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![Yu Kuai](/assets/img/avatar_default.png)
If blk_mq_request_issue_directly() failed from blk_insert_cloned_request(), the request will be accounted start. Currently, blk_insert_cloned_request() is only called by dm, and such request won't be accounted done by dm. In normal path, io will be accounted start from blk_mq_bio_to_request(), when the request is allocated, and such io will be accounted done from __blk_mq_end_request_acct() whether it succeeded or failed. Thus add blk_account_io_done() to fix the problem. Signed-off-by: Yu Kuai <yukuai3@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20220126012132.3111551-1-yukuai3@huawei.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
4759 lines
118 KiB
C
4759 lines
118 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Block multiqueue core code
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*
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* Copyright (C) 2013-2014 Jens Axboe
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* Copyright (C) 2013-2014 Christoph Hellwig
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/backing-dev.h>
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#include <linux/bio.h>
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#include <linux/blkdev.h>
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#include <linux/blk-integrity.h>
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#include <linux/kmemleak.h>
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/workqueue.h>
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#include <linux/smp.h>
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#include <linux/interrupt.h>
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#include <linux/llist.h>
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#include <linux/cpu.h>
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#include <linux/cache.h>
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#include <linux/sched/sysctl.h>
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#include <linux/sched/topology.h>
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#include <linux/sched/signal.h>
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#include <linux/delay.h>
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#include <linux/crash_dump.h>
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#include <linux/prefetch.h>
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#include <linux/blk-crypto.h>
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#include <linux/part_stat.h>
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#include <trace/events/block.h>
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#include <linux/blk-mq.h>
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#include <linux/t10-pi.h>
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#include "blk.h"
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#include "blk-mq.h"
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#include "blk-mq-debugfs.h"
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#include "blk-mq-tag.h"
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#include "blk-pm.h"
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#include "blk-stat.h"
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#include "blk-mq-sched.h"
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#include "blk-rq-qos.h"
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static DEFINE_PER_CPU(struct llist_head, blk_cpu_done);
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static void blk_mq_poll_stats_start(struct request_queue *q);
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static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb);
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static int blk_mq_poll_stats_bkt(const struct request *rq)
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{
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int ddir, sectors, bucket;
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ddir = rq_data_dir(rq);
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sectors = blk_rq_stats_sectors(rq);
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bucket = ddir + 2 * ilog2(sectors);
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if (bucket < 0)
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return -1;
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else if (bucket >= BLK_MQ_POLL_STATS_BKTS)
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return ddir + BLK_MQ_POLL_STATS_BKTS - 2;
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return bucket;
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}
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#define BLK_QC_T_SHIFT 16
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#define BLK_QC_T_INTERNAL (1U << 31)
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static inline struct blk_mq_hw_ctx *blk_qc_to_hctx(struct request_queue *q,
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blk_qc_t qc)
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{
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return q->queue_hw_ctx[(qc & ~BLK_QC_T_INTERNAL) >> BLK_QC_T_SHIFT];
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}
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static inline struct request *blk_qc_to_rq(struct blk_mq_hw_ctx *hctx,
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blk_qc_t qc)
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{
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unsigned int tag = qc & ((1U << BLK_QC_T_SHIFT) - 1);
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if (qc & BLK_QC_T_INTERNAL)
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return blk_mq_tag_to_rq(hctx->sched_tags, tag);
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return blk_mq_tag_to_rq(hctx->tags, tag);
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}
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static inline blk_qc_t blk_rq_to_qc(struct request *rq)
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{
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return (rq->mq_hctx->queue_num << BLK_QC_T_SHIFT) |
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(rq->tag != -1 ?
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rq->tag : (rq->internal_tag | BLK_QC_T_INTERNAL));
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}
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/*
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* Check if any of the ctx, dispatch list or elevator
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* have pending work in this hardware queue.
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*/
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static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
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{
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return !list_empty_careful(&hctx->dispatch) ||
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sbitmap_any_bit_set(&hctx->ctx_map) ||
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blk_mq_sched_has_work(hctx);
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}
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/*
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* Mark this ctx as having pending work in this hardware queue
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*/
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static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
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struct blk_mq_ctx *ctx)
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{
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const int bit = ctx->index_hw[hctx->type];
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if (!sbitmap_test_bit(&hctx->ctx_map, bit))
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sbitmap_set_bit(&hctx->ctx_map, bit);
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}
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static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
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struct blk_mq_ctx *ctx)
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{
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const int bit = ctx->index_hw[hctx->type];
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sbitmap_clear_bit(&hctx->ctx_map, bit);
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}
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struct mq_inflight {
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struct block_device *part;
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unsigned int inflight[2];
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};
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static bool blk_mq_check_inflight(struct request *rq, void *priv,
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bool reserved)
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{
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struct mq_inflight *mi = priv;
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if ((!mi->part->bd_partno || rq->part == mi->part) &&
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blk_mq_rq_state(rq) == MQ_RQ_IN_FLIGHT)
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mi->inflight[rq_data_dir(rq)]++;
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return true;
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}
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unsigned int blk_mq_in_flight(struct request_queue *q,
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struct block_device *part)
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{
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struct mq_inflight mi = { .part = part };
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blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
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return mi.inflight[0] + mi.inflight[1];
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}
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void blk_mq_in_flight_rw(struct request_queue *q, struct block_device *part,
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unsigned int inflight[2])
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{
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struct mq_inflight mi = { .part = part };
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blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
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inflight[0] = mi.inflight[0];
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inflight[1] = mi.inflight[1];
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}
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void blk_freeze_queue_start(struct request_queue *q)
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{
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mutex_lock(&q->mq_freeze_lock);
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if (++q->mq_freeze_depth == 1) {
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percpu_ref_kill(&q->q_usage_counter);
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mutex_unlock(&q->mq_freeze_lock);
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if (queue_is_mq(q))
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blk_mq_run_hw_queues(q, false);
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} else {
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mutex_unlock(&q->mq_freeze_lock);
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}
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}
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EXPORT_SYMBOL_GPL(blk_freeze_queue_start);
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void blk_mq_freeze_queue_wait(struct request_queue *q)
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{
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wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
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}
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EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait);
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int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
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unsigned long timeout)
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{
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return wait_event_timeout(q->mq_freeze_wq,
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percpu_ref_is_zero(&q->q_usage_counter),
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timeout);
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}
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EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_wait_timeout);
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/*
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* Guarantee no request is in use, so we can change any data structure of
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* the queue afterward.
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*/
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void blk_freeze_queue(struct request_queue *q)
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{
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/*
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* In the !blk_mq case we are only calling this to kill the
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* q_usage_counter, otherwise this increases the freeze depth
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* and waits for it to return to zero. For this reason there is
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* no blk_unfreeze_queue(), and blk_freeze_queue() is not
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* exported to drivers as the only user for unfreeze is blk_mq.
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*/
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blk_freeze_queue_start(q);
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blk_mq_freeze_queue_wait(q);
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}
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void blk_mq_freeze_queue(struct request_queue *q)
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{
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/*
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* ...just an alias to keep freeze and unfreeze actions balanced
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* in the blk_mq_* namespace
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*/
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blk_freeze_queue(q);
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}
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EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
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void __blk_mq_unfreeze_queue(struct request_queue *q, bool force_atomic)
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{
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mutex_lock(&q->mq_freeze_lock);
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if (force_atomic)
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q->q_usage_counter.data->force_atomic = true;
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q->mq_freeze_depth--;
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WARN_ON_ONCE(q->mq_freeze_depth < 0);
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if (!q->mq_freeze_depth) {
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percpu_ref_resurrect(&q->q_usage_counter);
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wake_up_all(&q->mq_freeze_wq);
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}
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mutex_unlock(&q->mq_freeze_lock);
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}
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void blk_mq_unfreeze_queue(struct request_queue *q)
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{
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__blk_mq_unfreeze_queue(q, false);
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}
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EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
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/*
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* FIXME: replace the scsi_internal_device_*block_nowait() calls in the
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* mpt3sas driver such that this function can be removed.
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*/
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void blk_mq_quiesce_queue_nowait(struct request_queue *q)
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{
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unsigned long flags;
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spin_lock_irqsave(&q->queue_lock, flags);
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if (!q->quiesce_depth++)
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blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q);
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spin_unlock_irqrestore(&q->queue_lock, flags);
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}
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EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue_nowait);
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/**
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* blk_mq_wait_quiesce_done() - wait until in-progress quiesce is done
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* @q: request queue.
