diff options
author | Dave Chinner <dchinner@redhat.com> | 2012-11-28 13:01:02 +1100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-01-11 09:18:53 -0800 |
commit | f8b723cc9f1a9eec83c8527d67eedc6249b7fb66 (patch) | |
tree | 19eecb7f9b2e5a377ad21f87b3c425c6471859bb /fs | |
parent | 82251473514fde36ce8dc0167f41eaf7ef6a4cb9 (diff) |
xfs: fix stray dquot unlock when reclaiming dquots
commit b870553cdecb26d5291af09602352b763e323df2 upstream.
When we fail to get a dquot lock during reclaim, we jump to an error
handler that unlocks the dquot. This is wrong as we didn't lock the
dquot, and unlocking it means who-ever is holding the lock has had
it silently taken away, and hence it results in a lock imbalance.
Found by inspection while modifying the code for the numa-lru
patchset. This fixes a random hang I've been seeing on xfstest 232
for the past several months.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/xfs/xfs_qm.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c index 2e86fa0cfc0d..335a34041ea1 100644 --- a/fs/xfs/xfs_qm.c +++ b/fs/xfs/xfs_qm.c @@ -1453,7 +1453,7 @@ xfs_qm_dqreclaim_one( int error; if (!xfs_dqlock_nowait(dqp)) - goto out_busy; + goto out_move_tail; /* * This dquot has acquired a reference in the meantime remove it from @@ -1476,7 +1476,7 @@ xfs_qm_dqreclaim_one( * getting flushed to disk, we don't want to reclaim it. */ if (!xfs_dqflock_nowait(dqp)) - goto out_busy; + goto out_unlock_move_tail; if (XFS_DQ_IS_DIRTY(dqp)) { struct xfs_buf *bp = NULL; @@ -1487,7 +1487,7 @@ xfs_qm_dqreclaim_one( if (error) { xfs_warn(mp, "%s: dquot %p flush failed", __func__, dqp); - goto out_busy; + goto out_unlock_move_tail; } xfs_buf_delwri_queue(bp, buffer_list); @@ -1496,7 +1496,7 @@ xfs_qm_dqreclaim_one( * Give the dquot another try on the freelist, as the * flushing will take some time. */ - goto out_busy; + goto out_unlock_move_tail; } xfs_dqfunlock(dqp); @@ -1515,14 +1515,13 @@ xfs_qm_dqreclaim_one( XFS_STATS_INC(xs_qm_dqreclaims); return; -out_busy: - xfs_dqunlock(dqp); - /* * Move the dquot to the tail of the list so that we don't spin on it. */ +out_unlock_move_tail: + xfs_dqunlock(dqp); +out_move_tail: list_move_tail(&dqp->q_lru, &qi->qi_lru_list); - trace_xfs_dqreclaim_busy(dqp); XFS_STATS_INC(xs_qm_dqreclaim_misses); } |