]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blobdiff - block/elevator.c
blk-mq-debugfs: Add missing __acquires() / __releases() annotations
[mirror_ubuntu-artful-kernel.git] / block / elevator.c
index 40f0c04e5ad3d076ee24d34f3424b9e42194d454..dba9be891a6b6e52ade80b7c47b1dcfc190ef9d9 100644 (file)
@@ -40,6 +40,7 @@
 #include <trace/events/block.h>
 
 #include "blk.h"
+#include "blk-mq-sched.h"
 
 static DEFINE_SPINLOCK(elv_list_lock);
 static LIST_HEAD(elv_list);
@@ -58,8 +59,10 @@ 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->type->ops.elevator_allow_bio_merge_fn)
-               return e->type->ops.elevator_allow_bio_merge_fn(q, rq, bio);
+       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);
 
        return 1;
 }
@@ -163,6 +166,7 @@ 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;
 }
@@ -215,18 +219,32 @@ int elevator_init(struct request_queue *q, char *name)
        }
 
        if (!e) {
-               e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
+               if (q->mq_ops && q->nr_hw_queues == 1)
+                       e = elevator_get(CONFIG_DEFAULT_SQ_IOSCHED, false);
+               else if (q->mq_ops)
+                       e = elevator_get(CONFIG_DEFAULT_MQ_IOSCHED, false);
+               else
+                       e = elevator_get(CONFIG_DEFAULT_IOSCHED, false);
+
                if (!e) {
                        printk(KERN_ERR
                                "Default I/O scheduler not found. " \
-                               "Using noop.\n");
+                               "Using noop/none.\n");
                        e = elevator_get("noop", false);
                }
        }
 
-       err = e->ops.elevator_init_fn(q, e);
-       if (err)
+       if (e->uses_mq) {
+               err = blk_mq_sched_setup(q);
+               if (!err)
+                       err = e->ops.mq.init_sched(q, e);
+       } else
+               err = e->ops.sq.elevator_init_fn(q, e);
+       if (err) {
+               if (e->uses_mq)
+                       blk_mq_sched_teardown(q);
                elevator_put(e);
+       }
        return err;
 }
 EXPORT_SYMBOL(elevator_init);
@@ -234,8 +252,10 @@ EXPORT_SYMBOL(elevator_init);
 void elevator_exit(struct elevator_queue *e)
 {
        mutex_lock(&e->sysfs_lock);
-       if (e->type->ops.elevator_exit_fn)
-               e->type->ops.elevator_exit_fn(e);
+       if (e->uses_mq && e->type->ops.mq.exit_sched)
+               e->type->ops.mq.exit_sched(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);
@@ -253,6 +273,7 @@ void elv_rqhash_del(struct request_queue *q, struct request *rq)
        if (ELV_ON_HASH(rq))
                __elv_rqhash_del(rq);
 }
+EXPORT_SYMBOL_GPL(elv_rqhash_del);
 
 void elv_rqhash_add(struct request_queue *q, struct request *rq)
 {
@@ -262,6 +283,7 @@ void elv_rqhash_add(struct request_queue *q, struct request *rq)
        hash_add(e->hash, &rq->hash, rq_hash_key(rq));
        rq->rq_flags |= RQF_HASHED;
 }
+EXPORT_SYMBOL_GPL(elv_rqhash_add);
 
 void elv_rqhash_reposition(struct request_queue *q, struct request *rq)
 {
@@ -443,8 +465,10 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
                return ELEVATOR_BACK_MERGE;
        }
 
-       if (e->type->ops.elevator_merge_fn)
-               return e->type->ops.elevator_merge_fn(q, req, bio);
+       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);
 
        return ELEVATOR_NO_MERGE;
 }
@@ -456,8 +480,7 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio)
  *
  * Returns true if we merged, false otherwise
  */
-static bool elv_attempt_insert_merge(struct request_queue *q,
-                                    struct request *rq)
+bool elv_attempt_insert_merge(struct request_queue *q, struct request *rq)
 {
        struct request *__rq;
        bool ret;
@@ -495,8 +518,10 @@ void elv_merged_request(struct request_queue *q, struct request *rq, int type)
 {
        struct elevator_queue *e = q->elevator;
 
