Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...

Pull Ceph fix from Sage Weil:
 "It's a simple fix for a hard to hit race, but low-risk and clearly
  correct"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
  rbd: do a safe list traversal in rbd_img_request_submit()