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*
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* Note: it is driver's responsibility for making sure that quiesce has
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* been started.
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*/
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void blk_mq_wait_quiesce_done(struct request_queue *q)
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{
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if (blk_queue_has_srcu(q))
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synchronize_srcu(q->srcu);
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else
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synchronize_rcu();
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}
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EXPORT_SYMBOL_GPL(blk_mq_wait_quiesce_done);
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/**
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* blk_mq_quiesce_queue() - wait until all ongoing dispatches have finished
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* @q: request queue.
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*
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* Note: this function does not prevent that the struct request end_io()
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* callback function is invoked. Once this function is returned, we make
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* sure no dispatch can happen until the queue is unquiesced via
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* blk_mq_unquiesce_queue().
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*/
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void blk_mq_quiesce_queue(struct request_queue *q)
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{
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blk_mq_quiesce_queue_nowait(q);
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blk_mq_wait_quiesce_done(q);
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}
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EXPORT_SYMBOL_GPL(blk_mq_quiesce_queue);
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/*
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* blk_mq_unquiesce_queue() - counterpart of blk_mq_quiesce_queue()
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* @q: request queue.
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*
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* This function recovers queue into the state before quiescing
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* which is done by blk_mq_quiesce_queue.
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*/
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void blk_mq_unquiesce_queue(struct request_queue *q)
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{
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unsigned long flags;
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bool run_queue = false;
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spin_lock_irqsave(&q->queue_lock, flags);
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if (WARN_ON_ONCE(q->quiesce_depth <= 0)) {
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;
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} else if (!--q->quiesce_depth) {
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blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
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run_queue = true;
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}
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spin_unlock_irqrestore(&q->queue_lock, flags);
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/* dispatch requests which are inserted during quiescing */
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if (run_queue)
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blk_mq_run_hw_queues(q, true);
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}
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EXPORT_SYMBOL_GPL(blk_mq_unquiesce_queue);
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void blk_mq_wake_waiters(struct request_queue *q)
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{
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struct blk_mq_hw_ctx *hctx;
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unsigned int i;
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queue_for_each_hw_ctx(q, hctx, i)
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if (blk_mq_hw_queue_mapped(hctx))
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blk_mq_tag_wakeup_all(hctx->tags, true);
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}
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void blk_rq_init(struct request_queue *q, struct request *rq)
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{
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memset(rq, 0, sizeof(*rq));
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INIT_LIST_HEAD(&rq->queuelist);
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rq->q = q;
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rq->__sector = (sector_t) -1;
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INIT_HLIST_NODE(&rq->hash);
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RB_CLEAR_NODE(&rq->rb_node);
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rq->tag = BLK_MQ_NO_TAG;
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rq->internal_tag = BLK_MQ_NO_TAG;
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rq->start_time_ns = ktime_get_ns();
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rq->part = NULL;
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blk_crypto_rq_set_defaults(rq);
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}
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EXPORT_SYMBOL(blk_rq_init);
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static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
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struct blk_mq_tags *tags, unsigned int tag, u64 alloc_time_ns)
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{
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struct blk_mq_ctx *ctx = data->ctx;
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struct blk_mq_hw_ctx *hctx = data->hctx;
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struct request_queue *q = data->q;
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struct request *rq = tags->static_rqs[tag];
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rq->q = q;
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rq->mq_ctx = ctx;
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rq->mq_hctx = hctx;
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rq->cmd_flags = data->cmd_flags;
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if (data->flags & BLK_MQ_REQ_PM)
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data->rq_flags |= RQF_PM;
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if (blk_queue_io_stat(q))
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data->rq_flags |= RQF_IO_STAT;
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rq->rq_flags = data->rq_flags;
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if (!(data->rq_flags & RQF_ELV)) {
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rq->tag = tag;
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rq->internal_tag = BLK_MQ_NO_TAG;
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} else {
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rq->tag = BLK_MQ_NO_TAG;
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rq->internal_tag = tag;
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}
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rq->timeout = 0;
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if (blk_mq_need_time_stamp(rq))
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rq->start_time_ns = ktime_get_ns();
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else
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rq->start_time_ns = 0;
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rq->part = NULL;
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#ifdef CONFIG_BLK_RQ_ALLOC_TIME
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rq->alloc_time_ns = alloc_time_ns;
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#endif
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rq->io_start_time_ns = 0;
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rq->stats_sectors = 0;
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rq->nr_phys_segments = 0;
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#if defined(CONFIG_BLK_DEV_INTEGRITY)
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rq->nr_integrity_segments = 0;
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#endif
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rq->end_io = NULL;
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rq->end_io_data = NULL;
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blk_crypto_rq_set_defaults(rq);
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INIT_LIST_HEAD(&rq->queuelist);
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/* tag was already set */
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WRITE_ONCE(rq->deadline, 0);
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req_ref_set(rq, 1);
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if (rq->rq_flags & RQF_ELV) {
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struct elevator_queue *e = data->q->elevator;
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INIT_HLIST_NODE(&rq->hash);
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RB_CLEAR_NODE(&rq->rb_node);
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if (!op_is_flush(data->cmd_flags) &&
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e->type->ops.prepare_request) {
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e->type->ops.prepare_request(rq);
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rq->rq_flags |= RQF_ELVPRIV;
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}
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}
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return rq;
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}
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static inline struct request *
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__blk_mq_alloc_requests_batch(struct blk_mq_alloc_data *data,
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u64 alloc_time_ns)
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{
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unsigned int tag, tag_offset;
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struct blk_mq_tags *tags;
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struct request *rq;
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unsigned long tag_mask;
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int i, nr = 0;
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tag_mask = blk_mq_get_tags(data, data->nr_tags, &tag_offset);
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if (unlikely(!tag_mask))
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return NULL;
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tags = blk_mq_tags_from_data(data);
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for (i = 0; tag_mask; i++) {
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if (!(tag_mask & (1UL << i)))
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continue;
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tag = tag_offset + i;
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prefetch(tags->static_rqs[tag]);
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tag_mask &= ~(1UL << i);
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rq = blk_mq_rq_ctx_init(data, tags, tag, alloc_time_ns);
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rq_list_add(data->cached_rq, rq);
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nr++;
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}
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/* caller already holds a reference, add for remainder */
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percpu_ref_get_many(&data->q->q_usage_counter, nr - 1);
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data->nr_tags -= nr;
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return rq_list_pop(data->cached_rq);
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}
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static struct request *__blk_mq_alloc_requests(struct blk_mq_alloc_data *data)
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{
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struct request_queue *q = data->q;
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u64 alloc_time_ns = 0;
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struct request *rq;
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unsigned int tag;
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/* alloc_time includes depth and tag waits */
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if (blk_queue_rq_alloc_time(q))
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alloc_time_ns = ktime_get_ns();
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if (data->cmd_flags & REQ_NOWAIT)
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data->flags |= BLK_MQ_REQ_NOWAIT;
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if (q->elevator) {
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struct elevator_queue *e = q->elevator;
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data->rq_flags |= RQF_ELV;
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/*
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* Flush/passthrough requests are special and go directly to the
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* dispatch list. Don't include reserved tags in the
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* limiting, as it isn't useful.
