Merge tag 'dm-3.19-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device...

Merge tag 'dm-3.19-fixes-3' of git://git./linux/kernel/git/device-mapper/linux-dm

Pull device mapper fixes from Mike Snitzer:
 "One stable fix for a dm-cache 3.19-rc6 regression and one stable fix
  for dm-thin:

   - fix DM cache metadata open/lookup error paths to properly use
     ERR_PTR and IS_ERR (fixes: 3.19-rc6 "stable" commit 9b1cc9f251)

   - fix DM thin-provisioning to disallow userspace from sending
     messages to the thin-pool if the pool is in READ_ONLY or FAIL mode
     since no metadata changes are allowed in these modes"

* tag 'dm-3.19-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm thin: don't allow messages to be sent to a pool target in READ_ONLY or FAIL mode
  dm cache: fix missing ERR_PTR returns and handling