM_INTERNAL_H ++#define DM_INTERNAL_H ++ ++#include ++#include ++#include ++#include ++ ++#define DM_NAME "device-mapper" ++#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) ++ ++/* ++ * FIXME: I think this should be with the definition of sector_t ++ * in types.h. ++ */ ++#ifdef CONFIG_LBD ++#define SECTOR_FORMAT "%Lu" ++#else ++#define SECTOR_FORMAT "%lu" ++#endif ++ ++#define SECTOR_SHIFT 9 ++#define SECTOR_SIZE (1 << SECTOR_SHIFT) ++ ++extern struct block_device_operations dm_blk_dops; ++ ++/* ++ * List of devices that a metadevice uses and should open/close. ++ */ ++struct dm_dev { ++ struct list_head list; ++ ++ atomic_t count; ++ int mode; ++ kdev_t dev; ++ struct block_device *bdev; ++}; ++ ++struct dm_table; ++struct mapped_device; ++ ++/*----------------------------------------------------------------- ++ * Functions for manipulating a struct mapped_device. ++ * Drop the reference with dm_put when you finish with the object. ++ *---------------------------------------------------------------*/ ++int dm_create(int minor, struct dm_table *table, struct mapped_device **md); ++ ++/* ++ * Reference counting for md. ++ */ ++void dm_get(struct mapped_device *md); ++void dm_put(struct mapped_device *md); ++ ++/* ++ * 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); ++ ++/* ++ * The device must be suspended before calling this method. ++ */ ++int dm_swap_table(struct mapped_device *md, struct dm_table *t); ++ ++/* ++ * Drop a reference on the table when you've finished with the ++ * result. ++ */ ++struct dm_table *dm_get_table(struct mapped_device *md); ++ ++/* ++ * Info functions. ++ */ ++kdev_t dm_kdev(struct mapped_device *md); ++int dm_suspended(struct mapped_device *md); ++ ++/*----------------------------------------------------------------- ++ * Functions for manipulating a table. Tables are also reference ++ * counted. ++ *---------------------------------------------------------------*/ ++int dm_table_create(struct dm_table **result, int mode); ++ ++void dm_table_get(struct dm_table *t); ++void dm_table_put(struct dm_table *t); ++ ++int dm_table_add_target(struct dm_table *t, const char *type, ++ sector_t start, sector_t len, char *params); ++int dm_table_complete(struct dm_table *t); ++void dm_table_event(struct dm_table *t); ++sector_t dm_table_get_size(struct dm_table *t); ++struct dm_target *dm_table_get_target(struct dm_table *t, int index); ++struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); ++unsigned int dm_table_get_num_targets(struct dm_table *t); ++struct list_head *dm_table_get_devices(struct dm_table *t); ++int dm_table_get_mode(struct dm_table *t); ++void dm_table_add_wait_queue(struct dm_table *t, wait_queue_t *wq); ++ ++/*----------------------------------------------------------------- ++ * A registry of target types. ++ *---------------------------------------------------------------*/ ++int dm_target_init(void); ++void dm_target_exit(void); ++struct target_type *dm_get_target_type(const char *name); ++void dm_put_target_type(struct target_type *t); ++ ++ ++/*----------------------------------------------------------------- ++ * Useful inlines. ++ *---------------------------------------------------------------*/ ++static inline int array_too_big(unsigned long fixed, unsigned long obj, ++ unsigned long num) ++{ ++ return (num > (ULONG_MAX - fixed) / obj); ++} ++ ++/* ++ * ceiling(n / size) * size ++ */ ++static inline unsigned long dm_round_up(unsigned long n, unsigned long size) ++{ ++ unsigned long r = n % size; ++ return n + (r ? (size - r) : 0); ++} ++ ++/* ++ * The device-mapper can be driven through one of two interfaces; ++ * ioctl or filesystem, depending which patch you have applied. ++ */ ++int 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); ++ ++#endif +diff -ruN linux-2.4.20/drivers/md/kcopyd.c linux/drivers/md/kcopyd.c +--- linux-2.4.20/drivers/md/kcopyd.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/kcopyd.c Wed Mar 26 12:54:17 2003 +@@ -0,0 +1,839 @@ ++/* ++ * Copyright (C) 2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include "kcopyd.h" ++ ++/* FIXME: this is only needed for the DMERR macros */ ++#include "dm.h" ++ ++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--) { ++ UnlockPage(_pages_array[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, 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(); ++} ++ ++/*----------------------------------------------------------------- ++ * 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_NOIO); ++ 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_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; ++ atomic_set(&bh->b_count, 1); ++ ++ bh->b_state = ((1 << BH_Uptodate) | (1 << BH_Mapped) | ++ (1 << BH_Lock) | (1 << BH_Req)); ++ ++ 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't 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_NOIO); ++} ++ ++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) { ++ if (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; ++ ++ /* ++ * 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; ++ 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; ++ 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-2.4.20/drivers/md/kcopyd.h linux/drivers/md/kcopyd.h +--- linux-2.4.20/drivers/md/kcopyd.h Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/kcopyd.h Wed Mar 26 14:14:34 2003 +@@ -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 ++#include ++ ++struct kcopyd_region { ++ kdev_t dev; ++ sector_t sector; ++ sector_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. ++ */ ++ sector_t offset; ++ sector_t block_size; ++ sector_t block_shift; ++ sector_t bpp_shift; /* blocks per page */ ++ sector_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 +diff -ruN linux-2.4.20/include/linux/device-mapper.h linux/include/linux/device-mapper.h +--- linux-2.4.20/include/linux/device-mapper.h Thu Jan 1 01:00:00 1970 ++++ linux/include/linux/device-mapper.h Wed Mar 26 14:14:55 2003 +@@ -0,0 +1,94 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the LGPL. ++ */ ++ ++#ifndef _LINUX_DEVICE_MAPPER_H ++#define _LINUX_DEVICE_MAPPER_H ++ ++typedef unsigned long sector_t; ++ ++struct dm_target; ++struct dm_table; ++struct dm_dev; ++ ++typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; ++ ++/* ++ * In the constructor the target parameter will already have the ++ * table, type, begin and len fields filled in. ++ */ ++typedef int (*dm_ctr_fn) (struct dm_target * target, int argc, char **argv); ++ ++/* ++ * The destructor doesn't need to free the dm_target, just ++ * anything hidden ti->private. ++ */ ++typedef void (*dm_dtr_fn) (struct dm_target * ti); ++ ++/* ++ * The map function must return: ++ * < 0: error ++ * = 0: The target will handle the io by resubmitting it later ++ * > 0: simple remap complete ++ */ ++typedef int (*dm_map_fn) (struct dm_target * ti, struct buffer_head * bh, ++ int rw, void **map_context); ++ ++/* ++ * Returns: ++ * < 0 : error (currently ignored) ++ * 0 : ended successfully ++ * 1 : for some reason the io has still not completed (eg, ++ * multipath target might want to requeue a failed io). ++ */ ++typedef int (*dm_endio_fn) (struct dm_target * ti, ++ struct buffer_head * bh, int rw, int error, ++ void *map_context); ++typedef int (*dm_status_fn) (struct dm_target * ti, status_type_t status_type, ++ char *result, int maxlen); ++ ++void dm_error(const char *message); ++ ++/* ++ * Constructors should call these functions to ensure destination devices ++ * are opened/closed correctly. ++ * FIXME: too many arguments. ++ */ ++int dm_get_device(struct dm_target *ti, const char *path, sector_t start, ++ sector_t len, int mode, struct dm_dev **result); ++void dm_put_device(struct dm_target *ti, 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_endio_fn end_io; ++ dm_status_fn status; ++}; ++ ++struct dm_target { ++ struct dm_table *table; ++ struct target_type *type; ++ ++ /* target limits */ ++ sector_t begin; ++ sector_t len; ++ ++ /* target specific data */ ++ void *private; ++ ++ /* Used to provide an error string from the ctr */ ++ char *error; ++}; ++ ++int dm_register_target(struct target_type *t); ++int dm_unregister_target(struct target_type *t); ++ ++#endif /* _LINUX_DEVICE_MAPPER_H */ +diff -ruN linux-2.4.20/include/linux/dm-ioctl.h linux/include/linux/dm-ioctl.h +--- linux-2.4.20/include/linux/dm-ioctl.h Thu Jan 1 01:00:00 1970 ++++ linux/include/linux/dm-ioctl.h Wed Mar 26 13:30:30 2003 +@@ -0,0 +1,149 @@ ++/* ++ * 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 ++ ++#define DM_DIR "mapper" /* Slashes not supported */ ++#define DM_MAX_TYPE_NAME 16 ++#define DM_NAME_LEN 128 ++#define DM_UUID_LEN 129 ++ ++/* ++ * 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 10 ++#define DM_VERSION_EXTRA "-ioctl (2003-03-26)" ++ ++/* 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 --git a/patches/common/linux-2.4.20-makefile.patch b/patches/common/linux-2.4.20-makefile.patch new file mode 100644 index 0000000..8ce64a1 --- /dev/null +++ b/patches/common/linux-2.4.20-makefile.patch @@ -0,0 +1,30 @@ +diff -ruN linux-2.4.20/drivers/md/Makefile linux/drivers/md/Makefile +--- linux-2.4.20/drivers/md/Makefile Fri Jan 10 16:34:50 2003 ++++ linux/drivers/md/Makefile Wed Mar 26 12:53:19 2003 +@@ -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 $@ $(dm-mod-objs) diff --git a/patches/common/linux-2.4.20-mempool.patch b/patches/common/linux-2.4.20-mempool.patch new file mode 100644 index 0000000..7bbd29d --- /dev/null +++ b/patches/common/linux-2.4.20-mempool.patch @@ -0,0 +1,356 @@ +diff -ruN linux-2.4.20/include/linux/mempool.h linux/include/linux/mempool.h +--- linux-2.4.20/include/linux/mempool.h Thu Jan 1 01:00:00 1970 ++++ linux/include/linux/mempool.h Wed Mar 26 12:53:48 2003 +@@ -0,0 +1,31 @@ ++/* ++ * memory buffer pool support ++ */ ++#ifndef _LINUX_MEMPOOL_H ++#define _LINUX_MEMPOOL_H ++ ++#include ++#include ++ ++struct mempool_s; ++typedef struct mempool_s mempool_t; ++ ++typedef void * (mempool_alloc_t)(int gfp_mask, void *pool_data); ++typedef void (mempool_free_t)(void *element, void *pool_data); ++ ++extern mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn, ++ mempool_free_t *free_fn, void *pool_data); ++extern int mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask); ++extern void mempool_destroy(mempool_t *pool); ++extern void * mempool_alloc(mempool_t *pool, int gfp_mask); ++extern void mempool_free(void *element, mempool_t *pool); ++ ++/* ++ * A mempool_alloc_t and mempool_free_t that get the memory from ++ * a slab that is passed in through pool_data. ++ */ ++void *mempool_alloc_slab(int gfp_mask, void *pool_data); ++void mempool_free_slab(void *element, void *pool_data); ++ ++ ++#endif /* _LINUX_MEMPOOL_H */ +diff -ruN linux-2.4.20/mm/Makefile linux/mm/Makefile +--- linux-2.4.20/mm/Makefile Fri Jan 10 16:36:02 2003 ++++ linux/mm/Makefile Wed Mar 26 12:53:19 2003 +@@ -9,12 +9,12 @@ + + O_TARGET := mm.o + +-export-objs := shmem.o filemap.o memory.o page_alloc.o ++export-objs := shmem.o filemap.o memory.o page_alloc.o mempool.o + + obj-y := memory.o mmap.o filemap.o mprotect.o mlock.o mremap.o \ + vmalloc.o slab.o bootmem.o swap.o vmscan.o page_io.o \ + page_alloc.o swap_state.o swapfile.o numa.o oom_kill.o \ +- shmem.o ++ shmem.o mempool.o + + obj-$(CONFIG_HIGHMEM) += highmem.o + +diff -ruN linux-2.4.20/mm/mempool.c linux/mm/mempool.c +--- linux-2.4.20/mm/mempool.c Thu Jan 1 01:00:00 1970 ++++ linux/mm/mempool.c Wed Mar 26 12:53:48 2003 +@@ -0,0 +1,299 @@ ++/* ++ * 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 ++#include ++#include ++#include ++ ++struct mempool_s { ++ spinlock_t lock; ++ int min_nr; /* nr of elements at *elements */ ++ int curr_nr; /* Current nr of elements at *elements */ ++ void **elements; ++ ++ void *pool_data; ++ mempool_alloc_t *alloc; ++ mempool_free_t *free; ++ wait_queue_head_t wait; ++}; ++ ++static void add_element(mempool_t *pool, void *element) ++{ ++ BUG_ON(pool->curr_nr >= pool->min_nr); ++ pool->elements[pool->curr_nr++] = element; ++} ++ ++static void *remove_element(mempool_t *pool) ++{ ++ BUG_ON(pool->curr_nr <= 0); ++ return pool->elements[--pool->curr_nr]; ++} ++ ++static void free_pool(mempool_t *pool) ++{ ++ while (pool->curr_nr) { ++ void *element = remove_element(pool); ++ pool->free(element, pool->pool_data); ++ } ++ kfree(pool->elements); ++ kfree(pool); ++} ++ ++/** ++ * 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. ++ */ ++mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn, ++ mempool_free_t *free_fn, void *pool_data) ++{ ++ mempool_t *pool; ++ ++ pool = kmalloc(sizeof(*pool), GFP_KERNEL); ++ if (!pool) ++ return NULL; ++ memset(pool, 0, sizeof(*pool)); ++ pool->elements = kmalloc(min_nr * sizeof(void *), GFP_KERNEL); ++ if (!pool->elements) { ++ kfree(pool); ++ return NULL; ++ } ++ spin_lock_init(&pool->lock); ++ pool->min_nr = min_nr; ++ pool->pool_data = pool_data; ++ init_waitqueue_head(&pool->wait); ++ pool->alloc = alloc_fn; ++ pool->free = free_fn; ++ ++ /* ++ * First pre-allocate the guaranteed number of buffers. ++ */ ++ while (pool->curr_nr < pool->min_nr) { ++ void *element; ++ ++ element = pool->alloc(GFP_KERNEL, pool->pool_data); ++ if (unlikely(!element)) { ++ free_pool(pool); ++ return NULL; ++ } ++ add_element(pool, element); ++ } ++ 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. ++ */ ++int mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask) ++{ ++ void *element; ++ void **new_elements; ++ unsigned long flags; ++ ++ BUG_ON(new_min_nr <= 0); ++ ++ spin_lock_irqsave(&pool->lock, flags); ++ if (new_min_nr < pool->min_nr) { ++ while (pool->curr_nr > new_min_nr) { ++ element = remove_element(pool); ++ spin_unlock_irqrestore(&pool->lock, flags); ++ pool->free(element, pool->pool_data); ++ spin_lock_irqsave(&pool->lock, flags); ++ } ++ pool->min_nr = new_min_nr; ++ goto out_unlock; ++ } ++ spin_unlock_irqrestore(&pool->lock, flags); ++ ++ /* Grow the pool */ ++ new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask); ++ if (!new_elements) ++ return -ENOMEM; ++ ++ spin_lock_irqsave(&pool->lock, flags); ++ memcpy(new_elements, pool->elements, ++ pool->curr_nr * sizeof(*new_elements)); ++ kfree(pool->elements); ++ pool->elements = new_elements; ++ pool->min_nr = new_min_nr; ++ ++ while (pool->curr_nr < pool->min_nr) { ++ spin_unlock_irqrestore(&pool->lock, flags); ++ element = pool->alloc(gfp_mask, pool->pool_data); ++ if (!element) ++ goto out; ++ spin_lock_irqsave(&pool->lock, flags); ++ if (pool->curr_nr < pool->min_nr) ++ add_element(pool, element); ++ else ++ kfree(element); /* Raced */ ++ } ++out_unlock: ++ spin_unlock_irqrestore(&pool->lock, flags); ++out: ++ return 0; ++} ++ ++/** ++ * 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 all elements have been returned to the pool (ie: ++ * freed) prior to calling mempool_destroy(). ++ */ ++void mempool_destroy(mempool_t *pool) ++{ ++ if (pool->curr_nr != pool->min_nr) ++ BUG(); /* There were outstanding elements */ ++ free_pool(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; ++ 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)) { ++ element = remove_element(pool); ++ 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) { ++ add_element(pool, element); ++ 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 --git a/patches/common/linux-2.4.20-vcalloc.patch b/patches/common/linux-2.4.20-vcalloc.patch new file mode 100644 index 0000000..f088450 --- /dev/null +++ b/patches/common/linux-2.4.20-vcalloc.patch @@ -0,0 +1,49 @@ +diff -ruN linux-2.4.20/mm/vmalloc.c linux/mm/vmalloc.c +--- linux-2.4.20/mm/vmalloc.c Fri Jan 10 16:36:03 2003 ++++ linux/mm/vmalloc.c Wed Mar 26 12:53:19 2003 +@@ -327,3 +327,22 @@ + 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 -ruN linux-2.4.20/include/linux/vmalloc.h linux/include/linux/vmalloc.h +--- linux-2.4.20/include/linux/vmalloc.h Fri Jan 10 16:35:58 2003 ++++ linux/include/linux/vmalloc.h Wed Mar 26 12:53:19 2003 +@@ -26,6 +26,7 @@ + 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 +diff -ruN linux-2.4.20/kernel/ksyms.c linux/kernel/ksyms.c +--- linux-2.4.20/kernel/ksyms.c Fri Jan 10 16:36:02 2003 ++++ linux/kernel/ksyms.c Wed Mar 26 12:53:19 2003 +@@ -111,6 +111,7 @@ + EXPORT_SYMBOL(vfree); + EXPORT_SYMBOL(__vmalloc); + EXPORT_SYMBOL(vmalloc_to_page); ++EXPORT_SYMBOL(vcalloc); + EXPORT_SYMBOL(mem_map); + EXPORT_SYMBOL(remap_page_range); + EXPORT_SYMBOL(max_mapnr); + diff --git a/patches/linux-2.4.20-VFS-lock.patch b/patches/linux-2.4.20-VFS-lock.patch new file mode 100644 index 0000000..33cffae --- /dev/null +++ b/patches/linux-2.4.20-VFS-lock.patch @@ -0,0 +1,243 @@ +diff -ruN linux-2.4.20/drivers/md/lvm.c linux/drivers/md/lvm.c +--- linux-2.4.20/drivers/md/lvm.c Fri Jan 10 16:34:50 2003 ++++ linux/drivers/md/lvm.c Wed Mar 26 15:36:34 2003 +@@ -229,9 +229,6 @@ + #define DEVICE_OFF(device) + #define LOCAL_END_REQUEST + +-/* lvm_do_lv_create calls fsync_dev_lockfs()/unlockfs() */ +-/* #define LVM_VFS_ENHANCEMENT */ +- + #include + #include + #include +@@ -2171,12 +2168,8 @@ + if (lv_ptr->lv_access & LV_SNAPSHOT) { + lv_t *org = lv_ptr->lv_snapshot_org, *last; + +- /* sync the original logical volume */ +- fsync_dev(org->lv_dev); +-#ifdef LVM_VFS_ENHANCEMENT + /* VFS function call to sync and lock the filesystem */ + fsync_dev_lockfs(org->lv_dev); +-#endif + + down_write(&org->lv_lock); + org->lv_access |= LV_SNAPSHOT_ORG; +@@ -2201,11 +2194,9 @@ + else + set_device_ro(lv_ptr->lv_dev, 1); + +-#ifdef LVM_VFS_ENHANCEMENT + /* VFS function call to unlock the filesystem */ + if (lv_ptr->lv_access & LV_SNAPSHOT) + unlockfs(lv_ptr->lv_snapshot_org->lv_dev); +-#endif + + lvm_gendisk.part[MINOR(lv_ptr->lv_dev)].de = + lvm_fs_create_lv(vg_ptr, lv_ptr); +diff -ruN linux-2.4.20/fs/buffer.c linux/fs/buffer.c +--- linux-2.4.20/fs/buffer.c Fri Jan 10 16:35:24 2003 ++++ linux/fs/buffer.c Wed Mar 26 15:36:34 2003 +@@ -361,6 +361,38 @@ + fsync_dev(dev); + } + ++int fsync_dev_lockfs(kdev_t dev) ++{ ++ /* you are not allowed to try locking all the filesystems ++ ** on the system, your chances of getting through without ++ ** total deadlock are slim to none. ++ */ ++ if (!dev) ++ return fsync_dev(dev) ; ++ ++ sync_buffers(dev, 0); ++ ++ lock_kernel(); ++ /* note, the FS might need to start transactions to ++ ** sync the inodes, or the quota, no locking until ++ ** after these are done ++ */ ++ sync_inodes(dev); ++#ifdef DQUOT_SYNC_DEV ++ DQUOT_SYNC_DEV(dev); ++#else ++ DQUOT_SYNC(dev); ++#endif ++ /* if inodes or quotas could be dirtied during the ++ ** sync_supers_lockfs call, the FS is responsible for getting ++ ** them on disk, without deadlocking against the lock ++ */ ++ sync_supers_lockfs(dev) ; ++ unlock_kernel(); ++ ++ return sync_buffers(dev, 1) ; ++} ++ + asmlinkage long sys_sync(void) + { + fsync_dev(0); +diff -ruN linux-2.4.20/fs/reiserfs/super.c linux/fs/reiserfs/super.c +--- linux-2.4.20/fs/reiserfs/super.c Fri Jan 10 16:35:32 2003 ++++ linux/fs/reiserfs/super.c Wed Mar 26 15:36:34 2003 +@@ -44,7 +44,7 @@ + reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); + journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s)); + reiserfs_block_writes(&th) ; +- journal_end(&th, s, 1) ; ++ journal_end_sync(&th, s, 1) ; + } + s->s_dirt = dirty; + unlock_kernel() ; +diff -ruN linux-2.4.20/fs/super.c linux/fs/super.c +--- linux-2.4.20/fs/super.c Fri Jan 10 16:35:25 2003 ++++ linux/fs/super.c Wed Mar 26 15:36:34 2003 +@@ -37,6 +37,13 @@ + LIST_HEAD(super_blocks); + spinlock_t sb_lock = SPIN_LOCK_UNLOCKED; + ++/* ++ * lock/unlockfs grab a read lock on s_umount, but you need this lock to ++ * make sure no lockfs runs are in progress before inserting/removing ++ * supers from the list. ++ */ ++static DECLARE_MUTEX(lockfs_sem); ++ + /* + * Handling of filesystem drivers list. + * Rules: +@@ -431,6 +438,19 @@ + put_super(sb); + } + ++static void write_super_lockfs(struct super_block *sb) ++{ ++ lock_super(sb); ++ if (sb->s_root && sb->s_op) { ++ if (sb->s_dirt && sb->s_op->write_super) ++ sb->s_op->write_super(sb); ++ if (sb->s_op->write_super_lockfs) { ++ sb->s_op->write_super_lockfs(sb); ++ } ++ } ++ unlock_super(sb); ++} ++ + static inline void write_super(struct super_block *sb) + { + lock_super(sb); +@@ -474,6 +494,39 @@ + spin_unlock(&sb_lock); + } + ++/* ++ * Note: don't check the dirty flag before waiting, we want the lock ++ * to happen every time this is called. dev must be non-zero ++ */ ++void sync_supers_lockfs(kdev_t dev) ++{ ++ struct super_block * sb; ++ ++ down(&lockfs_sem) ; ++ if (dev) { ++ sb = get_super(dev); ++ if (sb) { ++ write_super_lockfs(sb); ++ drop_super(sb); ++ } ++ } ++} ++ ++void unlockfs(kdev_t dev) ++{ ++ struct super_block * sb; ++ ++ if (dev) { ++ sb = get_super(dev); ++ if (sb) { ++ if (sb->s_op && sb->s_op->unlockfs) ++ sb->s_op->unlockfs(sb) ; ++ drop_super(sb); ++ } ++ } ++ up(&lockfs_sem) ; ++} ++ + /** + * get_super - get the superblock of a device + * @dev: device to get the superblock for +@@ -693,6 +746,7 @@ + goto out1; + + error = -EBUSY; ++ down(&lockfs_sem); + restart: + spin_lock(&sb_lock); + +@@ -704,6 +758,7 @@ + ((flags ^ old->s_flags) & MS_RDONLY)) { + spin_unlock(&sb_lock); + destroy_super(s); ++ up(&lockfs_sem); + goto out1; + } + if (!grab_super(old)) +@@ -711,12 +766,14 @@ + destroy_super(s); + blkdev_put(bdev, BDEV_FS); + path_release(&nd); ++ up(&lockfs_sem); + return old; + } + s->s_dev = dev; + s->s_bdev = bdev; + s->s_flags = flags; + insert_super(s, fs_type); ++ up(&lockfs_sem); + if (!fs_type->read_super(s, data, flags & MS_VERBOSE ? 1 : 0)) + goto Einval; + s->s_flags |= MS_ACTIVE; +@@ -824,7 +881,10 @@ + if (!deactivate_super(sb)) + return; + ++ down(&lockfs_sem); + down_write(&sb->s_umount); ++ up(&lockfs_sem); ++ + sb->s_root = NULL; + /* Need to clean after the sucker */ + if (fs->fs_flags & FS_LITTER) +diff -ruN linux-2.4.20/include/linux/fs.h linux/include/linux/fs.h +--- linux-2.4.20/include/linux/fs.h Fri Jan 10 16:35:55 2003 ++++ linux/include/linux/fs.h Wed Mar 26 15:36:34 2003 +@@ -1225,6 +1225,7 @@ + extern int sync_buffers(kdev_t, int); + extern void sync_dev(kdev_t); + extern int fsync_dev(kdev_t); ++extern int fsync_dev_lockfs(kdev_t); + extern int fsync_super(struct super_block *); + extern int fsync_no_super(kdev_t); + extern void sync_inodes_sb(struct super_block *); +@@ -1241,6 +1242,8 @@ + extern int filemap_fdatasync(struct address_space *); + extern int filemap_fdatawait(struct address_space *); + extern void sync_supers(kdev_t); ++extern void sync_supers_lockfs(kdev_t); ++extern void unlockfs(kdev_t); + extern int bmap(struct inode *, int); + extern int notify_change(struct dentry *, struct iattr *); + extern int permission(struct inode *, int); +diff -ruN linux-2.4.20/kernel/ksyms.c linux/kernel/ksyms.c +--- linux-2.4.20/kernel/ksyms.c Fri Jan 10 16:36:02 2003 ++++ linux/kernel/ksyms.c Wed Mar 26 15:36:34 2003 +@@ -184,6 +184,8 @@ + EXPORT_SYMBOL(invalidate_inode_pages); + EXPORT_SYMBOL(truncate_inode_pages); + EXPORT_SYMBOL(fsync_dev); ++EXPORT_SYMBOL(fsync_dev_lockfs); ++EXPORT_SYMBOL(unlockfs); + EXPORT_SYMBOL(fsync_no_super); + EXPORT_SYMBOL(permission); + EXPORT_SYMBOL(vfs_permission); diff --git a/patches/linux-2.4.20-devmapper-ioctl.patch b/patches/linux-2.4.20-devmapper-ioctl.patch new file mode 100644 index 0000000..523b8ba --- /dev/null +++ b/patches/linux-2.4.20-devmapper-ioctl.patch @@ -0,0 +1,7546 @@ +diff -ruN linux-2.4.20/Documentation/Configure.help linux/Documentation/Configure.help +--- linux-2.4.20/Documentation/Configure.help Fri Jan 10 16:33:55 2003 ++++ linux/Documentation/Configure.help Wed Mar 26 12:53:19 2003 +@@ -1822,6 +1822,20 @@ + want), say M here and read . The + module will be called lvm-mod.o. + ++Device-mapper support ++CONFIG_BLK_DEV_DM ++ Device-mapper is a low level volume manager. It works by allowing ++ people to specify mappings for ranges of logical sectors. Various ++ mapping types are available, in addition people may write their own ++ modules containing custom mappings if they wish. ++ ++ Higher level volume managers such as LVM2 use this driver. ++ ++ If you want to compile this as a module, say M here and read ++ . 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-2.4.20/MAINTAINERS linux/MAINTAINERS +--- linux-2.4.20/MAINTAINERS Fri Jan 10 16:33:49 2003 ++++ linux/MAINTAINERS Wed Mar 26 12:53:19 2003 +@@ -439,6 +439,13 @@ + W: http://www.debian.org/~dz/i8k/ + S: Maintained + ++DEVICE MAPPER ++P: Joe Thornber ++M: dm@uk.sistina.com ++L: linux-LVM@sistina.com ++W: http://www.sistina.com/lvm ++S: Maintained ++ + DEVICE NUMBER REGISTRY + P: H. Peter Anvin + M: hpa@zytor.com +diff -ruN linux-2.4.20/arch/mips64/kernel/ioctl32.c linux/arch/mips64/kernel/ioctl32.c +--- linux-2.4.20/arch/mips64/kernel/ioctl32.c Fri Jan 10 16:34:18 2003 ++++ linux/arch/mips64/kernel/ioctl32.c Wed Mar 26 13:37:24 2003 +@@ -33,6 +33,7 @@ + #include + #include + #include ++#include + + #include + #undef __KERNEL__ /* This file was born to be ugly ... */ +@@ -914,6 +915,20 @@ + IOCTL32_DEFAULT(STOP_ARRAY_RO), + IOCTL32_DEFAULT(RESTART_ARRAY_RW), + #endif /* CONFIG_MD */ ++ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++ IOCTL32_DEFAULT(DM_VERSION), ++ IOCTL32_DEFAULT(DM_REMOVE_ALL), ++ IOCTL32_DEFAULT(DM_DEV_CREATE), ++ IOCTL32_DEFAULT(DM_DEV_REMOVE), ++ IOCTL32_DEFAULT(DM_DEV_RELOAD), ++ IOCTL32_DEFAULT(DM_DEV_SUSPEND), ++ IOCTL32_DEFAULT(DM_DEV_RENAME), ++ IOCTL32_DEFAULT(DM_DEV_DEPS), ++ IOCTL32_DEFAULT(DM_DEV_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_WAIT), ++#endif /* CONFIG_BLK_DEV_DM */ + + IOCTL32_DEFAULT(MTIOCTOP), /* mtio.h ioctls */ + IOCTL32_HANDLER(MTIOCGET32, mt_ioctl_trans), +diff -ruN linux-2.4.20/arch/parisc/kernel/ioctl32.c linux/arch/parisc/kernel/ioctl32.c +--- linux-2.4.20/arch/parisc/kernel/ioctl32.c Fri Jan 10 16:34:19 2003 ++++ linux/arch/parisc/kernel/ioctl32.c Wed Mar 26 14:28:37 2003 +@@ -55,6 +55,7 @@ + #define max max */ + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -3415,6 +3416,20 @@ + COMPATIBLE_IOCTL(LV_BMAP) + COMPATIBLE_IOCTL(LV_SNAPSHOT_USE_RATE) + #endif /* LVM */ ++/* Device-Mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION) ++COMPATIBLE_IOCTL(DM_REMOVE_ALL) ++COMPATIBLE_IOCTL(DM_DEV_CREATE) ++COMPATIBLE_IOCTL(DM_DEV_REMOVE) ++COMPATIBLE_IOCTL(DM_DEV_RELOAD) ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND) ++COMPATIBLE_IOCTL(DM_DEV_RENAME) ++COMPATIBLE_IOCTL(DM_DEV_DEPS) ++COMPATIBLE_IOCTL(DM_DEV_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_WAIT) ++#endif /* CONFIG_BLK_DEV_DM */ + #if defined(CONFIG_DRM) || defined(CONFIG_DRM_MODULE) + COMPATIBLE_IOCTL(DRM_IOCTL_GET_MAGIC) + COMPATIBLE_IOCTL(DRM_IOCTL_IRQ_BUSID) +diff -ruN linux-2.4.20/arch/ppc64/kernel/ioctl32.c linux/arch/ppc64/kernel/ioctl32.c +--- linux-2.4.20/arch/ppc64/kernel/ioctl32.c Fri Jan 10 16:34:24 2003 ++++ linux/arch/ppc64/kernel/ioctl32.c Wed Mar 26 14:31:43 2003 +@@ -66,6 +66,7 @@ + #if defined(CONFIG_BLK_DEV_LVM) || defined(CONFIG_BLK_DEV_LVM_MODULE) + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -4362,6 +4363,20 @@ + COMPATIBLE_IOCTL(NBD_PRINT_DEBUG), + COMPATIBLE_IOCTL(NBD_SET_SIZE_BLOCKS), + COMPATIBLE_IOCTL(NBD_DISCONNECT), ++/* device-mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION), ++COMPATIBLE_IOCTL(DM_REMOVE_ALL), ++COMPATIBLE_IOCTL(DM_DEV_CREATE), ++COMPATIBLE_IOCTL(DM_DEV_REMOVE), ++COMPATIBLE_IOCTL(DM_DEV_RELOAD), ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND), ++COMPATIBLE_IOCTL(DM_DEV_RENAME), ++COMPATIBLE_IOCTL(DM_DEV_DEPS), ++COMPATIBLE_IOCTL(DM_DEV_STATUS), ++COMPATIBLE_IOCTL(DM_TARGET_STATUS), ++COMPATIBLE_IOCTL(DM_TARGET_WAIT), ++#endif /* CONFIG_BLK_DEV_DM */ + /* Remove *PRIVATE in 2.5 */ + COMPATIBLE_IOCTL(SIOCDEVPRIVATE), + COMPATIBLE_IOCTL(SIOCDEVPRIVATE+1), +diff -ruN linux-2.4.20/arch/s390x/kernel/ioctl32.c linux/arch/s390x/kernel/ioctl32.c +--- linux-2.4.20/arch/s390x/kernel/ioctl32.c Fri Jan 10 16:34:26 2003 ++++ linux/arch/s390x/kernel/ioctl32.c Wed Mar 26 13:36:43 2003 +@@ -25,6 +25,7 @@ + #include + #include + #include ++#include + #include + #include + #include +@@ -507,6 +508,18 @@ + IOCTL32_DEFAULT(VT_UNLOCKSWITCH), + + IOCTL32_DEFAULT(SIOCGSTAMP), ++ ++ IOCTL32_DEFAULT(DM_VERSION), ++ IOCTL32_DEFAULT(DM_REMOVE_ALL), ++ IOCTL32_DEFAULT(DM_DEV_CREATE), ++ IOCTL32_DEFAULT(DM_DEV_REMOVE), ++ IOCTL32_DEFAULT(DM_DEV_RELOAD), ++ IOCTL32_DEFAULT(DM_DEV_SUSPEND), ++ IOCTL32_DEFAULT(DM_DEV_RENAME), ++ IOCTL32_DEFAULT(DM_DEV_DEPS), ++ IOCTL32_DEFAULT(DM_DEV_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_STATUS), ++ IOCTL32_DEFAULT(DM_TARGET_WAIT), + + IOCTL32_HANDLER(SIOCGIFNAME, dev_ifname32), + IOCTL32_HANDLER(SIOCGIFCONF, dev_ifconf), +diff -ruN linux-2.4.20/arch/sparc64/kernel/ioctl32.c linux/arch/sparc64/kernel/ioctl32.c +--- linux-2.4.20/arch/sparc64/kernel/ioctl32.c Fri Jan 10 16:34:30 2003 ++++ linux/arch/sparc64/kernel/ioctl32.c Wed Mar 26 14:32:03 2003 +@@ -55,6 +55,7 @@ + #if defined(CONFIG_BLK_DEV_LVM) || defined(CONFIG_BLK_DEV_LVM_MODULE) + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -5023,6 +5024,21 @@ + COMPATIBLE_IOCTL(NBD_PRINT_DEBUG) + COMPATIBLE_IOCTL(NBD_SET_SIZE_BLOCKS) + COMPATIBLE_IOCTL(NBD_DISCONNECT) ++/* device-mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION) ++COMPATIBLE_IOCTL(DM_REMOVE_ALL) ++COMPATIBLE_IOCTL(DM_DEV_CREATE) ++COMPATIBLE_IOCTL(DM_DEV_REMOVE) ++COMPATIBLE_IOCTL(DM_DEV_RELOAD) ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND) ++COMPATIBLE_IOCTL(DM_DEV_RENAME) ++COMPATIBLE_IOCTL(DM_DEV_DEPS) ++COMPATIBLE_IOCTL(DM_DEV_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_WAIT) ++#endif /* CONFIG_BLK_DEV_DM */ ++ + /* And these ioctls need translation */ + HANDLE_IOCTL(MEMREADOOB32, mtd_rw_oob) + HANDLE_IOCTL(MEMWRITEOOB32, mtd_rw_oob) +diff -ruN linux-2.4.20/arch/x86_64/ia32/ia32_ioctl.c linux/arch/x86_64/ia32/ia32_ioctl.c +--- linux-2.4.20/arch/x86_64/ia32/ia32_ioctl.c Fri Jan 10 16:34:32 2003 ++++ linux/arch/x86_64/ia32/ia32_ioctl.c Wed Mar 26 14:29:31 2003 +@@ -62,6 +62,7 @@ + #define max max + #include + #endif /* LVM */ ++#include + + #include + /* Ugly hack. */ +@@ -3776,6 +3777,20 @@ + COMPATIBLE_IOCTL(LV_BMAP) + COMPATIBLE_IOCTL(LV_SNAPSHOT_USE_RATE) + #endif /* LVM */ ++/* Device-Mapper */ ++#if defined(CONFIG_BLK_DEV_DM) || defined(CONFIG_BLK_DEV_DM_MODULE) ++COMPATIBLE_IOCTL(DM_VERSION) ++COMPATIBLE_IOCTL(DM_REMOVE_ALL) ++COMPATIBLE_IOCTL(DM_DEV_CREATE) ++COMPATIBLE_IOCTL(DM_DEV_REMOVE) ++COMPATIBLE_IOCTL(DM_DEV_RELOAD) ++COMPATIBLE_IOCTL(DM_DEV_SUSPEND) ++COMPATIBLE_IOCTL(DM_DEV_RENAME) ++COMPATIBLE_IOCTL(DM_DEV_DEPS) ++COMPATIBLE_IOCTL(DM_DEV_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_STATUS) ++COMPATIBLE_IOCTL(DM_TARGET_WAIT) ++#endif /* CONFIG_BLK_DEV_DM */ + #if defined(CONFIG_DRM) || defined(CONFIG_DRM_MODULE) + COMPATIBLE_IOCTL(DRM_IOCTL_GET_MAGIC) + COMPATIBLE_IOCTL(DRM_IOCTL_IRQ_BUSID) +diff -ruN linux-2.4.20/drivers/md/Config.in linux/drivers/md/Config.in +--- linux-2.4.20/drivers/md/Config.in Fri Jan 10 16:34:50 2003 ++++ linux/drivers/md/Config.in Wed Mar 26 12:53:19 2003 +@@ -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 $CONFIG_MD ++fi + + endmenu +diff -ruN linux-2.4.20/drivers/md/Makefile linux/drivers/md/Makefile +--- linux-2.4.20/drivers/md/Makefile Fri Jan 10 16:34:50 2003 ++++ linux/drivers/md/Makefile Wed Mar 26 12:53:19 2003 +@@ -4,9 +4,12 @@ + + O_TARGET := mddev.o + +-export-objs := md.o xor.o ++export-objs := md.o xor.o dm-table.o dm-target.o kcopyd.o + list-multi := lvm-mod.o + lvm-mod-objs := lvm.o lvm-snap.o lvm-fs.o ++dm-mod-objs := dm.o dm-table.o dm-target.o dm-ioctl.o \ ++ dm-linear.o dm-stripe.o dm-snapshot.o dm-exception-store.o \ ++ kcopyd.o + + # Note: link order is important. All raid personalities + # and xor.o must come before md.o, as they each initialise +@@ -20,8 +23,12 @@ + obj-$(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-2.4.20/drivers/md/dm-exception-store.c linux/drivers/md/dm-exception-store.c +--- linux-2.4.20/drivers/md/dm-exception-store.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-exception-store.c Wed Mar 26 14:21:16 2003 +@@ -0,0 +1,704 @@ ++/* ++ * 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 ++#include ++#include ++#include ++ ++/*----------------------------------------------------------------- ++ * 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; ++} ++ ++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; ++ ++ 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; ++ sector_t size = get_dev_size(store->snap->cow->dev); ++ ++ /* Is there enough room ? */ ++ if (size < ((ps->next_free + 1) * 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) == 1) ++ 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->valid) { ++ DMWARN("snapshot is marked invalid"); ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ 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 { ++ sector_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; ++ sector_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) ++{ ++ 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-2.4.20/drivers/md/dm-ioctl.c linux/drivers/md/dm-ioctl.c +--- linux-2.4.20/drivers/md/dm-ioctl.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-ioctl.c Wed Mar 26 14:34:50 2003 +@@ -0,0 +1,1160 @@ ++/* ++ * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include ++ ++#define DM_DRIVER_EMAIL "dm@uk.sistina.com" ++ ++/*----------------------------------------------------------------- ++ * The ioctl interface needs to be able to look up devices by ++ * name or uuid. ++ *---------------------------------------------------------------*/ ++struct hash_cell { ++ struct list_head name_list; ++ struct list_head uuid_list; ++ ++ char *name; ++ char *uuid; ++ struct mapped_device *md; ++ ++ /* I hate devfs */ ++ devfs_handle_t devfs_entry; ++}; ++ ++#define NUM_BUCKETS 64 ++#define MASK_BUCKETS (NUM_BUCKETS - 1) ++static struct list_head _name_buckets[NUM_BUCKETS]; ++static struct list_head _uuid_buckets[NUM_BUCKETS]; ++ ++static devfs_handle_t _dev_dir; ++void dm_hash_remove_all(void); ++ ++/* ++ * Guards access to all three tables. ++ */ ++static DECLARE_RWSEM(_hash_lock); ++ ++static void init_buckets(struct list_head *buckets) ++{ ++ unsigned int i; ++ ++ for (i = 0; i < NUM_BUCKETS; i++) ++ INIT_LIST_HEAD(buckets + i); ++} ++ ++int dm_hash_init(void) ++{ ++ init_buckets(_name_buckets); ++ init_buckets(_uuid_buckets); ++ _dev_dir = devfs_mk_dir(0, DM_DIR, NULL); ++ return 0; ++} ++ ++void dm_hash_exit(void) ++{ ++ dm_hash_remove_all(); ++ devfs_unregister(_dev_dir); ++} ++ ++/*----------------------------------------------------------------- ++ * Hash function: ++ * We're not really concerned with the str hash function being ++ * fast since it's only used by the ioctl interface. ++ *---------------------------------------------------------------*/ ++static unsigned int hash_str(const char *str) ++{ ++ const unsigned int hash_mult = 2654435387U; ++ unsigned int h = 0; ++ ++ while (*str) ++ h = (h + (unsigned int) *str++) * hash_mult; ++ ++ return h & MASK_BUCKETS; ++} ++ ++/*----------------------------------------------------------------- ++ * Code for looking up a device by name ++ *---------------------------------------------------------------*/ ++static struct hash_cell *__get_name_cell(const char *str) ++{ ++ struct list_head *tmp; ++ struct hash_cell *hc; ++ unsigned int h = hash_str(str); ++ ++ list_for_each(tmp, _name_buckets + h) { ++ hc = list_entry(tmp, struct hash_cell, name_list); ++ if (!strcmp(hc->name, str)) ++ return hc; ++ } ++ ++ return NULL; ++} ++ ++static struct hash_cell *__get_uuid_cell(const char *str) ++{ ++ struct list_head *tmp; ++ struct hash_cell *hc; ++ unsigned int h = hash_str(str); ++ ++ list_for_each(tmp, _uuid_buckets + h) { ++ hc = list_entry(tmp, struct hash_cell, uuid_list); ++ if (!strcmp(hc->uuid, str)) ++ return hc; ++ } ++ ++ return NULL; ++} ++ ++/*----------------------------------------------------------------- ++ * Inserting, removing and renaming a device. ++ *---------------------------------------------------------------*/ ++static inline char *kstrdup(const char *str) ++{ ++ char *r = kmalloc(strlen(str) + 1, GFP_KERNEL); ++ if (r) ++ strcpy(r, str); ++ return r; ++} ++ ++static struct hash_cell *alloc_cell(const char *name, const char *uuid, ++ struct mapped_device *md) ++{ ++ struct hash_cell *hc; ++ ++ hc = kmalloc(sizeof(*hc), GFP_KERNEL); ++ if (!hc) ++ return NULL; ++ ++ hc->name = kstrdup(name); ++ if (!hc->name) { ++ kfree(hc); ++ return NULL; ++ } ++ ++ if (!uuid) ++ hc->uuid = NULL; ++ ++ else { ++ hc->uuid = kstrdup(uuid); ++ if (!hc->uuid) { ++ kfree(hc->name); ++ kfree(hc); ++ return NULL; ++ } ++ } ++ ++ INIT_LIST_HEAD(&hc->name_list); ++ INIT_LIST_HEAD(&hc->uuid_list); ++ hc->md = md; ++ return hc; ++} ++ ++static void free_cell(struct hash_cell *hc) ++{ ++ if (hc) { ++ kfree(hc->name); ++ kfree(hc->uuid); ++ kfree(hc); ++ } ++} ++ ++/* ++ * devfs stuff. ++ */ ++static int register_with_devfs(struct hash_cell *hc) ++{ ++ kdev_t dev = dm_kdev(hc->md); ++ ++ hc->devfs_entry = ++ devfs_register(_dev_dir, hc->name, DEVFS_FL_CURRENT_OWNER, ++ major(dev), minor(dev), ++ S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP, ++ &dm_blk_dops, NULL); ++ ++ return 0; ++} ++ ++static int unregister_with_devfs(struct hash_cell *hc) ++{ ++ devfs_unregister(hc->devfs_entry); ++ return 0; ++} ++ ++/* ++ * The kdev_t and uuid of a device can never change once it is ++ * initially inserted. ++ */ ++int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) ++{ ++ struct hash_cell *cell; ++ ++ /* ++ * Allocate the new cells. ++ */ ++ cell = alloc_cell(name, uuid, md); ++ if (!cell) ++ return -ENOMEM; ++ ++ /* ++ * Insert the cell into all three hash tables. ++ */ ++ down_write(&_hash_lock); ++ if (__get_name_cell(name)) ++ goto bad; ++ ++ list_add(&cell->name_list, _name_buckets + hash_str(name)); ++ ++ if (uuid) { ++ if (__get_uuid_cell(uuid)) { ++ list_del(&cell->name_list); ++ goto bad; ++ } ++ list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); ++ } ++ register_with_devfs(cell); ++ dm_get(md); ++ up_write(&_hash_lock); ++ ++ return 0; ++ ++ bad: ++ up_write(&_hash_lock); ++ free_cell(cell); ++ return -EBUSY; ++} ++ ++void __hash_remove(struct hash_cell *hc) ++{ ++ /* remove from the dev hash */ ++ list_del(&hc->uuid_list); ++ list_del(&hc->name_list); ++ unregister_with_devfs(hc); ++ dm_put(hc->md); ++} ++ ++void dm_hash_remove_all(void) ++{ ++ int i; ++ struct hash_cell *hc; ++ struct list_head *tmp, *n; ++ ++ down_write(&_hash_lock); ++ for (i = 0; i < NUM_BUCKETS; i++) { ++ list_for_each_safe(tmp, n, _name_buckets + i) { ++ hc = list_entry(tmp, struct hash_cell, name_list); ++ __hash_remove(hc); ++ } ++ } ++ up_write(&_hash_lock); ++} ++ ++int dm_hash_rename(const char *old, const char *new) ++{ ++ char *new_name, *old_name; ++ struct hash_cell *hc; ++ ++ /* ++ * duplicate new. ++ */ ++ new_name = kstrdup(new); ++ if (!new_name) ++ return -ENOMEM; ++ ++ down_write(&_hash_lock); ++ ++ /* ++ * Is new free ? ++ */ ++ hc = __get_name_cell(new); ++ if (hc) { ++ DMWARN("asked to rename to an already existing name %s -> %s", ++ old, new); ++ up_write(&_hash_lock); ++ return -EBUSY; ++ } ++ ++ /* ++ * Is there such a device as 'old' ? ++ */ ++ hc = __get_name_cell(old); ++ if (!hc) { ++ DMWARN("asked to rename a non existent device %s -> %s", ++ old, new); ++ up_write(&_hash_lock); ++ return -ENXIO; ++ } ++ ++ /* ++ * rename and move the name cell. ++ */ ++ list_del(&hc->name_list); ++ old_name = hc->name; ++ hc->name = new_name; ++ list_add(&hc->name_list, _name_buckets + hash_str(new_name)); ++ ++ /* rename the device node in devfs */ ++ unregister_with_devfs(hc); ++ register_with_devfs(hc); ++ ++ up_write(&_hash_lock); ++ kfree(old_name); ++ return 0; ++} ++ ++ ++/*----------------------------------------------------------------- ++ * 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); ++ ++/* ++ * 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); ++} ++ ++static int populate_table(struct dm_table *table, struct dm_ioctl *args) ++{ ++ int i = 0, r, first = 1; ++ struct dm_target_spec *spec; ++ char *params; ++ void *begin, *end; ++ ++ if (!args->target_count) { ++ DMWARN("populate_table: no targets specified"); ++ return -EINVAL; ++ } ++ ++ begin = (void *) args; ++ end = begin + args->data_size; ++ ++ 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) { ++ DMWARN("unable to find target"); ++ return -EINVAL; ++ } ++ ++ r = dm_table_add_target(table, spec->target_type, ++ spec->sector_start, spec->length, ++ params); ++ if (r) { ++ DMWARN("error adding target to table"); ++ return -EINVAL; ++ } ++ ++ first = 0; ++ } ++ ++ return dm_table_complete(table); ++} ++ ++/* ++ * 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 int __info(struct mapped_device *md, struct dm_ioctl *param) ++{ ++ kdev_t dev = dm_kdev(md); ++ struct dm_table *table; ++ struct block_device *bdev; ++ ++ param->flags = DM_EXISTS_FLAG; ++ if (dm_suspended(md)) ++ param->flags |= DM_SUSPEND_FLAG; ++ ++ param->dev = kdev_t_to_nr(dev); ++ bdev = bdget(param->dev); ++ if (!bdev) ++ return -ENXIO; ++ ++ param->open_count = bdev->bd_openers; ++ bdput(bdev); ++ ++ if (is_read_only(dev)) ++ param->flags |= DM_READONLY_FLAG; ++ ++ table = dm_get_table(md); ++ param->target_count = dm_table_get_num_targets(table); ++ dm_table_put(table); ++ ++ return 0; ++} ++ ++/* ++ * Always use UUID for lookups if it's present, otherwise use name. ++ */ ++static inline struct mapped_device *find_device(struct dm_ioctl *param) ++{ ++ struct hash_cell *hc; ++ struct mapped_device *md = NULL; ++ ++ down_read(&_hash_lock); ++ hc = *param->uuid ? __get_uuid_cell(param->uuid) : ++ __get_name_cell(param->name); ++ if (hc) { ++ md = hc->md; ++ ++ /* ++ * Sneakily write in both the name and the uuid ++ * while we have the cell. ++ */ ++ strncpy(param->name, hc->name, sizeof(param->name)); ++ if (hc->uuid) ++ strncpy(param->uuid, hc->uuid, sizeof(param->uuid) - 1); ++ else ++ param->uuid[0] = '\0'; ++ ++ dm_get(md); ++ } ++ up_read(&_hash_lock); ++ ++ return md; ++} ++ ++#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 = find_device(param); ++ if (!md) ++ /* ++ * Device not found - returns cleared exists flag. ++ */ ++ goto out; ++ ++ __info(md, param); ++ dm_put(md); ++ ++ out: ++ 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 check_name(const char *name) ++{ ++ if (strchr(name, '/')) { ++ DMWARN("invalid device name"); ++ return -EINVAL; ++ } ++ ++ return 0; ++} ++ ++static int create(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ kdev_t dev; ++ struct dm_table *t; ++ struct mapped_device *md; ++ int minor; ++ ++ r = check_name(param->name); ++ if (r) ++ return r; ++ ++ r = dm_table_create(&t, get_mode(param)); ++ if (r) ++ return r; ++ ++ r = populate_table(t, param); ++ if (r) { ++ dm_table_put(t); ++ return r; ++ } ++ ++ minor = (param->flags & DM_PERSISTENT_DEV_FLAG) ? ++ minor(to_kdev_t(param->dev)) : -1; ++ ++ r = dm_create(minor, t, &md); ++ if (r) { ++ dm_table_put(t); ++ return r; ++ } ++ dm_table_put(t); /* md will have grabbed its own reference */ ++ ++ dev = dm_kdev(md); ++ set_device_ro(dev, (param->flags & DM_READONLY_FLAG)); ++ r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); ++ dm_put(md); ++ ++ return r ? r : info(param, user); ++} ++ ++/* ++ * 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, num_targets; ++ struct dm_target_spec *spec; ++ char *outptr; ++ status_type_t type; ++ struct dm_table *table = dm_get_table(md); ++ ++ if (param->flags & DM_STATUS_TABLE_FLAG) ++ type = STATUSTYPE_TABLE; ++ else ++ type = STATUSTYPE_INFO; ++ ++ outptr = outbuf; ++ ++ /* Get all the target info */ ++ num_targets = dm_table_get_num_targets(table); ++ for (i = 0; i < num_targets; i++) { ++ struct dm_target *ti = dm_table_get_target(table, i); ++ ++ if (outptr - outbuf + ++ sizeof(struct dm_target_spec) > param->data_size) { ++ dm_table_put(table); ++ return -ENOMEM; ++ } ++ ++ spec = (struct dm_target_spec *) outptr; ++ ++ spec->status = 0; ++ spec->sector_start = ti->begin; ++ spec->length = ti->len; ++ strncpy(spec->target_type, ti->type->name, ++ sizeof(spec->target_type)); ++ ++ outptr += sizeof(struct dm_target_spec); ++ ++ /* Get the status/table string from the target driver */ ++ if (ti->type->status) ++ ti->type->status(ti, type, outptr, ++ outbuf + param->data_size - outptr); ++ else ++ outptr[0] = '\0'; ++ ++ outptr += strlen(outptr) + 1; ++ _align(outptr, ALIGNMENT); ++ spec->next = outptr - outbuf; ++ } ++ ++ param->target_count = num_targets; ++ *len = outptr - outbuf; ++ dm_table_put(table); ++ ++ 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 = find_device(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(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; ++ struct dm_table *table; ++ DECLARE_WAITQUEUE(wq, current); ++ ++ md = find_device(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); ++ table = dm_get_table(md); ++ dm_table_add_wait_queue(table, &wq); ++ dm_table_put(table); ++ dm_put(md); ++ ++ yield(); ++ 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; ++ struct dm_table *table; ++ ++ md = find_device(param); ++ if (!md) ++ goto out; ++ table = dm_get_table(md); ++ ++ /* ++ * Setup the basic dm_ioctl structure. ++ */ ++ __info(md, param); ++ ++ /* ++ * Count the devices. ++ */ ++ count = 0; ++ list_for_each(tmp, dm_table_get_devices(table)) ++ count++; ++ ++ /* ++ * Allocate a kernel space version of the dm_target_status ++ * struct. ++ */ ++ if (array_too_big(sizeof(*deps), sizeof(*deps->dev), count)) { ++ dm_table_put(table); ++ dm_put(md); ++ return -ENOMEM; ++ } ++ ++ len = sizeof(*deps) + (sizeof(*deps->dev) * count); ++ deps = kmalloc(len, GFP_KERNEL); ++ if (!deps) { ++ dm_table_put(table); ++ dm_put(md); ++ return -ENOMEM; ++ } ++ ++ /* ++ * Fill in the devices. ++ */ ++ deps->count = count; ++ count = 0; ++ list_for_each(tmp, dm_table_get_devices(table)) { ++ struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); ++ deps->dev[count++] = dd->bdev->bd_dev; ++ } ++ dm_table_put(table); ++ dm_put(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) ++{ ++ struct hash_cell *hc; ++ ++ down_write(&_hash_lock); ++ hc = *param->uuid ? __get_uuid_cell(param->uuid) : ++ __get_name_cell(param->name); ++ if (!hc) { ++ DMWARN("device doesn't appear to be in the dev hash table."); ++ up_write(&_hash_lock); ++ return -EINVAL; ++ } ++ ++ /* ++ * You may ask the interface to drop its reference to an ++ * in use device. This is no different to unlinking a ++ * file that someone still has open. The device will not ++ * actually be destroyed until the last opener closes it. ++ * The name and uuid of the device (both are interface ++ * properties) will be available for reuse immediately. ++ * ++ * You don't want to drop a _suspended_ device from the ++ * interface, since that will leave you with no way of ++ * resuming it. ++ */ ++ if (dm_suspended(hc->md)) { ++ DMWARN("refusing to remove a suspended device."); ++ up_write(&_hash_lock); ++ return -EPERM; ++ } ++ ++ __hash_remove(hc); ++ up_write(&_hash_lock); ++ return 0; ++} ++ ++static int remove_all(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ dm_hash_remove_all(); ++ return 0; ++} ++ ++static int suspend(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ struct mapped_device *md; ++ ++ md = find_device(param); ++ if (!md) ++ return -ENXIO; ++ ++ if (param->flags & DM_SUSPEND_FLAG) ++ r = dm_suspend(md); ++ else ++ r = dm_resume(md); ++ ++ dm_put(md); ++ return r; ++} ++ ++static int reload(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ kdev_t dev; ++ struct mapped_device *md; ++ struct dm_table *t; ++ ++ r = dm_table_create(&t, get_mode(param)); ++ if (r) ++ return r; ++ ++ r = populate_table(t, param); ++ if (r) { ++ dm_table_put(t); ++ return r; ++ } ++ ++ md = find_device(param); ++ if (!md) { ++ dm_table_put(t); ++ return -ENXIO; ++ } ++ ++ r = dm_swap_table(md, t); ++ if (r) { ++ dm_put(md); ++ dm_table_put(t); ++ return r; ++ } ++ dm_table_put(t); /* md will have taken its own reference */ ++ ++ dev = dm_kdev(md); ++ set_device_ro(dev, (param->flags & DM_READONLY_FLAG)); ++ dm_put(md); ++ ++ r = info(param, user); ++ return r; ++} ++ ++static int rename(struct dm_ioctl *param, struct dm_ioctl *user) ++{ ++ int r; ++ char *new_name = (char *) param + param->data_start; ++ ++ if (valid_str(new_name, (void *) param, ++ (void *) param + param->data_size)) { ++ DMWARN("Invalid new logical volume name supplied."); ++ return -EINVAL; ++ } ++ ++ r = check_name(new_name); ++ if (r) ++ return r; ++ ++ return dm_hash_rename(param->name, new_name); ++} ++ ++ ++/*----------------------------------------------------------------- ++ * Implementation of open/close/ioctl on the special char ++ * device. ++ *---------------------------------------------------------------*/ ++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}, ++ }; ++ ++ return (cmd >= ARRAY_SIZE(_ioctls)) ? 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) ++{ ++ /* Ignores parameters */ ++ if (cmd == DM_REMOVE_ALL_CMD) ++ return 0; ++ ++ /* 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; ++ ++ /* only root can play with this */ ++ if (!capable(CAP_SYS_ADMIN)) ++ return -EACCES; ++ ++ 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 = { ++ .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 = dm_hash_init(); ++ if (r) ++ return r; ++ ++ r = misc_register(&_dm_misc); ++ if (r) { ++ DMERR("misc_register failed for control device"); ++ dm_hash_exit(); ++ return r; ++ } ++ ++ r = devfs_generate_path(_dm_misc.devfs_handle, rname + 3, ++ sizeof rname - 3); ++ if (r == -ENOSYS) ++ goto done; /* 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); ++ ++ done: ++ 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); ++ dm_hash_exit(); ++ return r; ++} ++ ++void dm_interface_exit(void) ++{ ++ if (misc_deregister(&_dm_misc) < 0) ++ DMERR("misc_deregister failed for control device"); ++ ++ dm_hash_exit(); ++} +diff -ruN linux-2.4.20/drivers/md/dm-linear.c linux/drivers/md/dm-linear.c +--- linux-2.4.20/drivers/md/dm-linear.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-linear.c Wed Mar 26 13:27:22 2003 +@@ -0,0 +1,121 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++ ++/* ++ * Linear: maps a linear range of a device. ++ */ ++struct linear_c { ++ struct dm_dev *dev; ++ sector_t start; ++}; ++ ++/* ++ * Construct a linear mapping: ++ */ ++static int linear_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ struct linear_c *lc; ++ ++ if (argc != 2) { ++ ti->error = "dm-linear: Not enough arguments"; ++ return -EINVAL; ++ } ++ ++ lc = kmalloc(sizeof(*lc), GFP_KERNEL); ++ if (lc == NULL) { ++ ti->error = "dm-linear: Cannot allocate linear context"; ++ return -ENOMEM; ++ } ++ ++ if (sscanf(argv[1], SECTOR_FORMAT, &lc->start) != 1) { ++ ti->error = "dm-linear: Invalid device sector"; ++ goto bad; ++ } ++ ++ if (dm_get_device(ti, argv[0], lc->start, ti->len, ++ dm_table_get_mode(ti->table), &lc->dev)) { ++ ti->error = "dm-linear: Device lookup failed"; ++ goto bad; ++ } ++ ++ ti->private = lc; ++ return 0; ++ ++ bad: ++ kfree(lc); ++ return -EINVAL; ++} ++ ++static void linear_dtr(struct dm_target *ti) ++{ ++ struct linear_c *lc = (struct linear_c *) ti->private; ++ ++ dm_put_device(ti, lc->dev); ++ kfree(lc); ++} ++ ++static int linear_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ struct linear_c *lc = (struct linear_c *) ti->private; ++ ++ bh->b_rdev = lc->dev->dev; ++ bh->b_rsector = lc->start + (bh->b_rsector - ti->begin); ++ ++ return 1; ++} ++ ++static int linear_status(struct dm_target *ti, status_type_t type, ++ char *result, int maxlen) ++{ ++ struct linear_c *lc = (struct linear_c *) ti->private; ++ ++ switch (type) { ++ case STATUSTYPE_INFO: ++ result[0] = '\0'; ++ break; ++ ++ case STATUSTYPE_TABLE: ++ snprintf(result, maxlen, "%s " SECTOR_FORMAT, ++ kdevname(to_kdev_t(lc->dev->bdev->bd_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-2.4.20/drivers/md/dm-snapshot.c linux/drivers/md/dm-snapshot.c +--- linux-2.4.20/drivers/md/dm-snapshot.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-snapshot.c Wed Mar 26 14:12:59 2003 +@@ -0,0 +1,1170 @@ ++/* ++ * dm-snapshot.c ++ * ++ * Copyright (C) 2001-2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#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 ++ ++/* ++ * 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) ++{ ++ sector_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; ++} ++ ++/* ++ * 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:

