On Tue, Jul 30 2019 at 5:38pm -0400,
Dan Williams <[email protected]> wrote:
> On Tue, Jul 30, 2019 at 12:07 PM Mike Snitzer <[email protected]> wrote:
> >
> > I staged the fix (which I tweaked) here:
> > https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-5.3&id=95b9ebb78c4c733f8912a195fbd0bc19960e726e
>
> Thanks for picking this up Mike, but I'd prefer to just teach
> dax_synchronous() to return false if the passed in dax_dev is NULL.
> Thoughts?
I considered that too but I moved away from it because I'm so used to
the various block interfaces requiring the caller pass a non-NULL
pointer (e.g. request_queue):
$ grep -ri return drivers/md/dm-table.c | grep \&\&
drivers/md/dm-table.c: return dev->dax_dev && dax_synchronous(dev->dax_dev);
drivers/md/dm-table.c: return q && blk_queue_zoned_model(q) == *zoned_model;
drivers/md/dm-table.c: return q && blk_queue_zone_sectors(q) == *zone_sectors;
drivers/md/dm-table.c: return q && (q->queue_flags & flush);
drivers/md/dm-table.c: return q && blk_queue_nonrot(q);
drivers/md/dm-table.c: return q && !blk_queue_add_random(q);
drivers/md/dm-table.c: return q && !q->limits.max_write_same_sectors;
drivers/md/dm-table.c: return q && !q->limits.max_write_zeroes_sectors;
drivers/md/dm-table.c: return q && !blk_queue_discard(q);
drivers/md/dm-table.c: return q && !blk_queue_secure_erase(q);
drivers/md/dm-table.c: return q && bdi_cap_stable_pages_required(q->backing_dev_info);
I'm fine with however you'd like to skin this cat though.
Just let me know and I'll keep/drop this patch accordingly.
Thanks,
Mike
On Tue, Jul 30, 2019 at 3:01 PM Mike Snitzer <[email protected]> wrote:
>
> On Tue, Jul 30 2019 at 5:38pm -0400,
> Dan Williams <[email protected]> wrote:
>
> > On Tue, Jul 30, 2019 at 12:07 PM Mike Snitzer <[email protected]> wrote:
> > >
> > > I staged the fix (which I tweaked) here:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm.git/commit/?h=dm-5.3&id=95b9ebb78c4c733f8912a195fbd0bc19960e726e
> >
> > Thanks for picking this up Mike, but I'd prefer to just teach
> > dax_synchronous() to return false if the passed in dax_dev is NULL.
> > Thoughts?
>
> I considered that too but I moved away from it because I'm so used to
> the various block interfaces requiring the caller pass a non-NULL
> pointer (e.g. request_queue):
>
> $ grep -ri return drivers/md/dm-table.c | grep \&\&
> drivers/md/dm-table.c: return dev->dax_dev && dax_synchronous(dev->dax_dev);
> drivers/md/dm-table.c: return q && blk_queue_zoned_model(q) == *zoned_model;
> drivers/md/dm-table.c: return q && blk_queue_zone_sectors(q) == *zone_sectors;
> drivers/md/dm-table.c: return q && (q->queue_flags & flush);
> drivers/md/dm-table.c: return q && blk_queue_nonrot(q);
> drivers/md/dm-table.c: return q && !blk_queue_add_random(q);
> drivers/md/dm-table.c: return q && !q->limits.max_write_same_sectors;
> drivers/md/dm-table.c: return q && !q->limits.max_write_zeroes_sectors;
> drivers/md/dm-table.c: return q && !blk_queue_discard(q);
> drivers/md/dm-table.c: return q && !blk_queue_secure_erase(q);
> drivers/md/dm-table.c: return q && bdi_cap_stable_pages_required(q->backing_dev_info);
>
> I'm fine with however you'd like to skin this cat though.
>
> Just let me know and I'll keep/drop this patch accordingly.
Ok, since you've already got it queued, and there are no other
required "if (!dax_dev)" fixups go ahead with what you have.
Acked-by: Dan Williams <[email protected]>
I just reserve the right to go push it down a level if the kernel ever
grows more dax_synchronous() users that do that safety check.