Re: [PATCH 4/6] iomap: advance the iter directly on buffered writes

[Brian Foster <bfoster@redhat.com>]

On Wed, Jan 08, 2025 at 11:10:48PM -0800, Christoph Hellwig wrote:
> On Fri, Dec 13, 2024 at 09:36:08AM -0500, Brian Foster wrote:
> > +		loff_t pos = iter->pos;
> > +		loff_t length = iomap_length(iter);
> 
> AFAICS we could just do away with these local variables as they should
> never get out of sync with the values in the iter.  If so I'd love to see
> that one.  If they can get out of sync and we actually need them, that
> would warrant a comment.
> 
> Otherwise this looks good to me, and the same applies to the next two
> patches.
> 

Hmm.. they should not get out of sync, but that wasn't necessarily the
point here. For one, this is trying to be incremental and highlight the
actual logic changes, but also I didn't want to just go and replace
every usage of pos with iter->pos when it only needs to be read at a
certain point.

This might be a little more clear after the (non-squashed) fbatch
patches which move where pos is sampled (to handle that it can change at
that point) and drop some of the pos function params, but if we still
want to clean that up at the end I'd rather do it as a standalone patch
at that point.

All that said, length is only used for the bytes check so I can probably
kill that one off here.

Brian