#include <asm/uaccess.h>
-static spinlock_t elv_list_lock = SPIN_LOCK_UNLOCKED;
-static LIST_HEAD(elv_list);
-
/*
* can we safely merge with this request?
*/
return 0;
}
-EXPORT_SYMBOL(elv_rq_merge_ok);
inline int elv_try_merge(struct request *__rq, struct bio *bio)
{
return ret;
}
-EXPORT_SYMBOL(elv_try_merge);
inline int elv_try_last_merge(request_queue_t *q, struct bio *bio)
{
return ELEVATOR_NO_MERGE;
}
-EXPORT_SYMBOL(elv_try_last_merge);
-
-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;
-
- __e = list_entry(entry, struct elevator_type, list);
-
- if (!strcmp(__e->elevator_name, name)) {
- e = __e;
- break;
- }
- }
- spin_unlock_irq(&elv_list_lock);
-
- return e;
-}
-
-static void elevator_put(struct elevator_type *e)
-{
- module_put(e->elevator_owner);
-}
-
-static struct elevator_type *elevator_get(const char *name)
-{
- struct elevator_type *e = elevator_find(name);
-
- if (!e)
- return NULL;
- if (!try_module_get(e->elevator_owner))
- return NULL;
- return e;
-}
-
-static int elevator_attach(request_queue_t *q, struct elevator_type *e,
- struct elevator_queue *eq)
+/*
+ * general block -> elevator interface starts here
+ */
+int elevator_init(request_queue_t *q, elevator_t *type)
{
- int ret = 0;
+ elevator_t *e = &q->elevator;
- memset(eq, 0, sizeof(*eq));
- eq->ops = &e->ops;
- eq->elevator_type = e;
+ memcpy(e, type, sizeof(*e));
INIT_LIST_HEAD(&q->queue_head);
q->last_merge = NULL;
- q->elevator = eq;
-
- if (eq->ops->elevator_init_fn)
- ret = eq->ops->elevator_init_fn(q, eq);
-
- return ret;
-}
-static char chosen_elevator[16];
+ if (e->elevator_init_fn)
+ return e->elevator_init_fn(q, e);
-static void elevator_setup_default(void)
-{
- /*
- * check if default is set and exists
- */
- if (chosen_elevator[0] && elevator_find(chosen_elevator))
- return;
-
-#if defined(CONFIG_IOSCHED_AS)
- strcpy(chosen_elevator, "anticipatory");
-#elif defined(CONFIG_IOSCHED_DEADLINE)
- strcpy(chosen_elevator, "deadline");
-#elif defined(CONFIG_IOSCHED_CFQ)
- strcpy(chosen_elevator, "cfq");
-#elif defined(CONFIG_IOSCHED_NOOP)
- strcpy(chosen_elevator, "noop");
-#else
-#error "You must build at least 1 IO scheduler into the kernel"
-#endif
- printk(KERN_INFO "elevator: using %s as default io scheduler\n",
- chosen_elevator);
-}
-
-static int __init elevator_setup(char *str)
-{
- strncpy(chosen_elevator, str, sizeof(chosen_elevator) - 1);
return 0;
}
-__setup("elevator=", elevator_setup);
-
-int elevator_init(request_queue_t *q, char *name)
+void elevator_exit(request_queue_t *q)
{
- struct elevator_type *e = NULL;
- struct elevator_queue *eq;
- int ret = 0;
-
- elevator_setup_default();
-
- if (!name)
- name = chosen_elevator;
-
- e = elevator_get(name);
- if (!e)
- return -EINVAL;
-
- eq = kmalloc(sizeof(struct elevator_queue), GFP_KERNEL);
- if (!eq) {
- elevator_put(e->elevator_type);
- return -ENOMEM;
- }
-
- ret = elevator_attach(q, e, eq);
- if (ret) {
- kfree(eq);
- elevator_put(e->elevator_type);
- }
+ elevator_t *e = &q->elevator;
- return ret;
-}
-
-void elevator_exit(elevator_t *e)
-{
- if (e->ops->elevator_exit_fn)
- e->ops->elevator_exit_fn(e);
-
- elevator_put(e->elevator_type);
- e->elevator_type = NULL;
- kfree(e);
+ if (e->elevator_exit_fn)
+ e->elevator_exit_fn(q, e);
}
int elevator_global_init(void)
