From: Jeff Layton <jlayton@redhat.com>
Date: Thu, 19 Oct 2017 12:52:58 +0000 (-0400)
Subject: ceph: unlock dangling spinlock in try_flush_caps()
X-Git-Tag: v3.18.79~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=55d4aa12af57ea7782f0c8bbc3b01e44673b05ba;p=thirdparty%2Fkernel%2Fstable.git

ceph: unlock dangling spinlock in try_flush_caps()

commit 6c2838fbdedb9b72a81c931d49e56b229b6cdbca upstream.

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.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index cefca661464b9..45692e8a93971 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1748,6 +1748,7 @@ static int try_flush_caps(struct inode *inode, unsigned *flush_tid)
 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;
 	}
@@ -1765,8 +1766,10 @@ retry:
 			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);