Merge git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild
authorLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 Jan 2008 11:46:14 +0000 (22:46 +1100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 29 Jan 2008 11:46:14 +0000 (22:46 +1100)
* git://git.kernel.org/pub/scm/linux/kernel/git/sam/kbuild: (79 commits)
  Remove references to "make dep"
  kconfig: document use of HAVE_*
  Introduce new section reference annotations tags: __ref, __refdata, __refconst
  kbuild: warn about ld added unique sections
  kbuild: add verbose option to Section mismatch reporting in modpost
  kconfig: tristate choices with mixed tristate and boolean values
  asm-generic/vmlix.lds.h: simplify __mem{init,exit}* dependencies
  remove __attribute_used__
  kbuild: support ARCH=x86 in buildtar
  kconfig: remove "enable"
  kbuild: simplified warning report in modpost
  kbuild: introduce a few helpers in modpost
  kbuild: use simpler section mismatch warnings in modpost
  kbuild: link vmlinux.o before kallsyms passes
  kbuild: introduce new option to enhance section mismatch analysis
  Use separate sections for __dev/__cpu/__mem code/data
  compiler.h: introduce __section()
  all archs: consolidate init and exit sections in vmlinux.lds.h
  kbuild: check section names consistently in modpost
  kbuild: introduce blacklisting in modpost
  ...

52 files changed:
Documentation/filesystems/ext4.txt
Documentation/filesystems/proc.txt
fs/Kconfig
fs/afs/dir.c
fs/afs/inode.c
fs/buffer.c
fs/ext2/super.c
fs/ext3/super.c
fs/ext4/Makefile
fs/ext4/balloc.c
fs/ext4/dir.c
fs/ext4/extents.c
fs/ext4/file.c
fs/ext4/group.h
fs/ext4/ialloc.c
fs/ext4/inode.c
fs/ext4/ioctl.c
fs/ext4/mballoc.c [new file with mode: 0644]
fs/ext4/migrate.c [new file with mode: 0644]
fs/ext4/namei.c
fs/ext4/resize.c
fs/ext4/super.c
fs/ext4/xattr.c
fs/inode.c
fs/jbd2/checkpoint.c
fs/jbd2/commit.c
fs/jbd2/journal.c
fs/jbd2/recovery.c
fs/jbd2/revoke.c
fs/jbd2/transaction.c
fs/ocfs2/cluster/sys.c
fs/read_write.c
include/asm-arm/bitops.h
include/asm-generic/bitops/ext2-non-atomic.h
include/asm-generic/bitops/le.h
include/asm-m68k/bitops.h
include/asm-m68knommu/bitops.h
include/asm-powerpc/bitops.h
include/asm-s390/bitops.h
include/linux/buffer_head.h
include/linux/ext4_fs.h
include/linux/ext4_fs_extents.h
include/linux/ext4_fs_i.h
include/linux/ext4_fs_sb.h
include/linux/fs.h
include/linux/jbd2.h
include/linux/module.h
kernel/extable.c
kernel/kallsyms.c
kernel/module.c
kernel/params.c
lib/find_next_bit.c

index 6a4adcae9f9a699d624a0bb114f8e0d5f86161c5..560f88dc7090dadcfd7c2db4fc6821c64b8da3fe 100644 (file)
@@ -86,9 +86,21 @@ Alex is working on a new set of patches right now.
 When mounting an ext4 filesystem, the following option are accepted:
 (*) == default
 
-extents                        ext4 will use extents to address file data.  The
+extents                (*)     ext4 will use extents to address file data.  The
                        file system will no longer be mountable by ext3.
 
+noextents              ext4 will not use extents for newly created files
+
+journal_checksum       Enable checksumming of the journal transactions.
+                       This will allow the recovery code in e2fsck and the
+                       kernel to detect corruption in the kernel.  It is a
+                       compatible change and will be ignored by older kernels.
+
+journal_async_commit   Commit block can be written to disk without waiting
+                       for descriptor blocks. If enabled older kernels cannot
+                       mount the device. This will enable 'journal_checksum'
+                       internally.
+
 journal=update         Update the ext4 file system's journal to the current
                        format.
 
@@ -196,6 +208,12 @@ nobh                       (a) cache disk block mapping information
                        "nobh" option tries to avoid associating buffer
                        heads (supported only for "writeback" mode).
 
+mballoc                (*)     Use the multiple block allocator for block allocation
+nomballoc              disabled multiple block allocator for block allocation.
+stripe=n               Number of filesystem blocks that mballoc will try
+                       to use for allocation size and alignment. For RAID5/6
+                       systems this should be the number of data
+                       disks *  RAID chunk size in file system blocks.
 
 Data Mode
 ---------
index dec99455321fdf86018ca5b2b62936103fd73031..4413a2d4646fc4fd5305cb60e06a57bd5243bd16 100644 (file)
@@ -857,6 +857,45 @@ CPUs.
 The   "procs_blocked" line gives  the  number of  processes currently blocked,
 waiting for I/O to complete.
 
+1.9 Ext4 file system parameters
+------------------------------
+Ext4 file system have one directory per partition under /proc/fs/ext4/
+# ls /proc/fs/ext4/hdc/
+group_prealloc  max_to_scan  mb_groups  mb_history  min_to_scan  order2_req
+stats  stream_req
+
+mb_groups:
+This file gives the details of mutiblock allocator buddy cache of free blocks
+
+mb_history:
+Multiblock allocation history.
+
+stats:
+This file indicate whether the multiblock allocator should start collecting
+statistics. The statistics are shown during unmount
+
+group_prealloc:
+The multiblock allocator normalize the block allocation request to
+group_prealloc filesystem blocks if we don't have strip value set.
+The stripe value can be specified at mount time or during mke2fs.
+
+max_to_scan:
+How long multiblock allocator can look for a best extent (in found extents)
+
+min_to_scan:
+How long multiblock allocator  must look for a best extent
+
+order2_req:
+Multiblock allocator use  2^N search using buddies only for requests greater
+than or equal to order2_req. The request size is specfied in file system
+blocks. A value of 2 indicate only if the requests are greater than or equal
+to 4 blocks.
+
+stream_req:
+Files smaller than stream_req are served by the stream allocator, whose
+purpose is to pack requests as close each to other as possible to
+produce smooth I/O traffic. Avalue of 16 indicate that file smaller than 16
+filesystem block size will use group based preallocation.
 
 ------------------------------------------------------------------------------
 Summary
index 9656139d2e990ce8c11e6ed34a2b61182da332ff..219ec06a8c7e2cd057a28898c4827776a1abf0c3 100644 (file)
@@ -236,6 +236,7 @@ config JBD_DEBUG
 
 config JBD2
        tristate
+       select CRC32
        help
          This is a generic journaling layer for block devices that support
          both 32-bit and 64-bit block numbers.  It is currently used by
index 33fe39ad4e0327a91e925c10ad54629c5f7c763a..0cc3597c11971380716d10083eee9fa7660f82dd 100644 (file)
@@ -546,11 +546,11 @@ static struct dentry *afs_lookup(struct inode *dir, struct dentry *dentry,
        dentry->d_op = &afs_fs_dentry_operations;
 
        d_add(dentry, inode);
-       _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%lu }",
+       _leave(" = 0 { vn=%u u=%u } -> { ino=%lu v=%llu }",
               fid.vnode,
               fid.unique,
               dentry->d_inode->i_ino,
-              dentry->d_inode->i_version);
+              (unsigned long long)dentry->d_inode->i_version);
 
        return NULL;
 }
@@ -630,9 +630,10 @@ static int afs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
                 * been deleted and replaced, and the original vnode ID has
                 * been reused */
                if (fid.unique != vnode->fid.unique) {
-                       _debug("%s: file deleted (uq %u -> %u I:%lu)",
+                       _debug("%s: file deleted (uq %u -> %u I:%llu)",
                               dentry->d_name.name, fid.unique,
-                              vnode->fid.unique, dentry->d_inode->i_version);
+                              vnode->fid.unique,
+                              (unsigned long long)dentry->d_inode->i_version);
                        spin_lock(&vnode->lock);
                        set_bit(AFS_VNODE_DELETED, &vnode->flags);
                        spin_unlock(&vnode->lock);
index d196840127c6bdf7174defa94fc7184c25e2ad92..84750c8e9f95be1b07ba30ed7ab4778cf1ae9599 100644 (file)
@@ -301,7 +301,8 @@ int afs_getattr(struct vfsmount *mnt, struct dentry *dentry,
 
        inode = dentry->d_inode;
 
-       _enter("{ ino=%lu v=%lu }", inode->i_ino, inode->i_version);
+       _enter("{ ino=%lu v=%llu }", inode->i_ino,
+               (unsigned long long)inode->i_version);
 
        generic_fillattr(inode, stat);
        return 0;
index 7249e014819e1a0432621d1d2576fd259f27632d..456c9ab7705b0fce1f7299ee455c26614330fb34 100644 (file)
@@ -3213,6 +3213,50 @@ static int buffer_cpu_notify(struct notifier_block *self,
        return NOTIFY_OK;
 }
 
+/**
+ * bh_uptodate_or_lock: Test whether the buffer is uptodate
+ * @bh: struct buffer_head
+ *
+ * Return true if the buffer is up-to-date and false,
+ * with the buffer locked, if not.
+ */
+int bh_uptodate_or_lock(struct buffer_head *bh)
+{
+       if (!buffer_uptodate(bh)) {
+               lock_buffer(bh);
+               if (!buffer_uptodate(bh))
+                       return 0;
+               unlock_buffer(bh);
+       }
+       return 1;
+}
+EXPORT_SYMBOL(bh_uptodate_or_lock);
+
+/**
+ * bh_submit_read: Submit a locked buffer for reading
+ * @bh: struct buffer_head
+ *
+ * Returns zero on success and -EIO on error.
+ */
+int bh_submit_read(struct buffer_head *bh)
+{
+       BUG_ON(!buffer_locked(bh));
+
+       if (buffer_uptodate(bh)) {
+               unlock_buffer(bh);
+               return 0;
+       }
+
+       get_bh(bh);
+       bh->b_end_io = end_buffer_read_sync;
+       submit_bh(READ, bh);
+       wait_on_buffer(bh);
+       if (buffer_uptodate(bh))
+               return 0;
+       return -EIO;
+}
+EXPORT_SYMBOL(bh_submit_read);
+
 void __init buffer_init(void)
 {
        int nrpages;
index 154e25f13d772235e7c7d242a0b5e6fdbf977cd7..6abaf75163f0b17b1cbfb9b8b6e7ad563930bfdc 100644 (file)
@@ -680,11 +680,31 @@ static int ext2_check_descriptors (struct super_block * sb)
 static loff_t ext2_max_size(int bits)
 {
        loff_t res = EXT2_NDIR_BLOCKS;
-       /* This constant is calculated to be the largest file size for a
-        * dense, 4k-blocksize file such that the total number of
+       int meta_blocks;
+       loff_t upper_limit;
+
+       /* This is calculated to be the largest file size for a
+        * dense, file such that the total number of
         * sectors in the file, including data and all indirect blocks,
-        * does not exceed 2^32. */
-       const loff_t upper_limit = 0x1ff7fffd000LL;
+        * does not exceed 2^32 -1
+        * __u32 i_blocks representing the total number of
+        * 512 bytes blocks of the file
+        */
+       upper_limit = (1LL << 32) - 1;
+
+       /* total blocks in file system block size */
+       upper_limit >>= (bits - 9);
+
+
+       /* indirect blocks */
+       meta_blocks = 1;
+       /* double indirect blocks */
+       meta_blocks += 1 + (1LL << (bits-2));
+       /* tripple indirect blocks */
+       meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
+
+       upper_limit -= meta_blocks;
+       upper_limit <<= bits;
 
        res += 1LL << (bits-2);
        res += 1LL << (2*(bits-2));
@@ -692,6 +712,10 @@ static loff_t ext2_max_size(int bits)
        res <<= bits;
        if (res > upper_limit)
                res = upper_limit;
+
+       if (res > MAX_LFS_FILESIZE)
+               res = MAX_LFS_FILESIZE;
+
        return res;
 }
 
index cb14de1502c35783fd89d11f4b362cd28faaf91c..f3675cc630e97a7c5ab42251193050872957c5c1 100644 (file)
@@ -1436,11 +1436,31 @@ static void ext3_orphan_cleanup (struct super_block * sb,
 static loff_t ext3_max_size(int bits)
 {
        loff_t res = EXT3_NDIR_BLOCKS;
-       /* This constant is calculated to be the largest file size for a
-        * dense, 4k-blocksize file such that the total number of
+       int meta_blocks;
+       loff_t upper_limit;
+
+       /* This is calculated to be the largest file size for a
+        * dense, file such that the total number of
         * sectors in the file, including data and all indirect blocks,
-        * does not exceed 2^32. */
-       const loff_t upper_limit = 0x1ff7fffd000LL;
+        * does not exceed 2^32 -1
+        * __u32 i_blocks representing the total number of
+        * 512 bytes blocks of the file
+        */
+       upper_limit = (1LL << 32) - 1;
+
+       /* total blocks in file system block size */
+       upper_limit >>= (bits - 9);
+
+
+       /* indirect blocks */
+       meta_blocks = 1;
+       /* double indirect blocks */
+       meta_blocks += 1 + (1LL << (bits-2));
+       /* tripple indirect blocks */
+       meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
+
+       upper_limit -= meta_blocks;
+       upper_limit <<= bits;
 
        res += 1LL << (bits-2);
        res += 1LL << (2*(bits-2));
@@ -1448,6 +1468,10 @@ static loff_t ext3_max_size(int bits)
        res <<= bits;
        if (res > upper_limit)
                res = upper_limit;
+
+       if (res > MAX_LFS_FILESIZE)
+               res = MAX_LFS_FILESIZE;
+
        return res;
 }
 
index ae6e7e502ac9c0d5585370ba0c051410ab766ad8..ac6fa8ca0a2f1b7b3a99f03accce58f6f666e209 100644 (file)
@@ -6,7 +6,7 @@ obj-$(CONFIG_EXT4DEV_FS) += ext4dev.o
 
 ext4dev-y      := balloc.o bitmap.o dir.o file.o fsync.o ialloc.o inode.o \
                   ioctl.o namei.o super.o symlink.o hash.o resize.o extents.o \
-                  ext4_jbd2.o
+                  ext4_jbd2.o migrate.o mballoc.o
 
 ext4dev-$(CONFIG_EXT4DEV_FS_XATTR)     += xattr.o xattr_user.o xattr_trusted.o
 ext4dev-$(CONFIG_EXT4DEV_FS_POSIX_ACL) += acl.o
index 71ee95e534fdcb6c7128aa843accea7b9a082eec..ac75ea953d83fbfe3d3919783f85c963d905c264 100644 (file)
@@ -29,7 +29,7 @@
  * Calculate the block group number and offset, given a block number
  */
 void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
-               unsigned long *blockgrpp, ext4_grpblk_t *offsetp)
+               ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
 {
        struct ext4_super_block *es = EXT4_SB(sb)->s_es;
        ext4_grpblk_t offset;
@@ -46,7 +46,7 @@ void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
 /* Initializes an uninitialized block bitmap if given, and returns the
  * number of blocks free in the group. */
 unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
-                               int block_group, struct ext4_group_desc *gdp)
+                ext4_group_t block_group, struct ext4_group_desc *gdp)
 {
        unsigned long start;
        int bit, bit_max;
@@ -60,7 +60,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
                 * essentially implementing a per-group read-only flag. */
                if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
                        ext4_error(sb, __FUNCTION__,
-                                  "Checksum bad for group %u\n", block_group);
+                                 "Checksum bad for group %lu\n", block_group);
                        gdp->bg_free_blocks_count = 0;
                        gdp->bg_free_inodes_count = 0;
                        gdp->bg_itable_unused = 0;
@@ -153,7 +153,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh,
  *                     group descriptor
  */
 struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
-                                            unsigned int block_group,
+                                            ext4_group_t block_group,
                                             struct buffer_head ** bh)
 {
        unsigned long group_desc;
@@ -164,7 +164,7 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
        if (block_group >= sbi->s_groups_count) {
                ext4_error (sb, "ext4_get_group_desc",
                            "block_group >= groups_count - "
-                           "block_group = %d, groups_count = %lu",
+                           "block_group = %lu, groups_count = %lu",
                            block_group, sbi->s_groups_count);
 
                return NULL;
@@ -176,7 +176,7 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
        if (!sbi->s_group_desc[group_desc]) {
                ext4_error (sb, "ext4_get_group_desc",
                            "Group descriptor not loaded - "
-                           "block_group = %d, group_desc = %lu, desc = %lu",
+                           "block_group = %lu, group_desc = %lu, desc = %lu",
                             block_group, group_desc, offset);
                return NULL;
        }
@@ -189,18 +189,70 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,
        return desc;
 }
 
+static int ext4_valid_block_bitmap(struct super_block *sb,
+                                       struct ext4_group_desc *desc,
+                                       unsigned int block_group,
+                                       struct buffer_head *bh)
+{
+       ext4_grpblk_t offset;
+       ext4_grpblk_t next_zero_bit;
+       ext4_fsblk_t bitmap_blk;
+       ext4_fsblk_t group_first_block;
+
+       if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
+               /* with FLEX_BG, the inode/block bitmaps and itable
+                * blocks may not be in the group at all
+                * so the bitmap validation will be skipped for those groups
+                * or it has to also read the block group where the bitmaps
+                * are located to verify they are set.
+                */
+               return 1;
+       }
+       group_first_block = ext4_group_first_block_no(sb, block_group);
+
+       /* check whether block bitmap block number is set */
+       bitmap_blk = ext4_block_bitmap(sb, desc);
+       offset = bitmap_blk - group_first_block;
+       if (!ext4_test_bit(offset, bh->b_data))
+               /* bad block bitmap */
+               goto err_out;
+
+       /* check whether the inode bitmap block number is set */
+       bitmap_blk = ext4_inode_bitmap(sb, desc);
+       offset = bitmap_blk - group_first_block;
+       if (!ext4_test_bit(offset, bh->b_data))
+               /* bad block bitmap */
+               goto err_out;
+
+       /* check whether the inode table block number is set */
+       bitmap_blk = ext4_inode_table(sb, desc);
+       offset = bitmap_blk - group_first_block;
+       next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
+                               offset + EXT4_SB(sb)->s_itb_per_group,
+                               offset);
+       if (next_zero_bit >= offset + EXT4_SB(sb)->s_itb_per_group)
+               /* good bitmap for inode tables */
+               return 1;
+
+err_out:
+       ext4_error(sb, __FUNCTION__,
+                       "Invalid block bitmap - "
+                       "block_group = %d, block = %llu",
+                       block_group, bitmap_blk);
+       return 0;
+}
 /**
  * read_block_bitmap()
  * @sb:                        super block
  * @block_group:       given block group
  *
- * Read the bitmap for a given block_group, reading into the specified
- * slot in the superblock's bitmap cache.
+ * Read the bitmap for a given block_group,and validate the
+ * bits for block/inode/inode tables are set in the bitmaps
  *
  * Return buffer_head on success or NULL in case of failure.
  */
 struct buffer_head *
-read_block_bitmap(struct super_block *sb, unsigned int block_group)
+read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
 {
        struct ext4_group_desc * desc;
        struct buffer_head * bh = NULL;
@@ -210,25 +262,36 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
        if (!desc)
                return NULL;
        bitmap_blk = ext4_block_bitmap(sb, desc);
+       bh = sb_getblk(sb, bitmap_blk);
+       if (unlikely(!bh)) {
+               ext4_error(sb, __FUNCTION__,
+                           "Cannot read block bitmap - "
+                           "block_group = %d, block_bitmap = %llu",
+                           (int)block_group, (unsigned long long)bitmap_blk);
+               return NULL;
+       }
+       if (bh_uptodate_or_lock(bh))
+               return bh;
+
        if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
-               bh = sb_getblk(sb, bitmap_blk);
-               if (!buffer_uptodate(bh)) {
-                       lock_buffer(bh);
-                       if (!buffer_uptodate(bh)) {
-                               ext4_init_block_bitmap(sb, bh, block_group,
-                                                      desc);
-                               set_buffer_uptodate(bh);
-                       }
-                       unlock_buffer(bh);
-               }
-       } else {
-               bh = sb_bread(sb, bitmap_blk);
+               ext4_init_block_bitmap(sb, bh, block_group, desc);
+               set_buffer_uptodate(bh);
+               unlock_buffer(bh);
+               return bh;
        }
-       if (!bh)
-               ext4_error (sb, __FUNCTION__,
+       if (bh_submit_read(bh) < 0) {
+               put_bh(bh);
+               ext4_error(sb, __FUNCTION__,
                            "Cannot read block bitmap - "
                            "block_group = %d, block_bitmap = %llu",
-                           block_group, bitmap_blk);
+                           (int)block_group, (unsigned long long)bitmap_blk);
+               return NULL;
+       }
+       if (!ext4_valid_block_bitmap(sb, desc, block_group, bh)) {
+               put_bh(bh);
+               return NULL;
+       }
+
        return bh;
 }
 /*
@@ -320,7 +383,7 @@ restart:
  */
 static int
 goal_in_my_reservation(struct ext4_reserve_window *rsv, ext4_grpblk_t grp_goal,
-                       unsigned int group, struct super_block * sb)
+                       ext4_group_t group, struct super_block *sb)
 {
        ext4_fsblk_t group_first_block, group_last_block;
 
@@ -463,7 +526,7 @@ static inline int rsv_is_empty(struct ext4_reserve_window *rsv)
  * when setting the reservation window size through ioctl before the file
  * is open for write (needs block allocation).
  *
- * Needs truncate_mutex protection prior to call this function.
+ * Needs down_write(i_data_sem) protection prior to call this function.
  */
 void ext4_init_block_alloc_info(struct inode *inode)
 {
@@ -514,6 +577,8 @@ void ext4_discard_reservation(struct inode *inode)
        struct ext4_reserve_window_node *rsv;
        spinlock_t *rsv_lock = &EXT4_SB(inode->i_sb)->s_rsv_window_lock;
 
+       ext4_mb_discard_inode_preallocations(inode);
+
        if (!block_i)
                return;
 
@@ -540,7 +605,7 @@ void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb,
 {
        struct buffer_head *bitmap_bh = NULL;
        struct buffer_head *gd_bh;
-       unsigned long block_group;
+       ext4_group_t block_group;
        ext4_grpblk_t bit;
        unsigned long i;
        unsigned long overflow;
@@ -587,11 +652,13 @@ do_more:
            in_range(ext4_inode_bitmap(sb, desc), block, count) ||
            in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
            in_range(block + count - 1, ext4_inode_table(sb, desc),
-                    sbi->s_itb_per_group))
+                    sbi->s_itb_per_group)) {
                ext4_error (sb, "ext4_free_blocks",
                            "Freeing blocks in system zones - "
                            "Block = %llu, count = %lu",
                            block, count);
+               goto error_return;
+       }
 
        /*
         * We are about to start releasing blocks in the bitmap,
@@ -720,19 +787,29 @@ error_return:
  * @inode:             inode
  * @block:             start physical block to free
  * @count:             number of blocks to count
+ * @metadata:          Are these metadata blocks
  */
 void ext4_free_blocks(handle_t *handle, struct inode *inode,
-                       ext4_fsblk_t block, unsigned long count)
+                       ext4_fsblk_t block, unsigned long count,
+                       int metadata)
 {
        struct super_block * sb;
        unsigned long dquot_freed_blocks;
 
+       /* this isn't the right place to decide whether block is metadata
+        * inode.c/extents.c knows better, but for safety ... */
+       if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
+                       ext4_should_journal_data(inode))
+               metadata = 1;
+
        sb = inode->i_sb;
-       if (!sb) {
-               printk ("ext4_free_blocks: nonexistent device");
-               return;
-       }
-       ext4_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks);
+
+       if (!test_opt(sb, MBALLOC) || !EXT4_SB(sb)->s_group_info)
+               ext4_free_blocks_sb(handle, sb, block, count,
+                                               &dquot_freed_blocks);
+       else
+               ext4_mb_free_blocks(handle, inode, block, count,
+                                               metadata, &dquot_freed_blocks);
        if (dquot_freed_blocks)
                DQUOT_FREE_BLOCK(inode, dquot_freed_blocks);
        return;
@@ -920,9 +997,10 @@ claim_block(spinlock_t *lock, ext4_grpblk_t block, struct buffer_head *bh)
  * ext4_journal_release_buffer(), else we'll run out of credits.
  */
 static ext4_grpblk_t
-ext4_try_to_allocate(struct super_block *sb, handle_t *handle, int group,
-                       struct buffer_head *bitmap_bh, ext4_grpblk_t grp_goal,
-                       unsigned long *count, struct ext4_reserve_window *my_rsv)
+ext4_try_to_allocate(struct super_block *sb, handle_t *handle,
+                       ext4_group_t group, struct buffer_head *bitmap_bh,
+                       ext4_grpblk_t grp_goal, unsigned long *count,
+                       struct ext4_reserve_window *my_rsv)
 {
        ext4_fsblk_t group_first_block;
        ext4_grpblk_t start, end;
@@ -1156,7 +1234,7 @@ static int find_next_reservable_window(
  */
 static int alloc_new_reservation(struct ext4_reserve_window_node *my_rsv,
                ext4_grpblk_t grp_goal, struct super_block *sb,
-               unsigned int group, struct buffer_head *bitmap_bh)
+               ext4_group_t group, struct buffer_head *bitmap_bh)
 {
        struct ext4_reserve_window_node *search_head;
        ext4_fsblk_t group_first_block, group_end_block, start_block;
@@ -1354,7 +1432,7 @@ static void try_to_extend_reservation(struct ext4_reserve_window_node *my_rsv,
  */
 static ext4_grpblk_t
 ext4_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
-                       unsigned int group, struct buffer_head *bitmap_bh,
+                       ext4_group_t group, struct buffer_head *bitmap_bh,
                        ext4_grpblk_t grp_goal,
                        struct ext4_reserve_window_node * my_rsv,
                        unsigned long *count, int *errp)
@@ -1510,7 +1588,7 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
 }
 
 /**
- * ext4_new_blocks() -- core block(s) allocation function
+ * ext4_new_blocks_old() -- core block(s) allocation function
  * @handle:            handle to this transaction
  * @inode:             file inode
  * @goal:              given target block(filesystem wide)
@@ -1523,17 +1601,17 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
  * any specific goal block.
  *
  */
-ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
                        ext4_fsblk_t goal, unsigned long *count, int *errp)
 {
        struct buffer_head *bitmap_bh = NULL;
        struct buffer_head *gdp_bh;
-       unsigned long group_no;
-       int goal_group;
+       ext4_group_t group_no;
+       ext4_group_t goal_group;
        ext4_grpblk_t grp_target_blk;   /* blockgroup relative goal block */
        ext4_grpblk_t grp_alloc_blk;    /* blockgroup-relative allocated block*/
        ext4_fsblk_t ret_block;         /* filesyetem-wide allocated block */
-       int bgi;                        /* blockgroup iteration index */
+       ext4_group_t bgi;                       /* blockgroup iteration index */
        int fatal = 0, err;
        int performed_allocation = 0;
        ext4_grpblk_t free_blocks;      /* number of free blocks in a group */
@@ -1544,10 +1622,7 @@ ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
        struct ext4_reserve_window_node *my_rsv = NULL;
        struct ext4_block_alloc_info *block_i;
        unsigned short windowsz = 0;
-#ifdef EXT4FS_DEBUG
-       static int goal_hits, goal_attempts;
-#endif
-       unsigned long ngroups;
+       ext4_group_t ngroups;
        unsigned long num = *count;
 
        *errp = -ENOSPC;
@@ -1567,7 +1642,7 @@ ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
 
        sbi = EXT4_SB(sb);
        es = EXT4_SB(sb)->s_es;
-       ext4_debug("goal=%lu.\n", goal);
+       ext4_debug("goal=%llu.\n", goal);
        /*
         * Allocate a block from reservation only when
         * filesystem is mounted with reservation(default,-o reservation), and
@@ -1677,7 +1752,7 @@ retry_alloc:
 
 allocated:
 
-       ext4_debug("using block group %d(%d)\n",
+       ext4_debug("using block group %lu(%d)\n",
                        group_no, gdp->bg_free_blocks_count);
 
        BUFFER_TRACE(gdp_bh, "get_write_access");
@@ -1692,11 +1767,13 @@ allocated:
            in_range(ret_block, ext4_inode_table(sb, gdp),
                     EXT4_SB(sb)->s_itb_per_group) ||
            in_range(ret_block + num - 1, ext4_inode_table(sb, gdp),
-                    EXT4_SB(sb)->s_itb_per_group))
+                    EXT4_SB(sb)->s_itb_per_group)) {
                ext4_error(sb, "ext4_new_block",
                            "Allocating block in system zone - "
                            "blocks from %llu, length %lu",
                             ret_block, num);
+               goto out;
+       }
 
        performed_allocation = 1;
 