int elv_merge(request_queue_t *q, struct request **req, struct bio *bio)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_merge_fn)
- return e->ops->elevator_merge_fn(q, req, bio);
+ if (e->elevator_merge_fn)
+ return e->elevator_merge_fn(q, req, bio);
return ELEVATOR_NO_MERGE;
}
void elv_merged_request(request_queue_t *q, struct request *rq)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_merged_fn)
- e->ops->elevator_merged_fn(q, rq);
+ if (e->elevator_merged_fn)
+ e->elevator_merged_fn(q, rq);
}
void elv_merge_requests(request_queue_t *q, struct request *rq,
struct request *next)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
if (q->last_merge == next)
q->last_merge = NULL;
- if (e->ops->elevator_merge_req_fn)
- e->ops->elevator_merge_req_fn(q, rq, next);
+ if (e->elevator_merge_req_fn)
+ e->elevator_merge_req_fn(q, rq, next);
}
void elv_requeue_request(request_queue_t *q, struct request *rq)
* if iosched has an explicit requeue hook, then use that. otherwise
* just put the request at the front of the queue
*/
- if (q->elevator->ops->elevator_requeue_req_fn)
- q->elevator->ops->elevator_requeue_req_fn(q, rq);
+ if (q->elevator.elevator_requeue_req_fn)
+ q->elevator.elevator_requeue_req_fn(q, rq);
else
__elv_add_request(q, rq, ELEVATOR_INSERT_FRONT, 0);
}
blk_plug_device(q);
rq->q = q;
+ q->elevator.elevator_add_req_fn(q, rq, where);
- if (!test_bit(QUEUE_FLAG_DRAIN, &q->queue_flags)) {
- q->elevator->ops->elevator_add_req_fn(q, rq, where);
+ if (blk_queue_plugged(q)) {
+ int nrq = q->rq.count[READ] + q->rq.count[WRITE] - q->in_flight;
- if (blk_queue_plugged(q)) {
- int nrq = q->rq.count[READ] + q->rq.count[WRITE]
- - q->in_flight;
+ if (nrq == q->unplug_thresh)
+ __generic_unplug_device(q);
+ }
- if (nrq == q->unplug_thresh)
- __generic_unplug_device(q);
- }
- } else
- /*
- * if drain is set, store the request "locally". when the drain
- * is finished, the requests will be handed ordered to the io
- * scheduler
- */
- list_add_tail(&rq->queuelist, &q->drain_list);
}
void elv_add_request(request_queue_t *q, struct request *rq, int where,
static inline struct request *__elv_next_request(request_queue_t *q)
{
- return q->elevator->ops->elevator_next_req_fn(q);
+ return q->elevator.elevator_next_req_fn(q);
}
struct request *elv_next_request(request_queue_t *q)
end_that_request_chunk(rq, 0, nr_bytes);
end_that_request_last(rq);
} else {
- printk(KERN_ERR "%s: bad return=%d\n", __FUNCTION__,
- ret);
+ printk("%s: bad return=%d\n", __FUNCTION__, ret);
break;
}
}
void elv_remove_request(request_queue_t *q, struct request *rq)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
/*
* the time frame between a request being removed from the lists
if (rq == q->last_merge)
q->last_merge = NULL;
- if (e->ops->elevator_remove_req_fn)
- e->ops->elevator_remove_req_fn(q, rq);
+ if (e->elevator_remove_req_fn)
+ e->elevator_remove_req_fn(q, rq);
}
int elv_queue_empty(request_queue_t *q)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_queue_empty_fn)
- return e->ops->elevator_queue_empty_fn(q);
+ if (e->elevator_queue_empty_fn)
+ return e->elevator_queue_empty_fn(q);
return list_empty(&q->queue_head);
}
{
struct list_head *next;
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_latter_req_fn)
- return e->ops->elevator_latter_req_fn(q, rq);
+ if (e->elevator_latter_req_fn)
+ return e->elevator_latter_req_fn(q, rq);
