Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: Add new "development flag" to the ext4 filesystem
  ext4: Don't panic in case of corrupt bitmap
  ext4: allocate struct ext4_allocation_context from a kmem cache
  JBD2:  Clear buffer_ordered flag for barried IO request on success
  ext4: Fix Direct I/O locking
  ext4: Fix circular locking dependency with migrate and rm.
  allow in-inode EAs on ext4 root inode
  ext4: Fix null bh pointer dereference in mballoc
  ext4: Don't set EXTENTS_FL flag for fast symlinks
  JBD2: Use the incompat macro for testing the incompat feature.
  jbd2: Fix reference counting on the journal commit block's buffer head
  [PATCH] jbd: Remove useless loop when writing commit record
  jbd2: Add error check to journal_wait_on_commit_record to avoid oops

9 files changed, 270 insertions, 177 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index f4e387452246..7dd9b50d5ebc 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -892,7 +892,16 @@ out:
 	return err;
 }
 
-#define DIO_CREDITS (EXT4_RESERVE_TRANS_BLOCKS + 32)
+/* Maximum number of blocks we map for direct IO at once. */
+#define DIO_MAX_BLOCKS 4096
+/*
+ * Number of credits we need for writing DIO_MAX_BLOCKS:
+ * We need sb + group descriptor + bitmap + inode -> 4
+ * For B blocks with A block pointers per block we need:
+ * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
+ * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
+ */
+#define DIO_CREDITS 25
 
 int ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block,
 			unsigned long max_blocks, struct buffer_head *bh,
@@ -939,49 +948,31 @@ static int ext4_get_block(struct inode *inode, sector_t iblock,
 			struct buffer_head *bh_result, int create)
 {
 	handle_t *handle = ext4_journal_current_handle();
-	int ret = 0;
+	int ret = 0, started = 0;
 	unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
 
-	if (!create)
-		goto get_block;		/* A read */
-
-	if (max_blocks == 1)
-		goto get_block;		/* A single block get */
-
-	if (handle->h_transaction->t_state == T_LOCKED) {
-		/*
-		 * Huge direct-io writes can hold off commits for long
-		 * periods of time.  Let this commit run.
-		 */
-		ext4_journal_stop(handle);
-		handle = ext4_journal_start(inode, DIO_CREDITS);
-		if (IS_ERR(handle))
+	if (create && !handle) {
+		/* Direct IO write... */
+		if (max_blocks > DIO_MAX_BLOCKS)
+			max_blocks = DIO_MAX_BLOCKS;
+		handle = ext4_journal_start(inode, DIO_CREDITS +
+			      2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb));
+		if (IS_ERR(handle)) {
 			ret = PTR_ERR(handle);
-		goto get_block;
-	}
-
-	if (handle->h_buffer_credits <= EXT4_RESERVE_TRANS_BLOCKS) {
-		/*
-		 * Getting low on buffer credits...
-		 */
-		ret = ext4_journal_extend(handle, DIO_CREDITS);
-		if (ret > 0) {
-			/*
-			 * Couldn't extend the transaction.  Start a new one.
-			 */
-			ret = ext4_journal_restart(handle, DIO_CREDITS);
+			goto out;
 		}
+		started = 1;
 	}
 
-get_block:
-	if (ret == 0) {
-		ret = ext4_get_blocks_wrap(handle, inode, iblock,
+	ret = ext4_get_blocks_wrap(handle, inode, iblock,
 					max_blocks, bh_result, create, 0);
-		if (ret > 0) {
-			bh_result->b_size = (ret << inode->i_blkbits);
-			ret = 0;
-		}
+	if (ret > 0) {
+		bh_result->b_size = (ret << inode->i_blkbits);
+		ret = 0;
 	}
+	if (started)
+		ext4_journal_stop(handle);
+out:
 	return ret;
 }
 
