Merge branch 'linux-2.6'

15 files changed, 6313 insertions, 628 deletions

diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index ae6e7e502ac9..ac6fa8ca0a2f 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -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
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 71ee95e534fd..ac75ea953d83 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -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);
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index f612bef98315..33888bb58144 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -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);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 85287742f2ae..bc7081f1fbe8 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -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;
@@ -1015,13 +1017,157 @@ out:
 }
 
 /*
+ * 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.
  * NOTE: it considers block number from index entry as
  * 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.
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 1a81cd66d63b..ac35ec58db55 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -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.
 	 */
diff --git a/fs/ext4/group.h b/fs/ext4/group.h
index 1577910bb58b..7eb0604e7eea 100644
--- a/fs/ext4/group.h
+++ b/fs/ext4/group.h
@@ -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 */
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c
index c61f37fd3f05..575b5215c808 100644
--- a/fs/ext4/ialloc.c
+++ b/fs/ext4/ialloc.c
@@ -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);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 5489703d9573..bb717cbb749c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -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;
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index e7f894bdb420..2ed7c37f897e 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -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
index 000000000000..76e5fedc0a0b
--- /dev/null
+++ b/fs/ext4/mballoc.c
@@ -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;
+	ext4_group_t i;
+
+	printk(KERN_ERR "EXT4-fs: Can't allocate:"
+			" Allocation context details:\n");
+	printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
+			ac->ac_status, ac->ac_flags);
+	printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
+			"best %lu/%lu/%lu@%lu cr %d\n",
+			(unsigned long)ac->ac_o_ex.fe_group,
+			(unsigned long)ac->ac_o_ex.fe_start,
+			(unsigned long)ac->ac_o_ex.fe_len,
+			(unsigned long)ac->ac_o_ex.fe_logical,
+			(unsigned long)ac->ac_g_ex.fe_group,
+			(unsigned long)ac->ac_g_ex.fe_start,
+			(unsigned long)ac->ac_g_ex.fe_len,
+			(unsigned long)ac->ac_g_ex.fe_logical,
+			(unsigned long)ac->ac_b_ex.fe_group,
+			(unsigned long)ac->ac_b_ex.fe_start,
+			(unsigned long)ac->ac_b_ex.fe_len,
+			(unsigned long)ac->ac_b_ex.fe_logical,
+			(int)ac->ac_criteria);
+	printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
+		ac->ac_found);
+	printk(KERN_ERR "EXT4-fs: groups: \n");
+	for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
+		struct ext4_group_info *grp = ext4_get_group_info(sb, i);
+		struct ext4_prealloc_space *pa;
+		ext4_grpblk_t start;
+		struct list_head *cur;
+		ext4_lock_group(sb, i);
+		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,
+						     NULL, &start);
+			spin_unlock(&pa->pa_lock);
+			printk(KERN_ERR "PA:%lu:%d:%u \n", i,
+							start, pa->pa_len);
+		}
+		ext4_lock_group(sb, i);
+
+		if (grp->bb_free == 0)
+			continue;
+		printk(KERN_ERR "%lu: %d/%d \n",
+		       i, grp->bb_free, grp->bb_fragments);
+	}
+	printk(KERN_ERR "\n");
+}
+#else
+static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
+{
+	return;
+}
+#endif
+
+/*
+ * We use locality group preallocation for small size file. The size of the
+ * file is determined by the current size or the resulting size after
+ * allocation which ever is larger
+ *
+ * One can tune this size via /proc/fs/ext4/<partition>/stream_req
+ */
+static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
+	int bsbits = ac->ac_sb->s_blocksize_bits;
+	loff_t size, isize;
+
+	if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
+		return;
+
+	size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
+	isize = i_size_read(ac->ac_inode) >> bsbits;
+	size = max(size, isize);
+
+	/* don't use group allocation for large files */
+	if (size >= sbi->s_mb_stream_request)
+		return;
+
+	if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
+		return;
+
+	BUG_ON(ac->ac_lg != NULL);
+	/*
+	 * locality group prealloc space are per cpu. The reason for having
+	 * per cpu locality group is to reduce the contention between block
+	 * request from multiple CPUs.
+	 */
+	ac->ac_lg = &sbi->s_locality_groups[get_cpu()];
+	put_cpu();
+
+	/* we're going to use group allocation */
+	ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
+
+	/* serialize all allocations in the group */
+	mutex_lock(&ac->ac_lg->lg_mutex);
+}
+
+static int ext4_mb_initialize_context(struct ext4_allocation_context *ac,
+				struct ext4_allocation_request *ar)
+{
+	struct super_block *sb = ar->inode->i_sb;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_super_block *es = sbi->s_es;
+	ext4_group_t group;
+	unsigned long len;
+	unsigned long goal;
+	ext4_grpblk_t block;
+
+	/* we can't allocate > group size */
+	len = ar->len;
+
+	/* just a dirty hack to filter too big requests  */
+	if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
+		len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
+
+	/* start searching from the goal */
+	goal = ar->goal;
+	if (goal < le32_to_cpu(es->s_first_data_block) ||
+			goal >= ext4_blocks_count(es))
+		goal = le32_to_cpu(es->s_first_data_block);
+	ext4_get_group_no_and_offset(sb, goal, &group, &block);
+
+	/* set up allocation goals */
+	ac->ac_b_ex.fe_logical = ar->logical;
+	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_groups_scanned = 0;
+	ac->ac_ex_scanned = 0;
+	ac->ac_found = 0;
+	ac->ac_sb = sb;
+	ac->ac_inode = ar->inode;
+	ac->ac_o_ex.fe_logical = ar->logical;
+	ac->ac_o_ex.fe_group = group;
+	ac->ac_o_ex.fe_start = block;
+	ac->ac_o_ex.fe_len = len;
+	ac->ac_g_ex.fe_logical = ar->logical;
+	ac->ac_g_ex.fe_group = group;
+	ac->ac_g_ex.fe_start = block;
+	ac->ac_g_ex.fe_len = len;
+	ac->ac_f_ex.fe_len = 0;
+	ac->ac_flags = ar->flags;
+	ac->ac_2order = 0;
+	ac->ac_criteria = 0;
+	ac->ac_pa = NULL;
+	ac->ac_bitmap_page = NULL;
+	ac->ac_buddy_page = NULL;
+	ac->ac_lg = NULL;
+
+	/* we have to define context: we'll we work with a file or
+	 * locality group. this is a policy, actually */
+	ext4_mb_group_or_file(ac);
+
+	mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
+			"left: %u/%u, right %u/%u to %swritable\n",
+			(unsigned) ar->len, (unsigned) ar->logical,
+			(unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
+			(unsigned) ar->lleft, (unsigned) ar->pleft,
+			(unsigned) ar->lright, (unsigned) ar->pright,
+			atomic_read(&ar->inode->i_writecount) ? "" : "non-");
+	return 0;
+
+}
+
+/*
+ * release all resource we used in allocation
+ */
+static int ext4_mb_release_context(struct ext4_allocation_context *ac)
+{
+	if (ac->ac_pa) {
+		if (ac->ac_pa->pa_linear) {
+			/* see comment in ext4_mb_use_group_pa() */
+			spin_lock(&ac->ac_pa->pa_lock);
+			ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len;
+			ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len;
+			ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len;
+			ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len;
+			spin_unlock(&ac->ac_pa->pa_lock);
+		}
+		ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa);
+	}
+	if (ac->ac_bitmap_page)
+		page_cache_release(ac->ac_bitmap_page);
+	if (ac->ac_buddy_page)
+		page_cache_release(ac->ac_buddy_page);
+	if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
+		mutex_unlock(&ac->ac_lg->lg_mutex);
+	ext4_mb_collect_stats(ac);
+	return 0;
+}
+
+static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
+{
+	ext4_group_t i;
+	int ret;
+	int freed = 0;
+
+	for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
+		ret = ext4_mb_discard_group_preallocations(sb, i, needed);
+		freed += ret;
+		needed -= ret;
+	}
+
+	return freed;
+}
+
+/*
+ * Main entry point into mballoc to allocate blocks
+ * it tries to use preallocation first, then falls back
+ * to usual allocation
+ */
+ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
+				 struct ext4_allocation_request *ar, int *errp)
+{
+	struct ext4_allocation_context ac;
+	struct ext4_sb_info *sbi;
+	struct super_block *sb;
+	ext4_fsblk_t block = 0;
+	int freed;
+	int inquota;
+
+	sb = ar->inode->i_sb;
+	sbi = EXT4_SB(sb);
+
+	if (!test_opt(sb, MBALLOC)) {
+		block = ext4_new_blocks_old(handle, ar->inode, ar->goal,
+					    &(ar->len), errp);
+		return block;
+	}
+
+	while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
+		ar->flags |= EXT4_MB_HINT_NOPREALLOC;
+		ar->len--;
+	}
+	if (ar->len == 0) {
+		*errp = -EDQUOT;
+		return 0;
+	}
+	inquota = ar->len;
+
+	ext4_mb_poll_new_transaction(sb, handle);
+
+	*errp = ext4_mb_initialize_context(&ac, ar);
+	if (*errp) {
+		ar->len = 0;
+		goto out;
+	}
+
+	ac.ac_op = EXT4_MB_HISTORY_PREALLOC;
+	if (!ext4_mb_use_preallocated(&ac)) {
+
+		ac.ac_op = EXT4_MB_HISTORY_ALLOC;
+		ext4_mb_normalize_request(&ac, ar);
+
+repeat:
+		/* allocate space in core */
+		ext4_mb_regular_allocator(&ac);
+
+		/* as we've just preallocated more space than
+		 * user requested orinally, we store allocated
+		 * space in a special descriptor */
+		if (ac.ac_status == AC_STATUS_FOUND &&
+				ac.ac_o_ex.fe_len < ac.ac_b_ex.fe_len)
+			ext4_mb_new_preallocation(&ac);
+	}
+
+	if (likely(ac.ac_status == AC_STATUS_FOUND)) {
+		ext4_mb_mark_diskspace_used(&ac, handle);
+		*errp = 0;
+		block = ext4_grp_offs_to_block(sb, &ac.ac_b_ex);
+		ar->len = ac.ac_b_ex.fe_len;
+	} else {
+		freed  = ext4_mb_discard_preallocations(sb, ac.ac_o_ex.fe_len);
+		if (freed)
+			goto repeat;
+		*errp = -ENOSPC;
+		ac.ac_b_ex.fe_len = 0;
+		ar->len = 0;
+		ext4_mb_show_ac(&ac);
+	}
+
+	ext4_mb_release_context(&ac);
+
+out:
+	if (ar->len < inquota)
+		DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
+
+	return block;
+}
+static void ext4_mb_poll_new_transaction(struct super_block *sb,
+						handle_t *handle)
+{
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+
+	if (sbi->s_last_transaction == handle->h_transaction->t_tid)
+		return;
+