-       if (e->type->ops.elevator_merged_fn)
-               e->type->ops.elevator_merged_fn(q, rq, type);
+       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 (type == ELEVATOR_BACK_MERGE)
                elv_rqhash_reposition(q, rq);
@@ -508,10 +533,15 @@ void elv_merge_requests(struct request_queue *q, struct request *rq,
                             struct request *next)
 {
        struct elevator_queue *e = q->elevator;
-       const int next_sorted = next->rq_flags & RQF_SORTED;
-
-       if (next_sorted && e->type->ops.elevator_merge_req_fn)
-               e->type->ops.elevator_merge_req_fn(q, rq, next);
+       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 = next->rq_flags & RQF_SORTED;
+               if (next_sorted)
+                       e->type->ops.sq.elevator_merge_req_fn(q, rq, next);
+       }
 
        elv_rqhash_reposition(q, rq);
 
@@ -528,8 +558,11 @@ void elv_bio_merged(struct request_queue *q, struct request *rq,
 {
        struct elevator_queue *e = q->elevator;
 
-       if (e->type->ops.elevator_bio_merged_fn)
-               e->type->ops.elevator_bio_merged_fn(q, rq, bio);
+       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);
 }
 
 #ifdef CONFIG_PM
@@ -574,11 +607,15 @@ void elv_requeue_request(struct request_queue *q, struct request *rq)
 
 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 (q->elevator->type->ops.elevator_dispatch_fn(q, 1))
+       while (e->type->ops.sq.elevator_dispatch_fn(q, 1))
                ;
        if (q->nr_sorted && printed++ < 10) {
                printk(KERN_ERR "%s: forced dispatching is broken "
@@ -597,7 +634,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
 
        if (rq->rq_flags & RQF_SOFTBARRIER) {
                /* barriers are scheduling boundary, update end_sector */
-               if (rq->cmd_type == REQ_TYPE_FS) {
+               if (!blk_rq_is_passthrough(rq)) {
                        q->end_sector = rq_end_sector(rq);
                        q->boundary_rq = rq;
                }
@@ -639,7 +676,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
                if (elv_attempt_insert_merge(q, rq))
                        break;
        case ELEVATOR_INSERT_SORT:
-               BUG_ON(rq->cmd_type != REQ_TYPE_FS);
+               BUG_ON(blk_rq_is_passthrough(rq));
                rq->rq_flags |= RQF_SORTED;
                q->nr_sorted++;
                if (rq_mergeable(rq)) {
@@ -653,7 +690,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where)
                 * rq cannot be accessed after calling
                 * elevator_add_req_fn.
                 */
-               q->elevator->type->ops.elevator_add_req_fn(q, rq);
+               q->elevator->type->ops.sq.elevator_add_req_fn(q, rq);
                break;
 
        case ELEVATOR_INSERT_FLUSH:
@@ -682,8 +719,11 @@ struct request *elv_latter_request(struct request_queue *q, struct request *rq)
 {
        struct elevator_queue *e = q->elevator;
 
-       if (e->type->ops.elevator_latter_req_fn)
-               return e->type->ops.elevator_latter_req_fn(q, rq);
+       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);
+
        return NULL;
 }
 
@@ -691,8 +731,10 @@ struct request *elv_former_request(struct request_queue *q, struct request *rq)
 {
        struct elevator_queue *e = q->elevator;
 
-       if (e->type->ops.elevator_former_req_fn)
-               return e->type->ops.elevator_former_req_fn(q, rq);
+       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;
 }
 
@@ -701,8 +743,11 @@ int elv_set_request(struct request_queue *q, struct request *rq,
 {
        struct elevator_queue *e = q->elevator;
 