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*/
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if (!op_is_flush(data->cmd_flags) &&
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!blk_op_is_passthrough(data->cmd_flags) &&
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e->type->ops.limit_depth &&
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!(data->flags & BLK_MQ_REQ_RESERVED))
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e->type->ops.limit_depth(data->cmd_flags, data);
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}
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retry:
|
|
data->ctx = blk_mq_get_ctx(q);
|
|
data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);
|
|
if (!(data->rq_flags & RQF_ELV))
|
|
blk_mq_tag_busy(data->hctx);
|
|
|
|
/*
|
|
* Try batched alloc if we want more than 1 tag.
|
|
*/
|
|
if (data->nr_tags > 1) {
|
|
rq = __blk_mq_alloc_requests_batch(data, alloc_time_ns);
|
|
if (rq)
|
|
return rq;
|
|
data->nr_tags = 1;
|
|
}
|
|
|
|
/*
|
|
* Waiting allocations only fail because of an inactive hctx. In that
|
|
* case just retry the hctx assignment and tag allocation as CPU hotplug
|
|
* should have migrated us to an online CPU by now.
|
|
*/
|
|
tag = blk_mq_get_tag(data);
|
|
if (tag == BLK_MQ_NO_TAG) {
|
|
if (data->flags & BLK_MQ_REQ_NOWAIT)
|
|
return NULL;
|
|
/*
|
|
* Give up the CPU and sleep for a random short time to
|
|
* ensure that thread using a realtime scheduling class
|
|
* are migrated off the CPU, and thus off the hctx that
|
|
* is going away.
|
|
*/
|
|
msleep(3);
|
|
goto retry;
|
|
}
|
|
|
|
return blk_mq_rq_ctx_init(data, blk_mq_tags_from_data(data), tag,
|
|
alloc_time_ns);
|
|
}
|
|
|
|
struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
|
|
blk_mq_req_flags_t flags)
|
|
{
|
|
struct blk_mq_alloc_data data = {
|
|
.q = q,
|
|
.flags = flags,
|
|
.cmd_flags = op,
|
|
.nr_tags = 1,
|
|
};
|
|
struct request *rq;
|
|
int ret;
|
|
|
|
ret = blk_queue_enter(q, flags);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
|
|
rq = __blk_mq_alloc_requests(&data);
|
|
if (!rq)
|
|
goto out_queue_exit;
|
|
rq->__data_len = 0;
|
|
rq->__sector = (sector_t) -1;
|
|
rq->bio = rq->biotail = NULL;
|
|
return rq;
|
|
out_queue_exit:
|
|
blk_queue_exit(q);
|
|
return ERR_PTR(-EWOULDBLOCK);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_alloc_request);
|
|
|
|
struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
|
|
unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx)
|
|
{
|
|
struct blk_mq_alloc_data data = {
|
|
.q = q,
|
|
.flags = flags,
|
|
.cmd_flags = op,
|
|
.nr_tags = 1,
|
|
};
|
|
u64 alloc_time_ns = 0;
|
|
unsigned int cpu;
|
|
unsigned int tag;
|
|
int ret;
|
|
|
|
/* alloc_time includes depth and tag waits */
|
|
if (blk_queue_rq_alloc_time(q))
|
|
alloc_time_ns = ktime_get_ns();
|
|
|
|
/*
|
|
* If the tag allocator sleeps we could get an allocation for a
|
|
* different hardware context. No need to complicate the low level
|
|
* allocator for this for the rare use case of a command tied to
|
|
* a specific queue.
|
|
*/
|
|
if (WARN_ON_ONCE(!(flags & (BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED))))
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
if (hctx_idx >= q->nr_hw_queues)
|
|
return ERR_PTR(-EIO);
|
|
|
|
ret = blk_queue_enter(q, flags);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
|
|
/*
|
|
* Check if the hardware context is actually mapped to anything.
|
|
* If not tell the caller that it should skip this queue.
|
|
*/
|
|
ret = -EXDEV;
|
|
data.hctx = q->queue_hw_ctx[hctx_idx];
|
|
if (!blk_mq_hw_queue_mapped(data.hctx))
|
|
goto out_queue_exit;
|
|
cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
|
|
data.ctx = __blk_mq_get_ctx(q, cpu);
|
|
|
|
if (!q->elevator)
|
|
blk_mq_tag_busy(data.hctx);
|
|
else
|
|
data.rq_flags |= RQF_ELV;
|
|
|
|
ret = -EWOULDBLOCK;
|
|
tag = blk_mq_get_tag(&data);
|
|
if (tag == BLK_MQ_NO_TAG)
|
|
goto out_queue_exit;
|
|
return blk_mq_rq_ctx_init(&data, blk_mq_tags_from_data(&data), tag,
|
|
alloc_time_ns);
|
|
|
|
out_queue_exit:
|
|
blk_queue_exit(q);
|
|
return ERR_PTR(ret);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_alloc_request_hctx);
|
|
|
|
static void __blk_mq_free_request(struct request *rq)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx;
|
|
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
|
|
const int sched_tag = rq->internal_tag;
|
|
|
|
blk_crypto_free_request(rq);
|
|
blk_pm_mark_last_busy(rq);
|
|
rq->mq_hctx = NULL;
|
|
if (rq->tag != BLK_MQ_NO_TAG)
|
|
blk_mq_put_tag(hctx->tags, ctx, rq->tag);
|
|
if (sched_tag != BLK_MQ_NO_TAG)
|
|
blk_mq_put_tag(hctx->sched_tags, ctx, sched_tag);
|
|
blk_mq_sched_restart(hctx);
|
|
blk_queue_exit(q);
|
|
}
|
|
|
|
void blk_mq_free_request(struct request *rq)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
|
|
|
|
if ((rq->rq_flags & RQF_ELVPRIV) &&
|
|
q->elevator->type->ops.finish_request)
|
|
q->elevator->type->ops.finish_request(rq);
|
|
|
|
if (rq->rq_flags & RQF_MQ_INFLIGHT)
|
|
__blk_mq_dec_active_requests(hctx);
|
|
|
|
if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq)))
|
|
laptop_io_completion(q->disk->bdi);
|
|
|
|
rq_qos_done(q, rq);
|
|
|
|
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
|
|
if (req_ref_put_and_test(rq))
|
|
__blk_mq_free_request(rq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_free_request);
|
|
|
|
void blk_mq_free_plug_rqs(struct blk_plug *plug)
|
|
{
|
|
struct request *rq;
|
|
|
|
while ((rq = rq_list_pop(&plug->cached_rq)) != NULL)
|
|
blk_mq_free_request(rq);
|
|
}
|
|
|
|
void blk_dump_rq_flags(struct request *rq, char *msg)
|
|
{
|
|
printk(KERN_INFO "%s: dev %s: flags=%llx\n", msg,
|
|
rq->q->disk ? rq->q->disk->disk_name : "?",
|
|
(unsigned long long) rq->cmd_flags);
|
|
|
|
printk(KERN_INFO " sector %llu, nr/cnr %u/%u\n",
|
|
(unsigned long long)blk_rq_pos(rq),
|
|
blk_rq_sectors(rq), blk_rq_cur_sectors(rq));
|
|
printk(KERN_INFO " bio %p, biotail %p, len %u\n",
|
|
rq->bio, rq->biotail, blk_rq_bytes(rq));
|
|
}
|
|
EXPORT_SYMBOL(blk_dump_rq_flags);
|
|
|
|
static void req_bio_endio(struct request *rq, struct bio *bio,
|
|
unsigned int nbytes, blk_status_t error)
|
|
{
|
|
if (unlikely(error)) {
|
|
bio->bi_status = error;
|
|
} else if (req_op(rq) == REQ_OP_ZONE_APPEND) {
|
|
/*
|
|
* Partial zone append completions cannot be supported as the
|
|
* BIO fragments may end up not being written sequentially.
|
|
*/
|
|
if (bio->bi_iter.bi_size != nbytes)
|
|
bio->bi_status = BLK_STS_IOERR;
|
|
else
|
|
bio->bi_iter.bi_sector = rq->__sector;
|
|
}
|
|
|
|
bio_advance(bio, nbytes);
|
|
|
|
if (unlikely(rq->rq_flags & RQF_QUIET))
|
|
bio_set_flag(bio, BIO_QUIET);
|
|
/* don't actually finish bio if it's part of flush sequence */
|
|
if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ))
|
|
bio_endio(bio);
|
|
}
|
|
|
|
static void blk_account_io_completion(struct request *req, unsigned int bytes)
|
|
{
|
|
if (req->part && blk_do_io_stat(req)) {
|
|
const int sgrp = op_stat_group(req_op(req));
|
|
|
|
part_stat_lock();
|
|
part_stat_add(req->part, sectors[sgrp], bytes >> 9);
|
|
part_stat_unlock();
|
|
}
|
|
}
|
|
|
|
static void blk_print_req_error(struct request *req, blk_status_t status)
|
|
{
|
|
printk_ratelimited(KERN_ERR
|
|
"%s error, dev %s, sector %llu op 0x%x:(%s) flags 0x%x "
|
|
"phys_seg %u prio class %u\n",
|
|
blk_status_to_str(status),
|
|
req->q->disk ? req->q->disk->disk_name : "?",
|
|
blk_rq_pos(req), req_op(req), blk_op_str(req_op(req)),
|
|
req->cmd_flags & ~REQ_OP_MASK,
|
|
req->nr_phys_segments,
|
|
IOPRIO_PRIO_CLASS(req->ioprio));
|
|
}
|
|
|
|
/*
|
|
* Fully end IO on a request. Does not support partial completions, or
|
|
* errors.
