static void blk_mq_poll_stats_start(struct request_queue *q);
static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
-static void __blk_mq_stop_hw_queues(struct request_queue *q, bool sync);
static int blk_mq_poll_stats_bkt(const struct request *rq)
{
}
EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
+/*
+ * FIXME: replace the scsi_internal_device_*block_nowait() calls in the
+ * mpt3sas driver such that this function can be removed.
+ */
+void blk_mq_quiesce_queue_nowait(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ queue_flag_set(QUEUE_FLAG_QUIESCED, q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+}
+EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);
+
/**
- * blk_mq_quiesce_queue() - wait until all ongoing queue_rq calls have finished
+ * blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished
* @q: request queue.
*
* Note: this function does not prevent that the struct request end_io()
- * callback function is invoked. Additionally, it is not prevented that
- * new queue_rq() calls occur unless the queue has been stopped first.
+ * callback function is invoked. Once this function is returned, we make
+ * sure no dispatch can happen until the queue is unquiesced via
+ * blk_mq_unquiesce_queue().
*/
void blk_mq_quiesce_queue(struct request_queue *q)
{
unsigned int i;
bool rcu = false;
- __blk_mq_stop_hw_queues(q, true);
+ blk_mq_quiesce_queue_nowait(q);
queue_for_each_hw_ctx(q, hctx, i) {
if (hctx->flags & BLK_MQ_F_BLOCKING)
- synchronize_srcu(&hctx->queue_rq_srcu);
+ synchronize_srcu(hctx->queue_rq_srcu);
else
rcu = true;
}
}
EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
+/*
+ * blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue()
+ * @q: request queue.
+ *
+ * This function recovers queue into the state before quiescing
+ * which is done by blk_mq_quiesce_queue.
+ */
+void blk_mq_unquiesce_queue(struct request_queue *q)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(q->queue_lock, flags);
+ queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
+ spin_unlock_irqrestore(q->queue_lock, flags);
+
+ /* dispatch requests which are inserted during quiescing */
+ blk_mq_run_hw_queues(q, true);
+}
+EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
+
void blk_mq_wake_waiters(struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
}
EXPORT_SYMBOL(blk_mq_can_queue);
-void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
- struct request *rq, unsigned int op)
+static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
+ unsigned int tag, unsigned int op)
{
+ struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
+ struct request *rq = tags->static_rqs[tag];
+
+ rq->rq_flags = 0;
+
+ if (data->flags & BLK_MQ_REQ_INTERNAL) {
+ rq->tag = -1;
+ rq->internal_tag = tag;
+ } else {
+ if (blk_mq_tag_busy(data->hctx)) {
+ rq->rq_flags = RQF_MQ_INFLIGHT;
+ atomic_inc(&data->hctx->nr_active);
+ }
+ rq->tag = tag;
+ rq->internal_tag = -1;
+ data->hctx->tags->rqs[rq->tag] = rq;
+ }
+
INIT_LIST_HEAD(&rq->queuelist);
/* csd/requeue_work/fifo_time is initialized before use */
- rq->q = q;
- rq->mq_ctx = ctx;
+ rq->q = data->q;
+ rq->mq_ctx = data->ctx;
rq->cmd_flags = op;
- if (blk_queue_io_stat(q))
+ if (blk_queue_io_stat(data->q))
rq->rq_flags |= RQF_IO_STAT;
/* do not touch atomic flags, it needs atomic ops against the timer */
rq->cpu = -1;
rq->end_io_data = NULL;
rq->next_rq = NULL;
- ctx->rq_dispatched[op_is_sync(op)]++;
+ data->ctx->rq_dispatched[op_is_sync(op)]++;
+ return rq;
}
-EXPORT_SYMBOL_GPL(blk_mq_rq_ctx_init);
-struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data,
- unsigned int op)
+static struct request *blk_mq_get_request(struct request_queue *q,
+ struct bio *bio, unsigned int op,
+ struct blk_mq_alloc_data *data)
{
+ struct elevator_queue *e = q->elevator;
struct request *rq;
unsigned int tag;
- tag = blk_mq_get_tag(data);
- if (tag != BLK_MQ_TAG_FAIL) {
- struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
+ blk_queue_enter_live(q);
+ data->q = q;
+ if (likely(!data->ctx))
+ data->ctx = blk_mq_get_ctx(q);
+ if (likely(!data->hctx))
+ data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
+ if (op & REQ_NOWAIT)
+ data->flags |= BLK_MQ_REQ_NOWAIT;
- rq = tags->static_rqs[tag];
+ if (e) {
+ data->flags |= BLK_MQ_REQ_INTERNAL;
- if (data->flags & BLK_MQ_REQ_INTERNAL) {
- rq->tag = -1;
- rq->internal_tag = tag;
- } else {
- if (blk_mq_tag_busy(data->hctx)) {
- rq->rq_flags = RQF_MQ_INFLIGHT;
- atomic_inc(&data->hctx->nr_active);
- }
- rq->tag = tag;
- rq->internal_tag = -1;
- data->hctx->tags->rqs[rq->tag] = rq;
- }
+ /*
+ * Flush requests are special and go directly to the
+ * dispatch list.
