Pull more vfs updates from Al Viro:
 "Embarrassing braino fix + pipe page accounting + fixing an eyesore in
  find_filesystem() (checking that s1 is equal to prefix of s2 of given
  length can be done in many ways, but "compare strlen(s1) with length
  and then do strncmp()" is not a good one...)"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [regression] fix braino in fs/dlm/user.c
  pipe: limit the per-user amount of pages allocated in pipes
  find_filesystem(): simplify comparison