XFS bug in log recover with quota (bugzilla id 855)

[Jan Rekorajski]

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."

--- linux-2.6.31.5/fs/xfs/xfs_log_recover.c.orig	2009-11-01 23:59:52.194846209 +0100
+++ linux-2.6.31.5/fs/xfs/xfs_log_recover.c	2009-11-16 12:47:11.601490963 +0100
@@ -1980,7 +1980,7 @@
 					"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__);
@@ -2636,7 +2636,7 @@
 			"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__);

-- 
Jan Rekorajski            |  ALL SUSPECTS ARE GUILTY. PERIOD!
baggins<at>mimuw.edu.pl   |  OTHERWISE THEY WOULDN'T BE SUSPECTS, WOULD THEY?
BOFH, MANIAC              |                   -- TROOPS by Kevin Rubio