On Fri, Feb 12, 2021 at 10:45:32AM -0500, Mike Snitzer wrote: > On Mon, Nov 16, 2020 at 10:05 AM Christoph Hellwig <hch@xxxxxx> wrote: > > > > Use set_capacity_and_notify to set the size of both the disk and block > > device. This also gets the uevent notifications for the resize for free. > > > > Signed-off-by: Christoph Hellwig <hch@xxxxxx> > > Reviewed-by: Hannes Reinecke <hare@xxxxxxx> > > --- > > drivers/md/dm.c | 3 +-- > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > diff --git a/drivers/md/dm.c b/drivers/md/dm.c > > index c18fc25485186d..62ad44925e73ec 100644 > > --- a/drivers/md/dm.c > > +++ b/drivers/md/dm.c > > @@ -1971,8 +1971,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, > > if (size != dm_get_size(md)) > > memset(&md->geometry, 0, sizeof(md->geometry)); > > > > - set_capacity(md->disk, size); > > - bd_set_nr_sectors(md->bdev, size); > > + set_capacity_and_notify(md->disk, size); > > > > dm_table_event_callback(t, event_callback, md); > > > > Not yet pinned down _why_ DM is calling set_capacity_and_notify() with > a size of 0 but, when running various DM regression tests, I'm seeing > a lot of noise like: > > [ 689.240037] dm-2: detected capacity change from 2097152 to 0 > > Is this pr_info really useful? Should it be moved to below: if > (!capacity || !size) so that it only prints if a uevent is sent? In general I suspect such a size change might be interesting to users if it e.g. comes from a remote event. So I'd be curious why this happens with DM, and if we can detect some higher level gendisk state to supress it if it is indeed spurious.
