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Diffstat (limited to 'block/elevator.c')
-rw-r--r--block/elevator.c477
1 files changed, 33 insertions, 444 deletions
diff --git a/block/elevator.c b/block/elevator.c
index 8fdcd64ae12e..f05e90d4e695 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -61,10 +61,8 @@ static int elv_iosched_allow_bio_merge(struct request *rq, struct bio *bio)
struct request_queue *q = rq->q;
struct elevator_queue *e = q->elevator;
- if (e->uses_mq && e->type->ops.mq.allow_merge)
- return e->type->ops.mq.allow_merge(q, rq, bio);
- else if (!e->uses_mq && e->type->ops.sq.elevator_allow_bio_merge_fn)
- return e->type->ops.sq.elevator_allow_bio_merge_fn(q, rq, bio);
+ if (e->type->ops.allow_merge)
+ return e->type->ops.allow_merge(q, rq, bio);
return 1;
}
@@ -95,14 +93,14 @@ static bool elevator_match(const struct elevator_type *e, const char *name)
}
/*
- * Return scheduler with name 'name' and with matching 'mq capability
+ * Return scheduler with name 'name'
*/
-static struct elevator_type *elevator_find(const char *name, bool mq)
+static struct elevator_type *elevator_find(const char *name)
{
struct elevator_type *e;
list_for_each_entry(e, &elv_list, list) {
- if (elevator_match(e, name) && (mq == e->uses_mq))
+ if (elevator_match(e, name))
return e;
}
@@ -121,12 +119,12 @@ static struct elevator_type *elevator_get(struct request_queue *q,
spin_lock(&elv_list_lock);
- e = elevator_find(name, q->mq_ops != NULL);
+ e = elevator_find(name);
if (!e && try_loading) {
spin_unlock(&elv_list_lock);
request_module("%s-iosched", name);
spin_lock(&elv_list_lock);
- e = elevator_find(name, q->mq_ops != NULL);
+ e = elevator_find(name);
}
if (e && !try_module_get(e->elevator_owner))
@@ -150,26 +148,6 @@ static int __init elevator_setup(char *str)
__setup("elevator=", elevator_setup);
-/* called during boot to load the elevator chosen by the elevator param */
-void __init load_default_elevator_module(void)
-{
- struct elevator_type *e;
-
- if (!chosen_elevator[0])
- return;
-
- /*
- * Boot parameter is deprecated, we haven't supported that for MQ.
- * Only look for non-mq schedulers from here.
- */
- spin_lock(&elv_list_lock);
- e = elevator_find(chosen_elevator, false);
- spin_unlock(&elv_list_lock);
-
- if (!e)
- request_module("%s-iosched", chosen_elevator);
-}
-
static struct kobj_type elv_ktype;
struct elevator_queue *elevator_alloc(struct request_queue *q,
@@ -185,7 +163,6 @@ struct elevator_queue *elevator_alloc(struct request_queue *q,
kobject_init(&eq->kobj, &elv_ktype);
mutex_init(&eq->sysfs_lock);
hash_init(eq->hash);
- eq->uses_mq = e->uses_mq;
return eq;
}
@@ -200,54 +177,11 @@ static void elevator_release(struct kobject *kobj)
kfree(e);
}
-/*
- * Use the default elevator specified by config boot param for non-mq devices,
- * or by config option. Don't try to load modules as we could be running off
- * async and request_module() isn't allowed from async.
- */
-int elevator_init(struct request_queue *q)
-{
- struct elevator_type *e = NULL;
- int err = 0;
-
- /*
- * q->sysfs_lock must be held to provide mutual exclusion between
- * elevator_switch() and here.
