ceph: switch back to testing for NULL folio->private in ceph_dirty_folio

Willy requested that we change this back to warning on folio->private
being non-NULl. He's trying to kill off the PG_private flag, and so we'd
like to catch where it's non-NULL.

Add a VM_WARN_ON_FOLIO (since it doesn't exist yet) and change over to
using that instead of VM_BUG_ON_FOLIO along with testing the ->private
pointer.

[ xiubli: define VM_WARN_ON_FOLIO macro in case DEBUG_VM is disabled
  reported by kernel test robot <[email protected]> ]

Cc: Matthew Wilcox <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Xiubo Li <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>

0 files changed, 0 insertions, 0 deletions