++ */ ++static int snapshot_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ struct dm_snapshot *s; ++ unsigned long chunk_size; ++ int r = -EINVAL; ++ char persistent; ++ char *origin_path; ++ char *cow_path; ++ char *value; ++ int blocksize; ++ ++ if (argc < 4) { ++ ti->error = "dm-snapshot: requires exactly 4 arguments"; ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ origin_path = argv[0]; ++ cow_path = argv[1]; ++ persistent = toupper(*argv[2]); ++ ++ if (persistent != 'P' && persistent != 'N') { ++ ti->error = "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) { ++ ti->error = "Invalid chunk size"; ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ s = kmalloc(sizeof(*s), GFP_KERNEL); ++ if (s == NULL) { ++ ti->error = "Cannot allocate snapshot context private " ++ "structure"; ++ r = -ENOMEM; ++ goto bad; ++ } ++ ++ r = dm_get_device(ti, origin_path, 0, ti->len, FMODE_READ, &s->origin); ++ if (r) { ++ ti->error = "Cannot get origin device"; ++ goto bad_free; ++ } ++ ++ /* FIXME: get cow length */ ++ r = dm_get_device(ti, cow_path, 0, 0, ++ FMODE_READ | FMODE_WRITE, &s->cow); ++ if (r) { ++ dm_put_device(ti, s->origin); ++ ti->error = "Cannot get COW device"; ++ goto bad_free; ++ } ++ ++ /* ++ * 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); ++ if (chunk_size % (blocksize / SECTOR_SIZE)) { ++ ti->error = "Chunk 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) { ++ ti->error = "Chunk size is too big"; ++ r = -EINVAL; ++ goto bad_putdev; ++ } ++ ++ /* Check chunk_size is a power of 2 */ ++ if (chunk_size & (chunk_size - 1)) { ++ ti->error = "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; ++ init_rwsem(&s->lock); ++ s->table = ti->table; ++ ++ /* Allocate hash table for COW data */ ++ if (init_hash_tables(s)) { ++ ti->error = "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 == 'P') ++ r = dm_create_persistent(&s->store, s->chunk_size); ++ else ++ r = dm_create_transient(&s->store, s, blocksize); ++ ++ if (r) { ++ ti->error = "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; ++ ti->error = "Cannot register snapshot origin"; ++ goto bad_free2; ++ } ++#if LVM_VFS_ENHANCEMENT ++ unlockfs(s->origin->dev); ++#endif ++ kcopyd_inc_client_count(); ++ ++ ti->private = s; ++ return 0; ++ ++ bad_free2: ++#if LVM_VFS_ENHANCEMENT ++ unlockfs(s->origin->dev); ++#endif ++ s->store.destroy(&s->store); ++ ++ bad_free1: ++ exit_exception_table(&s->pending, pending_cache); ++ exit_exception_table(&s->complete, exception_cache); ++ ++ bad_putdev: ++ dm_put_device(ti, s->cow); ++ dm_put_device(ti, s->origin); ++ ++ bad_free: ++ kfree(s); ++ ++ bad: ++ return r; ++} ++ ++static void snapshot_dtr(struct dm_target *ti) ++{ ++ struct dm_snapshot *s = (struct dm_snapshot *) ti->private; ++ ++ dm_table_event(ti->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_put_device(ti, s->origin); ++ dm_put_device(ti, 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 dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ struct exception *e; ++ struct dm_snapshot *s = (struct dm_snapshot *) ti->private; ++ 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(struct dm_target *ti, status_type_t type, ++ char *result, int maxlen) ++{ ++ struct dm_snapshot *snap = (struct dm_snapshot *) ti->private; ++ 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: ++ * The context for an origin is merely a 'struct dm_dev *' ++ * pointing to the real device. ++ */ ++static int origin_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ int r; ++ struct dm_dev *dev; ++ ++ if (argc != 1) { ++ ti->error = "dm-origin: incorrect number of arguments"; ++ return -EINVAL; ++ } ++ ++ r = dm_get_device(ti, argv[0], 0, ti->len, ++ dm_table_get_mode(ti->table), &dev); ++ if (r) { ++ ti->error = "Cannot get target device"; ++ return r; ++ } ++ ++ ti->private = dev; ++ ++ return 0; ++} ++ ++static void origin_dtr(struct dm_target *ti) ++{ ++ struct dm_dev *dev = (struct dm_dev *) ti->private; ++ dm_put_device(ti, dev); ++} ++ ++static int origin_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ struct dm_dev *dev = (struct dm_dev *) ti->private; ++ 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(struct dm_target *ti, status_type_t type, char *result, ++ int maxlen) ++{ ++ struct dm_dev *dev = (struct dm_dev *) ti->private; ++ ++ 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, ++}; ++ ++static struct target_type snapshot_target = { ++ name: "snapshot", ++ module: THIS_MODULE, ++ ctr: snapshot_ctr, ++ dtr: snapshot_dtr, ++ map: snapshot_map, ++ status: snapshot_status, ++}; ++ ++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-2.4.20/drivers/md/dm-snapshot.h linux/drivers/md/dm-snapshot.h +--- linux-2.4.20/drivers/md/dm-snapshot.h Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-snapshot.h Wed Mar 26 12:53:19 2003 +@@ -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 ++ ++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 sector_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); ++ ++/* ++ * Return the number of sectors in the device. ++ */ ++static inline sector_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, sector_t sector) ++{ ++ return (sector & ~s->chunk_mask) >> s->chunk_shift; ++} ++ ++static inline sector_t chunk_to_sector(struct dm_snapshot *s, chunk_t chunk) ++{ ++ return chunk << s->chunk_shift; ++} ++ ++#endif +diff -ruN linux-2.4.20/drivers/md/dm-stripe.c linux/drivers/md/dm-stripe.c +--- linux-2.4.20/drivers/md/dm-stripe.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-stripe.c Wed Mar 26 14:07:57 2003 +@@ -0,0 +1,257 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++ ++struct stripe { ++ struct dm_dev *dev; ++ sector_t physical_start; ++}; ++ ++struct stripe_c { ++ uint32_t stripes; ++ ++ /* The size of this target / num. stripes */ ++ uint32_t stripe_width; ++ ++ /* stripe chunk size */ ++ uint32_t chunk_shift; ++ sector_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 pair ++ */ ++static int get_stripe(struct dm_target *ti, struct stripe_c *sc, ++ int stripe, char **argv) ++{ ++ sector_t start; ++ ++ if (sscanf(argv[1], SECTOR_FORMAT, &start) != 1) ++ return -EINVAL; ++ ++ if (dm_get_device(ti, argv[0], start, sc->stripe_width, ++ dm_table_get_mode(ti->table), ++ &sc->stripe[stripe].dev)) ++ return -ENXIO; ++ ++ sc->stripe[stripe].physical_start = start; ++ return 0; ++} ++ ++/* ++ * FIXME: Nasty function, only present because we can't link ++ * against __moddi3 and __divdi3. ++ * ++ * returns a == b * n ++ */ ++static int multiple(sector_t a, sector_t b, sector_t *n) ++{ ++ sector_t acc, prev, i; ++ ++ *n = 0; ++ while (a >= b) { ++ for (acc = b, prev = 0, i = 1; ++ acc <= a; ++ prev = acc, acc <<= 1, i <<= 1) ++ ; ++ ++ a -= prev; ++ *n += i >> 1; ++ } ++ ++ return a == 0; ++} ++ ++/* ++ * Construct a striped mapping. ++ * [ ]+ ++ */ ++static int stripe_ctr(struct dm_target *ti, int argc, char **argv) ++{ ++ struct stripe_c *sc; ++ sector_t width; ++ uint32_t stripes; ++ uint32_t chunk_size; ++ char *end; ++ int r, i; ++ ++ if (argc < 2) { ++ ti->error = "dm-stripe: Not enough arguments"; ++ return -EINVAL; ++ } ++ ++ stripes = simple_strtoul(argv[0], &end, 10); ++ if (*end) { ++ ti->error = "dm-stripe: Invalid stripe count"; ++ return -EINVAL; ++ } ++ ++ chunk_size = simple_strtoul(argv[1], &end, 10); ++ if (*end) { ++ ti->error = "dm-stripe: Invalid chunk_size"; ++ return -EINVAL; ++ } ++ ++ /* ++ * chunk_size is a power of two ++ */ ++ if (!chunk_size || (chunk_size & (chunk_size - 1))) { ++ ti->error = "dm-stripe: Invalid chunk size"; ++ return -EINVAL; ++ } ++ ++ if (!multiple(ti->len, stripes, &width)) { ++ ti->error = "dm-stripe: Target length not divisable by " ++ "number of stripes"; ++ return -EINVAL; ++ } ++ ++ /* ++ * Do we have enough arguments for that many stripes ? ++ */ ++ if (argc != (2 + 2 * stripes)) { ++ ti->error = "dm-stripe: Not enough destinations specified"; ++ return -EINVAL; ++ } ++ ++ sc = alloc_context(stripes); ++ if (!sc) { ++ ti->error = "dm-stripe: Memory allocation for striped context " ++ "failed"; ++ return -ENOMEM; ++ } ++ ++ sc->stripes = stripes; ++ sc->stripe_width = width; ++ ++ sc->chunk_mask = ((sector_t) 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++) { ++ argv += 2; ++ ++ r = get_stripe(ti, sc, i, argv); ++ if (r < 0) { ++ ti->error = "dm-stripe: Couldn't parse stripe " ++ "destination"; ++ while (i--) ++ dm_put_device(ti, sc->stripe[i].dev); ++ kfree(sc); ++ return r; ++ } ++ } ++ ++ ti->private = sc; ++ return 0; ++} ++ ++static void stripe_dtr(struct dm_target *ti) ++{ ++ unsigned int i; ++ struct stripe_c *sc = (struct stripe_c *) ti->private; ++ ++ for (i = 0; i < sc->stripes; i++) ++ dm_put_device(ti, sc->stripe[i].dev); ++ ++ kfree(sc); ++} ++ ++static int stripe_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **context) ++{ ++ struct stripe_c *sc = (struct stripe_c *) ti->private; ++ ++ sector_t offset = bh->b_rsector - ti->begin; ++ 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(struct dm_target *ti, ++ status_type_t type, char *result, int maxlen) ++{ ++ struct stripe_c *sc = (struct stripe_c *) ti->private; ++ int offset; ++ int i; ++ ++ switch (type) { ++ case STATUSTYPE_INFO: ++ result[0] = '\0'; ++ break; ++ ++ case STATUSTYPE_TABLE: ++ offset = snprintf(result, maxlen, "%d " SECTOR_FORMAT, ++ sc->stripes, sc->chunk_mask + 1); ++ for (i = 0; i < sc->stripes; i++) { ++ offset += ++ snprintf(result + offset, maxlen - offset, ++ " %s " SECTOR_FORMAT, ++ kdevname(to_kdev_t(sc->stripe[i].dev->bdev->bd_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-2.4.20/drivers/md/dm-table.c linux/drivers/md/dm-table.c +--- linux-2.4.20/drivers/md/dm-table.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-table.c Wed Mar 26 14:09:13 2003 +@@ -0,0 +1,666 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#define MAX_DEPTH 16 ++#define NODE_SIZE L1_CACHE_BYTES ++#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) ++#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) ++ ++struct dm_table { ++ atomic_t holders; ++ ++ /* btree table */ ++ int depth; ++ int counts[MAX_DEPTH]; /* in nodes */ ++ sector_t *index[MAX_DEPTH]; ++ ++ int num_targets; ++ int num_allocated; ++ sector_t *highs; ++ struct dm_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; ++ ++ /* ++ * A waitqueue for processes waiting for something ++ * interesting to happen to this table. ++ */ ++ wait_queue_head_t eventq; ++}; ++ ++/* ++ * Ceiling(n / size) ++ */ ++static inline unsigned long div_up(unsigned long n, unsigned long size) ++{ ++ return dm_round_up(n, size) / size; ++} ++ ++/* ++ * Similar to ceiling(log_size(n)) ++ */ ++static unsigned int int_log(unsigned long n, unsigned long base) ++{ ++ int result = 0; ++ ++ while (n > 1) { ++ n = div_up(n, base); ++ result++; ++ } ++ ++ return result; ++} ++ ++/* ++ * 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 sector_t *get_node(struct dm_table *t, int l, int n) ++{ ++ return t->index[l] + (n * KEYS_PER_NODE); ++} ++ ++/* ++ * Return the highest key that you could lookup from the n'th ++ * node on level l of the btree. ++ */ ++static sector_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 (sector_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; ++ sector_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) ++{ ++ sector_t *n_highs; ++ struct dm_target *n_targets; ++ int n = t->num_targets; ++ ++ /* ++ * Allocate both the target array and offset array at once. ++ */ ++ n_highs = (sector_t *) vcalloc(sizeof(struct dm_target) + ++ sizeof(sector_t), num); ++ if (!n_highs) ++ return -ENOMEM; ++ ++ n_targets = (struct dm_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)); ++ 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, int mode) ++{ ++ struct dm_table *t = kmalloc(sizeof(*t), GFP_NOIO); ++ ++ if (!t) ++ return -ENOMEM; ++ ++ memset(t, 0, sizeof(*t)); ++ INIT_LIST_HEAD(&t->devices); ++ atomic_set(&t->holders, 1); ++ ++ /* allocate a single nodes worth of targets to begin with */ ++ if (alloc_targets(t, KEYS_PER_NODE)) { ++ kfree(t); ++ t = NULL; ++ return -ENOMEM; ++ } ++ ++ init_waitqueue_head(&t->eventq); ++ t->mode = mode; ++ *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 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 dm_target *tgt = t->targets + i; ++ ++ if (tgt->type->dtr) ++ tgt->type->dtr(tgt); ++ ++ dm_put_target_type(tgt->type); ++ } ++ ++ 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); ++} ++ ++void dm_table_get(struct dm_table *t) ++{ ++ atomic_inc(&t->holders); ++} ++ ++void dm_table_put(struct dm_table *t) ++{ ++ if (atomic_dec_and_test(&t->holders)) ++ table_destroy(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 dev_t. ++ */ ++static 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 out; ++ ++ inode = nd.dentry->d_inode; ++ if (!inode) { ++ r = -ENOENT; ++ goto out; ++ } ++ ++ if (!S_ISBLK(inode->i_mode)) { ++ r = -ENOTBLK; ++ goto out; ++ } ++ ++ *dev = inode->i_rdev; ++ ++ out: ++ 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 (kdev_same(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 *dd) ++{ ++ if (dd->bdev) ++ BUG(); ++ ++ dd->bdev = bdget(kdev_t_to_nr(dd->dev)); ++ if (!dd->bdev) ++ return -ENOMEM; ++ ++ return blkdev_get(dd->bdev, dd->mode, 0, BDEV_RAW); ++} ++ ++/* ++ * Close a device that we've been using. ++ */ ++static void close_dev(struct dm_dev *dd) ++{ ++ if (!dd->bdev) ++ return; ++ ++ blkdev_put(dd->bdev, BDEV_RAW); ++ dd->bdev = 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, sector_t start, sector_t len) ++{ ++ int *sizes; ++ sector_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))); ++} ++ ++/* ++ * 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->bdev = 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_get_device(struct dm_target *ti, const char *path, sector_t start, ++ sector_t len, int mode, struct dm_dev **result) ++{ ++ int r; ++ kdev_t dev; ++ struct dm_dev *dd; ++ int major, minor; ++ struct dm_table *t = ti->table; ++ ++ if (!t) ++ BUG(); ++ ++ if (sscanf(path, "%x:%x", &major, &minor) == 2) { ++ /* Extract the major/minor numbers */ ++ dev = mk_kdev(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->mode = mode; ++ dd->bdev = NULL; ++ ++ if ((r = open_dev(dd))) { ++ kfree(dd); ++ return r; ++ } ++ ++ 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); ++ ++ if (!check_device_area(dd->dev, start, len)) { ++ DMWARN("device %s too small for target", path); ++ dm_put_device(ti, dd); ++ return -EINVAL; ++ } ++ ++ *result = dd; ++ ++ return 0; ++} ++ ++/* ++ * Decrement a devices use count and remove it if neccessary. ++ */ ++void dm_put_device(struct dm_target *ti, struct dm_dev *dd) ++{ ++ if (atomic_dec_and_test(&dd->count)) { ++ close_dev(dd); ++ list_del(&dd->list); ++ kfree(dd); ++ } ++} ++ ++/* ++ * Checks to see if the target joins onto the end of the table. ++ */ ++static int adjoin(struct dm_table *table, struct dm_target *ti) ++{ ++ struct dm_target *prev; ++ ++ if (!table->num_targets) ++ return !ti->begin; ++ ++ prev = &table->targets[table->num_targets - 1]; ++ return (ti->begin == (prev->begin + prev->len)); ++} ++ ++/* ++ * Destructively splits up the argument list to pass to ctr. ++ */ ++static 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; ++} ++ ++int dm_table_add_target(struct dm_table *t, const char *type, ++ sector_t start, sector_t len, char *params) ++{ ++ int r = -EINVAL, argc; ++ char *argv[32]; ++ struct dm_target *tgt; ++ ++ if ((r = check_space(t))) ++ return r; ++ ++ tgt = t->targets + t->num_targets; ++ memset(tgt, 0, sizeof(*tgt)); ++ ++ tgt->type = dm_get_target_type(type); ++ if (!tgt->type) { ++ tgt->error = "unknown target type"; ++ return -EINVAL; ++ } ++ ++ tgt->table = t; ++ tgt->begin = start; ++ tgt->len = len; ++ tgt->error = "Unknown error"; ++ ++ /* ++ * Does this target adjoin the previous one ? ++ */ ++ if (!adjoin(t, tgt)) { ++ tgt->error = "Gap in table"; ++ r = -EINVAL; ++ goto bad; ++ } ++ ++ r = split_args(ARRAY_SIZE(argv), &argc, argv, params); ++ if (r) { ++ tgt->error = "couldn't split parameters"; ++ goto bad; ++ } ++ ++ r = tgt->type->ctr(tgt, argc, argv); ++ if (r) ++ goto bad; ++ ++ t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; ++ return 0; ++ ++ bad: ++ printk(KERN_ERR DM_NAME ": %s\n", tgt->error); ++ dm_put_target_type(tgt->type); ++ return r; ++} ++ ++static int setup_indexes(struct dm_table *t) ++{ ++ int i, total = 0; ++ sector_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 = (sector_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); ++} ++ ++sector_t dm_table_get_size(struct dm_table *t) ++{ ++ return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; ++} ++ ++struct dm_target *dm_table_get_target(struct dm_table *t, int index) ++{ ++ if (index > t->num_targets) ++ return NULL; ++ ++ return t->targets + index; ++} ++ ++/* ++ * Search the btree for the correct target. ++ */ ++struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) ++{ ++ int l, n = 0, k = 0; ++ sector_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] >= sector) ++ break; ++ } ++ ++ return &t->targets[(KEYS_PER_NODE * n) + k]; ++} ++ ++unsigned int dm_table_get_num_targets(struct dm_table *t) ++{ ++ return t->num_targets; ++} ++ ++struct list_head *dm_table_get_devices(struct dm_table *t) ++{ ++ return &t->devices; ++} ++ ++int dm_table_get_mode(struct dm_table *t) ++{ ++ return t->mode; ++} ++ ++void dm_table_add_wait_queue(struct dm_table *t, wait_queue_t *wq) ++{ ++ add_wait_queue(&t->eventq, wq); ++} ++ ++EXPORT_SYMBOL(dm_get_device); ++EXPORT_SYMBOL(dm_put_device); ++EXPORT_SYMBOL(dm_table_event); ++EXPORT_SYMBOL(dm_table_get_mode); +diff -ruN linux-2.4.20/drivers/md/dm-target.c linux/drivers/md/dm-target.c +--- linux-2.4.20/drivers/md/dm-target.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm-target.c Wed Mar 26 12:54:14 2003 +@@ -0,0 +1,187 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++ ++struct tt_internal { ++ struct target_type tt; ++ ++ struct list_head list; ++ long use; ++}; ++ ++static LIST_HEAD(_targets); ++static DECLARE_RWSEM(_lock); ++ ++#define DM_MOD_NAME_SIZE 32 ++ ++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; ++ ++ down_read(&_lock); ++ ti = __find_target_type(name); ++ ++ if (ti) { ++ if (ti->use == 0 && ti->tt.module) ++ __MOD_INC_USE_COUNT(ti->tt.module); ++ ti->use++; ++ } ++ up_read(&_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); ++} ++ ++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; ++ ++ down_read(&_lock); ++ if (--ti->use == 0 && ti->tt.module) ++ __MOD_DEC_USE_COUNT(ti->tt.module); ++ ++ if (ti->use < 0) ++ BUG(); ++ up_read(&_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; ++ ++ down_write(&_lock); ++ if (__find_target_type(t->name)) ++ rv = -EEXIST; ++ else ++ list_add(&ti->list, &_targets); ++ ++ up_write(&_lock); ++ return rv; ++} ++ ++int dm_unregister_target(struct target_type *t) ++{ ++ struct tt_internal *ti; ++ ++ down_write(&_lock); ++ if (!(ti = __find_target_type(t->name))) { ++ up_write(&_lock); ++ return -EINVAL; ++ } ++ ++ if (ti->use) { ++ up_write(&_lock); ++ return -ETXTBSY; ++ } ++ ++ list_del(&ti->list); ++ kfree(ti); ++ ++ up_write(&_lock); ++ return 0; ++} ++ ++/* ++ * io-err: always fails an io, useful for bringing ++ * up LVs that have holes in them. ++ */ ++static int io_err_ctr(struct dm_target *ti, int argc, char **args) ++{ ++ return 0; ++} ++ ++static void io_err_dtr(struct dm_target *ti) ++{ ++ /* empty */ ++} ++ ++static int io_err_map(struct dm_target *ti, struct buffer_head *bh, int rw, ++ void **map_context) ++{ ++ return -EIO; ++} ++ ++static struct target_type error_target = { ++ .name = "error", ++ .ctr = io_err_ctr, ++ .dtr = io_err_dtr, ++ .map = io_err_map, ++}; ++ ++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-2.4.20/drivers/md/dm.c linux/drivers/md/dm.c +--- linux-2.4.20/drivers/md/dm.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm.c Wed Mar 26 14:23:27 2003 +@@ -0,0 +1,878 @@ ++/* ++ * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include "dm.h" ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include ++ ++static const char *_name = DM_NAME; ++#define MAX_DEVICES (1 << MINORBITS) ++#define DEFAULT_READ_AHEAD 64 ++ ++static int major = 0; ++static int _major = 0; ++ ++struct dm_io { ++ struct mapped_device *md; ++ ++ struct dm_target *ti; ++ int rw; ++ void *map_context; ++ void (*end_io) (struct buffer_head * bh, int uptodate); ++ void *context; ++}; ++ ++struct deferred_io { ++ int rw; ++ struct buffer_head *bh; ++ struct deferred_io *next; ++}; ++ ++/* ++ * Bits for the md->flags field. ++ */ ++#define DMF_BLOCK_IO 0 ++#define DMF_SUSPENDED 1 ++ ++struct mapped_device { ++ struct rw_semaphore lock; ++ atomic_t holders; ++ ++ kdev_t dev; ++ unsigned long flags; ++ ++ /* ++ * A list of ios that arrived while we were suspended. ++ */ ++ atomic_t pending; ++ wait_queue_head_t wait; ++ struct deferred_io *deferred; ++ ++ /* ++ * The current mapping. ++ */ ++ struct dm_table *map; ++ ++ /* ++ * io objects are allocated from here. ++ */ ++ mempool_t *io_pool; ++}; ++ ++#define MIN_IOS 256 ++static kmem_cache_t *_io_cache; ++ ++/* block device arrays */ ++static int _block_size[MAX_DEVICES]; ++static int _blksize_size[MAX_DEVICES]; ++static int _hardsect_size[MAX_DEVICES]; ++ ++static struct mapped_device *get_kdev(kdev_t dev); ++static int dm_request(request_queue_t *q, int rw, struct buffer_head *bh); ++static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb); ++ ++static __init int local_init(void) ++{ ++ int r; ++ ++ /* allocate a slab for the dm_ios */ ++ _io_cache = kmem_cache_create("dm io", ++ sizeof(struct dm_io), 0, 0, NULL, NULL); ++ ++ if (!_io_cache) ++ return -ENOMEM; ++ ++ _major = major; ++ r = register_blkdev(_major, _name, &dm_blk_dops); ++ if (r < 0) { ++ DMERR("register_blkdev failed"); ++ kmem_cache_destroy(_io_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), dm_request); ++ ++ return 0; ++} ++ ++static void local_exit(void) ++{ ++ kmem_cache_destroy(_io_cache); ++ ++ if (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) ++ xx(dm_linear) ++ xx(dm_stripe) ++ xx(dm_snapshot) ++ xx(dm_interface) ++#undef xx ++}; ++ ++static int __init dm_init(void) ++{ ++ const int count = ARRAY_SIZE(_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 = ARRAY_SIZE(_inits); ++ ++ while (i--) ++ _inits[i].exit(); ++} ++ ++/* ++ * Block device functions ++ */ ++static int dm_blk_open(struct inode *inode, struct file *file) ++{ ++ struct mapped_device *md; ++ ++ md = get_kdev(inode->i_rdev); ++ if (!md) ++ return -ENXIO; ++ ++ return 0; ++} ++ ++static int dm_blk_close(struct inode *inode, struct file *file) ++{ ++ struct mapped_device *md; ++ ++ md = get_kdev(inode->i_rdev); ++ dm_put(md); /* put the reference gained by dm_blk_open */ ++ dm_put(md); ++ return 0; ++} ++ ++static inline struct dm_io *alloc_io(struct mapped_device *md) ++{ ++ return mempool_alloc(md->io_pool, GFP_NOIO); ++} ++ ++static inline void free_io(struct mapped_device *md, struct dm_io *io) ++{ ++ mempool_free(io, md->io_pool); ++} ++ ++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); ++} ++ ++/* In 512-byte units */ ++#define VOLUME_SIZE(minor) (_block_size[(minor)] << 1) ++ ++/* FIXME: check this */ ++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; ++} ++ ++/* ++ * Add the buffer to the list of deferred io. ++ */ ++static int queue_io(struct mapped_device *md, struct buffer_head *bh, int rw) ++{ ++ struct deferred_io *di; ++ ++ di = alloc_deferred(); ++ if (!di) ++ return -ENOMEM; ++ ++ down_write(&md->lock); ++ ++ if (!test_bit(DMF_BLOCK_IO, &md->flags)) { ++ up_write(&md->lock); ++ free_deferred(di); ++ return 1; ++ } ++ ++ di->bh = bh; ++ di->rw = rw; ++ di->next = md->deferred; ++ md->deferred = di; ++ ++ up_write(&md->lock); ++ return 0; /* deferred successfully */ ++} ++ ++/* ++ * 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) ++{ ++ int r; ++ struct dm_io *io = bh->b_private; ++ dm_endio_fn endio = io->ti->type->end_io; ++ ++ if (endio) { ++ r = endio(io->ti, bh, io->rw, uptodate ? 0 : -EIO, ++ io->map_context); ++ if (r < 0) ++ uptodate = 0; ++ ++ else if (r > 0) ++ /* the target wants another shot at the io */ ++ return; ++ } ++ ++ if (atomic_dec_and_test(&io->md->pending)) ++ /* nudge anyone waiting on suspend queue */ ++ wake_up(&io->md->wait); ++ ++ bh->b_end_io = io->end_io; ++ bh->b_private = io->context; ++ free_io(io->md, io); ++ ++ bh->b_end_io(bh, uptodate); ++} ++ ++/* ++ * Do the bh mapping for a given leaf ++ */ ++static inline int __map_buffer(struct mapped_device *md, int rw, ++ struct buffer_head *bh, struct dm_io *io) ++{ ++ struct dm_target *ti; ++ ++ ti = dm_table_find_target(md->map, bh->b_rsector); ++ if (!ti || !ti->type) ++ return -EINVAL; ++ ++ /* hook the end io request fn */ ++ atomic_inc(&md->pending); ++ io->md = md; ++ io->ti = ti; ++ io->rw = rw; ++ io->end_io = bh->b_end_io; ++ io->context = bh->b_private; ++ bh->b_end_io = dec_pending; ++ bh->b_private = io; ++ ++ return ti->type->map(ti, bh, rw, &io->map_context); ++} ++ ++/* ++ * Checks to see if we should be deferring io, if so it queues it ++ * and returns 1. ++ */ ++static inline int __deferring(struct mapped_device *md, int rw, ++ struct buffer_head *bh) ++{ ++ int r; ++ ++ /* ++ * If we're suspended we have to queue this io for later. ++ */ ++ while (test_bit(DMF_BLOCK_IO, &md->flags)) { ++ up_read(&md->lock); ++ ++ /* ++ * There's no point deferring a read ahead ++ * request, just drop it. ++ */ ++ if (rw == READA) { ++ down_read(&md->lock); ++ return -EIO; ++ } ++ ++ r = queue_io(md, bh, rw); ++ down_read(&md->lock); ++ ++ if (r < 0) ++ return r; ++ ++ if (r == 0) ++ return 1; /* deferred successfully */ ++ ++ } ++ ++ return 0; ++} ++ ++static int dm_request(request_queue_t *q, int rw, struct buffer_head *bh) ++{ ++ int r; ++ struct dm_io *io; ++ struct mapped_device *md; ++ ++ md = get_kdev(bh->b_rdev); ++ if (!md) { ++ buffer_IO_error(bh); ++ return 0; ++ } ++ ++ io = alloc_io(md); ++ down_read(&md->lock); ++ ++ r = __deferring(md, rw, bh); ++ if (r < 0) ++ goto bad; ++ ++ else if (!r) { ++ /* not deferring */ ++ r = __map_buffer(md, rw, bh, io); ++ if (r < 0) ++ goto bad; ++ } else ++ r = 0; ++ ++ up_read(&md->lock); ++ dm_put(md); ++ return r; ++ ++ bad: ++ buffer_IO_error(bh); ++ up_read(&md->lock); ++ dm_put(md); ++ return 0; ++} ++ ++static int check_dev_size(kdev_t dev, unsigned long block) ++{ ++ /* FIXME: check this */ ++ int minor = MINOR(dev); ++ 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 __bmap(struct mapped_device *md, kdev_t dev, unsigned long block, ++ kdev_t *r_dev, unsigned long *r_block) ++{ ++ struct buffer_head bh; ++ struct dm_target *ti; ++ void *map_context; ++ int r; ++ ++ if (test_bit(DMF_BLOCK_IO, &md->flags)) { ++ return -EPERM; ++ } ++ ++ if (!check_dev_size(dev, block)) { ++ 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(dev)]; ++ bh.b_rsector = block * (bh.b_size >> 9); ++ ++ /* find target */ ++ ti = dm_table_find_target(md->map, bh.b_rsector); ++ ++ /* do the mapping */ ++ r = ti->type->map(ti, &bh, READ, &map_context); ++ ti->type->end_io(ti, &bh, READ, 0, map_context); ++ ++ if (!r) { ++ *r_dev = bh.b_rdev; ++ *r_block = bh.b_rsector / (bh.b_size >> 9); ++ } ++ ++ return r; ++} ++ ++/* ++ * Marshals arguments and results between user and kernel space. ++ */ ++static int dm_user_bmap(struct inode *inode, struct lv_bmap *lvb) ++{ ++ struct mapped_device *md; ++ unsigned long block, r_block; ++ kdev_t r_dev; ++ int r; ++ ++ if (get_user(block, &lvb->lv_block)) ++ return -EFAULT; ++ ++ md = get_kdev(inode->i_rdev); ++ if (!md) ++ return -ENXIO; ++ ++ down_read(&md->lock); ++ r = __bmap(md, inode->i_rdev, block, &r_dev, &r_block); ++ up_read(&md->lock); ++ dm_put(md); ++ ++ if (!r && (put_user(kdev_t_to_nr(r_dev), &lvb->lv_dev) || ++ put_user(r_block, &lvb->lv_block))) ++ r = -EFAULT; ++ ++ return r; ++} ++ ++/*----------------------------------------------------------------- ++ * A bitset is used to keep track of allocated minor numbers. ++ *---------------------------------------------------------------*/ ++static spinlock_t _minor_lock = SPIN_LOCK_UNLOCKED; ++static struct mapped_device *_mds[MAX_DEVICES]; ++ ++static void free_minor(int minor) ++{ ++ spin_lock(&_minor_lock); ++ _mds[minor] = NULL; ++ spin_unlock(&_minor_lock); ++} ++ ++/* ++ * See if the device with a specific minor # is free. ++ */ ++static int specific_minor(int minor, struct mapped_device *md) ++{ ++ int r = -EBUSY; ++ ++ if (minor >= MAX_DEVICES) { ++ DMWARN("request for a mapped_device beyond MAX_DEVICES (%d)", ++ MAX_DEVICES); ++ return -EINVAL; ++ } ++ ++ spin_lock(&_minor_lock); ++ if (!