- Don't allocate cow blocks when we're zeroing file data
* tag 'xfs-4.16-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: don't block on the ilock for RWF_NOWAIT
xfs: don't start out with the exclusive ilock for direct I/O
xfs: don't allocate COW blocks for zeroing holes or unwritten extents