@@ -1671,7 +1662,8 @@ static int ext4_releasepage(struct page *page, gfp_t wait)
  * if the machine crashes during the write.
  *
  * If the O_DIRECT write is intantiating holes inside i_size and the machine
- * crashes then stale disk data _may_ be exposed inside the file.
+ * crashes then stale disk data _may_ be exposed inside the file. But current
+ * VFS code falls back into buffered path in that case so we are safe.
  */
 static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
 			const struct iovec *iov, loff_t offset,
@@ -1680,7 +1672,7 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
 	struct file *file = iocb->ki_filp;
 	struct inode *inode = file->f_mapping->host;
 	struct ext4_inode_info *ei = EXT4_I(inode);
-	handle_t *handle = NULL;
+	handle_t *handle;
 	ssize_t ret;
 	int orphan = 0;
 	size_t count = iov_length(iov, nr_segs);
@@ -1688,17 +1680,21 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
 	if (rw == WRITE) {
 		loff_t final_size = offset + count;
 
-		handle = ext4_journal_start(inode, DIO_CREDITS);
-		if (IS_ERR(handle)) {
-			ret = PTR_ERR(handle);
-			goto out;
-		}
 		if (final_size > inode->i_size) {
+			/* Credits for sb + inode write */
+			handle = ext4_journal_start(inode, 2);
+			if (IS_ERR(handle)) {
+				ret = PTR_ERR(handle);
+				goto out;
+			}
 			ret = ext4_orphan_add(handle, inode);
-			if (ret)
-				goto out_stop;
+			if (ret) {
+				ext4_journal_stop(handle);
+				goto out;
+			}
 			orphan = 1;
 			ei->i_disksize = inode->i_size;
+			ext4_journal_stop(handle);
 		}
 	}
 
@@ -1706,18 +1702,21 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb,
 				 offset, nr_segs,
 				 ext4_get_block, NULL);
 
-	/*
-	 * Reacquire the handle: ext4_get_block() can restart the transaction
-	 */
-	handle = ext4_journal_current_handle();
-
-out_stop:
-	if (handle) {
+	if (orphan) {
 		int err;
 
-		if (orphan && inode->i_nlink)
+		/* Credits for sb + inode write */
+		handle = ext4_journal_start(inode, 2);
+		if (IS_ERR(handle)) {
+			/* This is really bad luck. We've written the data
+			 * but cannot extend i_size. Bail out and pretend
+			 * the write failed... */
+			ret = PTR_ERR(handle);
+			goto out;
+		}
+		if (inode->i_nlink)
 			ext4_orphan_del(handle, inode);
-		if (orphan && ret > 0) {
+		if (ret > 0) {
 			loff_t end = offset + ret;
 			if (end > inode->i_size) {
 				ei->i_disksize = end;
@@ -2758,13 +2757,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 		ei->i_data[block] = raw_inode->i_block[block];
 	INIT_LIST_HEAD(&ei->i_orphan);
 
-	if (inode->i_ino >= EXT4_FIRST_INO(inode->i_sb) + 1 &&
-	    EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
-		/*
-		 * When mke2fs creates big inodes it does not zero out
-		 * the unused bytes above EXT4_GOOD_OLD_INODE_SIZE,
-		 * so ignore those first few inodes.
-		 */
+	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
 		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
 		if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
 		    EXT4_INODE_SIZE(inode->i_sb)) {
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 76e5fedc0a0b..dd0fcfcb35ce 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -420,6 +420,7 @@
 #define MB_DEFAULT_GROUP_PREALLOC	512
 
 static struct kmem_cache *ext4_pspace_cachep;
+static struct kmem_cache *ext4_ac_cachep;
 
 #ifdef EXT4_BB_MAX_BLOCKS
 #undef EXT4_BB_MAX_BLOCKS
@@ -680,7 +681,6 @@ 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);
 
