Andrew Morton wrote:
>On Sat, 5 Jan 2008 09:52:15 -0800 (PST)
bugme-daemon@xxxxxxxxxxxxxxxxxxx wrote:
>> http://bugzilla.kernel.org/show_bug.cgi?id=9692
>>
>> Summary: journal_data mount option causes filesystem
corruption
>> with blocksize != 4096
>> Product: File System
>> Version: 2.5
>> KernelVersion: 2.6.23.9
>> Platform: All
>> OS/Version: Linux
>> Tree: Mainline
>> Status: NEW
>> Severity: high
>> Priority: P1
>> Component: ext3
>> AssignedTo: akpm@xxxxxxxx
>> ReportedBy: h.judt@xxxxxx
This looks to be an off-by-one bug with e2fsck in the function
check_blocks(), and there isn't any actual filesystem corruption
(e2fsck causes the corruption).
Please see the attached patch, which fixes the problem for me.
Jayson King
>From 654f24814e7b80d3b16bec2a67c13c43cb20eb2f Mon Sep 17 00:00:00 2001
From: Jayson R. King <dev@xxxxxxxxxxxxxx>
Date: Sun, 6 Jan 2008 18:14:18 -0600
Subject: e2fsck: Fix off-by-one error in check_blocks()
e2fsck allows extra blocks to be allocated to an inode up to the next
multiple of page size iff the block size is not equal to page size. An
off-by-one error in checking for this causes e2fsck to wrongly detect
a bad i_size for such inodes and results in incorrectly adjusting the
i_size to include those blocks.
Signed-off-by: Jayson R. King <dev@xxxxxxxxxxxxxx>
---
e2fsck/pass1.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 56218ae..7bf0686 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -1593,7 +1593,7 @@ static void check_blocks(e2fsck_t ctx, struct problem_context *pctx,
if ((pb.last_block >= 0) &&
/* allow allocated blocks to end of PAGE_SIZE */
(size < (__u64)pb.last_block * fs->blocksize) &&
- (pb.last_block / blkpg * blkpg != pb.last_block ||
+ ((pb.last_block+1) & (blkpg-1) != 0 ||
size < (__u64)(pb.last_block & ~(blkpg-1)) *fs->blocksize))
bad_size = 3;
else if (size > ext2_max_sizes[fs->super->s_log_block_size])
--
1.5.3.3