next = rq->queuelist.next;
if (next != &q->queue_head && next != &rq->queuelist)
{
struct list_head *prev;
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_former_req_fn)
- return e->ops->elevator_former_req_fn(q, rq);
+ if (e->elevator_former_req_fn)
+ return e->elevator_former_req_fn(q, rq);
prev = rq->queuelist.prev;
if (prev != &q->queue_head && prev != &rq->queuelist)
int elv_set_request(request_queue_t *q, struct request *rq, int gfp_mask)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_set_req_fn)
- return e->ops->elevator_set_req_fn(q, rq, gfp_mask);
+ if (e->elevator_set_req_fn)
+ return e->elevator_set_req_fn(q, rq, gfp_mask);
rq->elevator_private = NULL;
return 0;
void elv_put_request(request_queue_t *q, struct request *rq)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_put_req_fn)
- e->ops->elevator_put_req_fn(q, rq);
+ if (e->elevator_put_req_fn)
+ e->elevator_put_req_fn(q, rq);
+}
+
+void elv_set_congested(request_queue_t *q)
+{
+ elevator_t *e = &q->elevator;
+
+ if (e->elevator_set_congested_fn)
+ e->elevator_set_congested_fn(q);
}
int elv_may_queue(request_queue_t *q, int rw)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
- if (e->ops->elevator_may_queue_fn)
- return e->ops->elevator_may_queue_fn(q, rw);
+ if (e->elevator_may_queue_fn)
+ return e->elevator_may_queue_fn(q, rw);
- return ELV_MQUEUE_MAY;
+ return 1;
}
void elv_completed_request(request_queue_t *q, struct request *rq)
{
- elevator_t *e = q->elevator;
+ elevator_t *e = &q->elevator;
/*
* request is released from the driver, io must be done
if (blk_account_rq(rq))
q->in_flight--;
- if (e->ops->elevator_completed_req_fn)
- e->ops->elevator_completed_req_fn(q, rq);
+ if (e->elevator_completed_req_fn)
+ e->elevator_completed_req_fn(q, rq);
}
int elv_register_queue(struct request_queue *q)
{
- elevator_t *e = q->elevator;
+ elevator_t *e;
+
+ e = &q->elevator;
e->kobj.parent = kobject_get(&q->kobj);
if (!e->kobj.parent)
return -EBUSY;
snprintf(e->kobj.name, KOBJ_NAME_LEN, "%s", "iosched");
- e->kobj.ktype = e->elevator_type->elevator_ktype;
+ e->kobj.ktype = e->elevator_ktype;
return kobject_register(&e->kobj);
}
void elv_unregister_queue(struct request_queue *q)
{
if (q) {
- elevator_t *e = q->elevator;
+ elevator_t * e = &q->elevator;
kobject_unregister(&e->kobj);
kobject_put(&q->kobj);
}
}
-int elv_register(struct elevator_type *e)
-{
- 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);
-
- printk(KERN_INFO "io scheduler %s registered\n", e->elevator_name);
- return 0;
-}
-EXPORT_SYMBOL_GPL(elv_register);
-
-void elv_unregister(struct elevator_type *e)
-{
- spin_lock_irq(&elv_list_lock);
- list_del_init(&e->list);
- spin_unlock_irq(&elv_list_lock);
-}
-EXPORT_SYMBOL_GPL(elv_unregister);
-
-/*
- * switch to new_e io scheduler. be careful not to introduce deadlocks -
- * we don't free the old io scheduler, before we have allocated what we
- * need for the new one. this way we have a chance of going back to the old
- * one, if the new one fails init for some reason. we also do an intermediate
- * switch to noop to ensure safety with stack-allocated requests, since they
- * don't originate from the block layer allocator. noop is safe here, because
- * it never needs to touch the elevator itself for completion events. DRAIN
- * flags will make sure we don't touch it for additions either.
