Re: [PATCH v2 2/2] xfs: use sync buffer I/O for sync delwri queue submission

[Christoph Hellwig <hch@infradead.org>]

On Fri, Jun 15, 2018 at 08:39:56AM -0400, Brian Foster wrote:
> Ok, codewise I don't have much of a preference, but I don't think it's
> worth redoing the regression testing and lowmem testing and whatnot just
> to change how the guts are refactored here. What's the endgame?

Avoid the nasty duplication as much as possible.  I think your patch
already goes a long way towards that, but I'd rather go all the way.

> I came
> up with the following on top of patch 2. Compile tested only, and I can
> refold the _common() helper back into the caller and invert the
> nowait logic or whatnot..

Mostly looks fine, except that it seems pointless to have
__xfs_buf_submit_common around instead of merging it into the only
caller.

> +	if (!(bp->b_flags & XBF_ASYNC) && !sync_nowait)

Also I'd rather pass in a

	'bool wait' parameter.

xfs_buf_submit() would set it based on XBF_ASYNC, and the delwri
code would just set it to false explicitly.