Commit 780dcdb2 authored Jul 26, 2007 by Eric Sandeen Committed by Linus Torvalds Jul 26, 2007

fix inode_table test in ext234_check_descriptors



ext[234]_check_descriptors sanity checks block group descriptor geometry at
mount time, testing whether the block bitmap, inode bitmap, and inode table
reside wholly within the blockgroup.  However, the inode table test is off
by one so that if the last block in the inode table resides on the last
block of the block group, the test incorrectly fails.  This is because it
tests the last block as (start + length) rather than (start + length - 1).

This can be seen by trying to mount a filesystem made such as:

 mkfs.ext2 -F -b 1024 -m 0 -g 256 -N 3744 fsfile 1024

which yields:

 EXT2-fs error (device loop0): ext2_check_descriptors: Inode table for group 0 not in group (block 101)!
 EXT2-fs: group descriptors corrupted!

There is a similar bug in e2fsprogs, patch already sent for that.

(I wonder if inside(), outside(), and/or in_range() should someday be
used in this and other tests throughout the ext filesystems...)

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 98ac0e53

fs/ext2/super.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -580,7 +580,7 @@ static int ext2_check_descriptors (struct super_block * sb)
		return 0;
		}
		if (le32_to_cpu(gdp->bg_inode_table) < first_block \|\|
		le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
		le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
		last_block)
		{
		ext2_error (sb, "ext2_check_descriptors",

fs/ext3/super.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1221,7 +1221,7 @@ static int ext3_check_descriptors (struct super_block * sb)
		return 0;
		}
		if (le32_to_cpu(gdp->bg_inode_table) < first_block \|\|
		le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group >
		le32_to_cpu(gdp->bg_inode_table) + sbi->s_itb_per_group - 1 >
		last_block)
		{
		ext3_error (sb, "ext3_check_descriptors",

fs/ext4/super.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1283,7 +1283,7 @@ static int ext4_check_descriptors (struct super_block * sb)
		}
		inode_table = ext4_inode_table(sb, gdp);
		if (inode_table < first_block \|\|
		inode_table + sbi->s_itb_per_group > last_block)
		inode_table + sbi->s_itb_per_group - 1 > last_block)
		{
		ext4_error (sb, "ext4_check_descriptors",
		"Inode table for group %d"

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