- */
- mutex_lock(&q->sysfs_lock);
- if (unlikely(q->elevator))
- goto out_unlock;
-
- if (*chosen_elevator) {
- e = elevator_get(q, chosen_elevator, false);
- if (!e)
- printk(KERN_ERR "I/O scheduler %s not found\n",
- chosen_elevator);
- }
-
- if (!e)
- e = elevator_get(q, CONFIG_DEFAULT_IOSCHED, false);
- if (!e) {
- printk(KERN_ERR
- "Default I/O scheduler not found. Using noop.\n");
- e = elevator_get(q, "noop", false);
- }
-
- err = e->ops.sq.elevator_init_fn(q, e);
- if (err)
- elevator_put(e);
-out_unlock:
- mutex_unlock(&q->sysfs_lock);
- return err;
-}
-
void elevator_exit(struct request_queue *q, struct elevator_queue *e)
{
mutex_lock(&e->sysfs_lock);
- if (e->uses_mq && e->type->ops.mq.exit_sched)
+ if (e->type->ops.exit_sched)
blk_mq_exit_sched(q, e);
- else if (!e->uses_mq && e->type->ops.sq.elevator_exit_fn)
- e->type->ops.sq.elevator_exit_fn(e);
mutex_unlock(&e->sysfs_lock);
kobject_put(&e->kobj);
@@ -356,68 +290,6 @@ struct request *elv_rb_find(struct rb_root *root, sector_t sector)
}
EXPORT_SYMBOL(elv_rb_find);
-/*
- * Insert rq into dispatch queue of q. Queue lock must be held on
- * entry. rq is sort instead into the dispatch queue. To be used by
- * specific elevators.
- */
-void elv_dispatch_sort(struct request_queue *q, struct request *rq)
-{
- sector_t boundary;
- struct list_head *entry;
-
- if (q->last_merge == rq)
- q->last_merge = NULL;
-
- elv_rqhash_del(q, rq);
-
- q->nr_sorted--;
-
- boundary = q->end_sector;
- list_for_each_prev(entry, &q->queue_head) {
- struct request *pos = list_entry_rq(entry);
-
- if (req_op(rq) != req_op(pos))
- break;
- if (rq_data_dir(rq) != rq_data_dir(pos))
- break;
- if (pos->rq_flags & (RQF_STARTED | RQF_SOFTBARRIER))
- break;
- if (blk_rq_pos(rq) >= boundary) {
- if (blk_rq_pos(pos) < boundary)
- continue;
- } else {
- if (blk_rq_pos(pos) >= boundary)
- break;
- }
- if (blk_rq_pos(rq) >= blk_rq_pos(pos))
- break;
- }
-
- list_add(&rq->queuelist, entry);
-}
-EXPORT_SYMBOL(elv_dispatch_sort);
-
-/*
- * Insert rq into dispatch queue of q. Queue lock must be held on
- * entry. rq is added to the back of the dispatch queue. To be used by
- * specific elevators.
- */
-void elv_dispatch_add_tail(struct request_queue *q, struct request *rq)
-{
- if (q->last_merge == rq)
- q->last_merge = NULL;
-
- elv_rqhash_del(q, rq);
-
- q->nr_sorted--;
-
- q->end_sector = rq_end_sector(rq);
- q->boundary_rq = rq;
- list_add_tail(&rq->queuelist, &q->queue_head);
-}
-EXPORT_SYMBOL(elv_dispatch_add_tail);
-
enum elv_merge elv_merge(struct request_queue *q, struct request **req,
struct bio *bio)
{
@@ -457,10 +329,8 @@ enum elv_merge elv_merge(struct request_queue *q, struct request **req,
return ELEVATOR_BACK_MERGE;
}
- if (e->uses_mq && e->type->ops.mq.request_merge)
- return e->type->ops.mq.request_merge(q, req, bio);
- else if (!e->uses_mq && e->type->ops.sq.elevator_merge_fn)
- return e->type->ops.sq.elevator_merge_fn(q, req, bio);
+ if (e->type->ops.request_merge)
+ return e->type->ops.request_merge(q, req, bio);
return ELEVATOR_NO_MERGE;
}
@@ -511,10 +381,8 @@ void elv_merged_request(struct request_queue *q, struct request *rq,
{
struct elevator_queue *e = q->elevator;
- if (e->uses_mq && e->type->ops.mq.request_merged)
- e->type->ops.mq.request_merged(q, rq, type);
- else if (!e->uses_mq && e->type->ops.sq.elevator_merged_fn)
- e->type->ops.sq.elevator_merged_fn(q, rq, type);
+ if (e->type->ops.request_merged)
+ e->type->ops.request_merged(q, rq, type);
if (type == ELEVATOR_BACK_MERGE)
elv_rqhash_reposition(q, rq);
@@ -526,176 +394,20 @@ void elv_merge_requests(struct request_queue *q, struct request *rq,
struct request *next)
{