+	/* new transaction! time to close last one and free blocks for
+	 * committed transaction. we know that only transaction can be
+	 * active, so previos transaction can be being logged and we
+	 * know that transaction before previous is known to be already
+	 * logged. this means that now we may free blocks freed in all
+	 * transactions before previous one. hope I'm clear enough ... */
+
+	spin_lock(&sbi->s_md_lock);
+	if (sbi->s_last_transaction != handle->h_transaction->t_tid) {
+		mb_debug("new transaction %lu, old %lu\n",
+				(unsigned long) handle->h_transaction->t_tid,
+				(unsigned long) sbi->s_last_transaction);
+		list_splice_init(&sbi->s_closed_transaction,
+				&sbi->s_committed_transaction);
+		list_splice_init(&sbi->s_active_transaction,
+				&sbi->s_closed_transaction);
+		sbi->s_last_transaction = handle->h_transaction->t_tid;
+	}
+	spin_unlock(&sbi->s_md_lock);
+
+	ext4_mb_free_committed_blocks(sb);
+}
+
+static int ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
+			  ext4_group_t group, ext4_grpblk_t block, int count)
+{
+	struct ext4_group_info *db = e4b->bd_info;
+	struct super_block *sb = e4b->bd_sb;
+	struct ext4_sb_info *sbi = EXT4_SB(sb);
+	struct ext4_free_metadata *md;
+	int i;
+
+	BUG_ON(e4b->bd_bitmap_page == NULL);
+	BUG_ON(e4b->bd_buddy_page == NULL);
+
+	ext4_lock_group(sb, group);
+	for (i = 0; i < count; i++) {
+		md = db->bb_md_cur;
+		if (md && db->bb_tid != handle->h_transaction->t_tid) {
+			db->bb_md_cur = NULL;
+			md = NULL;
+		}
+
+		if (md == NULL) {
+			ext4_unlock_group(sb, group);
+			md = kmalloc(sizeof(*md), GFP_NOFS);
+			if (md == NULL)
+				return -ENOMEM;
+			md->num = 0;
+			md->group = group;
+
+			ext4_lock_group(sb, group);
+			if (db->bb_md_cur == NULL) {
+				spin_lock(&sbi->s_md_lock);
+				list_add(&md->list, &sbi->s_active_transaction);
+				spin_unlock(&sbi->s_md_lock);
+				/* protect buddy cache from being freed,
+				 * otherwise we'll refresh it from
+				 * on-disk bitmap and lose not-yet-available
+				 * blocks */
+				page_cache_get(e4b->bd_buddy_page);
+				page_cache_get(e4b->bd_bitmap_page);
+				db->bb_md_cur = md;
+				db->bb_tid = handle->h_transaction->t_tid;
+				mb_debug("new md 0x%p for group %lu\n",
+						md, md->group);
+			} else {
+				kfree(md);
+				md = db->bb_md_cur;
+			}
+		}
+
+		BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS);
+		md->blocks[md->num] = block + i;
+		md->num++;
+		if (md->num == EXT4_BB_MAX_BLOCKS) {
+			/* no more space, put full container on a sb's list */
+			db->bb_md_cur = NULL;
+		}
+	}
+	ext4_unlock_group(sb, group);
+	return 0;
+}
+
+/*
+ * Main entry point into mballoc to free blocks
+ */
+void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
+			unsigned long block, unsigned long count,
+			int metadata, unsigned long *freed)
+{
+	struct buffer_head *bitmap_bh = 0;
+	struct super_block *sb = inode->i_sb;
+	struct ext4_allocation_context ac;
+	struct ext4_group_desc *gdp;
+	struct ext4_super_block *es;
+	unsigned long overflow;
+	ext4_grpblk_t bit;
+	struct buffer_head *gd_bh;
+	ext4_group_t block_group;
+	struct ext4_sb_info *sbi;
+	struct ext4_buddy e4b;
+	int err = 0;
+	int ret;
+
+	*freed = 0;
+
+	ext4_mb_poll_new_transaction(sb, handle);
+
+	sbi = EXT4_SB(sb);
+	es = EXT4_SB(sb)->s_es;
+	if (block < le32_to_cpu(es->s_first_data_block) ||
+	    block + count < block ||
+	    block + count > ext4_blocks_count(es)) {
+		ext4_error(sb, __FUNCTION__,
+			    "Freeing blocks not in datazone - "
+			    "block = %lu, count = %lu", block, count);
+		goto error_return;
+	}
+
+	ext4_debug("freeing block %lu\n", block);
+
+	ac.ac_op = EXT4_MB_HISTORY_FREE;
+	ac.ac_inode = inode;
+	ac.ac_sb = sb;
+
+do_more:
+	overflow = 0;
+	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
+
+	/*
+	 * Check to see if we are freeing blocks across a group
+	 * boundary.
+	 */
+	if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
+		overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
+		count -= overflow;
+	}
+	bitmap_bh = read_block_bitmap(sb, block_group);
+	if (!bitmap_bh)
+		goto error_return;
+	gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
+	if (!gdp)
+		goto error_return;
+
+	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
+	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
+	    in_range(block, ext4_inode_table(sb, gdp),
+		      EXT4_SB(sb)->s_itb_per_group) ||
+	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
+		      EXT4_SB(sb)->s_itb_per_group)) {
+
+		ext4_error(sb, __FUNCTION__,
+			   "Freeing blocks in system zone - "
+			   "Block = %lu, count = %lu", block, count);
+	}
+
+	BUFFER_TRACE(bitmap_bh, "getting write access");
+	err = ext4_journal_get_write_access(handle, bitmap_bh);
+	if (err)
+		goto error_return;
+
+	/*
+	 * We are about to modify some metadata.  Call the journal APIs
+	 * to unshare ->b_data if a currently-committing transaction is
+	 * using it
+	 */
+	BUFFER_TRACE(gd_bh, "get_write_access");
+	err = ext4_journal_get_write_access(handle, gd_bh);
+	if (err)
+		goto error_return;
+
+	err = ext4_mb_load_buddy(sb, block_group, &e4b);
+	if (err)
+		goto error_return;
+
+#ifdef AGGRESSIVE_CHECK
+	{
+		int i;
+		for (i = 0; i < count; i++)
+			BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
+	}
+#endif
+	mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
+			bit, count);
+
+	/* We dirtied the bitmap block */
+	BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
+	err = ext4_journal_dirty_metadata(handle, bitmap_bh);
+
+	ac.ac_b_ex.fe_group = block_group;
+	ac.ac_b_ex.fe_start = bit;
+	ac.ac_b_ex.fe_len = count;
+	ext4_mb_store_history(&ac);
+
+	if (metadata) {
+		/* blocks being freed are metadata. these blocks shouldn't
+		 * be used until this transaction is committed */
+		ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
+	} else {
+		ext4_lock_group(sb, block_group);
+		err = mb_free_blocks(inode, &e4b, bit, count);
+		ext4_mb_return_to_preallocation(inode, &e4b, block, count);
+		ext4_unlock_group(sb, block_group);
+		BUG_ON(err != 0);
+	}
+
+	spin_lock(sb_bgl_lock(sbi, block_group));
+	gdp->bg_free_blocks_count =
+		cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) + count);
+	gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
+	spin_unlock(sb_bgl_lock(sbi, block_group));
+	percpu_counter_add(&sbi->s_freeblocks_counter, count);
+
+	ext4_mb_release_desc(&e4b);
+
+	*freed += count;
+
+	/* And the group descriptor block */
+	BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
+	ret = ext4_journal_dirty_metadata(handle, gd_bh);
+	if (!err)
+		err = ret;
+
+	if (overflow && !err) {
+		block += count;
+		count = overflow;
+		put_bh(bitmap_bh);
+		goto do_more;
+	}
+	sb->s_dirt = 1;
+error_return:
+	brelse(bitmap_bh);
+	ext4_std_error(sb, err);
+	return;
+}
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
new file mode 100644
index 000000000000..3ebc2332f52e
--- /dev/null
+++ b/fs/ext4/migrate.c
@@ -0,0 +1,560 @@
+/*
+ * Copyright IBM Corporation, 2007
+ * Author Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2.1 of the GNU Lesser General Public License
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/ext4_jbd2.h>
+#include <linux/ext4_fs_extents.h>
+
+/*
+ * The contiguous blocks details which can be
+ * represented by a single extent
+ */
+struct list_blocks_struct {
+	ext4_lblk_t first_block, last_block;
+	ext4_fsblk_t first_pblock, last_pblock;
+};
+
+static int finish_range(handle_t *handle, struct inode *inode,
+				struct list_blocks_struct *lb)
+
+{
+	int retval = 0, needed;
+	struct ext4_extent newext;
+	struct ext4_ext_path *path;
+	if (lb->first_pblock == 0)
+		return 0;
+
+	/* Add the extent to temp inode*/
+	newext.ee_block = cpu_to_le32(lb->first_block);
+	newext.ee_len   = cpu_to_le16(lb->last_block - lb->first_block + 1);
+	ext4_ext_store_pblock(&newext, lb->first_pblock);
+	path = ext4_ext_find_extent(inode, lb->first_block, NULL);
+
+	if (IS_ERR(path)) {
+		retval = PTR_ERR(path);
+		goto err_out;
+	}
+
+	/*
+	 * Calculate the credit needed to inserting this extent
+	 * Since we are doing this in loop we may accumalate extra
+	 * credit. But below we try to not accumalate too much
+	 * of them by restarting the journal.
+	 */
+	needed = ext4_ext_calc_credits_for_insert(inode, path);
+
+	/*
+	 * Make sure the credit we accumalated is not really high
+	 */
+	if (needed && handle->h_buffer_credits >= EXT4_RESERVE_TRANS_BLOCKS) {
+		retval = ext4_journal_restart(handle, needed);
+		if (retval)
+			goto err_out;
+	}
+	if (needed) {
+		retval = ext4_journal_extend(handle, needed);
+		if (retval != 0) {
+			/*
+			 * IF not able to extend the journal restart the journal
+			 */
+			retval = ext4_journal_restart(handle, needed);
+			if (retval)
+				goto err_out;
+		}
+	}
+	retval = ext4_ext_insert_extent(handle, inode, path, &newext);
+err_out:
+	lb->first_pblock = 0;
+	return retval;
+}
+
+static int update_extent_range(handle_t *handle, struct inode *inode,
+				ext4_fsblk_t pblock, ext4_lblk_t blk_num,
+				struct list_blocks_struct *lb)
+{
+	int retval;
+	/*
+	 * See if we can add on to the existing range (if it exists)
+	 */
+	if (lb->first_pblock &&
+		(lb->last_pblock+1 == pblock) &&
+		(lb->last_block+1 == blk_num)) {
+		lb->last_pblock = pblock;
+		lb->last_block = blk_num;
+		return 0;
+	}
+	/*
+	 * Start a new range.
+	 */
+	retval = finish_range(handle, inode, lb);
+	lb->first_pblock = lb->last_pblock = pblock;
+	lb->first_block = lb->last_block = blk_num;
+
+	return retval;
+}
+
+static int update_ind_extent_range(handle_t *handle, struct inode *inode,
+				   ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
+				   struct list_blocks_struct *lb)
+{
+	struct buffer_head *bh;
+	__le32 *i_data;
+	int i, retval = 0;
+	ext4_lblk_t blk_count = *blk_nump;
+	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
+
+	if (!pblock) {
+		/* Only update the file block number */
+		*blk_nump += max_entries;
+		return 0;
+	}
+
+	bh = sb_bread(inode->i_sb, pblock);
+	if (!bh)
+		return -EIO;
+
+	i_data = (__le32 *)bh->b_data;
+	for (i = 0; i < max_entries; i++, blk_count++) {
+		if (i_data[i]) {
+			retval = update_extent_range(handle, inode,
+						le32_to_cpu(i_data[i]),
+						blk_count, lb);
+			if (retval)
+				break;
+		}
+	}
+
+	/* Update the file block number */
+	*blk_nump = blk_count;
+	put_bh(bh);
+	return retval;
+
+}
+
+static int update_dind_extent_range(handle_t *handle, struct inode *inode,
+				    ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
+				    struct list_blocks_struct *lb)
