block: Expose stacked device queues in sysfs

Currently stacking devices do not have a queue directory in sysfs.
However, many of the I/O characteristics like sector size, maximum
request size, etc. are queue properties.

This patch enables the queue directory for MD/DM devices.  The elevator
code has been modified to deal with queues that do not have an I/O
scheduler.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This commit is contained in:
Martin K. Petersen 2009-05-22 17:17:52 -04:00 committed by Jens Axboe
parent 025146e13b
commit cd43e26f07
2 changed files with 15 additions and 4 deletions

View File

@ -395,9 +395,6 @@ int blk_register_queue(struct gendisk *disk)
if (WARN_ON(!q))
return -ENXIO;
if (!q->request_fn)
return 0;
ret = kobject_add(&q->kobj, kobject_get(&disk_to_dev(disk)->kobj),
"%s", "queue");
if (ret < 0)
@ -405,6 +402,9 @@ int blk_register_queue(struct gendisk *disk)
kobject_uevent(&q->kobj, KOBJ_ADD);
if (!q->request_fn)
return 0;
ret = elv_register_queue(q);
if (ret) {
kobject_uevent(&q->kobj, KOBJ_REMOVE);

View File

@ -575,6 +575,9 @@ void elv_drain_elevator(struct request_queue *q)
*/
void elv_quiesce_start(struct request_queue *q)
{
if (!q->elevator)
return;
queue_flag_set(QUEUE_FLAG_ELVSWITCH, q);
/*
@ -1050,6 +1053,9 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
char elevator_name[ELV_NAME_MAX];
struct elevator_type *e;
if (!q->elevator)
return count;
strlcpy(elevator_name, name, sizeof(elevator_name));
strstrip(elevator_name);
@ -1073,10 +1079,15 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
ssize_t elv_iosched_show(struct request_queue *q, char *name)
{
struct elevator_queue *e = q->elevator;
struct elevator_type *elv = e->elevator_type;
struct elevator_type *elv;
struct elevator_type *__e;
int len = 0;
if (!q->elevator)
return sprintf(name, "none\n");
elv = e->elevator_type;
spin_lock(&elv_list_lock);
list_for_each_entry(__e, &elv_list, list) {
if (!strcmp(elv->elevator_name, __e->elevator_name))