commit 6c2838fbdedb9b72a81c931d49e56b229b6cdbca
author Jeff Layton <jlayton@redhat.com> Thu Oct 19 08:52:58 2017 -0400
committer Ilya Dryomov <idryomov@gmail.com> Wed Oct 25 08:31:15 2017 +0200
tree ee717ca5689cc898b7d7e9ac07739067dae2bf61
parent bb176f67090ca54869fc1262c913aa69d2ede070

ceph: unlock dangling spinlock in try_flush_caps()

sparse warns:

  fs/ceph/caps.c:2042:9: warning: context imbalance in 'try_flush_caps' - wrong count at exit

We need to exit this function with the lock unlocked, but a couple of
cases leave it locked.

Cc: stable@vger.kernel.org
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/caps.c

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 157fe59..1978a8c 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1991,6 +1991,7 @@
 retry:
 	spin_lock(&ci->i_ceph_lock);
 	if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
+		spin_unlock(&ci->i_ceph_lock);
 		dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
 		goto out;
 	}
@@ -2008,8 +2009,10 @@
 			mutex_lock(&session->s_mutex);
 			goto retry;
 		}
-		if (cap->session->s_state < CEPH_MDS_SESSION_OPEN)
+		if (cap->session->s_state < CEPH_MDS_SESSION_OPEN) {
+			spin_unlock(&ci->i_ceph_lock);
 			goto out;
+		}
 
 		flushing = __mark_caps_flushing(inode, session, true,
 						&flush_tid, &oldest_flush_tid);