+{
+	struct buffer_head *bh;
+	__le32 *i_data;
+	int i, retval = 0;
+	ext4_lblk_t blk_count = *blk_nump;
+	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
+
+	if (!pblock) {
+		/* Only update the file block number */
+		*blk_nump += max_entries * max_entries;
+		return 0;
+	}
+	bh = sb_bread(inode->i_sb, pblock);
+	if (!bh)
+		return -EIO;
+
+	i_data = (__le32 *)bh->b_data;
+	for (i = 0; i < max_entries; i++) {
+		if (i_data[i]) {
+			retval = update_ind_extent_range(handle, inode,
+						le32_to_cpu(i_data[i]),
+						&blk_count, lb);
+			if (retval)
+				break;
+		} else {
+			/* Only update the file block number */
+			blk_count += max_entries;
+		}
+	}
+
+	/* Update the file block number */
+	*blk_nump = blk_count;
+	put_bh(bh);
+	return retval;
+
+}
+
+static int update_tind_extent_range(handle_t *handle, struct inode *inode,
+				     ext4_fsblk_t pblock, ext4_lblk_t *blk_nump,
+				     struct list_blocks_struct *lb)
+{
+	struct buffer_head *bh;
+	__le32 *i_data;
+	int i, retval = 0;
+	ext4_lblk_t blk_count = *blk_nump;
+	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
+
+	if (!pblock) {
+		/* Only update the file block number */
+		*blk_nump += max_entries * max_entries * max_entries;
+		return 0;
+	}
+	bh = sb_bread(inode->i_sb, pblock);
+	if (!bh)
+		return -EIO;
+
+	i_data = (__le32 *)bh->b_data;
+	for (i = 0; i < max_entries; i++) {
+		if (i_data[i]) {
+			retval = update_dind_extent_range(handle, inode,
+						le32_to_cpu(i_data[i]),
+						&blk_count, lb);
+			if (retval)
+				break;
+		} else
+			/* Only update the file block number */
+			blk_count += max_entries * max_entries;
+	}
+	/* Update the file block number */
+	*blk_nump = blk_count;
+	put_bh(bh);
+	return retval;
+
+}
+
+static int free_dind_blocks(handle_t *handle,
+				struct inode *inode, __le32 i_data)
+{
+	int i;
+	__le32 *tmp_idata;
+	struct buffer_head *bh;
+	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
+
+	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
+	if (!bh)
+		return -EIO;
+
+	tmp_idata = (__le32 *)bh->b_data;
+	for (i = 0; i < max_entries; i++) {
+		if (tmp_idata[i])
+			ext4_free_blocks(handle, inode,
+					le32_to_cpu(tmp_idata[i]), 1, 1);
+	}
+	put_bh(bh);
+	ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);
+	return 0;
+}
+
+static int free_tind_blocks(handle_t *handle,
+				struct inode *inode, __le32 i_data)
+{
+	int i, retval = 0;
+	__le32 *tmp_idata;
+	struct buffer_head *bh;
+	unsigned long max_entries = inode->i_sb->s_blocksize >> 2;
+
+	bh = sb_bread(inode->i_sb, le32_to_cpu(i_data));
+	if (!bh)
+		return -EIO;
+
+	tmp_idata = (__le32 *)bh->b_data;
+	for (i = 0; i < max_entries; i++) {
+		if (tmp_idata[i]) {
+			retval = free_dind_blocks(handle,
+					inode, tmp_idata[i]);
+			if (retval) {
+				put_bh(bh);
+				return retval;
+			}
+		}
+	}
+	put_bh(bh);
+	ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);
+	return 0;
+}
+
+static int free_ind_block(handle_t *handle, struct inode *inode)
+{
+	int retval;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+
+	if (ei->i_data[EXT4_IND_BLOCK])
+		ext4_free_blocks(handle, inode,
+				le32_to_cpu(ei->i_data[EXT4_IND_BLOCK]), 1, 1);
+
+	if (ei->i_data[EXT4_DIND_BLOCK]) {
+		retval = free_dind_blocks(handle, inode,
+						ei->i_data[EXT4_DIND_BLOCK]);
+		if (retval)
+			return retval;
+	}
+
+	if (ei->i_data[EXT4_TIND_BLOCK]) {
+		retval = free_tind_blocks(handle, inode,
+						ei->i_data[EXT4_TIND_BLOCK]);
+		if (retval)
+			return retval;
+	}
+	return 0;
+}
+
+static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
+				struct inode *tmp_inode, int retval)
+{
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	struct ext4_inode_info *tmp_ei = EXT4_I(tmp_inode);
+
+	retval = free_ind_block(handle, inode);
+	if (retval)
+		goto err_out;
+
+	/*
+	 * One credit accounted for writing the
+	 * i_data field of the original inode
+	 */
+	retval = ext4_journal_extend(handle, 1);
+	if (retval != 0) {
+		retval = ext4_journal_restart(handle, 1);
+		if (retval)
+			goto err_out;
+	}
+
+	/*
+	 * We have the extent map build with the tmp inode.
+	 * Now copy the i_data across
+	 */
+	ei->i_flags |= EXT4_EXTENTS_FL;
+	memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
+
+	/*
+	 * Update i_blocks with the new blocks that got
+	 * allocated while adding extents for extent index
+	 * blocks.
+	 *
+	 * While converting to extents we need not
+	 * update the orignal inode i_blocks for extent blocks
+	 * via quota APIs. The quota update happened via tmp_inode already.
+	 */
+	spin_lock(&inode->i_lock);
+	inode->i_blocks += tmp_inode->i_blocks;
+	spin_unlock(&inode->i_lock);
+
+	ext4_mark_inode_dirty(handle, inode);
+err_out:
+	return retval;
+}
+
+static int free_ext_idx(handle_t *handle, struct inode *inode,
+					struct ext4_extent_idx *ix)
+{
+	int i, retval = 0;
+	ext4_fsblk_t block;
+	struct buffer_head *bh;
+	struct ext4_extent_header *eh;
+
+	block = idx_pblock(ix);
+	bh = sb_bread(inode->i_sb, block);
+	if (!bh)
+		return -EIO;
+
+	eh = (struct ext4_extent_header *)bh->b_data;
+	if (eh->eh_depth != 0) {
+		ix = EXT_FIRST_INDEX(eh);
+		for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
+			retval = free_ext_idx(handle, inode, ix);
+			if (retval)
+				break;
+		}
+	}
+	put_bh(bh);
+	ext4_free_blocks(handle, inode, block, 1, 1);
+	return retval;
+}
+
+/*
+ * Free the extent meta data blocks only
+ */
+static int free_ext_block(handle_t *handle, struct inode *inode)
+{
+	int i, retval = 0;
+	struct ext4_inode_info *ei = EXT4_I(inode);
+	struct ext4_extent_header *eh = (struct ext4_extent_header *)ei->i_data;
+	struct ext4_extent_idx *ix;
+	if (eh->eh_depth == 0)
+		/*
+		 * No extra blocks allocated for extent meta data
+		 */
+		return 0;
+	ix = EXT_FIRST_INDEX(eh);
+	for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ix++) {
+		retval = free_ext_idx(handle, inode, ix);
+		if (retval)
+			return retval;
+	}
+	return retval;
+
+}
+
+int ext4_ext_migrate(struct inode *inode, struct file *filp,
+				unsigned int cmd, unsigned long arg)
+{
+	handle_t *handle;
+	int retval = 0, i;
+	__le32 *i_data;
+	ext4_lblk_t blk_count = 0;
+	struct ext4_inode_info *ei;
+	struct inode *tmp_inode = NULL;
+	struct list_blocks_struct lb;
+	unsigned long max_entries;
+
+	if (!test_opt(inode->i_sb, EXTENTS))
+		/*
+		 * if mounted with noextents we don't allow the migrate
+		 */
+		return -EINVAL;
+
+	if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
+		return -EINVAL;
+
+	down_write(&EXT4_I(inode)->i_data_sem);
+	handle = ext4_journal_start(inode,
+					EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
+					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
+					2 * EXT4_QUOTA_INIT_BLOCKS(inode->i_sb)
+					+ 1);
+	if (IS_ERR(handle)) {
+		retval = PTR_ERR(handle);
+		goto err_out;
+	}
+	tmp_inode = ext4_new_inode(handle,
+				inode->i_sb->s_root->d_inode,
+				S_IFREG);
+	if (IS_ERR(tmp_inode)) {
+		retval = -ENOMEM;
+		ext4_journal_stop(handle);
+		tmp_inode = NULL;
+		goto err_out;
+	}
+	i_size_write(tmp_inode, i_size_read(inode));
+	/*
+	 * We don't want the inode to be reclaimed
+	 * if we got interrupted in between. We have
+	 * this tmp inode carrying reference to the
+	 * data blocks of the original file. We set
+	 * the i_nlink to zero at the last stage after
+	 * switching the original file to extent format
+	 */
+	tmp_inode->i_nlink = 1;
+
+	ext4_ext_tree_init(handle, tmp_inode);
+	ext4_orphan_add(handle, tmp_inode);
+	ext4_journal_stop(handle);
+
+	ei = EXT4_I(inode);
+	i_data = ei->i_data;
+	memset(&lb, 0, sizeof(lb));
+
+	/* 32 bit block address 4 bytes */
+	max_entries = inode->i_sb->s_blocksize >> 2;
+
+	/*
+	 * start with one credit accounted for
+	 * superblock modification.
+	 *
+	 * For the tmp_inode we already have commited the
+	 * trascation that created the inode. Later as and
+	 * when we add extents we extent the journal
+	 */
+	handle = ext4_journal_start(inode, 1);
+	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
+		if (i_data[i]) {
+			retval = update_extent_range(handle, tmp_inode,
+						le32_to_cpu(i_data[i]),
+						blk_count, &lb);
+			if (retval)
+				goto err_out;
+		}
+	}
+	if (i_data[EXT4_IND_BLOCK]) {
+		retval = update_ind_extent_range(handle, tmp_inode,
+					le32_to_cpu(i_data[EXT4_IND_BLOCK]),
+					&blk_count, &lb);
+			if (retval)
+				goto err_out;
+	} else
+		blk_count +=  max_entries;
+	if (i_data[EXT4_DIND_BLOCK]) {
+		retval = update_dind_extent_range(handle, tmp_inode,
+					le32_to_cpu(i_data[EXT4_DIND_BLOCK]),
+					&blk_count, &lb);
+			if (retval)
+				goto err_out;
+	} else
+		blk_count += max_entries * max_entries;
+	if (i_data[EXT4_TIND_BLOCK]) {
+		retval = update_tind_extent_range(handle, tmp_inode,
+					le32_to_cpu(i_data[EXT4_TIND_BLOCK]),
+					&blk_count, &lb);
+			if (retval)
+				goto err_out;
+	}
+	/*
+	 * Build the last extent
+	 */
+	retval = finish_range(handle, tmp_inode, &lb);
+err_out:
+	/*
+	 * We are either freeing extent information or indirect
+	 * blocks. During this we touch superblock, group descriptor
+	 * and block bitmap. Later we mark the tmp_inode dirty
+	 * via ext4_ext_tree_init. So allocate a credit of 4
+	 * We may update quota (user and group).
+	 *
+	 * FIXME!! we may be touching bitmaps in different block groups.
+	 */
+	if (ext4_journal_extend(handle,
+			4 + 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb)) != 0)
+		ext4_journal_restart(handle,
+				4 + 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb));
+	if (retval)
+		/*
+		 * Failure case delete the extent information with the
+		 * tmp_inode
+		 */
+		free_ext_block(handle, tmp_inode);
+	else
+		retval = ext4_ext_swap_inode_data(handle, inode,
+							tmp_inode, retval);
+
+	/*
+	 * Mark the tmp_inode as of size zero
+	 */
+	i_size_write(tmp_inode, 0);
+
+	/*
+	 * set the  i_blocks count to zero
+	 * so that the ext4_delete_inode does the
+	 * right job
+	 *
+	 * We don't need to take the i_lock because
+	 * the inode is not visible to user space.
+	 */
+	tmp_inode->i_blocks = 0;
+
+	/* Reset the extent details */
+	ext4_ext_tree_init(handle, tmp_inode);
+
+	/*
+	 * Set the i_nlink to zero so that
+	 * generic_drop_inode really deletes the
+	 * inode
+	 */
+	tmp_inode->i_nlink = 0;
+
+	ext4_journal_stop(handle);
+
+	up_write(&EXT4_I(inode)->i_data_sem);
+
+	if (tmp_inode)
+		iput(tmp_inode);
+
+	return retval;
+}
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 94ee6f315dc1..67b6d8a1ceff 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -51,7 +51,7 @@
 
