The following are all bug fixes and regressions. The most notable are

the ones which cause problems for ext4 on RAID --- a performance
 problem when mounting very large filesystems, and a kernel OOPS when
 doing an rm -rf on large directory hierarchies on fast devices.
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Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bug fixes from Ted Ts'o:
 "The following are all bug fixes and regressions.  The most notable are
  the ones which cause problems for ext4 on RAID --- a performance
  problem when mounting very large filesystems, and a kernel OOPS when
  doing an rm -rf on large directory hierarchies on fast devices."

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix kernel BUG on large-scale rm -rf commands
  ext4: fix long mount times on very big file systems
  ext4: don't call ext4_error while block group is locked
  ext4: avoid kmemcheck complaint from reading uninitialized memory
  ext4: make sure the journal sb is written in ext4_clear_journal_err()

fs/ext4/balloc.c

@@ -280,14 +280,18 @@ 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)
+/*
+ * Return the block number which was discovered to be invalid, or 0 if
+ * the block bitmap is valid.
+ */
+static ext4_fsblk_t 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 blk;
 	ext4_fsblk_t group_first_block;
 
 	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {
@@ -297,37 +301,33 @@ static int ext4_valid_block_bitmap(struct super_block *sb,
 		 * or it has to also read the block group where the bitmaps
 		 * are located to verify they are set.
 		 */
-		return 1;
+		return 0;
 	}
 	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;
+	blk = ext4_block_bitmap(sb, desc);
+	offset = blk - group_first_block;
 	if (!ext4_test_bit(offset, bh->b_data))
 		/* bad block bitmap */
-		goto err_out;
+		return blk;
 
 	/* check whether the inode bitmap block number is set */
-	bitmap_blk = ext4_inode_bitmap(sb, desc);
-	offset = bitmap_blk - group_first_block;
+	blk = ext4_inode_bitmap(sb, desc);
+	offset = blk - group_first_block;
 	if (!ext4_test_bit(offset, bh->b_data))
 		/* bad block bitmap */
-		goto err_out;
+		return blk;
 
 	/* check whether the inode table block number is set */
-	bitmap_blk = ext4_inode_table(sb, desc);
-	offset = bitmap_blk - group_first_block;
+	blk = ext4_inode_table(sb, desc);
+	offset = 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, "Invalid block bitmap - block_group = %d, block = %llu",
-			block_group, bitmap_blk);
+	if (next_zero_bit < offset + EXT4_SB(sb)->s_itb_per_group)
+		/* bad bitmap for inode tables */
+		return blk;
 	return 0;
 }
 
@@ -336,14 +336,26 @@ void ext4_validate_block_bitmap(struct super_block *sb,
 			       unsigned int block_group,
 			       struct buffer_head *bh)
 {
+	ext4_fsblk_t	blk;
+
 	if (buffer_verified(bh))
 		return;
 
 	ext4_lock_group(sb, block_group);
-	if (ext4_valid_block_bitmap(sb, desc, block_group, bh) &&
-	    ext4_block_bitmap_csum_verify(sb, block_group, desc, bh,
-					  EXT4_BLOCKS_PER_GROUP(sb) / 8))
-		set_buffer_verified(bh);
+	blk = ext4_valid_block_bitmap(sb, desc, block_group, bh);
+	if (unlikely(blk != 0)) {
+		ext4_unlock_group(sb, block_group);
+		ext4_error(sb, "bg %u: block %llu: invalid block bitmap",
+			   block_group, blk);
+		return;
+	}
+	if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
+			desc, bh, EXT4_BLOCKS_PER_GROUP(sb) / 8))) {
+		ext4_unlock_group(sb, block_group);
+		ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
+		return;
+	}
+	set_buffer_verified(bh);
 	ext4_unlock_group(sb, block_group);
 }
 

fs/ext4/bitmap.c

@@ -79,7 +79,6 @@ int ext4_block_bitmap_csum_verify(struct super_block *sb, ext4_group_t group,
 	if (provided == calculated)
 		return 1;
 
-	ext4_error(sb, "Bad block bitmap checksum: block_group = %u", group);
 	return 0;
 }
 

fs/ext4/extents.c

@@ -2662,6 +2662,7 @@ static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
 		}
 		path[0].p_depth = depth;
 		path[0].p_hdr = ext_inode_hdr(inode);
+		i = 0;
 
 		if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
 			err = -EIO;

fs/ext4/super.c

@@ -948,6 +948,7 @@ static struct inode *ext4_alloc_inode(struct super_block *sb)
 	ei->i_reserved_meta_blocks = 0;
 	ei->i_allocated_meta_blocks = 0;
 	ei->i_da_metadata_calc_len = 0;
+	ei->i_da_metadata_calc_last_lblock = 0;
 	spin_lock_init(&(ei->i_block_reservation_lock));
 #ifdef CONFIG_QUOTA
 	ei->i_reserved_quota = 0;
@@ -3108,6 +3109,10 @@ static int count_overhead(struct super_block *sb, ext4_group_t grp,
 	ext4_group_t		i, ngroups = ext4_get_groups_count(sb);
 	int			s, j, count = 0;
 
+	if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_BIGALLOC))
+		return (ext4_bg_has_super(sb, grp) + ext4_bg_num_gdb(sb, grp) +
+			sbi->s_itb_per_group + 2);
+
 	first_block = le32_to_cpu(sbi->s_es->s_first_data_block) +
 		(grp * EXT4_BLOCKS_PER_GROUP(sb));
 	last_block = first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1;
@@ -4419,6 +4424,7 @@ static void ext4_clear_journal_err(struct super_block *sb,
 		ext4_commit_super(sb, 1);
 
 		jbd2_journal_clear_err(journal);
+		jbd2_journal_update_sb_errno(journal);
 	}
 }
 

fs/jbd2/journal.c

@@ -1377,7 +1377,7 @@ static void jbd2_mark_journal_empty(journal_t *journal)
  * Update a journal's errno.  Write updated superblock to disk waiting for IO
  * to complete.
  */
-static void jbd2_journal_update_sb_errno(journal_t *journal)
+void jbd2_journal_update_sb_errno(journal_t *journal)
 {
 	journal_superblock_t *sb = journal->j_superblock;
 
@@ -1390,6 +1390,7 @@ static void jbd2_journal_update_sb_errno(journal_t *journal)
 
 	jbd2_write_superblock(journal, WRITE_SYNC);
 }
+EXPORT_SYMBOL(jbd2_journal_update_sb_errno);
 
 /*
  * Read the superblock for a given journal, performing initial

include/linux/jbd2.h

@@ -1125,6 +1125,7 @@ extern int	   jbd2_journal_destroy    (journal_t *);
 extern int	   jbd2_journal_recover    (journal_t *journal);
 extern int	   jbd2_journal_wipe       (journal_t *, int);
 extern int	   jbd2_journal_skip_recovery	(journal_t *);
+extern void	   jbd2_journal_update_sb_errno(journal_t *);
 extern void	   jbd2_journal_update_sb_log_tail	(journal_t *, tid_t,
 				unsigned long, int);
 extern void	   __jbd2_journal_abort_hard	(journal_t *);