libceph: avoid dropping con mutex before fault
The ceph_fault() function takes the con mutex, so we should avoid
dropping it before calling it. This fixes a potential race with
another thread calling ceph_con_close(), or _open(), or similar (we
don't reverify con->state after retaking the lock).
Add annotation so that lockdep realizes we will drop the mutex before
returning.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index feb5a2a..c3b628c 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2336,7 +2336,6 @@
return;
fault:
- mutex_unlock(&con->mutex);
ceph_fault(con); /* error/fault path */
goto done_unlocked;
}
@@ -2347,9 +2346,8 @@
* exponential backoff
*/
static void ceph_fault(struct ceph_connection *con)
+ __releases(con->mutex)
{
- mutex_lock(&con->mutex);
-
pr_err("%s%lld %s %s\n", ENTITY_NAME(con->peer_name),
ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg);
dout("fault %p state %lu to peer %s\n",