 static struct buffer_head *ext4_append(handle_t *handle,
 					struct inode *inode,
-					u32 *block, int *err)
+					ext4_lblk_t *block, int *err)
 {
 	struct buffer_head *bh;
 
@@ -144,8 +144,8 @@ struct dx_map_entry
 	u16 size;
 };
 
-static inline unsigned dx_get_block (struct dx_entry *entry);
-static void dx_set_block (struct dx_entry *entry, unsigned value);
+static inline ext4_lblk_t dx_get_block(struct dx_entry *entry);
+static void dx_set_block(struct dx_entry *entry, ext4_lblk_t value);
 static inline unsigned dx_get_hash (struct dx_entry *entry);
 static void dx_set_hash (struct dx_entry *entry, unsigned value);
 static unsigned dx_get_count (struct dx_entry *entries);
@@ -166,7 +166,8 @@ static void dx_sort_map(struct dx_map_entry *map, unsigned count);
 static struct ext4_dir_entry_2 *dx_move_dirents (char *from, char *to,
 		struct dx_map_entry *offsets, int count);
 static struct ext4_dir_entry_2* dx_pack_dirents (char *base, int size);
-static void dx_insert_block (struct dx_frame *frame, u32 hash, u32 block);
+static void dx_insert_block(struct dx_frame *frame,
+					u32 hash, ext4_lblk_t block);
 static int ext4_htree_next_block(struct inode *dir, __u32 hash,
 				 struct dx_frame *frame,
 				 struct dx_frame *frames,
@@ -181,12 +182,12 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
  * Mask them off for now.
  */
 
-static inline unsigned dx_get_block (struct dx_entry *entry)
+static inline ext4_lblk_t dx_get_block(struct dx_entry *entry)
 {
 	return le32_to_cpu(entry->block) & 0x00ffffff;
 }
 
-static inline void dx_set_block (struct dx_entry *entry, unsigned value)
+static inline void dx_set_block(struct dx_entry *entry, ext4_lblk_t value)
 {
 	entry->block = cpu_to_le32(value);
 }
@@ -243,8 +244,8 @@ static void dx_show_index (char * label, struct dx_entry *entries)
 	int i, n = dx_get_count (entries);
 	printk("%s index ", label);
 	for (i = 0; i < n; i++) {
-		printk("%x->%u ", i? dx_get_hash(entries + i) :
-				0, dx_get_block(entries + i));
+		printk("%x->%lu ", i? dx_get_hash(entries + i) :
+				0, (unsigned long)dx_get_block(entries + i));
 	}
 	printk("\n");
 }
@@ -280,7 +281,7 @@ static struct stats dx_show_leaf(struct dx_hash_info *hinfo, struct ext4_dir_ent
 			space += EXT4_DIR_REC_LEN(de->name_len);
 			names++;
 		}
-		de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
+		de = ext4_next_entry(de);
 	}
 	printk("(%i)\n", names);
 	return (struct stats) { names, space, 1 };
@@ -297,7 +298,8 @@ struct stats dx_show_entries(struct dx_hash_info *hinfo, struct inode *dir,
 	printk("%i indexed blocks...\n", count);
 	for (i = 0; i < count; i++, entries++)
 	{
-		u32 block = dx_get_block(entries), hash = i? dx_get_hash(entries): 0;
+		ext4_lblk_t block = dx_get_block(entries);
+		ext4_lblk_t hash  = i ? dx_get_hash(entries): 0;
 		u32 range = i < count - 1? (dx_get_hash(entries + 1) - hash): ~hash;
 		struct stats stats;
 		printk("%s%3u:%03u hash %8x/%8x ",levels?"":"   ", i, block, hash, range);
@@ -551,7 +553,8 @@ static int ext4_htree_next_block(struct inode *dir, __u32 hash,
  */
 static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *p)
 {
-	return (struct ext4_dir_entry_2 *)((char*)p + le16_to_cpu(p->rec_len));
+	return (struct ext4_dir_entry_2 *)((char *)p +
+		ext4_rec_len_from_disk(p->rec_len));
 }
 
 /*
@@ -560,7 +563,7 @@ static inline struct ext4_dir_entry_2 *ext4_next_entry(struct ext4_dir_entry_2 *
  * into the tree.  If there is an error it is returned in err.
  */
 static int htree_dirblock_to_tree(struct file *dir_file,
-				  struct inode *dir, int block,
+				  struct inode *dir, ext4_lblk_t block,
 				  struct dx_hash_info *hinfo,
 				  __u32 start_hash, __u32 start_minor_hash)
 {
@@ -568,7 +571,8 @@ static int htree_dirblock_to_tree(struct file *dir_file,
 	struct ext4_dir_entry_2 *de, *top;
 	int err, count = 0;
 
-	dxtrace(printk("In htree dirblock_to_tree: block %d\n", block));
+	dxtrace(printk(KERN_INFO "In htree dirblock_to_tree: block %lu\n",
+							(unsigned long)block));
 	if (!(bh = ext4_bread (NULL, dir, block, 0, &err)))
 		return err;
 
@@ -620,9 +624,9 @@ int ext4_htree_fill_tree(struct file *dir_file, __u32 start_hash,
 	struct ext4_dir_entry_2 *de;
 	struct dx_frame frames[2], *frame;
 	struct inode *dir;
-	int block, err;
+	ext4_lblk_t block;
 	int count = 0;
-	int ret;
+	int ret, err;
 	__u32 hashval;
 
 	dxtrace(printk("In htree_fill_tree, start hash: %x:%x\n", start_hash,
@@ -720,7 +724,7 @@ static int dx_make_map (struct ext4_dir_entry_2 *de, int size,
 			cond_resched();
 		}
 		/* XXX: do we need to check rec_len == 0 case? -Chris */
-		de = (struct ext4_dir_entry_2 *) ((char *) de + le16_to_cpu(de->rec_len));
+		de = ext4_next_entry(de);
 	}
 	return count;
 }
@@ -752,7 +756,7 @@ static void dx_sort_map (struct dx_map_entry *map, unsigned count)
 	} while(more);
 }
 
-static void dx_insert_block(struct dx_frame *frame, u32 hash, u32 block)
+static void dx_insert_block(struct dx_frame *frame, u32 hash, ext4_lblk_t block)
 {
 	struct dx_entry *entries = frame->entries;
 	struct dx_entry *old = frame->at, *new = old + 1;
@@ -820,7 +824,7 @@ static inline int search_dirblock(struct buffer_head * bh,
 			return 1;
 		}
 		/* prevent looping on a bad block */
-		de_len = le16_to_cpu(de->rec_len);
+		de_len = ext4_rec_len_from_disk(de->rec_len);
 		if (de_len <= 0)
 			return -1;
 		offset += de_len;
@@ -847,23 +851,20 @@ static struct buffer_head * ext4_find_entry (struct dentry *dentry,
 	struct super_block * sb;
 	struct buffer_head * bh_use[NAMEI_RA_SIZE];
 	struct buffer_head * bh, *ret = NULL;
-	unsigned long start, block, b;
+	ext4_lblk_t start, block, b;
 	int ra_max = 0;		/* Number of bh's in the readahead
 				   buffer, bh_use[] */
 	int ra_ptr = 0;		/* Current index into readahead
 				   buffer */
 	int num = 0;
-	int nblocks, i, err;
+	ext4_lblk_t  nblocks;
+	int i, err;
 	struct inode *dir = dentry->d_parent->d_inode;
 	int namelen;
-	const u8 *name;
-	unsigned blocksize;
 
 	*res_dir = NULL;
 	sb = dir->i_sb;
-	blocksize = sb->s_blocksize;
 	namelen = dentry->d_name.len;
-	name = dentry->d_name.name;
 	if (namelen > EXT4_NAME_LEN)
 		return NULL;
 	if (is_dx(dir)) {
@@ -914,7 +915,8 @@ restart:
 		if (!buffer_uptodate(bh)) {
 			/* read error, skip block & hope for the best */
 			ext4_error(sb, __FUNCTION__, "reading directory #%lu "
-				   "offset %lu", dir->i_ino, block);
+				   "offset %lu", dir->i_ino,
+				   (unsigned long)block);
 			brelse(bh);
 			goto next;
 		}
@@ -961,7 +963,7 @@ static struct buffer_head * ext4_dx_find_entry(struct dentry *dentry,
 	struct dx_frame frames[2], *frame;
 	struct ext4_dir_entry_2 *de, *top;
 	struct buffer_head *bh;
-	unsigned long block;
+	ext4_lblk_t block;
 	int retval;
 	int namelen = dentry->d_name.len;
 	const u8 *name = dentry->d_name.name;
@@ -1128,7 +1130,7 @@ dx_move_dirents(char *from, char *to, struct dx_map_entry *map, int count)
 		rec_len = EXT4_DIR_REC_LEN(de->name_len);
 		memcpy (to, de, rec_len);
 		((struct ext4_dir_entry_2 *) to)->rec_len =
-				cpu_to_le16(rec_len);
+				ext4_rec_len_to_disk(rec_len);
 		de->inode = 0;
 		map++;
 		to += rec_len;
@@ -1147,13 +1149,12 @@ static struct ext4_dir_entry_2* dx_pack_dirents(char *base, int size)
 
 	prev = to = de;
 	while ((char*)de < base + size) {
-		next = (struct ext4_dir_entry_2 *) ((char *) de +
-						    le16_to_cpu(de->rec_len));
+		next = ext4_next_entry(de);
 		if (de->inode && de->name_len) {
 			rec_len = EXT4_DIR_REC_LEN(de->name_len);
 			if (de > to)
 				memmove(to, de, rec_len);
-			to->rec_len = cpu_to_le16(rec_len);
+			to->rec_len = ext4_rec_len_to_disk(rec_len);
 			prev = to;
 			to = (struct ext4_dir_entry_2 *) (((char *) to) + rec_len);
 		}
@@ -1174,7 +1175,7 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	unsigned blocksize = dir->i_sb->s_blocksize;
 	unsigned count, continued;
 	struct buffer_head *bh2;
-	u32 newblock;
+	ext4_lblk_t newblock;
 	u32 hash2;
 	struct dx_map_entry *map;
 	char *data1 = (*bh)->b_data, *data2;
@@ -1221,14 +1222,15 @@ static struct ext4_dir_entry_2 *do_split(handle_t *handle, struct inode *dir,
 	split = count - move;
 	hash2 = map[split].hash;
 	continued = hash2 == map[split - 1].hash;
-	dxtrace(printk("Split block %i at %x, %i/%i\n",
-		dx_get_block(frame->at), hash2, split, count-split));
+	dxtrace(printk(KERN_INFO "Split block %lu at %x, %i/%i\n",
+			(unsigned long)dx_get_block(frame->at),
+					hash2, split, count-split));
 