@@ -1743,9 +1820,6 @@ allocated:
         * list of some description.  We don't know in advance whether
         * the caller wants to use it as metadata or data.
         */
-       ext4_debug("allocating block %lu. Goal hits %d of %d.\n",
-                       ret_block, goal_hits, goal_attempts);
-
        spin_lock(sb_bgl_lock(sbi, group_no));
        if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
                gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
@@ -1787,13 +1861,46 @@ out:
 }
 
 ext4_fsblk_t ext4_new_block(handle_t *handle, struct inode *inode,
-                       ext4_fsblk_t goal, int *errp)
+               ext4_fsblk_t goal, int *errp)
 {
-       unsigned long count = 1;
+       struct ext4_allocation_request ar;
+       ext4_fsblk_t ret;
 
-       return ext4_new_blocks(handle, inode, goal, &count, errp);
+       if (!test_opt(inode->i_sb, MBALLOC)) {
+               unsigned long count = 1;
+               ret = ext4_new_blocks_old(handle, inode, goal, &count, errp);
+               return ret;
+       }
+
+       memset(&ar, 0, sizeof(ar));
+       ar.inode = inode;
+       ar.goal = goal;
+       ar.len = 1;
+       ret = ext4_mb_new_blocks(handle, &ar, errp);
+       return ret;
+}
+
+ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
+               ext4_fsblk_t goal, unsigned long *count, int *errp)
+{
+       struct ext4_allocation_request ar;
+       ext4_fsblk_t ret;
+
+       if (!test_opt(inode->i_sb, MBALLOC)) {
+               ret = ext4_new_blocks_old(handle, inode, goal, count, errp);
+               return ret;
+       }
+
+       memset(&ar, 0, sizeof(ar));
+       ar.inode = inode;
+       ar.goal = goal;
+       ar.len = *count;
+       ret = ext4_mb_new_blocks(handle, &ar, errp);
+       *count = ar.len;
+       return ret;
 }
 
+
 /**
  * ext4_count_free_blocks() -- count filesystem free blocks
  * @sb:                superblock
@@ -1804,8 +1911,8 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
 {
        ext4_fsblk_t desc_count;
        struct ext4_group_desc *gdp;
-       int i;
-       unsigned long ngroups = EXT4_SB(sb)->s_groups_count;
+       ext4_group_t i;
+       ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
 #ifdef EXT4FS_DEBUG
        struct ext4_super_block *es;
        ext4_fsblk_t bitmap_count;
@@ -1829,14 +1936,14 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
                        continue;
 
                x = ext4_count_free(bitmap_bh, sb->s_blocksize);
-               printk("group %d: stored = %d, counted = %lu\n",
+               printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
                        i, le16_to_cpu(gdp->bg_free_blocks_count), x);
                bitmap_count += x;
        }
        brelse(bitmap_bh);
        printk("ext4_count_free_blocks: stored = %llu"
                ", computed = %llu, %llu\n",
-              EXT4_FREE_BLOCKS_COUNT(es),
+               ext4_free_blocks_count(es),
                desc_count, bitmap_count);
        return bitmap_count;
 #else
@@ -1853,7 +1960,7 @@ ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb)
 #endif
 }
 
-static inline int test_root(int a, int b)
+static inline int test_root(ext4_group_t a, int b)
 {
        int num = b;
 
@@ -1862,7 +1969,7 @@ static inline int test_root(int a, int b)
        return num == a;
 }
 
-static int ext4_group_sparse(int group)
+static int ext4_group_sparse(ext4_group_t group)
 {
        if (group <= 1)
                return 1;
@@ -1880,7 +1987,7 @@ static int ext4_group_sparse(int group)
  *     Return the number of blocks used by the superblock (primary or backup)
  *     in this group.  Currently this will be only 0 or 1.
  */
-int ext4_bg_has_super(struct super_block *sb, int group)
+int ext4_bg_has_super(struct super_block *sb, ext4_group_t group)
 {
        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
                                EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
@@ -1889,18 +1996,20 @@ int ext4_bg_has_super(struct super_block *sb, int group)
        return 1;
 }
 
-static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb, int group)
+static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
+                                       ext4_group_t group)
 {
        unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
-       unsigned long first = metagroup * EXT4_DESC_PER_BLOCK(sb);
-       unsigned long last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
+       ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb);
+       ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
 
        if (group == first || group == first + 1 || group == last)
                return 1;
        return 0;
 }
 
-static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, int group)
+static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
+                                       ext4_group_t group)
 {
        if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
                                EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) &&
@@ -1918,7 +2027,7 @@ static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, int group)
  *     (primary or backup) in this group.  In the future there may be a
  *     different number of descriptor blocks in each group.
  */
-unsigned long ext4_bg_num_gdb(struct super_block *sb, int group)
+unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
 {
        unsigned long first_meta_bg =
                        le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
index f612bef983158f4a82c3d2a4b1211a94e713019a..33888bb58144fc1660d4106dbcbd689b560d2aa0 100644 (file)
@@ -67,7 +67,7 @@ int ext4_check_dir_entry (const char * function, struct inode * dir,
                          unsigned long offset)
 {
        const char * error_msg = NULL;
-       const int rlen = le16_to_cpu(de->rec_len);
+       const int rlen = ext4_rec_len_from_disk(de->rec_len);
 
        if (rlen < EXT4_DIR_REC_LEN(1))
                error_msg = "rec_len is smaller than minimal";
@@ -124,7 +124,7 @@ static int ext4_readdir(struct file * filp,
        offset = filp->f_pos & (sb->s_blocksize - 1);
 
        while (!error && !stored && filp->f_pos < inode->i_size) {
-               unsigned long blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
+               ext4_lblk_t blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb);
                struct buffer_head map_bh;
                struct buffer_head *bh = NULL;
 
@@ -172,10 +172,10 @@ revalidate:
                                 * least that it is non-zero.  A
                                 * failure will be detected in the
                                 * dirent test below. */
-                               if (le16_to_cpu(de->rec_len) <
-                                               EXT4_DIR_REC_LEN(1))
+                               if (ext4_rec_len_from_disk(de->rec_len)
+                                               EXT4_DIR_REC_LEN(1))
                                        break;
-                               i += le16_to_cpu(de->rec_len);
+                               i += ext4_rec_len_from_disk(de->rec_len);
                        }
                        offset = i;
                        filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
@@ -197,7 +197,7 @@ revalidate:
                                ret = stored;
                                goto out;
                        }
-                       offset += le16_to_cpu(de->rec_len);
+                       offset += ext4_rec_len_from_disk(de->rec_len);
                        if (le32_to_cpu(de->inode)) {
                                /* We might block in the next section
                                 * if the data destination is
@@ -219,7 +219,7 @@ revalidate:
                                        goto revalidate;
                                stored ++;
                        }
-                       filp->f_pos += le16_to_cpu(de->rec_len);
+                       filp->f_pos += ext4_rec_len_from_disk(de->rec_len);
                }
                offset = 0;
                brelse (bh);
index 85287742f2ae487562be3a8ac39e40774a5de9d3..bc7081f1fbe80dd5add381c5746b1bbc74e4883a 100644 (file)
@@ -61,7 +61,7 @@ static ext4_fsblk_t ext_pblock(struct ext4_extent *ex)
  * idx_pblock:
  * combine low and high parts of a leaf physical block number into ext4_fsblk_t
  */
-static ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
+ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
 {
        ext4_fsblk_t block;
 
@@ -75,7 +75,7 @@ static ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix)
  * stores a large physical block number into an extent struct,
  * breaking it into parts
  */
-static void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
+void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb)
 {
        ex->ee_start_lo = cpu_to_le32((unsigned long) (pb & 0xffffffff));
        ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff);
@@ -144,7 +144,7 @@ static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
 
 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
                              struct ext4_ext_path *path,
-                             ext4_fsblk_t block)
+                             ext4_lblk_t block)
 {
        struct ext4_inode_info *ei = EXT4_I(inode);
        ext4_fsblk_t bg_start;
@@ -367,13 +367,14 @@ static void ext4_ext_drop_refs(struct ext4_ext_path *path)
  * the header must be checked before calling this
  */
 static void
-ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block)
+ext4_ext_binsearch_idx(struct inode *inode,
+                       struct ext4_ext_path *path, ext4_lblk_t block)
 {
        struct ext4_extent_header *eh = path->p_hdr;
        struct ext4_extent_idx *r, *l, *m;
 
 
-       ext_debug("binsearch for %d(idx):  ", block);
+       ext_debug("binsearch for %u(idx):  ", block);
 
        l = EXT_FIRST_INDEX(eh) + 1;
        r = EXT_LAST_INDEX(eh);
@@ -425,7 +426,8 @@ ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int bloc
  * the header must be checked before calling this
  */
 static void
-ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
+ext4_ext_binsearch(struct inode *inode,
+               struct ext4_ext_path *path, ext4_lblk_t block)
 {
        struct ext4_extent_header *eh = path->p_hdr;
        struct ext4_extent *r, *l, *m;
@@ -438,7 +440,7 @@ ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block)
                return;
        }
 
-       ext_debug("binsearch for %d:  ", block);
+       ext_debug("binsearch for %u:  ", block);
 
        l = EXT_FIRST_EXTENT(eh) + 1;
        r = EXT_LAST_EXTENT(eh);
@@ -494,7 +496,8 @@ int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
 }
 
 struct ext4_ext_path *
-ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path)
+ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
+                                       struct ext4_ext_path *path)
 {
        struct ext4_extent_header *eh;
        struct buffer_head *bh;
@@ -763,7 +766,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
        while (k--) {
                oldblock = newblock;
                newblock = ablocks[--a];
-               bh = sb_getblk(inode->i_sb, (ext4_fsblk_t)newblock);
+               bh = sb_getblk(inode->i_sb, newblock);
                if (!bh) {
                        err = -EIO;
                        goto cleanup;
@@ -783,9 +786,8 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
                fidx->ei_block = border;
                ext4_idx_store_pblock(fidx, oldblock);
 
-               ext_debug("int.index at %d (block %llu): %lu -> %llu\n", i,
-                               newblock, (unsigned long) le32_to_cpu(border),
-                               oldblock);
+               ext_debug("int.index at %d (block %llu): %u -> %llu\n",
+                               i, newblock, le32_to_cpu(border), oldblock);
                /* copy indexes */
                m = 0;
                path[i].p_idx++;
@@ -851,7 +853,7 @@ cleanup:
                for (i = 0; i < depth; i++) {
                        if (!ablocks[i])
                                continue;
-                       ext4_free_blocks(handle, inode, ablocks[i], 1);
+                       ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
                }
        }
        kfree(ablocks);
@@ -979,8 +981,8 @@ repeat:
                /* refill path */
                ext4_ext_drop_refs(path);
                path = ext4_ext_find_extent(inode,
-                                           le32_to_cpu(newext->ee_block),
-                                           path);
+                                   (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+                                   path);
                if (IS_ERR(path))
                        err = PTR_ERR(path);
        } else {
@@ -992,8 +994,8 @@ repeat:
                /* refill path */
                ext4_ext_drop_refs(path);
                path = ext4_ext_find_extent(inode,
-                                           le32_to_cpu(newext->ee_block),
-                                           path);
+                                  (ext4_lblk_t)le32_to_cpu(newext->ee_block),
+                                   path);
                if (IS_ERR(path)) {
                        err = PTR_ERR(path);
                        goto out;
@@ -1014,6 +1016,150 @@ out:
        return err;
 }
 
+/*
+ * search the closest allocated block to the left for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+int
+ext4_ext_search_left(struct inode *inode, struct ext4_ext_path *path,
+                       ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+       struct ext4_extent_idx *ix;
+       struct ext4_extent *ex;
+       int depth, ee_len;
+
+       BUG_ON(path == NULL);
+       depth = path->p_depth;
+       *phys = 0;
+
+       if (depth == 0 && path->p_ext == NULL)
+               return 0;
+
+       /* usually extent in the path covers blocks smaller
+        * then *logical, but it can be that extent is the
+        * first one in the file */
+
+       ex = path[depth].p_ext;
+       ee_len = ext4_ext_get_actual_len(ex);
+       if (*logical < le32_to_cpu(ex->ee_block)) {
+               BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
+               while (--depth >= 0) {
+                       ix = path[depth].p_idx;
+                       BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
+               }
+               return 0;
+       }
+
+       BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
+
+       *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
+       *phys = ext_pblock(ex) + ee_len - 1;
+       return 0;
+}
+
+/*
+ * search the closest allocated block to the right for *logical
+ * and returns it at @logical + it's physical address at @phys
+ * if *logical is the smallest allocated block, the function
+ * returns 0 at @phys
+ * return value contains 0 (success) or error code
+ */
+int
+ext4_ext_search_right(struct inode *inode, struct ext4_ext_path *path,
+                       ext4_lblk_t *logical, ext4_fsblk_t *phys)
+{
+       struct buffer_head *bh = NULL;
+       struct ext4_extent_header *eh;
+       struct ext4_extent_idx *ix;
+       struct ext4_extent *ex;
+       ext4_fsblk_t block;
+       int depth, ee_len;
+
+       BUG_ON(path == NULL);
+       depth = path->p_depth;
+       *phys = 0;
+
+       if (depth == 0 && path->p_ext == NULL)
+               return 0;
+
+       /* usually extent in the path covers blocks smaller
+        * then *logical, but it can be that extent is the
+        * first one in the file */
+
+       ex = path[depth].p_ext;
+       ee_len = ext4_ext_get_actual_len(ex);
+       if (*logical < le32_to_cpu(ex->ee_block)) {
+               BUG_ON(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex);
+               while (--depth >= 0) {
+                       ix = path[depth].p_idx;
+                       BUG_ON(ix != EXT_FIRST_INDEX(path[depth].p_hdr));
+               }
+               *logical = le32_to_cpu(ex->ee_block);
+               *phys = ext_pblock(ex);
+               return 0;
+       }
+
+       BUG_ON(*logical < (le32_to_cpu(ex->ee_block) + ee_len));
+
+       if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
+               /* next allocated block in this leaf */
+               ex++;
+               *logical = le32_to_cpu(ex->ee_block);
+               *phys = ext_pblock(ex);
+               return 0;
+       }
+
+       /* go up and search for index to the right */
+       while (--depth >= 0) {
+               ix = path[depth].p_idx;
+               if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
+                       break;
+       }
+
+       if (depth < 0) {
+               /* we've gone up to the root and
+                * found no index to the right */
+               return 0;
+       }
+
+       /* we've found index to the right, let's
+        * follow it and find the closest allocated
+        * block to the right */
+       ix++;
+       block = idx_pblock(ix);
+       while (++depth < path->p_depth) {
+               bh = sb_bread(inode->i_sb, block);
+               if (bh == NULL)
+                       return -EIO;
+               eh = ext_block_hdr(bh);
+               if (ext4_ext_check_header(inode, eh, depth)) {
+                       put_bh(bh);
+                       return -EIO;
+               }
+               ix = EXT_FIRST_INDEX(eh);
+               block = idx_pblock(ix);
+               put_bh(bh);
+       }
+
+       bh = sb_bread(inode->i_sb, block);
+       if (bh == NULL)
+               return -EIO;
+       eh = ext_block_hdr(bh);
+       if (ext4_ext_check_header(inode, eh, path->p_depth - depth)) {
+               put_bh(bh);
+               return -EIO;
+       }
+       ex = EXT_FIRST_EXTENT(eh);
+       *logical = le32_to_cpu(ex->ee_block);
+       *phys = ext_pblock(ex);
+       put_bh(bh);
+       return 0;
+
+}
+
 /*
  * ext4_ext_next_allocated_block:
  * returns allocated block in subsequent extent or EXT_MAX_BLOCK.
@@ -1021,7 +1167,7 @@ out:
  * allocated block. Thus, index entries have to be consistent
  * with leaves.
  */
-static unsigned long
+static ext4_lblk_t
 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
 {
        int depth;
@@ -1054,7 +1200,7 @@ ext4_ext_next_allocated_block(struct ext4_ext_path *path)
  * ext4_ext_next_leaf_block:
  * returns first allocated block from next leaf or EXT_MAX_BLOCK
  */
-static unsigned ext4_ext_next_leaf_block(struct inode *inode,
+static ext4_lblk_t ext4_ext_next_leaf_block(struct inode *inode,
                                        struct ext4_ext_path *path)
 {
        int depth;
@@ -1072,7 +1218,8 @@ static unsigned ext4_ext_next_leaf_block(struct inode *inode,
        while (depth >= 0) {
                if (path[depth].p_idx !=
                                EXT_LAST_INDEX(path[depth].p_hdr))
-                 return le32_to_cpu(path[depth].p_idx[1].ei_block);
+                       return (ext4_lblk_t)
+                               le32_to_cpu(path[depth].p_idx[1].ei_block);
                depth--;
        }
 
@@ -1085,7 +1232,7 @@ static unsigned ext4_ext_next_leaf_block(struct inode *inode,
  * then we have to correct all indexes above.
  * TODO: do we need to correct tree in all cases?
  */
-int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
+static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
                                struct ext4_ext_path *path)
 {
        struct ext4_extent_header *eh;
@@ -1171,7 +1318,7 @@ ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
        if (ext1_ee_len + ext2_ee_len > max_len)
                return 0;
 #ifdef AGGRESSIVE_TEST
-       if (le16_to_cpu(ex1->ee_len) >= 4)
+       if (ext1_ee_len >= 4)
                return 0;
 #endif
 
@@ -1239,7 +1386,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
                                    struct ext4_extent *newext,
                                    struct ext4_ext_path *path)
 {
-       unsigned long b1, b2;
+       ext4_lblk_t b1, b2;
        unsigned int depth, len1;
        unsigned int ret = 0;
 
@@ -1260,7 +1407,7 @@ unsigned int ext4_ext_check_overlap(struct inode *inode,
                        goto out;
        }
 
-       /* check for wrap through zero */
+       /* check for wrap through zero on extent logical start block*/
        if (b1 + len1 < b1) {
                len1 = EXT_MAX_BLOCK - b1;
                newext->ee_len = cpu_to_le16(len1);
@@ -1290,7 +1437,8 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
        struct ext4_extent *ex, *fex;
        struct ext4_extent *nearex; /* nearest extent */
        struct ext4_ext_path *npath = NULL;
-       int depth, len, err, next;
+       int depth, len, err;
+       ext4_lblk_t next;
        unsigned uninitialized = 0;
 
        BUG_ON(ext4_ext_get_actual_len(newext) == 0);
@@ -1435,114 +1583,8 @@ cleanup:
        return err;
 }
 
-int ext4_ext_walk_space(struct inode *inode, unsigned long block,
-                       unsigned long num, ext_prepare_callback func,
-                       void *cbdata)
-{
-       struct ext4_ext_path *path = NULL;
-       struct ext4_ext_cache cbex;
-       struct ext4_extent *ex;
-       unsigned long next, start = 0, end = 0;
-       unsigned long last = block + num;
-       int depth, exists, err = 0;
-
-       BUG_ON(func == NULL);
-       BUG_ON(inode == NULL);
-
-       while (block < last && block != EXT_MAX_BLOCK) {
-               num = last - block;
-               /* find extent for this block */
-               path = ext4_ext_find_extent(inode, block, path);
-               if (IS_ERR(path)) {
-                       err = PTR_ERR(path);
-                       path = NULL;
-                       break;
-               }
-
-               depth = ext_depth(inode);
-               BUG_ON(path[depth].p_hdr == NULL);
-               ex = path[depth].p_ext;
-               next = ext4_ext_next_allocated_block(path);
-
-               exists = 0;
-               if (!ex) {
-                       /* there is no extent yet, so try to allocate
-                        * all requested space */
-                       start = block;
-                       end = block + num;
-               } else if (le32_to_cpu(ex->ee_block) > block) {
-                       /* need to allocate space before found extent */
-                       start = block;
-                       end = le32_to_cpu(ex->ee_block);
-                       if (block + num < end)
-                               end = block + num;
-               } else if (block >= le32_to_cpu(ex->ee_block)
-                                       + ext4_ext_get_actual_len(ex)) {
-                       /* need to allocate space after found extent */
-                       start = block;
-                       end = block + num;
-                       if (end >= next)
-                               end = next;
-               } else if (block >= le32_to_cpu(ex->ee_block)) {
-                       /*
-                        * some part of requested space is covered
-                        * by found extent
-                        */
-                       start = block;
-                       end = le32_to_cpu(ex->ee_block)
-                               + ext4_ext_get_actual_len(ex);
-                       if (block + num < end)
-                               end = block + num;
-                       exists = 1;
-               } else {
-                       BUG();
-               }
-               BUG_ON(end <= start);
-
-               if (!exists) {
-                       cbex.ec_block = start;
-                       cbex.ec_len = end - start;
-                       cbex.ec_start = 0;
-                       cbex.ec_type = EXT4_EXT_CACHE_GAP;
-               } else {
-                       cbex.ec_block = le32_to_cpu(ex->ee_block);
-                       cbex.ec_len = ext4_ext_get_actual_len(ex);
-                       cbex.ec_start = ext_pblock(ex);
-                       cbex.ec_type = EXT4_EXT_CACHE_EXTENT;
-               }
-
-               BUG_ON(cbex.ec_len == 0);
-               err = func(inode, path, &cbex, cbdata);
-               ext4_ext_drop_refs(path);
-
-               if (err < 0)
-                       break;
-               if (err == EXT_REPEAT)
-                       continue;
-               else if (err == EXT_BREAK) {
-                       err = 0;
-                       break;
-               }
-
-               if (ext_depth(inode) != depth) {
-                       /* depth was changed. we have to realloc path */
-                       kfree(path);
-                       path = NULL;
-               }
-
-               block = cbex.ec_block + cbex.ec_len;
-       }
-
-       if (path) {
-               ext4_ext_drop_refs(path);
-               kfree(path);
-       }
-
-       return err;
-}
-
 static void
-ext4_ext_put_in_cache(struct inode *inode, __u32 block,
+ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
                        __u32 len, ext4_fsblk_t start, int type)
 {
        struct ext4_ext_cache *cex;
@@ -1561,10 +1603,11 @@ ext4_ext_put_in_cache(struct inode *inode, __u32 block,
  */
 static void
 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
-                               unsigned long block)
+                               ext4_lblk_t block)
 {
        int depth = ext_depth(inode);
-       unsigned long lblock, len;
+       unsigned long len;
+       ext4_lblk_t lblock;
        struct ext4_extent *ex;
 
        ex = path[depth].p_ext;
@@ -1576,32 +1619,34 @@ ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
        } else if (block < le32_to_cpu(ex->ee_block)) {
                lblock = block;
                len = le32_to_cpu(ex->ee_block) - block;
-               ext_debug("cache gap(before): %lu [%lu:%lu]",
-                               (unsigned long) block,
-                               (unsigned long) le32_to_cpu(ex->ee_block),
-                               (unsigned long) ext4_ext_get_actual_len(ex));
+               ext_debug("cache gap(before): %u [%u:%u]",
+                               block,
+                               le32_to_cpu(ex->ee_block),
+                                ext4_ext_get_actual_len(ex));
        } else if (block >= le32_to_cpu(ex->ee_block)
                        + ext4_ext_get_actual_len(ex)) {
+               ext4_lblk_t next;
                lblock = le32_to_cpu(ex->ee_block)
                        + ext4_ext_get_actual_len(ex);
-               len = ext4_ext_next_allocated_block(path);
-               ext_debug("cache gap(after): [%lu:%lu] %lu",
-                               (unsigned long) le32_to_cpu(ex->ee_block),
-                               (unsigned long) ext4_ext_get_actual_len(ex),
-                               (unsigned long) block);
-               BUG_ON(len == lblock);
-               len = len - lblock;
+
+               next = ext4_ext_next_allocated_block(path);
+               ext_debug("cache gap(after): [%u:%u] %u",
+                               le32_to_cpu(ex->ee_block),
+                               ext4_ext_get_actual_len(ex),
+                               block);
+               BUG_ON(next == lblock);
+               len = next - lblock;
        } else {
                lblock = len = 0;
                BUG();
        }
 
-       ext_debug(" -> %lu:%lu\n", (unsigned long) lblock, len);
+       ext_debug(" -> %u:%lu\n", lblock, len);
        ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP);
 }
 
 static int
-ext4_ext_in_cache(struct inode *inode, unsigned long block,
+ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
                        struct ext4_extent *ex)
 {
        struct ext4_ext_cache *cex;
@@ -1618,11 +1663,9 @@ ext4_ext_in_cache(struct inode *inode, unsigned long block,
                ex->ee_block = cpu_to_le32(cex->ec_block);
                ext4_ext_store_pblock(ex, cex->ec_start);
                ex->ee_len = cpu_to_le16(cex->ec_len);
-               ext_debug("%lu cached by %lu:%lu:%llu\n",
-                               (unsigned long) block,
-                               (unsigned long) cex->ec_block,
-                               (unsigned long) cex->ec_len,
-                               cex->ec_start);
+               ext_debug("%u cached by %u:%u:%llu\n",
+                               block,
+                               cex->ec_block, cex->ec_len, cex->ec_start);
                return cex->ec_type;
        }
 
@@ -1636,7 +1679,7 @@ ext4_ext_in_cache(struct inode *inode, unsigned long block,
  * It's used in truncate case only, thus all requests are for
  * last index in the block only.
  */
-int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
+static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
                        struct ext4_ext_path *path)
 {
        struct buffer_head *bh;
@@ -1657,7 +1700,7 @@ int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
        ext_debug("index is empty, remove it, free block %llu\n", leaf);
        bh = sb_find_get_block(inode->i_sb, leaf);
        ext4_forget(handle, 1, inode, bh, leaf);
-       ext4_free_blocks(handle, inode, leaf, 1);
+       ext4_free_blocks(handle, inode, leaf, 1, 1);
        return err;
 }
 
@@ -1666,7 +1709,7 @@ int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
  * This routine returns max. credits that the extent tree can consume.
  * It should be OK for low-performance paths like ->writepage()
  * To allow many writing processes to fit into a single transaction,
- * the caller should calculate credits under truncate_mutex and
+ * the caller should calculate credits under i_data_sem and
  * pass the actual path.
  */
 int ext4_ext_calc_credits_for_insert(struct inode *inode,
@@ -1714,12 +1757,14 @@ int ext4_ext_calc_credits_for_insert(struct inode *inode,
 
 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
                                struct ext4_extent *ex,
-                               unsigned long from, unsigned long to)
+                               ext4_lblk_t from, ext4_lblk_t to)
 {
        struct buffer_head *bh;
        unsigned short ee_len =  ext4_ext_get_actual_len(ex);
-       int i;
+       int i, metadata = 0;
 
+       if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+               metadata = 1;
 #ifdef EXTENTS_STATS
        {
                struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -1738,42 +1783,45 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
        if (from >= le32_to_cpu(ex->ee_block)
            && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
                /* tail removal */
-               unsigned long num;
+               ext4_lblk_t num;
                ext4_fsblk_t start;
+
                num = le32_to_cpu(ex->ee_block) + ee_len - from;
                start = ext_pblock(ex) + ee_len - num;
-               ext_debug("free last %lu blocks starting %llu\n", num, start);
+               ext_debug("free last %u blocks starting %llu\n", num, start);
                for (i = 0; i < num; i++) {
                        bh = sb_find_get_block(inode->i_sb, start + i);
                        ext4_forget(handle, 0, inode, bh, start + i);
                }
-               ext4_free_blocks(handle, inode, start, num);
+               ext4_free_blocks(handle, inode, start, num, metadata);
        } else if (from == le32_to_cpu(ex->ee_block)
                   && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
-               printk("strange request: removal %lu-%lu from %u:%u\n",
+               printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
                        from, to, le32_to_cpu(ex->ee_block), ee_len);
        } else {
-               printk("strange request: removal(2) %lu-%lu from %u:%u\n",
-                       from, to, le32_to_cpu(ex->ee_block), ee_len);
+               printk(KERN_INFO "strange request: removal(2) "
+                               "%u-%u from %u:%u\n",
+                               from, to, le32_to_cpu(ex->ee_block), ee_len);
        }
        return 0;
 }
 
 static int
 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
-               struct ext4_ext_path *path, unsigned long start)
+               struct ext4_ext_path *path, ext4_lblk_t start)
 {
        int err = 0, correct_index = 0;
        int depth = ext_depth(inode), credits;
        struct ext4_extent_header *eh;
-       unsigned a, b, block, num;
-       unsigned long ex_ee_block;
+       ext4_lblk_t a, b, block;
+       unsigned num;
+       ext4_lblk_t ex_ee_block;
        unsigned short ex_ee_len;
        unsigned uninitialized = 0;
        struct ext4_extent *ex;
 
        /* the header must be checked already in ext4_ext_remove_space() */
-       ext_debug("truncate since %lu in leaf\n", start);
+       ext_debug("truncate since %u in leaf\n", start);
        if (!path[depth].p_hdr)
                path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
        eh = path[depth].p_hdr;
@@ -1904,7 +1952,7 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path)
        return 1;
 }
 
-int ext4_ext_remove_space(struct inode *inode, unsigned long start)
+static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
 {
        struct super_block *sb = inode->i_sb;
        int depth = ext_depth(inode);
@@ -1912,7 +1960,7 @@ int ext4_ext_remove_space(struct inode *inode, unsigned long start)
        handle_t *handle;
        int i = 0, err = 0;
 