-       if (e->type->ops.elevator_set_req_fn)
-               return e->type->ops.elevator_set_req_fn(q, rq, bio, gfp_mask);
+       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;
 }
 
@@ -710,16 +755,22 @@ void elv_put_request(struct request_queue *q, struct request *rq)
 {
        struct elevator_queue *e = q->elevator;
 
-       if (e->type->ops.elevator_put_req_fn)
-               e->type->ops.elevator_put_req_fn(rq);
+       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 (e->type->ops.elevator_may_queue_fn)
-               return e->type->ops.elevator_may_queue_fn(q, op);
+       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;
 }
@@ -728,14 +779,17 @@ 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;
+
        /*
         * 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.elevator_completed_req_fn)
-                       e->type->ops.elevator_completed_req_fn(q, rq);
+                   e->type->ops.sq.elevator_completed_req_fn)
+                       e->type->ops.sq.elevator_completed_req_fn(q, rq);
        }
 }
 
@@ -803,8 +857,8 @@ int elv_register_queue(struct request_queue *q)
                }
                kobject_uevent(&e->kobj, KOBJ_ADD);
                e->registered = 1;
-               if (e->type->ops.elevator_registered_fn)
-                       e->type->ops.elevator_registered_fn(q);
+               if (!e->uses_mq && e->type->ops.sq.elevator_registered_fn)
+                       e->type->ops.sq.elevator_registered_fn(q);
        }
        return error;
 }
@@ -891,9 +945,14 @@ EXPORT_SYMBOL_GPL(elv_unregister);
 static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
 {
        struct elevator_queue *old = q->elevator;
-       bool registered = old->registered;
+       bool old_registered = false;
        int err;
 
+       if (q->mq_ops) {
+               blk_mq_freeze_queue(q);
+               blk_mq_quiesce_queue(q);
+       }
+
        /*
         * Turn on BYPASS and drain all requests w/ elevator private data.
         * Block layer doesn't call into a quiesced elevator - all requests
@@ -901,42 +960,76 @@ static int elevator_switch(struct request_queue *q, struct elevator_type *new_e)
         * using INSERT_BACK.  All requests have SOFTBARRIER set and no
         * merge happens either.
         */
-       blk_queue_bypass_start(q);
+       if (old) {
+               old_registered = old->registered;
 
-       /* unregister and clear all auxiliary data of the old elevator */
-       if (registered)
-               elv_unregister_queue(q);
+               if (old->uses_mq)
+                       blk_mq_sched_teardown(q);
 
-       spin_lock_irq(q->queue_lock);
-       ioc_clear_queue(q);
-       spin_unlock_irq(q->queue_lock);
+               if (!q->mq_ops)
+                       blk_queue_bypass_start(q);
+
+               /* unregister and clear all auxiliary data of the old elevator */
+               if (old_registered)
+                       elv_unregister_queue(q);
+
+               spin_lock_irq(q->queue_lock);
+               ioc_clear_queue(q);
+               spin_unlock_irq(q->queue_lock);
+       }
 
        /* allocate, init and register new elevator */
-       err = new_e->ops.elevator_init_fn(q, new_e);
-       if (err)
-               goto fail_init;
+       if (new_e) {
+               if (new_e->uses_mq) {
+                       err = blk_mq_sched_setup(q);
+                       if (!err)
+                               err = new_e->ops.mq.init_sched(q, new_e);
+               } else
+                       err = new_e->ops.sq.elevator_init_fn(q, new_e);
+               if (err)
+                       goto fail_init;
 
-       if (registered) {
                err = elv_register_queue(q);
                if (err)
                        goto fail_register;
-       }
+       } else
+               q->elevator = NULL;
 
        /* done, kill the old one and finish */
-       elevator_exit(old);
-       blk_queue_bypass_end(q);
+       if (old) {
+               elevator_exit(old);
+               if (!q->mq_ops)
+                       blk_queue_bypass_end(q);
+       }
 