struct elevator_queue *e = q->elevator;
- bool next_sorted = false;
-
- if (e->uses_mq && e->type->ops.mq.requests_merged)
- e->type->ops.mq.requests_merged(q, rq, next);
- else if (e->type->ops.sq.elevator_merge_req_fn) {
- next_sorted = (__force bool)(next->rq_flags & RQF_SORTED);
- if (next_sorted)
- e->type->ops.sq.elevator_merge_req_fn(q, rq, next);
- }
- elv_rqhash_reposition(q, rq);
-
- if (next_sorted) {
- elv_rqhash_del(q, next);
- q->nr_sorted--;
- }
+ if (e->type->ops.requests_merged)
+ e->type->ops.requests_merged(q, rq, next);
+ elv_rqhash_reposition(q, rq);
q->last_merge = rq;
}
-void elv_bio_merged(struct request_queue *q, struct request *rq,
- struct bio *bio)
-{
- struct elevator_queue *e = q->elevator;
-
- if (WARN_ON_ONCE(e->uses_mq))
- return;
-
- if (e->type->ops.sq.elevator_bio_merged_fn)
- e->type->ops.sq.elevator_bio_merged_fn(q, rq, bio);
-}
-
-void elv_requeue_request(struct request_queue *q, struct request *rq)
-{
- /*
- * it already went through dequeue, we need to decrement the
- * in_flight count again
- */
- if (blk_account_rq(rq)) {
- q->in_flight[rq_is_sync(rq)]--;
- if (rq->rq_flags & RQF_SORTED)
- elv_deactivate_rq(q, rq);
- }
-
- rq->rq_flags &= ~RQF_STARTED;
-
- blk_pm_requeue_request(rq);
-
- __elv_add_request(q, rq, ELEVATOR_INSERT_REQUEUE);
-}
-
-void elv_drain_elevator(struct request_queue *q)
-{
- struct elevator_queue *e = q->elevator;
- static int printed;
-
- if (WARN_ON_ONCE(e->uses_mq))
- return;
-
- lockdep_assert_held(q->queue_lock);
-
- while (e->type->ops.sq.elevator_dispatch_fn(q, 1))
- ;
- if (q->nr_sorted && !blk_queue_is_zoned(q) && printed++ < 10 ) {
- printk(KERN_ERR "%s: forced dispatching is broken "
- "(nr_sorted=%u), please report this\n",
- q->elevator->type->elevator_name, q->nr_sorted);
- }
-}
-
-void __elv_add_request(struct request_queue *q, struct request *rq, int where)
-{
- trace_block_rq_insert(q, rq);
-
- blk_pm_add_request(q, rq);
-
- rq->q = q;
-
- if (rq->rq_flags & RQF_SOFTBARRIER) {
- /* barriers are scheduling boundary, update end_sector */
- if (!blk_rq_is_passthrough(rq)) {
- q->end_sector = rq_end_sector(rq);
- q->boundary_rq = rq;
- }
- } else if (!(rq->rq_flags & RQF_ELVPRIV) &&
- (where == ELEVATOR_INSERT_SORT ||
- where == ELEVATOR_INSERT_SORT_MERGE))
- where = ELEVATOR_INSERT_BACK;
-
- switch (where) {
- case ELEVATOR_INSERT_REQUEUE:
- case ELEVATOR_INSERT_FRONT:
- rq->rq_flags |= RQF_SOFTBARRIER;
- list_add(&rq->queuelist, &q->queue_head);
- break;
-
- case ELEVATOR_INSERT_BACK:
- rq->rq_flags |= RQF_SOFTBARRIER;
- elv_drain_elevator(q);
- list_add_tail(&rq->queuelist, &q->queue_head);
- /*
- * We kick the queue here for the following reasons.
- * - The elevator might have returned NULL previously
- * to delay requests and returned them now. As the
- * queue wasn't empty before this request, ll_rw_blk
- * won't run the queue on return, resulting in hang.
- * - Usually, back inserted requests won't be merged
- * with anything. There's no point in delaying queue
- * processing.
- */
- __blk_run_queue(q);
- break;
-
- case ELEVATOR_INSERT_SORT_MERGE:
- /*
- * If we succeed in merging this request with one in the
- * queue already, we are done - rq has now been freed,
- * so no need to do anything further.
- */
- if (elv_attempt_insert_merge(q, rq))
- break;
- /* fall through */
- case ELEVATOR_INSERT_SORT:
- BUG_ON(blk_rq_is_passthrough(rq));
- rq->rq_flags |= RQF_SORTED;
- q->nr_sorted++;
- if (rq_mergeable(rq)) {
- elv_rqhash_add(q, rq);
- if (!q->last_merge)
- q->last_merge = rq;
- }
-
- /*
- * Some ioscheds (cfq) run q->request_fn directly, so
- * rq cannot be accessed after calling
- * elevator_add_req_fn.
