xfs: fix dquot isolation hang
The new LRU list isolation code in xfs_qm_dquot_isolate() isn't
completely up to date. Firstly, it needs conversion to return enum
lru_status values, not raw numbers. Secondly - most importantly - it
fails to unlock the dquot and relock the LRU in the LRU_RETRY path.
This leads to deadlocks in xfstests generic/232. Fix them.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index 1a4217e..a29169b 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -707,7 +707,7 @@
trace_xfs_dqreclaim_want(dqp);
list_del_init(&dqp->q_lru);
XFS_STATS_DEC(xs_qm_dquot_unused);
- return 0;
+ return LRU_REMOVED;
}
/*
@@ -753,17 +753,19 @@
XFS_STATS_DEC(xs_qm_dquot_unused);
trace_xfs_dqreclaim_done(dqp);
XFS_STATS_INC(xs_qm_dqreclaims);
- return 0;
+ return LRU_REMOVED;
out_miss_busy:
trace_xfs_dqreclaim_busy(dqp);
XFS_STATS_INC(xs_qm_dqreclaim_misses);
- return 2;
+ return LRU_SKIP;
out_unlock_dirty:
trace_xfs_dqreclaim_busy(dqp);
XFS_STATS_INC(xs_qm_dqreclaim_misses);
- return 3;
+ xfs_dqunlock(dqp);
+ spin_lock(lru_lock);
+ return LRU_RETRY;
}
static unsigned long