+ */
+ if (!op_is_flush(op) && e->type->ops.mq.limit_depth)
+ e->type->ops.mq.limit_depth(op, data);
+ }
- blk_mq_rq_ctx_init(data->q, data->ctx, rq, op);
- return rq;
+ tag = blk_mq_get_tag(data);
+ if (tag == BLK_MQ_TAG_FAIL) {
+ blk_queue_exit(q);
+ return NULL;
}
- return NULL;
+ rq = blk_mq_rq_ctx_init(data, tag, op);
+ if (!op_is_flush(op)) {
+ rq->elv.icq = NULL;
+ if (e && e->type->ops.mq.prepare_request) {
+ if (e->type->icq_cache && rq_ioc(bio))
+ blk_mq_sched_assign_ioc(rq, bio);
+
+ e->type->ops.mq.prepare_request(rq, bio);
+ rq->rq_flags |= RQF_ELVPRIV;
+ }
+ }
+ data->hctx->queued++;
+ return rq;
}
-EXPORT_SYMBOL_GPL(__blk_mq_alloc_request);
-struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
+struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
unsigned int flags)
{
struct blk_mq_alloc_data alloc_data = { .flags = flags };
if (ret)
return ERR_PTR(ret);
- rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data);
+ rq = blk_mq_get_request(q, NULL, op, &alloc_data);
blk_mq_put_ctx(alloc_data.ctx);
blk_queue_exit(q);
}
EXPORT_SYMBOL(blk_mq_alloc_request);
-struct request *blk_mq_alloc_request_hctx(struct request_queue *q, int rw,
- unsigned int flags, unsigned int hctx_idx)
+struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
+ unsigned int op, unsigned int flags, unsigned int hctx_idx)
{
struct blk_mq_alloc_data alloc_data = { .flags = flags };
struct request *rq;
cpu = cpumask_first(alloc_data.hctx->cpumask);
alloc_data.ctx = __blk_mq_get_ctx(q, cpu);
- rq = blk_mq_sched_get_request(q, NULL, rw, &alloc_data);
+ rq = blk_mq_get_request(q, NULL, op, &alloc_data);
blk_queue_exit(q);
}
EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
-void __blk_mq_finish_request(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
- struct request *rq)
+void blk_mq_free_request(struct request *rq)
{
- const int sched_tag = rq->internal_tag;
struct request_queue *q = rq->q;
+ struct elevator_queue *e = q->elevator;
+ struct blk_mq_ctx *ctx = rq->mq_ctx;
+ struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
+ const int sched_tag = rq->internal_tag;
+ if (rq->rq_flags & RQF_ELVPRIV) {
+ if (e && e->type->ops.mq.finish_request)
+ e->type->ops.mq.finish_request(rq);
+ if (rq->elv.icq) {
+ put_io_context(rq->elv.icq->ioc);
+ rq->elv.icq = NULL;
+ }
+ }
+
+ ctx->rq_completed[rq_is_sync(rq)]++;
if (rq->rq_flags & RQF_MQ_INFLIGHT)
atomic_dec(&hctx->nr_active);
wbt_done(q->rq_wb, &rq->issue_stat);
- rq->rq_flags = 0;
clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
clear_bit(REQ_ATOM_POLL_SLEPT, &rq->atomic_flags);
blk_mq_sched_restart(hctx);
blk_queue_exit(q);
}
-
-static void blk_mq_finish_hctx_request(struct blk_mq_hw_ctx *hctx,
- struct request *rq)
-{
- struct blk_mq_ctx *ctx = rq->mq_ctx;
-
- ctx->rq_completed[rq_is_sync(rq)]++;
- __blk_mq_finish_request(hctx, ctx, rq);
-}