 	/* Fancy dance to stay within two buffers */
 	de2 = dx_move_dirents(data1, data2, map + split, count - split);
 	de = dx_pack_dirents(data1,blocksize);
-	de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
-	de2->rec_len = cpu_to_le16(data2 + blocksize - (char *) de2);
+	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
+	de2->rec_len = ext4_rec_len_to_disk(data2 + blocksize - (char *) de2);
 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data1, blocksize, 1));
 	dxtrace(dx_show_leaf (hinfo, (struct ext4_dir_entry_2 *) data2, blocksize, 1));
 
@@ -1297,7 +1299,7 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 				return -EEXIST;
 			}
 			nlen = EXT4_DIR_REC_LEN(de->name_len);
-			rlen = le16_to_cpu(de->rec_len);
+			rlen = ext4_rec_len_from_disk(de->rec_len);
 			if ((de->inode? rlen - nlen: rlen) >= reclen)
 				break;
 			de = (struct ext4_dir_entry_2 *)((char *)de + rlen);
@@ -1316,11 +1318,11 @@ static int add_dirent_to_buf(handle_t *handle, struct dentry *dentry,
 
 	/* By now the buffer is marked for journaling */
 	nlen = EXT4_DIR_REC_LEN(de->name_len);
-	rlen = le16_to_cpu(de->rec_len);
+	rlen = ext4_rec_len_from_disk(de->rec_len);
 	if (de->inode) {
 		struct ext4_dir_entry_2 *de1 = (struct ext4_dir_entry_2 *)((char *)de + nlen);
-		de1->rec_len = cpu_to_le16(rlen - nlen);
-		de->rec_len = cpu_to_le16(nlen);
+		de1->rec_len = ext4_rec_len_to_disk(rlen - nlen);
+		de->rec_len = ext4_rec_len_to_disk(nlen);
 		de = de1;
 	}
 	de->file_type = EXT4_FT_UNKNOWN;
@@ -1374,7 +1376,7 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 	int		retval;
 	unsigned	blocksize;
 	struct dx_hash_info hinfo;
-	u32		block;
+	ext4_lblk_t  block;
 	struct fake_dirent *fde;
 
 	blocksize =  dir->i_sb->s_blocksize;
@@ -1397,17 +1399,18 @@ static int make_indexed_dir(handle_t *handle, struct dentry *dentry,
 
 	/* The 0th block becomes the root, move the dirents out */
 	fde = &root->dotdot;
-	de = (struct ext4_dir_entry_2 *)((char *)fde + le16_to_cpu(fde->rec_len));
+	de = (struct ext4_dir_entry_2 *)((char *)fde +
+		ext4_rec_len_from_disk(fde->rec_len));
 	len = ((char *) root) + blocksize - (char *) de;
 	memcpy (data1, de, len);
 	de = (struct ext4_dir_entry_2 *) data1;
 	top = data1 + len;
-	while ((char *)(de2=(void*)de+le16_to_cpu(de->rec_len)) < top)
+	while ((char *)(de2 = ext4_next_entry(de)) < top)
 		de = de2;
-	de->rec_len = cpu_to_le16(data1 + blocksize - (char *) de);
+	de->rec_len = ext4_rec_len_to_disk(data1 + blocksize - (char *) de);
 	/* Initialize the root; the dot dirents already exist */
 	de = (struct ext4_dir_entry_2 *) (&root->dotdot);
-	de->rec_len = cpu_to_le16(blocksize - EXT4_DIR_REC_LEN(2));
+	de->rec_len = ext4_rec_len_to_disk(blocksize - EXT4_DIR_REC_LEN(2));
 	memset (&root->info, 0, sizeof(root->info));
 	root->info.info_length = sizeof(root->info);
 	root->info.hash_version = EXT4_SB(dir->i_sb)->s_def_hash_version;
@@ -1454,7 +1457,7 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 	int	retval;
 	int	dx_fallback=0;
 	unsigned blocksize;
-	u32 block, blocks;
+	ext4_lblk_t block, blocks;
 
 	sb = dir->i_sb;
 	blocksize = sb->s_blocksize;
@@ -1487,7 +1490,7 @@ static int ext4_add_entry (handle_t *handle, struct dentry *dentry,
 		return retval;
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
 	de->inode = 0;
-	de->rec_len = cpu_to_le16(blocksize);
+	de->rec_len = ext4_rec_len_to_disk(blocksize);
 	return add_dirent_to_buf(handle, dentry, inode, de, bh);
 }
 
@@ -1531,7 +1534,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 		       dx_get_count(entries), dx_get_limit(entries)));
 	/* Need to split index? */
 	if (dx_get_count(entries) == dx_get_limit(entries)) {
-		u32 newblock;
+		ext4_lblk_t newblock;
 		unsigned icount = dx_get_count(entries);
 		int levels = frame - frames;
 		struct dx_entry *entries2;
@@ -1550,7 +1553,7 @@ static int ext4_dx_add_entry(handle_t *handle, struct dentry *dentry,
 			goto cleanup;
 		node2 = (struct dx_node *)(bh2->b_data);
 		entries2 = node2->entries;
-		node2->fake.rec_len = cpu_to_le16(sb->s_blocksize);
+		node2->fake.rec_len = ext4_rec_len_to_disk(sb->s_blocksize);
 		node2->fake.inode = 0;
 		BUFFER_TRACE(frame->bh, "get_write_access");
 		err = ext4_journal_get_write_access(handle, frame->bh);
@@ -1648,9 +1651,9 @@ static int ext4_delete_entry (handle_t *handle,
 			BUFFER_TRACE(bh, "get_write_access");
 			ext4_journal_get_write_access(handle, bh);
 			if (pde)
-				pde->rec_len =
-					cpu_to_le16(le16_to_cpu(pde->rec_len) +
-						    le16_to_cpu(de->rec_len));
+				pde->rec_len = ext4_rec_len_to_disk(
+					ext4_rec_len_from_disk(pde->rec_len) +
+					ext4_rec_len_from_disk(de->rec_len));
 			else
 				de->inode = 0;
 			dir->i_version++;
@@ -1658,10 +1661,9 @@ static int ext4_delete_entry (handle_t *handle,
 			ext4_journal_dirty_metadata(handle, bh);
 			return 0;
 		}
-		i += le16_to_cpu(de->rec_len);
+		i += ext4_rec_len_from_disk(de->rec_len);
 		pde = de;
-		de = (struct ext4_dir_entry_2 *)
-			((char *) de + le16_to_cpu(de->rec_len));
+		de = ext4_next_entry(de);
 	}
 	return -ENOENT;
 }
@@ -1824,13 +1826,13 @@ retry:
 	de = (struct ext4_dir_entry_2 *) dir_block->b_data;
 	de->inode = cpu_to_le32(inode->i_ino);
 	de->name_len = 1;
-	de->rec_len = cpu_to_le16(EXT4_DIR_REC_LEN(de->name_len));
+	de->rec_len = ext4_rec_len_to_disk(EXT4_DIR_REC_LEN(de->name_len));
 	strcpy (de->name, ".");
 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
-	de = (struct ext4_dir_entry_2 *)
-			((char *) de + le16_to_cpu(de->rec_len));
+	de = ext4_next_entry(de);
 	de->inode = cpu_to_le32(dir->i_ino);
-	de->rec_len = cpu_to_le16(inode->i_sb->s_blocksize-EXT4_DIR_REC_LEN(1));
+	de->rec_len = ext4_rec_len_to_disk(inode->i_sb->s_blocksize -
+						EXT4_DIR_REC_LEN(1));
 	de->name_len = 2;
 	strcpy (de->name, "..");
 	ext4_set_de_type(dir->i_sb, de, S_IFDIR);
@@ -1882,8 +1884,7 @@ static int empty_dir (struct inode * inode)
 		return 1;
 	}
 	de = (struct ext4_dir_entry_2 *) bh->b_data;
-	de1 = (struct ext4_dir_entry_2 *)
-			((char *) de + le16_to_cpu(de->rec_len));
+	de1 = ext4_next_entry(de);
 	if (le32_to_cpu(de->inode) != inode->i_ino ||
 			!le32_to_cpu(de1->inode) ||
 			strcmp (".", de->name) ||
@@ -1894,9 +1895,9 @@ static int empty_dir (struct inode * inode)
 		brelse (bh);
 		return 1;
 	}
-	offset = le16_to_cpu(de->rec_len) + le16_to_cpu(de1->rec_len);
-	de = (struct ext4_dir_entry_2 *)
-			((char *) de1 + le16_to_cpu(de1->rec_len));
+	offset = ext4_rec_len_from_disk(de->rec_len) +
+		 ext4_rec_len_from_disk(de1->rec_len);
+	de = ext4_next_entry(de1);
 	while (offset < inode->i_size ) {
 		if (!bh ||
 			(void *) de >= (void *) (bh->b_data+sb->s_blocksize)) {
@@ -1925,9 +1926,8 @@ static int empty_dir (struct inode * inode)
 			brelse (bh);
 			return 0;
 		}
-		offset += le16_to_cpu(de->rec_len);
-		de = (struct ext4_dir_entry_2 *)
-				((char *) de + le16_to_cpu(de->rec_len));
+		offset += ext4_rec_len_from_disk(de->rec_len);
+		de = ext4_next_entry(de);
 	}
 	brelse (bh);
 	return 1;
@@ -2282,8 +2282,7 @@ retry:
 }
 
 #define PARENT_INO(buffer) \
-	((struct ext4_dir_entry_2 *) ((char *) buffer + \
-	le16_to_cpu(((struct ext4_dir_entry_2 *) buffer)->rec_len)))->inode
+	(ext4_next_entry((struct ext4_dir_entry_2 *)(buffer))->inode)
 
 /*
  * Anybody can rename anything with this: the permission checks are left to the
diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
index bd8a52bb3999..4fbba60816f4 100644
--- a/fs/ext4/resize.c
+++ b/fs/ext4/resize.c
@@ -28,7 +28,7 @@ static int verify_group_input(struct super_block *sb,
 	struct ext4_super_block *es = sbi->s_es;
 	ext4_fsblk_t start = ext4_blocks_count(es);
 	ext4_fsblk_t end = start + input->blocks_count;
-	unsigned group = input->group;
+	ext4_group_t group = input->group;
 	ext4_fsblk_t itend = input->inode_table + sbi->s_itb_per_group;
 	unsigned overhead = ext4_bg_has_super(sb, group) ?
 		(1 + ext4_bg_num_gdb(sb, group) +
@@ -206,7 +206,7 @@ static int setup_new_group_blocks(struct super_block *sb,
 	}
 
 	if (ext4_bg_has_super(sb, input->group)) {
-		ext4_debug("mark backup superblock %#04lx (+0)\n", start);
+		ext4_debug("mark backup superblock %#04llx (+0)\n", start);
 		ext4_set_bit(0, bh->b_data);
 	}
 
