BugLink: https://bugs.launchpad.net/bugs/1840081

commit d6e47819 upstream.

ceph_d_revalidate(, LOOKUP_RCU) may call __ceph_caps_issued_mask()
on a freeing inode.
Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>