diff options
| author | Alex Elder <elder@dreamhost.com> | 2012-04-04 13:35:44 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-26 11:38:10 -0800 |
| commit | 095cb2142dfb10daea5a3351ed9646d3178a6823 (patch) | |
| tree | 32290c2d2277d3a95e3f40b1825295ab3dd215e9 /drivers/block | |
| parent | 49da293c7dc4401c2c7963a2c70f633b1c8fa8c5 (diff) | |
rbd: don't hold spinlock during messenger flush
(cherry picked from commit cd9d9f5df6098c50726200d4185e9e8da32785b3)
A recent change made changes to the rbd_client_list be protected by
a spinlock. Unfortunately in rbd_put_client(), the lock is taken
before possibly dropping the last reference to an rbd_client, and on
the last reference that eventually calls flush_workqueue() which can
sleep.
The problem was flagged by a debug spinlock warning:
BUG: spinlock wrong CPU on CPU#3, rbd/27814
The solution is to move the spinlock acquisition and release inside
rbd_client_release(), which is the spot where it's really needed for
protecting the removal of the rbd_client from the client list.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/rbd.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 013c7a549fb..c1f77013165 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -450,7 +450,9 @@ static void rbd_client_release(struct kref *kref) struct rbd_client *rbdc = container_of(kref, struct rbd_client, kref); dout("rbd_release_client %p\n", rbdc); + spin_lock(&rbd_client_list_lock); list_del(&rbdc->node); + spin_unlock(&rbd_client_list_lock); ceph_destroy_client(rbdc->client); kfree(rbdc->rbd_opts); @@ -463,9 +465,7 @@ static void rbd_client_release(struct kref *kref) */ static void rbd_put_client(struct rbd_device *rbd_dev) { - spin_lock(&rbd_client_list_lock); kref_put(&rbd_dev->rbd_client->kref, rbd_client_release); - spin_unlock(&rbd_client_list_lock); rbd_dev->rbd_client = NULL; } |