-       ext_debug("truncate since %lu\n", start);
+       ext_debug("truncate since %u\n", start);
 
        /* probably first extent we're gonna free will be last in block */
        handle = ext4_journal_start(inode, depth + 1);
@@ -2094,17 +2142,19 @@ void ext4_ext_release(struct super_block *sb)
  *   b> Splits in two extents: Write is happening at either end of the extent
  *   c> Splits in three extents: Somone is writing in middle of the extent
  */
-int ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
-                                       struct ext4_ext_path *path,
-                                       ext4_fsblk_t iblock,
-                                       unsigned long max_blocks)
+static int ext4_ext_convert_to_initialized(handle_t *handle,
+                                               struct inode *inode,
+                                               struct ext4_ext_path *path,
+                                               ext4_lblk_t iblock,
+                                               unsigned long max_blocks)
 {
        struct ext4_extent *ex, newex;
        struct ext4_extent *ex1 = NULL;
        struct ext4_extent *ex2 = NULL;
        struct ext4_extent *ex3 = NULL;
        struct ext4_extent_header *eh;
-       unsigned int allocated, ee_block, ee_len, depth;
+       ext4_lblk_t ee_block;
+       unsigned int allocated, ee_len, depth;
        ext4_fsblk_t newblock;
        int err = 0;
        int ret = 0;
@@ -2225,8 +2275,13 @@ out:
        return err ? err : allocated;
 }
 
+/*
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
+ */
 int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
-                       ext4_fsblk_t iblock,
+                       ext4_lblk_t iblock,
                        unsigned long max_blocks, struct buffer_head *bh_result,
                        int create, int extend_disksize)
 {
@@ -2236,11 +2291,11 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
        ext4_fsblk_t goal, newblock;
        int err = 0, depth, ret;
        unsigned long allocated = 0;
+       struct ext4_allocation_request ar;
 
        __clear_bit(BH_New, &bh_result->b_state);
-       ext_debug("blocks %d/%lu requested for inode %u\n", (int) iblock,
-                       max_blocks, (unsigned) inode->i_ino);
-       mutex_lock(&EXT4_I(inode)->truncate_mutex);
+       ext_debug("blocks %u/%lu requested for inode %u\n",
+                       iblock, max_blocks, inode->i_ino);
 
        /* check in cache */
        goal = ext4_ext_in_cache(inode, iblock, &newex);
@@ -2260,7 +2315,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                                   - le32_to_cpu(newex.ee_block)
                                   + ext_pblock(&newex);
                        /* number of remaining blocks in the extent */
-                       allocated = le16_to_cpu(newex.ee_len) -
+                       allocated = ext4_ext_get_actual_len(&newex) -
                                        (iblock - le32_to_cpu(newex.ee_block));
                        goto out;
                } else {
@@ -2288,7 +2343,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 
        ex = path[depth].p_ext;
        if (ex) {
-               unsigned long ee_block = le32_to_cpu(ex->ee_block);
+               ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
                ext4_fsblk_t ee_start = ext_pblock(ex);
                unsigned short ee_len;
 
@@ -2302,7 +2357,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                        newblock = iblock - ee_block + ee_start;
                        /* number of remaining blocks in the extent */
                        allocated = ee_len - (iblock - ee_block);
-                       ext_debug("%d fit into %lu:%d -> %llu\n", (int) iblock,
+                       ext_debug("%u fit into %lu:%d -> %llu\n", iblock,
                                        ee_block, ee_len, newblock);
 
                        /* Do not put uninitialized extent in the cache */
@@ -2320,9 +2375,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                        ret = ext4_ext_convert_to_initialized(handle, inode,
                                                                path, iblock,
                                                                max_blocks);
-                       if (ret <= 0)
+                       if (ret <= 0) {
+                               err = ret;
                                goto out2;
-                       else
+                       else
                                allocated = ret;
                        goto outnew;
                }
@@ -2347,8 +2403,15 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
        if (S_ISREG(inode->i_mode) && (!EXT4_I(inode)->i_block_alloc_info))
                ext4_init_block_alloc_info(inode);
 
-       /* allocate new block */
-       goal = ext4_ext_find_goal(inode, path, iblock);
+       /* find neighbour allocated blocks */
+       ar.lleft = iblock;
+       err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
+       if (err)
+               goto out2;
+       ar.lright = iblock;
+       err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
+       if (err)
+               goto out2;
 
        /*
         * See if request is beyond maximum number of blocks we can have in
@@ -2368,10 +2431,21 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
        newex.ee_len = cpu_to_le16(max_blocks);
        err = ext4_ext_check_overlap(inode, &newex, path);
        if (err)
-               allocated = le16_to_cpu(newex.ee_len);
+               allocated = ext4_ext_get_actual_len(&newex);
        else
                allocated = max_blocks;
-       newblock = ext4_new_blocks(handle, inode, goal, &allocated, &err);
+
+       /* allocate new block */
+       ar.inode = inode;
+       ar.goal = ext4_ext_find_goal(inode, path, iblock);
+       ar.logical = iblock;
+       ar.len = allocated;
+       if (S_ISREG(inode->i_mode))
+               ar.flags = EXT4_MB_HINT_DATA;
+       else
+               /* disable in-core preallocation for non-regular files */
+               ar.flags = 0;
+       newblock = ext4_mb_new_blocks(handle, &ar, &err);
        if (!newblock)
                goto out2;
        ext_debug("allocate new block: goal %llu, found %llu/%lu\n",
@@ -2379,14 +2453,17 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 
        /* try to insert new extent into found leaf and return */
        ext4_ext_store_pblock(&newex, newblock);
-       newex.ee_len = cpu_to_le16(allocated);
+       newex.ee_len = cpu_to_le16(ar.len);
        if (create == EXT4_CREATE_UNINITIALIZED_EXT)  /* Mark uninitialized */
                ext4_ext_mark_uninitialized(&newex);
        err = ext4_ext_insert_extent(handle, inode, path, &newex);
        if (err) {
                /* free data blocks we just allocated */
+               /* not a good idea to call discard here directly,
+                * but otherwise we'd need to call it every free() */
+               ext4_mb_discard_inode_preallocations(inode);
                ext4_free_blocks(handle, inode, ext_pblock(&newex),
-                                       le16_to_cpu(newex.ee_len));
+                                       ext4_ext_get_actual_len(&newex), 0);
                goto out2;
        }
 
@@ -2395,6 +2472,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
 
        /* previous routine could use block we allocated */
        newblock = ext_pblock(&newex);
+       allocated = ext4_ext_get_actual_len(&newex);
 outnew:
        __set_bit(BH_New, &bh_result->b_state);
 
@@ -2414,8 +2492,6 @@ out2:
                ext4_ext_drop_refs(path);
                kfree(path);
        }
-       mutex_unlock(&EXT4_I(inode)->truncate_mutex);
-
        return err ? err : allocated;
 }
 
@@ -2423,7 +2499,7 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
 {
        struct address_space *mapping = inode->i_mapping;
        struct super_block *sb = inode->i_sb;
-       unsigned long last_block;
+       ext4_lblk_t last_block;
        handle_t *handle;
        int err = 0;
 
@@ -2445,9 +2521,11 @@ void ext4_ext_truncate(struct inode * inode, struct page *page)
        if (page)
                ext4_block_truncate_page(handle, page, mapping, inode->i_size);
 
-       mutex_lock(&EXT4_I(inode)->truncate_mutex);
+       down_write(&EXT4_I(inode)->i_data_sem);
        ext4_ext_invalidate_cache(inode);
 
+       ext4_mb_discard_inode_preallocations(inode);
+
        /*
         * TODO: optimization is possible here.
         * Probably we need not scan at all,
@@ -2481,7 +2559,7 @@ out_stop:
        if (inode->i_nlink)
                ext4_orphan_del(handle, inode);
 
-       mutex_unlock(&EXT4_I(inode)->truncate_mutex);
+       up_write(&EXT4_I(inode)->i_data_sem);
        ext4_journal_stop(handle);
 }
 
@@ -2516,7 +2594,8 @@ int ext4_ext_writepage_trans_blocks(struct inode *inode, int num)
 long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
 {
        handle_t *handle;
-       ext4_fsblk_t block, max_blocks;
+       ext4_lblk_t block;
+       unsigned long max_blocks;
        ext4_fsblk_t nblocks = 0;
        int ret = 0;
        int ret2 = 0;
@@ -2544,6 +2623,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
         * modify 1 super block, 1 block bitmap and 1 group descriptor.
         */
        credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3;
+       down_write((&EXT4_I(inode)->i_data_sem));
 retry:
        while (ret >= 0 && ret < max_blocks) {
                block = block + ret;
@@ -2557,12 +2637,12 @@ retry:
                ret = ext4_ext_get_blocks(handle, inode, block,
                                          max_blocks, &map_bh,
                                          EXT4_CREATE_UNINITIALIZED_EXT, 0);
-               WARN_ON(!ret);
-               if (!ret) {
+               WARN_ON(ret <= 0);
+               if (ret <= 0) {
                        ext4_error(inode->i_sb, "ext4_fallocate",
-                                  "ext4_ext_get_blocks returned 0! inode#%lu"
-                                  ", block=%llu, max_blocks=%llu",
-                                  inode->i_ino, block, max_blocks);
+                                   "ext4_ext_get_blocks returned error: "
+                                   "inode#%lu, block=%u, max_blocks=%lu",
+                                   inode->i_ino, block, max_blocks);
                        ret = -EIO;
                        ext4_mark_inode_dirty(handle, inode);
                        ret2 = ext4_journal_stop(handle);
@@ -2600,6 +2680,7 @@ retry:
        if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
                goto retry;
 
+       up_write((&EXT4_I(inode)->i_data_sem));
        /*
         * Time to update the file size.
         * Update only when preallocation was requested beyond the file size.
index 1a81cd66d63b2b2371e4c35025f004657ca66adf..ac35ec58db55c9e9fe4b4d3effde74274b614b25 100644 (file)
@@ -37,9 +37,9 @@ static int ext4_release_file (struct inode * inode, struct file * filp)
        if ((filp->f_mode & FMODE_WRITE) &&
                        (atomic_read(&inode->i_writecount) == 1))
        {
-               mutex_lock(&EXT4_I(inode)->truncate_mutex);
+               down_write(&EXT4_I(inode)->i_data_sem);
                ext4_discard_reservation(inode);
-               mutex_unlock(&EXT4_I(inode)->truncate_mutex);
+               up_write(&EXT4_I(inode)->i_data_sem);
        }
        if (is_dx(inode) && filp->private_data)
                ext4_htree_free_dir_info(filp->private_data);
@@ -56,8 +56,25 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
        ssize_t ret;
        int err;
 
-       ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+       /*
+        * If we have encountered a bitmap-format file, the size limit
+        * is smaller than s_maxbytes, which is for extent-mapped files.
+        */
+
+       if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+               struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+               size_t length = iov_length(iov, nr_segs);
 
+               if (pos > sbi->s_bitmap_maxbytes)
+                       return -EFBIG;
+
+               if (pos + length > sbi->s_bitmap_maxbytes) {
+                       nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
+                                             sbi->s_bitmap_maxbytes - pos);
+               }
+       }
+
+       ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
        /*
         * Skip flushing if there was an error, or if nothing was written.
         */
index 1577910bb58b4135d2bbfbb025c67037cd25785a..7eb0604e7eea8f76973175fc3ee6b247a79171cb 100644 (file)
@@ -14,14 +14,16 @@ extern __le16 ext4_group_desc_csum(struct ext4_sb_info *sbi, __u32 group,
 extern int ext4_group_desc_csum_verify(struct ext4_sb_info *sbi, __u32 group,
                                       struct ext4_group_desc *gdp);
 struct buffer_head *read_block_bitmap(struct super_block *sb,
-                                     unsigned int block_group);
+                                     ext4_group_t block_group);
 extern unsigned ext4_init_block_bitmap(struct super_block *sb,
-                                      struct buffer_head *bh, int group,
+                                      struct buffer_head *bh,
+                                      ext4_group_t group,
                                       struct ext4_group_desc *desc);
 #define ext4_free_blocks_after_init(sb, group, desc)                   \
                ext4_init_block_bitmap(sb, NULL, group, desc)
 extern unsigned ext4_init_inode_bitmap(struct super_block *sb,
-                                      struct buffer_head *bh, int group,
+                                      struct buffer_head *bh,
+                                      ext4_group_t group,
                                       struct ext4_group_desc *desc);
 extern void mark_bitmap_end(int start_bit, int end_bit, char *bitmap);
 #endif /* _LINUX_EXT4_GROUP_H */
index c61f37fd3f05e4d72061791d79600024c858df97..575b5215c8084f3613484555afb0f5727a404826 100644 (file)
@@ -64,8 +64,8 @@ void mark_bitmap_end(int start_bit, int end_bit, char *bitmap)
 }
 
 /* Initializes an uninitialized inode bitmap */
-unsigned ext4_init_inode_bitmap(struct super_block *sb,
-                               struct buffer_head *bh, int block_group,
+unsigned ext4_init_inode_bitmap(struct super_block *sb, struct buffer_head *bh,
+                               ext4_group_t block_group,
                                struct ext4_group_desc *gdp)
 {
        struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -75,7 +75,7 @@ unsigned ext4_init_inode_bitmap(struct super_block *sb,
        /* If checksum is bad mark all blocks and inodes use to prevent
         * allocation, essentially implementing a per-group read-only flag. */
        if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) {
-               ext4_error(sb, __FUNCTION__, "Checksum bad for group %u\n",
+               ext4_error(sb, __FUNCTION__, "Checksum bad for group %lu\n",
                           block_group);
                gdp->bg_free_blocks_count = 0;
                gdp->bg_free_inodes_count = 0;
@@ -98,7 +98,7 @@ unsigned ext4_init_inode_bitmap(struct super_block *sb,
  * Return buffer_head of bitmap on success or NULL.
  */
 static struct buffer_head *
-read_inode_bitmap(struct super_block * sb, unsigned long block_group)
+read_inode_bitmap(struct super_block *sb, ext4_group_t block_group)
 {
        struct ext4_group_desc *desc;
        struct buffer_head *bh = NULL;
@@ -152,7 +152,7 @@ void ext4_free_inode (handle_t *handle, struct inode * inode)
        unsigned long ino;
        struct buffer_head *bitmap_bh = NULL;
        struct buffer_head *bh2;
-       unsigned long block_group;
+       ext4_group_t block_group;
        unsigned long bit;
        struct ext4_group_desc * gdp;
        struct ext4_super_block * es;
@@ -260,12 +260,14 @@ error_return:
  * For other inodes, search forward from the parent directory\'s block
  * group to find a free inode.
  */
-static int find_group_dir(struct super_block *sb, struct inode *parent)
+static int find_group_dir(struct super_block *sb, struct inode *parent,
+                               ext4_group_t *best_group)
 {
-       int ngroups = EXT4_SB(sb)->s_groups_count;
+       ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
        unsigned int freei, avefreei;
        struct ext4_group_desc *desc, *best_desc = NULL;
-       int group, best_group = -1;
+       ext4_group_t group;
+       int ret = -1;
 
        freei = percpu_counter_read_positive(&EXT4_SB(sb)->s_freeinodes_counter);
        avefreei = freei / ngroups;
@@ -279,11 +281,12 @@ static int find_group_dir(struct super_block *sb, struct inode *parent)
                if (!best_desc ||
                    (le16_to_cpu(desc->bg_free_blocks_count) >
                     le16_to_cpu(best_desc->bg_free_blocks_count))) {
-                       best_group = group;
+                       *best_group = group;
                        best_desc = desc;
+                       ret = 0;
                }
        }
-       return best_group;
+       return ret;
 }
 
 /*
@@ -314,12 +317,13 @@ static int find_group_dir(struct super_block *sb, struct inode *parent)
 #define INODE_COST 64
 #define BLOCK_COST 256
 
-static int find_group_orlov(struct super_block *sb, struct inode *parent)
+static int find_group_orlov(struct super_block *sb, struct inode *parent,
+                               ext4_group_t *group)
 {
-       int parent_group = EXT4_I(parent)->i_block_group;
+       ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
        struct ext4_sb_info *sbi = EXT4_SB(sb);
        struct ext4_super_block *es = sbi->s_es;
-       int ngroups = sbi->s_groups_count;
+       ext4_group_t ngroups = sbi->s_groups_count;
        int inodes_per_group = EXT4_INODES_PER_GROUP(sb);
        unsigned int freei, avefreei;
        ext4_fsblk_t freeb, avefreeb;
@@ -327,7 +331,7 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
        unsigned int ndirs;
        int max_debt, max_dirs, min_inodes;
        ext4_grpblk_t min_blocks;
-       int group = -1, i;
+       ext4_group_t i;
        struct ext4_group_desc *desc;
 
        freei = percpu_counter_read_positive(&sbi->s_freeinodes_counter);
@@ -340,13 +344,14 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
        if ((parent == sb->s_root->d_inode) ||
            (EXT4_I(parent)->i_flags & EXT4_TOPDIR_FL)) {
                int best_ndir = inodes_per_group;
-               int best_group = -1;
+               ext4_group_t grp;
+               int ret = -1;
 
-               get_random_bytes(&group, sizeof(group));
-               parent_group = (unsigned)group % ngroups;
+               get_random_bytes(&grp, sizeof(grp));
+               parent_group = (unsigned)grp % ngroups;
                for (i = 0; i < ngroups; i++) {
-                       group = (parent_group + i) % ngroups;
-                       desc = ext4_get_group_desc (sb, group, NULL);
+                       grp = (parent_group + i) % ngroups;
+                       desc = ext4_get_group_desc(sb, grp, NULL);
                        if (!desc || !desc->bg_free_inodes_count)
                                continue;
                        if (le16_to_cpu(desc->bg_used_dirs_count) >= best_ndir)
@@ -355,11 +360,12 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
                                continue;
                        if (le16_to_cpu(desc->bg_free_blocks_count) < avefreeb)
                                continue;
-                       best_group = group;
+                       *group = grp;
+                       ret = 0;
                        best_ndir = le16_to_cpu(desc->bg_used_dirs_count);
                }
-               if (best_group >= 0)
-                       return best_group;
+               if (ret == 0)
+                       return ret;
                goto fallback;
        }
 
@@ -380,8 +386,8 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
                max_debt = 1;
 
        for (i = 0; i < ngroups; i++) {
-               group = (parent_group + i) % ngroups;
-               desc = ext4_get_group_desc (sb, group, NULL);
+               *group = (parent_group + i) % ngroups;
+               desc = ext4_get_group_desc(sb, *group, NULL);
                if (!desc || !desc->bg_free_inodes_count)
                        continue;
                if (le16_to_cpu(desc->bg_used_dirs_count) >= max_dirs)
@@ -390,17 +396,16 @@ static int find_group_orlov(struct super_block *sb, struct inode *parent)
                        continue;
                if (le16_to_cpu(desc->bg_free_blocks_count) < min_blocks)
                        continue;
-               return group;
+               return 0;
        }
 
 fallback:
        for (i = 0; i < ngroups; i++) {
-               group = (parent_group + i) % ngroups;
-               desc = ext4_get_group_desc (sb, group, NULL);
-               if (!desc || !desc->bg_free_inodes_count)
-                       continue;
-               if (le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
-                       return group;
+               *group = (parent_group + i) % ngroups;
+               desc = ext4_get_group_desc(sb, *group, NULL);
+               if (desc && desc->bg_free_inodes_count &&
+                       le16_to_cpu(desc->bg_free_inodes_count) >= avefreei)
+                       return 0;
        }
 
        if (avefreei) {
@@ -415,21 +420,22 @@ fallback:
        return -1;
 }
 
-static int find_group_other(struct super_block *sb, struct inode *parent)
+static int find_group_other(struct super_block *sb, struct inode *parent,
+                               ext4_group_t *group)
 {
-       int parent_group = EXT4_I(parent)->i_block_group;
-       int ngroups = EXT4_SB(sb)->s_groups_count;
+       ext4_group_t parent_group = EXT4_I(parent)->i_block_group;
+       ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count;
        struct ext4_group_desc *desc;
-       int group, i;
+       ext4_group_t i;
 
        /*
         * Try to place the inode in its parent directory
         */
-       group = parent_group;
-       desc = ext4_get_group_desc (sb, group, NULL);
+       *group = parent_group;
+       desc = ext4_get_group_desc(sb, *group, NULL);
        if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
                        le16_to_cpu(desc->bg_free_blocks_count))
-               return group;
+               return 0;
 
        /*
         * We're going to place this inode in a different blockgroup from its
@@ -440,33 +446,33 @@ static int find_group_other(struct super_block *sb, struct inode *parent)
         *
         * So add our directory's i_ino into the starting point for the hash.
         */
-       group = (group + parent->i_ino) % ngroups;
+       *group = (*group + parent->i_ino) % ngroups;
 
        /*
         * Use a quadratic hash to find a group with a free inode and some free
         * blocks.
         */
        for (i = 1; i < ngroups; i <<= 1) {
-               group += i;
-               if (group >= ngroups)
-                       group -= ngroups;
-               desc = ext4_get_group_desc (sb, group, NULL);
+               *group += i;
+               if (*group >= ngroups)
+                       *group -= ngroups;
+               desc = ext4_get_group_desc(sb, *group, NULL);
                if (desc && le16_to_cpu(desc->bg_free_inodes_count) &&
                                le16_to_cpu(desc->bg_free_blocks_count))
-                       return group;
+                       return 0;
        }
 
        /*
         * That failed: try linear search for a free inode, even if that group
         * has no free blocks.
         */
-       group = parent_group;
+       *group = parent_group;
        for (i = 0; i < ngroups; i++) {
-               if (++group >= ngroups)
-                       group = 0;
-               desc = ext4_get_group_desc (sb, group, NULL);
+               if (++*group >= ngroups)
+                       *group = 0;
+               desc = ext4_get_group_desc(sb, *group, NULL);
                if (desc && le16_to_cpu(desc->bg_free_inodes_count))
-                       return group;
+                       return 0;
        }
 
        return -1;
@@ -487,16 +493,17 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
        struct super_block *sb;
        struct buffer_head *bitmap_bh = NULL;
        struct buffer_head *bh2;
-       int group;
+       ext4_group_t group = 0;
        unsigned long ino = 0;
        struct inode * inode;
        struct ext4_group_desc * gdp = NULL;
        struct ext4_super_block * es;
        struct ext4_inode_info *ei;
        struct ext4_sb_info *sbi;
-       int err = 0;
+       int ret2, err = 0;
        struct inode *ret;
-       int i, free = 0;
+       ext4_group_t i;
+       int free = 0;
 
        /* Cannot create files in a deleted directory */
        if (!dir || !dir->i_nlink)
@@ -512,14 +519,14 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
        es = sbi->s_es;
        if (S_ISDIR(mode)) {
                if (test_opt (sb, OLDALLOC))
-                       group = find_group_dir(sb, dir);
+                       ret2 = find_group_dir(sb, dir, &group);
                else
-                       group = find_group_orlov(sb, dir);
+                       ret2 = find_group_orlov(sb, dir, &group);
        } else
-               group = find_group_other(sb, dir);
+               ret2 = find_group_other(sb, dir, &group);
 
        err = -ENOSPC;
-       if (group == -1)
+       if (ret2 == -1)
                goto out;
 
        for (i = 0; i < sbi->s_groups_count; i++) {
@@ -583,7 +590,7 @@ got:
            ino > EXT4_INODES_PER_GROUP(sb)) {
                ext4_error(sb, __FUNCTION__,
                           "reserved inode or inode > inodes count - "
-                          "block_group = %d, inode=%lu", group,
+                          "block_group = %lu, inode=%lu", group,
                           ino + group * EXT4_INODES_PER_GROUP(sb));
                err = -EIO;
                goto fail;
@@ -702,7 +709,6 @@ got:
        if (!S_ISDIR(mode))
                ei->i_flags &= ~EXT4_DIRSYNC_FL;
        ei->i_file_acl = 0;
-       ei->i_dir_acl = 0;
        ei->i_dtime = 0;
        ei->i_block_alloc_info = NULL;
        ei->i_block_group = group;
@@ -741,13 +747,10 @@ got:
        if (test_opt(sb, EXTENTS)) {
                EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
                ext4_ext_tree_init(handle, inode);
-               if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
-                       err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
-                       if (err) goto fail;
-                       EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS);
-                       BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "call ext4_journal_dirty_metadata");
-                       err = ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
-               }
+               err = ext4_update_incompat_feature(handle, sb,
+                                               EXT4_FEATURE_INCOMPAT_EXTENTS);
+               if (err)
+                       goto fail;
        }
 
        ext4_debug("allocating inode %lu\n", inode->i_ino);
@@ -777,7 +780,7 @@ fail_drop:
 struct inode *ext4_orphan_get(struct super_block *sb, unsigned long ino)
 {
        unsigned long max_ino = le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count);
-       unsigned long block_group;
+       ext4_group_t block_group;
        int bit;
        struct buffer_head *bitmap_bh = NULL;
        struct inode *inode = NULL;
@@ -833,7 +836,7 @@ unsigned long ext4_count_free_inodes (struct super_block * sb)
 {
        unsigned long desc_count;
        struct ext4_group_desc *gdp;
-       int i;
+       ext4_group_t i;
 #ifdef EXT4FS_DEBUG
        struct ext4_super_block *es;
        unsigned long bitmap_count, x;
@@ -854,7 +857,7 @@ unsigned long ext4_count_free_inodes (struct super_block * sb)
                        continue;
 
                x = ext4_count_free(bitmap_bh, EXT4_INODES_PER_GROUP(sb) / 8);
-               printk("group %d: stored = %d, counted = %lu\n",
+               printk(KERN_DEBUG "group %lu: stored = %d, counted = %lu\n",
                        i, le16_to_cpu(gdp->bg_free_inodes_count), x);
                bitmap_count += x;
        }
@@ -879,7 +882,7 @@ unsigned long ext4_count_free_inodes (struct super_block * sb)
 unsigned long ext4_count_dirs (struct super_block * sb)
 {
        unsigned long count = 0;
-       int i;
+       ext4_group_t i;
 
        for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
                struct ext4_group_desc *gdp = ext4_get_group_desc (sb, i, NULL);
index 5489703d95738ffb075ed7cb275aab94eb4d74e6..bb717cbb749c822265bccdd8159de7af456ad745 100644 (file)
@@ -105,7 +105,7 @@ int ext4_forget(handle_t *handle, int is_metadata, struct inode *inode,
  */
 static unsigned long blocks_for_truncate(struct inode *inode)
 {
-       unsigned long needed;
+       ext4_lblk_t needed;
 
        needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
 
@@ -243,13 +243,6 @@ static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
        p->bh = bh;
 }
 
-static int verify_chain(Indirect *from, Indirect *to)
-{
-       while (from <= to && from->key == *from->p)
-               from++;
-       return (from > to);
-}
-
 /**
  *     ext4_block_to_path - parse the block number into array of offsets
  *     @inode: inode in question (we are only interested in its superblock)
@@ -282,7 +275,8 @@ static int verify_chain(Indirect *from, Indirect *to)
  */
 
 static int ext4_block_to_path(struct inode *inode,
-                       long i_block, int offsets[4], int *boundary)
+                       ext4_lblk_t i_block,
+                       ext4_lblk_t offsets[4], int *boundary)
 {
        int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
        int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
@@ -313,7 +307,10 @@ static int ext4_block_to_path(struct inode *inode,
                offsets[n++] = i_block & (ptrs - 1);
                final = ptrs;
        } else {
-               ext4_warning(inode->i_sb, "ext4_block_to_path", "block > big");
+               ext4_warning(inode->i_sb, "ext4_block_to_path",
+                               "block %lu > max",
+                               i_block + direct_blocks +
+                               indirect_blocks + double_blocks);
        }
        if (boundary)
                *boundary = final - 1 - (i_block & (ptrs - 1));
@@ -344,12 +341,14 @@ static int ext4_block_to_path(struct inode *inode,
  *             (pointer to last triple returned, *@err == 0)
  *     or when it gets an IO error reading an indirect block
  *             (ditto, *@err == -EIO)
- *     or when it notices that chain had been changed while it was reading
- *             (ditto, *@err == -EAGAIN)
  *     or when it reads all @depth-1 indirect blocks successfully and finds
  *     the whole chain, all way to the data (returns %NULL, *err == 0).
+ *
+ *      Need to be called with
+ *      down_read(&EXT4_I(inode)->i_data_sem)
  */
-static Indirect *ext4_get_branch(struct inode *inode, int depth, int *offsets,
+static Indirect *ext4_get_branch(struct inode *inode, int depth,
+                                ext4_lblk_t  *offsets,
                                 Indirect chain[4], int *err)
 {
        struct super_block *sb = inode->i_sb;
@@ -365,9 +364,6 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth, int *offsets,
                bh = sb_bread(sb, le32_to_cpu(p->key));
                if (!bh)
                        goto failure;
-               /* Reader: pointers */
-               if (!verify_chain(chain, p))
-                       goto changed;
                add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
                /* Reader: end */
                if (!p->key)
@@ -375,10 +371,6 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth, int *offsets,
        }
        return NULL;
 
