ceph: unlock dangling spinlock in try_flush_caps()

BugLink: http://bugs.launchpad.net/bugs/1731961
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>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 7007ae2a5ad2ec4e506ca8216c2fd5253ee35bca..388f0267cec59e0d45784df7599c7df9a6ef3484 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -1985,6 +1985,7 @@ static int try_flush_caps(struct inode *inode, u64 *ptid)
 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;
        }
@@ -2002,8 +2003,10 @@ 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, true,
                                                &flush_tid, &oldest_flush_tid);