@@ -964,7 +964,7 @@ static void ext4_mb_generate_buddy(struct super_block *sb,
 	grp->bb_fragments = fragments;
 
 	if (free != grp->bb_free) {
-		printk(KERN_DEBUG
+		ext4_error(sb, __FUNCTION__,
 			"EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
 			group, free, grp->bb_free);
 		grp->bb_free = free;
@@ -1821,13 +1821,24 @@ static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
 		i = ext4_find_next_zero_bit(bitmap,
 						EXT4_BLOCKS_PER_GROUP(sb), i);
 		if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
-			BUG_ON(free != 0);
+			/*
+			 * IF we corrupt the bitmap  we won't find any
+			 * free blocks even though group info says we
+			 * we have free blocks
+			 */
+			ext4_error(sb, __FUNCTION__, "%d free blocks as per "
+					"group info. But bitmap says 0\n",
+					free);
 			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);
+		if (free < ex.fe_len) {
+			ext4_error(sb, __FUNCTION__, "%d free blocks as per "
+					"group info. But got %d blocks\n",
+					free, ex.fe_len);
+		}
 
 		ext4_mb_measure_extent(ac, &ex, e4b);
 
@@ -2959,12 +2970,19 @@ int __init init_ext4_mballoc(void)
 	if (ext4_pspace_cachep == NULL)
 		return -ENOMEM;
 
+	ext4_ac_cachep =
+		kmem_cache_create("ext4_alloc_context",
+				     sizeof(struct ext4_allocation_context),
+				     0, SLAB_RECLAIM_ACCOUNT, NULL);
+	if (ext4_ac_cachep == NULL) {
+		kmem_cache_destroy(ext4_pspace_cachep);
+		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;
 }
 
@@ -2972,6 +2990,7 @@ void exit_ext4_mballoc(void)
 {
 	/* XXX: synchronize_rcu(); */
 	kmem_cache_destroy(ext4_pspace_cachep);
+	kmem_cache_destroy(ext4_ac_cachep);
 #ifdef CONFIG_PROC_FS
 	remove_proc_entry(EXT4_ROOT, proc_root_fs);
 #endif
@@ -3069,7 +3088,7 @@ static int ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
 
 out_err:
 	sb->s_dirt = 1;
-	put_bh(bitmap_bh);
+	brelse(bitmap_bh);
 	return err;
 }
 
@@ -3354,13 +3373,10 @@ static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
 	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
+	 * possible race when the 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 ?
+	 * in on-disk bitmap -- see ext4_mb_release_context()
+	 * Other CPUs are prevented from allocating from this pa by lg_mutex
 	 */
 	mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
 }
@@ -3699,7 +3715,7 @@ 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 ext4_allocation_context *ac;
 	struct super_block *sb = e4b->bd_sb;
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	unsigned long end;
@@ -3715,9 +3731,13 @@ static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,
 	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;
+	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
+
+	if (ac) {
+		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);
@@ -3733,24 +3753,28 @@ static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,
 				(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);
+		if (ac) {
+			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",
+		printk(KERN_CRIT "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);
+		ext4_error(sb, __FUNCTION__, "free %u, pa_free %u\n",
+						free, pa->pa_free);
 	}
-	BUG_ON(free != pa->pa_free);
 	atomic_add(free, &sbi->s_mb_discarded);
+	if (ac)
+		kmem_cache_free(ext4_ac_cachep, ac);
 
 	return err;
 }
@@ -3758,12 +3782,15 @@ static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,
 static int ext4_mb_release_group_pa(struct ext4_buddy *e4b,
 				struct ext4_prealloc_space *pa)
 {
-	struct ext4_allocation_context ac;
+	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;
+	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
+
+	if (ac)
+		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);
@@ -3771,13 +3798,16 @@ static int ext4_mb_release_group_pa(struct ext4_buddy *e4b,
 	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);
+	if (ac) {
+		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);
+		kmem_cache_free(ext4_ac_cachep, ac);
+	}
 
 	return 0;
 }
@@ -4231,7 +4261,7 @@ static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
 ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
 				 struct ext4_allocation_request *ar, int *errp)
 {
-	struct ext4_allocation_context ac;
+	struct ext4_allocation_context *ac = NULL;
 	struct ext4_sb_info *sbi;
 	struct super_block *sb;
 	ext4_fsblk_t block = 0;
@@ -4257,53 +4287,60 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
 	}
 	inquota = ar->len;
 
