From: Dave Chinner <dchinner@xxxxxxxxxx>
Commit 368e136 ("xfs: remove duplicate code from dquot reclaim") fails
to unlock the dquot freelist when the number of loop restarts is
exceeded in xfs_qm_dqreclaim_one(). This causes hangs in memory
reclaim. Remove the bogus loop exit check that causes the problem.
Reported-by: Malcolm Scott <lkml@xxxxxxxxxxx>
Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
fs/xfs/quota/xfs_qm.c | 46 +++++++++++++++++++++-------------------------
1 files changed, 21 insertions(+), 25 deletions(-)
diff --git a/fs/xfs/quota/xfs_qm.c b/fs/xfs/quota/xfs_qm.c
index f8e854b..206a281 100644
--- a/fs/xfs/quota/xfs_qm.c
+++ b/fs/xfs/quota/xfs_qm.c
@@ -1863,12 +1863,14 @@ xfs_qm_dqreclaim_one(void)
xfs_dquot_t *dqpout;
xfs_dquot_t *dqp;
int restarts;
+ int startagain;
restarts = 0;
dqpout = NULL;
/* lockorder: hashchainlock, freelistlock, mplistlock, dqlock, dqflock */
-startagain:
+again:
+ startagain = 0;
mutex_lock(&xfs_Gqm->qm_dqfrlist_lock);
list_for_each_entry(dqp, &xfs_Gqm->qm_dqfrlist, q_freelist) {
@@ -1885,13 +1887,10 @@ startagain:
ASSERT(! (dqp->dq_flags & XFS_DQ_INACTIVE));
trace_xfs_dqreclaim_want(dqp);
-
- xfs_dqunlock(dqp);
- mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
- if (++restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
- return NULL;
XQM_STATS_INC(xqmstats.xs_qm_dqwants);
- goto startagain;
+ restarts++;
+ startagain = 1;
+ goto dqunlock;
}
/*
@@ -1906,23 +1905,20 @@ startagain:
ASSERT(list_empty(&dqp->q_mplist));
list_del_init(&dqp->q_freelist);
xfs_Gqm->qm_dqfrlist_cnt--;
- xfs_dqunlock(dqp);
dqpout = dqp;
XQM_STATS_INC(xqmstats.xs_qm_dqinact_reclaims);
- break;
+ goto dqunlock;
}
ASSERT(dqp->q_hash);
ASSERT(!list_empty(&dqp->q_mplist));
/*
- * Try to grab the flush lock. If this dquot is in the process of
- * getting flushed to disk, we don't want to reclaim it.
+ * Try to grab the flush lock. If this dquot is in the process
+ * of getting flushed to disk, we don't want to reclaim it.
*/
- if (!xfs_dqflock_nowait(dqp)) {
- xfs_dqunlock(dqp);
- continue;
- }
+ if (!xfs_dqflock_nowait(dqp))
+ goto dqunlock;
/*
* We have the flush lock so we know that this is not in the
@@ -1944,8 +1940,7 @@ startagain:
xfs_fs_cmn_err(CE_WARN, mp,
"xfs_qm_dqreclaim: dquot %p flush failed", dqp);
}
- xfs_dqunlock(dqp); /* dqflush unlocks dqflock */
- continue;
+ goto dqunlock;
}
/*
@@ -1967,13 +1962,8 @@ startagain:
*/
if (!mutex_trylock(&mp->m_quotainfo->qi_dqlist_lock)) {
restarts++;
- mutex_unlock(&dqp->q_hash->qh_lock);
- xfs_dqfunlock(dqp);
- xfs_dqunlock(dqp);
- mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
- if (restarts++ >= XFS_QM_RECLAIM_MAX_RESTARTS)
- return NULL;
- goto startagain;
+ startagain = 1;
+ goto qhunlock;
}
ASSERT(dqp->q_nrefs == 0);
@@ -1986,14 +1976,20 @@ startagain:
xfs_Gqm->qm_dqfrlist_cnt--;
dqpout = dqp;
mutex_unlock(&mp->m_quotainfo->qi_dqlist_lock);
+qhunlock:
mutex_unlock(&dqp->q_hash->qh_lock);
dqfunlock:
xfs_dqfunlock(dqp);
+dqunlock:
xfs_dqunlock(dqp);
if (dqpout)
break;
if (restarts >= XFS_QM_RECLAIM_MAX_RESTARTS)
- return NULL;
+ break;
+ if (startagain) {
+ mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
+ goto again;
+ }
}
mutex_unlock(&xfs_Gqm->qm_dqfrlist_lock);
return dqpout;
--
1.7.2.3
_______________________________________________
xfs mailing list
xfs@xxxxxxxxxxx
http://oss.sgi.com/mailman/listinfo/xfs
