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.