|
|
*/
|
|
static void blk_complete_request(struct request *req)
|
|
{
|
|
const bool is_flush = (req->rq_flags & RQF_FLUSH_SEQ) != 0;
|
|
int total_bytes = blk_rq_bytes(req);
|
|
struct bio *bio = req->bio;
|
|
|
|
trace_block_rq_complete(req, BLK_STS_OK, total_bytes);
|
|
|
|
if (!bio)
|
|
return;
|
|
|
|
#ifdef CONFIG_BLK_DEV_INTEGRITY
|
|
if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ)
|
|
req->q->integrity.profile->complete_fn(req, total_bytes);
|
|
#endif
|
|
|
|
blk_account_io_completion(req, total_bytes);
|
|
|
|
do {
|
|
struct bio *next = bio->bi_next;
|
|
|
|
/* Completion has already been traced */
|
|
bio_clear_flag(bio, BIO_TRACE_COMPLETION);
|
|
if (!is_flush)
|
|
bio_endio(bio);
|
|
bio = next;
|
|
} while (bio);
|
|
|
|
/*
|
|
* Reset counters so that the request stacking driver
|
|
* can find how many bytes remain in the request
|
|
* later.
|
|
*/
|
|
req->bio = NULL;
|
|
req->__data_len = 0;
|
|
}
|
|
|
|
/**
|
|
* blk_update_request - Complete multiple bytes without completing the request
|
|
* @req: the request being processed
|
|
* @error: block status code
|
|
* @nr_bytes: number of bytes to complete for @req
|
|
*
|
|
* Description:
|
|
* Ends I/O on a number of bytes attached to @req, but doesn't complete
|
|
* the request structure even if @req doesn't have leftover.
|
|
* If @req has leftover, sets it up for the next range of segments.
|
|
*
|
|
* Passing the result of blk_rq_bytes() as @nr_bytes guarantees
|
|
* %false return from this function.
|
|
*
|
|
* Note:
|
|
* The RQF_SPECIAL_PAYLOAD flag is ignored on purpose in this function
|
|
* except in the consistency check at the end of this function.
|
|
*
|
|
* Return:
|
|
* %false - this request doesn't have any more data
|
|
* %true - this request has more data
|
|
**/
|
|
bool blk_update_request(struct request *req, blk_status_t error,
|
|
unsigned int nr_bytes)
|
|
{
|
|
int total_bytes;
|
|
|
|
trace_block_rq_complete(req, error, nr_bytes);
|
|
|
|
if (!req->bio)
|
|
return false;
|
|
|
|
#ifdef CONFIG_BLK_DEV_INTEGRITY
|
|
if (blk_integrity_rq(req) && req_op(req) == REQ_OP_READ &&
|
|
error == BLK_STS_OK)
|
|
req->q->integrity.profile->complete_fn(req, nr_bytes);
|
|
#endif
|
|
|
|
if (unlikely(error && !blk_rq_is_passthrough(req) &&
|
|
!(req->rq_flags & RQF_QUIET)))
|
|
blk_print_req_error(req, error);
|
|
|
|
blk_account_io_completion(req, nr_bytes);
|
|
|
|
total_bytes = 0;
|
|
while (req->bio) {
|
|
struct bio *bio = req->bio;
|
|
unsigned bio_bytes = min(bio->bi_iter.bi_size, nr_bytes);
|
|
|
|
if (bio_bytes == bio->bi_iter.bi_size)
|
|
req->bio = bio->bi_next;
|
|
|
|
/* Completion has already been traced */
|
|
bio_clear_flag(bio, BIO_TRACE_COMPLETION);
|
|
req_bio_endio(req, bio, bio_bytes, error);
|
|
|
|
total_bytes += bio_bytes;
|
|
nr_bytes -= bio_bytes;
|
|
|
|
if (!nr_bytes)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* completely done
|
|
*/
|
|
if (!req->bio) {
|
|
/*
|
|
* Reset counters so that the request stacking driver
|
|
* can find how many bytes remain in the request
|
|
* later.
|
|
*/
|
|
req->__data_len = 0;
|
|
return false;
|
|
}
|
|
|
|
req->__data_len -= total_bytes;
|
|
|
|
/* update sector only for requests with clear definition of sector */
|
|
if (!blk_rq_is_passthrough(req))
|
|
req->__sector += total_bytes >> 9;
|
|
|
|
/* mixed attributes always follow the first bio */
|
|
if (req->rq_flags & RQF_MIXED_MERGE) {
|
|
req->cmd_flags &= ~REQ_FAILFAST_MASK;
|
|
req->cmd_flags |= req->bio->bi_opf & REQ_FAILFAST_MASK;
|
|
}
|
|
|
|
if (!(req->rq_flags & RQF_SPECIAL_PAYLOAD)) {
|
|
/*
|
|
* If total number of sectors is less than the first segment
|
|
* size, something has gone terribly wrong.
|
|
*/
|
|
if (blk_rq_bytes(req) < blk_rq_cur_bytes(req)) {
|
|
blk_dump_rq_flags(req, "request botched");
|
|
req->__data_len = blk_rq_cur_bytes(req);
|
|
}
|
|
|
|
/* recalculate the number of segments */
|
|
req->nr_phys_segments = blk_recalc_rq_segments(req);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_update_request);
|
|
|
|
static void __blk_account_io_done(struct request *req, u64 now)
|
|
{
|
|
const int sgrp = op_stat_group(req_op(req));
|
|
|
|
part_stat_lock();
|
|
update_io_ticks(req->part, jiffies, true);
|
|
part_stat_inc(req->part, ios[sgrp]);
|
|
part_stat_add(req->part, nsecs[sgrp], now - req->start_time_ns);
|
|
part_stat_unlock();
|
|
}
|
|
|
|
static inline void blk_account_io_done(struct request *req, u64 now)
|
|
{
|
|
/*
|
|
* Account IO completion. flush_rq isn't accounted as a
|
|
* normal IO on queueing nor completion. Accounting the
|
|
* containing request is enough.
