[30/39] XFS bug in log recover with quota (bugzilla id 855)

[Greg KH <gregkh@suse.de>]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Jan Rekorajski <baggins@sith.mimuw.edu.pl>

commit 8ec6dba2581754e375be66f7bedd708d856d8b30 upstream.

Hi,
I was hit by a bug in linux 2.6.31 when XFS is not able to recover the
log after a crash if fs was mounted with quotas. Gory details in XFS
bugzilla: http://oss.sgi.com/bugzilla/show_bug.cgi?id=855.

It looks like wrong struct is used in buffer length check, and the following
patch should fix the problem.

xfs_dqblk_t has a size of 104+32 bytes, while xfs_disk_dquot_t is 104 bytes
long, and this is exactly what I see in system logs - "XFS: dquot too small
(104) in xlog_recover_do_dquot_trans."

Signed-off-by: Jan Rekorajski <baggins@sith.mimuw.edu.pl>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
Cc: Simon Kirby <sim@hostway.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/xfs/xfs_log_recover.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1980,7 +1980,7 @@ xlog_recover_do_reg_buffer(
 					"XFS: NULL dquot in %s.", __func__);
 				goto next;
 			}
-			if (item->ri_buf[i].i_len < sizeof(xfs_dqblk_t)) {
+			if (item->ri_buf[i].i_len < sizeof(xfs_disk_dquot_t)) {
 				cmn_err(CE_ALERT,
 					"XFS: dquot too small (%d) in %s.",
 					item->ri_buf[i].i_len, __func__);
@@ -2635,7 +2635,7 @@ xlog_recover_do_dquot_trans(
 			"XFS: NULL dquot in %s.", __func__);
 		return XFS_ERROR(EIO);
 	}
-	if (item->ri_buf[1].i_len < sizeof(xfs_dqblk_t)) {
+	if (item->ri_buf[1].i_len < sizeof(xfs_disk_dquot_t)) {
 		cmn_err(CE_ALERT,
 			"XFS: dquot too small (%d) in %s.",
 			item->ri_buf[1].i_len, __func__);