stop using ioends for direct write completions

[Darrick J. Wong]

On Thu, Jan 28, 2016 at 11:02:55PM +0100, Christoph Hellwig wrote:
> On Thu, Jan 28, 2016 at 01:58:53PM -0800, Darrick J. Wong wrote:
> > Aw, snap, I knew I'd forgotten something.  Yep, we'll need that... I think
> > xfs_end_io_direct_write will have to sniff out the error status from "size"
> > and either remap or discard the CoW allocations as appropriate.
> 
> I'd rather fix the direct I/O code to give us that information directly
> (pun intended).  I'll add that to my short term todo list as it seems
> useful for the existing code as well.

Ok.

As for the generic/154... the code on github is sadly not very bisectable,
other than to say that until yesterday I was still tacking new code onto
the end of the patchset.

That said, I was seeing occasional hangs in generic/154 (I needed to roll
the transactions between key parts of wrapping up a CoW) and they seem to
have gone away, so it's possible that I've fixed it already.

--D