Re: [PATCH V6 11/30] block: implement bio_pages_all() via bio_for_each_segment_all()

[Christoph Hellwig]

On Thu, Jun 14, 2018 at 09:23:54AM +0800, Ming Lei wrote:
> On Wed, Jun 13, 2018 at 07:44:12AM -0700, Christoph Hellwig wrote:
> > Given that we have a single, dubious user of bio_pages_all I'd rather
> > see it as an opencoded bio_for_each_ loop in the caller.
> 
> Yeah, that is fine since there is only one user in btrfs.

And I suspect it really is checking for the wrong thing.  I don't
fully understand that code, but as far as I can tell it really
needs to know if there is more than a file system block of data in
the bio, and btrfs conflats pages with blocks.  But I'd need btrfs
folks to confirm this.