-changed:
-       brelse(bh);
-       *err = -EAGAIN;
-       goto no_block;
 failure:
        *err = -EIO;
 no_block:
@@ -445,7 +437,7 @@ static ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
  *     stores it in *@goal and returns zero.
  */
 
-static ext4_fsblk_t ext4_find_goal(struct inode *inode, long block,
+static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
                Indirect chain[4], Indirect *partial)
 {
        struct ext4_block_alloc_info *block_i;
@@ -559,7 +551,7 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
        return ret;
 failed_out:
        for (i = 0; i <index; i++)
-               ext4_free_blocks(handle, inode, new_blocks[i], 1);
+               ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
        return ret;
 }
 
@@ -590,7 +582,7 @@ failed_out:
  */
 static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
                        int indirect_blks, int *blks, ext4_fsblk_t goal,
-                       int *offsets, Indirect *branch)
+                       ext4_lblk_t *offsets, Indirect *branch)
 {
        int blocksize = inode->i_sb->s_blocksize;
        int i, n = 0;
@@ -658,9 +650,9 @@ failed:
                ext4_journal_forget(handle, branch[i].bh);
        }
        for (i = 0; i <indirect_blks; i++)
-               ext4_free_blocks(handle, inode, new_blocks[i], 1);
+               ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
 
-       ext4_free_blocks(handle, inode, new_blocks[i], num);
+       ext4_free_blocks(handle, inode, new_blocks[i], num, 0);
 
        return err;
 }
@@ -680,7 +672,7 @@ failed:
  * chain to new block and return 0.
  */
 static int ext4_splice_branch(handle_t *handle, struct inode *inode,
-                       long block, Indirect *where, int num, int blks)
+                       ext4_lblk_t block, Indirect *where, int num, int blks)
 {
        int i;
        int err = 0;
@@ -757,9 +749,10 @@ err_out:
        for (i = 1; i <= num; i++) {
                BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget");
                ext4_journal_forget(handle, where[i].bh);
-               ext4_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
+               ext4_free_blocks(handle, inode,
+                                       le32_to_cpu(where[i-1].key), 1, 0);
        }
-       ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
+       ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0);
 
        return err;
 }
@@ -782,14 +775,19 @@ err_out:
  * return > 0, # of blocks mapped or allocated.
  * return = 0, if plain lookup failed.
  * return < 0, error case.
+ *
+ *
+ * Need to be called with
+ * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
+ * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
  */
 int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
-               sector_t iblock, unsigned long maxblocks,
+               ext4_lblk_t iblock, unsigned long maxblocks,
                struct buffer_head *bh_result,
                int create, int extend_disksize)
 {
        int err = -EIO;
-       int offsets[4];
+       ext4_lblk_t offsets[4];
        Indirect chain[4];
        Indirect *partial;
        ext4_fsblk_t goal;
@@ -803,7 +801,8 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
 
        J_ASSERT(!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL));
        J_ASSERT(handle != NULL || create == 0);
-       depth = ext4_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
+       depth = ext4_block_to_path(inode, iblock, offsets,
+                                       &blocks_to_boundary);
 
        if (depth == 0)
                goto out;
@@ -819,18 +818,6 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
                while (count < maxblocks && count <= blocks_to_boundary) {
                        ext4_fsblk_t blk;
 
-                       if (!verify_chain(chain, partial)) {
-                               /*
-                                * Indirect block might be removed by
-                                * truncate while we were reading it.
-                                * Handling of that case: forget what we've
-                                * got now. Flag the err as EAGAIN, so it
-                                * will reread.
-                                */
-                               err = -EAGAIN;
-                               count = 0;
-                               break;
-                       }
                        blk = le32_to_cpu(*(chain[depth-1].p + count));
 
                        if (blk == first_block + count)
@@ -838,44 +825,13 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
                        else
                                break;
                }
-               if (err != -EAGAIN)
-                       goto got_it;
+               goto got_it;
        }
 
        /* Next simple case - plain lookup or failed read of indirect block */
        if (!create || err == -EIO)
                goto cleanup;
 
-       mutex_lock(&ei->truncate_mutex);
-
-       /*
-        * If the indirect block is missing while we are reading
-        * the chain(ext4_get_branch() returns -EAGAIN err), or
-        * if the chain has been changed after we grab the semaphore,
-        * (either because another process truncated this branch, or
-        * another get_block allocated this branch) re-grab the chain to see if
-        * the request block has been allocated or not.
-        *
-        * Since we already block the truncate/other get_block
-        * at this point, we will have the current copy of the chain when we
-        * splice the branch into the tree.
-        */
-       if (err == -EAGAIN || !verify_chain(chain, partial)) {
-               while (partial > chain) {
-                       brelse(partial->bh);
-                       partial--;
-               }
-               partial = ext4_get_branch(inode, depth, offsets, chain, &err);
-               if (!partial) {
-                       count++;
-                       mutex_unlock(&ei->truncate_mutex);
-                       if (err)
-                               goto cleanup;
-                       clear_buffer_new(bh_result);
-                       goto got_it;
-               }
-       }
-
        /*
         * Okay, we need to do block allocation.  Lazily initialize the block
         * allocation info here if necessary
@@ -911,13 +867,12 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode,
                err = ext4_splice_branch(handle, inode, iblock,
                                        partial, indirect_blks, count);
        /*
-        * i_disksize growing is protected by truncate_mutex.  Don't forget to
+        * i_disksize growing is protected by i_data_sem.  Don't forget to
         * protect it if you're about to implement concurrent
         * ext4_get_block() -bzzz
        */
        if (!err && extend_disksize && inode->i_size > ei->i_disksize)
                ei->i_disksize = inode->i_size;
-       mutex_unlock(&ei->truncate_mutex);
        if (err)
                goto cleanup;
 
@@ -942,6 +897,47 @@ out:
 
 #define DIO_CREDITS (EXT4_RESERVE_TRANS_BLOCKS + 32)
 
+int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
+                       unsigned long max_blocks, struct buffer_head *bh,
+                       int create, int extend_disksize)
+{
+       int retval;
+       /*
+        * Try to see if we can get  the block without requesting
+        * for new file system block.
+        */
+       down_read((&EXT4_I(inode)->i_data_sem));
+       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
+               retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,
+                               bh, 0, 0);
+       } else {
+               retval = ext4_get_blocks_handle(handle,
+                               inode, block, max_blocks, bh, 0, 0);
+       }
+       up_read((&EXT4_I(inode)->i_data_sem));
+       if (!create || (retval > 0))
+               return retval;
+
+       /*
+        * We need to allocate new blocks which will result
+        * in i_data update
+        */
+       down_write((&EXT4_I(inode)->i_data_sem));
+       /*
+        * We need to check for EXT4 here because migrate
+        * could have changed the inode type in between
+        */
+       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
+               retval =  ext4_ext_get_blocks(handle, inode, block, max_blocks,
+                               bh, create, extend_disksize);
+       } else {
+               retval = ext4_get_blocks_handle(handle, inode, block,
+                               max_blocks, bh, create, extend_disksize);
+       }
+       up_write((&EXT4_I(inode)->i_data_sem));
+       return retval;
+}
+
 static int ext4_get_block(struct inode *inode, sector_t iblock,
                        struct buffer_head *bh_result, int create)
 {
@@ -996,7 +992,7 @@ get_block:
  * `handle' can be NULL if create is zero
  */
 struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
-                               long block, int create, int *errp)
+                               ext4_lblk_t block, int create, int *errp)
 {
        struct buffer_head dummy;
        int fatal = 0, err;
@@ -1063,7 +1059,7 @@ err:
 }
 
 struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
-                              int block, int create, int *err)
+                              ext4_lblk_t block, int create, int *err)
 {
        struct buffer_head * bh;
 
@@ -1446,7 +1442,7 @@ static int jbd2_journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
  *     ext4_file_write() -> generic_file_write() -> __alloc_pages() -> ...
  *
  * Same applies to ext4_get_block().  We will deadlock on various things like
- * lock_journal and i_truncate_mutex.
+ * lock_journal and i_data_sem
  *
  * Setting PF_MEMALLOC here doesn't work - too many internal memory
  * allocations fail.
@@ -1828,7 +1824,8 @@ int ext4_block_truncate_page(handle_t *handle, struct page *page,
 {
        ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
        unsigned offset = from & (PAGE_CACHE_SIZE-1);
-       unsigned blocksize, iblock, length, pos;
+       unsigned blocksize, length, pos;
+       ext4_lblk_t iblock;
        struct inode *inode = mapping->host;
        struct buffer_head *bh;
        int err = 0;
@@ -1964,7 +1961,7 @@ static inline int all_zeroes(__le32 *p, __le32 *q)
  *                     (no partially truncated stuff there).  */
 
 static Indirect *ext4_find_shared(struct inode *inode, int depth,
-                       int offsets[4], Indirect chain[4], __le32 *top)
+                       ext4_lblk_t offsets[4], Indirect chain[4], __le32 *top)
 {
        Indirect *partial, *p;
        int k, err;
@@ -2048,15 +2045,15 @@ static void ext4_clear_blocks(handle_t *handle, struct inode *inode,
        for (p = first; p < last; p++) {
                u32 nr = le32_to_cpu(*p);
                if (nr) {
-                       struct buffer_head *bh;
+                       struct buffer_head *tbh;
 
                        *p = 0;
-                       bh = sb_find_get_block(inode->i_sb, nr);
-                       ext4_forget(handle, 0, inode, bh, nr);
+                       tbh = sb_find_get_block(inode->i_sb, nr);
+                       ext4_forget(handle, 0, inode, tbh, nr);
                }
        }
 
-       ext4_free_blocks(handle, inode, block_to_free, count);
+       ext4_free_blocks(handle, inode, block_to_free, count, 0);
 }
 
 /**
@@ -2229,7 +2226,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
                                ext4_journal_test_restart(handle, inode);
                        }
 
-                       ext4_free_blocks(handle, inode, nr, 1);
+                       ext4_free_blocks(handle, inode, nr, 1, 1);
 
                        if (parent_bh) {
                                /*
@@ -2289,12 +2286,12 @@ void ext4_truncate(struct inode *inode)
        __le32 *i_data = ei->i_data;
        int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
        struct address_space *mapping = inode->i_mapping;
-       int offsets[4];
+       ext4_lblk_t offsets[4];
        Indirect chain[4];
        Indirect *partial;
        __le32 nr = 0;
        int n;
-       long last_block;
+       ext4_lblk_t last_block;
        unsigned blocksize = inode->i_sb->s_blocksize;
        struct page *page;
 
@@ -2320,8 +2317,10 @@ void ext4_truncate(struct inode *inode)
                        return;
        }
 
-       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)
-               return ext4_ext_truncate(inode, page);
+       if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) {
+               ext4_ext_truncate(inode, page);
+               return;
+       }
 
        handle = start_transaction(inode);
        if (IS_ERR(handle)) {
@@ -2369,7 +2368,7 @@ void ext4_truncate(struct inode *inode)
         * From here we block out all ext4_get_block() callers who want to
         * modify the block allocation tree.
         */
-       mutex_lock(&ei->truncate_mutex);
+       down_write(&ei->i_data_sem);
 
        if (n == 1) {           /* direct blocks */
                ext4_free_data(handle, inode, NULL, i_data+offsets[0],
@@ -2433,7 +2432,7 @@ do_indirects:
 
        ext4_discard_reservation(inode);
 
-       mutex_unlock(&ei->truncate_mutex);
+       up_write(&ei->i_data_sem);
        inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
        ext4_mark_inode_dirty(handle, inode);
 
@@ -2460,7 +2459,8 @@ out_stop:
 static ext4_fsblk_t ext4_get_inode_block(struct super_block *sb,
                unsigned long ino, struct ext4_iloc *iloc)
 {
-       unsigned long desc, group_desc, block_group;
+       unsigned long desc, group_desc;
+       ext4_group_t block_group;
        unsigned long offset;
        ext4_fsblk_t block;
        struct buffer_head *bh;
@@ -2547,7 +2547,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
                        struct ext4_group_desc *desc;
                        int inodes_per_buffer;
                        int inode_offset, i;
-                       int block_group;
+                       ext4_group_t block_group;
                        int start;
 
                        block_group = (inode->i_ino - 1) /
@@ -2660,6 +2660,28 @@ void ext4_get_inode_flags(struct ext4_inode_info *ei)
        if (flags & S_DIRSYNC)
                ei->i_flags |= EXT4_DIRSYNC_FL;
 }
+static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
+                                       struct ext4_inode_info *ei)
+{
+       blkcnt_t i_blocks ;
+       struct inode *inode = &(ei->vfs_inode);
+       struct super_block *sb = inode->i_sb;
+
+       if (EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                               EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
+               /* we are using combined 48 bit field */
+               i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
+                                       le32_to_cpu(raw_inode->i_blocks_lo);
+               if (ei->i_flags & EXT4_HUGE_FILE_FL) {
+                       /* i_blocks represent file system block size */
+                       return i_blocks  << (inode->i_blkbits - 9);
+               } else {
+                       return i_blocks;
+               }
+       } else {
+               return le32_to_cpu(raw_inode->i_blocks_lo);
+       }
+}
 
 void ext4_read_inode(struct inode * inode)
 {
@@ -2687,7 +2709,6 @@ void ext4_read_inode(struct inode * inode)
                inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
        }
        inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
-       inode->i_size = le32_to_cpu(raw_inode->i_size);
 
        ei->i_state = 0;
        ei->i_dir_start_lookup = 0;
@@ -2709,19 +2730,15 @@ void ext4_read_inode(struct inode * inode)
                 * recovery code: that's fine, we're about to complete
                 * the process of deleting those. */
        }
-       inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
        ei->i_flags = le32_to_cpu(raw_inode->i_flags);
-       ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+       inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
+       ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
        if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
-           cpu_to_le32(EXT4_OS_HURD))
+           cpu_to_le32(EXT4_OS_HURD)) {
                ei->i_file_acl |=
                        ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
-       if (!S_ISREG(inode->i_mode)) {
-               ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
-       } else {
-               inode->i_size |=
-                       ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
        }
+       inode->i_size = ext4_isize(raw_inode);
        ei->i_disksize = inode->i_size;
        inode->i_generation = le32_to_cpu(raw_inode->i_generation);
        ei->i_block_group = iloc.block_group;
@@ -2765,6 +2782,13 @@ void ext4_read_inode(struct inode * inode)
        EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
        EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);
 
+       inode->i_version = le32_to_cpu(raw_inode->i_disk_version);
+       if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
+               if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+                       inode->i_version |=
+                       (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
+       }
+
        if (S_ISREG(inode->i_mode)) {
                inode->i_op = &ext4_file_inode_operations;
                inode->i_fop = &ext4_file_operations;
@@ -2797,6 +2821,55 @@ bad_inode:
        return;
 }
 
+static int ext4_inode_blocks_set(handle_t *handle,
+                               struct ext4_inode *raw_inode,
+                               struct ext4_inode_info *ei)
+{
+       struct inode *inode = &(ei->vfs_inode);
+       u64 i_blocks = inode->i_blocks;
+       struct super_block *sb = inode->i_sb;
+       int err = 0;
+
+       if (i_blocks <= ~0U) {
+               /*
+                * i_blocks can be represnted in a 32 bit variable
+                * as multiple of 512 bytes
+                */
+               raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
+               raw_inode->i_blocks_high = 0;
+               ei->i_flags &= ~EXT4_HUGE_FILE_FL;
+       } else if (i_blocks <= 0xffffffffffffULL) {
+               /*
+                * i_blocks can be represented in a 48 bit variable
+                * as multiple of 512 bytes
+                */
+               err = ext4_update_rocompat_feature(handle, sb,
+                                           EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
+               if (err)
+                       goto  err_out;
+               /* i_block is stored in the split  48 bit fields */
+               raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
+               raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
+               ei->i_flags &= ~EXT4_HUGE_FILE_FL;
+       } else {
+               /*
+                * i_blocks should be represented in a 48 bit variable
+                * as multiple of  file system block size
+                */
+               err = ext4_update_rocompat_feature(handle, sb,
+                                           EXT4_FEATURE_RO_COMPAT_HUGE_FILE);
+               if (err)
+                       goto  err_out;
+               ei->i_flags |= EXT4_HUGE_FILE_FL;
+               /* i_block is stored in file system block size */
+               i_blocks = i_blocks >> (inode->i_blkbits - 9);
+               raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
+               raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
+       }
+err_out:
+       return err;
+}
+
 /*
  * Post the struct inode info into an on-disk inode location in the
  * buffer-cache.  This gobbles the caller's reference to the
@@ -2845,47 +2918,42 @@ static int ext4_do_update_inode(handle_t *handle,
                raw_inode->i_gid_high = 0;
        }
        raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
-       raw_inode->i_size = cpu_to_le32(ei->i_disksize);
 
        EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
        EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
        EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
        EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);
 
-       raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
+       if (ext4_inode_blocks_set(handle, raw_inode, ei))
+               goto out_brelse;
        raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
        raw_inode->i_flags = cpu_to_le32(ei->i_flags);
        if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
            cpu_to_le32(EXT4_OS_HURD))
                raw_inode->i_file_acl_high =
                        cpu_to_le16(ei->i_file_acl >> 32);
-       raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
-       if (!S_ISREG(inode->i_mode)) {
-               raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
-       } else {
-               raw_inode->i_size_high =
-                       cpu_to_le32(ei->i_disksize >> 32);
-               if (ei->i_disksize > 0x7fffffffULL) {
-                       struct super_block *sb = inode->i_sb;
-                       if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
-                                       EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
-                           EXT4_SB(sb)->s_es->s_rev_level ==
-                                       cpu_to_le32(EXT4_GOOD_OLD_REV)) {
-                              /* If this is the first large file
-                               * created, add a flag to the superblock.
-                               */
-                               err = ext4_journal_get_write_access(handle,
-                                               EXT4_SB(sb)->s_sbh);
-                               if (err)
-                                       goto out_brelse;
-                               ext4_update_dynamic_rev(sb);
-                               EXT4_SET_RO_COMPAT_FEATURE(sb,
+       raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
+       ext4_isize_set(raw_inode, ei->i_disksize);
+       if (ei->i_disksize > 0x7fffffffULL) {
+               struct super_block *sb = inode->i_sb;
+               if (!EXT4_HAS_RO_COMPAT_FEATURE(sb,
+                               EXT4_FEATURE_RO_COMPAT_LARGE_FILE) ||
+                               EXT4_SB(sb)->s_es->s_rev_level ==
+                               cpu_to_le32(EXT4_GOOD_OLD_REV)) {
+                       /* If this is the first large file
+                        * created, add a flag to the superblock.
+                        */
+                       err = ext4_journal_get_write_access(handle,
+                                       EXT4_SB(sb)->s_sbh);
+                       if (err)
+                               goto out_brelse;
+                       ext4_update_dynamic_rev(sb);
+                       EXT4_SET_RO_COMPAT_FEATURE(sb,
                                        EXT4_FEATURE_RO_COMPAT_LARGE_FILE);
-                               sb->s_dirt = 1;
-                               handle->h_sync = 1;
-                               err = ext4_journal_dirty_metadata(handle,
-                                               EXT4_SB(sb)->s_sbh);
-                       }
+                       sb->s_dirt = 1;
+                       handle->h_sync = 1;
+                       err = ext4_journal_dirty_metadata(handle,
+                                       EXT4_SB(sb)->s_sbh);
                }
        }
        raw_inode->i_generation = cpu_to_le32(inode->i_generation);
@@ -2903,8 +2971,14 @@ static int ext4_do_update_inode(handle_t *handle,
        } else for (block = 0; block < EXT4_N_BLOCKS; block++)
                raw_inode->i_block[block] = ei->i_data[block];
 
-       if (ei->i_extra_isize)
+       raw_inode->i_disk_version = cpu_to_le32(inode->i_version);
+       if (ei->i_extra_isize) {
+               if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
+                       raw_inode->i_version_hi =
+                       cpu_to_le32(inode->i_version >> 32);
                raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
+       }
+
 
        BUFFER_TRACE(bh, "call ext4_journal_dirty_metadata");
        rc = ext4_journal_dirty_metadata(handle, bh);
@@ -3024,6 +3098,17 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
                ext4_journal_stop(handle);
        }
 
+       if (attr->ia_valid & ATTR_SIZE) {
+               if (!(EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) {
+                       struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
+
+                       if (attr->ia_size > sbi->s_bitmap_maxbytes) {
+                               error = -EFBIG;
+                               goto err_out;
+                       }
+               }
+       }
+
        if (S_ISREG(inode->i_mode) &&
            attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
                handle_t *handle;
@@ -3120,6 +3205,9 @@ int ext4_mark_iloc_dirty(handle_t *handle,
 {
        int err = 0;
 
+       if (test_opt(inode->i_sb, I_VERSION))
+               inode_inc_iversion(inode);
+
        /* the do_update_inode consumes one bh->b_count */
        get_bh(iloc->bh);
 
@@ -3158,8 +3246,10 @@ ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
  * Expand an inode by new_extra_isize bytes.
  * Returns 0 on success or negative error number on failure.
  */
-int ext4_expand_extra_isize(struct inode *inode, unsigned int new_extra_isize,
-                       struct ext4_iloc iloc, handle_t *handle)
+static int ext4_expand_extra_isize(struct inode *inode,
+                                  unsigned int new_extra_isize,
+                                  struct ext4_iloc iloc,
+                                  handle_t *handle)
 {
        struct ext4_inode *raw_inode;
        struct ext4_xattr_ibody_header *header;
index e7f894bdb4202359974088ba5c1f14585a43fc03..2ed7c37f897e79f0b9c6d6af3a5c2aad79fa7f59 100644 (file)
@@ -199,7 +199,7 @@ flags_err:
                 * need to allocate reservation structure for this inode
                 * before set the window size
                 */
-               mutex_lock(&ei->truncate_mutex);
+               down_write(&ei->i_data_sem);
                if (!ei->i_block_alloc_info)
                        ext4_init_block_alloc_info(inode);
 
@@ -207,7 +207,7 @@ flags_err:
                        struct ext4_reserve_window_node *rsv = &ei->i_block_alloc_info->rsv_window_node;
                        rsv->rsv_goal_size = rsv_window_size;
                }
-               mutex_unlock(&ei->truncate_mutex);
+               up_write(&ei->i_data_sem);
                return 0;
        }
        case EXT4_IOC_GROUP_EXTEND: {
@@ -254,6 +254,9 @@ flags_err:
                return err;
        }
 