- */
- q->elevator->type->ops.sq.elevator_add_req_fn(q, rq);
- break;
-
- case ELEVATOR_INSERT_FLUSH:
- rq->rq_flags |= RQF_SOFTBARRIER;
- blk_insert_flush(rq);
- break;
- default:
- printk(KERN_ERR "%s: bad insertion point %d\n",
- __func__, where);
- BUG();
- }
-}
-EXPORT_SYMBOL(__elv_add_request);
-
-void elv_add_request(struct request_queue *q, struct request *rq, int where)
-{
- unsigned long flags;
-
- spin_lock_irqsave(q->queue_lock, flags);
- __elv_add_request(q, rq, where);
- spin_unlock_irqrestore(q->queue_lock, flags);
-}
-EXPORT_SYMBOL(elv_add_request);
-
struct request *elv_latter_request(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;
- if (e->uses_mq && e->type->ops.mq.next_request)
- return e->type->ops.mq.next_request(q, rq);
- else if (!e->uses_mq && e->type->ops.sq.elevator_latter_req_fn)
- return e->type->ops.sq.elevator_latter_req_fn(q, rq);
+ if (e->type->ops.next_request)
+ return e->type->ops.next_request(q, rq);
return NULL;
}
@@ -704,66 +416,10 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)
{
struct elevator_queue *e = q->elevator;
- if (e->uses_mq && e->type->ops.mq.former_request)
- return e->type->ops.mq.former_request(q, rq);
- if (!e->uses_mq && e->type->ops.sq.elevator_former_req_fn)
- return e->type->ops.sq.elevator_former_req_fn(q, rq);
- return NULL;
-}
-
-int elv_set_request(struct request_queue *q, struct request *rq,
- struct bio *bio, gfp_t gfp_mask)
-{
- struct elevator_queue *e = q->elevator;
-
- if (WARN_ON_ONCE(e->uses_mq))
- return 0;
-
- if (e->type->ops.sq.elevator_set_req_fn)
- return e->type->ops.sq.elevator_set_req_fn(q, rq, bio, gfp_mask);
- return 0;
-}
-
-void elv_put_request(struct request_queue *q, struct request *rq)
-{
- struct elevator_queue *e = q->elevator;
-
- if (WARN_ON_ONCE(e->uses_mq))
- return;
-
- if (e->type->ops.sq.elevator_put_req_fn)
- e->type->ops.sq.elevator_put_req_fn(rq);
-}
-
-int elv_may_queue(struct request_queue *q, unsigned int op)
-{
- struct elevator_queue *e = q->elevator;
-
- if (WARN_ON_ONCE(e->uses_mq))
- return 0;
-
- if (e->type->ops.sq.elevator_may_queue_fn)
- return e->type->ops.sq.elevator_may_queue_fn(q, op);
-
- return ELV_MQUEUE_MAY;
-}
-
-void elv_completed_request(struct request_queue *q, struct request *rq)
-{
- struct elevator_queue *e = q->elevator;
-
- if (WARN_ON_ONCE(e->uses_mq))
- return;
+ if (e->type->ops.former_request)
+ return e->type->ops.former_request(q, rq);
- /*
- * request is released from the driver, io must be done
- */
- if (blk_account_rq(rq)) {
- q->in_flight[rq_is_sync(rq)]--;
- if ((rq->rq_flags & RQF_SORTED) &&
- e->type->ops.sq.elevator_completed_req_fn)
- e->type->ops.sq.elevator_completed_req_fn(q, rq);
- }
+ return NULL;
}
#define to_elv(atr) container_of((atr), struct elv_fs_entry, attr)
@@ -832,8 +488,6 @@ int elv_register_queue(struct request_queue *q)
}
kobject_uevent(&e->kobj, KOBJ_ADD);
e->registered = 1;
- if (!e->uses_mq && e->type->ops.sq.elevator_registered_fn)
- e->type->ops.sq.elevator_registered_fn(q);
}
return error;
}
@@ -873,7 +527,7 @@ int elv_register(struct elevator_type *e)
/* register, don't allow duplicate names */
spin_lock(&elv_list_lock);
- if (elevator_find(e->elevator_name, e->uses_mq)) {
+ if (elevator_find(e->elevator_name)) {
spin_unlock(&elv_list_lock);
kmem_cache_destroy(e->icq_cache);
return -EBUSY;
@@ -881,12 +535,6 @@ int elv_register(struct elevator_type *e)
list_add_tail(&e->list, &elv_list);
spin_unlock(&elv_list_lock);
- /* print pretty message */
- if (elevator_match(e, chosen_elevator) ||
- (!*chosen_elevator &&
- elevator_match(e, CONFIG_DEFAULT_IOSCHED)))
- def = " (default)";
-
printk(KERN_INFO "io scheduler %s registered%s\n", e->elevator_name,
def);
return 0;
@@ -989,71 +637,17 @@ out_unlock:
*/
static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
{
- struct elevator_queue *old = q->elevator;
- bool old_registered = false;
int err;
lockdep_assert_held(&q->sysfs_lock);
- if (q->mq_ops) {
- blk_mq_freeze_queue(q);
- blk_mq_quiesce_queue(q);
-
- err = elevator_switch_mq(q, new_e);
-
- blk_mq_unquiesce_queue(q);
- blk_mq_unfreeze_queue(q);
-
- return err;
- }
-
- /*
- * Turn on BYPASS and drain all requests w/ elevator private data.