|
|
*/
|
|
if (blk_do_io_stat(req) && req->part &&
|
|
!(req->rq_flags & RQF_FLUSH_SEQ))
|
|
__blk_account_io_done(req, now);
|
|
}
|
|
|
|
static void __blk_account_io_start(struct request *rq)
|
|
{
|
|
/* passthrough requests can hold bios that do not have ->bi_bdev set */
|
|
if (rq->bio && rq->bio->bi_bdev)
|
|
rq->part = rq->bio->bi_bdev;
|
|
else if (rq->q->disk)
|
|
rq->part = rq->q->disk->part0;
|
|
|
|
part_stat_lock();
|
|
update_io_ticks(rq->part, jiffies, false);
|
|
part_stat_unlock();
|
|
}
|
|
|
|
static inline void blk_account_io_start(struct request *req)
|
|
{
|
|
if (blk_do_io_stat(req))
|
|
__blk_account_io_start(req);
|
|
}
|
|
|
|
static inline void __blk_mq_end_request_acct(struct request *rq, u64 now)
|
|
{
|
|
if (rq->rq_flags & RQF_STATS) {
|
|
blk_mq_poll_stats_start(rq->q);
|
|
blk_stat_add(rq, now);
|
|
}
|
|
|
|
blk_mq_sched_completed_request(rq, now);
|
|
blk_account_io_done(rq, now);
|
|
}
|
|
|
|
inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
|
|
{
|
|
if (blk_mq_need_time_stamp(rq))
|
|
__blk_mq_end_request_acct(rq, ktime_get_ns());
|
|
|
|
if (rq->end_io) {
|
|
rq_qos_done(rq->q, rq);
|
|
rq->end_io(rq, error);
|
|
} else {
|
|
blk_mq_free_request(rq);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(__blk_mq_end_request);
|
|
|
|
void blk_mq_end_request(struct request *rq, blk_status_t error)
|
|
{
|
|
if (blk_update_request(rq, error, blk_rq_bytes(rq)))
|
|
BUG();
|
|
__blk_mq_end_request(rq, error);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_end_request);
|
|
|
|
#define TAG_COMP_BATCH 32
|
|
|
|
static inline void blk_mq_flush_tag_batch(struct blk_mq_hw_ctx *hctx,
|
|
int *tag_array, int nr_tags)
|
|
{
|
|
struct request_queue *q = hctx->queue;
|
|
|
|
/*
|
|
* All requests should have been marked as RQF_MQ_INFLIGHT, so
|
|
* update hctx->nr_active in batch
|
|
*/
|
|
if (hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
|
|
__blk_mq_sub_active_requests(hctx, nr_tags);
|
|
|
|
blk_mq_put_tags(hctx->tags, tag_array, nr_tags);
|
|
percpu_ref_put_many(&q->q_usage_counter, nr_tags);
|
|
}
|
|
|
|
void blk_mq_end_request_batch(struct io_comp_batch *iob)
|
|
{
|
|
int tags[TAG_COMP_BATCH], nr_tags = 0;
|
|
struct blk_mq_hw_ctx *cur_hctx = NULL;
|
|
struct request *rq;
|
|
u64 now = 0;
|
|
|
|
if (iob->need_ts)
|
|
now = ktime_get_ns();
|
|
|
|
while ((rq = rq_list_pop(&iob->req_list)) != NULL) {
|
|
prefetch(rq->bio);
|
|
prefetch(rq->rq_next);
|
|
|
|
blk_complete_request(rq);
|
|
if (iob->need_ts)
|
|
__blk_mq_end_request_acct(rq, now);
|
|
|
|
rq_qos_done(rq->q, rq);
|
|
|
|
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
|
|
if (!req_ref_put_and_test(rq))
|
|
continue;
|
|
|
|
blk_crypto_free_request(rq);
|
|
blk_pm_mark_last_busy(rq);
|
|
|
|
if (nr_tags == TAG_COMP_BATCH || cur_hctx != rq->mq_hctx) {
|
|
if (cur_hctx)
|
|
blk_mq_flush_tag_batch(cur_hctx, tags, nr_tags);
|
|
nr_tags = 0;
|
|
cur_hctx = rq->mq_hctx;
|
|
}
|
|
tags[nr_tags++] = rq->tag;
|
|
}
|
|
|
|
if (nr_tags)
|
|
blk_mq_flush_tag_batch(cur_hctx, tags, nr_tags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_end_request_batch);
|
|
|
|
static void blk_complete_reqs(struct llist_head *list)
|
|
{
|
|
struct llist_node *entry = llist_reverse_order(llist_del_all(list));
|
|
struct request *rq, *next;
|
|
|
|
llist_for_each_entry_safe(rq, next, entry, ipi_list)
|
|
rq->q->mq_ops->complete(rq);
|
|
}
|
|
|
|
static __latent_entropy void blk_done_softirq(struct softirq_action *h)
|
|
{
|
|
blk_complete_reqs(this_cpu_ptr(&blk_cpu_done));
|
|
}
|
|
|
|
static int blk_softirq_cpu_dead(unsigned int cpu)
|
|
{
|
|
blk_complete_reqs(&per_cpu(blk_cpu_done, cpu));
|
|
return 0;
|
|
}
|
|
|
|
static void __blk_mq_complete_request_remote(void *data)
|
|
{
|
|
__raise_softirq_irqoff(BLOCK_SOFTIRQ);
|
|
}
|
|
|
|
static inline bool blk_mq_complete_need_ipi(struct request *rq)
|
|
{
|
|
int cpu = raw_smp_processor_id();
|
|
|
|
if (!IS_ENABLED(CONFIG_SMP) ||
|
|
!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags))
|
|
return false;
|
|
/*
|
|
* With force threaded interrupts enabled, raising softirq from an SMP
|
|
* function call will always result in waking the ksoftirqd thread.
|
|
* This is probably worse than completing the request on a different
|
|
* cache domain.
|
|
*/
|
|
if (force_irqthreads())
|
|
return false;
|
|
|
|
/* same CPU or cache domain? Complete locally */
|
|
if (cpu == rq->mq_ctx->cpu ||
|
|
(!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags) &&
|
|
cpus_share_cache(cpu, rq->mq_ctx->cpu)))
|
|
return false;
|
|
|
|
/* don't try to IPI to an offline CPU */
|
|
return cpu_online(rq->mq_ctx->cpu);
|
|
}
|
|
|
|
static void blk_mq_complete_send_ipi(struct request *rq)
|
|
{
|
|
struct llist_head *list;
|
|
unsigned int cpu;
|
|
|
|
cpu = rq->mq_ctx->cpu;
|
|
list = &per_cpu(blk_cpu_done, cpu);
|
|
if (llist_add(&rq->ipi_list, list)) {
|
|
INIT_CSD(&rq->csd, __blk_mq_complete_request_remote, rq);
|
|
smp_call_function_single_async(cpu, &rq->csd);
|
|
}
|
|
}
|
|
|
|
static void blk_mq_raise_softirq(struct request *rq)
|
|
{
|
|
struct llist_head *list;
|
|
|
|
preempt_disable();
|
|
list = this_cpu_ptr(&blk_cpu_done);
|
|
if (llist_add(&rq->ipi_list, list))
|
|
raise_softirq(BLOCK_SOFTIRQ);
|
|
preempt_enable();
|
|
}
|
|
|
|
bool blk_mq_complete_request_remote(struct request *rq)
|
|
{
|
|
WRITE_ONCE(rq->state, MQ_RQ_COMPLETE);
|
|
|
|
/*
|
|
* For a polled request, always complete locallly, it's pointless
|
|
* to redirect the completion.
|
|
*/
|
|
if (rq->cmd_flags & REQ_POLLED)
|
|
return false;
|
|
|
|
if (blk_mq_complete_need_ipi(rq)) {
|
|
blk_mq_complete_send_ipi(rq);
|
|
return true;
|
|
}
|
|
|
|
if (rq->q->nr_hw_queues == 1) {
|
|
blk_mq_raise_softirq(rq);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_complete_request_remote);
|
|
|
|
/**
|
|
* blk_mq_complete_request - end I/O on a request
|
|
* @rq: the request being processed
|
|
*
|
|
* Description:
|
|
* Complete a request by scheduling the ->complete_rq operation.
|
|
**/
|
|
void blk_mq_complete_request(struct request *rq)
|
|
{
|
|
if (!blk_mq_complete_request_remote(rq))
|
|
rq->q->mq_ops->complete(rq);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_complete_request);
|
|
|
|
/**
|
|
* blk_mq_start_request - Start processing a request
|
|
* @rq: Pointer to request to be started
|
|
*
|
|
* Function used by device drivers to notify the block layer that a request
|
|
* is going to be processed now, so blk layer can do proper initializations
|
|
* such as starting the timeout timer.
|
|
*/
|
|
void blk_mq_start_request(struct request *rq)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
|
|
trace_block_rq_issue(rq);
|
|
|
|
if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
|
|
u64 start_time;
|
|
#ifdef CONFIG_BLK_CGROUP
|
|
if (rq->bio)
|
|
start_time = bio_issue_time(&rq->bio->bi_issue);
|
|
else
|
|
#endif
|
|
start_time = ktime_get_ns();
|
|
rq->io_start_time_ns = start_time;
|
|
rq->stats_sectors = blk_rq_sectors(rq);
|
|
rq->rq_flags |= RQF_STATS;
|
|
rq_qos_issue(q, rq);
|
|
}
|
|
|
|
WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE);
|
|
|
|
blk_add_timer(rq);
|
|
WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT);
|
|
|
|
#ifdef CONFIG_BLK_DEV_INTEGRITY
|
|
if (blk_integrity_rq(rq) && req_op(rq) == REQ_OP_WRITE)
|
|
q->integrity.profile->prepare_fn(rq);
|
|
#endif
|
|
if (rq->bio && rq->bio->bi_opf & REQ_POLLED)
|
|
WRITE_ONCE(rq->bio->bi_cookie, blk_rq_to_qc(rq));
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_start_request);
|
|
|
|
/**
|
|
* blk_end_sync_rq - executes a completion event on a request
|
|
* @rq: request to complete
|
|
* @error: end I/O status of the request
|
|
*/
|
|
static void blk_end_sync_rq(struct request *rq, blk_status_t error)
|
|
{
|
|
struct completion *waiting = rq->end_io_data;
|
|
|
|
rq->end_io_data = (void *)(uintptr_t)error;
|
|
|
|
/*
|
|
* complete last, if this is a stack request the process (and thus
|
|
* the rq pointer) could be invalid right after this complete()
|
|
*/
|
|
complete(waiting);
|
|
}
|
|
|
|
/**
|
|
* blk_execute_rq_nowait - insert a request to I/O scheduler for execution
|
|
* @rq: request to insert
|
|
* @at_head: insert request at head or tail of queue
|
|
* @done: I/O completion handler
|
|
*
|
|
* Description:
|
|
* Insert a fully prepared request at the back of the I/O scheduler queue
|
|
* for execution. Don't wait for completion.