+       case EXT4_IOC_MIGRATE:
+               return ext4_ext_migrate(inode, filp, cmd, arg);
+
        default:
                return -ENOTTY;
        }
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
new file mode 100644 (file)
index 0000000..76e5fed
--- /dev/null
@@ -0,0 +1,4552 @@
+/*
+ * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
+ * Written by Alex Tomas <alex@clusterfs.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public Licens
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
+ */
+
+
+/*
+ * mballoc.c contains the multiblocks allocation routines
+ */
+
+#include <linux/time.h>
+#include <linux/fs.h>
+#include <linux/namei.h>
+#include <linux/ext4_jbd2.h>
+#include <linux/ext4_fs.h>
+#include <linux/quotaops.h>
+#include <linux/buffer_head.h>
+#include <linux/module.h>
+#include <linux/swap.h>
+#include <linux/proc_fs.h>
+#include <linux/pagemap.h>
+#include <linux/seq_file.h>
+#include <linux/version.h>
+#include "group.h"
+
+/*
+ * MUSTDO:
+ *   - test ext4_ext_search_left() and ext4_ext_search_right()
+ *   - search for metadata in few groups
+ *
+ * TODO v4:
+ *   - normalization should take into account whether file is still open
+ *   - discard preallocations if no free space left (policy?)
+ *   - don't normalize tails
+ *   - quota
+ *   - reservation for superuser
+ *
+ * TODO v3:
+ *   - bitmap read-ahead (proposed by Oleg Drokin aka green)
+ *   - track min/max extents in each group for better group selection
+ *   - mb_mark_used() may allocate chunk right after splitting buddy
+ *   - tree of groups sorted by number of free blocks
+ *   - error handling
+ */
+
+/*
+ * The allocation request involve request for multiple number of blocks
+ * near to the goal(block) value specified.
+ *
+ * During initialization phase of the allocator we decide to use the group
+ * preallocation or inode preallocation depending on the size file. The
+ * size of the file could be the resulting file size we would have after
+ * allocation or the current file size which ever is larger. If the size is
+ * less that sbi->s_mb_stream_request we select the group
+ * preallocation. The default value of s_mb_stream_request is 16
+ * blocks. This can also be tuned via
+ * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
+ * of number of blocks.
+ *
+ * The main motivation for having small file use group preallocation is to
+ * ensure that we have small file closer in the disk.
+ *
+ * First stage the allocator looks at the inode prealloc list
+ * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
+ * this particular inode. The inode prealloc space is represented as:
+ *
+ * pa_lstart -> the logical start block for this prealloc space
+ * pa_pstart -> the physical start block for this prealloc space
+ * pa_len    -> lenght for this prealloc space
+ * pa_free   ->  free space available in this prealloc space
+ *
+ * The inode preallocation space is used looking at the _logical_ start
+ * block. If only the logical file block falls within the range of prealloc
+ * space we will consume the particular prealloc space. This make sure that
+ * that the we have contiguous physical blocks representing the file blocks
+ *
+ * The important thing to be noted in case of inode prealloc space is that
+ * we don't modify the values associated to inode prealloc space except
+ * pa_free.
+ *
+ * If we are not able to find blocks in the inode prealloc space and if we
+ * have the group allocation flag set then we look at the locality group
+ * prealloc space. These are per CPU prealloc list repreasented as
+ *
+ * ext4_sb_info.s_locality_groups[smp_processor_id()]
+ *
+ * The reason for having a per cpu locality group is to reduce the contention
+ * between CPUs. It is possible to get scheduled at this point.
+ *
+ * The locality group prealloc space is used looking at whether we have
+ * enough free space (pa_free) withing the prealloc space.
+ *
+ * If we can't allocate blocks via inode prealloc or/and locality group
+ * prealloc then we look at the buddy cache. The buddy cache is represented
+ * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
+ * mapped to the buddy and bitmap information regarding different
+ * groups. The buddy information is attached to buddy cache inode so that
+ * we can access them through the page cache. The information regarding
+ * each group is loaded via ext4_mb_load_buddy.  The information involve
+ * block bitmap and buddy information. The information are stored in the
+ * inode as:
+ *
+ *  {                        page                        }
+ *  [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
+ *
+ *
+ * one block each for bitmap and buddy information.  So for each group we
+ * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
+ * blocksize) blocks.  So it can have information regarding groups_per_page
+ * which is blocks_per_page/2
+ *
+ * The buddy cache inode is not stored on disk. The inode is thrown
+ * away when the filesystem is unmounted.
+ *
+ * We look for count number of blocks in the buddy cache. If we were able
+ * to locate that many free blocks we return with additional information
+ * regarding rest of the contiguous physical block available
+ *
+ * Before allocating blocks via buddy cache we normalize the request
+ * blocks. This ensure we ask for more blocks that we needed. The extra
+ * blocks that we get after allocation is added to the respective prealloc
+ * list. In case of inode preallocation we follow a list of heuristics
+ * based on file size. This can be found in ext4_mb_normalize_request. If
+ * we are doing a group prealloc we try to normalize the request to
+ * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
+ * 512 blocks. This can be tuned via
+ * /proc/fs/ext4/<partition/group_prealloc. The value is represented in
+ * terms of number of blocks. If we have mounted the file system with -O
+ * stripe=<value> option the group prealloc request is normalized to the
+ * stripe value (sbi->s_stripe)
+ *
+ * The regular allocator(using the buddy cache) support few tunables.
+ *
+ * /proc/fs/ext4/<partition>/min_to_scan
+ * /proc/fs/ext4/<partition>/max_to_scan
+ * /proc/fs/ext4/<partition>/order2_req
+ *
+ * The regular allocator use buddy scan only if the request len is power of
+ * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
+ * value of s_mb_order2_reqs can be tuned via
+ * /proc/fs/ext4/<partition>/order2_req.  If the request len is equal to
+ * stripe size (sbi->s_stripe), we try to search for contigous block in
+ * stripe size. This should result in better allocation on RAID setup. If
+ * not we search in the specific group using bitmap for best extents. The
+ * tunable min_to_scan and max_to_scan controll the behaviour here.
+ * min_to_scan indicate how long the mballoc __must__ look for a best
+ * extent and max_to_scanindicate how long the mballoc __can__ look for a
+ * best extent in the found extents. Searching for the blocks starts with
+ * the group specified as the goal value in allocation context via
+ * ac_g_ex. Each group is first checked based on the criteria whether it
+ * can used for allocation. ext4_mb_good_group explains how the groups are
+ * checked.
+ *
+ * Both the prealloc space are getting populated as above. So for the first
+ * request we will hit the buddy cache which will result in this prealloc
+ * space getting filled. The prealloc space is then later used for the
+ * subsequent request.
+ */
+
+/*
+ * mballoc operates on the following data:
+ *  - on-disk bitmap
+ *  - in-core buddy (actually includes buddy and bitmap)
+ *  - preallocation descriptors (PAs)
+ *
+ * there are two types of preallocations:
+ *  - inode
+ *    assiged to specific inode and can be used for this inode only.
+ *    it describes part of inode's space preallocated to specific
+ *    physical blocks. any block from that preallocated can be used
+ *    independent. the descriptor just tracks number of blocks left
+ *    unused. so, before taking some block from descriptor, one must
+ *    make sure corresponded logical block isn't allocated yet. this
+ *    also means that freeing any block within descriptor's range
+ *    must discard all preallocated blocks.
+ *  - locality group
+ *    assigned to specific locality group which does not translate to
+ *    permanent set of inodes: inode can join and leave group. space
+ *    from this type of preallocation can be used for any inode. thus
+ *    it's consumed from the beginning to the end.
+ *
+ * relation between them can be expressed as:
+ *    in-core buddy = on-disk bitmap + preallocation descriptors
+ *
+ * this mean blocks mballoc considers used are:
+ *  - allocated blocks (persistent)
+ *  - preallocated blocks (non-persistent)
+ *
+ * consistency in mballoc world means that at any time a block is either
+ * free or used in ALL structures. notice: "any time" should not be read
+ * literally -- time is discrete and delimited by locks.
+ *
+ *  to keep it simple, we don't use block numbers, instead we count number of
+ *  blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
+ *
+ * all operations can be expressed as:
+ *  - init buddy:                      buddy = on-disk + PAs
+ *  - new PA:                          buddy += N; PA = N
+ *  - use inode PA:                    on-disk += N; PA -= N
+ *  - discard inode PA                 buddy -= on-disk - PA; PA = 0
+ *  - use locality group PA            on-disk += N; PA -= N
+ *  - discard locality group PA                buddy -= PA; PA = 0
+ *  note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
+ *        is used in real operation because we can't know actual used
+ *        bits from PA, only from on-disk bitmap
+ *
+ * if we follow this strict logic, then all operations above should be atomic.
+ * given some of them can block, we'd have to use something like semaphores
+ * killing performance on high-end SMP hardware. let's try to relax it using
+ * the following knowledge:
+ *  1) if buddy is referenced, it's already initialized
+ *  2) while block is used in buddy and the buddy is referenced,
+ *     nobody can re-allocate that block
+ *  3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
+ *     bit set and PA claims same block, it's OK. IOW, one can set bit in
+ *     on-disk bitmap if buddy has same bit set or/and PA covers corresponded
+ *     block
+ *
+ * so, now we're building a concurrency table:
+ *  - init buddy vs.
+ *    - new PA
+ *      blocks for PA are allocated in the buddy, buddy must be referenced
+ *      until PA is linked to allocation group to avoid concurrent buddy init
+ *    - use inode PA
+ *      we need to make sure that either on-disk bitmap or PA has uptodate data
+ *      given (3) we care that PA-=N operation doesn't interfere with init
+ *    - discard inode PA
+ *      the simplest way would be to have buddy initialized by the discard
+ *    - use locality group PA
+ *      again PA-=N must be serialized with init
+ *    - discard locality group PA
+ *      the simplest way would be to have buddy initialized by the discard
+ *  - new PA vs.
+ *    - use inode PA
+ *      i_data_sem serializes them
+ *    - discard inode PA
+ *      discard process must wait until PA isn't used by another process
+ *    - use locality group PA
+ *      some mutex should serialize them
+ *    - discard locality group PA
+ *      discard process must wait until PA isn't used by another process
+ *  - use inode PA
+ *    - use inode PA
+ *      i_data_sem or another mutex should serializes them
+ *    - discard inode PA
+ *      discard process must wait until PA isn't used by another process
+ *    - use locality group PA
+ *      nothing wrong here -- they're different PAs covering different blocks
+ *    - discard locality group PA
+ *      discard process must wait until PA isn't used by another process
+ *
+ * now we're ready to make few consequences:
+ *  - PA is referenced and while it is no discard is possible
+ *  - PA is referenced until block isn't marked in on-disk bitmap
+ *  - PA changes only after on-disk bitmap
+ *  - discard must not compete with init. either init is done before
+ *    any discard or they're serialized somehow
+ *  - buddy init as sum of on-disk bitmap and PAs is done atomically
+ *
+ * a special case when we've used PA to emptiness. no need to modify buddy
+ * in this case, but we should care about concurrent init
+ *
+ */
+
+ /*
+ * Logic in few words:
+ *
+ *  - allocation:
+ *    load group
+ *    find blocks
+ *    mark bits in on-disk bitmap
+ *    release group
+ *
+ *  - use preallocation:
+ *    find proper PA (per-inode or group)
+ *    load group
+ *    mark bits in on-disk bitmap
+ *    release group
+ *    release PA
+ *
+ *  - free:
+ *    load group
+ *    mark bits in on-disk bitmap
+ *    release group
+ *
+ *  - discard preallocations in group:
+ *    mark PAs deleted
+ *    move them onto local list
+ *    load on-disk bitmap
+ *    load group
+ *    remove PA from object (inode or locality group)
+ *    mark free blocks in-core
+ *
+ *  - discard inode's preallocations:
+ */
+
+/*
+ * Locking rules
+ *
+ * Locks:
+ *  - bitlock on a group       (group)
+ *  - object (inode/locality)  (object)
+ *  - per-pa lock              (pa)
+ *
+ * Paths:
+ *  - new pa
+ *    object
+ *    group
+ *
+ *  - find and use pa:
+ *    pa
+ *
+ *  - release consumed pa:
+ *    pa
+ *    group
+ *    object
+ *
+ *  - generate in-core bitmap:
+ *    group
+ *        pa
+ *
+ *  - discard all for given object (inode, locality group):
+ *    object
+ *        pa
+ *    group
+ *
+ *  - discard all for given group:
+ *    group
+ *        pa
+ *    group
+ *        object
+ *
+ */
+
+/*
+ * with AGGRESSIVE_CHECK allocator runs consistency checks over
+ * structures. these checks slow things down a lot
+ */
+#define AGGRESSIVE_CHECK__
+
+/*
+ * with DOUBLE_CHECK defined mballoc creates persistent in-core
+ * bitmaps, maintains and uses them to check for double allocations
+ */
+#define DOUBLE_CHECK__
+
+/*
+ */
+#define MB_DEBUG__
+#ifdef MB_DEBUG
+#define mb_debug(fmt, a...)    printk(fmt, ##a)
+#else
+#define mb_debug(fmt, a...)
+#endif
+
+/*
+ * with EXT4_MB_HISTORY mballoc stores last N allocations in memory
+ * and you can monitor it in /proc/fs/ext4/<dev>/mb_history
+ */
+#define EXT4_MB_HISTORY
+#define EXT4_MB_HISTORY_ALLOC          1       /* allocation */
+#define EXT4_MB_HISTORY_PREALLOC       2       /* preallocated blocks used */
+#define EXT4_MB_HISTORY_DISCARD                4       /* preallocation discarded */
+#define EXT4_MB_HISTORY_FREE           8       /* free */
+
+#define EXT4_MB_HISTORY_DEFAULT                (EXT4_MB_HISTORY_ALLOC | \
+                                        EXT4_MB_HISTORY_PREALLOC)
+
+/*
+ * How long mballoc can look for a best extent (in found extents)
+ */
+#define MB_DEFAULT_MAX_TO_SCAN         200
+
+/*
+ * How long mballoc must look for a best extent
+ */
+#define MB_DEFAULT_MIN_TO_SCAN         10
+
+/*
+ * How many groups mballoc will scan looking for the best chunk
+ */
+#define MB_DEFAULT_MAX_GROUPS_TO_SCAN  5
+
+/*
+ * with 'ext4_mb_stats' allocator will collect stats that will be
+ * shown at umount. The collecting costs though!
+ */
+#define MB_DEFAULT_STATS               1
+
+/*
+ * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
+ * by the stream allocator, which purpose is to pack requests
+ * as close each to other as possible to produce smooth I/O traffic
+ * We use locality group prealloc space for stream request.
+ * We can tune the same via /proc/fs/ext4/<parition>/stream_req
+ */
+#define MB_DEFAULT_STREAM_THRESHOLD    16      /* 64K */
+
+/*
+ * for which requests use 2^N search using buddies
+ */
+#define MB_DEFAULT_ORDER2_REQS         2
+
+/*
+ * default group prealloc size 512 blocks
+ */
+#define MB_DEFAULT_GROUP_PREALLOC      512
+
+static struct kmem_cache *ext4_pspace_cachep;
+
+#ifdef EXT4_BB_MAX_BLOCKS
+#undef EXT4_BB_MAX_BLOCKS
+#endif
+#define EXT4_BB_MAX_BLOCKS     30
+
+struct ext4_free_metadata {
+       ext4_group_t group;
+       unsigned short num;
+       ext4_grpblk_t  blocks[EXT4_BB_MAX_BLOCKS];
+       struct list_head list;
+};
+
+struct ext4_group_info {
+       unsigned long   bb_state;
+       unsigned long   bb_tid;
+       struct ext4_free_metadata *bb_md_cur;
+       unsigned short  bb_first_free;
+       unsigned short  bb_free;
+       unsigned short  bb_fragments;
+       struct          list_head bb_prealloc_list;
+#ifdef DOUBLE_CHECK
+       void            *bb_bitmap;
+#endif
+       unsigned short  bb_counters[];
+};
+
+#define EXT4_GROUP_INFO_NEED_INIT_BIT  0
+#define EXT4_GROUP_INFO_LOCKED_BIT     1
+
+#define EXT4_MB_GRP_NEED_INIT(grp)     \
+       (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
+
+
+struct ext4_prealloc_space {
+       struct list_head        pa_inode_list;
+       struct list_head        pa_group_list;
+       union {
+               struct list_head pa_tmp_list;
+               struct rcu_head pa_rcu;
+       } u;
+       spinlock_t              pa_lock;
+       atomic_t                pa_count;
+       unsigned                pa_deleted;
+       ext4_fsblk_t            pa_pstart;      /* phys. block */
+       ext4_lblk_t             pa_lstart;      /* log. block */
+       unsigned short          pa_len;         /* len of preallocated chunk */
+       unsigned short          pa_free;        /* how many blocks are free */
+       unsigned short          pa_linear;      /* consumed in one direction
+                                                * strictly, for grp prealloc */
+       spinlock_t              *pa_obj_lock;
+       struct inode            *pa_inode;      /* hack, for history only */
+};
+
+
+struct ext4_free_extent {
+       ext4_lblk_t fe_logical;
+       ext4_grpblk_t fe_start;
+       ext4_group_t fe_group;
+       int fe_len;
+};
+
+/*
+ * Locality group:
+ *   we try to group all related changes together
+ *   so that writeback can flush/allocate them together as well
+ */
+struct ext4_locality_group {
+       /* for allocator */
+       struct mutex            lg_mutex;       /* to serialize allocates */
+       struct list_head        lg_prealloc_list;/* list of preallocations */
+       spinlock_t              lg_prealloc_lock;
+};
+
+struct ext4_allocation_context {
+       struct inode *ac_inode;
+       struct super_block *ac_sb;
+
+       /* original request */
+       struct ext4_free_extent ac_o_ex;
+
+       /* goal request (after normalization) */
+       struct ext4_free_extent ac_g_ex;
+
+       /* the best found extent */
+       struct ext4_free_extent ac_b_ex;
+
+       /* copy of the bext found extent taken before preallocation efforts */
+       struct ext4_free_extent ac_f_ex;
+
+       /* number of iterations done. we have to track to limit searching */
+       unsigned long ac_ex_scanned;
+       __u16 ac_groups_scanned;
+       __u16 ac_found;
+       __u16 ac_tail;
+       __u16 ac_buddy;
+       __u16 ac_flags;         /* allocation hints */
+       __u8 ac_status;
+       __u8 ac_criteria;
+       __u8 ac_repeats;
+       __u8 ac_2order;         /* if request is to allocate 2^N blocks and
+                                * N > 0, the field stores N, otherwise 0 */
+       __u8 ac_op;             /* operation, for history only */
+       struct page *ac_bitmap_page;
+       struct page *ac_buddy_page;
+       struct ext4_prealloc_space *ac_pa;
+       struct ext4_locality_group *ac_lg;
+};
+
+#define AC_STATUS_CONTINUE     1
+#define AC_STATUS_FOUND                2
+#define AC_STATUS_BREAK                3
+
+struct ext4_mb_history {
+       struct ext4_free_extent orig;   /* orig allocation */
+       struct ext4_free_extent goal;   /* goal allocation */
+       struct ext4_free_extent result; /* result allocation */
+       unsigned pid;
+       unsigned ino;
+       __u16 found;    /* how many extents have been found */
+       __u16 groups;   /* how many groups have been scanned */
+       __u16 tail;     /* what tail broke some buddy */
+       __u16 buddy;    /* buddy the tail ^^^ broke */
+       __u16 flags;
+       __u8 cr:3;      /* which phase the result extent was found at */
+       __u8 op:4;
+       __u8 merged:1;
+};
+
+struct ext4_buddy {
+       struct page *bd_buddy_page;
+       void *bd_buddy;
+       struct page *bd_bitmap_page;
+       void *bd_bitmap;
+       struct ext4_group_info *bd_info;
+       struct super_block *bd_sb;
+       __u16 bd_blkbits;
+       ext4_group_t bd_group;
+};
+#define EXT4_MB_BITMAP(e4b)    ((e4b)->bd_bitmap)
+#define EXT4_MB_BUDDY(e4b)     ((e4b)->bd_buddy)
+
+#ifndef EXT4_MB_HISTORY
+static inline void ext4_mb_store_history(struct ext4_allocation_context *ac)
+{
+       return;
+}
+#else
+static void ext4_mb_store_history(struct ext4_allocation_context *ac);
+#endif
+
+#define in_range(b, first, len)        ((b) >= (first) && (b) <= (first) + (len) - 1)
+
+static struct proc_dir_entry *proc_root_ext4;
+struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t);
+ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
+                       ext4_fsblk_t goal, unsigned long *count, int *errp);
+
+static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
+                                       ext4_group_t group);
+static void ext4_mb_poll_new_transaction(struct super_block *, handle_t *);
+static void ext4_mb_free_committed_blocks(struct super_block *);
+static void ext4_mb_return_to_preallocation(struct inode *inode,
+                                       struct ext4_buddy *e4b, sector_t block,
+                                       int count);
+static void ext4_mb_put_pa(struct ext4_allocation_context *,
+                       struct super_block *, struct ext4_prealloc_space *pa);
+static int ext4_mb_init_per_dev_proc(struct super_block *sb);
+static int ext4_mb_destroy_per_dev_proc(struct super_block *sb);
+
+
+static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
+{
+       struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
+
+       bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
+}
+
+static inline void ext4_unlock_group(struct super_block *sb,
+                                       ext4_group_t group)
+{
+       struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
+
+       bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
+}
+
+static inline int ext4_is_group_locked(struct super_block *sb,
+                                       ext4_group_t group)
+{
+       struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
+
+       return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT,
+                                               &(grinfo->bb_state));
+}
+
+static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
+                                       struct ext4_free_extent *fex)
+{
+       ext4_fsblk_t block;
+
+       block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
+                       + fex->fe_start
+                       + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+       return block;
+}
+
+#if BITS_PER_LONG == 64
+#define mb_correct_addr_and_bit(bit, addr)             \
+{                                                      \
+       bit += ((unsigned long) addr & 7UL) << 3;       \
+       addr = (void *) ((unsigned long) addr & ~7UL);  \
+}
+#elif BITS_PER_LONG == 32
+#define mb_correct_addr_and_bit(bit, addr)             \
+{                                                      \
+       bit += ((unsigned long) addr & 3UL) << 3;       \
+       addr = (void *) ((unsigned long) addr & ~3UL);  \
+}
+#else
+#error "how many bits you are?!"
+#endif
+
+static inline int mb_test_bit(int bit, void *addr)
+{
+       /*
+        * ext4_test_bit on architecture like powerpc
+        * needs unsigned long aligned address
+        */
+       mb_correct_addr_and_bit(bit, addr);
+       return ext4_test_bit(bit, addr);
+}
+
+static inline void mb_set_bit(int bit, void *addr)
+{
+       mb_correct_addr_and_bit(bit, addr);
+       ext4_set_bit(bit, addr);
+}
+
+static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
+{
+       mb_correct_addr_and_bit(bit, addr);
+       ext4_set_bit_atomic(lock, bit, addr);
+}
+
+static inline void mb_clear_bit(int bit, void *addr)
+{
+       mb_correct_addr_and_bit(bit, addr);
+       ext4_clear_bit(bit, addr);
+}
+
+static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
+{
+       mb_correct_addr_and_bit(bit, addr);
+       ext4_clear_bit_atomic(lock, bit, addr);
+}
+
+static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
+{
+       char *bb;
+
+       /* FIXME!! is this needed */
+       BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
+       BUG_ON(max == NULL);
+
+       if (order > e4b->bd_blkbits + 1) {
+               *max = 0;
+               return NULL;
+       }
+
+       /* at order 0 we see each particular block */
+       *max = 1 << (e4b->bd_blkbits + 3);
+       if (order == 0)
+               return EXT4_MB_BITMAP(e4b);
+
+       bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
+       *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
+
+       return bb;
+}
+
+#ifdef DOUBLE_CHECK
+static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
+                          int first, int count)
+{
+       int i;
+       struct super_block *sb = e4b->bd_sb;
+
+       if (unlikely(e4b->bd_info->bb_bitmap == NULL))
+               return;
+       BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
+       for (i = 0; i < count; i++) {
+               if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
+                       ext4_fsblk_t blocknr;
+                       blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
+                       blocknr += first + i;
+                       blocknr +=
+                           le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+
+                       ext4_error(sb, __FUNCTION__, "double-free of inode"
+                                  " %lu's block %llu(bit %u in group %lu)\n",
+                                  inode ? inode->i_ino : 0, blocknr,
+                                  first + i, e4b->bd_group);
+               }
+               mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
+       }
+}
+
+static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
+{
+       int i;
+
+       if (unlikely(e4b->bd_info->bb_bitmap == NULL))
+               return;
+       BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+       for (i = 0; i < count; i++) {
+               BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
+               mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
+       }
+}
+
+static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
+{
+       if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
+               unsigned char *b1, *b2;
+               int i;
+               b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
+               b2 = (unsigned char *) bitmap;
+               for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
+                       if (b1[i] != b2[i]) {
+                               printk("corruption in group %lu at byte %u(%u):"
+                                      " %x in copy != %x on disk/prealloc\n",
+                                       e4b->bd_group, i, i * 8, b1[i], b2[i]);
+                               BUG();
+                       }
+               }
+       }
+}
+
+#else
+static inline void mb_free_blocks_double(struct inode *inode,
+                               struct ext4_buddy *e4b, int first, int count)
+{
+       return;
+}
+static inline void mb_mark_used_double(struct ext4_buddy *e4b,
+                                               int first, int count)
+{
+       return;
+}
+static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
+{
+       return;
+}
+#endif
+
+#ifdef AGGRESSIVE_CHECK
+
+#define MB_CHECK_ASSERT(assert)                                                \
+do {                                                                   \
+       if (!(assert)) {                                                \
+               printk(KERN_EMERG                                       \
+                       "Assertion failure in %s() at %s:%d: \"%s\"\n", \
+                       function, file, line, # assert);                \
+               BUG();                                                  \
+       }                                                               \
+} while (0)
+
+static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
+                               const char *function, int line)
+{
+       struct super_block *sb = e4b->bd_sb;
+       int order = e4b->bd_blkbits + 1;
+       int max;
+       int max2;
+       int i;
+       int j;
+       int k;
+       int count;
+       struct ext4_group_info *grp;
+       int fragments = 0;
+       int fstart;
+       struct list_head *cur;
+       void *buddy;
+       void *buddy2;
+
+       if (!test_opt(sb, MBALLOC))
+               return 0;
+
+       {
+               static int mb_check_counter;
+               if (mb_check_counter++ % 100 != 0)
+                       return 0;
+       }
+
+       while (order > 1) {
+               buddy = mb_find_buddy(e4b, order, &max);
+               MB_CHECK_ASSERT(buddy);
+               buddy2 = mb_find_buddy(e4b, order - 1, &max2);
+               MB_CHECK_ASSERT(buddy2);
+               MB_CHECK_ASSERT(buddy != buddy2);
+               MB_CHECK_ASSERT(max * 2 == max2);
+
+               count = 0;
+               for (i = 0; i < max; i++) {
+
+                       if (mb_test_bit(i, buddy)) {
+                               /* only single bit in buddy2 may be 1 */
+                               if (!mb_test_bit(i << 1, buddy2)) {
+                                       MB_CHECK_ASSERT(
+                                               mb_test_bit((i<<1)+1, buddy2));
+                               } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
+                                       MB_CHECK_ASSERT(
+                                               mb_test_bit(i << 1, buddy2));
+                               }
+                               continue;
+                       }
+
+                       /* both bits in buddy2 must be 0 */
+                       MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
+                       MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
+
+                       for (j = 0; j < (1 << order); j++) {
+                               k = (i * (1 << order)) + j;
+                               MB_CHECK_ASSERT(
+                                       !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
+                       }
+                       count++;
+               }
+               MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
+               order--;
+       }
+
+       fstart = -1;
+       buddy = mb_find_buddy(e4b, 0, &max);
+       for (i = 0; i < max; i++) {
+               if (!mb_test_bit(i, buddy)) {
+                       MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
+                       if (fstart == -1) {
+                               fragments++;
+                               fstart = i;
+                       }
+                       continue;
+               }
+               fstart = -1;
+               /* check used bits only */
+               for (j = 0; j < e4b->bd_blkbits + 1; j++) {
+                       buddy2 = mb_find_buddy(e4b, j, &max2);
+                       k = i >> j;
+                       MB_CHECK_ASSERT(k < max2);
+                       MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
+               }
+       }
+       MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
+       MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
+
+       grp = ext4_get_group_info(sb, e4b->bd_group);
+       buddy = mb_find_buddy(e4b, 0, &max);
+       list_for_each(cur, &grp->bb_prealloc_list) {
+               ext4_group_t groupnr;
+               struct ext4_prealloc_space *pa;
+               pa = list_entry(cur, struct ext4_prealloc_space, group_list);
+               ext4_get_group_no_and_offset(sb, pa->pstart, &groupnr, &k);
+               MB_CHECK_ASSERT(groupnr == e4b->bd_group);
+               for (i = 0; i < pa->len; i++)
+                       MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
+       }
+       return 0;
+}
+#undef MB_CHECK_ASSERT
+#define mb_check_buddy(e4b) __mb_check_buddy(e4b,      \
+                                       __FILE__, __FUNCTION__, __LINE__)
+#else
+#define mb_check_buddy(e4b)
+#endif
+
+/* FIXME!! need more doc */
+static void ext4_mb_mark_free_simple(struct super_block *sb,
+                               void *buddy, unsigned first, int len,
+                                       struct ext4_group_info *grp)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       unsigned short min;
+       unsigned short max;
+       unsigned short chunk;
+       unsigned short border;
+
+       BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb));
+
+       border = 2 << sb->s_blocksize_bits;
+
+       while (len > 0) {
+               /* find how many blocks can be covered since this position */
+               max = ffs(first | border) - 1;
+
+               /* find how many blocks of power 2 we need to mark */
+               min = fls(len) - 1;
+
+               if (max < min)
+                       min = max;
+               chunk = 1 << min;
+
+               /* mark multiblock chunks only */
+               grp->bb_counters[min]++;
+               if (min > 0)
+                       mb_clear_bit(first >> min,
+                                    buddy + sbi->s_mb_offsets[min]);
+
+               len -= chunk;
+               first += chunk;
+       }
+}
+
+static void ext4_mb_generate_buddy(struct super_block *sb,
+                               void *buddy, void *bitmap, ext4_group_t group)
+{
+       struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+       unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
+       unsigned short i = 0;
+       unsigned short first;
+       unsigned short len;
+       unsigned free = 0;
+       unsigned fragments = 0;
+       unsigned long long period = get_cycles();
+
+       /* initialize buddy from bitmap which is aggregation
+        * of on-disk bitmap and preallocations */
+       i = ext4_find_next_zero_bit(bitmap, max, 0);
+       grp->bb_first_free = i;
+       while (i < max) {
+               fragments++;
+               first = i;
+               i = ext4_find_next_bit(bitmap, max, i);
+               len = i - first;
+               free += len;
+               if (len > 1)
+                       ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
+               else
+                       grp->bb_counters[0]++;
+               if (i < max)
+                       i = ext4_find_next_zero_bit(bitmap, max, i);
+       }
+       grp->bb_fragments = fragments;
+
+       if (free != grp->bb_free) {
+               printk(KERN_DEBUG
+                       "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
+                       group, free, grp->bb_free);
+               grp->bb_free = free;
+       }
+
+       clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
+
+       period = get_cycles() - period;
+       spin_lock(&EXT4_SB(sb)->s_bal_lock);
+       EXT4_SB(sb)->s_mb_buddies_generated++;
+       EXT4_SB(sb)->s_mb_generation_time += period;
+       spin_unlock(&EXT4_SB(sb)->s_bal_lock);
+}
+
+/* The buddy information is attached the buddy cache inode
+ * for convenience. The information regarding each group
+ * is loaded via ext4_mb_load_buddy. The information involve
+ * block bitmap and buddy information. The information are
+ * stored in the inode as
+ *
+ * {                        page                        }
+ * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
+ *
+ *
+ * one block each for bitmap and buddy information.
+ * So for each group we take up 2 blocks. A page can
+ * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize)  blocks.
+ * So it can have information regarding groups_per_page which
+ * is blocks_per_page/2
+ */
+
+static int ext4_mb_init_cache(struct page *page, char *incore)
+{