+	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
+	if (!ac) {
+		*errp = -ENOMEM;
+		return 0;
+	}
+
 	ext4_mb_poll_new_transaction(sb, handle);
 
-	*errp = ext4_mb_initialize_context(&ac, ar);
+	*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_PREALLOC;
+	if (!ext4_mb_use_preallocated(ac)) {
 
-		ac.ac_op = EXT4_MB_HISTORY_ALLOC;
-		ext4_mb_normalize_request(&ac, ar);
+		ac->ac_op = EXT4_MB_HISTORY_ALLOC;
+		ext4_mb_normalize_request(ac, ar);
 
 repeat:
 		/* allocate space in core */
-		ext4_mb_regular_allocator(&ac);
+		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 (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);
+	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;
+		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);
+		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;
+		ac->ac_b_ex.fe_len = 0;
 		ar->len = 0;
-		ext4_mb_show_ac(&ac);
+		ext4_mb_show_ac(ac);
 	}
 
-	ext4_mb_release_context(&ac);
+	ext4_mb_release_context(ac);
 
 out:
 	if (ar->len < inquota)
 		DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
 
+	kmem_cache_free(ext4_ac_cachep, ac);
 	return block;
 }
 static void ext4_mb_poll_new_transaction(struct super_block *sb,
@@ -4405,9 +4442,9 @@ 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 buffer_head *bitmap_bh = NULL;
 	struct super_block *sb = inode->i_sb;
-	struct ext4_allocation_context ac;
+	struct ext4_allocation_context *ac = NULL;
 	struct ext4_group_desc *gdp;
 	struct ext4_super_block *es;
 	unsigned long overflow;
@@ -4436,9 +4473,12 @@ void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
 
 	ext4_debug("freeing block %lu\n", block);
 
-	ac.ac_op = EXT4_MB_HISTORY_FREE;
-	ac.ac_inode = inode;
-	ac.ac_sb = sb;
+	ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
+	if (ac) {
+		ac->ac_op = EXT4_MB_HISTORY_FREE;
+		ac->ac_inode = inode;
+		ac->ac_sb = sb;
+	}
 
 do_more:
 	overflow = 0;
@@ -4504,10 +4544,12 @@ do_more:
 	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 (ac) {
+		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
@@ -4548,5 +4590,7 @@ do_more:
 error_return:
 	brelse(bitmap_bh);
 	ext4_std_error(sb, err);
+	if (ac)
+		kmem_cache_free(ext4_ac_cachep, ac);
 	return;
 }
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 3ebc2332f52e..8c6c685b9d22 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -61,10 +61,9 @@ static int finish_range(handle_t *handle, struct inode *inode,
 		retval = ext4_journal_restart(handle, needed);
 		if (retval)
 			goto err_out;
-	}
-	if (needed) {
+	} else if (needed) {
 		retval = ext4_journal_extend(handle, needed);
-		if (retval != 0) {
+		if (retval) {
 			/*
 			 * IF not able to extend the journal restart the journal
 			 */
@@ -220,6 +219,26 @@ static int update_tind_extent_range(handle_t *handle, struct inode *inode,
 
