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| author | Mikulas Patocka <mpatocka@redhat.com> | 2014-11-05 17:00:13 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-08 10:30:19 -0800 |
| commit | ffcc89dbcbe470f537aa104bb84cbf3eed77d67d (patch) | |
| tree | 383ade16885ebf63df4534aa4195a59f82e97988 /drivers/md | |
| parent | 2409f5131d09a7a1e2a0a69ee4fb7788954de5cf (diff) | |
| download | lwn-ffcc89dbcbe470f537aa104bb84cbf3eed77d67d.tar.gz lwn-ffcc89dbcbe470f537aa104bb84cbf3eed77d67d.zip | |
dm thin: fix a race in thin_dtr
commit 17181fb7a0c3a279196c0eeb2caba65a1519614b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md')
| -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 3ae87a39e4c9..aae19133cfac 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -3266,14 +3266,14 @@ 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); |