2008-03-20 00:11:53

by Andrew Morton

[permalink] [raw]
Subject: [patch 19/35] jbd2: correctly unescape journal data blocks

From: "Duane Griffin" <[email protected]>

Fix a long-standing typo (predating git) that will cause data corruption if a
journal data block needs unescaping. At the moment the wrong buffer head's
data is being unescaped.

To test this case mount a filesystem with data=journal, start creating and
deleting a bunch of files containing only JBD2_MAGIC_NUMBER (0xc03b3998), then
pull the plug on the device. Without this patch the files will contain zeros
instead of the correct data after recovery.

Signed-off-by: Duane Griffin <[email protected]>
Acked-by: Jan Kara <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

fs/jbd2/recovery.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff -puN fs/jbd2/recovery.c~jbd2-correctly-unescape-journal-data-blocks fs/jbd2/recovery.c
--- a/fs/jbd2/recovery.c~jbd2-correctly-unescape-journal-data-blocks
+++ a/fs/jbd2/recovery.c
@@ -535,7 +535,7 @@ static int do_one_pass(journal_t *journa
memcpy(nbh->b_data, obh->b_data,
if (flags & JBD2_FLAG_ESCAPE) {
- *((__be32 *)bh->b_data) =
+ *((__be32 *)nbh->b_data) =