diff options
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/elevator.c | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/drivers/block/elevator.c b/drivers/block/elevator.c index 98f0126a2deb..4144f30d82a9 100644 --- a/drivers/block/elevator.c +++ b/drivers/block/elevator.c @@ -97,7 +97,6 @@ static struct elevator_type *elevator_find(const char *name) struct elevator_type *e = NULL; struct list_head *entry; - spin_lock_irq(&elv_list_lock); list_for_each(entry, &elv_list) { struct elevator_type *__e; @@ -108,7 +107,6 @@ static struct elevator_type *elevator_find(const char *name) break; } } - spin_unlock_irq(&elv_list_lock); return e; } @@ -120,12 +118,15 @@ static void elevator_put(struct elevator_type *e) static struct elevator_type *elevator_get(const char *name) { - struct elevator_type *e = elevator_find(name); + struct elevator_type *e; - if (!e) - return NULL; - if (!try_module_get(e->elevator_owner)) - return NULL; + spin_lock_irq(&elv_list_lock); + + e = elevator_find(name); + if (e && !try_module_get(e->elevator_owner)) + e = NULL; + + spin_unlock_irq(&elv_list_lock); return e; } @@ -153,11 +154,15 @@ static char chosen_elevator[16]; static void elevator_setup_default(void) { + struct elevator_type *e; + /* * check if default is set and exists */ - if (chosen_elevator[0] && elevator_find(chosen_elevator)) + if (chosen_elevator[0] && (e = elevator_get(chosen_elevator))) { + elevator_put(e); return; + } #if defined(CONFIG_IOSCHED_AS) strcpy(chosen_elevator, "anticipatory"); @@ -555,10 +560,9 @@ void elv_unregister_queue(struct request_queue *q) int elv_register(struct elevator_type *e) { + spin_lock_irq(&elv_list_lock); if (elevator_find(e->elevator_name)) BUG(); - - spin_lock_irq(&elv_list_lock); list_add_tail(&e->list, &elv_list); spin_unlock_irq(&elv_list_lock); |