Merge tag 'afs-next-20190915' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowel...

Pull AFS updates from David Howells:
 "Here's a set of patches for AFS. The first three are trivial, deleting
  unused symbols and rolling out a wrapper function.

  The fourth and fifth patches make use of the previously added RCU-safe
  request_key facility to allow afs_permission() and afs_d_revalidate()
  to attempt to operate without dropping out of RCU-mode pathwalk. Under
  certain conditions, such as conflict with another client, we still
  have to drop out anyway, take a lock and consult the server"

* tag 'afs-next-20190915' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  afs: Support RCU pathwalk
  afs: Provide an RCU-capable key lookup
  afs: Use afs_extract_discard() rather than iov_iter_discard()
  afs: remove unused variable 'afs_zero_fid'
  afs: remove unused variable 'afs_voltypes'