|
|
*
|
|
* Note:
|
|
* This function will invoke @done directly if the queue is dead.
|
|
*/
|
|
void blk_execute_rq_nowait(struct request *rq, bool at_head, rq_end_io_fn *done)
|
|
{
|
|
WARN_ON(irqs_disabled());
|
|
WARN_ON(!blk_rq_is_passthrough(rq));
|
|
|
|
rq->end_io = done;
|
|
|
|
blk_account_io_start(rq);
|
|
|
|
/*
|
|
* don't check dying flag for MQ because the request won't
|
|
* be reused after dying flag is set
|
|
*/
|
|
blk_mq_sched_insert_request(rq, at_head, true, false);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
|
|
|
|
static bool blk_rq_is_poll(struct request *rq)
|
|
{
|
|
if (!rq->mq_hctx)
|
|
return false;
|
|
if (rq->mq_hctx->type != HCTX_TYPE_POLL)
|
|
return false;
|
|
if (WARN_ON_ONCE(!rq->bio))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static void blk_rq_poll_completion(struct request *rq, struct completion *wait)
|
|
{
|
|
do {
|
|
bio_poll(rq->bio, NULL, 0);
|
|
cond_resched();
|
|
} while (!completion_done(wait));
|
|
}
|
|
|
|
/**
|
|
* blk_execute_rq - insert a request into queue for execution
|
|
* @rq: request to insert
|
|
* @at_head: insert request at head or tail of queue
|
|
*
|
|
* Description:
|
|
* Insert a fully prepared request at the back of the I/O scheduler queue
|
|
* for execution and wait for completion.
|
|
* Return: The blk_status_t result provided to blk_mq_end_request().
|
|
*/
|
|
blk_status_t blk_execute_rq(struct request *rq, bool at_head)
|
|
{
|
|
DECLARE_COMPLETION_ONSTACK(wait);
|
|
unsigned long hang_check;
|
|
|
|
rq->end_io_data = &wait;
|
|
blk_execute_rq_nowait(rq, at_head, blk_end_sync_rq);
|
|
|
|
/* Prevent hang_check timer from firing at us during very long I/O */
|
|
hang_check = sysctl_hung_task_timeout_secs;
|
|
|
|
if (blk_rq_is_poll(rq))
|
|
blk_rq_poll_completion(rq, &wait);
|
|
else if (hang_check)
|
|
while (!wait_for_completion_io_timeout(&wait,
|
|
hang_check * (HZ/2)))
|
|
;
|
|
else
|
|
wait_for_completion_io(&wait);
|
|
|
|
return (blk_status_t)(uintptr_t)rq->end_io_data;
|
|
}
|
|
EXPORT_SYMBOL(blk_execute_rq);
|
|
|
|
static void __blk_mq_requeue_request(struct request *rq)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
|
|
blk_mq_put_driver_tag(rq);
|
|
|
|
trace_block_rq_requeue(rq);
|
|
rq_qos_requeue(q, rq);
|
|
|
|
if (blk_mq_request_started(rq)) {
|
|
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
|
|
rq->rq_flags &= ~RQF_TIMED_OUT;
|
|
}
|
|
}
|
|
|
|
void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list)
|
|
{
|
|
__blk_mq_requeue_request(rq);
|
|
|
|
/* this request will be re-inserted to io scheduler queue */
|
|
blk_mq_sched_requeue_request(rq);
|
|
|
|
blk_mq_add_to_requeue_list(rq, true, kick_requeue_list);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_requeue_request);
|
|
|
|
static void blk_mq_requeue_work(struct work_struct *work)
|
|
{
|
|
struct request_queue *q =
|
|
container_of(work, struct request_queue, requeue_work.work);
|
|
LIST_HEAD(rq_list);
|
|
struct request *rq, *next;
|
|
|
|
spin_lock_irq(&q->requeue_lock);
|
|
list_splice_init(&q->requeue_list, &rq_list);
|
|
spin_unlock_irq(&q->requeue_lock);
|
|
|
|
list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
|
|
if (!(rq->rq_flags & (RQF_SOFTBARRIER | RQF_DONTPREP)))
|
|
continue;
|
|
|
|
rq->rq_flags &= ~RQF_SOFTBARRIER;
|
|
list_del_init(&rq->queuelist);
|
|
/*
|
|
* If RQF_DONTPREP, rq has contained some driver specific
|
|
* data, so insert it to hctx dispatch list to avoid any
|
|
* merge.
|
|
*/
|
|
if (rq->rq_flags & RQF_DONTPREP)
|
|
blk_mq_request_bypass_insert(rq, false, false);
|
|
else
|
|
blk_mq_sched_insert_request(rq, true, false, false);
|
|
}
|
|
|
|
while (!list_empty(&rq_list)) {
|
|
rq = list_entry(rq_list.next, struct request, queuelist);
|
|
list_del_init(&rq->queuelist);
|
|
blk_mq_sched_insert_request(rq, false, false, false);
|
|
}
|
|
|
|
blk_mq_run_hw_queues(q, false);
|
|
}
|
|
|
|
void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
|
|
bool kick_requeue_list)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* We abuse this flag that is otherwise used by the I/O scheduler to
|
|
* request head insertion from the workqueue.
|
|
*/
|
|
BUG_ON(rq->rq_flags & RQF_SOFTBARRIER);
|
|
|
|
spin_lock_irqsave(&q->requeue_lock, flags);
|
|
if (at_head) {
|
|
rq->rq_flags |= RQF_SOFTBARRIER;
|
|
list_add(&rq->queuelist, &q->requeue_list);
|
|
} else {
|
|
list_add_tail(&rq->queuelist, &q->requeue_list);
|
|
}
|
|
spin_unlock_irqrestore(&q->requeue_lock, flags);
|
|
|
|
if (kick_requeue_list)
|
|
blk_mq_kick_requeue_list(q);
|
|
}
|
|
|
|
void blk_mq_kick_requeue_list(struct request_queue *q)
|
|
{
|
|
kblockd_mod_delayed_work_on(WORK_CPU_UNBOUND, &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_mod_delayed_work_on(WORK_CPU_UNBOUND, &q->requeue_work,
|
|
msecs_to_jiffies(msecs));
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_delay_kick_requeue_list);
|
|
|
|
static bool blk_mq_rq_inflight(struct request *rq, void *priv,
|
|
bool reserved)
|
|
{
|
|
/*
|
|
* If we find a request that isn't idle we know the queue is busy
|
|
* as it's checked in the iter.
|
|
* Return false to stop the iteration.
|
|
*/
|
|
if (blk_mq_request_started(rq)) {
|
|
bool *busy = priv;
|
|
|
|
*busy = true;
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool blk_mq_queue_inflight(struct request_queue *q)
|
|
{
|
|
bool busy = false;
|
|
|
|
blk_mq_queue_tag_busy_iter(q, blk_mq_rq_inflight, &busy);
|
|
return busy;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_queue_inflight);
|
|
|
|
static void blk_mq_rq_timed_out(struct request *req, bool reserved)
|
|
{
|
|
req->rq_flags |= RQF_TIMED_OUT;
|
|
if (req->q->mq_ops->timeout) {
|
|
enum blk_eh_timer_return ret;
|
|
|
|
ret = req->q->mq_ops->timeout(req, reserved);
|
|
if (ret == BLK_EH_DONE)
|
|
return;
|
|
WARN_ON_ONCE(ret != BLK_EH_RESET_TIMER);
|
|
}
|
|
|
|
blk_add_timer(req);
|
|
}
|
|
|
|
static bool blk_mq_req_expired(struct request *rq, unsigned long *next)
|
|
{
|
|
unsigned long deadline;
|
|
|
|
if (blk_mq_rq_state(rq) != MQ_RQ_IN_FLIGHT)
|
|
return false;
|
|
if (rq->rq_flags & RQF_TIMED_OUT)
|
|
return false;
|
|
|
|
deadline = READ_ONCE(rq->deadline);
|
|
if (time_after_eq(jiffies, deadline))
|
|
return true;
|
|
|
|
if (*next == 0)
|
|
*next = deadline;
|
|
else if (time_after(*next, deadline))
|
|
*next = deadline;
|
|
return false;
|
|
}
|
|
|
|
void blk_mq_put_rq_ref(struct request *rq)
|
|
{
|
|
if (is_flush_rq(rq))
|
|
rq->end_io(rq, 0);
|
|
else if (req_ref_put_and_test(rq))
|
|
__blk_mq_free_request(rq);
|
|
}
|
|
|
|
static bool blk_mq_check_expired(struct request *rq, void *priv, bool reserved)
|
|
{
|
|
unsigned long *next = priv;
|
|
|
|
/*
|
|
* blk_mq_queue_tag_busy_iter() has locked the request, so it cannot
|
|
* be reallocated underneath the timeout handler's processing, then
|
|
* the expire check is reliable. If the request is not expired, then
|
|
* it was completed and reallocated as a new request after returning
|
|
* from blk_mq_check_expired().