@@ -215,7 +215,7 @@ static int setup_new_group_blocks(struct super_block *sb,
 	     i < gdblocks; i++, block++, bit++) {
 		struct buffer_head *gdb;
 
-		ext4_debug("update backup group %#04lx (+%d)\n", block, bit);
+		ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
 
 		if ((err = extend_or_restart_transaction(handle, 1, bh)))
 			goto exit_bh;
@@ -243,7 +243,7 @@ static int setup_new_group_blocks(struct super_block *sb,
 	     i < reserved_gdb; i++, block++, bit++) {
 		struct buffer_head *gdb;
 
-		ext4_debug("clear reserved block %#04lx (+%d)\n", block, bit);
+		ext4_debug("clear reserved block %#04llx (+%d)\n", block, bit);
 
 		if ((err = extend_or_restart_transaction(handle, 1, bh)))
 			goto exit_bh;
@@ -256,10 +256,10 @@ static int setup_new_group_blocks(struct super_block *sb,
 		ext4_set_bit(bit, bh->b_data);
 		brelse(gdb);
 	}
-	ext4_debug("mark block bitmap %#04x (+%ld)\n", input->block_bitmap,
+	ext4_debug("mark block bitmap %#04llx (+%llu)\n", input->block_bitmap,
 		   input->block_bitmap - start);
 	ext4_set_bit(input->block_bitmap - start, bh->b_data);
-	ext4_debug("mark inode bitmap %#04x (+%ld)\n", input->inode_bitmap,
+	ext4_debug("mark inode bitmap %#04llx (+%llu)\n", input->inode_bitmap,
 		   input->inode_bitmap - start);
 	ext4_set_bit(input->inode_bitmap - start, bh->b_data);
 
@@ -268,7 +268,7 @@ static int setup_new_group_blocks(struct super_block *sb,
 	     i < sbi->s_itb_per_group; i++, bit++, block++) {
 		struct buffer_head *it;
 
-		ext4_debug("clear inode block %#04lx (+%d)\n", block, bit);
+		ext4_debug("clear inode block %#04llx (+%d)\n", block, bit);
 
 		if ((err = extend_or_restart_transaction(handle, 1, bh)))
 			goto exit_bh;
@@ -291,7 +291,7 @@ static int setup_new_group_blocks(struct super_block *sb,
 	brelse(bh);
 
 	/* Mark unused entries in inode bitmap used */
-	ext4_debug("clear inode bitmap %#04x (+%ld)\n",
+	ext4_debug("clear inode bitmap %#04llx (+%llu)\n",
 		   input->inode_bitmap, input->inode_bitmap - start);
 	if (IS_ERR(bh = bclean(handle, sb, input->inode_bitmap))) {
 		err = PTR_ERR(bh);
@@ -357,7 +357,7 @@ static int verify_reserved_gdb(struct super_block *sb,
 			       struct buffer_head *primary)
 {
 	const ext4_fsblk_t blk = primary->b_blocknr;
-	const unsigned long end = EXT4_SB(sb)->s_groups_count;
+	const ext4_group_t end = EXT4_SB(sb)->s_groups_count;
 	unsigned three = 1;
 	unsigned five = 5;
 	unsigned seven = 7;
@@ -656,12 +656,12 @@ static void update_backups(struct super_block *sb,
 			   int blk_off, char *data, int size)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	const unsigned long last = sbi->s_groups_count;
+	const ext4_group_t last = sbi->s_groups_count;
 	const int bpg = EXT4_BLOCKS_PER_GROUP(sb);
 	unsigned three = 1;
 	unsigned five = 5;
 	unsigned seven = 7;
-	unsigned group;
+	ext4_group_t group;
 	int rest = sb->s_blocksize - size;
 	handle_t *handle;
 	int err = 0, err2;
@@ -716,7 +716,7 @@ static void update_backups(struct super_block *sb,
 exit_err:
 	if (err) {
 		ext4_warning(sb, __FUNCTION__,
-			     "can't update backup for group %d (err %d), "
+			     "can't update backup for group %lu (err %d), "
 			     "forcing fsck on next reboot", group, err);
 		sbi->s_mount_state &= ~EXT4_VALID_FS;
 		sbi->s_es->s_state &= cpu_to_le16(~EXT4_VALID_FS);
@@ -952,7 +952,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
 		      ext4_fsblk_t n_blocks_count)
 {
 	ext4_fsblk_t o_blocks_count;
-	unsigned long o_groups_count;
+	ext4_group_t o_groups_count;
 	ext4_grpblk_t last;
 	ext4_grpblk_t add;
 	struct buffer_head * bh;
@@ -1054,7 +1054,7 @@ int ext4_group_extend(struct super_block *sb, struct ext4_super_block *es,
 	ext4_journal_dirty_metadata(handle, EXT4_SB(sb)->s_sbh);
 	sb->s_dirt = 1;
 	unlock_super(sb);
-	ext4_debug("freeing blocks %lu through %llu\n", o_blocks_count,
+	ext4_debug("freeing blocks %llu through %llu\n", o_blocks_count,
 		   o_blocks_count + add);
 	ext4_free_blocks_sb(handle, sb, o_blocks_count, add, &freed_blocks);
 	ext4_debug("freed blocks %llu through %llu\n", o_blocks_count,
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1ca0f546c466..055a0cd0168e 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -373,6 +373,66 @@ void ext4_update_dynamic_rev(struct super_block *sb)
 	 */
 }
 
+int ext4_update_compat_feature(handle_t *handle,
+					struct super_block *sb, __u32 compat)
+{
+	int err = 0;
+	if (!EXT4_HAS_COMPAT_FEATURE(sb, compat)) {
+		err = ext4_journal_get_write_access(handle,
+				EXT4_SB(sb)->s_sbh);
+		if (err)
+			return err;
+		EXT4_SET_COMPAT_FEATURE(sb, compat);
+		sb->s_dirt = 1;
+		handle->h_sync = 1;
+		BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
+					"call ext4_journal_dirty_met adata");
+		err = ext4_journal_dirty_metadata(handle,
+				EXT4_SB(sb)->s_sbh);
+	}
+	return err;
+}
+
+int ext4_update_rocompat_feature(handle_t *handle,
+					struct super_block *sb, __u32 rocompat)
+{
+	int err = 0;
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, rocompat)) {
+		err = ext4_journal_get_write_access(handle,
+				EXT4_SB(sb)->s_sbh);
+		if (err)
+			return err;
+		EXT4_SET_RO_COMPAT_FEATURE(sb, rocompat);
+		sb->s_dirt = 1;
+		handle->h_sync = 1;
+		BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
+					"call ext4_journal_dirty_met adata");
+		err = ext4_journal_dirty_metadata(handle,
+				EXT4_SB(sb)->s_sbh);
+	}
+	return err;
+}
+
+int ext4_update_incompat_feature(handle_t *handle,
+					struct super_block *sb, __u32 incompat)
+{
+	int err = 0;
+	if (!EXT4_HAS_INCOMPAT_FEATURE(sb, incompat)) {
+		err = ext4_journal_get_write_access(handle,
+				EXT4_SB(sb)->s_sbh);
+		if (err)
+			return err;
+		EXT4_SET_INCOMPAT_FEATURE(sb, incompat);
+		sb->s_dirt = 1;
+		handle->h_sync = 1;
+		BUFFER_TRACE(EXT4_SB(sb)->s_sbh,
+					"call ext4_journal_dirty_met adata");
+		err = ext4_journal_dirty_metadata(handle,
+				EXT4_SB(sb)->s_sbh);
+	}
+	return err;
+}
+
 /*
  * Open the external journal device
  */
@@ -443,6 +503,7 @@ static void ext4_put_super (struct super_block * sb)
 	struct ext4_super_block *es = sbi->s_es;
 	int i;
 
+	ext4_mb_release(sb);
 	ext4_ext_release(sb);
 	ext4_xattr_put_super(sb);
 	jbd2_journal_destroy(sbi->s_journal);
@@ -509,6 +570,8 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_block_alloc_info = NULL;
 	ei->vfs_inode.i_version = 1;
 	memset(&ei->i_cached_extent, 0, sizeof(struct ext4_ext_cache));
+	INIT_LIST_HEAD(&ei->i_prealloc_list);
+	spin_lock_init(&ei->i_prealloc_lock);
 	return &ei->vfs_inode;
 }
 
@@ -533,7 +596,7 @@ static void init_once(struct kmem_cache *cachep, void *foo)
 #ifdef CONFIG_EXT4DEV_FS_XATTR
 	init_rwsem(&ei->xattr_sem);
 #endif
-	mutex_init(&ei->truncate_mutex);
+	init_rwsem(&ei->i_data_sem);
 	inode_init_once(&ei->vfs_inode);
 }
 
@@ -605,18 +668,20 @@ static inline void ext4_show_quota_options(struct seq_file *seq, struct super_bl
  */
 static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 {
+	int def_errors;
+	unsigned long def_mount_opts;
 	struct super_block *sb = vfs->mnt_sb;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	struct ext4_super_block *es = sbi->s_es;
-	unsigned long def_mount_opts;
 
 	def_mount_opts = le32_to_cpu(es->s_default_mount_opts);
+	def_errors     = le16_to_cpu(es->s_errors);
 