-
-void blk_mq_finish_request(struct request *rq)
-{
- blk_mq_finish_hctx_request(blk_mq_map_queue(rq->q, rq->mq_ctx->cpu), rq);
-}
-EXPORT_SYMBOL_GPL(blk_mq_finish_request);
-
-void blk_mq_free_request(struct request *rq)
-{
- blk_mq_sched_put_request(rq);
-}
EXPORT_SYMBOL_GPL(blk_mq_free_request);
-inline void __blk_mq_end_request(struct request *rq, int error)
+inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
{
blk_account_io_done(rq);
}
EXPORT_SYMBOL(__blk_mq_end_request);
-void blk_mq_end_request(struct request *rq, int error)
+void blk_mq_end_request(struct request *rq, blk_status_t error)
{
if (blk_update_request(rq, error, blk_rq_bytes(rq)))
BUG();
blk_queue_exit(q);
}
-/*
- * Reverse check our software queue for entries that we could potentially
- * merge with. Currently includes a hand-wavy stop count of 8, to not spend
- * too much time checking for merges.
- */
-static bool blk_mq_attempt_merge(struct request_queue *q,
- struct blk_mq_ctx *ctx, struct bio *bio)
-{
- struct request *rq;
- int checked = 8;
-
- list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
- bool merged = false;
-
- if (!checked--)
- break;
-
- if (!blk_rq_merge_ok(rq, bio))
- continue;
-
- switch (blk_try_merge(rq, bio)) {
- case ELEVATOR_BACK_MERGE:
- if (blk_mq_sched_allow_merge(q, rq, bio))
- merged = bio_attempt_back_merge(q, rq, bio);
- break;
- case ELEVATOR_FRONT_MERGE:
- if (blk_mq_sched_allow_merge(q, rq, bio))
- merged = bio_attempt_front_merge(q, rq, bio);
- break;
- case ELEVATOR_DISCARD_MERGE:
- merged = bio_attempt_discard_merge(q, rq, bio);
- break;
- default:
- continue;
- }
-
- if (merged)
- ctx->rq_merged++;
- return merged;
- }
-
- return false;
-}
-
struct flush_busy_ctx_data {
struct blk_mq_hw_ctx *hctx;
struct list_head *list;
{
struct blk_mq_hw_ctx *hctx;
struct request *rq;
- int errors, queued, ret = BLK_MQ_RQ_QUEUE_OK;
+ int errors, queued;
if (list_empty(list))
return false;
errors = queued = 0;
do {
struct blk_mq_queue_data bd;
+ blk_status_t ret;
rq = list_first_entry(list, struct request, queuelist);
if (!blk_mq_get_driver_tag(rq, &hctx, false)) {
}
ret = q->mq_ops->queue_rq(hctx, &bd);
- switch (ret) {
- case BLK_MQ_RQ_QUEUE_OK:
- queued++;
- break;
- case BLK_MQ_RQ_QUEUE_BUSY:
+ if (ret == BLK_STS_RESOURCE) {
blk_mq_put_driver_tag_hctx(hctx, rq);
list_add(&rq->queuelist, list);
__blk_mq_requeue_request(rq);
break;
- default:
- pr_err("blk-mq: bad return on queue: %d\n", ret);
- case BLK_MQ_RQ_QUEUE_ERROR:
+ }
+
+ if (unlikely(ret != BLK_STS_OK)) {
errors++;
- blk_mq_end_request(rq, -EIO);
- break;
+ blk_mq_end_request(rq, BLK_STS_IOERR);
+ continue;
}
- if (ret == BLK_MQ_RQ_QUEUE_BUSY)
- break;
+ queued++;
} while (!list_empty(list));
hctx->dispatched[queued_to_index(queued)]++;
* - blk_mq_run_hw_queue() checks whether or not a queue has
* been stopped before rerunning a queue.