+       int blocksize;
+       int blocks_per_page;
+       int groups_per_page;
+       int err = 0;
+       int i;
+       ext4_group_t first_group;
+       int first_block;
+       struct super_block *sb;
+       struct buffer_head *bhs;
+       struct buffer_head **bh;
+       struct inode *inode;
+       char *data;
+       char *bitmap;
+
+       mb_debug("init page %lu\n", page->index);
+
+       inode = page->mapping->host;
+       sb = inode->i_sb;
+       blocksize = 1 << inode->i_blkbits;
+       blocks_per_page = PAGE_CACHE_SIZE / blocksize;
+
+       groups_per_page = blocks_per_page >> 1;
+       if (groups_per_page == 0)
+               groups_per_page = 1;
+
+       /* allocate buffer_heads to read bitmaps */
+       if (groups_per_page > 1) {
+               err = -ENOMEM;
+               i = sizeof(struct buffer_head *) * groups_per_page;
+               bh = kzalloc(i, GFP_NOFS);
+               if (bh == NULL)
+                       goto out;
+       } else
+               bh = &bhs;
+
+       first_group = page->index * blocks_per_page / 2;
+
+       /* read all groups the page covers into the cache */
+       for (i = 0; i < groups_per_page; i++) {
+               struct ext4_group_desc *desc;
+
+               if (first_group + i >= EXT4_SB(sb)->s_groups_count)
+                       break;
+
+               err = -EIO;
+               desc = ext4_get_group_desc(sb, first_group + i, NULL);
+               if (desc == NULL)
+                       goto out;
+
+               err = -ENOMEM;
+               bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
+               if (bh[i] == NULL)
+                       goto out;
+
+               if (bh_uptodate_or_lock(bh[i]))
+                       continue;
+
+               if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+                       ext4_init_block_bitmap(sb, bh[i],
+                                               first_group + i, desc);
+                       set_buffer_uptodate(bh[i]);
+                       unlock_buffer(bh[i]);
+                       continue;
+               }
+               get_bh(bh[i]);
+               bh[i]->b_end_io = end_buffer_read_sync;
+               submit_bh(READ, bh[i]);
+               mb_debug("read bitmap for group %lu\n", first_group + i);
+       }
+
+       /* wait for I/O completion */
+       for (i = 0; i < groups_per_page && bh[i]; i++)
+               wait_on_buffer(bh[i]);
+
+       err = -EIO;
+       for (i = 0; i < groups_per_page && bh[i]; i++)
+               if (!buffer_uptodate(bh[i]))
+                       goto out;
+
+       first_block = page->index * blocks_per_page;
+       for (i = 0; i < blocks_per_page; i++) {
+               int group;
+               struct ext4_group_info *grinfo;
+
+               group = (first_block + i) >> 1;
+               if (group >= EXT4_SB(sb)->s_groups_count)
+                       break;
+
+               /*
+                * data carry information regarding this
+                * particular group in the format specified
+                * above
+                *
+                */
+               data = page_address(page) + (i * blocksize);
+               bitmap = bh[group - first_group]->b_data;
+
+               /*
+                * We place the buddy block and bitmap block
+                * close together
+                */
+               if ((first_block + i) & 1) {
+                       /* this is block of buddy */
+                       BUG_ON(incore == NULL);
+                       mb_debug("put buddy for group %u in page %lu/%x\n",
+                               group, page->index, i * blocksize);
+                       memset(data, 0xff, blocksize);
+                       grinfo = ext4_get_group_info(sb, group);
+                       grinfo->bb_fragments = 0;
+                       memset(grinfo->bb_counters, 0,
+                              sizeof(unsigned short)*(sb->s_blocksize_bits+2));
+                       /*
+                        * incore got set to the group block bitmap below
+                        */
+                       ext4_mb_generate_buddy(sb, data, incore, group);
+                       incore = NULL;
+               } else {
+                       /* this is block of bitmap */
+                       BUG_ON(incore != NULL);
+                       mb_debug("put bitmap for group %u in page %lu/%x\n",
+                               group, page->index, i * blocksize);
+
+                       /* see comments in ext4_mb_put_pa() */
+                       ext4_lock_group(sb, group);
+                       memcpy(data, bitmap, blocksize);
+
+                       /* mark all preallocated blks used in in-core bitmap */
+                       ext4_mb_generate_from_pa(sb, data, group);
+                       ext4_unlock_group(sb, group);
+
+                       /* set incore so that the buddy information can be
+                        * generated using this
+                        */
+                       incore = data;
+               }
+       }
+       SetPageUptodate(page);
+
+out:
+       if (bh) {
+               for (i = 0; i < groups_per_page && bh[i]; i++)
+                       brelse(bh[i]);
+               if (bh != &bhs)
+                       kfree(bh);
+       }
+       return err;
+}
+
+static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
+               struct ext4_buddy *e4b)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       struct inode *inode = sbi->s_buddy_cache;
+       int blocks_per_page;
+       int block;
+       int pnum;
+       int poff;
+       struct page *page;
+
+       mb_debug("load group %lu\n", group);
+
+       blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
+
+       e4b->bd_blkbits = sb->s_blocksize_bits;
+       e4b->bd_info = ext4_get_group_info(sb, group);
+       e4b->bd_sb = sb;
+       e4b->bd_group = group;
+       e4b->bd_buddy_page = NULL;
+       e4b->bd_bitmap_page = NULL;
+
+       /*
+        * the buddy cache inode stores the block bitmap
+        * and buddy information in consecutive blocks.
+        * So for each group we need two blocks.
+        */
+       block = group * 2;
+       pnum = block / blocks_per_page;
+       poff = block % blocks_per_page;
+
+       /* we could use find_or_create_page(), but it locks page
+        * what we'd like to avoid in fast path ... */
+       page = find_get_page(inode->i_mapping, pnum);
+       if (page == NULL || !PageUptodate(page)) {
+               if (page)
+                       page_cache_release(page);
+               page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
+               if (page) {
+                       BUG_ON(page->mapping != inode->i_mapping);
+                       if (!PageUptodate(page)) {
+                               ext4_mb_init_cache(page, NULL);
+                               mb_cmp_bitmaps(e4b, page_address(page) +
+                                              (poff * sb->s_blocksize));
+                       }
+                       unlock_page(page);
+               }
+       }
+       if (page == NULL || !PageUptodate(page))
+               goto err;
+       e4b->bd_bitmap_page = page;
+       e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
+       mark_page_accessed(page);
+
+       block++;
+       pnum = block / blocks_per_page;
+       poff = block % blocks_per_page;
+
+       page = find_get_page(inode->i_mapping, pnum);
+       if (page == NULL || !PageUptodate(page)) {
+               if (page)
+                       page_cache_release(page);
+               page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
+               if (page) {
+                       BUG_ON(page->mapping != inode->i_mapping);
+                       if (!PageUptodate(page))
+                               ext4_mb_init_cache(page, e4b->bd_bitmap);
+
+                       unlock_page(page);
+               }
+       }
+       if (page == NULL || !PageUptodate(page))
+               goto err;
+       e4b->bd_buddy_page = page;
+       e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
+       mark_page_accessed(page);
+
+       BUG_ON(e4b->bd_bitmap_page == NULL);
+       BUG_ON(e4b->bd_buddy_page == NULL);
+
+       return 0;
+
+err:
+       if (e4b->bd_bitmap_page)
+               page_cache_release(e4b->bd_bitmap_page);
+       if (e4b->bd_buddy_page)
+               page_cache_release(e4b->bd_buddy_page);
+       e4b->bd_buddy = NULL;
+       e4b->bd_bitmap = NULL;
+       return -EIO;
+}
+
+static void ext4_mb_release_desc(struct ext4_buddy *e4b)
+{
+       if (e4b->bd_bitmap_page)
+               page_cache_release(e4b->bd_bitmap_page);
+       if (e4b->bd_buddy_page)
+               page_cache_release(e4b->bd_buddy_page);
+}
+
+
+static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
+{
+       int order = 1;
+       void *bb;
+
+       BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
+       BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
+
+       bb = EXT4_MB_BUDDY(e4b);
+       while (order <= e4b->bd_blkbits + 1) {
+               block = block >> 1;
+               if (!mb_test_bit(block, bb)) {
+                       /* this block is part of buddy of order 'order' */
+                       return order;
+               }
+               bb += 1 << (e4b->bd_blkbits - order);
+               order++;
+       }
+       return 0;
+}
+
+static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
+{
+       __u32 *addr;
+
+       len = cur + len;
+       while (cur < len) {
+               if ((cur & 31) == 0 && (len - cur) >= 32) {
+                       /* fast path: clear whole word at once */
+                       addr = bm + (cur >> 3);
+                       *addr = 0;
+                       cur += 32;
+                       continue;
+               }
+               mb_clear_bit_atomic(lock, cur, bm);
+               cur++;
+       }
+}
+
+static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
+{
+       __u32 *addr;
+
+       len = cur + len;
+       while (cur < len) {
+               if ((cur & 31) == 0 && (len - cur) >= 32) {
+                       /* fast path: set whole word at once */
+                       addr = bm + (cur >> 3);
+                       *addr = 0xffffffff;
+                       cur += 32;
+                       continue;
+               }
+               mb_set_bit_atomic(lock, cur, bm);
+               cur++;
+       }
+}
+
+static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
+                         int first, int count)
+{
+       int block = 0;
+       int max = 0;
+       int order;
+       void *buddy;
+       void *buddy2;
+       struct super_block *sb = e4b->bd_sb;
+
+       BUG_ON(first + count > (sb->s_blocksize << 3));
+       BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
+       mb_check_buddy(e4b);
+       mb_free_blocks_double(inode, e4b, first, count);
+
+       e4b->bd_info->bb_free += count;
+       if (first < e4b->bd_info->bb_first_free)
+               e4b->bd_info->bb_first_free = first;
+
+       /* let's maintain fragments counter */
+       if (first != 0)
+               block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
+       if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
+               max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
+       if (block && max)
+               e4b->bd_info->bb_fragments--;
+       else if (!block && !max)
+               e4b->bd_info->bb_fragments++;
+
+       /* let's maintain buddy itself */
+       while (count-- > 0) {
+               block = first++;
+               order = 0;
+
+               if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
+                       ext4_fsblk_t blocknr;
+                       blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
+                       blocknr += block;
+                       blocknr +=
+                           le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
+
+                       ext4_error(sb, __FUNCTION__, "double-free of inode"
+                                  " %lu's block %llu(bit %u in group %lu)\n",
+                                  inode ? inode->i_ino : 0, blocknr, block,
+                                  e4b->bd_group);
+               }
+               mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
+               e4b->bd_info->bb_counters[order]++;
+
+               /* start of the buddy */
+               buddy = mb_find_buddy(e4b, order, &max);
+
+               do {
+                       block &= ~1UL;
+                       if (mb_test_bit(block, buddy) ||
+                                       mb_test_bit(block + 1, buddy))
+                               break;
+
+                       /* both the buddies are free, try to coalesce them */
+                       buddy2 = mb_find_buddy(e4b, order + 1, &max);
+
+                       if (!buddy2)
+                               break;
+
+                       if (order > 0) {
+                               /* for special purposes, we don't set
+                                * free bits in bitmap */
+                               mb_set_bit(block, buddy);
+                               mb_set_bit(block + 1, buddy);
+                       }
+                       e4b->bd_info->bb_counters[order]--;
+                       e4b->bd_info->bb_counters[order]--;
+
+                       block = block >> 1;
+                       order++;
+                       e4b->bd_info->bb_counters[order]++;
+
+                       mb_clear_bit(block, buddy2);
+                       buddy = buddy2;
+               } while (1);
+       }
+       mb_check_buddy(e4b);
+
+       return 0;
+}
+
+static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
+                               int needed, struct ext4_free_extent *ex)
+{
+       int next = block;
+       int max;
+       int ord;
+       void *buddy;
+
+       BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+       BUG_ON(ex == NULL);
+
+       buddy = mb_find_buddy(e4b, order, &max);
+       BUG_ON(buddy == NULL);
+       BUG_ON(block >= max);
+       if (mb_test_bit(block, buddy)) {
+               ex->fe_len = 0;
+               ex->fe_start = 0;
+               ex->fe_group = 0;
+               return 0;
+       }
+
+       /* FIXME dorp order completely ? */
+       if (likely(order == 0)) {
+               /* find actual order */
+               order = mb_find_order_for_block(e4b, block);
+               block = block >> order;
+       }
+
+       ex->fe_len = 1 << order;
+       ex->fe_start = block << order;
+       ex->fe_group = e4b->bd_group;
+
+       /* calc difference from given start */
+       next = next - ex->fe_start;
+       ex->fe_len -= next;
+       ex->fe_start += next;
+
+       while (needed > ex->fe_len &&
+              (buddy = mb_find_buddy(e4b, order, &max))) {
+
+               if (block + 1 >= max)
+                       break;
+
+               next = (block + 1) * (1 << order);
+               if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
+                       break;
+
+               ord = mb_find_order_for_block(e4b, next);
+
+               order = ord;
+               block = next >> order;
+               ex->fe_len += 1 << order;
+       }
+
+       BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
+       return ex->fe_len;
+}
+
+static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
+{
+       int ord;
+       int mlen = 0;
+       int max = 0;
+       int cur;
+       int start = ex->fe_start;
+       int len = ex->fe_len;
+       unsigned ret = 0;
+       int len0 = len;
+       void *buddy;
+
+       BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
+       BUG_ON(e4b->bd_group != ex->fe_group);
+       BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
+       mb_check_buddy(e4b);
+       mb_mark_used_double(e4b, start, len);
+
+       e4b->bd_info->bb_free -= len;
+       if (e4b->bd_info->bb_first_free == start)
+               e4b->bd_info->bb_first_free += len;
+
+       /* let's maintain fragments counter */
+       if (start != 0)
+               mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
+       if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
+               max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
+       if (mlen && max)
+               e4b->bd_info->bb_fragments++;
+       else if (!mlen && !max)
+               e4b->bd_info->bb_fragments--;
+
+       /* let's maintain buddy itself */
+       while (len) {
+               ord = mb_find_order_for_block(e4b, start);
+
+               if (((start >> ord) << ord) == start && len >= (1 << ord)) {
+                       /* the whole chunk may be allocated at once! */
+                       mlen = 1 << ord;
+                       buddy = mb_find_buddy(e4b, ord, &max);
+                       BUG_ON((start >> ord) >= max);
+                       mb_set_bit(start >> ord, buddy);
+                       e4b->bd_info->bb_counters[ord]--;
+                       start += mlen;
+                       len -= mlen;
+                       BUG_ON(len < 0);
+                       continue;
+               }
+
+               /* store for history */
+               if (ret == 0)
+                       ret = len | (ord << 16);
+
+               /* we have to split large buddy */
+               BUG_ON(ord <= 0);
+               buddy = mb_find_buddy(e4b, ord, &max);
+               mb_set_bit(start >> ord, buddy);
+               e4b->bd_info->bb_counters[ord]--;
+
+               ord--;
+               cur = (start >> ord) & ~1U;
+               buddy = mb_find_buddy(e4b, ord, &max);
+               mb_clear_bit(cur, buddy);
+               mb_clear_bit(cur + 1, buddy);
+               e4b->bd_info->bb_counters[ord]++;
+               e4b->bd_info->bb_counters[ord]++;
+       }
+
+       mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
+                       EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
+       mb_check_buddy(e4b);
+
+       return ret;
+}
+
+/*
+ * Must be called under group lock!
+ */
+static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
+                                       struct ext4_buddy *e4b)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+       int ret;
+
+       BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
+       BUG_ON(ac->ac_status == AC_STATUS_FOUND);
+
+       ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
+       ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
+       ret = mb_mark_used(e4b, &ac->ac_b_ex);
+
+       /* preallocation can change ac_b_ex, thus we store actually
+        * allocated blocks for history */
+       ac->ac_f_ex = ac->ac_b_ex;
+
+       ac->ac_status = AC_STATUS_FOUND;
+       ac->ac_tail = ret & 0xffff;
+       ac->ac_buddy = ret >> 16;
+
+       /* XXXXXXX: SUCH A HORRIBLE **CK */
+       /*FIXME!! Why ? */
+       ac->ac_bitmap_page = e4b->bd_bitmap_page;
+       get_page(ac->ac_bitmap_page);
+       ac->ac_buddy_page = e4b->bd_buddy_page;
+       get_page(ac->ac_buddy_page);
+
+       /* store last allocated for subsequent stream allocation */
+       if ((ac->ac_flags & EXT4_MB_HINT_DATA)) {
+               spin_lock(&sbi->s_md_lock);
+               sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
+               sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
+               spin_unlock(&sbi->s_md_lock);
+       }
+}
+
+/*
+ * regular allocator, for general purposes allocation
+ */
+
+static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
+                                       struct ext4_buddy *e4b,
+                                       int finish_group)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+       struct ext4_free_extent *bex = &ac->ac_b_ex;
+       struct ext4_free_extent *gex = &ac->ac_g_ex;
+       struct ext4_free_extent ex;
+       int max;
+
+       /*
+        * We don't want to scan for a whole year
+        */
+       if (ac->ac_found > sbi->s_mb_max_to_scan &&
+                       !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
+               ac->ac_status = AC_STATUS_BREAK;
+               return;
+       }
+
+       /*
+        * Haven't found good chunk so far, let's continue
+        */
+       if (bex->fe_len < gex->fe_len)
+               return;
+
+       if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
+                       && bex->fe_group == e4b->bd_group) {
+               /* recheck chunk's availability - we don't know
+                * when it was found (within this lock-unlock
+                * period or not) */
+               max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
+               if (max >= gex->fe_len) {
+                       ext4_mb_use_best_found(ac, e4b);
+                       return;
+               }
+       }
+}
+
+/*
+ * The routine checks whether found extent is good enough. If it is,
+ * then the extent gets marked used and flag is set to the context
+ * to stop scanning. Otherwise, the extent is compared with the
+ * previous found extent and if new one is better, then it's stored
+ * in the context. Later, the best found extent will be used, if
+ * mballoc can't find good enough extent.
+ *
+ * FIXME: real allocation policy is to be designed yet!
+ */
+static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
+                                       struct ext4_free_extent *ex,
+                                       struct ext4_buddy *e4b)
+{
+       struct ext4_free_extent *bex = &ac->ac_b_ex;
+       struct ext4_free_extent *gex = &ac->ac_g_ex;
+
+       BUG_ON(ex->fe_len <= 0);
+       BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
+       BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
+       BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
+
+       ac->ac_found++;
+
+       /*
+        * The special case - take what you catch first
+        */
+       if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
+               *bex = *ex;
+               ext4_mb_use_best_found(ac, e4b);
+               return;
+       }
+
+       /*
+        * Let's check whether the chuck is good enough
+        */
+       if (ex->fe_len == gex->fe_len) {
+               *bex = *ex;
+               ext4_mb_use_best_found(ac, e4b);
+               return;
+       }
+
+       /*
+        * If this is first found extent, just store it in the context
+        */
+       if (bex->fe_len == 0) {
+               *bex = *ex;
+               return;
+       }
+
+       /*
+        * If new found extent is better, store it in the context
+        */
+       if (bex->fe_len < gex->fe_len) {
+               /* if the request isn't satisfied, any found extent
+                * larger than previous best one is better */
+               if (ex->fe_len > bex->fe_len)
+                       *bex = *ex;
+       } else if (ex->fe_len > gex->fe_len) {
+               /* if the request is satisfied, then we try to find
+                * an extent that still satisfy the request, but is
+                * smaller than previous one */
+               if (ex->fe_len < bex->fe_len)
+                       *bex = *ex;
+       }
+
+       ext4_mb_check_limits(ac, e4b, 0);
+}
+
+static int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
+                                       struct ext4_buddy *e4b)
+{
+       struct ext4_free_extent ex = ac->ac_b_ex;
+       ext4_group_t group = ex.fe_group;
+       int max;
+       int err;
+
+       BUG_ON(ex.fe_len <= 0);
+       err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
+       if (err)
+               return err;
+
+       ext4_lock_group(ac->ac_sb, group);
+       max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
+
+       if (max > 0) {
+               ac->ac_b_ex = ex;
+               ext4_mb_use_best_found(ac, e4b);
+       }
+
+       ext4_unlock_group(ac->ac_sb, group);
+       ext4_mb_release_desc(e4b);
+
+       return 0;
+}
+
+static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
+                               struct ext4_buddy *e4b)
+{
+       ext4_group_t group = ac->ac_g_ex.fe_group;
+       int max;
+       int err;
+       struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+       struct ext4_super_block *es = sbi->s_es;
+       struct ext4_free_extent ex;
+
+       if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
+               return 0;
+
+       err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
+       if (err)
+               return err;
+
+       ext4_lock_group(ac->ac_sb, group);
+       max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
+                            ac->ac_g_ex.fe_len, &ex);
+
+       if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
+               ext4_fsblk_t start;
+
+               start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
+                       ex.fe_start + le32_to_cpu(es->s_first_data_block);
+               /* use do_div to get remainder (would be 64-bit modulo) */
+               if (do_div(start, sbi->s_stripe) == 0) {
+                       ac->ac_found++;
+                       ac->ac_b_ex = ex;
+                       ext4_mb_use_best_found(ac, e4b);
+               }
+       } else if (max >= ac->ac_g_ex.fe_len) {
+               BUG_ON(ex.fe_len <= 0);
+               BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
+               BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
+               ac->ac_found++;
+               ac->ac_b_ex = ex;
+               ext4_mb_use_best_found(ac, e4b);
+       } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
+               /* Sometimes, caller may want to merge even small
+                * number of blocks to an existing extent */
+               BUG_ON(ex.fe_len <= 0);
+               BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
+               BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
+               ac->ac_found++;
+               ac->ac_b_ex = ex;
+               ext4_mb_use_best_found(ac, e4b);
+       }
+       ext4_unlock_group(ac->ac_sb, group);
+       ext4_mb_release_desc(e4b);
+
+       return 0;
+}
+
+/*
+ * The routine scans buddy structures (not bitmap!) from given order
+ * to max order and tries to find big enough chunk to satisfy the req
+ */
+static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
+                                       struct ext4_buddy *e4b)
+{
+       struct super_block *sb = ac->ac_sb;
+       struct ext4_group_info *grp = e4b->bd_info;
+       void *buddy;
+       int i;
+       int k;
+       int max;
+
+       BUG_ON(ac->ac_2order <= 0);
+       for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
+               if (grp->bb_counters[i] == 0)
+                       continue;
+
+               buddy = mb_find_buddy(e4b, i, &max);
+               BUG_ON(buddy == NULL);
+
+               k = ext4_find_next_zero_bit(buddy, max, 0);
+               BUG_ON(k >= max);
+
+               ac->ac_found++;
+
+               ac->ac_b_ex.fe_len = 1 << i;
+               ac->ac_b_ex.fe_start = k << i;
+               ac->ac_b_ex.fe_group = e4b->bd_group;
+
+               ext4_mb_use_best_found(ac, e4b);
+
+               BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
+
+               if (EXT4_SB(sb)->s_mb_stats)
+                       atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
+
+               break;
+       }
+}
+
+/*
+ * The routine scans the group and measures all found extents.
+ * In order to optimize scanning, caller must pass number of
+ * free blocks in the group, so the routine can know upper limit.
+ */
+static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
+                                       struct ext4_buddy *e4b)
+{
+       struct super_block *sb = ac->ac_sb;
+       void *bitmap = EXT4_MB_BITMAP(e4b);
+       struct ext4_free_extent ex;
+       int i;
+       int free;
+
+       free = e4b->bd_info->bb_free;
+       BUG_ON(free <= 0);
+
+       i = e4b->bd_info->bb_first_free;
+
+       while (free && ac->ac_status == AC_STATUS_CONTINUE) {
+               i = ext4_find_next_zero_bit(bitmap,
+                                               EXT4_BLOCKS_PER_GROUP(sb), i);
+               if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
+                       BUG_ON(free != 0);
+                       break;
+               }
+
+               mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
+               BUG_ON(ex.fe_len <= 0);
+               BUG_ON(free < ex.fe_len);
+
+               ext4_mb_measure_extent(ac, &ex, e4b);
+
+               i += ex.fe_len;
+               free -= ex.fe_len;
+       }
+
+       ext4_mb_check_limits(ac, e4b, 1);
+}
+
+/*
+ * This is a special case for storages like raid5
+ * we try to find stripe-aligned chunks for stripe-size requests
+ * XXX should do so at least for multiples of stripe size as well
+ */
+static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
+                                struct ext4_buddy *e4b)
+{
+       struct super_block *sb = ac->ac_sb;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       void *bitmap = EXT4_MB_BITMAP(e4b);
+       struct ext4_free_extent ex;
+       ext4_fsblk_t first_group_block;
+       ext4_fsblk_t a;
+       ext4_grpblk_t i;
+       int max;
+
+       BUG_ON(sbi->s_stripe == 0);
+
+       /* find first stripe-aligned block in group */
+       first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
+               + le32_to_cpu(sbi->s_es->s_first_data_block);
+       a = first_group_block + sbi->s_stripe - 1;
+       do_div(a, sbi->s_stripe);
+       i = (a * sbi->s_stripe) - first_group_block;
+
+       while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
+               if (!mb_test_bit(i, bitmap)) {
+                       max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
+                       if (max >= sbi->s_stripe) {
+                               ac->ac_found++;
+                               ac->ac_b_ex = ex;
+                               ext4_mb_use_best_found(ac, e4b);
+                               break;
+                       }
+               }
+               i += sbi->s_stripe;
+       }
+}
+
+static int ext4_mb_good_group(struct ext4_allocation_context *ac,
+                               ext4_group_t group, int cr)
+{
+       unsigned free, fragments;
+       unsigned i, bits;
+       struct ext4_group_desc *desc;
+       struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
+
+       BUG_ON(cr < 0 || cr >= 4);
+       BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
+
+       free = grp->bb_free;
+       fragments = grp->bb_fragments;
+       if (free == 0)
+               return 0;
+       if (fragments == 0)
+               return 0;
+
+       switch (cr) {
+       case 0:
+               BUG_ON(ac->ac_2order == 0);
+               /* If this group is uninitialized, skip it initially */
+               desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
+               if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
+                       return 0;
+
+               bits = ac->ac_sb->s_blocksize_bits + 1;
+               for (i = ac->ac_2order; i <= bits; i++)
+                       if (grp->bb_counters[i] > 0)
+                               return 1;
+               break;
+       case 1:
+               if ((free / fragments) >= ac->ac_g_ex.fe_len)
+                       return 1;
+               break;
+       case 2:
+               if (free >= ac->ac_g_ex.fe_len)
+                       return 1;
+               break;
+       case 3:
+               return 1;
+       default:
+               BUG();
+       }
+
+       return 0;
+}
+
+static int ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
+{
+       ext4_group_t group;
+       ext4_group_t i;
+       int cr;
+       int err = 0;
+       int bsbits;
+       struct ext4_sb_info *sbi;
+       struct super_block *sb;
+       struct ext4_buddy e4b;
+       loff_t size, isize;
+
+       sb = ac->ac_sb;
+       sbi = EXT4_SB(sb);
+       BUG_ON(ac->ac_status == AC_STATUS_FOUND);
+
+       /* first, try the goal */
+       err = ext4_mb_find_by_goal(ac, &e4b);
+       if (err || ac->ac_status == AC_STATUS_FOUND)
+               goto out;
+
+       if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
+               goto out;
+
+       /*
+        * ac->ac2_order is set only if the fe_len is a power of 2
+        * if ac2_order is set we also set criteria to 0 so that we
+        * try exact allocation using buddy.
+        */
+       i = fls(ac->ac_g_ex.fe_len);
+       ac->ac_2order = 0;
+       /*
+        * We search using buddy data only if the order of the request
+        * is greater than equal to the sbi_s_mb_order2_reqs
+        * You can tune it via /proc/fs/ext4/<partition>/order2_req
+        */
+       if (i >= sbi->s_mb_order2_reqs) {
+               /*
+                * This should tell if fe_len is exactly power of 2
+                */
+               if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
+                       ac->ac_2order = i - 1;
+       }
+
+       bsbits = ac->ac_sb->s_blocksize_bits;
+       /* if stream allocation is enabled, use global goal */
+       size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
+       isize = i_size_read(ac->ac_inode) >> bsbits;
+       if (size < isize)
+               size = isize;
+
+       if (size < sbi->s_mb_stream_request &&
+                       (ac->ac_flags & EXT4_MB_HINT_DATA)) {
+               /* TBD: may be hot point */
+               spin_lock(&sbi->s_md_lock);
+               ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
+               ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
+               spin_unlock(&sbi->s_md_lock);
+       }
+
+       /* searching for the right group start from the goal value specified */
+       group = ac->ac_g_ex.fe_group;
+
+       /* Let's just scan groups to find more-less suitable blocks */
+       cr = ac->ac_2order ? 0 : 1;
+       /*
+        * cr == 0 try to get exact allocation,
+        * cr == 3  try to get anything
+        */
+repeat:
+       for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
+               ac->ac_criteria = cr;
+               for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
+                       struct ext4_group_info *grp;
+                       struct ext4_group_desc *desc;
+
+                       if (group == EXT4_SB(sb)->s_groups_count)
+                               group = 0;
+
+                       /* quick check to skip empty groups */
+                       grp = ext4_get_group_info(ac->ac_sb, group);
+                       if (grp->bb_free == 0)
+                               continue;
+
+                       /*
+                        * if the group is already init we check whether it is
+                        * a good group and if not we don't load the buddy
+                        */
+                       if (EXT4_MB_GRP_NEED_INIT(grp)) {
+                               /*
+                                * we need full data about the group
+                                * to make a good selection
+                                */
+                               err = ext4_mb_load_buddy(sb, group, &e4b);
+                               if (err)
+                                       goto out;
+                               ext4_mb_release_desc(&e4b);
+                       }
+
+                       /*
+                        * If the particular group doesn't satisfy our
+                        * criteria we continue with the next group
+                        */
+                       if (!ext4_mb_good_group(ac, group, cr))
+                               continue;
+
+                       err = ext4_mb_load_buddy(sb, group, &e4b);
+                       if (err)
+                               goto out;
+
+                       ext4_lock_group(sb, group);
+                       if (!ext4_mb_good_group(ac, group, cr)) {
+                               /* someone did allocation from this group */
+                               ext4_unlock_group(sb, group);
