diff options
| author | Mikulas Patocka | 2014-11-05 23:00:13 +0100 |
|---|---|---|
| committer | Mike Snitzer | 2014-11-13 02:15:04 +0100 |
| commit | 17181fb7a0c3a279196c0eeb2caba65a1519614b (patch) | |
| tree | e8f9d8b7b2134f55e75fca41b9d4fa0165e2f088 | |
| parent | dm cache: emit a warning message if there are a lot of cache blocks (diff) | |
| download | kernel-qcow2-linux-17181fb7a0c3a279196c0eeb2caba65a1519614b.tar.gz kernel-qcow2-linux-17181fb7a0c3a279196c0eeb2caba65a1519614b.tar.xz kernel-qcow2-linux-17181fb7a0c3a279196c0eeb2caba65a1519614b.zip | |
dm thin: fix a race in thin_dtr
As long as struct thin_c is in the list, anyone can grab a reference of
it. Consequently, we must wait for the reference count to drop to zero
*after* we remove the structure from the list, not before.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
| -rw-r--r-- | drivers/md/dm-thin.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 8c5504c0e894..767417a28b6f 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -3622,14 +3622,14 @@ static void thin_dtr(struct dm_target *ti) struct thin_c *tc = ti->private; unsigned long flags; - thin_put(tc); - wait_for_completion(&tc->can_destroy); - spin_lock_irqsave(&tc->pool->lock, flags); list_del_rcu(&tc->list); spin_unlock_irqrestore(&tc->pool->lock, flags); synchronize_rcu(); + thin_put(tc); + wait_for_completion(&tc->can_destroy); + mutex_lock(&dm_thin_pool_table.mutex); __pool_dec(tc->pool); |