 }
 
+static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode)
+{
+	int retval = 0, needed;
+
+	if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS)
+		return 0;
+	/*
+	 * We are freeing a blocks. During this we touch
+	 * superblock, group descriptor and block bitmap.
+	 * So allocate a credit of 3. We may update
+	 * quota (user and group).
+	 */
+	needed = 3 + 2*EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb);
+
+	if (ext4_journal_extend(handle, needed) != 0)
+		retval = ext4_journal_restart(handle, needed);
+
+	return retval;
+}
+
 static int free_dind_blocks(handle_t *handle,
 				struct inode *inode, __le32 i_data)
 {
@@ -234,11 +253,14 @@ static int free_dind_blocks(handle_t *handle,
 
 	tmp_idata = (__le32 *)bh->b_data;
 	for (i = 0; i < max_entries; i++) {
-		if (tmp_idata[i])
+		if (tmp_idata[i]) {
+			extend_credit_for_blkdel(handle, inode);
 			ext4_free_blocks(handle, inode,
 					le32_to_cpu(tmp_idata[i]), 1, 1);
+		}
 	}
 	put_bh(bh);
+	extend_credit_for_blkdel(handle, inode);
 	ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);
 	return 0;
 }
@@ -267,29 +289,32 @@ static int free_tind_blocks(handle_t *handle,
 		}
 	}
 	put_bh(bh);
+	extend_credit_for_blkdel(handle, inode);
 	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)
+static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
 {
 	int retval;
-	struct ext4_inode_info *ei = EXT4_I(inode);
 
-	if (ei->i_data[EXT4_IND_BLOCK])
+	/* ei->i_data[EXT4_IND_BLOCK] */
+	if (i_data[0]) {
+		extend_credit_for_blkdel(handle, inode);
 		ext4_free_blocks(handle, inode,
-				le32_to_cpu(ei->i_data[EXT4_IND_BLOCK]), 1, 1);
+				le32_to_cpu(i_data[0]), 1, 1);
+	}
 
-	if (ei->i_data[EXT4_DIND_BLOCK]) {
-		retval = free_dind_blocks(handle, inode,
-						ei->i_data[EXT4_DIND_BLOCK]);
+	/* ei->i_data[EXT4_DIND_BLOCK] */
+	if (i_data[1]) {
+		retval = free_dind_blocks(handle, inode, i_data[1]);
 		if (retval)
 			return retval;
 	}
 
-	if (ei->i_data[EXT4_TIND_BLOCK]) {
-		retval = free_tind_blocks(handle, inode,
-						ei->i_data[EXT4_TIND_BLOCK]);
+	/* ei->i_data[EXT4_TIND_BLOCK] */
+	if (i_data[2]) {
+		retval = free_tind_blocks(handle, inode, i_data[2]);
 		if (retval)
 			return retval;
 	}
@@ -297,15 +322,13 @@ static int free_ind_block(handle_t *handle, struct inode *inode)
 }
 
 static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
-				struct inode *tmp_inode, int retval)
+				struct inode *tmp_inode)
 {
+	int retval;
+	__le32	i_data[3];
 	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
@@ -317,6 +340,11 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
 			goto err_out;
 	}
 
+	i_data[0] = ei->i_data[EXT4_IND_BLOCK];
+	i_data[1] = ei->i_data[EXT4_DIND_BLOCK];
+	i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
+
+	down_write(&EXT4_I(inode)->i_data_sem);
 	/*
 	 * We have the extent map build with the tmp inode.
 	 * Now copy the i_data across
@@ -336,8 +364,15 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
 	spin_lock(&inode->i_lock);
 	inode->i_blocks += tmp_inode->i_blocks;
 	spin_unlock(&inode->i_lock);
+	up_write(&EXT4_I(inode)->i_data_sem);
 
+	/*
+	 * We mark the inode dirty after, because we decrement the
+	 * i_blocks when freeing the indirect meta-data blocks
+	 */
+	retval = free_ind_block(handle, inode, i_data);
 	ext4_mark_inode_dirty(handle, inode);
+
 err_out:
 	return retval;
 }
@@ -365,6 +400,7 @@ static int free_ext_idx(handle_t *handle, struct inode *inode,
 		}
 	}
 	put_bh(bh);
+	extend_credit_for_blkdel(handle, inode);
 	ext4_free_blocks(handle, inode, block, 1, 1);
 	return retval;
 }
@@ -414,7 +450,12 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp,
 	if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL))
 		return -EINVAL;
 