|
|
*/
|
|
if (blk_mq_req_expired(rq, next))
|
|
blk_mq_rq_timed_out(rq, reserved);
|
|
return true;
|
|
}
|
|
|
|
static void blk_mq_timeout_work(struct work_struct *work)
|
|
{
|
|
struct request_queue *q =
|
|
container_of(work, struct request_queue, timeout_work);
|
|
unsigned long next = 0;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
/* 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_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, &next);
|
|
|
|
if (next != 0) {
|
|
mod_timer(&q->timeout, next);
|
|
} else {
|
|
/*
|
|
* Request timeouts are handled as a forward rolling timer. If
|
|
* we end up here it means that no requests are pending and
|
|
* also that no request has been pending for a while. Mark
|
|
* each hctx as idle.
|
|
*/
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
/* the hctx may be unmapped, so check it here */
|
|
if (blk_mq_hw_queue_mapped(hctx))
|
|
blk_mq_tag_idle(hctx);
|
|
}
|
|
}
|
|
blk_queue_exit(q);
|
|
}
|
|
|
|
struct flush_busy_ctx_data {
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct list_head *list;
|
|
};
|
|
|
|
static bool flush_busy_ctx(struct sbitmap *sb, unsigned int bitnr, void *data)
|
|
{
|
|
struct flush_busy_ctx_data *flush_data = data;
|
|
struct blk_mq_hw_ctx *hctx = flush_data->hctx;
|
|
struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
|
|
enum hctx_type type = hctx->type;
|
|
|
|
spin_lock(&ctx->lock);
|
|
list_splice_tail_init(&ctx->rq_lists[type], flush_data->list);
|
|
sbitmap_clear_bit(sb, bitnr);
|
|
spin_unlock(&ctx->lock);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* Process software queues that have been marked busy, splicing them
|
|
* to the for-dispatch
|
|
*/
|
|
void blk_mq_flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
|
|
{
|
|
struct flush_busy_ctx_data data = {
|
|
.hctx = hctx,
|
|
.list = list,
|
|
};
|
|
|
|
sbitmap_for_each_set(&hctx->ctx_map, flush_busy_ctx, &data);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_flush_busy_ctxs);
|
|
|
|
struct dispatch_rq_data {
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct request *rq;
|
|
};
|
|
|
|
static bool dispatch_rq_from_ctx(struct sbitmap *sb, unsigned int bitnr,
|
|
void *data)
|
|
{
|
|
struct dispatch_rq_data *dispatch_data = data;
|
|
struct blk_mq_hw_ctx *hctx = dispatch_data->hctx;
|
|
struct blk_mq_ctx *ctx = hctx->ctxs[bitnr];
|
|
enum hctx_type type = hctx->type;
|
|
|
|
spin_lock(&ctx->lock);
|
|
if (!list_empty(&ctx->rq_lists[type])) {
|
|
dispatch_data->rq = list_entry_rq(ctx->rq_lists[type].next);
|
|
list_del_init(&dispatch_data->rq->queuelist);
|
|
if (list_empty(&ctx->rq_lists[type]))
|
|
sbitmap_clear_bit(sb, bitnr);
|
|
}
|
|
spin_unlock(&ctx->lock);
|
|
|
|
return !dispatch_data->rq;
|
|
}
|
|
|
|
struct request *blk_mq_dequeue_from_ctx(struct blk_mq_hw_ctx *hctx,
|
|
struct blk_mq_ctx *start)
|
|
{
|
|
unsigned off = start ? start->index_hw[hctx->type] : 0;
|
|
struct dispatch_rq_data data = {
|
|
.hctx = hctx,
|
|
.rq = NULL,
|
|
};
|
|
|
|
__sbitmap_for_each_set(&hctx->ctx_map, off,
|
|
dispatch_rq_from_ctx, &data);
|
|
|
|
return data.rq;
|
|
}
|
|
|
|
static bool __blk_mq_alloc_driver_tag(struct request *rq)
|
|
{
|
|
struct sbitmap_queue *bt = &rq->mq_hctx->tags->bitmap_tags;
|
|
unsigned int tag_offset = rq->mq_hctx->tags->nr_reserved_tags;
|
|
int tag;
|
|
|
|
blk_mq_tag_busy(rq->mq_hctx);
|
|
|
|
if (blk_mq_tag_is_reserved(rq->mq_hctx->sched_tags, rq->internal_tag)) {
|
|
bt = &rq->mq_hctx->tags->breserved_tags;
|
|
tag_offset = 0;
|
|
} else {
|
|
if (!hctx_may_queue(rq->mq_hctx, bt))
|
|
return false;
|
|
}
|
|
|
|
tag = __sbitmap_queue_get(bt);
|
|
if (tag == BLK_MQ_NO_TAG)
|
|
return false;
|
|
|
|
rq->tag = tag + tag_offset;
|
|
return true;
|
|
}
|
|
|
|
bool __blk_mq_get_driver_tag(struct blk_mq_hw_ctx *hctx, struct request *rq)
|
|
{
|
|
if (rq->tag == BLK_MQ_NO_TAG && !__blk_mq_alloc_driver_tag(rq))
|
|
return false;
|
|
|
|
if ((hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED) &&
|
|
!(rq->rq_flags & RQF_MQ_INFLIGHT)) {
|
|
rq->rq_flags |= RQF_MQ_INFLIGHT;
|
|
__blk_mq_inc_active_requests(hctx);
|
|
}
|
|
hctx->tags->rqs[rq->tag] = rq;
|
|
return true;
|
|
}
|
|
|
|
static int blk_mq_dispatch_wake(wait_queue_entry_t *wait, unsigned mode,
|
|
int flags, void *key)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
|
|
hctx = container_of(wait, struct blk_mq_hw_ctx, dispatch_wait);
|
|
|
|
spin_lock(&hctx->dispatch_wait_lock);
|
|
if (!list_empty(&wait->entry)) {
|
|
struct sbitmap_queue *sbq;
|
|
|
|
list_del_init(&wait->entry);
|
|
sbq = &hctx->tags->bitmap_tags;
|
|
atomic_dec(&sbq->ws_active);
|
|
}
|
|
spin_unlock(&hctx->dispatch_wait_lock);
|
|
|
|
blk_mq_run_hw_queue(hctx, true);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Mark us waiting for a tag. For shared tags, this involves hooking us into
|
|
* the tag wakeups. For non-shared tags, we can simply mark us needing a
|
|
* restart. For both cases, take care to check the condition again after
|
|
* marking us as waiting.
|
|
*/
|
|
static bool blk_mq_mark_tag_wait(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq)
|
|
{
|
|
struct sbitmap_queue *sbq = &hctx->tags->bitmap_tags;
|
|
struct wait_queue_head *wq;
|
|
wait_queue_entry_t *wait;
|
|
bool ret;
|
|
|
|
if (!(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
|
|
blk_mq_sched_mark_restart_hctx(hctx);
|
|
|
|
/*
|
|
* It's possible that a tag was freed in the window between the
|
|
* allocation failure and adding the hardware queue to the wait
|
|
* queue.
|
|
*
|
|
* Don't clear RESTART here, someone else could have set it.
|
|
* At most this will cost an extra queue run.