- * Block layer doesn't call into a quiesced elevator - all requests
- * are directly put on the dispatch list without elevator data
- * using INSERT_BACK. All requests have SOFTBARRIER set and no
- * merge happens either.
- */
- if (old) {
- old_registered = old->registered;
-
- blk_queue_bypass_start(q);
-
- /* unregister and clear all auxiliary data of the old elevator */
- if (old_registered)
- elv_unregister_queue(q);
-
- ioc_clear_queue(q);
- }
+ blk_mq_freeze_queue(q);
+ blk_mq_quiesce_queue(q);
- /* allocate, init and register new elevator */
- err = new_e->ops.sq.elevator_init_fn(q, new_e);
- if (err)
- goto fail_init;
-
- err = elv_register_queue(q);
- if (err)
- goto fail_register;
-
- /* done, kill the old one and finish */
- if (old) {
- elevator_exit(q, old);
- blk_queue_bypass_end(q);
- }
+ err = elevator_switch_mq(q, new_e);
- blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
-
- return 0;
-
-fail_register:
- elevator_exit(q, q->elevator);
-fail_init:
- /* switch failed, restore and re-register old elevator */
- if (old) {
- q->elevator = old;
- elv_register_queue(q);
- blk_queue_bypass_end(q);
- }
+ blk_mq_unquiesce_queue(q);
+ blk_mq_unfreeze_queue(q);
return err;
}
@@ -1073,7 +667,7 @@ static int __elevator_change(struct request_queue *q, const char *name)
/*
* Special case for mq, turn off scheduling
*/
- if (q->mq_ops && !strncmp(name, "none", 4))
+ if (!strncmp(name, "none", 4))
return elevator_switch(q, NULL);
strlcpy(elevator_name, name, sizeof(elevator_name));
@@ -1091,8 +685,7 @@ static int __elevator_change(struct request_queue *q, const char *name)
static inline bool elv_support_iosched(struct request_queue *q)
{
- if (q->mq_ops && q->tag_set && (q->tag_set->flags &
- BLK_MQ_F_NO_SCHED))
+ if (q->tag_set && (q->tag_set->flags & BLK_MQ_F_NO_SCHED))
return false;
return true;
}
@@ -1102,7 +695,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
{
int ret;
- if (!(q->mq_ops || q->request_fn) || !elv_support_iosched(q))
+ if (!queue_is_mq(q) || !elv_support_iosched(q))
return count;
ret = __elevator_change(q, name);
@@ -1117,10 +710,9 @@ 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))
+ if (!queue_is_mq(q))
return sprintf(name, "none\n");
if (!q->elevator)
@@ -1130,19 +722,16 @@ 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 && elevator_match(elv, __e->elevator_name) &&
- (__e->uses_mq == uses_mq)) {
+ if (elv && elevator_match(elv, __e->elevator_name)) {
len += sprintf(name+len, "[%s] ", elv->elevator_name);
continue;
}
- if (__e->uses_mq && q->mq_ops && elv_support_iosched(q))
- len += sprintf(name+len, "%s ", __e->elevator_name);
- else if (!__e->uses_mq && !q->mq_ops)
+ if (elv_support_iosched(q))
len += sprintf(name+len, "%s ", __e->elevator_name);
}
spin_unlock(&elv_list_lock);
- if (q->mq_ops && q->elevator)
+ if (q->elevator)
len += sprintf(name+len, "none");
len += sprintf(len+name, "\n");