-	down_write(&EXT4_I(inode)->i_data_sem);
+	if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0)
+		/*
+		 * don't migrate fast symlink
+		 */
+		return retval;
+
 	handle = ext4_journal_start(inode,
 					EXT4_DATA_TRANS_BLOCKS(inode->i_sb) +
 					EXT4_INDEX_EXTRA_TRANS_BLOCKS + 3 +
@@ -448,13 +489,6 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp,
 	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.
@@ -463,7 +497,20 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp,
 	 * trascation that created the inode. Later as and
 	 * when we add extents we extent the journal
 	 */
+	/*
+	 * inode_mutex prevent write and truncate on the file. Read still goes
+	 * through. We take i_data_sem in ext4_ext_swap_inode_data before we
+	 * switch the inode format to prevent read.
+	 */
+	mutex_lock(&(inode->i_mutex));
 	handle = ext4_journal_start(inode, 1);
+
+	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;
 	for (i = 0; i < EXT4_NDIR_BLOCKS; i++, blk_count++) {
 		if (i_data[i]) {
 			retval = update_extent_range(handle, tmp_inode,
@@ -501,19 +548,6 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp,
 	 */
 	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
@@ -522,7 +556,11 @@ err_out:
 		free_ext_block(handle, tmp_inode);
 	else
 		retval = ext4_ext_swap_inode_data(handle, inode,
-							tmp_inode, retval);
+							tmp_inode);
+
+	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
+	if (ext4_journal_extend(handle, 1) != 0)
+		ext4_journal_restart(handle, 1);
 
 	/*
 	 * Mark the tmp_inode as of size zero
@@ -550,8 +588,7 @@ err_out:
 	tmp_inode->i_nlink = 0;
 
 	ext4_journal_stop(handle);
-
-	up_write(&EXT4_I(inode)->i_data_sem);
+	mutex_unlock(&(inode->i_mutex));
 
 	if (tmp_inode)
 		iput(tmp_inode);
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index d153bb5922fc..a9347fb43bcc 100644
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -2223,6 +2223,7 @@ retry:
 		inode->i_op = &ext4_fast_symlink_inode_operations;
 		memcpy((char*)&EXT4_I(inode)->i_data,symname,l);
 		inode->i_size = l-1;
+		EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
 	}
 	EXT4_I(inode)->i_disksize = inode->i_size;
 	err = ext4_add_nondir(handle, dentry, inode);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 93beb865c20d..0072da75221f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1919,6 +1919,17 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent)
 		printk(KERN_WARNING
 		       "EXT4-fs warning: feature flags set on rev 0 fs, "
 		       "running e2fsck is recommended\n");
+
+	/*
+	 * Since ext4 is still considered development code, we require
+	 * that the TEST_FILESYS flag in s->flags be set.
+	 */
+	if (!(le32_to_cpu(es->s_flags) & EXT2_FLAGS_TEST_FILESYS)) {
+		printk(KERN_WARNING "EXT4-fs: %s: not marked "
+		       "OK to use with test code.\n", sb->s_id);
+		goto failed_mount;
+	}
+
 	/*
 	 * Check feature flags regardless of the revision level, since we
 	 * previously didn't change the revision level when setting the flags,
diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 8e08efcaede2..a38c7186c570 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -104,7 +104,8 @@ static int journal_write_commit_record(journal_t *journal,
 {
 	struct journal_head *descriptor;
 	struct buffer_head *bh;
-	int i, ret;
+	journal_header_t *header;
+	int ret;
 	int barrier_done = 0;
 
 	if (is_journal_aborted(journal))
@@ -116,13 +117,10 @@ static int journal_write_commit_record(journal_t *journal,
 
 	bh = jh2bh(descriptor);
 
