diff options
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r-- | block/blk-mq.c | 118 |
1 files changed, 77 insertions, 41 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c index 2077f0d..d921cd5 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -394,14 +394,16 @@ void __blk_mq_complete_request(struct request *rq) * Ends all I/O on a request. It does not handle partial completions. * The actual completion happens out-of-order, through a IPI handler. **/ -void blk_mq_complete_request(struct request *rq) +void blk_mq_complete_request(struct request *rq, int error) { struct request_queue *q = rq->q; if (unlikely(blk_should_fake_timeout(q))) return; - if (!blk_mark_rq_complete(rq)) + if (!blk_mark_rq_complete(rq)) { + rq->errors = error; __blk_mq_complete_request(rq); + } } EXPORT_SYMBOL(blk_mq_complete_request); @@ -617,10 +619,8 @@ static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx, * If a request wasn't started before the queue was * marked dying, kill it here or it'll go unnoticed. */ - if (unlikely(blk_queue_dying(rq->q))) { - rq->errors = -EIO; - blk_mq_complete_request(rq); - } + if (unlikely(blk_queue_dying(rq->q))) + blk_mq_complete_request(rq, -EIO); return; } if (rq->cmd_flags & REQ_NO_TIMEOUT) @@ -642,24 +642,16 @@ static void blk_mq_rq_timer(unsigned long priv) .next = 0, .next_set = 0, }; - struct blk_mq_hw_ctx *hctx; int i; - queue_for_each_hw_ctx(q, hctx, i) { - /* - * If not software queues are currently mapped to this - * hardware queue, there's nothing to check - */ - if (!blk_mq_hw_queue_mapped(hctx)) - continue; - - blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data); - } + blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data); if (data.next_set) { data.next = blk_rq_timeout(round_jiffies_up(data.next)); mod_timer(&q->timeout, data.next); } else { + struct blk_mq_hw_ctx *hctx; + queue_for_each_hw_ctx(q, hctx, i) { /* the hctx may be unmapped, so check it here */ if (blk_mq_hw_queue_mapped(hctx)) @@ -1800,13 +1792,19 @@ static void blk_mq_init_cpu_queues(struct request_queue *q, } } -static void blk_mq_map_swqueue(struct request_queue *q) +static void blk_mq_map_swqueue(struct request_queue *q, + const struct cpumask *online_mask) { unsigned int i; struct blk_mq_hw_ctx *hctx; struct blk_mq_ctx *ctx; struct blk_mq_tag_set *set = q->tag_set; + /* + * Avoid others reading imcomplete hctx->cpumask through sysfs + */ + mutex_lock(&q->sysfs_lock); + queue_for_each_hw_ctx(q, hctx, i) { cpumask_clear(hctx->cpumask); hctx->nr_ctx = 0; @@ -1817,16 +1815,17 @@ static void blk_mq_map_swqueue(struct request_queue *q) */ queue_for_each_ctx(q, ctx, i) { /* If the cpu isn't online, the cpu is mapped to first hctx */ - if (!cpu_online(i)) + if (!cpumask_test_cpu(i, online_mask)) continue; hctx = q->mq_ops->map_queue(q, i); cpumask_set_cpu(i, hctx->cpumask); - cpumask_set_cpu(i, hctx->tags->cpumask); ctx->index_hw = hctx->nr_ctx; hctx->ctxs[hctx->nr_ctx++] = ctx; } + mutex_unlock(&q->sysfs_lock); + queue_for_each_hw_ctx(q, hctx, i) { struct blk_mq_ctxmap *map = &hctx->ctx_map; @@ -1862,6 +1861,14 @@ static void blk_mq_map_swqueue(struct request_queue *q) hctx->next_cpu = cpumask_first(hctx->cpumask); hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH; } + + queue_for_each_ctx(q, ctx, i) { + if (!cpumask_test_cpu(i, online_mask)) + continue; + + hctx = q->mq_ops->map_queue(q, i); + cpumask_set_cpu(i, hctx->tags->cpumask); + } } static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set) @@ -1929,6 +1936,9 @@ void blk_mq_release(struct request_queue *q) kfree(hctx); } + kfree(q->mq_map); + q->mq_map = NULL; + kfree(q->queue_hw_ctx); /* ctx kobj stays in queue_ctx */ @@ -2038,13 +2048,15 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set, if (blk_mq_init_hw_queues(q, set)) goto err_hctxs; + get_online_cpus(); mutex_lock(&all_q_mutex); - list_add_tail(&q->all_q_node, &all_q_list); - mutex_unlock(&all_q_mutex); + list_add_tail(&q->all_q_node, &all_q_list); blk_mq_add_queue_tag_set(set, q); + blk_mq_map_swqueue(q, cpu_online_mask); - blk_mq_map_swqueue(q); + mutex_unlock(&all_q_mutex); + put_online_cpus(); return q; @@ -2068,30 +2080,27 @@ void blk_mq_free_queue(struct request_queue *q) { struct blk_mq_tag_set *set = q->tag_set; + mutex_lock(&all_q_mutex); + list_del_init(&q->all_q_node); + mutex_unlock(&all_q_mutex); + blk_mq_del_queue_tag_set(q); blk_mq_exit_hw_queues(q, set, set->nr_hw_queues); blk_mq_free_hw_queues(q, set); percpu_ref_exit(&q->mq_usage_counter); - - kfree(q->mq_map); - - q->mq_map = NULL; - - mutex_lock(&all_q_mutex); - list_del_init(&q->all_q_node); - mutex_unlock(&all_q_mutex); } /* Basically redo blk_mq_init_queue with queue frozen */ -static void blk_mq_queue_reinit(struct request_queue *q) +static void blk_mq_queue_reinit(struct request_queue *q, + const struct cpumask *online_mask) { WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth)); blk_mq_sysfs_unregister(q); - blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues); + blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues, online_mask); /* * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe @@ -2099,7 +2108,7 @@ static void blk_mq_queue_reinit(struct request_queue *q) * involves free and re-allocate memory, worthy doing?) */ - blk_mq_map_swqueue(q); + blk_mq_map_swqueue(q, online_mask); blk_mq_sysfs_register(q); } @@ -2108,16 +2117,43 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, unsigned long action, void *hcpu) { struct request_queue *q; + int cpu = (unsigned long)hcpu; + /* + * New online cpumask which is going to be set in this hotplug event. + * Declare this cpumasks as global as cpu-hotplug operation is invoked + * one-by-one and dynamically allocating this could result in a failure. + */ + static struct cpumask online_new; /* - * Before new mappings are established, hotadded cpu might already - * start handling requests. This doesn't break anything as we map - * offline CPUs to first hardware queue. We will re-init the queue - * below to get optimal settings. + * Before hotadded cpu starts handling requests, new mappings must + * be established. Otherwise, these requests in hw queue might + * never be dispatched. + * + * For example, there is a single hw queue (hctx) and two CPU queues + * (ctx0 for CPU0, and ctx1 for CPU1). + * + * Now CPU1 is just onlined and a request is inserted into + * ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is + * still zero. + * + * And then while running hw queue, flush_busy_ctxs() finds bit0 is + * set in pending bitmap and tries to retrieve requests in + * hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0, + * so the request in ctx1->rq_list is ignored. */ - if (action != CPU_DEAD && action != CPU_DEAD_FROZEN && - action != CPU_ONLINE && action != CPU_ONLINE_FROZEN) + switch (action & ~CPU_TASKS_FROZEN) { + case CPU_DEAD: + case CPU_UP_CANCELED: + cpumask_copy(&online_new, cpu_online_mask); + break; + case CPU_UP_PREPARE: + cpumask_copy(&online_new, cpu_online_mask); + cpumask_set_cpu(cpu, &online_new); + break; + default: return NOTIFY_OK; + } mutex_lock(&all_q_mutex); @@ -2141,7 +2177,7 @@ static int blk_mq_queue_reinit_notify(struct notifier_block *nb, } list_for_each_entry(q, &all_q_list, all_q_node) - blk_mq_queue_reinit(q); + blk_mq_queue_reinit(q, &online_new); list_for_each_entry(q, &all_q_list, all_q_node) blk_mq_unfreeze_queue(q); |