On Wed, Oct 25, 2017 at 12:04:45PM -0600, Jens Axboe wrote: > If an IO scheduler is selected via elevator= and it doesn't match > the driver in question wrt blk-mq support, then we fail to boot. > > The elevator= parameter is deprecated and only supported for > non-mq devices. Augment the elevator lookup API so that we > pass in if we're looking for an mq capable scheduler or not, > so that we only ever return a valid type for the queue in > question. > > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=196695 > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > --- > block/elevator.c | 44 +++++++++++++++++++++----------------------- > 1 file changed, 21 insertions(+), 23 deletions(-) > > diff --git a/block/elevator.c b/block/elevator.c > index 7ae50eb2732b..b70e69f795db 100644 > --- a/block/elevator.c > +++ b/block/elevator.c > @@ -83,12 +83,15 @@ bool elv_bio_merge_ok(struct request *rq, struct bio *bio) > } > EXPORT_SYMBOL(elv_bio_merge_ok); > > -static struct elevator_type *elevator_find(const char *name) > +/* > + * Return scheduler with name 'name' and with matching 'mq capability > + */ > +static struct elevator_type *elevator_find(const char *name, bool mq) > { > struct elevator_type *e; > > list_for_each_entry(e, &elv_list, list) { > - if (!strcmp(e->elevator_name, name)) > + if (!strcmp(e->elevator_name, name) && !(mq ^ e->uses_mq)) How about just (mq == e->uses_mq)? Besides that, Reviewed-by: Omar Sandoval <osandov@xxxxxx> > return e; > } >