+                               ext4_mb_release_desc(&e4b);
+                               continue;
+                       }
+
+                       ac->ac_groups_scanned++;
+                       desc = ext4_get_group_desc(sb, group, NULL);
+                       if (cr == 0 || (desc->bg_flags &
+                                       cpu_to_le16(EXT4_BG_BLOCK_UNINIT) &&
+                                       ac->ac_2order != 0))
+                               ext4_mb_simple_scan_group(ac, &e4b);
+                       else if (cr == 1 &&
+                                       ac->ac_g_ex.fe_len == sbi->s_stripe)
+                               ext4_mb_scan_aligned(ac, &e4b);
+                       else
+                               ext4_mb_complex_scan_group(ac, &e4b);
+
+                       ext4_unlock_group(sb, group);
+                       ext4_mb_release_desc(&e4b);
+
+                       if (ac->ac_status != AC_STATUS_CONTINUE)
+                               break;
+               }
+       }
+
+       if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
+           !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
+               /*
+                * We've been searching too long. Let's try to allocate
+                * the best chunk we've found so far
+                */
+
+               ext4_mb_try_best_found(ac, &e4b);
+               if (ac->ac_status != AC_STATUS_FOUND) {
+                       /*
+                        * Someone more lucky has already allocated it.
+                        * The only thing we can do is just take first
+                        * found block(s)
+                       printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
+                        */
+                       ac->ac_b_ex.fe_group = 0;
+                       ac->ac_b_ex.fe_start = 0;
+                       ac->ac_b_ex.fe_len = 0;
+                       ac->ac_status = AC_STATUS_CONTINUE;
+                       ac->ac_flags |= EXT4_MB_HINT_FIRST;
+                       cr = 3;
+                       atomic_inc(&sbi->s_mb_lost_chunks);
+                       goto repeat;
+               }
+       }
+out:
+       return err;
+}
+
+#ifdef EXT4_MB_HISTORY
+struct ext4_mb_proc_session {
+       struct ext4_mb_history *history;
+       struct super_block *sb;
+       int start;
+       int max;
+};
+
+static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
+                                       struct ext4_mb_history *hs,
+                                       int first)
+{
+       if (hs == s->history + s->max)
+               hs = s->history;
+       if (!first && hs == s->history + s->start)
+               return NULL;
+       while (hs->orig.fe_len == 0) {
+               hs++;
+               if (hs == s->history + s->max)
+                       hs = s->history;
+               if (hs == s->history + s->start)
+                       return NULL;
+       }
+       return hs;
+}
+
+static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
+{
+       struct ext4_mb_proc_session *s = seq->private;
+       struct ext4_mb_history *hs;
+       int l = *pos;
+
+       if (l == 0)
+               return SEQ_START_TOKEN;
+       hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
+       if (!hs)
+               return NULL;
+       while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
+       return hs;
+}
+
+static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
+                                     loff_t *pos)
+{
+       struct ext4_mb_proc_session *s = seq->private;
+       struct ext4_mb_history *hs = v;
+
+       ++*pos;
+       if (v == SEQ_START_TOKEN)
+               return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
+       else
+               return ext4_mb_history_skip_empty(s, ++hs, 0);
+}
+
+static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
+{
+       char buf[25], buf2[25], buf3[25], *fmt;
+       struct ext4_mb_history *hs = v;
+
+       if (v == SEQ_START_TOKEN) {
+               seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
+                               "%-5s %-2s %-5s %-5s %-5s %-6s\n",
+                         "pid", "inode", "original", "goal", "result", "found",
+                          "grps", "cr", "flags", "merge", "tail", "broken");
+               return 0;
+       }
+
+       if (hs->op == EXT4_MB_HISTORY_ALLOC) {
+               fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
+                       "%-5u %-5s %-5u %-6u\n";
+               sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
+                       hs->result.fe_start, hs->result.fe_len,
+                       hs->result.fe_logical);
+               sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
+                       hs->orig.fe_start, hs->orig.fe_len,
+                       hs->orig.fe_logical);
+               sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group,
+                       hs->goal.fe_start, hs->goal.fe_len,
+                       hs->goal.fe_logical);
+               seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
+                               hs->found, hs->groups, hs->cr, hs->flags,
+                               hs->merged ? "M" : "", hs->tail,
+                               hs->buddy ? 1 << hs->buddy : 0);
+       } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
+               fmt = "%-5u %-8u %-23s %-23s %-23s\n";
+               sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
+                       hs->result.fe_start, hs->result.fe_len,
+                       hs->result.fe_logical);
+               sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
+                       hs->orig.fe_start, hs->orig.fe_len,
+                       hs->orig.fe_logical);
+               seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
+       } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
+               sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
+                       hs->result.fe_start, hs->result.fe_len);
+               seq_printf(seq, "%-5u %-8u %-23s discard\n",
+                               hs->pid, hs->ino, buf2);
+       } else if (hs->op == EXT4_MB_HISTORY_FREE) {
+               sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
+                       hs->result.fe_start, hs->result.fe_len);
+               seq_printf(seq, "%-5u %-8u %-23s free\n",
+                               hs->pid, hs->ino, buf2);
+       }
+       return 0;
+}
+
+static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations ext4_mb_seq_history_ops = {
+       .start  = ext4_mb_seq_history_start,
+       .next   = ext4_mb_seq_history_next,
+       .stop   = ext4_mb_seq_history_stop,
+       .show   = ext4_mb_seq_history_show,
+};
+
+static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
+{
+       struct super_block *sb = PDE(inode)->data;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       struct ext4_mb_proc_session *s;
+       int rc;
+       int size;
+
+       s = kmalloc(sizeof(*s), GFP_KERNEL);
+       if (s == NULL)
+               return -ENOMEM;
+       s->sb = sb;
+       size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
+       s->history = kmalloc(size, GFP_KERNEL);
+       if (s->history == NULL) {
+               kfree(s);
+               return -ENOMEM;
+       }
+
+       spin_lock(&sbi->s_mb_history_lock);
+       memcpy(s->history, sbi->s_mb_history, size);
+       s->max = sbi->s_mb_history_max;
+       s->start = sbi->s_mb_history_cur % s->max;
+       spin_unlock(&sbi->s_mb_history_lock);
+
+       rc = seq_open(file, &ext4_mb_seq_history_ops);
+       if (rc == 0) {
+               struct seq_file *m = (struct seq_file *)file->private_data;
+               m->private = s;
+       } else {
+               kfree(s->history);
+               kfree(s);
+       }
+       return rc;
+
+}
+
+static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *seq = (struct seq_file *)file->private_data;
+       struct ext4_mb_proc_session *s = seq->private;
+       kfree(s->history);
+       kfree(s);
+       return seq_release(inode, file);
+}
+
+static ssize_t ext4_mb_seq_history_write(struct file *file,
+                               const char __user *buffer,
+                               size_t count, loff_t *ppos)
+{
+       struct seq_file *seq = (struct seq_file *)file->private_data;
+       struct ext4_mb_proc_session *s = seq->private;
+       struct super_block *sb = s->sb;
+       char str[32];
+       int value;
+
+       if (count >= sizeof(str)) {
+               printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
+                               "mb_history", (int)sizeof(str));
+               return -EOVERFLOW;
+       }
+
+       if (copy_from_user(str, buffer, count))
+               return -EFAULT;
+
+       value = simple_strtol(str, NULL, 0);
+       if (value < 0)
+               return -ERANGE;
+       EXT4_SB(sb)->s_mb_history_filter = value;
+
+       return count;
+}
+
+static struct file_operations ext4_mb_seq_history_fops = {
+       .owner          = THIS_MODULE,
+       .open           = ext4_mb_seq_history_open,
+       .read           = seq_read,
+       .write          = ext4_mb_seq_history_write,
+       .llseek         = seq_lseek,
+       .release        = ext4_mb_seq_history_release,
+};
+
+static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
+{
+       struct super_block *sb = seq->private;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       ext4_group_t group;
+
+       if (*pos < 0 || *pos >= sbi->s_groups_count)
+               return NULL;
+
+       group = *pos + 1;
+       return (void *) group;
+}
+
+static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+       struct super_block *sb = seq->private;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       ext4_group_t group;
+
+       ++*pos;
+       if (*pos < 0 || *pos >= sbi->s_groups_count)
+               return NULL;
+       group = *pos + 1;
+       return (void *) group;;
+}
+
+static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
+{
+       struct super_block *sb = seq->private;
+       long group = (long) v;
+       int i;
+       int err;
+       struct ext4_buddy e4b;
+       struct sg {
+               struct ext4_group_info info;
+               unsigned short counters[16];
+       } sg;
+
+       group--;
+       if (group == 0)
+               seq_printf(seq, "#%-5s: %-5s %-5s %-5s "
+                               "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
+                                 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
+                          "group", "free", "frags", "first",
+                          "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
+                          "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
+
+       i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
+               sizeof(struct ext4_group_info);
+       err = ext4_mb_load_buddy(sb, group, &e4b);
+       if (err) {
+               seq_printf(seq, "#%-5lu: I/O error\n", group);
+               return 0;
+       }
+       ext4_lock_group(sb, group);
+       memcpy(&sg, ext4_get_group_info(sb, group), i);
+       ext4_unlock_group(sb, group);
+       ext4_mb_release_desc(&e4b);
+
+       seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free,
+                       sg.info.bb_fragments, sg.info.bb_first_free);
+       for (i = 0; i <= 13; i++)
+               seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
+                               sg.info.bb_counters[i] : 0);
+       seq_printf(seq, " ]\n");
+
+       return 0;
+}
+
+static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
+{
+}
+
+static struct seq_operations ext4_mb_seq_groups_ops = {
+       .start  = ext4_mb_seq_groups_start,
+       .next   = ext4_mb_seq_groups_next,
+       .stop   = ext4_mb_seq_groups_stop,
+       .show   = ext4_mb_seq_groups_show,
+};
+
+static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
+{
+       struct super_block *sb = PDE(inode)->data;
+       int rc;
+
+       rc = seq_open(file, &ext4_mb_seq_groups_ops);
+       if (rc == 0) {
+               struct seq_file *m = (struct seq_file *)file->private_data;
+               m->private = sb;
+       }
+       return rc;
+
+}
+
+static struct file_operations ext4_mb_seq_groups_fops = {
+       .owner          = THIS_MODULE,
+       .open           = ext4_mb_seq_groups_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
+static void ext4_mb_history_release(struct super_block *sb)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+       remove_proc_entry("mb_groups", sbi->s_mb_proc);
+       remove_proc_entry("mb_history", sbi->s_mb_proc);
+
+       kfree(sbi->s_mb_history);
+}
+
+static void ext4_mb_history_init(struct super_block *sb)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       int i;
+
+       if (sbi->s_mb_proc != NULL) {
+               struct proc_dir_entry *p;
+               p = create_proc_entry("mb_history", S_IRUGO, sbi->s_mb_proc);
+               if (p) {
+                       p->proc_fops = &ext4_mb_seq_history_fops;
+                       p->data = sb;
+               }
+               p = create_proc_entry("mb_groups", S_IRUGO, sbi->s_mb_proc);
+               if (p) {
+                       p->proc_fops = &ext4_mb_seq_groups_fops;
+                       p->data = sb;
+               }
+       }
+
+       sbi->s_mb_history_max = 1000;
+       sbi->s_mb_history_cur = 0;
+       spin_lock_init(&sbi->s_mb_history_lock);
+       i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
+       sbi->s_mb_history = kmalloc(i, GFP_KERNEL);
+       if (likely(sbi->s_mb_history != NULL))
+               memset(sbi->s_mb_history, 0, i);
+       /* if we can't allocate history, then we simple won't use it */
+}
+
+static void ext4_mb_store_history(struct ext4_allocation_context *ac)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+       struct ext4_mb_history h;
+
+       if (unlikely(sbi->s_mb_history == NULL))
+               return;
+
+       if (!(ac->ac_op & sbi->s_mb_history_filter))
+               return;
+
+       h.op = ac->ac_op;
+       h.pid = current->pid;
+       h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
+       h.orig = ac->ac_o_ex;
+       h.result = ac->ac_b_ex;
+       h.flags = ac->ac_flags;
+       h.found = ac->ac_found;
+       h.groups = ac->ac_groups_scanned;
+       h.cr = ac->ac_criteria;
+       h.tail = ac->ac_tail;
+       h.buddy = ac->ac_buddy;
+       h.merged = 0;
+       if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
+               if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
+                               ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
+                       h.merged = 1;
+               h.goal = ac->ac_g_ex;
+               h.result = ac->ac_f_ex;
+       }
+
+       spin_lock(&sbi->s_mb_history_lock);
+       memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
+       if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
+               sbi->s_mb_history_cur = 0;
+       spin_unlock(&sbi->s_mb_history_lock);
+}
+
+#else
+#define ext4_mb_history_release(sb)
+#define ext4_mb_history_init(sb)
+#endif
+
+static int ext4_mb_init_backend(struct super_block *sb)
+{
+       ext4_group_t i;
+       int j, len, metalen;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       int num_meta_group_infos =
+               (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >>
+                       EXT4_DESC_PER_BLOCK_BITS(sb);
+       struct ext4_group_info **meta_group_info;
+
+       /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
+        * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
+        * So a two level scheme suffices for now. */
+       sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) *
+                                   num_meta_group_infos, GFP_KERNEL);
+       if (sbi->s_group_info == NULL) {
+               printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
+               return -ENOMEM;
+       }
+       sbi->s_buddy_cache = new_inode(sb);
+       if (sbi->s_buddy_cache == NULL) {
+               printk(KERN_ERR "EXT4-fs: can't get new inode\n");
+               goto err_freesgi;
+       }
+       EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
+
+       metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb);
+       for (i = 0; i < num_meta_group_infos; i++) {
+               if ((i + 1) == num_meta_group_infos)
+                       metalen = sizeof(*meta_group_info) *
+                               (sbi->s_groups_count -
+                                       (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
+               meta_group_info = kmalloc(metalen, GFP_KERNEL);
+               if (meta_group_info == NULL) {
+                       printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
+                              "buddy group\n");
+                       goto err_freemeta;
+               }
+               sbi->s_group_info[i] = meta_group_info;
+       }
+
+       /*
+        * calculate needed size. if change bb_counters size,
+        * don't forget about ext4_mb_generate_buddy()
+        */
+       len = sizeof(struct ext4_group_info);
+       len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
+       for (i = 0; i < sbi->s_groups_count; i++) {
+               struct ext4_group_desc *desc;
+
+               meta_group_info =
+                       sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)];
+               j = i & (EXT4_DESC_PER_BLOCK(sb) - 1);
+
+               meta_group_info[j] = kzalloc(len, GFP_KERNEL);
+               if (meta_group_info[j] == NULL) {
+                       printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
+                       i--;
+                       goto err_freebuddy;
+               }
+               desc = ext4_get_group_desc(sb, i, NULL);
+               if (desc == NULL) {
+                       printk(KERN_ERR
+                               "EXT4-fs: can't read descriptor %lu\n", i);
+                       goto err_freebuddy;
+               }
+               memset(meta_group_info[j], 0, len);
+               set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
+                       &(meta_group_info[j]->bb_state));
+
+               /*
+                * initialize bb_free to be able to skip
+                * empty groups without initialization
+                */
+               if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+                       meta_group_info[j]->bb_free =
+                               ext4_free_blocks_after_init(sb, i, desc);
+               } else {
+                       meta_group_info[j]->bb_free =
+                               le16_to_cpu(desc->bg_free_blocks_count);
+               }
+
+               INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list);
+
+#ifdef DOUBLE_CHECK
+               {
+                       struct buffer_head *bh;
+                       meta_group_info[j]->bb_bitmap =
+                               kmalloc(sb->s_blocksize, GFP_KERNEL);
+                       BUG_ON(meta_group_info[j]->bb_bitmap == NULL);
+                       bh = read_block_bitmap(sb, i);
+                       BUG_ON(bh == NULL);
+                       memcpy(meta_group_info[j]->bb_bitmap, bh->b_data,
+                                       sb->s_blocksize);
+                       put_bh(bh);
+               }
+#endif
+
+       }
+
+       return 0;
+
+err_freebuddy:
+       while (i >= 0) {
+               kfree(ext4_get_group_info(sb, i));
+               i--;
+       }
+       i = num_meta_group_infos;
+err_freemeta:
+       while (--i >= 0)
+               kfree(sbi->s_group_info[i]);
+       iput(sbi->s_buddy_cache);
+err_freesgi:
+       kfree(sbi->s_group_info);
+       return -ENOMEM;
+}
+
+int ext4_mb_init(struct super_block *sb, int needs_recovery)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       unsigned i;
+       unsigned offset;
+       unsigned max;
+
+       if (!test_opt(sb, MBALLOC))
+               return 0;
+
+       i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
+
+       sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
+       if (sbi->s_mb_offsets == NULL) {
+               clear_opt(sbi->s_mount_opt, MBALLOC);
+               return -ENOMEM;
+       }
+       sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
+       if (sbi->s_mb_maxs == NULL) {
+               clear_opt(sbi->s_mount_opt, MBALLOC);
+               kfree(sbi->s_mb_maxs);
+               return -ENOMEM;
+       }
+
+       /* order 0 is regular bitmap */
+       sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
+       sbi->s_mb_offsets[0] = 0;
+
+       i = 1;
+       offset = 0;
+       max = sb->s_blocksize << 2;
+       do {
+               sbi->s_mb_offsets[i] = offset;
+               sbi->s_mb_maxs[i] = max;
+               offset += 1 << (sb->s_blocksize_bits - i);
+               max = max >> 1;
+               i++;
+       } while (i <= sb->s_blocksize_bits + 1);
+
+       /* init file for buddy data */
+       i = ext4_mb_init_backend(sb);
+       if (i) {
+               clear_opt(sbi->s_mount_opt, MBALLOC);
+               kfree(sbi->s_mb_offsets);
+               kfree(sbi->s_mb_maxs);
+               return i;
+       }
+
+       spin_lock_init(&sbi->s_md_lock);
+       INIT_LIST_HEAD(&sbi->s_active_transaction);
+       INIT_LIST_HEAD(&sbi->s_closed_transaction);
+       INIT_LIST_HEAD(&sbi->s_committed_transaction);
+       spin_lock_init(&sbi->s_bal_lock);
+
+       sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
+       sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
+       sbi->s_mb_stats = MB_DEFAULT_STATS;
+       sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
+       sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
+       sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
+       sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
+
+       i = sizeof(struct ext4_locality_group) * NR_CPUS;
+       sbi->s_locality_groups = kmalloc(i, GFP_KERNEL);
+       if (sbi->s_locality_groups == NULL) {
+               clear_opt(sbi->s_mount_opt, MBALLOC);
+               kfree(sbi->s_mb_offsets);
+               kfree(sbi->s_mb_maxs);
+               return -ENOMEM;
+       }
+       for (i = 0; i < NR_CPUS; i++) {
+               struct ext4_locality_group *lg;
+               lg = &sbi->s_locality_groups[i];
+               mutex_init(&lg->lg_mutex);
+               INIT_LIST_HEAD(&lg->lg_prealloc_list);
+               spin_lock_init(&lg->lg_prealloc_lock);
+       }
+
+       ext4_mb_init_per_dev_proc(sb);
+       ext4_mb_history_init(sb);
+
+       printk("EXT4-fs: mballoc enabled\n");
+       return 0;
+}
+
+/* need to called with ext4 group lock (ext4_lock_group) */
+static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
+{
+       struct ext4_prealloc_space *pa;
+       struct list_head *cur, *tmp;
+       int count = 0;
+
+       list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
+               pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
+               list_del(&pa->pa_group_list);
+               count++;
+               kfree(pa);
+       }
+       if (count)
+               mb_debug("mballoc: %u PAs left\n", count);
+
+}
+
+int ext4_mb_release(struct super_block *sb)
+{
+       ext4_group_t i;
+       int num_meta_group_infos;
+       struct ext4_group_info *grinfo;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+       if (!test_opt(sb, MBALLOC))
+               return 0;
+
+       /* release freed, non-committed blocks */
+       spin_lock(&sbi->s_md_lock);
+       list_splice_init(&sbi->s_closed_transaction,
+                       &sbi->s_committed_transaction);
+       list_splice_init(&sbi->s_active_transaction,
+                       &sbi->s_committed_transaction);
+       spin_unlock(&sbi->s_md_lock);
+       ext4_mb_free_committed_blocks(sb);
+
+       if (sbi->s_group_info) {
+               for (i = 0; i < sbi->s_groups_count; i++) {
+                       grinfo = ext4_get_group_info(sb, i);
+#ifdef DOUBLE_CHECK
+                       kfree(grinfo->bb_bitmap);
+#endif
+                       ext4_lock_group(sb, i);
+                       ext4_mb_cleanup_pa(grinfo);
+                       ext4_unlock_group(sb, i);
+                       kfree(grinfo);
+               }
+               num_meta_group_infos = (sbi->s_groups_count +
+                               EXT4_DESC_PER_BLOCK(sb) - 1) >>
+                       EXT4_DESC_PER_BLOCK_BITS(sb);
+               for (i = 0; i < num_meta_group_infos; i++)
+                       kfree(sbi->s_group_info[i]);
+               kfree(sbi->s_group_info);
+       }
+       kfree(sbi->s_mb_offsets);
+       kfree(sbi->s_mb_maxs);
+       if (sbi->s_buddy_cache)
+               iput(sbi->s_buddy_cache);
+       if (sbi->s_mb_stats) {
+               printk(KERN_INFO
+                      "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
+                               atomic_read(&sbi->s_bal_allocated),
+                               atomic_read(&sbi->s_bal_reqs),
+                               atomic_read(&sbi->s_bal_success));
+               printk(KERN_INFO
+                     "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
+                               "%u 2^N hits, %u breaks, %u lost\n",
+                               atomic_read(&sbi->s_bal_ex_scanned),
+                               atomic_read(&sbi->s_bal_goals),
+                               atomic_read(&sbi->s_bal_2orders),
+                               atomic_read(&sbi->s_bal_breaks),
+                               atomic_read(&sbi->s_mb_lost_chunks));
+               printk(KERN_INFO
+                      "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
+                               sbi->s_mb_buddies_generated++,
+                               sbi->s_mb_generation_time);
+               printk(KERN_INFO
+                      "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
+                               atomic_read(&sbi->s_mb_preallocated),
+                               atomic_read(&sbi->s_mb_discarded));
+       }
+
+       kfree(sbi->s_locality_groups);
+
+       ext4_mb_history_release(sb);
+       ext4_mb_destroy_per_dev_proc(sb);
+
+       return 0;
+}
+
+static void ext4_mb_free_committed_blocks(struct super_block *sb)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       int err;
+       int i;
+       int count = 0;
+       int count2 = 0;
+       struct ext4_free_metadata *md;
+       struct ext4_buddy e4b;
+
+       if (list_empty(&sbi->s_committed_transaction))
+               return;
+
+       /* there is committed blocks to be freed yet */
+       do {
+               /* get next array of blocks */
+               md = NULL;
+               spin_lock(&sbi->s_md_lock);
+               if (!list_empty(&sbi->s_committed_transaction)) {
+                       md = list_entry(sbi->s_committed_transaction.next,
+                                       struct ext4_free_metadata, list);
+                       list_del(&md->list);
+               }
+               spin_unlock(&sbi->s_md_lock);
+
+               if (md == NULL)
+                       break;
+
+               mb_debug("gonna free %u blocks in group %lu (0x%p):",
+                               md->num, md->group, md);
+
+               err = ext4_mb_load_buddy(sb, md->group, &e4b);
+               /* we expect to find existing buddy because it's pinned */
+               BUG_ON(err != 0);
+
+               /* there are blocks to put in buddy to make them really free */
+               count += md->num;
+               count2++;
+               ext4_lock_group(sb, md->group);
+               for (i = 0; i < md->num; i++) {
+                       mb_debug(" %u", md->blocks[i]);
+                       err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
+                       BUG_ON(err != 0);
+               }
+               mb_debug("\n");
+               ext4_unlock_group(sb, md->group);
+
+               /* balance refcounts from ext4_mb_free_metadata() */
+               page_cache_release(e4b.bd_buddy_page);
+               page_cache_release(e4b.bd_bitmap_page);
+
+               kfree(md);
+               ext4_mb_release_desc(&e4b);
+
+       } while (md);
+
+       mb_debug("freed %u blocks in %u structures\n", count, count2);
+}
+
+#define EXT4_ROOT                      "ext4"
+#define EXT4_MB_STATS_NAME             "stats"
+#define EXT4_MB_MAX_TO_SCAN_NAME       "max_to_scan"
+#define EXT4_MB_MIN_TO_SCAN_NAME       "min_to_scan"
+#define EXT4_MB_ORDER2_REQ             "order2_req"
+#define EXT4_MB_STREAM_REQ             "stream_req"
+#define EXT4_MB_GROUP_PREALLOC         "group_prealloc"
+
+
+
+#define MB_PROC_VALUE_READ(name)                               \
+static int ext4_mb_read_##name(char *page, char **start,       \
+               off_t off, int count, int *eof, void *data)     \
+{                                                              \
+       struct ext4_sb_info *sbi = data;                        \
+       int len;                                                \
+       *eof = 1;                                               \
+       if (off != 0)                                           \
+               return 0;                                       \
+       len = sprintf(page, "%ld\n", sbi->s_mb_##name);         \
+       *start = page;                                          \
+       return len;                                             \
+}
+
+#define MB_PROC_VALUE_WRITE(name)                              \
+static int ext4_mb_write_##name(struct file *file,             \
+               const char __user *buf, unsigned long cnt, void *data)  \
+{                                                              \
+       struct ext4_sb_info *sbi = data;                        \
+       char str[32];                                           \
+       long value;                                             \
+       if (cnt >= sizeof(str))                                 \
+               return -EINVAL;                                 \
+       if (copy_from_user(str, buf, cnt))                      \
+               return -EFAULT;                                 \
+       value = simple_strtol(str, NULL, 0);                    \
+       if (value <= 0)                                         \
+               return -ERANGE;                                 \
+       sbi->s_mb_##name = value;                               \
+       return cnt;                                             \
+}
+
+MB_PROC_VALUE_READ(stats);
+MB_PROC_VALUE_WRITE(stats);
+MB_PROC_VALUE_READ(max_to_scan);
+MB_PROC_VALUE_WRITE(max_to_scan);
+MB_PROC_VALUE_READ(min_to_scan);
+MB_PROC_VALUE_WRITE(min_to_scan);
+MB_PROC_VALUE_READ(order2_reqs);
+MB_PROC_VALUE_WRITE(order2_reqs);
+MB_PROC_VALUE_READ(stream_request);
+MB_PROC_VALUE_WRITE(stream_request);
+MB_PROC_VALUE_READ(group_prealloc);
+MB_PROC_VALUE_WRITE(group_prealloc);
+
+#define        MB_PROC_HANDLER(name, var)                                      \
+do {                                                                   \
+       proc = create_proc_entry(name, mode, sbi->s_mb_proc);           \
+       if (proc == NULL) {                                             \
+               printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
+               goto err_out;                                           \
+       }                                                               \
+       proc->data = sbi;                                               \
+       proc->read_proc  = ext4_mb_read_##var ;                         \
+       proc->write_proc = ext4_mb_write_##var;                         \
+} while (0)
+
+static int ext4_mb_init_per_dev_proc(struct super_block *sb)
+{
+       mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       struct proc_dir_entry *proc;
+       char devname[64];
+
+       snprintf(devname, sizeof(devname) - 1, "%s",
+               bdevname(sb->s_bdev, devname));
+       sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);
+
+       MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);
+       MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan);
+       MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan);
+       MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs);
+       MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request);
+       MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc);
+
+       return 0;
+
+err_out:
+       printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);
+       remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
+       remove_proc_entry(devname, proc_root_ext4);
+       sbi->s_mb_proc = NULL;
+
+       return -ENOMEM;
+}
+
+static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       char devname[64];
+
+       if (sbi->s_mb_proc == NULL)
+               return -EINVAL;
+
+       snprintf(devname, sizeof(devname) - 1, "%s",
+               bdevname(sb->s_bdev, devname));
+       remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
+       remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
+       remove_proc_entry(devname, proc_root_ext4);
+
+       return 0;
+}
+
+int __init init_ext4_mballoc(void)
+{
+       ext4_pspace_cachep =
+               kmem_cache_create("ext4_prealloc_space",
+                                    sizeof(struct ext4_prealloc_space),
+                                    0, SLAB_RECLAIM_ACCOUNT, NULL);
+       if (ext4_pspace_cachep == NULL)
+               return -ENOMEM;
+
+#ifdef CONFIG_PROC_FS
+       proc_root_ext4 = proc_mkdir(EXT4_ROOT, proc_root_fs);
+       if (proc_root_ext4 == NULL)
+               printk(KERN_ERR "EXT4-fs: Unable to create %s\n", EXT4_ROOT);
+#endif
+
+       return 0;
+}
+
+void exit_ext4_mballoc(void)
+{
+       /* XXX: synchronize_rcu(); */
+       kmem_cache_destroy(ext4_pspace_cachep);
+#ifdef CONFIG_PROC_FS
+       remove_proc_entry(EXT4_ROOT, proc_root_fs);
+#endif
+}
+
+
+/*
+ * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
+ * Returns 0 if success or error code
+ */
+static int ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
+                               handle_t *handle)
+{
+       struct buffer_head *bitmap_bh = NULL;
+       struct ext4_super_block *es;
+       struct ext4_group_desc *gdp;
+       struct buffer_head *gdp_bh;
+       struct ext4_sb_info *sbi;
+       struct super_block *sb;
+       ext4_fsblk_t block;
+       int err;
+
+       BUG_ON(ac->ac_status != AC_STATUS_FOUND);
+       BUG_ON(ac->ac_b_ex.fe_len <= 0);
+
+       sb = ac->ac_sb;
+       sbi = EXT4_SB(sb);
+       es = sbi->s_es;
+
+       ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group,
+                       gdp->bg_free_blocks_count);
+
+       err = -EIO;
+       bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group);
+       if (!bitmap_bh)
+               goto out_err;
+
+       err = ext4_journal_get_write_access(handle, bitmap_bh);
+       if (err)
+               goto out_err;
+
+       err = -EIO;
+       gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
+       if (!gdp)
+               goto out_err;
+
+       err = ext4_journal_get_write_access(handle, gdp_bh);
+       if (err)
+               goto out_err;
+
+       block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
+               + ac->ac_b_ex.fe_start
+               + le32_to_cpu(es->s_first_data_block);
+
+       if (block == ext4_block_bitmap(sb, gdp) ||
+                       block == ext4_inode_bitmap(sb, gdp) ||
+                       in_range(block, ext4_inode_table(sb, gdp),
+                               EXT4_SB(sb)->s_itb_per_group)) {
+
+               ext4_error(sb, __FUNCTION__,
+                          "Allocating block in system zone - block = %llu",
+                          block);
+       }
+#ifdef AGGRESSIVE_CHECK
+       {
+               int i;
+               for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
