Pull Ceph updates from Ilya Dryomov:
"The big ticket item here is support for rbd exclusive-lock feature,
with maintenance operations offloaded to userspace (Douglas Fuller,
Mike Christie and myself). Another block device bullet is a series
fixing up layering error paths (myself).
On the filesystem side, we've got patches that improve our handling of
buffered vs dio write races (Neil Brown) and a few assorted fixes from
Zheng. Also included a couple of random cleanups and a minor CRUSH
update"
* tag 'ceph-for-4.9-rc1' of git://github.com/ceph/ceph-client: (39 commits)
crush: remove redundant local variable
crush: don't normalize input of crush_ln iteratively
libceph: ceph_build_auth() doesn't need ceph_auth_build_hello()
libceph: use CEPH_AUTH_UNKNOWN in ceph_auth_build_hello()
ceph: fix description for rsize and rasize mount options
rbd: use kmalloc_array() in rbd_header_from_disk()
ceph: use list_move instead of list_del/list_add
ceph: handle CEPH_SESSION_REJECT message
ceph: avoid accessing / when mounting a subpath
ceph: fix mandatory flock check
ceph: remove warning when ceph_releasepage() is called on dirty page
ceph: ignore error from invalidate_inode_pages2_range() in direct write
ceph: fix error handling of start_read()
rbd: add rbd_obj_request_error() helper
rbd: img_data requests don't own their page array
rbd: don't call rbd_osd_req_format_read() for !img_data requests
rbd: rework rbd_img_obj_exists_submit() error paths
rbd: don't crash or leak on errors in rbd_img_obj_parent_read_full_callback()
rbd: move bumping img_request refcount into rbd_obj_request_submit()
rbd: mark the original request as done if stat request fails
...