 	if (sbi->s_sb_block != 1)
 		seq_printf(seq, ",sb=%llu", sbi->s_sb_block);
 	if (test_opt(sb, MINIX_DF))
 		seq_puts(seq, ",minixdf");
-	if (test_opt(sb, GRPID))
+	if (test_opt(sb, GRPID) && !(def_mount_opts & EXT4_DEFM_BSDGROUPS))
 		seq_puts(seq, ",grpid");
 	if (!test_opt(sb, GRPID) && (def_mount_opts & EXT4_DEFM_BSDGROUPS))
 		seq_puts(seq, ",nogrpid");
@@ -628,34 +693,33 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 	    le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID) {
 		seq_printf(seq, ",resgid=%u", sbi->s_resgid);
 	}
-	if (test_opt(sb, ERRORS_CONT)) {
-		int def_errors = le16_to_cpu(es->s_errors);
-
+	if (test_opt(sb, ERRORS_RO)) {
 		if (def_errors == EXT4_ERRORS_PANIC ||
-		    def_errors == EXT4_ERRORS_RO) {
-			seq_puts(seq, ",errors=continue");
+		    def_errors == EXT4_ERRORS_CONTINUE) {
+			seq_puts(seq, ",errors=remount-ro");
 		}
 	}
-	if (test_opt(sb, ERRORS_RO))
-		seq_puts(seq, ",errors=remount-ro");
-	if (test_opt(sb, ERRORS_PANIC))
+	if (test_opt(sb, ERRORS_CONT) && def_errors != EXT4_ERRORS_CONTINUE)
+		seq_puts(seq, ",errors=continue");
+	if (test_opt(sb, ERRORS_PANIC) && def_errors != EXT4_ERRORS_PANIC)
 		seq_puts(seq, ",errors=panic");
-	if (test_opt(sb, NO_UID32))
+	if (test_opt(sb, NO_UID32) && !(def_mount_opts & EXT4_DEFM_UID16))
 		seq_puts(seq, ",nouid32");
-	if (test_opt(sb, DEBUG))
+	if (test_opt(sb, DEBUG) && !(def_mount_opts & EXT4_DEFM_DEBUG))
 		seq_puts(seq, ",debug");
 	if (test_opt(sb, OLDALLOC))
 		seq_puts(seq, ",oldalloc");
-#ifdef CONFIG_EXT4_FS_XATTR
-	if (test_opt(sb, XATTR_USER))
+#ifdef CONFIG_EXT4DEV_FS_XATTR
+	if (test_opt(sb, XATTR_USER) &&
+		!(def_mount_opts & EXT4_DEFM_XATTR_USER))
 		seq_puts(seq, ",user_xattr");
 	if (!test_opt(sb, XATTR_USER) &&
 	    (def_mount_opts & EXT4_DEFM_XATTR_USER)) {
 		seq_puts(seq, ",nouser_xattr");
 	}
 #endif
-#ifdef CONFIG_EXT4_FS_POSIX_ACL
-	if (test_opt(sb, POSIX_ACL))
+#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL
+	if (test_opt(sb, POSIX_ACL) && !(def_mount_opts & EXT4_DEFM_ACL))
 		seq_puts(seq, ",acl");
 	if (!test_opt(sb, POSIX_ACL) && (def_mount_opts & EXT4_DEFM_ACL))
 		seq_puts(seq, ",noacl");
@@ -672,7 +736,17 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",nobh");
 	if (!test_opt(sb, EXTENTS))
 		seq_puts(seq, ",noextents");
+	if (!test_opt(sb, MBALLOC))
+		seq_puts(seq, ",nomballoc");
+	if (test_opt(sb, I_VERSION))
+		seq_puts(seq, ",i_version");
 
+	if (sbi->s_stripe)
+		seq_printf(seq, ",stripe=%lu", sbi->s_stripe);
+	/*
+	 * journal mode get enabled in different ways
+	 * So just print the value even if we didn't specify it
+	 */
 	if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_JOURNAL_DATA)
 		seq_puts(seq, ",data=journal");
 	else if (test_opt(sb, DATA_FLAGS) == EXT4_MOUNT_ORDERED_DATA)
@@ -681,7 +755,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs)
 		seq_puts(seq, ",data=writeback");
 
 	ext4_show_quota_options(seq, sb);
-
 	return 0;
 }
 
@@ -809,11 +882,13 @@ enum {
 	Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl,
 	Opt_reservation, Opt_noreservation, Opt_noload, Opt_nobh, Opt_bh,
 	Opt_commit, Opt_journal_update, Opt_journal_inum, Opt_journal_dev,
+	Opt_journal_checksum, Opt_journal_async_commit,
 	Opt_abort, Opt_data_journal, Opt_data_ordered, Opt_data_writeback,
 	Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota,
 	Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota,
 	Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota,
-	Opt_grpquota, Opt_extents, Opt_noextents,
+	Opt_grpquota, Opt_extents, Opt_noextents, Opt_i_version,
+	Opt_mballoc, Opt_nomballoc, Opt_stripe,
 };
 
 static match_table_t tokens = {
@@ -848,6 +923,8 @@ static match_table_t tokens = {
 	{Opt_journal_update, "journal=update"},
 	{Opt_journal_inum, "journal=%u"},
 	{Opt_journal_dev, "journal_dev=%u"},
+	{Opt_journal_checksum, "journal_checksum"},
+	{Opt_journal_async_commit, "journal_async_commit"},
 	{Opt_abort, "abort"},
 	{Opt_data_journal, "data=journal"},
 	{Opt_data_ordered, "data=ordered"},
@@ -865,6 +942,10 @@ static match_table_t tokens = {
 	{Opt_barrier, "barrier=%u"},
 	{Opt_extents, "extents"},
 	{Opt_noextents, "noextents"},
+	{Opt_i_version, "i_version"},
+	{Opt_mballoc, "mballoc"},
+	{Opt_nomballoc, "nomballoc"},
+	{Opt_stripe, "stripe=%u"},
 	{Opt_err, NULL},
 	{Opt_resize, "resize"},
 };
@@ -1035,6 +1116,13 @@ static int parse_options (char *options, struct super_block *sb,
 				return 0;
 			*journal_devnum = option;
 			break;
+		case Opt_journal_checksum:
+			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
+			break;
+		case Opt_journal_async_commit:
+			set_opt(sbi->s_mount_opt, JOURNAL_ASYNC_COMMIT);
+			set_opt(sbi->s_mount_opt, JOURNAL_CHECKSUM);
+			break;
 		case Opt_noload:
 			set_opt (sbi->s_mount_opt, NOLOAD);
 			break;
@@ -1203,6 +1291,23 @@ clear_qf_name:
 		case Opt_noextents:
 			clear_opt (sbi->s_mount_opt, EXTENTS);
 			break;
+		case Opt_i_version:
+			set_opt(sbi->s_mount_opt, I_VERSION);
+			sb->s_flags |= MS_I_VERSION;
+			break;
+		case Opt_mballoc:
+			set_opt(sbi->s_mount_opt, MBALLOC);
+			break;
+		case Opt_nomballoc:
+			clear_opt(sbi->s_mount_opt, MBALLOC);
+			break;
+		case Opt_stripe:
+			if (match_int(&args[0], &option))
+				return 0;
+			if (option < 0)
+				return 0;
+			sbi->s_stripe = option;
+			break;
 		default:
 			printk (KERN_ERR
 				"EXT4-fs: Unrecognized mount option \"%s\" "
@@ -1364,7 +1469,7 @@ static int ext4_check_descriptors (struct super_block * sb)
 	struct ext4_group_desc * gdp = NULL;
 	int desc_block = 0;
 	int flexbg_flag = 0;
-	int i;
+	ext4_group_t i;
 
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG))
 		flexbg_flag = 1;
@@ -1386,7 +1491,7 @@ static int ext4_check_descriptors (struct super_block * sb)
 		if (block_bitmap < first_block || block_bitmap > last_block)
 		{
 			ext4_error (sb, "ext4_check_descriptors",
-				    "Block bitmap for group %d"
+				    "Block bitmap for group %lu"
 				    " not in group (block %llu)!",
 				    i, block_bitmap);
 			return 0;
@@ -1395,7 +1500,7 @@ static int ext4_check_descriptors (struct super_block * sb)
 		if (inode_bitmap < first_block || inode_bitmap > last_block)
 		{
 			ext4_error (sb, "ext4_check_descriptors",
-				    "Inode bitmap for group %d"
+				    "Inode bitmap for group %lu"
 				    " not in group (block %llu)!",
 				    i, inode_bitmap);
 			return 0;
@@ -1405,17 +1510,16 @@ static int ext4_check_descriptors (struct super_block * sb)
 		    inode_table + sbi->s_itb_per_group - 1 > last_block)
 		{
 			ext4_error (sb, "ext4_check_descriptors",
-				    "Inode table for group %d"
+				    "Inode table for group %lu"
 				    " not in group (block %llu)!",
 				    i, inode_table);
 			return 0;
 		}
 		if (!ext4_group_desc_csum_verify(sbi, i, gdp)) {
 			ext4_error(sb, __FUNCTION__,
-				   "Checksum for group %d failed (%u!=%u)\n", i,
-				   le16_to_cpu(ext4_group_desc_csum(sbi, i,
-								    gdp)),
-				   le16_to_cpu(gdp->bg_checksum));
+				   "Checksum for group %lu failed (%u!=%u)\n",
+				    i, le16_to_cpu(ext4_group_desc_csum(sbi, i,
+				    gdp)), le16_to_cpu(gdp->bg_checksum));
 			return 0;
 		}
 		if (!flexbg_flag)
@@ -1429,7 +1533,6 @@ static int ext4_check_descriptors (struct super_block * sb)
 	return 1;
 }
 
-
 /* ext4_orphan_cleanup() walks a singly-linked list of inodes (starting at
  * the superblock) which were deleted from all directories, but held open by
  * a process at the time of a crash.  We walk the list and try to delete these
@@ -1542,20 +1645,95 @@ static void ext4_orphan_cleanup (struct super_block * sb,
 #endif
 	sb->s_flags = s_flags; /* Restore MS_RDONLY status */
 }
+/*
+ * Maximal extent format file size.
+ * Resulting logical blkno at s_maxbytes must fit in our on-disk
+ * extent format containers, within a sector_t, and within i_blocks
+ * in the vfs.  ext4 inode has 48 bits of i_block in fsblock units,
+ * so that won't be a limiting factor.
+ *
+ * Note, this does *not* consider any metadata overhead for vfs i_blocks.
+ */
+static loff_t ext4_max_size(int blkbits)
+{
+	loff_t res;
+	loff_t upper_limit = MAX_LFS_FILESIZE;
+
+	/* small i_blocks in vfs inode? */
+	if (sizeof(blkcnt_t) < sizeof(u64)) {
+		/*
+		 * CONFIG_LSF is not enabled implies the inode
+		 * i_block represent total blocks in 512 bytes
+		 * 32 == size of vfs inode i_blocks * 8
+		 */
+		upper_limit = (1LL << 32) - 1;
+
+		/* total blocks in file system block size */
+		upper_limit >>= (blkbits - 9);
+		upper_limit <<= blkbits;
+	}
+
+	/* 32-bit extent-start container, ee_block */
+	res = 1LL << 32;
+	res <<= blkbits;
+	res -= 1;
+
+	/* Sanity check against vm- & vfs- imposed limits */
+	if (res > upper_limit)
+		res = upper_limit;
+
+	return res;
+}
 
 /*
- * Maximal file size.  There is a direct, and {,double-,triple-}indirect
- * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks.
- * We need to be 1 filesystem block less than the 2^32 sector limit.
+ * Maximal bitmap file size.  There is a direct, and {,double-,triple-}indirect
+ * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks.
+ * We need to be 1 filesystem block less than the 2^48 sector limit.
  */
-static loff_t ext4_max_size(int bits)
+static loff_t ext4_max_bitmap_size(int bits)
 {
 	loff_t res = EXT4_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, bitmapped 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 2^48 -1
+	 * __u32 i_blocks_lo and _u16 i_blocks_high representing the
+	 * total number of  512 bytes blocks of the file
+	 */
+
+	if (sizeof(blkcnt_t) < sizeof(u64)) {
+		/*
+		 * CONFIG_LSF is not enabled implies the inode
+		 * i_block represent total blocks in 512 bytes
+		 * 32 == size of vfs inode i_blocks * 8
+		 */
+		upper_limit = (1LL << 32) - 1;
+
+		/* total blocks in file system block size */
+		upper_limit >>= (bits - 9);
+
+	} else {
+		/*
+		 * We use 48 bit ext4_inode i_blocks
+		 * With EXT4_HUGE_FILE_FL set the i_blocks
+		 * represent total number of blocks in
+		 * file system block size
+		 */
+		upper_limit = (1LL << 48) - 1;
+
+	}
+
+	/* 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));
@@ -1563,6 +1741,10 @@ static loff_t ext4_max_size(int bits)
 	res <<= bits;
 	if (res > upper_limit)
 		res = upper_limit;
+
+	if (res > MAX_LFS_FILESIZE)
+		res = MAX_LFS_FILESIZE;
+
 	return res;
 }
 
