ceph: fix rare potential cap leak

If we grab new_cap, retake the lock, and find we already have a cap now
for the given mds, release new_cap.

Signed-off-by: Sage Weil <sage@newdream.net>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 2a5404c..591202b 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -569,7 +569,8 @@ retry:
                list_add_tail(&cap->session_caps, &session->s_caps);
                session->s_nr_caps++;
                spin_unlock(&session->s_cap_lock);
-       }
+       } else if (new_cap)
+               ceph_put_cap(mdsc, new_cap);
 
        if (!ci->i_snap_realm) {
                /*