* - Some but not all block drivers stop a queue before
- * returning BLK_MQ_RQ_QUEUE_BUSY. Two exceptions are scsi-mq
+ * returning BLK_STS_RESOURCE. Two exceptions are scsi-mq
* and dm-rq.
*/
if (!blk_mq_sched_needs_restart(hctx) &&
} else {
might_sleep();
- srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);
+ srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
blk_mq_sched_dispatch_requests(hctx);
- srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);
+ srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
}
}
static void __blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async,
unsigned long msecs)
{
- if (unlikely(blk_mq_hctx_stopped(hctx) ||
- !blk_mq_hw_queue_mapped(hctx)))
+ if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx)))
+ return;
+
+ if (unlikely(blk_mq_hctx_stopped(hctx)))
return;
if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
}
EXPORT_SYMBOL(blk_mq_queue_stopped);
-static void __blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx, bool sync)
+/*
+ * This function is often used for pausing .queue_rq() by driver when
+ * there isn't enough resource or some conditions aren't satisfied, and
+ * BLK_MQ_RQ_QUEUE_BUSY is usually returned.
+ *
+ * We do not guarantee that dispatch can be drained or blocked
+ * after blk_mq_stop_hw_queue() returns. Please use
+ * blk_mq_quiesce_queue() for that requirement.
+ */
+void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
{
- if (sync)
- cancel_delayed_work_sync(&hctx->run_work);
- else
- cancel_delayed_work(&hctx->run_work);
+ cancel_delayed_work(&hctx->run_work);
set_bit(BLK_MQ_S_STOPPED, &hctx->state);
}
-
-void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
-{
- __blk_mq_stop_hw_queue(hctx, false);
-}
EXPORT_SYMBOL(blk_mq_stop_hw_queue);
-static void __blk_mq_stop_hw_queues(struct request_queue *q, bool sync)
+/*
+ * This function is often used for pausing .queue_rq() by driver when
+ * there isn't enough resource or some conditions aren't satisfied, and
+ * BLK_MQ_RQ_QUEUE_BUSY is usually returned.
+ *
+ * We do not guarantee that dispatch can be drained or blocked
+ * after blk_mq_stop_hw_queues() returns. Please use
+ * blk_mq_quiesce_queue() for that requirement.
+ */
+void blk_mq_stop_hw_queues(struct request_queue *q)
{
struct blk_mq_hw_ctx *hctx;
int i;
queue_for_each_hw_ctx(q, hctx, i)
- __blk_mq_stop_hw_queue(hctx, sync);
-}
-
-void blk_mq_stop_hw_queues(struct request_queue *q)
-{
- __blk_mq_stop_hw_queues(q, false);
+ blk_mq_stop_hw_queue(hctx);
}
EXPORT_SYMBOL(blk_mq_stop_hw_queues);
void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
{
- if (unlikely(!blk_mq_hw_queue_mapped(hctx)))
+ if (WARN_ON_ONCE(!blk_mq_hw_queue_mapped(hctx)))
return;
/*
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
+ lockdep_assert_held(&ctx->lock);
+
trace_block_rq_insert(hctx->queue, rq);
if (at_head)
{
struct blk_mq_ctx *ctx = rq->mq_ctx;
+ lockdep_assert_held(&ctx->lock);
+
__blk_mq_insert_req_list(hctx, rq, at_head);
blk_mq_hctx_mark_pending(hctx, ctx);
}
!blk_queue_nomerges(hctx->queue);
}
-static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
- struct blk_mq_ctx *ctx,
- struct request *rq, struct bio *bio)
+static inline void blk_mq_queue_io(struct blk_mq_hw_ctx *hctx,
+ struct blk_mq_ctx *ctx,
+ struct request *rq)
{
- if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
- blk_mq_bio_to_request(rq, bio);
- spin_lock(&ctx->lock);
-insert_rq:
- __blk_mq_insert_request(hctx, rq, false);
- spin_unlock(&ctx->lock);
- return false;
