[PATCH v2 1/3] Consolidate fallocate{64} implementations

[Christoph Hellwig]

On Mon, Oct 17, 2016 at 05:52:12PM +0200, Andreas Schwab wrote:
> The error is EOPNOTSUPP, virtio-blk apparently does not support
> fallocate (neither does nfs).

virtio-blk is a block driver, it's the file system that needs to
support it.  NFS 4.2 actually does support a subset of the fallocate
functionality, but the spec isn't finished yet and thus usually
not turned on by default.

That being said: EOPNOTSUPP is a common return value for fallocate
and should be expected at any time.