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))) { len += sprintf(name+len, "[%s] ", elv->elevator_name); continue; } diff --git a/include/linux/elevator.h b/include/linux/elevator.h index 5bc8f8682a3e..6df8b14f1f6a 100644 --- a/include/linux/elevator.h +++ b/include/linux/elevator.h @@ -144,6 +144,7 @@ struct elevator_type size_t icq_align; /* ditto */ struct elv_fs_entry *elevator_attrs; char elevator_name[ELV_NAME_MAX]; + const char *elevator_alias; struct module *elevator_owner; bool uses_mq; #ifdef CONFIG_BLK_DEBUG_FS -- 2.7.4
