Merge branch 'for-4.6/core' of git://git.kernel.dk/linux-block
[cascardo/linux.git] / block / blk-mq.c
index 56c0a72..050f7a1 100644 (file)
@@ -544,7 +544,10 @@ EXPORT_SYMBOL(blk_mq_abort_requeue_list);
 
 struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
 {
-       return tags->rqs[tag];
+       if (tag < tags->nr_tags)
+               return tags->rqs[tag];
+
+       return NULL;
 }
 EXPORT_SYMBOL(blk_mq_tag_to_rq);
 
@@ -1744,31 +1747,6 @@ static int blk_mq_init_hctx(struct request_queue *q,
        return -1;
 }
 
-static int blk_mq_init_hw_queues(struct request_queue *q,
-               struct blk_mq_tag_set *set)
-{
-       struct blk_mq_hw_ctx *hctx;
-       unsigned int i;
-
-       /*
-        * Initialize hardware queues
-        */
-       queue_for_each_hw_ctx(q, hctx, i) {
-               if (blk_mq_init_hctx(q, set, hctx, i))
-                       break;
-       }
-
-       if (i == q->nr_hw_queues)
-               return 0;
-
-       /*
-        * Init failed
-        */
-       blk_mq_exit_hw_queues(q, set, i);
-
-       return 1;
-}
-
 static void blk_mq_init_cpu_queues(struct request_queue *q,
                                   unsigned int nr_hw_queues)
 {
@@ -1826,6 +1804,7 @@ static void blk_mq_map_swqueue(struct request_queue *q,
                        continue;
 
                hctx = q->mq_ops->map_queue(q, i);
+
                cpumask_set_cpu(i, hctx->cpumask);
                ctx->index_hw = hctx->nr_ctx;
                hctx->ctxs[hctx->nr_ctx++] = ctx;
@@ -1974,56 +1953,93 @@ struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
 }
 EXPORT_SYMBOL(blk_mq_init_queue);
 
-struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
-                                                 struct request_queue *q)
+static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
+                                               struct request_queue *q)
 {
-       struct blk_mq_hw_ctx **hctxs;
-       struct blk_mq_ctx __percpu *ctx;
-       unsigned int *map;
-       int i;
-
-       ctx = alloc_percpu(struct blk_mq_ctx);
-       if (!ctx)
-               return ERR_PTR(-ENOMEM);
-
-       hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
-                       set->numa_node);
-
-       if (!hctxs)
-               goto err_percpu;
-
-       map = blk_mq_make_queue_map(set);
-       if (!map)
-               goto err_map;
+       int i, j;
+       struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
 
+       blk_mq_sysfs_unregister(q);
        for (i = 0; i < set->nr_hw_queues; i++) {
-               int node = blk_mq_hw_queue_to_node(map, i);
+               int node;
 
+               if (hctxs[i])
+                       continue;
+
+               node = blk_mq_hw_queue_to_node(q->mq_map, i);
                hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
                                        GFP_KERNEL, node);
                if (!hctxs[i])
-                       goto err_hctxs;
+                       break;
 
                if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
-                                               node))
-                       goto err_hctxs;
+                                               node)) {
+                       kfree(hctxs[i]);
+                       hctxs[i] = NULL;
+                       break;
+               }
 
                atomic_set(&hctxs[i]->nr_active, 0);
                hctxs[i]->numa_node = node;
                hctxs[i]->queue_num = i;
+
+               if (blk_mq_init_hctx(q, set, hctxs[i], i)) {
+                       free_cpumask_var(hctxs[i]->cpumask);
+                       kfree(hctxs[i]);
+                       hctxs[i] = NULL;
+                       break;
+               }
+               blk_mq_hctx_kobj_init(hctxs[i]);
        }
+       for (j = i; j < q->nr_hw_queues; j++) {
+               struct blk_mq_hw_ctx *hctx = hctxs[j];
+
+               if (hctx) {
+                       if (hctx->tags) {
+                               blk_mq_free_rq_map(set, hctx->tags, j);
+                               set->tags[j] = NULL;
+                       }
+                       blk_mq_exit_hctx(q, set, hctx, j);
+                       free_cpumask_var(hctx->cpumask);
+                       kobject_put(&hctx->kobj);
+                       kfree(hctx->ctxs);
+                       kfree(hctx);
+                       hctxs[j] = NULL;
+
+               }
+       }
+       q->nr_hw_queues = i;
+       blk_mq_sysfs_register(q);
+}
+
+struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
+                                                 struct request_queue *q)
+{
+       /* mark the queue as mq asap */
+       q->mq_ops = set->ops;
+
+       q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
+       if (!q->queue_ctx)
+               return ERR_PTR(-ENOMEM);
+
+       q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)),
+                                               GFP_KERNEL, set->numa_node);
+       if (!q->queue_hw_ctx)
+               goto err_percpu;
+
+       q->mq_map = blk_mq_make_queue_map(set);
+       if (!q->mq_map)
+               goto err_map;
+
+       blk_mq_realloc_hw_ctxs(set, q);
+       if (!q->nr_hw_queues)
+               goto err_hctxs;
 
        INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
        blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
 
        q->nr_queues = nr_cpu_ids;
-       q->nr_hw_queues = set->nr_hw_queues;
-       q->mq_map = map;
-
-       q->queue_ctx = ctx;
-       q->queue_hw_ctx = hctxs;
 
-       q->mq_ops = set->ops;
        q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
 
        if (!(set->flags & BLK_MQ_F_SG_MERGE))
@@ -2050,9 +2066,6 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 
        blk_mq_init_cpu_queues(q, set->nr_hw_queues);
 
-       if (blk_mq_init_hw_queues(q, set))
-               goto err_hctxs;
-
        get_online_cpus();
        mutex_lock(&all_q_mutex);
 
@@ -2066,17 +2079,11 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
        return q;
 
 err_hctxs:
-       kfree(map);
-       for (i = 0; i < set->nr_hw_queues; i++) {
-               if (!hctxs[i])
-                       break;
-               free_cpumask_var(hctxs[i]->cpumask);
-               kfree(hctxs[i]);
-       }
+       kfree(q->mq_map);
 err_map:
-       kfree(hctxs);
+       kfree(q->queue_hw_ctx);
 err_percpu:
-       free_percpu(ctx);
+       free_percpu(q->queue_ctx);
        return ERR_PTR(-ENOMEM);
 }
 EXPORT_SYMBOL(blk_mq_init_allocated_queue);
@@ -2284,9 +2291,13 @@ int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
                set->nr_hw_queues = 1;
                set->queue_depth = min(64U, set->queue_depth);
        }
+       /*
+        * There is no use for more h/w queues than cpus.
+        */
+       if (set->nr_hw_queues > nr_cpu_ids)
+               set->nr_hw_queues = nr_cpu_ids;
 
-       set->tags = kmalloc_node(set->nr_hw_queues *
-                                sizeof(struct blk_mq_tags *),
+       set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *),
                                 GFP_KERNEL, set->numa_node);
        if (!set->tags)
                return -ENOMEM;
@@ -2309,7 +2320,7 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
 {
        int i;
 
-       for (i = 0; i < set->nr_hw_queues; i++) {
+       for (i = 0; i < nr_cpu_ids; i++) {
                if (set->tags[i])
                        blk_mq_free_rq_map(set, set->tags[i], i);
        }
@@ -2330,6 +2341,8 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
 
        ret = 0;
        queue_for_each_hw_ctx(q, hctx, i) {
+               if (!hctx->tags)
+                       continue;
                ret = blk_mq_tag_update_depth(hctx->tags, nr);
                if (ret)
                        break;
@@ -2341,6 +2354,35 @@ int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
        return ret;
 }
 
+void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
+{
+       struct request_queue *q;
+
+       if (nr_hw_queues > nr_cpu_ids)
+               nr_hw_queues = nr_cpu_ids;
+       if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
+               return;
+
+       list_for_each_entry(q, &set->tag_list, tag_set_list)
+               blk_mq_freeze_queue(q);
+
+       set->nr_hw_queues = nr_hw_queues;
+       list_for_each_entry(q, &set->tag_list, tag_set_list) {
+               blk_mq_realloc_hw_ctxs(set, q);
+
+               if (q->nr_hw_queues > 1)
+                       blk_queue_make_request(q, blk_mq_make_request);
+               else
+                       blk_queue_make_request(q, blk_sq_make_request);
+
+               blk_mq_queue_reinit(q, cpu_online_mask);
+       }
+
+       list_for_each_entry(q, &set->tag_list, tag_set_list)
+               blk_mq_unfreeze_queue(q);
+}
+EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
+
 void blk_mq_disable_hotplug(void)
 {
        mutex_lock(&all_q_mutex);