On Wed, Oct 25, 2017 at 12:04:46PM -0600, Jens Axboe wrote: > Since we now lookup elevator types with the appropriate multiqueue > capability, allow schedulers to register with an alias alongside > the real name. This is in preparation for allowing 'mq-deadline' > to register an alias of 'deadline' as well. > > Signed-off-by: Jens Axboe <[email protected]> > --- > block/elevator.c | 22 ++++++++++++++++------ > include/linux/elevator.h | 1 + > 2 files changed, 17 insertions(+), 6 deletions(-) > > diff --git a/block/elevator.c b/block/elevator.c > index b70e69f795db..dc0432e12ecf 100644 > --- a/block/elevator.c > +++ b/block/elevator.c > @@ -83,6 +83,16 @@ bool elv_bio_merge_ok(struct request *rq, struct bio *bio) > } > EXPORT_SYMBOL(elv_bio_merge_ok); > > +static bool elevator_match(const struct elevator_type *e, const char *name) > +{ > + if (!strcmp(e->elevator_name, name)) > + return true; > + if (e->elevator_alias && !strcmp(e->elevator_alias, name)) > + return true; > + > + return false; > +} > + > /* > * Return scheduler with name 'name' and with matching 'mq capability > */ > @@ -91,7 +101,7 @@ 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) && !(mq ^ e->uses_mq)) > + if (elevator_match(e, name) && !(mq ^ e->uses_mq)) > return e; > } > > @@ -922,9 +932,9 @@ int elv_register(struct elevator_type *e) > spin_unlock(&elv_list_lock); > > /* print pretty message */ > - if (!strcmp(e->elevator_name, chosen_elevator) || > + if (elevator_match(e, chosen_elevator) || > (!*chosen_elevator && > - !strcmp(e->elevator_name, CONFIG_DEFAULT_IOSCHED))) > + elevator_match(e, CONFIG_DEFAULT_IOSCHED))) > def = " (default)"; > > printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name, > @@ -1077,8 +1087,7 @@ static int __elevator_change(struct request_queue *q, > const char *name) > if (!e) > return -EINVAL; > > - if (q->elevator && > - !strcmp(elevator_name, q->elevator->type->elevator_name)) { > + if (q->elevator && elevator_match(q->elevator->type, elevator_name)) { > elevator_put(e); > return 0; > } > @@ -1126,7 +1135,8 @@ ssize_t elv_iosched_show(struct request_queue *q, char > *name) > > spin_lock(&elv_list_lock); > list_for_each_entry(__e, &elv_list, list) { > - if (elv && !strcmp(elv->elevator_name, __e->elevator_name)) { > + if (elv && elevator_match(elv, __e->elevator_name) && > + !(__e->uses_mq ^ (q->mq_ops != NULL))) {
Same thing here, (__e->uses_mq == (q->mq_ops != NULL)). Still confusing but less so. Otherwise Reviewed-by: Omar Sandoval <[email protected]>
