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| author | Alex Elder <elder@dreamhost.com> | 2012-04-04 13:35:44 -0500 |
|---|---|---|
| committer | Alex Elder <elder@dreamhost.com> | 2012-04-05 15:43:58 -0500 |
| commit | cd9d9f5df6098c50726200d4185e9e8da32785b3 (patch) | |
| tree | 94e4c7035fc7c7f6596a8f3b59fa27e19a45d4f0 /drivers/block | |
| parent | c666601a935b94cc0f3310339411b6940de751ba (diff) | |
| download | linux-stable-cd9d9f5df6098c50726200d4185e9e8da32785b3.tar.gz linux-stable-cd9d9f5df6098c50726200d4185e9e8da32785b3.tar.bz2 linux-stable-cd9d9f5df6098c50726200d4185e9e8da32785b3.zip | |
rbd: don't hold spinlock during messenger flush
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>
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 013c7a549fb6..c1f770131654 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; } |