diff options
Diffstat (limited to 'block/elevator.c')
| -rw-r--r-- | block/elevator.c | 55 |
1 files changed, 34 insertions, 21 deletions
diff --git a/block/elevator.c b/block/elevator.c index 8768a367fdd..a0afdd317ce 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -121,16 +121,16 @@ static struct elevator_type *elevator_get(const char *name) return e; } -static int elevator_attach(request_queue_t *q, struct elevator_queue *eq) +static void *elevator_init_queue(request_queue_t *q, struct elevator_queue *eq) { - int ret = 0; + return eq->ops->elevator_init_fn(q, eq); +} +static void elevator_attach(request_queue_t *q, struct elevator_queue *eq, + void *data) +{ q->elevator = eq; - - if (eq->ops->elevator_init_fn) - ret = eq->ops->elevator_init_fn(q, eq); - - return ret; + eq->elevator_data = data; } static char chosen_elevator[16]; @@ -181,6 +181,7 @@ int elevator_init(request_queue_t *q, char *name) struct elevator_type *e = NULL; struct elevator_queue *eq; int ret = 0; + void *data; INIT_LIST_HEAD(&q->queue_head); q->last_merge = NULL; @@ -202,10 +203,13 @@ int elevator_init(request_queue_t *q, char *name) if (!eq) return -ENOMEM; - ret = elevator_attach(q, eq); - if (ret) + data = elevator_init_queue(q, eq); + if (!data) { kobject_put(&eq->kobj); + return -ENOMEM; + } + elevator_attach(q, eq, data); return ret; } @@ -722,13 +726,16 @@ int elv_register_queue(struct request_queue *q) return error; } +static void __elv_unregister_queue(elevator_t *e) +{ + kobject_uevent(&e->kobj, KOBJ_REMOVE); + kobject_del(&e->kobj); +} + void elv_unregister_queue(struct request_queue *q) { - if (q) { - elevator_t *e = q->elevator; - kobject_uevent(&e->kobj, KOBJ_REMOVE); - kobject_del(&e->kobj); - } + if (q) + __elv_unregister_queue(q->elevator); } int elv_register(struct elevator_type *e) @@ -780,6 +787,7 @@ EXPORT_SYMBOL_GPL(elv_unregister); static int elevator_switch(request_queue_t *q, struct elevator_type *new_e) { elevator_t *old_elevator, *e; + void *data; /* * Allocate new elevator @@ -788,6 +796,12 @@ static int elevator_switch(request_queue_t *q, struct elevator_type *new_e) if (!e) return 0; + data = elevator_init_queue(q, e); + if (!data) { + kobject_put(&e->kobj); + return 0; + } + /* * Turn on BYPASS and drain all requests w/ elevator private data */ @@ -806,19 +820,19 @@ static int elevator_switch(request_queue_t *q, struct elevator_type *new_e) elv_drain_elevator(q); } - spin_unlock_irq(q->queue_lock); - /* - * unregister old elevator data + * Remember old elevator. */ - elv_unregister_queue(q); old_elevator = q->elevator; /* * attach and start new elevator */ - if (elevator_attach(q, e)) - goto fail; + elevator_attach(q, e, data); + + spin_unlock_irq(q->queue_lock); + + __elv_unregister_queue(old_elevator); if (elv_register_queue(q)) goto fail_register; @@ -837,7 +851,6 @@ fail_register: */ elevator_exit(e); e = NULL; -fail: q->elevator = old_elevator; elv_register_queue(q); clear_bit(QUEUE_FLAG_ELVSWITCH, &q->queue_flags); |