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authorJens Axboe <axboe@kernel.dk>2017-10-25 12:35:02 -0600
committerJens Axboe <axboe@kernel.dk>2017-10-25 12:36:50 -0600
commit8ac0d9a81edf2ef4a2268b65b802a6b856dc77e6 (patch)
tree569a5e450d44b3f9eea6a5b0f6a65c1d28837ddd /block/elevator.c
parent2527d99789e248576ac8081530cd4fd88730f8c7 (diff)
downloadlinux-0-day-8ac0d9a81edf2ef4a2268b65b802a6b856dc77e6.tar.gz
elevator: allow name aliases
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. Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'block/elevator.c')
-rw-r--r--block/elevator.c23
1 files changed, 17 insertions, 6 deletions
diff --git a/block/elevator.c b/block/elevator.c
index 77856bf..7bda083 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;
}
@@ -1114,6 +1123,7 @@ ssize_t elv_iosched_show(struct request_queue *q, char *name)
struct elevator_queue *e = q->elevator;
struct elevator_type *elv = NULL;
struct elevator_type *__e;
+ bool uses_mq = q->mq_ops != NULL;
int len = 0;
if (!queue_is_rq_based(q))
@@ -1126,7 +1136,8 @@ 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 == uses_mq)) {
len += sprintf(name+len, "[%s] ", elv->elevator_name);
continue;
}