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authorAlex Elder <elder@dreamhost.com>2012-04-04 13:35:44 -0500
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-11-26 11:38:10 -0800
commit095cb2142dfb10daea5a3351ed9646d3178a6823 (patch)
tree32290c2d2277d3a95e3f40b1825295ab3dd215e9 /drivers/block/rbd.c
parent49da293c7dc4401c2c7963a2c70f633b1c8fa8c5 (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/rbd.c')
-rw-r--r--drivers/block/rbd.c4
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;
}