- } else {
- struct request_queue *q = hctx->queue;
-
- spin_lock(&ctx->lock);
- if (!blk_mq_attempt_merge(q, ctx, bio)) {
- blk_mq_bio_to_request(rq, bio);
- goto insert_rq;
- }
-
- spin_unlock(&ctx->lock);
- __blk_mq_finish_request(hctx, ctx, rq);
- return true;
- }
+ spin_lock(&ctx->lock);
+ __blk_mq_insert_request(hctx, rq, false);
+ spin_unlock(&ctx->lock);
}
static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq)
.last = true,
};
blk_qc_t new_cookie;
- int ret;
+ blk_status_t ret;
bool run_queue = true;
- if (blk_mq_hctx_stopped(hctx)) {
+ /* RCU or SRCU read lock is needed before checking quiesced flag */
+ if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) {
run_queue = false;
goto insert;
}
* would have done
*/
ret = q->mq_ops->queue_rq(hctx, &bd);
- if (ret == BLK_MQ_RQ_QUEUE_OK) {
+ switch (ret) {
+ case BLK_STS_OK:
*cookie = new_cookie;
return;
- }
-
- if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
+ case BLK_STS_RESOURCE:
+ __blk_mq_requeue_request(rq);
+ goto insert;
+ default:
*cookie = BLK_QC_T_NONE;
- blk_mq_end_request(rq, -EIO);
+ blk_mq_end_request(rq, ret);
return;
}
- __blk_mq_requeue_request(rq);
insert:
blk_mq_sched_insert_request(rq, false, run_queue, false, may_sleep);
}
might_sleep();
- srcu_idx = srcu_read_lock(&hctx->queue_rq_srcu);
+ srcu_idx = srcu_read_lock(hctx->queue_rq_srcu);
__blk_mq_try_issue_directly(hctx, rq, cookie, true);
- srcu_read_unlock(&hctx->queue_rq_srcu, srcu_idx);
+ srcu_read_unlock(hctx->queue_rq_srcu, srcu_idx);
}
}
blk_queue_bounce(q, &bio);
- blk_queue_split(q, &bio, q->bio_split);
+ blk_queue_split(q, &bio);
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
bio_io_error(bio);
trace_block_getrq(q, bio, bio->bi_opf);
- rq = blk_mq_sched_get_request(q, bio, bio->bi_opf, &data);
+ rq = blk_mq_get_request(q, bio, bio->bi_opf, &data);
if (unlikely(!rq)) {
__wbt_done(q->rq_wb, wb_acct);
+ if (bio->bi_opf & REQ_NOWAIT)
+ bio_wouldblock_error(bio);
return BLK_QC_T_NONE;
}
blk_mq_put_ctx(data.ctx);
blk_mq_bio_to_request(rq, bio);
blk_mq_sched_insert_request(rq, false, true, true, true);
- } else if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
+ } else {
blk_mq_put_ctx(data.ctx);
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_queue_io(data.hctx, data.ctx, rq);
blk_mq_run_hw_queue(data.hctx, true);
- } else
- blk_mq_put_ctx(data.ctx);
+ }
return cookie;
}
set->ops->exit_hctx(hctx, hctx_idx);
if (hctx->flags & BLK_MQ_F_BLOCKING)
- cleanup_srcu_struct(&hctx->queue_rq_srcu);
+ cleanup_srcu_struct(hctx->queue_rq_srcu);
blk_mq_remove_cpuhp(hctx);
blk_free_flush_queue(hctx->fq);
goto free_fq;
if (hctx->flags & BLK_MQ_F_BLOCKING)
- init_srcu_struct(&hctx->queue_rq_srcu);
+ init_srcu_struct(hctx->queue_rq_srcu);
blk_mq_debugfs_register_hctx(q, hctx);
}
EXPORT_SYMBOL(blk_mq_init_queue);
+static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set)
+{
+ int hw_ctx_size = sizeof(struct blk_mq_hw_ctx);
+
+ BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, queue_rq_srcu),
+ __alignof__(struct blk_mq_hw_ctx)) !=
+ sizeof(struct blk_mq_hw_ctx));
+
+ if (tag_set->flags & BLK_MQ_F_BLOCKING)
+ hw_ctx_size += sizeof(struct srcu_struct);
+
+ return hw_ctx_size;
+}
+
static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
struct request_queue *q)
{
continue;
node = blk_mq_hw_queue_to_node(q->mq_map, i);
- hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
+ hctxs[i] = kzalloc_node(blk_mq_hw_ctx_size(set),
GFP_KERNEL, node);
if (!hctxs[i])
break;
projects / karo-tx-linux.git / blobdiff