-       blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+       if (q->mq_ops) {
+               blk_mq_unfreeze_queue(q);
+               blk_mq_start_stopped_hw_queues(q, true);
+       }
+
+       if (new_e)
+               blk_add_trace_msg(q, "elv switch: %s", new_e->elevator_name);
+       else
+               blk_add_trace_msg(q, "elv switch: none");
 
        return 0;
 
 fail_register:
+       if (q->mq_ops)
+               blk_mq_sched_teardown(q);
        elevator_exit(q->elevator);
 fail_init:
        /* switch failed, restore and re-register old elevator */
-       q->elevator = old;
-       elv_register_queue(q);
-       blk_queue_bypass_end(q);
+       if (old) {
+               q->elevator = old;
+               elv_register_queue(q);
+               if (!q->mq_ops)
+                       blk_queue_bypass_end(q);
+       }
+       if (q->mq_ops) {
+               blk_mq_unfreeze_queue(q);
+               blk_mq_start_stopped_hw_queues(q, true);
+       }
 
        return err;
 }
@@ -949,8 +1042,11 @@ static int __elevator_change(struct request_queue *q, const char *name)
        char elevator_name[ELV_NAME_MAX];
        struct elevator_type *e;
 
-       if (!q->elevator)
-               return -ENXIO;
+       /*
+        * Special case for mq, turn off scheduling
+        */
+       if (q->mq_ops && !strncmp(name, "none", 4))
+               return elevator_switch(q, NULL);
 
        strlcpy(elevator_name, name, sizeof(elevator_name));
        e = elevator_get(strstrip(elevator_name), true);
@@ -959,11 +1055,21 @@ static int __elevator_change(struct request_queue *q, const char *name)
                return -EINVAL;
        }
 
-       if (!strcmp(elevator_name, q->elevator->type->elevator_name)) {
+       if (q->elevator &&
+           !strcmp(elevator_name, q->elevator->type->elevator_name)) {
                elevator_put(e);
                return 0;
        }
 
+       if (!e->uses_mq && q->mq_ops) {
+               elevator_put(e);
+               return -EINVAL;
+       }
+       if (e->uses_mq && !q->mq_ops) {
+               elevator_put(e);
+               return -EINVAL;
+       }
+
        return elevator_switch(q, e);
 }
 
@@ -985,7 +1091,7 @@ ssize_t elv_iosched_store(struct request_queue *q, const char *name,
 {
        int ret;
 
-       if (!q->elevator)
+       if (!(q->mq_ops || q->request_fn))
                return count;
 
        ret = __elevator_change(q, name);
@@ -999,24 +1105,34 @@ 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;
+       struct elevator_type *elv = NULL;
        struct elevator_type *__e;
        int len = 0;
 
-       if (!q->elevator || !blk_queue_stackable(q))
+       if (!blk_queue_stackable(q))
                return sprintf(name, "none\n");
 
-       elv = e->type;
+       if (!q->elevator)
+               len += sprintf(name+len, "[none] ");
+       else
+               elv = e->type;
 
        spin_lock(&elv_list_lock);
        list_for_each_entry(__e, &elv_list, list) {
-               if (!strcmp(elv->elevator_name, __e->elevator_name))
+               if (elv && !strcmp(elv->elevator_name, __e->elevator_name)) {
                        len += sprintf(name+len, "[%s] ", elv->elevator_name);
-               else
+                       continue;
+               }
+               if (__e->uses_mq && q->mq_ops)
+                       len += sprintf(name+len, "%s ", __e->elevator_name);
+               else if (!__e->uses_mq && !q->mq_ops)
                        len += sprintf(name+len, "%s ", __e->elevator_name);
        }
        spin_unlock(&elv_list_lock);
 
+       if (q->mq_ops && q->elevator)
+               len += sprintf(name+len, "none");
+
        len += sprintf(len+name, "\n");
        return len;
 }