+                       BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
+                                               bitmap_bh->b_data));
+               }
+       }
+#endif
+       mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
+                               ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
+
+       spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
+       if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
+               gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
+               gdp->bg_free_blocks_count =
+                       cpu_to_le16(ext4_free_blocks_after_init(sb,
+                                               ac->ac_b_ex.fe_group,
+                                               gdp));
+       }
+       gdp->bg_free_blocks_count =
+               cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)
+                               - ac->ac_b_ex.fe_len);
+       gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
+       spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
+       percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
+
+       err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+       if (err)
+               goto out_err;
+       err = ext4_journal_dirty_metadata(handle, gdp_bh);
+
+out_err:
+       sb->s_dirt = 1;
+       put_bh(bitmap_bh);
+       return err;
+}
+
+/*
+ * here we normalize request for locality group
+ * Group request are normalized to s_strip size if we set the same via mount
+ * option. If not we set it to s_mb_group_prealloc which can be configured via
+ * /proc/fs/ext4/<partition>/group_prealloc
+ *
+ * XXX: should we try to preallocate more than the group has now?
+ */
+static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
+{
+       struct super_block *sb = ac->ac_sb;
+       struct ext4_locality_group *lg = ac->ac_lg;
+
+       BUG_ON(lg == NULL);
+       if (EXT4_SB(sb)->s_stripe)
+               ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
+       else
+               ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
+       mb_debug("#%u: goal %lu blocks for locality group\n",
+               current->pid, ac->ac_g_ex.fe_len);
+}
+
+/*
+ * Normalization means making request better in terms of
+ * size and alignment
+ */
+static void ext4_mb_normalize_request(struct ext4_allocation_context *ac,
+                               struct ext4_allocation_request *ar)
+{
+       int bsbits, max;
+       ext4_lblk_t end;
+       struct list_head *cur;
+       loff_t size, orig_size, start_off;
+       ext4_lblk_t start, orig_start;
+       struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
+
+       /* do normalize only data requests, metadata requests
+          do not need preallocation */
+       if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
+               return;
+
+       /* sometime caller may want exact blocks */
+       if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
+               return;
+
+       /* caller may indicate that preallocation isn't
+        * required (it's a tail, for example) */
+       if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
+               return;
+
+       if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
+               ext4_mb_normalize_group_request(ac);
+               return ;
+       }
+
+       bsbits = ac->ac_sb->s_blocksize_bits;
+
+       /* first, let's learn actual file size
+        * given current request is allocated */
+       size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
+       size = size << bsbits;
+       if (size < i_size_read(ac->ac_inode))
+               size = i_size_read(ac->ac_inode);
+
+       /* max available blocks in a free group */
+       max = EXT4_BLOCKS_PER_GROUP(ac->ac_sb) - 1 - 1 -
+                               EXT4_SB(ac->ac_sb)->s_itb_per_group;
+
+#define NRL_CHECK_SIZE(req, size, max,bits)    \
+               (req <= (size) || max <= ((size) >> bits))
+
+       /* first, try to predict filesize */
+       /* XXX: should this table be tunable? */
+       start_off = 0;
+       if (size <= 16 * 1024) {
+               size = 16 * 1024;
+       } else if (size <= 32 * 1024) {
+               size = 32 * 1024;
+       } else if (size <= 64 * 1024) {
+               size = 64 * 1024;
+       } else if (size <= 128 * 1024) {
+               size = 128 * 1024;
+       } else if (size <= 256 * 1024) {
+               size = 256 * 1024;
+       } else if (size <= 512 * 1024) {
+               size = 512 * 1024;
+       } else if (size <= 1024 * 1024) {
+               size = 1024 * 1024;
+       } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, bsbits)) {
+               start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
+                                               (20 - bsbits)) << 20;
+               size = 1024 * 1024;
+       } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, bsbits)) {
+               start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
+                                                       (22 - bsbits)) << 22;
+               size = 4 * 1024 * 1024;
+       } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
+                                       (8<<20)>>bsbits, max, bsbits)) {
+               start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
+                                                       (23 - bsbits)) << 23;
+               size = 8 * 1024 * 1024;
+       } else {
+               start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
+               size      = ac->ac_o_ex.fe_len << bsbits;
+       }
+       orig_size = size = size >> bsbits;
+       orig_start = start = start_off >> bsbits;
+
+       /* don't cover already allocated blocks in selected range */
+       if (ar->pleft && start <= ar->lleft) {
+               size -= ar->lleft + 1 - start;
+               start = ar->lleft + 1;
+       }
+       if (ar->pright && start + size - 1 >= ar->lright)
+               size -= start + size - ar->lright;
+
+       end = start + size;
+
+       /* check we don't cross already preallocated blocks */
+       rcu_read_lock();
+       list_for_each_rcu(cur, &ei->i_prealloc_list) {
+               struct ext4_prealloc_space *pa;
+               unsigned long pa_end;
+
+               pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+
+               if (pa->pa_deleted)
+                       continue;
+               spin_lock(&pa->pa_lock);
+               if (pa->pa_deleted) {
+                       spin_unlock(&pa->pa_lock);
+                       continue;
+               }
+
+               pa_end = pa->pa_lstart + pa->pa_len;
+
+               /* PA must not overlap original request */
+               BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
+                       ac->ac_o_ex.fe_logical < pa->pa_lstart));
+
+               /* skip PA normalized request doesn't overlap with */
+               if (pa->pa_lstart >= end) {
+                       spin_unlock(&pa->pa_lock);
+                       continue;
+               }
+               if (pa_end <= start) {
+                       spin_unlock(&pa->pa_lock);
+                       continue;
+               }
+               BUG_ON(pa->pa_lstart <= start && pa_end >= end);
+
+               if (pa_end <= ac->ac_o_ex.fe_logical) {
+                       BUG_ON(pa_end < start);
+                       start = pa_end;
+               }
+
+               if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
+                       BUG_ON(pa->pa_lstart > end);
+                       end = pa->pa_lstart;
+               }
+               spin_unlock(&pa->pa_lock);
+       }
+       rcu_read_unlock();
+       size = end - start;
+
+       /* XXX: extra loop to check we really don't overlap preallocations */
+       rcu_read_lock();
+       list_for_each_rcu(cur, &ei->i_prealloc_list) {
+               struct ext4_prealloc_space *pa;
+               unsigned long pa_end;
+               pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+               spin_lock(&pa->pa_lock);
+               if (pa->pa_deleted == 0) {
+                       pa_end = pa->pa_lstart + pa->pa_len;
+                       BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
+               }
+               spin_unlock(&pa->pa_lock);
+       }
+       rcu_read_unlock();
+
+       if (start + size <= ac->ac_o_ex.fe_logical &&
+                       start > ac->ac_o_ex.fe_logical) {
+               printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
+                       (unsigned long) start, (unsigned long) size,
+                       (unsigned long) ac->ac_o_ex.fe_logical);
+       }
+       BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
+                       start > ac->ac_o_ex.fe_logical);
+       BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
+
+       /* now prepare goal request */
+
+       /* XXX: is it better to align blocks WRT to logical
+        * placement or satisfy big request as is */
+       ac->ac_g_ex.fe_logical = start;
+       ac->ac_g_ex.fe_len = size;
+
+       /* define goal start in order to merge */
+       if (ar->pright && (ar->lright == (start + size))) {
+               /* merge to the right */
+               ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
+                                               &ac->ac_f_ex.fe_group,
+                                               &ac->ac_f_ex.fe_start);
+               ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
+       }
+       if (ar->pleft && (ar->lleft + 1 == start)) {
+               /* merge to the left */
+               ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
+                                               &ac->ac_f_ex.fe_group,
+                                               &ac->ac_f_ex.fe_start);
+               ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
+       }
+
+       mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size,
+               (unsigned) orig_size, (unsigned) start);
+}
+
+static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
+{
+       struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+
+       if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
+               atomic_inc(&sbi->s_bal_reqs);
+               atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
+               if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
+                       atomic_inc(&sbi->s_bal_success);
+               atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
+               if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
+                               ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
+                       atomic_inc(&sbi->s_bal_goals);
+               if (ac->ac_found > sbi->s_mb_max_to_scan)
+                       atomic_inc(&sbi->s_bal_breaks);
+       }
+
+       ext4_mb_store_history(ac);
+}
+
+/*
+ * use blocks preallocated to inode
+ */
+static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
+                               struct ext4_prealloc_space *pa)
+{
+       ext4_fsblk_t start;
+       ext4_fsblk_t end;
+       int len;
+
+       /* found preallocated blocks, use them */
+       start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
+       end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
+       len = end - start;
+       ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
+                                       &ac->ac_b_ex.fe_start);
+       ac->ac_b_ex.fe_len = len;
+       ac->ac_status = AC_STATUS_FOUND;
+       ac->ac_pa = pa;
+
+       BUG_ON(start < pa->pa_pstart);
+       BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
+       BUG_ON(pa->pa_free < len);
+       pa->pa_free -= len;
+
+       mb_debug("use %llu/%lu from inode pa %p\n", start, len, pa);
+}
+
+/*
+ * use blocks preallocated to locality group
+ */
+static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
+                               struct ext4_prealloc_space *pa)
+{
+       unsigned len = ac->ac_o_ex.fe_len;
+
+       ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
+                                       &ac->ac_b_ex.fe_group,
+                                       &ac->ac_b_ex.fe_start);
+       ac->ac_b_ex.fe_len = len;
+       ac->ac_status = AC_STATUS_FOUND;
+       ac->ac_pa = pa;
+
+       /* we don't correct pa_pstart or pa_plen here to avoid
+        * possible race when tte group is being loaded concurrently
+        * instead we correct pa later, after blocks are marked
+        * in on-disk bitmap -- see ext4_mb_release_context() */
+       /*
+        * FIXME!! but the other CPUs can look at this particular
+        * pa and think that it have enought free blocks if we
+        * don't update pa_free here right ?
+        */
+       mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
+}
+
+/*
+ * search goal blocks in preallocated space
+ */
+static int ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
+{
+       struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
+       struct ext4_locality_group *lg;
+       struct ext4_prealloc_space *pa;
+       struct list_head *cur;
+
+       /* only data can be preallocated */
+       if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
+               return 0;
+
+       /* first, try per-file preallocation */
+       rcu_read_lock();
+       list_for_each_rcu(cur, &ei->i_prealloc_list) {
+               pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+
+               /* all fields in this condition don't change,
+                * so we can skip locking for them */
+               if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
+                       ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
+                       continue;
+
+               /* found preallocated blocks, use them */
+               spin_lock(&pa->pa_lock);
+               if (pa->pa_deleted == 0 && pa->pa_free) {
+                       atomic_inc(&pa->pa_count);
+                       ext4_mb_use_inode_pa(ac, pa);
+                       spin_unlock(&pa->pa_lock);
+                       ac->ac_criteria = 10;
+                       rcu_read_unlock();
+                       return 1;
+               }
+               spin_unlock(&pa->pa_lock);
+       }
+       rcu_read_unlock();
+
+       /* can we use group allocation? */
+       if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
+               return 0;
+
+       /* inode may have no locality group for some reason */
+       lg = ac->ac_lg;
+       if (lg == NULL)
+               return 0;
+
+       rcu_read_lock();
+       list_for_each_rcu(cur, &lg->lg_prealloc_list) {
+               pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
+               spin_lock(&pa->pa_lock);
+               if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) {
+                       atomic_inc(&pa->pa_count);
+                       ext4_mb_use_group_pa(ac, pa);
+                       spin_unlock(&pa->pa_lock);
+                       ac->ac_criteria = 20;
+                       rcu_read_unlock();
+                       return 1;
+               }
+               spin_unlock(&pa->pa_lock);
+       }
+       rcu_read_unlock();
+
+       return 0;
+}
+
+/*
+ * the function goes through all preallocation in this group and marks them
+ * used in in-core bitmap. buddy must be generated from this bitmap
+ * Need to be called with ext4 group lock (ext4_lock_group)
+ */
+static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
+                                       ext4_group_t group)
+{
+       struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+       struct ext4_prealloc_space *pa;
+       struct list_head *cur;
+       ext4_group_t groupnr;
+       ext4_grpblk_t start;
+       int preallocated = 0;
+       int count = 0;
+       int len;
+
+       /* all form of preallocation discards first load group,
+        * so the only competing code is preallocation use.
+        * we don't need any locking here
+        * notice we do NOT ignore preallocations with pa_deleted
+        * otherwise we could leave used blocks available for
+        * allocation in buddy when concurrent ext4_mb_put_pa()
+        * is dropping preallocation
+        */
+       list_for_each(cur, &grp->bb_prealloc_list) {
+               pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
+               spin_lock(&pa->pa_lock);
+               ext4_get_group_no_and_offset(sb, pa->pa_pstart,
+                                            &groupnr, &start);
+               len = pa->pa_len;
+               spin_unlock(&pa->pa_lock);
+               if (unlikely(len == 0))
+                       continue;
+               BUG_ON(groupnr != group);
+               mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
+                                               bitmap, start, len);
+               preallocated += len;
+               count++;
+       }
+       mb_debug("prellocated %u for group %lu\n", preallocated, group);
+}
+
+static void ext4_mb_pa_callback(struct rcu_head *head)
+{
+       struct ext4_prealloc_space *pa;
+       pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
+       kmem_cache_free(ext4_pspace_cachep, pa);
+}
+
+/*
+ * drops a reference to preallocated space descriptor
+ * if this was the last reference and the space is consumed
+ */
+static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
+                       struct super_block *sb, struct ext4_prealloc_space *pa)
+{
+       unsigned long grp;
+
+       if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
+               return;
+
+       /* in this short window concurrent discard can set pa_deleted */
+       spin_lock(&pa->pa_lock);
+       if (pa->pa_deleted == 1) {
+               spin_unlock(&pa->pa_lock);
+               return;
+       }
+
+       pa->pa_deleted = 1;
+       spin_unlock(&pa->pa_lock);
+
+       /* -1 is to protect from crossing allocation group */
+       ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL);
+
+       /*
+        * possible race:
+        *
+        *  P1 (buddy init)                     P2 (regular allocation)
+        *                                      find block B in PA
+        *  copy on-disk bitmap to buddy
+        *                                      mark B in on-disk bitmap
+        *                                      drop PA from group
+        *  mark all PAs in buddy
+        *
+        * thus, P1 initializes buddy with B available. to prevent this
+        * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
+        * against that pair
+        */
+       ext4_lock_group(sb, grp);
+       list_del(&pa->pa_group_list);
+       ext4_unlock_group(sb, grp);
+
+       spin_lock(pa->pa_obj_lock);
+       list_del_rcu(&pa->pa_inode_list);
+       spin_unlock(pa->pa_obj_lock);
+
+       call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
+}
+
+/*
+ * creates new preallocated space for given inode
+ */
+static int ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
+{
+       struct super_block *sb = ac->ac_sb;
+       struct ext4_prealloc_space *pa;
+       struct ext4_group_info *grp;
+       struct ext4_inode_info *ei;
+
+       /* preallocate only when found space is larger then requested */
+       BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
+       BUG_ON(ac->ac_status != AC_STATUS_FOUND);
+       BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
+
+       pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
+       if (pa == NULL)
+               return -ENOMEM;
+
+       if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
+               int winl;
+               int wins;
+               int win;
+               int offs;
+
+               /* we can't allocate as much as normalizer wants.
+                * so, found space must get proper lstart
+                * to cover original request */
+               BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
+               BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
+
+               /* we're limited by original request in that
+                * logical block must be covered any way
+                * winl is window we can move our chunk within */
+               winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
+
+               /* also, we should cover whole original request */
+               wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
+
+               /* the smallest one defines real window */
+               win = min(winl, wins);
+
+               offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
+               if (offs && offs < win)
+                       win = offs;
+
+               ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
+               BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
+               BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
+       }
+
+       /* preallocation can change ac_b_ex, thus we store actually
+        * allocated blocks for history */
+       ac->ac_f_ex = ac->ac_b_ex;
+
+       pa->pa_lstart = ac->ac_b_ex.fe_logical;
+       pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
+       pa->pa_len = ac->ac_b_ex.fe_len;
+       pa->pa_free = pa->pa_len;
+       atomic_set(&pa->pa_count, 1);
+       spin_lock_init(&pa->pa_lock);
+       pa->pa_deleted = 0;
+       pa->pa_linear = 0;
+
+       mb_debug("new inode pa %p: %llu/%u for %u\n", pa,
+                       pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+
+       ext4_mb_use_inode_pa(ac, pa);
+       atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
+
+       ei = EXT4_I(ac->ac_inode);
+       grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
+
+       pa->pa_obj_lock = &ei->i_prealloc_lock;
+       pa->pa_inode = ac->ac_inode;
+
+       ext4_lock_group(sb, ac->ac_b_ex.fe_group);
+       list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
+       ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
+
+       spin_lock(pa->pa_obj_lock);
+       list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
+       spin_unlock(pa->pa_obj_lock);
+
+       return 0;
+}
+
+/*
+ * creates new preallocated space for locality group inodes belongs to
+ */
+static int ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
+{
+       struct super_block *sb = ac->ac_sb;
+       struct ext4_locality_group *lg;
+       struct ext4_prealloc_space *pa;
+       struct ext4_group_info *grp;
+
+       /* preallocate only when found space is larger then requested */
+       BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
+       BUG_ON(ac->ac_status != AC_STATUS_FOUND);
+       BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
+
+       BUG_ON(ext4_pspace_cachep == NULL);
+       pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
+       if (pa == NULL)
+               return -ENOMEM;
+
+       /* preallocation can change ac_b_ex, thus we store actually
+        * allocated blocks for history */
+       ac->ac_f_ex = ac->ac_b_ex;
+
+       pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
+       pa->pa_lstart = pa->pa_pstart;
+       pa->pa_len = ac->ac_b_ex.fe_len;
+       pa->pa_free = pa->pa_len;
+       atomic_set(&pa->pa_count, 1);
+       spin_lock_init(&pa->pa_lock);
+       pa->pa_deleted = 0;
+       pa->pa_linear = 1;
+
+       mb_debug("new group pa %p: %llu/%u for %u\n", pa,
+                       pa->pa_pstart, pa->pa_len, pa->pa_lstart);
+
+       ext4_mb_use_group_pa(ac, pa);
+       atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
+
+       grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
+       lg = ac->ac_lg;
+       BUG_ON(lg == NULL);
+
+       pa->pa_obj_lock = &lg->lg_prealloc_lock;
+       pa->pa_inode = NULL;
+
+       ext4_lock_group(sb, ac->ac_b_ex.fe_group);
+       list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
+       ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
+
+       spin_lock(pa->pa_obj_lock);
+       list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list);
+       spin_unlock(pa->pa_obj_lock);
+
+       return 0;
+}
+
+static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
+{
+       int err;
+
+       if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
+               err = ext4_mb_new_group_pa(ac);
+       else
+               err = ext4_mb_new_inode_pa(ac);
+       return err;
+}
+
+/*
+ * finds all unused blocks in on-disk bitmap, frees them in
+ * in-core bitmap and buddy.
+ * @pa must be unlinked from inode and group lists, so that
+ * nobody else can find/use it.
+ * the caller MUST hold group/inode locks.
+ * TODO: optimize the case when there are no in-core structures yet
+ */
+static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,
+                               struct buffer_head *bitmap_bh,
+                               struct ext4_prealloc_space *pa)
+{
+       struct ext4_allocation_context ac;
+       struct super_block *sb = e4b->bd_sb;
+       struct ext4_sb_info *sbi = EXT4_SB(sb);
+       unsigned long end;
+       unsigned long next;
+       ext4_group_t group;
+       ext4_grpblk_t bit;
+       sector_t start;
+       int err = 0;
+       int free = 0;
+
+       BUG_ON(pa->pa_deleted == 0);
+       ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
+       BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
+       end = bit + pa->pa_len;
+
+       ac.ac_sb = sb;
+       ac.ac_inode = pa->pa_inode;
+       ac.ac_op = EXT4_MB_HISTORY_DISCARD;
+
+       while (bit < end) {
+               bit = ext4_find_next_zero_bit(bitmap_bh->b_data, end, bit);
+               if (bit >= end)
+                       break;
+               next = ext4_find_next_bit(bitmap_bh->b_data, end, bit);
+               if (next > end)
+                       next = end;
+               start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
+                               le32_to_cpu(sbi->s_es->s_first_data_block);
+               mb_debug("    free preallocated %u/%u in group %u\n",
+                               (unsigned) start, (unsigned) next - bit,
+                               (unsigned) group);
+               free += next - bit;
+
+               ac.ac_b_ex.fe_group = group;
+               ac.ac_b_ex.fe_start = bit;
+               ac.ac_b_ex.fe_len = next - bit;
+               ac.ac_b_ex.fe_logical = 0;
+               ext4_mb_store_history(&ac);
+
+               mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
+               bit = next + 1;
+       }
+       if (free != pa->pa_free) {
+               printk(KERN_ERR "pa %p: logic %lu, phys. %lu, len %lu\n",
+                       pa, (unsigned long) pa->pa_lstart,
+                       (unsigned long) pa->pa_pstart,
+                       (unsigned long) pa->pa_len);
+               printk(KERN_ERR "free %u, pa_free %u\n", free, pa->pa_free);
+       }
+       BUG_ON(free != pa->pa_free);
+       atomic_add(free, &sbi->s_mb_discarded);
+
+       return err;
+}
+
+static int ext4_mb_release_group_pa(struct ext4_buddy *e4b,
+                               struct ext4_prealloc_space *pa)
+{
+       struct ext4_allocation_context ac;
+       struct super_block *sb = e4b->bd_sb;
+       ext4_group_t group;
+       ext4_grpblk_t bit;
+
+       ac.ac_op = EXT4_MB_HISTORY_DISCARD;
+
+       BUG_ON(pa->pa_deleted == 0);
+       ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
+       BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
+       mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
+       atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
+
+       ac.ac_sb = sb;
+       ac.ac_inode = NULL;
+       ac.ac_b_ex.fe_group = group;
+       ac.ac_b_ex.fe_start = bit;
+       ac.ac_b_ex.fe_len = pa->pa_len;
+       ac.ac_b_ex.fe_logical = 0;
+       ext4_mb_store_history(&ac);
+
+       return 0;
+}
+
+/*
+ * releases all preallocations in given group
+ *
+ * first, we need to decide discard policy:
+ * - when do we discard
+ *   1) ENOSPC
+ * - how many do we discard
+ *   1) how many requested
+ */
+static int ext4_mb_discard_group_preallocations(struct super_block *sb,
+                                       ext4_group_t group, int needed)
+{
+       struct ext4_group_info *grp = ext4_get_group_info(sb, group);
+       struct buffer_head *bitmap_bh = NULL;
+       struct ext4_prealloc_space *pa, *tmp;
+       struct list_head list;
+       struct ext4_buddy e4b;
+       int err;
+       int busy = 0;
+       int free = 0;
+
+       mb_debug("discard preallocation for group %lu\n", group);
+
+       if (list_empty(&grp->bb_prealloc_list))
+               return 0;
+
+       bitmap_bh = read_block_bitmap(sb, group);
+       if (bitmap_bh == NULL) {
+               /* error handling here */
+               ext4_mb_release_desc(&e4b);
+               BUG_ON(bitmap_bh == NULL);
+       }
+
+       err = ext4_mb_load_buddy(sb, group, &e4b);
+       BUG_ON(err != 0); /* error handling here */
+
+       if (needed == 0)
+               needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
+
+       grp = ext4_get_group_info(sb, group);
+       INIT_LIST_HEAD(&list);
+
+repeat:
+       ext4_lock_group(sb, group);
+       list_for_each_entry_safe(pa, tmp,
+                               &grp->bb_prealloc_list, pa_group_list) {
+               spin_lock(&pa->pa_lock);
+               if (atomic_read(&pa->pa_count)) {
+                       spin_unlock(&pa->pa_lock);
+                       busy = 1;
+                       continue;
+               }
+               if (pa->pa_deleted) {
+                       spin_unlock(&pa->pa_lock);
+                       continue;
+               }
+
+               /* seems this one can be freed ... */
+               pa->pa_deleted = 1;
+
+               /* we can trust pa_free ... */
+               free += pa->pa_free;
+
+               spin_unlock(&pa->pa_lock);
+
+               list_del(&pa->pa_group_list);
+               list_add(&pa->u.pa_tmp_list, &list);
+       }
+
+       /* if we still need more blocks and some PAs were used, try again */
+       if (free < needed && busy) {
+               busy = 0;
+               ext4_unlock_group(sb, group);
+               /*
+                * Yield the CPU here so that we don't get soft lockup
+                * in non preempt case.
+                */
+               yield();
+               goto repeat;
+       }
+
+       /* found anything to free? */
+       if (list_empty(&list)) {
+               BUG_ON(free != 0);
+               goto out;
+       }
+
+       /* now free all selected PAs */
+       list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
+
+               /* remove from object (inode or locality group) */
+               spin_lock(pa->pa_obj_lock);
+               list_del_rcu(&pa->pa_inode_list);
+               spin_unlock(pa->pa_obj_lock);
+
+               if (pa->pa_linear)
+                       ext4_mb_release_group_pa(&e4b, pa);
+               else
+                       ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
+
+               list_del(&pa->u.pa_tmp_list);
+               call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
+       }
+
+out:
+       ext4_unlock_group(sb, group);
+       ext4_mb_release_desc(&e4b);
+       put_bh(bitmap_bh);
+       return free;
+}
+
+/*
+ * releases all non-used preallocated blocks for given inode
+ *
+ * It's important to discard preallocations under i_data_sem
+ * We don't want another block to be served from the prealloc
+ * space when we are discarding the inode prealloc space.
+ *
+ * FIXME!! Make sure it is valid at all the call sites
+ */
+void ext4_mb_discard_inode_preallocations(struct inode *inode)
+{
+       struct ext4_inode_info *ei = EXT4_I(inode);
+       struct super_block *sb = inode->i_sb;
+       struct buffer_head *bitmap_bh = NULL;
+       struct ext4_prealloc_space *pa, *tmp;
+       ext4_group_t group = 0;
+       struct list_head list;
+       struct ext4_buddy e4b;
+       int err;
+
+       if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) {
+               /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
+               return;
+       }
+
+       mb_debug("discard preallocation for inode %lu\n", inode->i_ino);
+
+       INIT_LIST_HEAD(&list);
+
+repeat:
+       /* first, collect all pa's in the inode */
+       spin_lock(&ei->i_prealloc_lock);
+       while (!list_empty(&ei->i_prealloc_list)) {
+               pa = list_entry(ei->i_prealloc_list.next,
+                               struct ext4_prealloc_space, pa_inode_list);
+               BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
+               spin_lock(&pa->pa_lock);
+               if (atomic_read(&pa->pa_count)) {
+                       /* this shouldn't happen often - nobody should
+                        * use preallocation while we're discarding it */
+                       spin_unlock(&pa->pa_lock);
+                       spin_unlock(&ei->i_prealloc_lock);
+                       printk(KERN_ERR "uh-oh! used pa while discarding\n");
+                       WARN_ON(1);
+                       schedule_timeout_uninterruptible(HZ);
+                       goto repeat;
+
+               }
+               if (pa->pa_deleted == 0) {
+                       pa->pa_deleted = 1;
+                       spin_unlock(&pa->pa_lock);
+                       list_del_rcu(&pa->pa_inode_list);
+                       list_add(&pa->u.pa_tmp_list, &list);
+                       continue;
+               }
+
+               /* someone is deleting pa right now */
+               spin_unlock(&pa->pa_lock);
+               spin_unlock(&ei->i_prealloc_lock);
+
+               /* we have to wait here because pa_deleted
+                * doesn't mean pa is already unlinked from
+                * the list. as we might be called from
+                * ->clear_inode() the inode will get freed
+                * and concurrent thread which is unlinking
+                * pa from inode's list may access already
+                * freed memory, bad-bad-bad */
+
+               /* XXX: if this happens too often, we can
+                * add a flag to force wait only in case
+                * of ->clear_inode(), but not in case of
+                * regular truncate */
+               schedule_timeout_uninterruptible(HZ);
+               goto repeat;
+       }
+       spin_unlock(&ei->i_prealloc_lock);
+
+       list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
+               BUG_ON(pa->pa_linear != 0);
+               ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
+
+               err = ext4_mb_load_buddy(sb, group, &e4b);
+               BUG_ON(err != 0); /* error handling here */
+
+               bitmap_bh = read_block_bitmap(sb, group);
+               if (bitmap_bh == NULL) {
+                       /* error handling here */
+                       ext4_mb_release_desc(&e4b);
+                       BUG_ON(bitmap_bh == NULL);
+               }
+
+               ext4_lock_group(sb, group);
+               list_del(&pa->pa_group_list);
+               ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
+               ext4_unlock_group(sb, group);
+
+               ext4_mb_release_desc(&e4b);
+               put_bh(bitmap_bh);
+
+               list_del(&pa->u.pa_tmp_list);
+               call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
+       }
+}
+
+/*
+ * finds all preallocated spaces and return blocks being freed to them
+ * if preallocated space becomes full (no block is used from the space)
+ * then the function frees space in buddy
+ * XXX: at the moment, truncate (which is the only way to free blocks)
+ * discards all preallocations
+ */
+static void ext4_mb_return_to_preallocation(struct inode *inode,
+                                       struct ext4_buddy *e4b,
+                                       sector_t block, int count)
+{
+       BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
+}
+#ifdef MB_DEBUG
+static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
+{
+       struct super_block *sb = ac->ac_sb;