_mds[minor]) { ++ _mds[minor] = md; ++ r = minor; ++ } ++ spin_unlock(&_minor_lock); ++ ++ return r; ++} ++ ++static int next_free_minor(struct mapped_device *md) ++{ ++ int i; ++ ++ spin_lock(&_minor_lock); ++ for (i = 0; i < MAX_DEVICES; i++) { ++ if (!_mds[i]) { ++ _mds[i] = md; ++ break; ++ } ++ } ++ spin_unlock(&_minor_lock); ++ ++ return (i < MAX_DEVICES) ? i : -EBUSY; ++} ++ ++static struct mapped_device *get_kdev(kdev_t dev) ++{ ++ struct mapped_device *md; ++ ++ if (major(dev) != _major) ++ return NULL; ++ ++ spin_lock(&_minor_lock); ++ md = _mds[minor(dev)]; ++ if (md) ++ dm_get(md); ++ spin_unlock(&_minor_lock); ++ ++ return md; ++} ++ ++/* ++ * Allocate and initialise a blank device with a given minor. ++ */ ++static struct mapped_device *alloc_dev(int minor) ++{ ++ struct mapped_device *md = kmalloc(sizeof(*md), GFP_KERNEL); ++ ++ if (!md) { ++ DMWARN("unable to allocate device, out of memory."); ++ return NULL; ++ } ++ ++ /* get a minor number for the dev */ ++ minor = (minor < 0) ? next_free_minor(md) : specific_minor(minor, md); ++ if (minor < 0) { ++ kfree(md); ++ return NULL; ++ } ++ ++ memset(md, 0, sizeof(*md)); ++ ++ md->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab, ++ mempool_free_slab, _io_cache); ++ if (!md->io_pool) { ++ free_minor(minor); ++ kfree(md); ++ return NULL; ++ } ++ ++ md->dev = mk_kdev(_major, minor); ++ init_rwsem(&md->lock); ++ atomic_set(&md->holders, 1); ++ atomic_set(&md->pending, 0); ++ init_waitqueue_head(&md->wait); ++ ++ return md; ++} ++ ++static void free_dev(struct mapped_device *md) ++{ ++ free_minor(minor(md->dev)); ++ mempool_destroy(md->io_pool); ++ kfree(md); ++} ++ ++/* ++ * The hardsect size for a mapped device is the largest hardsect size ++ * from the devices it maps onto. ++ */ ++static int __find_hardsect_size(struct list_head *devices) ++{ ++ int result = 512, 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; ++ ++ /* in k */ ++ _block_size[minor] = dm_table_get_size(t) >> 1; ++ _blksize_size[minor] = BLOCK_SIZE; ++ _hardsect_size[minor] = __find_hardsect_size(dm_table_get_devices(t)); ++ register_disk(NULL, md->dev, 1, &dm_blk_dops, _block_size[minor]); ++ ++ dm_table_get(t); ++ return 0; ++} ++ ++static void __unbind(struct mapped_device *md) ++{ ++ int minor = minor(md->dev); ++ ++ dm_table_put(md->map); ++ md->map = NULL; ++ ++ _block_size[minor] = 0; ++ _blksize_size[minor] = 0; ++ _hardsect_size[minor] = 0; ++} ++ ++/* ++ * Constructor for a new device. ++ */ ++int dm_create(int minor, struct dm_table *table, struct mapped_device **result) ++{ ++ int r; ++ struct mapped_device *md; ++ ++ md = alloc_dev(minor); ++ if (!md) ++ return -ENXIO; ++ ++ r = __bind(md, table); ++ if (r) { ++ free_dev(md); ++ return r; ++ } ++ ++ *result = md; ++ return 0; ++} ++ ++void dm_get(struct mapped_device *md) ++{ ++ atomic_inc(&md->holders); ++} ++ ++void dm_put(struct mapped_device *md) ++{ ++ if (atomic_dec_and_test(&md->holders)) { ++ __unbind(md); ++ free_dev(md); ++ } ++} ++ ++/* ++ * Requeue the deferred io 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). ++ */ ++int dm_swap_table(struct mapped_device *md, struct dm_table *table) ++{ ++ int r; ++ ++ down_write(&md->lock); ++ ++ /* device must be suspended */ ++ if (!test_bit(DMF_SUSPENDED, &md->flags)) { ++ up_write(&md->lock); ++ return -EPERM; ++ } ++ ++ __unbind(md); ++ r = __bind(md, table); ++ if (r) ++ return r; ++ ++ up_write(&md->lock); ++ 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 io and ensure that any further io gets deferred. ++ */ ++int dm_suspend(struct mapped_device *md) ++{ ++ DECLARE_WAITQUEUE(wait, current); ++ ++ down_write(&md->lock); ++ ++ /* ++ * First we set the BLOCK_IO flag so no more ios will be ++ * mapped. ++ */ ++ if (test_bit(DMF_BLOCK_IO, &md->flags)) { ++ up_write(&md->lock); ++ return -EINVAL; ++ } ++ ++ set_bit(DMF_BLOCK_IO, &md->flags); ++ add_wait_queue(&md->wait, &wait); ++ up_write(&md->lock); ++ ++ /* ++ * Then we wait for the already mapped ios to ++ * complete. ++ */ ++ run_task_queue(&tq_disk); ++ while (1) { ++ set_current_state(TASK_INTERRUPTIBLE); ++ ++ if (!atomic_read(&md->pending)) ++ break; ++ ++ schedule(); ++ } ++ ++ current->state = TASK_RUNNING; ++ ++ down_write(&md->lock); ++ remove_wait_queue(&md->wait, &wait); ++ set_bit(DMF_SUSPENDED, &md->flags); ++ up_write(&md->lock); ++ ++ return 0; ++} ++ ++int dm_resume(struct mapped_device *md) ++{ ++ struct deferred_io *def; ++ ++ down_write(&md->lock); ++ if (!test_bit(DMF_SUSPENDED, &md->flags) || ++ !dm_table_get_size(md->map)) { ++ up_write(&md->lock); ++ return -EINVAL; ++ } ++ ++ clear_bit(DMF_SUSPENDED, &md->flags); ++ clear_bit(DMF_BLOCK_IO, &md->flags); ++ def = md->deferred; ++ md->deferred = NULL; ++ up_write(&md->lock); ++ ++ flush_deferred_io(def); ++ run_task_queue(&tq_disk); ++ ++ return 0; ++} ++ ++struct dm_table *dm_get_table(struct mapped_device *md) ++{ ++ struct dm_table *t; ++ ++ down_read(&md->lock); ++ t = md->map; ++ dm_table_get(t); ++ up_read(&md->lock); ++ ++ return t; ++} ++ ++kdev_t dm_kdev(struct mapped_device *md) ++{ ++ kdev_t dev; ++ ++ down_read(&md->lock); ++ dev = md->dev; ++ up_read(&md->lock); ++ ++ return dev; ++} ++ ++int dm_suspended(struct mapped_device *md) ++{ ++ return test_bit(DMF_SUSPENDED, &md->flags); ++} ++ ++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 "); ++MODULE_LICENSE("GPL"); +diff -ruN linux-2.4.20/drivers/md/dm.h linux/drivers/md/dm.h +--- linux-2.4.20/drivers/md/dm.h Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/dm.h Wed Mar 26 14:12:00 2003 +@@ -0,0 +1,154 @@ ++/* ++ * Internal header file for device mapper ++ * ++ * Copyright (C) 2001, 2002 Sistina Software ++ * ++ * This file is released under the LGPL. ++ */ ++ ++#ifndef DM_INTERNAL_H ++#define DM_INTERNAL_H ++ ++#include ++#include ++#include ++#include ++ ++#define DM_NAME "device-mapper" ++#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) ++ ++/* ++ * FIXME: I think this should be with the definition of sector_t ++ * in types.h. ++ */ ++#ifdef CONFIG_LBD ++#define SECTOR_FORMAT "%Lu" ++#else ++#define SECTOR_FORMAT "%lu" ++#endif ++ ++#define SECTOR_SHIFT 9 ++#define SECTOR_SIZE (1 << SECTOR_SHIFT) ++ ++extern struct block_device_operations dm_blk_dops; ++ ++/* ++ * List of devices that a metadevice uses and should open/close. ++ */ ++struct dm_dev { ++ struct list_head list; ++ ++ atomic_t count; ++ int mode; ++ kdev_t dev; ++ struct block_device *bdev; ++}; ++ ++struct dm_table; ++struct mapped_device; ++ ++/*----------------------------------------------------------------- ++ * Functions for manipulating a struct mapped_device. ++ * Drop the reference with dm_put when you finish with the object. ++ *---------------------------------------------------------------*/ ++int dm_create(int minor, struct dm_table *table, struct mapped_device **md); ++ ++/* ++ * Reference counting for md. ++ */ ++void dm_get(struct mapped_device *md); ++void dm_put(struct mapped_device *md); ++ ++/* ++ * 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); ++ ++/* ++ * The device must be suspended before calling this method. ++ */ ++int dm_swap_table(struct mapped_device *md, struct dm_table *t); ++ ++/* ++ * Drop a reference on the table when you've finished with the ++ * result. ++ */ ++struct dm_table *dm_get_table(struct mapped_device *md); ++ ++/* ++ * Info functions. ++ */ ++kdev_t dm_kdev(struct mapped_device *md); ++int dm_suspended(struct mapped_device *md); ++ ++/*----------------------------------------------------------------- ++ * Functions for manipulating a table. Tables are also reference ++ * counted. ++ *---------------------------------------------------------------*/ ++int dm_table_create(struct dm_table **result, int mode); ++ ++void dm_table_get(struct dm_table *t); ++void dm_table_put(struct dm_table *t); ++ ++int dm_table_add_target(struct dm_table *t, const char *type, ++ sector_t start, sector_t len, char *params); ++int dm_table_complete(struct dm_table *t); ++void dm_table_event(struct dm_table *t); ++sector_t dm_table_get_size(struct dm_table *t); ++struct dm_target *dm_table_get_target(struct dm_table *t, int index); ++struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector); ++unsigned int dm_table_get_num_targets(struct dm_table *t); ++struct list_head *dm_table_get_devices(struct dm_table *t); ++int dm_table_get_mode(struct dm_table *t); ++void dm_table_add_wait_queue(struct dm_table *t, wait_queue_t *wq); ++ ++/*----------------------------------------------------------------- ++ * A registry of target types. ++ *---------------------------------------------------------------*/ ++int dm_target_init(void); ++void dm_target_exit(void); ++struct target_type *dm_get_target_type(const char *name); ++void dm_put_target_type(struct target_type *t); ++ ++ ++/*----------------------------------------------------------------- ++ * Useful inlines. ++ *---------------------------------------------------------------*/ ++static inline int array_too_big(unsigned long fixed, unsigned long obj, ++ unsigned long num) ++{ ++ return (num > (ULONG_MAX - fixed) / obj); ++} ++ ++/* ++ * ceiling(n / size) * size ++ */ ++static inline unsigned long dm_round_up(unsigned long n, unsigned long size) ++{ ++ unsigned long r = n % size; ++ return n + (r ? (size - r) : 0); ++} ++ ++/* ++ * The device-mapper can be driven through one of two interfaces; ++ * ioctl or filesystem, depending which patch you have applied. ++ */ ++int 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); ++ ++#endif +diff -ruN linux-2.4.20/drivers/md/kcopyd.c linux/drivers/md/kcopyd.c +--- linux-2.4.20/drivers/md/kcopyd.c Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/kcopyd.c Wed Mar 26 12:54:17 2003 +@@ -0,0 +1,839 @@ ++/* ++ * Copyright (C) 2002 Sistina Software (UK) Limited. ++ * ++ * This file is released under the GPL. ++ */ ++ ++#include ++ ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++#include ++ ++#include "kcopyd.h" ++ ++/* FIXME: this is only needed for the DMERR macros */ ++#include "dm.h" ++ ++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--) { ++ UnlockPage(_pages_array[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, 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(); ++} ++ ++/*----------------------------------------------------------------- ++ * 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_NOIO); ++ 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_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; ++ atomic_set(&bh->b_count, 1); ++ ++ bh->b_state = ((1 << BH_Uptodate) | (1 << BH_Mapped) | ++ (1 << BH_Lock) | (1 << BH_Req)); ++ ++ 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't 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_NOIO); ++} ++ ++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) { ++ if (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; ++ ++ /* ++ * 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; ++ 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; ++ 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-2.4.20/drivers/md/kcopyd.h linux/drivers/md/kcopyd.h +--- linux-2.4.20/drivers/md/kcopyd.h Thu Jan 1 01:00:00 1970 ++++ linux/drivers/md/kcopyd.h Wed Mar 26 14:14:34 2003 +@@ -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 ++#include ++ ++struct kcopyd_region { ++ kdev_t dev; ++ sector_t sector; ++ sector_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. ++ */ ++ sector_t offset; ++ sector_t block_size; ++ sector_t block_shift; ++ sector_t bpp_shift; /* blocks per page */ ++ sector_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 +diff -ruN linux-2.4.20/fs/buffer.c linux/fs/buffer.c +--- linux-2.4.20/fs/buffer.c Fri Jan 10 16:35:24 2003 ++++ linux/fs/buffer.c Wed Mar 26 12:53:19 2003 +@@ -586,9 +586,10 @@ + void buffer_insert_inode_queue(struct buffer_head *bh, struct inode *inode) + { + spin_lock(&lru_list_lock); +- if (bh->b_inode) ++ if (buffer_inode(bh)) + list_del(&bh->b_inode_buffers); +- bh->b_inode = inode; ++ else ++ set_buffer_inode(bh); + list_add(&bh->b_inode_buffers, &inode->i_dirty_buffers); + spin_unlock(&lru_list_lock); + } +@@ -596,9 +597,10 @@ + void buffer_insert_inode_data_queue(struct buffer_head *bh, struct inode *inode) + { + spin_lock(&lru_list_lock); +- if (bh->b_inode) ++ if (buffer_inode(bh)) + list_del(&bh->b_inode_buffers); +- bh->b_inode = inode; ++ else ++ set_buffer_inode(bh); + list_add(&bh->b_inode_buffers, &inode->i_dirty_data_buffers); + spin_unlock(&lru_list_lock); + } +@@ -607,13 +609,13 @@ + remove_inode_queue functions. */ + static void __remove_inode_queue(struct buffer_head *bh) + { +- bh->b_inode = NULL; ++ clear_buffer_inode(bh); + list_del(&bh->b_inode_buffers); + } + + static inline void remove_inode_queue(struct buffer_head *bh) + { +- if (bh->b_inode) ++ if (buffer_inode(bh)) + __remove_inode_queue(bh); + } + +@@ -741,6 +743,7 @@ + bh->b_list = BUF_CLEAN; + bh->b_end_io = handler; + bh->b_private = private; ++ bh->b_journal_head = NULL; + } + + static void end_buffer_io_async(struct buffer_head * bh, int uptodate) +@@ -842,9 +845,9 @@ + bh = BH_ENTRY(list->next); + list_del(&bh->b_inode_buffers); + if (!buffer_dirty(bh) && !buffer_locked(bh)) +- bh->b_inode = NULL; ++ clear_buffer_inode(bh); + else { +- bh->b_inode = &tmp; ++ set_buffer_inode(bh); + list_add(&bh->b_inode_buffers, &tmp.i_dirty_buffers); + if (buffer_dirty(bh)) { + get_bh(bh); +@@ -1138,7 +1141,7 @@ + */ + static void __put_unused_buffer_head(struct buffer_head * bh) + { +- if (bh->b_inode) ++ if (buffer_inode(bh)) + BUG(); + if (nr_unused_buffer_heads >= MAX_UNUSED_BUFFERS) { + kmem_cache_free(bh_cachep, bh); +diff -ruN linux-2.4.20/fs/jbd/journal.c linux/fs/jbd/journal.c +--- linux-2.4.20/fs/jbd/journal.c Fri Jan 10 16:35:27 2003 ++++ linux/fs/jbd/journal.c Wed Mar 26 12:53:19 2003 +@@ -1664,8 +1664,8 @@ + * + * Whenever a buffer has an attached journal_head, its ->b_state:BH_JBD bit + * is set. This bit is tested in core kernel code where we need to take +- * JBD-specific actions. Testing the zeroness of ->b_private is not reliable +- * there. ++ * JBD-specific actions. Testing the zeroness of ->b_journal_head is not ++ * reliable there. + * + * When a buffer has its BH_JBD bit set, its ->b_count is elevated by one. + * +@@ -1720,9 +1720,9 @@ + + if (buffer_jbd(bh)) { + /* Someone did it for us! */ +- J_ASSERT_BH(bh, bh->b_private != NULL); ++ J_ASSERT_BH(bh, bh->b_journal_head != NULL); + journal_free_journal_head(jh); +- jh = bh->b_private; ++ jh = bh->b_journal_head; + } else { + /* + * We actually don't need jh_splice_lock when +@@ -1730,7 +1730,7 @@ + */ + spin_lock(&jh_splice_lock); + set_bit(BH_JBD, &bh->b_state); +- bh->b_private = jh; ++ bh->b_journal_head = jh; + jh->b_bh = bh; + atomic_inc(&bh->b_count); + spin_unlock(&jh_splice_lock); +@@ -1739,7 +1739,7 @@ + } + jh->b_jcount++; + spin_unlock(&journal_datalist_lock); +- return bh->b_private; ++ return bh->b_journal_head; + } + + /* +@@ -1772,7 +1772,7 @@ + J_ASSERT_BH(bh, jh2bh(jh) == bh); + BUFFER_TRACE(bh, "remove journal_head"); + spin_lock(&jh_splice_lock); +- bh->b_private = NULL; ++ bh->b_journal_head = NULL; + jh->b_bh = NULL; /* debug, really */ + clear_bit(BH_JBD, &bh->b_state); + __brelse(bh); +diff -ruN linux-2.4.20/include/linux/device-mapper.h linux/include/linux/device-mapper.h +--- linux-2.4.20/include/linux/device-mapper.h Thu Jan 1 01:00:00 1970 ++++ linux/include/linux/device-mapper.h Wed Mar 26 14:14:55 2003 +@@ -0,0 +1,94 @@ ++/* ++ * Copyright (C) 2001 Sistina Software (UK) Limited. ++ * ++ * This file is released under the LGPL. ++ */ ++ ++#ifndef _LINUX_DEVICE_MAPPER_H ++#define _LINUX_DEVICE_MAPPER_H ++ ++typedef unsigned long sector_t; ++ ++struct dm_target; ++struct dm_table; ++struct dm_dev; ++ ++typedef enum { STATUSTYPE_INFO, STATUSTYPE_TABLE } status_type_t; ++ ++/* ++ * In the constructor the target parameter will already have the ++ * table, type, begin and len fields filled in. ++ */ ++typedef int (*dm_ctr_fn) (struct dm_target * target, int argc, char **argv); ++ ++/* ++ * The destructor doesn't need to free the dm_target, just ++ * anything hidden ti->private. ++ */ ++typedef void (*dm_dtr_fn) (struct dm_target * ti); ++ ++/* ++ * The map function must return: ++ * < 0: error ++ * = 0: The target will handle the io by resubmitting it later ++ * > 0: simple remap complete ++ */ ++typedef int (*dm_map_fn) (struct dm_target * ti, struct buffer_head * bh, ++ int rw, void **map_context); ++ ++/* ++ * Returns: ++ * < 0 : error (currently ignored) ++ * 0 : ended successfully ++ * 1 : for some reason the io has still not completed (eg, ++ * multipath target might want to requeue a failed io). ++ */ ++typedef int (*dm_endio_fn) (struct dm_target * ti, ++ struct buffer_head * bh, int rw, int error, ++ void *map_context); ++typedef int (*dm_status_fn) (struct dm_target * ti, status_type_t status_type, ++ char *result, int maxlen); ++ ++void dm_error(const char *message); ++ ++/* ++ * Constructors should call these functions to ensure destination devices ++ * are opened/closed correctly. ++ * FIXME: too many arguments. ++ */ ++int dm_get_device(struct dm_target *ti, const char *path, sector_t start, ++ sector_t len, int mode, struct dm_dev **result); ++void dm_put_device(struct dm_target *ti, 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_endio_fn end_io; ++ dm_status_fn status; ++}; ++ ++struct dm_target { ++ struct dm_table *table; ++ struct target_type *type; ++ ++ /* target limits */ ++ sector_t begin; ++ sector_t len; ++ ++ /* target specific data */ ++ void *private; ++ ++ /* Used to provide an error string from the ctr */ ++ char *error; ++}; ++ ++int dm_register_target(struct target_type *t); ++int dm_unregister_target(struct target_type *t); ++ ++#endif /* _LINUX_DEVICE_MAPPER_H */ +diff -ruN linux-2.4.20/include/linux/dm-ioctl.h linux/include/linux/dm-ioctl.h +--- linux-2.4.20/include/linux/dm-ioctl.h Thu Jan 1 01:00:00 1970 ++++ linux/include/linux/dm-ioctl.h Wed Mar 26 13:30:30 2003 +@@ -0,0 +1,149 @@ ++/* ++ * 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 ++ ++#define DM_DIR "mapper" /* Slashes not supported */ ++#define DM_MAX_TYPE_NAME 16 ++#define DM_NAME_LEN 128 ++#define DM_UUID_LEN 129 ++ ++/* ++ * 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 10 ++#define DM_VERSION_EXTRA "-ioctl (2003-03-26)" ++ ++/* 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-2.4.20/include/linux/fs.h linux/include/linux/fs.h +--- linux-2.4.20/include/linux/fs.h Fri Jan 10 16:35:55 2003 ++++ linux/include/linux/fs.h Wed Mar 26 12:53:19 2003 +@@ -220,6 +220,7 @@ + BH_Wait_IO, /* 1 if we should write out this buffer */ + BH_Launder, /* 1 if we can throttle on this buffer */ + BH_JBD, /* 1 if it has an attached journal_head */ ++ BH_Inode, /* 1 if it is attached to i_dirty[_data]_buffers */ + + BH_PrivateStart,/* not a state bit, but the first bit available + * for private allocation by other entities +@@ -262,11 +263,10 @@ + 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_journal_head; /* ext3 journal_heads */ + unsigned long b_rsector; /* Real buffer location on disk */ + wait_queue_head_t b_wait; + +- struct inode * b_inode; + struct list_head b_inode_buffers; /* doubly linked list of inode dirty buffers */ + }; + +@@ -1184,6 +1184,21 @@ + set_bit(BH_Async, &bh->b_state); + else + clear_bit(BH_Async, &bh->b_state); ++} ++ ++static inline void set_buffer_inode(struct buffer_head *bh) ++{ ++ set_bit(BH_Inode, &bh->b_state); ++} ++ ++static inline void clear_buffer_inode(struct buffer_head *bh) ++{ ++ clear_bit(BH_Inode, &bh->b_state); ++} ++ ++static inline int buffer_inode(struct buffer_head *bh) ++{ ++ return test_bit(BH_Inode, &bh->b_state); + } + + /* +diff -ruN linux-2.4.20/include/linux/jbd.h linux/include/linux/jbd.h +--- linux-2.4.20/include/linux/jbd.h Fri Jan 10 16:35:55 2003 ++++ linux/include/linux/jbd.h Wed Mar 26 12:53:19 2003 +@@ -254,7 +254,7 @@ + + static inline struct journal_head *bh2jh(struct buffer_head *bh) + { +- return bh->b_private; ++ return bh->b_journal_head; + } + + #define HAVE_JOURNAL_CALLBACK_STATUS +diff -ruN linux-2.4.20/include/linux/mempool.h linux/include/linux/mempool.h +--- linux-2.4.20/include/linux/mempool.h Thu Jan 1 01:00:00 1970 ++++ linux/include/linux/mempool.h Wed Mar 26 12:53:48 2003 +@@ -0,0 +1,31 @@ ++/* ++ * memory buffer pool support ++ */ ++#ifndef _LINUX_MEMPOOL_H ++#define _LINUX_MEMPOOL_H ++ ++#include ++#include ++ ++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); ++ ++extern mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn, ++ mempool_free_t *free_fn, void *pool_data); ++extern int 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-2.4.20/include/linux/vmalloc.h linux/include/linux/vmalloc.h +--- linux-2.4.20/include/linux/vmalloc.h Fri Jan 10 16:35:58 2003 ++++ linux/include/linux/vmalloc.h Wed Mar 26 12:53:19 2003 +@@ -26,6 +26,7 @@ + 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 +diff -ruN linux-2.4.20/kernel/ksyms.c linux/kernel/ksyms.c +--- linux-2.4.20/kernel/ksyms.c Fri Jan 10 16:36:02 2003 ++++ linux/kernel/ksyms.c Wed Mar 26 12:53:19 2003 +@@ -111,6 +111,7 @@ + EXPORT_SYMBOL(vfree); + EXPORT_SYMBOL(__vmalloc); + EXPORT_SYMBOL(vmalloc_to_page); ++EXPORT_SYMBOL(vcalloc); + EXPORT_SYMBOL(mem_map); + EXPORT_SYMBOL(remap_page_range); + EXPORT_SYMBOL(max_mapnr); +diff -ruN linux-2.4.20/mm/Makefile linux/mm/Makefile +--- linux-2.4.20/mm/Makefile Fri Jan 10 16:36:02 2003 ++++ linux/mm/Makefile Wed Mar 26 12:53:19 2003 +@@ -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-2.4.20/mm/mempool.c linux/mm/mempool.c +--- linux-2.4.20/mm/mempool.c Thu Jan 1 01:00:00 1970 ++++ linux/mm/mempool.c Wed Mar 26 12:53:48 2003 +@@ -0,0 +1,299 @@ ++/* ++ * 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 ++#include ++#include ++#include ++ ++struct mempool_s { ++ spinlock_t lock; ++ int min_nr; /* nr of elements at *elements */ ++ int curr_nr; /* Current nr of elements at *elements */ ++ void **elements; ++ ++ void *pool_data; ++ mempool_alloc_t *alloc; ++ mempool_free_t *free; ++ wait_queue_head_t wait; ++}; ++ ++static void add_element(mempool_t *pool, void *element) ++{ ++ BUG_ON(pool->curr_nr >= pool->min_nr); ++ pool->elements[pool->curr_nr++] = element; ++} ++ ++static void *remove_element(mempool_t *pool) ++{ ++ BUG_ON(pool->curr_nr <= 0); ++ return pool->elements[--pool->curr_nr]; ++} ++ ++static void free_pool(mempool_t *pool) ++{ ++ while (pool->curr_nr) { ++ void *element = remove_element(pool); ++ pool->free(element, pool->pool_data); ++ } ++ kfree(pool->elements); ++ kfree(pool); ++} ++ ++/** ++ * 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. ++ */ ++mempool_t * mempool_create(int min_nr, mempool_alloc_t *alloc_fn, ++ mempool_free_t *free_fn, void *pool_data) ++{ ++ mempool_t *pool; ++ ++ pool = kmalloc(sizeof(*pool), GFP_KERNEL); ++ if (!pool) ++ return NULL; ++ memset(pool, 0, sizeof(*pool)); ++ pool->elements = kmalloc(min_nr * sizeof(void *), GFP_KERNEL); ++ if (!pool->elements) { ++ kfree(pool); ++ return NULL; ++ } ++ spin_lock_init(&pool->lock); ++ pool->min_nr = min_nr; ++ pool->pool_data = pool_data; ++ init_waitqueue_head(&pool->wait); ++ pool->alloc = alloc_fn; ++ pool->free = free_fn; ++ ++ /* ++ * First pre-allocate the guaranteed number of buffers. ++ */ ++ while (pool->curr_nr < pool->min_nr) { ++ void *element; ++ ++ element = pool->alloc(GFP_KERNEL, pool->pool_data); ++ if (unlikely(!element)) { ++ free_pool(pool); ++ return NULL; ++ } ++ add_element(pool, element); ++ } ++ 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. ++ */ ++int mempool_resize(mempool_t *pool, int new_min_nr, int gfp_mask) ++{ ++ void *element; ++ void **new_elements; ++ unsigned long flags; ++ ++ BUG_ON(new_min_nr <= 0); ++ ++ spin_lock_irqsave(&pool->lock, flags); ++ if (new_min_nr < pool->min_nr) { ++ while (pool->curr_nr > new_min_nr) { ++ element = remove_element(pool); ++ spin_unlock_irqrestore(&pool->lock, flags); ++ pool->free(element, pool->pool_data); ++ spin_lock_irqsave(&pool->lock, flags); ++ } ++ pool->min_nr = new_min_nr; ++ goto out_unlock; ++ } ++ spin_unlock_irqrestore(&pool->lock, flags); ++ ++ /* Grow the pool */ ++ new_elements = kmalloc(new_min_nr * sizeof(*new_elements), gfp_mask); ++ if (!new_elements) ++ return -ENOMEM; ++ ++ spin_lock_irqsave(&pool->lock, flags); ++ memcpy(new_elements, pool->elements, ++ pool->curr_nr * sizeof(*new_elements)); ++ kfree(pool->elements); ++ pool->elements = new_elements; ++ pool->min_nr = new_min_nr; ++ ++ while (pool->curr_nr < pool->min_nr) { ++ spin_unlock_irqrestore(&pool->lock, flags); ++ element = pool->alloc(gfp_mask, pool->pool_data); ++ if (!element) ++ goto out; ++ spin_lock_irqsave(&pool->lock, flags); ++ if (pool->curr_nr < pool->min_nr) ++ add_element(pool, element); ++ else ++ kfree(element); /* Raced */ ++ } ++out_unlock: ++ spin_unlock_irqrestore(&pool->lock, flags); ++out: ++ return 0; ++} ++ ++/** ++ * 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 all elements have been returned to the pool (ie: ++ * freed) prior to calling mempool_destroy(). ++ */ ++void mempool_destroy(mempool_t *pool) ++{ ++ if (pool->curr_nr != pool->min_nr) ++ BUG(); /* There were outstanding elements */ ++ free_pool(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; ++ 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)) { ++ element = remove_element(pool); ++ 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) { ++ add_element(pool, element); ++ 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-2.4.20/mm/vmalloc.c linux/mm/vmalloc.c +--- linux-2.4.20/mm/vmalloc.c Fri Jan 10 16:36:03 2003 ++++ linux/mm/vmalloc.c Wed Mar 26 12:53:19 2003 +@@ -327,3 +327,22 @@ + 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; ++} -- 2.43.5