Pull ceph updates from Sage Weil:
"The bulk of this pull is a series from Alex that refactors and cleans
up the RBD code to lay the groundwork for supporting the new image
format and evolving feature set. There are also some cleanups in
libceph, and for ceph there's fixed validation of file striping
layouts and a bugfix in the code handling a shrinking MDS cluster."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (71 commits)
ceph: avoid 32-bit page index overflow
ceph: return EIO on invalid layout on GET_DATALOC ioctl
rbd: BUG on invalid layout
ceph: propagate layout error on osd request creation
libceph: check for invalid mapping
ceph: convert to use le32_add_cpu()
ceph: Fix oops when handling mdsmap that decreases max_mds
rbd: update remaining header fields for v2
rbd: get snapshot name for a v2 image
rbd: get the snapshot context for a v2 image
rbd: get image features for a v2 image
rbd: get the object prefix for a v2 rbd image
rbd: add code to get the size of a v2 rbd image
rbd: lay out header probe infrastructure
rbd: encapsulate code that gets snapshot info
rbd: add an rbd features field
rbd: don't use index in __rbd_add_snap_dev()
rbd: kill create_snap sysfs entry
rbd: define rbd_dev_image_id()
rbd: define some new format constants
...