Merge git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client

* git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  libceph: Create a new key type "ceph".
  libceph: Get secret from the kernel keys api when mounting with key=NAME.
  ceph: Move secret key parsing earlier.
  libceph: fix null dereference when unregistering linger requests
  ceph: unlock on error in ceph_osdc_start_request()
  ceph: fix possible NULL pointer dereference
  ceph: flush msgr_wq during mds_client shutdown