Pull ceph fixes from Ilya Dryomov:

 - a set of patches that fixes various corner cases in mount and umount
   code (Xiubo Li). This has to do with choosing an MDS, distinguishing
   between laggy and down MDSes and parsing the server path.

 - inode initialization fixes (Jeff Layton). The one included here
   mostly concerns things like open_by_handle() and there is another one
   that will come through Al.

 - copy_file_range() now uses the new copy-from2 op (Luis Henriques).
   The existing copy-from op turned out to be infeasible for generic
   filesystem use; we disable the copy offload if OSDs don't support
   copy-from2.

 - a patch to link "rbd" and "block" devices together in sysfs (Hannes
   Reinecke)

... and a smattering of cleanups from Xiubo, Jeff and Chengguang.

* tag 'ceph-for-5.6-rc1' of https://github.com/ceph/ceph-client: (25 commits)
  rbd: set the 'device' link in sysfs
  ceph: move net/ceph/ceph_fs.c to fs/ceph/util.c
  ceph: print name of xattr in __ceph_{get,set}xattr() douts
  ceph: print r_direct_hash in hex in __choose_mds() dout
  ceph: use copy-from2 op in copy_file_range
  ceph: close holes in structs ceph_mds_session and ceph_mds_request
  rbd: work around -Wuninitialized warning
  ceph: allocate the correct amount of extra bytes for the session features
  ceph: rename get_session and switch to use ceph_get_mds_session
  ceph: remove the extra slashes in the server path
  ceph: add possible_max_rank and make the code more readable
  ceph: print dentry offset in hex and fix xattr_version type
  ceph: only touch the caps which have the subset mask requested
  ceph: don't clear I_NEW until inode metadata is fully populated
  ceph: retry the same mds later after the new session is opened
  ceph: check availability of mds cluster on mount after wait timeout
  ceph: keep the session state until it is released
  ceph: add __send_request helper
  ceph: ensure we have a new cap before continuing in fill_inode
  ceph: drop unused ttl_from parameter from fill_inode
  ...