- */
-static void elevator_switch(request_queue_t *q, struct elevator_type *new_e)
-{
- elevator_t *e = kmalloc(sizeof(elevator_t), GFP_KERNEL);
- struct elevator_type *noop_elevator = NULL;
- elevator_t *old_elevator;
-
- if (!e)
- goto error;
-
- /*
- * first step, drain requests from the block freelist
- */
- blk_wait_queue_drained(q, 0);
-
- /*
- * unregister old elevator data
- */
- elv_unregister_queue(q);
- old_elevator = q->elevator;
-
- /*
- * next step, switch to noop since it uses no private rq structures
- * and doesn't allocate any memory for anything. then wait for any
- * non-fs requests in-flight
- */
- noop_elevator = elevator_get("noop");
- spin_lock_irq(q->queue_lock);
- elevator_attach(q, noop_elevator, e);
- spin_unlock_irq(q->queue_lock);
-
- blk_wait_queue_drained(q, 1);
-
- /*
- * attach and start new elevator
- */
- if (elevator_attach(q, new_e, e))
- goto fail;
-
- if (elv_register_queue(q))
- goto fail_register;
-
- /*
- * finally exit old elevator and start queue again
- */
- elevator_exit(old_elevator);
- blk_finish_queue_drain(q);
- elevator_put(noop_elevator);
- return;
-
-fail_register:
- /*
- * switch failed, exit the new io scheduler and reattach the old
- * one again (along with re-adding the sysfs dir)
- */
- elevator_exit(e);
-fail:
- q->elevator = old_elevator;
- elv_register_queue(q);
- blk_finish_queue_drain(q);
-error:
- if (noop_elevator)
- elevator_put(noop_elevator);
- elevator_put(new_e);
- printk(KERN_ERR "elevator: switch to %s failed\n",new_e->elevator_name);
-}
-
-ssize_t elv_iosched_store(request_queue_t *q, const char *name, size_t count)
-{
- char elevator_name[ELV_NAME_MAX];
- struct elevator_type *e;
-
- memset(elevator_name, 0, sizeof(elevator_name));
- strncpy(elevator_name, name, sizeof(elevator_name));
-
- if (elevator_name[strlen(elevator_name) - 1] == '\n')
- elevator_name[strlen(elevator_name) - 1] = '\0';
-
- e = elevator_get(elevator_name);
- if (!e) {
- printk(KERN_ERR "elevator: type %s not found\n", elevator_name);
- return -EINVAL;
- }
-
- if (!strcmp(elevator_name, q->elevator->elevator_type->elevator_name))
- return count;
-
- elevator_switch(q, e);
- return count;
-}
-
-ssize_t elv_iosched_show(request_queue_t *q, char *name)
-{
- elevator_t *e = q->elevator;
- struct elevator_type *elv = e->elevator_type;
- struct list_head *entry;
- int len = 0;
-
- spin_lock_irq(q->queue_lock);
- list_for_each(entry, &elv_list) {
- struct elevator_type *__e;
-
- __e = list_entry(entry, struct elevator_type, list);
- if (!strcmp(elv->elevator_name, __e->elevator_name))
- len += sprintf(name+len, "[%s] ", elv->elevator_name);
- else
- len += sprintf(name+len, "%s ", __e->elevator_name);
- }
- spin_unlock_irq(q->queue_lock);
-
- len += sprintf(len+name, "\n");
- return len;
-}
-
module_init(elevator_global_init);
EXPORT_SYMBOL(elv_add_request);
git://git.onelab.eu / linux-2.6.git / blobdiff