Commit 8636ea67 authored Jul 30, 2012 by Sage Weil

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>

parent 7b862e07

net/ceph/messenger.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -2336,7 +2336,6 @@ done_unlocked:
		return;

		fault:
		mutex_unlock(&con->mutex);
		ceph_fault(con); /* error/fault path */
		goto done_unlocked;
		}
		@@ -2347,9 +2346,8 @@ fault:
		* 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",