On Thu, Sep 17, 2020 at 11:25:24AM +0200, Jan Kara wrote: > On Thu 10-09-20 16:48:30, Christoph Hellwig wrote: > > The BDI_CAP_STABLE_WRITES is one of the few bits of information in the > > backing_dev_info shared between the block drivers and the writeback code. > > To help untangling the dependency replace it with a queue flag and a > > superblock flag derived from it. This also helps with the case of e.g. > > a file system requiring stable writes due to its own checksumming, but > > not forcing it on other users of the block device like the swap code. > > > > One downside is that we can't support the stable_pages_required bdi > > attribute in sysfs anymore. It is replaced with a queue attribute, that > > can also be made writable for easier testing. > ^^^^^^^^^^^^^^^^ > is also made > > For a while I was confused thinking that the new attribute is not writeable > but when I checked the code I saw that it is. > > Not supporting stable_pages_required attribute is not nice but probably it > isn't widely used. Maybe the deprecation message can even mention to use > the queue attribute? Otherwise the patch looks good to me so feel free to > add: > > Reviewed-by: Jan Kara <jack@xxxxxxx> Thanks. I've fixed the commit log and changed the warning to: dev_warn_once(dev, "the stable_pages_required attribute has been removed. Use the stable_writes queue attribute instead.\n");