@@ -1570,7 +1752,7 @@ static ext4_fsblk_t descriptor_loc(struct super_block *sb,
 				ext4_fsblk_t logical_sb_block, int nr)
 {
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
-	unsigned long bg, first_meta_bg;
+	ext4_group_t bg, first_meta_bg;
 	int has_super = 0;
 
 	first_meta_bg = le32_to_cpu(sbi->s_es->s_first_meta_bg);
@@ -1584,8 +1766,39 @@ static ext4_fsblk_t descriptor_loc(struct super_block *sb,
 	return (has_super + ext4_group_first_block_no(sb, bg));
 }
 
+/**
+ * ext4_get_stripe_size: Get the stripe size.
+ * @sbi: In memory super block info
+ *
+ * If we have specified it via mount option, then
+ * use the mount option value. If the value specified at mount time is
+ * greater than the blocks per group use the super block value.
+ * If the super block value is greater than blocks per group return 0.
+ * Allocator needs it be less than blocks per group.
+ *
+ */
+static unsigned long ext4_get_stripe_size(struct ext4_sb_info *sbi)
+{
+	unsigned long stride = le16_to_cpu(sbi->s_es->s_raid_stride);
+	unsigned long stripe_width =
+			le32_to_cpu(sbi->s_es->s_raid_stripe_width);
+
+	if (sbi->s_stripe && sbi->s_stripe <= sbi->s_blocks_per_group)
+		return sbi->s_stripe;
+
+	if (stripe_width <= sbi->s_blocks_per_group)
+		return stripe_width;
+
+	if (stride <= sbi->s_blocks_per_group)
+		return stride;
+
+	return 0;
+}
 
 static int ext4_fill_super (struct super_block *sb, void *data, int silent)
+				__releases(kernel_sem)
+				__acquires(kernel_sem)
+
 {
 	struct buffer_head * bh;
 	struct ext4_super_block *es = NULL;
@@ -1599,7 +1812,6 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	unsigned long def_mount_opts;
 	struct inode *root;
 	int blocksize;
-	int hblock;
 	int db_count;
 	int i;
 	int needs_recovery;
@@ -1624,6 +1836,11 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto out_fail;
 	}
 
+	if (!sb_set_blocksize(sb, blocksize)) {
+		printk(KERN_ERR "EXT4-fs: bad blocksize %d.\n", blocksize);
+		goto out_fail;
+	}
+
 	/*
 	 * The ext4 superblock will not be buffer aligned for other than 1kB
 	 * block sizes.  We need to calculate the offset from buffer start.
@@ -1674,10 +1891,10 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
 	if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_PANIC)
 		set_opt(sbi->s_mount_opt, ERRORS_PANIC);
-	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_RO)
-		set_opt(sbi->s_mount_opt, ERRORS_RO);
-	else
+	else if (le16_to_cpu(sbi->s_es->s_errors) == EXT4_ERRORS_CONTINUE)
 		set_opt(sbi->s_mount_opt, ERRORS_CONT);
+	else
+		set_opt(sbi->s_mount_opt, ERRORS_RO);
 
 	sbi->s_resuid = le16_to_cpu(es->s_def_resuid);
 	sbi->s_resgid = le16_to_cpu(es->s_def_resgid);
@@ -1689,6 +1906,11 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	 * User -o noextents to turn it off
 	 */
 	set_opt(sbi->s_mount_opt, EXTENTS);
+	/*
+	 * turn on mballoc feature by default in ext4 filesystem
+	 * User -o nomballoc to turn it off
+	 */
+	set_opt(sbi->s_mount_opt, MBALLOC);
 
 	if (!parse_options ((char *) data, sb, &journal_inum, &journal_devnum,
 			    NULL, 0))
@@ -1723,6 +1945,19 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		       sb->s_id, le32_to_cpu(features));
 		goto failed_mount;
 	}
+	if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) {
+		/*
+		 * Large file size enabled file system can only be
+		 * mount if kernel is build with CONFIG_LSF
+		 */
+		if (sizeof(root->i_blocks) < sizeof(u64) &&
+				!(sb->s_flags & MS_RDONLY)) {
+			printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge "
+					"files cannot be mounted read-write "
+					"without CONFIG_LSF.\n", sb->s_id);
+			goto failed_mount;
+		}
+	}
 	blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size);
 
 	if (blocksize < EXT4_MIN_BLOCK_SIZE ||
@@ -1733,20 +1968,16 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto failed_mount;
 	}
 
-	hblock = bdev_hardsect_size(sb->s_bdev);
 	if (sb->s_blocksize != blocksize) {
-		/*
-		 * Make sure the blocksize for the filesystem is larger
-		 * than the hardware sectorsize for the machine.
-		 */
-		if (blocksize < hblock) {
-			printk(KERN_ERR "EXT4-fs: blocksize %d too small for "
-			       "device blocksize %d.\n", blocksize, hblock);
+
+		/* Validate the filesystem blocksize */
+		if (!sb_set_blocksize(sb, blocksize)) {
+			printk(KERN_ERR "EXT4-fs: bad block size %d.\n",
+					blocksize);
 			goto failed_mount;
 		}
 
 		brelse (bh);
-		sb_set_blocksize(sb, blocksize);
 		logical_sb_block = sb_block * EXT4_MIN_BLOCK_SIZE;
 		offset = do_div(logical_sb_block, blocksize);
 		bh = sb_bread(sb, logical_sb_block);
@@ -1764,6 +1995,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		}
 	}
 
+	sbi->s_bitmap_maxbytes = ext4_max_bitmap_size(sb->s_blocksize_bits);
 	sb->s_maxbytes = ext4_max_size(sb->s_blocksize_bits);
 
 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV) {
@@ -1838,6 +2070,17 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 
 	if (EXT4_BLOCKS_PER_GROUP(sb) == 0)
 		goto cantfind_ext4;
+
+	/* ensure blocks_count calculation below doesn't sign-extend */
+	if (ext4_blocks_count(es) + EXT4_BLOCKS_PER_GROUP(sb) <
+	    le32_to_cpu(es->s_first_data_block) + 1) {
+		printk(KERN_WARNING "EXT4-fs: bad geometry: block count %llu, "
+		       "first data block %u, blocks per group %lu\n",
+			ext4_blocks_count(es),
+			le32_to_cpu(es->s_first_data_block),
+			EXT4_BLOCKS_PER_GROUP(sb));
+		goto failed_mount;
+	}
 	blocks_count = (ext4_blocks_count(es) -
 			le32_to_cpu(es->s_first_data_block) +
 			EXT4_BLOCKS_PER_GROUP(sb) - 1);
@@ -1900,6 +2143,8 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 	sbi->s_rsv_window_head.rsv_goal_size = 0;
 	ext4_rsv_window_add(sb, &sbi->s_rsv_window_head);
 
+	sbi->s_stripe = ext4_get_stripe_size(sbi);
+
 	/*
 	 * set up enough so that it can read an inode
 	 */
@@ -1944,6 +2189,21 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		goto failed_mount4;
 	}
 
+	if (test_opt(sb, JOURNAL_ASYNC_COMMIT)) {
+		jbd2_journal_set_features(sbi->s_journal,
+				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	} else if (test_opt(sb, JOURNAL_CHECKSUM)) {
+		jbd2_journal_set_features(sbi->s_journal,
+				JBD2_FEATURE_COMPAT_CHECKSUM, 0, 0);
+		jbd2_journal_clear_features(sbi->s_journal, 0, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	} else {
+		jbd2_journal_clear_features(sbi->s_journal,
+				JBD2_FEATURE_COMPAT_CHECKSUM, 0,
+				JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT);
+	}
+
 	/* We have now updated the journal if required, so we can
 	 * validate the data journaling mode. */
 	switch (test_opt(sb, DATA_FLAGS)) {
@@ -2044,6 +2304,7 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		"writeback");
 
 	ext4_ext_init(sb);
+	ext4_mb_init(sb, needs_recovery);
 
 	lock_kernel();
 	return 0;
@@ -2673,7 +2934,7 @@ static int ext4_statfs (struct dentry * dentry, struct kstatfs * buf)
 	if (test_opt(sb, MINIX_DF)) {
 		sbi->s_overhead_last = 0;
 	} else if (sbi->s_blocks_last != ext4_blocks_count(es)) {
-		unsigned long ngroups = sbi->s_groups_count, i;
+		ext4_group_t ngroups = sbi->s_groups_count, i;
 		ext4_fsblk_t overhead = 0;
 		smp_rmb();
 
@@ -2909,7 +3170,7 @@ static ssize_t ext4_quota_read(struct super_block *sb, int type, char *data,
 			       size_t len, loff_t off)
 {
 	struct inode *inode = sb_dqopt(sb)->files[type];
-	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
+	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
 	int err = 0;
 	int offset = off & (sb->s_blocksize - 1);
 	int tocopy;
@@ -2947,7 +3208,7 @@ static ssize_t ext4_quota_write(struct super_block *sb, int type,
 				const char *data, size_t len, loff_t off)
 {
 	struct inode *inode = sb_dqopt(sb)->files[type];
-	sector_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
+	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
 	int err = 0;
 	int offset = off & (sb->s_blocksize - 1);
 	int tocopy;
@@ -3002,7 +3263,6 @@ out:
 		i_size_write(inode, off+len-towrite);
 		EXT4_I(inode)->i_disksize = inode->i_size;
 	}
-	inode->i_version++;
 	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
 	ext4_mark_inode_dirty(handle, inode);
 	mutex_unlock(&inode->i_mutex);
@@ -3027,9 +3287,15 @@ static struct file_system_type ext4dev_fs_type = {
 
 static int __init init_ext4_fs(void)
 {
-	int err = init_ext4_xattr();
+	int err;
+
+	err = init_ext4_mballoc();
 	if (err)
 		return err;
+
+	err = init_ext4_xattr();
+	if (err)
+		goto out2;
 	err = init_inodecache();
 	if (err)
 		goto out1;
@@ -3041,6 +3307,8 @@ out:
 	destroy_inodecache();
 out1:
 	exit_ext4_xattr();
+out2:
+	exit_ext4_mballoc();
 	return err;
 }
 
@@ -3049,6 +3317,7 @@ static void __exit exit_ext4_fs(void)
 	unregister_filesystem(&ext4dev_fs_type);
 	destroy_inodecache();
 	exit_ext4_xattr();
+	exit_ext4_mballoc();
 }
 
 MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others");
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 86387302c2a9..d7962139c010 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -480,7 +480,7 @@ ext4_xattr_release_block(handle_t *handle, struct inode *inode,
 		ea_bdebug(bh, "refcount now=0; freeing");
 		if (ce)
 			mb_cache_entry_free(ce);
-		ext4_free_blocks(handle, inode, bh->b_blocknr, 1);
+		ext4_free_blocks(handle, inode, bh->b_blocknr, 1, 1);
 		get_bh(bh);
 		ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
 	} else {
@@ -821,7 +821,7 @@ inserted:
 			new_bh = sb_getblk(sb, block);
 			if (!new_bh) {
 getblk_failed:
-				ext4_free_blocks(handle, inode, block, 1);
+				ext4_free_blocks(handle, inode, block, 1, 1);
 				error = -EIO;
 				goto cleanup;
 			}