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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /block/blk-mq.c
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c125
1 files changed, 78 insertions, 47 deletions
diff --git a/block/blk-mq.c b/block/blk-mq.c
index c69902695..85f014327 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -393,14 +393,16 @@ 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);
@@ -616,10 +618,8 @@ 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)
@@ -641,24 +641,16 @@ 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))
@@ -1185,7 +1177,7 @@ static struct request *blk_mq_map_request(struct request_queue *q,
struct blk_mq_alloc_data alloc_data;
if (unlikely(blk_mq_queue_enter(q, GFP_KERNEL))) {
- bio_endio(bio, -EIO);
+ bio_io_error(bio);
return NULL;
}
@@ -1269,10 +1261,12 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
blk_queue_bounce(q, &bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
- bio_endio(bio, -EIO);
+ bio_io_error(bio);
return;
}
+ blk_queue_split(q, &bio, q->bio_split);
+
if (!is_flush_fua && !blk_queue_nomerges(q) &&
blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
return;
@@ -1354,10 +1348,12 @@ static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
blk_queue_bounce(q, &bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
- bio_endio(bio, -EIO);
+ bio_io_error(bio);
return;
}
+ blk_queue_split(q, &bio, q->bio_split);
+
if (!is_flush_fua && !blk_queue_nomerges(q) &&
blk_attempt_plug_merge(q, bio, &request_count, NULL))
return;
@@ -1785,13 +1781,19 @@ 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;
@@ -1802,7 +1804,7 @@ 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);
@@ -1811,6 +1813,8 @@ static void blk_mq_map_swqueue(struct request_queue *q)
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;
@@ -1848,7 +1852,7 @@ static void blk_mq_map_swqueue(struct request_queue *q)
}
queue_for_each_ctx(q, ctx, i) {
- if (!cpu_online(i))
+ if (!cpumask_test_cpu(i, online_mask))
continue;
hctx = q->mq_ops->map_queue(q, i);
@@ -1921,6 +1925,9 @@ 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 */
@@ -2030,13 +2037,15 @@ 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;
@@ -2060,30 +2069,27 @@ 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
@@ -2091,7 +2097,7 @@ 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);
}
@@ -2100,16 +2106,43 @@ 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);
@@ -2133,7 +2166,7 @@ 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);
@@ -2263,10 +2296,8 @@ void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
int i;
for (i = 0; i < set->nr_hw_queues; i++) {
- if (set->tags[i]) {
+ if (set->tags[i])
blk_mq_free_rq_map(set, set->tags[i], i);
- free_cpumask_var(set->tags[i]->cpumask);
- }
}
kfree(set->tags);