On Fri, Mar 02, 2018 at 11:20:31PM +0100, Christoph Hellwig wrote:
> > --- a/fs/xfs/xfs_file.c
> > +++ b/fs/xfs/xfs_file.c
> > @@ -732,6 +732,11 @@ xfs_file_write_iter(
> > ret = xfs_file_dio_aio_write(iocb, from);
> > if (ret == -EREMCHG)
> > goto buffered;
> > + /*
> > + * Direct IO handles sync type writes internally on I/O
> > + * completion.
> > + */
> > + return ret;
> > } else {
> > buffered:
> > ret = xfs_file_buffered_aio_write(iocb, from);
>
> The else is not needed and you can now have a much more sensible
> code flow here:
>
> ret = xfs_file_dio_aio_write(iocb, from);
> if (ret != -EREMCHG))
> return ret;
> }
>
> ret = xfs_file_buffered_aio_write(iocb, from);
Actually a little more complicated due to the DAX case, and the fact
that both your original and this new version miss the XFS_STATS_ADD
call. But you get the idea. While we're at it we should probably
also skil the generic_write_sync call for DAX pure overwrites while
we're at it.
