#include <linux/sched/sysctl.h>
#include <linux/delay.h>
#include <linux/crash_dump.h>
+#include <linux/prefetch.h>
#include <trace/events/block.h>
static void blk_mq_requeue_work(struct work_struct *work)
{
struct request_queue *q =
- container_of(work, struct request_queue, requeue_work);
+ container_of(work, struct request_queue, requeue_work.work);
LIST_HEAD(rq_list);
struct request *rq, *next;
unsigned long flags;
void blk_mq_cancel_requeue_work(struct request_queue *q)
{
- cancel_work_sync(&q->requeue_work);
+ cancel_delayed_work_sync(&q->requeue_work);
}
EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work);
void blk_mq_kick_requeue_list(struct request_queue *q)
{
- kblockd_schedule_work(&q->requeue_work);
+ kblockd_schedule_delayed_work(&q->requeue_work, 0);
}
EXPORT_SYMBOL(blk_mq_kick_requeue_list);
+void blk_mq_delay_kick_requeue_list(struct request_queue *q,
+ unsigned long msecs)
+{
+ kblockd_schedule_delayed_work(&q->requeue_work,
+ msecs_to_jiffies(msecs));
+}
+EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
+
void blk_mq_abort_requeue_list(struct request_queue *q)
{
unsigned long flags;
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
{
- if (tag < tags->nr_tags)
+ if (tag < tags->nr_tags) {
+ prefetch(tags->rqs[tag]);
return tags->rqs[tag];
+ }
return NULL;
}
};
int i;
- if (blk_queue_enter(q, true))
+ /* A deadlock might occur if a request is stuck requiring a
+ * timeout at the same time a queue freeze is waiting
+ * completion, since the timeout code would not be able to
+ * acquire the queue reference here.
+ *
+ * That's why we don't use blk_queue_enter here; instead, we use
+ * percpu_ref_tryget directly, because we need to be able to
+ * obtain a reference even in the short window between the queue
+ * starting to freeze, by dropping the first reference in
+ * blk_mq_freeze_queue_start, and the moment the last request is
+ * consumed, marked by the instant q_usage_counter reaches
+ * zero.
+ */
+ if (!percpu_ref_tryget(&q->q_usage_counter))
return;
blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);
struct list_head *dptr;
int queued;
- WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask));
-
if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
return;
+ WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
+ cpu_online(hctx->next_cpu));
+
hctx->run++;
/*
put_cpu();
}
- kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
- &hctx->run_work, 0);
+ kblockd_schedule_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work);
}
void blk_mq_run_hw_queues(struct request_queue *q, bool async)
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
{
- cancel_delayed_work(&hctx->run_work);
+ cancel_work(&hctx->run_work);
cancel_delayed_work(&hctx->delay_work);
set_bit(BLK_MQ_S_STOPPED, &hctx->state);
}
{
struct blk_mq_hw_ctx *hctx;
- hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
+ hctx = container_of(work, struct blk_mq_hw_ctx, run_work);
__blk_mq_run_hw_queue(hctx);
}
EXPORT_SYMBOL(blk_mq_delay_queue);
static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx,
struct request *rq,
bool at_head)
{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+
trace_block_rq_insert(hctx->queue, rq);
if (at_head)
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
- __blk_mq_insert_req_list(hctx, ctx, rq, at_head);
+ __blk_mq_insert_req_list(hctx, rq, at_head);
blk_mq_hctx_mark_pending(hctx, ctx);
}
void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
- bool async)
+ bool async)
{
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
struct request_queue *q = rq->q;
struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx;
-
- current_ctx = blk_mq_get_ctx(q);
- if (!cpu_online(ctx->cpu))
- rq->mq_ctx = ctx = current_ctx;
hctx = q->mq_ops->map_queue(q, ctx->cpu);
if (run_queue)
blk_mq_run_hw_queue(hctx, async);
-
- blk_mq_put_ctx(current_ctx);
}
static void blk_mq_insert_requests(struct request_queue *q,
{
struct blk_mq_hw_ctx *hctx;
- struct blk_mq_ctx *current_ctx;
trace_block_unplug(q, depth, !from_schedule);
- current_ctx = blk_mq_get_ctx(q);
-
- if (!cpu_online(ctx->cpu))
- ctx = current_ctx;
hctx = q->mq_ops->map_queue(q, ctx->cpu);
/*
struct request *rq;
rq = list_first_entry(list, struct request, queuelist);
+ BUG_ON(rq->mq_ctx != ctx);
list_del_init(&rq->queuelist);
- rq->mq_ctx = ctx;
- __blk_mq_insert_req_list(hctx, ctx, rq, false);
+ __blk_mq_insert_req_list(hctx, rq, false);
}
blk_mq_hctx_mark_pending(hctx, ctx);
spin_unlock(&ctx->lock);
blk_mq_run_hw_queue(hctx, from_schedule);
- blk_mq_put_ctx(current_ctx);
}
static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
ctx = blk_mq_get_ctx(q);
hctx = q->mq_ops->map_queue(q, ctx->cpu);
- if (rw_is_sync(bio_op(bio), bio->bi_rw))
+ if (rw_is_sync(bio_op(bio), bio->bi_opf))
op_flags |= REQ_SYNC;
trace_block_getrq(q, bio, op);
*/
static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
{
- const int is_sync = rw_is_sync(bio_op(bio), bio->bi_rw);
- const int is_flush_fua = bio->bi_rw & (REQ_PREFLUSH | REQ_FUA);
+ const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
+ const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
struct blk_map_ctx data;
struct request *rq;
unsigned int request_count = 0;
*/
static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
{
- const int is_sync = rw_is_sync(bio_op(bio), bio->bi_rw);
- const int is_flush_fua = bio->bi_rw & (REQ_PREFLUSH | REQ_FUA);
+ const int is_sync = rw_is_sync(bio_op(bio), bio->bi_opf);
+ const int is_flush_fua = bio->bi_opf & (REQ_PREFLUSH | REQ_FUA);
struct blk_plug *plug;
unsigned int request_count = 0;
struct blk_map_ctx data;
return 0;
}
+/*
+ * 'cpu' is going away. splice any existing rq_list entries from this
+ * software queue to the hw queue dispatch list, and ensure that it
+ * gets run.
+ */
static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu)
{
- struct request_queue *q = hctx->queue;
struct blk_mq_ctx *ctx;
LIST_HEAD(tmp);
- /*
- * Move ctx entries to new CPU, if this one is going away.
- */
- ctx = __blk_mq_get_ctx(q, cpu);
+ ctx = __blk_mq_get_ctx(hctx->queue, cpu);
spin_lock(&ctx->lock);
if (!list_empty(&ctx->rq_list)) {
if (list_empty(&tmp))
return NOTIFY_OK;
- ctx = blk_mq_get_ctx(q);
- spin_lock(&ctx->lock);
-
- while (!list_empty(&tmp)) {
- struct request *rq;
-
- rq = list_first_entry(&tmp, struct request, queuelist);
- rq->mq_ctx = ctx;
- list_move_tail(&rq->queuelist, &ctx->rq_list);
- }
-
- hctx = q->mq_ops->map_queue(q, ctx->cpu);
- blk_mq_hctx_mark_pending(hctx, ctx);
-
- spin_unlock(&ctx->lock);
+ spin_lock(&hctx->lock);
+ list_splice_tail_init(&tmp, &hctx->dispatch);
+ spin_unlock(&hctx->lock);
blk_mq_run_hw_queue(hctx, true);
- blk_mq_put_ctx(ctx);
return NOTIFY_OK;
}
if (node == NUMA_NO_NODE)
node = hctx->numa_node = set->numa_node;
- INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
+ INIT_WORK(&hctx->run_work, blk_mq_run_work_fn);
INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
spin_lock_init(&hctx->lock);
INIT_LIST_HEAD(&hctx->dispatch);
q->sg_reserved_size = INT_MAX;
- INIT_WORK(&q->requeue_work, blk_mq_requeue_work);
+ INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
INIT_LIST_HEAD(&q->requeue_list);
spin_lock_init(&q->requeue_lock);