On Wed, Jul 06, 2011 at 08:32:03AM +0200, Arkadiusz Miskiewicz wrote:
>
> quota check code (mount with user+group quota) likes to oops
> for me (usually after system hang and hard reset).
>
> This is on 2.6.38.8 on top of raid10 soft raid. Mount without
> quota succeeds without a problem.
Looking over the oops mutex_lock is dereferencing a member at offset
0x20 of a structure that unexpectly is a NULL pointer. The only
mutex_lock calls in xfs_qm_sync are on qi_dqlist_lock, which happens
to be exactly at the offset 0x20 that the oops is complaining about.
So the quick patch below should prevent the OOPS for you and print
a warnings instead, although I'll have to dig a bit deeper to figure
out the root cause.
Index: linux-2.6/fs/xfs/quota/xfs_qm.c
===================================================================
--- linux-2.6.orig/fs/xfs/quota/xfs_qm.c 2011-07-07 15:02:25.206920700
+0200
+++ linux-2.6/fs/xfs/quota/xfs_qm.c 2011-07-07 15:03:59.576915891 +0200
@@ -939,6 +939,11 @@ xfs_qm_sync(
restarts = 0;
again:
+ if (!q) {
+ printk("XFS: %s called without valid quotainfo\n", __func__);
+ dump_stack();
+ return 0;
+ }
mutex_lock(&q->qi_dqlist_lock);
/*
* dqpurge_all() also takes the mplist lock and iterate thru all dquots
@@ -1003,6 +1008,12 @@ xfs_qm_sync(
else if (error)
return error;
+ if (!q) {
+ printk("XFS: %s called without valid quotainfo (2)\n",
+ __func__);
+ dump_stack();
+ return 0;
+ }
mutex_lock(&q->qi_dqlist_lock);
if (recl != q->qi_dqreclaims) {
if (++restarts >= XFS_QM_SYNC_MAX_RESTARTS)
|