-	/* AKPM: buglet - add `i' to tmp! */
-	for (i = 0; i < bh->b_size; i += 512) {
-		journal_header_t *tmp = (journal_header_t*)bh->b_data;
-		tmp->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
-		tmp->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK);
-		tmp->h_sequence = cpu_to_be32(commit_transaction->t_tid);
-	}
+	header = (journal_header_t *)(bh->b_data);
+	header->h_magic = cpu_to_be32(JFS_MAGIC_NUMBER);
+	header->h_blocktype = cpu_to_be32(JFS_COMMIT_BLOCK);
+	header->h_sequence = cpu_to_be32(commit_transaction->t_tid);
 
 	JBUFFER_TRACE(descriptor, "write commit block");
 	set_buffer_dirty(bh);
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 4f302d279279..a8173081f831 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -136,18 +136,20 @@ static int journal_submit_commit_record(journal_t *journal,
 
 	JBUFFER_TRACE(descriptor, "submit commit block");
 	lock_buffer(bh);
-
+	get_bh(bh);
 	set_buffer_dirty(bh);
 	set_buffer_uptodate(bh);
 	bh->b_end_io = journal_end_buffer_io_sync;
 
 	if (journal->j_flags & JBD2_BARRIER &&
-		!JBD2_HAS_COMPAT_FEATURE(journal,
+		!JBD2_HAS_INCOMPAT_FEATURE(journal,
 					 JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) {
 		set_buffer_ordered(bh);
 		barrier_done = 1;
 	}
 	ret = submit_bh(WRITE, bh);
+	if (barrier_done)
+		clear_buffer_ordered(bh);
 
 	/* is it possible for another commit to fail at roughly
 	 * the same time as this one?  If so, we don't want to
@@ -166,7 +168,6 @@ static int journal_submit_commit_record(journal_t *journal,
 		spin_unlock(&journal->j_state_lock);
 
 		/* And try again, without the barrier */
-		clear_buffer_ordered(bh);
 		set_buffer_uptodate(bh);
 		set_buffer_dirty(bh);
 		ret = submit_bh(WRITE, bh);
@@ -872,7 +873,8 @@ wait_for_iobuf:
 		if (err)
 			__jbd2_journal_abort_hard(journal);
 	}
-	err = journal_wait_on_commit_record(cbh);
+	if (!err && !is_journal_aborted(journal))
+		err = journal_wait_on_commit_record(cbh);
 
 	if (err)
 		jbd2_journal_abort(journal, err);
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index d36356f7d222..146411387ada 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -641,7 +641,7 @@ static int do_one_pass(journal_t *journal,
 				if (chksum_err) {
 					info->end_transaction = next_commit_ID;
 
-					if (!JBD2_HAS_COMPAT_FEATURE(journal,
+					if (!JBD2_HAS_INCOMPAT_FEATURE(journal,
 					   JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)){
 						printk(KERN_ERR
 						       "JBD: Transaction %u "
diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h
index c4f635a4dd25..250032548597 100644
--- a/include/linux/ext4_fs.h
+++ b/include/linux/ext4_fs.h
@@ -490,6 +490,13 @@ do {									       \
 #define	EXT4_ORPHAN_FS			0x0004	/* Orphans being recovered */
 
 /*
+ * Misc. filesystem flags
+ */
+#define EXT2_FLAGS_SIGNED_HASH		0x0001  /* Signed dirhash in use */
+#define EXT2_FLAGS_UNSIGNED_HASH	0x0002  /* Unsigned dirhash in use */
+#define EXT2_FLAGS_TEST_FILESYS		0x0004	/* to test development code */
+
+/*
  * Mount flags
  */
 #define EXT4_MOUNT_CHECK		0x00001	/* Do mount-time checks */