|
|
*/
|
|
return blk_mq_get_driver_tag(rq);
|
|
}
|
|
|
|
wait = &hctx->dispatch_wait;
|
|
if (!list_empty_careful(&wait->entry))
|
|
return false;
|
|
|
|
wq = &bt_wait_ptr(sbq, hctx)->wait;
|
|
|
|
spin_lock_irq(&wq->lock);
|
|
spin_lock(&hctx->dispatch_wait_lock);
|
|
if (!list_empty(&wait->entry)) {
|
|
spin_unlock(&hctx->dispatch_wait_lock);
|
|
spin_unlock_irq(&wq->lock);
|
|
return false;
|
|
}
|
|
|
|
atomic_inc(&sbq->ws_active);
|
|
wait->flags &= ~WQ_FLAG_EXCLUSIVE;
|
|
__add_wait_queue(wq, wait);
|
|
|
|
/*
|
|
* It's possible that a tag was freed in the window between the
|
|
* allocation failure and adding the hardware queue to the wait
|
|
* queue.
|
|
*/
|
|
ret = blk_mq_get_driver_tag(rq);
|
|
if (!ret) {
|
|
spin_unlock(&hctx->dispatch_wait_lock);
|
|
spin_unlock_irq(&wq->lock);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* We got a tag, remove ourselves from the wait queue to ensure
|
|
* someone else gets the wakeup.
|
|
*/
|
|
list_del_init(&wait->entry);
|
|
atomic_dec(&sbq->ws_active);
|
|
spin_unlock(&hctx->dispatch_wait_lock);
|
|
spin_unlock_irq(&wq->lock);
|
|
|
|
return true;
|
|
}
|
|
|
|
#define BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT 8
|
|
#define BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR 4
|
|
/*
|
|
* Update dispatch busy with the Exponential Weighted Moving Average(EWMA):
|
|
* - EWMA is one simple way to compute running average value
|
|
* - weight(7/8 and 1/8) is applied so that it can decrease exponentially
|
|
* - take 4 as factor for avoiding to get too small(0) result, and this
|
|
* factor doesn't matter because EWMA decreases exponentially
|
|
*/
|
|
static void blk_mq_update_dispatch_busy(struct blk_mq_hw_ctx *hctx, bool busy)
|
|
{
|
|
unsigned int ewma;
|
|
|
|
ewma = hctx->dispatch_busy;
|
|
|
|
if (!ewma && !busy)
|
|
return;
|
|
|
|
ewma *= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT - 1;
|
|
if (busy)
|
|
ewma += 1 << BLK_MQ_DISPATCH_BUSY_EWMA_FACTOR;
|
|
ewma /= BLK_MQ_DISPATCH_BUSY_EWMA_WEIGHT;
|
|
|
|
hctx->dispatch_busy = ewma;
|
|
}
|
|
|
|
#define BLK_MQ_RESOURCE_DELAY 3 /* ms units */
|
|
|
|
static void blk_mq_handle_dev_resource(struct request *rq,
|
|
struct list_head *list)
|
|
{
|
|
struct request *next =
|
|
list_first_entry_or_null(list, struct request, queuelist);
|
|
|
|
/*
|
|
* If an I/O scheduler has been configured and we got a driver tag for
|
|
* the next request already, free it.
|
|
*/
|
|
if (next)
|
|
blk_mq_put_driver_tag(next);
|
|
|
|
list_add(&rq->queuelist, list);
|
|
__blk_mq_requeue_request(rq);
|
|
}
|
|
|
|
static void blk_mq_handle_zone_resource(struct request *rq,
|
|
struct list_head *zone_list)
|
|
{
|
|
/*
|
|
* If we end up here it is because we cannot dispatch a request to a
|
|
* specific zone due to LLD level zone-write locking or other zone
|
|
* related resource not being available. In this case, set the request
|
|
* aside in zone_list for retrying it later.
|
|
*/
|
|
list_add(&rq->queuelist, zone_list);
|
|
__blk_mq_requeue_request(rq);
|
|
}
|
|
|
|
enum prep_dispatch {
|
|
PREP_DISPATCH_OK,
|
|
PREP_DISPATCH_NO_TAG,
|
|
PREP_DISPATCH_NO_BUDGET,
|
|
};
|
|
|
|
static enum prep_dispatch blk_mq_prep_dispatch_rq(struct request *rq,
|
|
bool need_budget)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
|
|
int budget_token = -1;
|
|
|
|
if (need_budget) {
|
|
budget_token = blk_mq_get_dispatch_budget(rq->q);
|
|
if (budget_token < 0) {
|
|
blk_mq_put_driver_tag(rq);
|
|
return PREP_DISPATCH_NO_BUDGET;
|
|
}
|
|
blk_mq_set_rq_budget_token(rq, budget_token);
|
|
}
|
|
|
|
if (!blk_mq_get_driver_tag(rq)) {
|
|
/*
|
|
* The initial allocation attempt failed, so we need to
|
|
* rerun the hardware queue when a tag is freed. The
|
|
* waitqueue takes care of that. If the queue is run
|
|
* before we add this entry back on the dispatch list,
|
|
* we'll re-run it below.
|
|
*/
|
|
if (!blk_mq_mark_tag_wait(hctx, rq)) {
|
|
/*
|
|
* All budgets not got from this function will be put
|
|
* together during handling partial dispatch
|
|
*/
|
|
if (need_budget)
|
|
blk_mq_put_dispatch_budget(rq->q, budget_token);
|
|
return PREP_DISPATCH_NO_TAG;
|
|
}
|
|
}
|
|
|
|
return PREP_DISPATCH_OK;
|
|
}
|
|
|
|
/* release all allocated budgets before calling to blk_mq_dispatch_rq_list */
|
|
static void blk_mq_release_budgets(struct request_queue *q,
|
|
struct list_head *list)
|
|
{
|
|
struct request *rq;
|
|
|
|
list_for_each_entry(rq, list, queuelist) {
|
|
int budget_token = blk_mq_get_rq_budget_token(rq);
|
|
|
|
if (budget_token >= 0)
|
|
blk_mq_put_dispatch_budget(q, budget_token);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns true if we did some work AND can potentially do more.
|
|
*/
|
|
bool blk_mq_dispatch_rq_list(struct blk_mq_hw_ctx *hctx, struct list_head *list,
|
|
unsigned int nr_budgets)
|
|
{
|
|
enum prep_dispatch prep;
|
|
struct request_queue *q = hctx->queue;
|
|
struct request *rq, *nxt;
|
|
int errors, queued;
|
|
blk_status_t ret = BLK_STS_OK;
|
|
LIST_HEAD(zone_list);
|
|
bool needs_resource = false;
|
|
|
|
if (list_empty(list))
|
|
return false;
|
|
|
|
/*
|
|
* Now process all the entries, sending them to the driver.
|
|
*/
|
|
errors = queued = 0;
|
|
do {
|
|
struct blk_mq_queue_data bd;
|
|
|
|
rq = list_first_entry(list, struct request, queuelist);
|
|
|
|
WARN_ON_ONCE(hctx != rq->mq_hctx);
|
|
prep = blk_mq_prep_dispatch_rq(rq, !nr_budgets);
|
|
if (prep != PREP_DISPATCH_OK)
|
|
break;
|
|
|
|
list_del_init(&rq->queuelist);
|
|
|
|
bd.rq = rq;
|
|
|
|
/*
|
|
* Flag last if we have no more requests, or if we have more
|
|
* but can't assign a driver tag to it.
|
|
*/
|
|
if (list_empty(list))
|
|
bd.last = true;
|
|
else {
|
|
nxt = list_first_entry(list, struct request, queuelist);
|
|
bd.last = !blk_mq_get_driver_tag(nxt);
|
|
}
|
|
|
|
/*
|
|
* once the request is queued to lld, no need to cover the
|
|
* budget any more
|
|
*/
|
|
if (nr_budgets)
|
|
nr_budgets--;
|
|
ret = q->mq_ops->queue_rq(hctx, &bd);
|
|
switch (ret) {
|
|
case BLK_STS_OK:
|
|
queued++;
|
|
break;
|
|
case BLK_STS_RESOURCE:
|
|
needs_resource = true;
|
|
fallthrough;
|
|
case BLK_STS_DEV_RESOURCE:
|
|
blk_mq_handle_dev_resource(rq, list);
|
|
goto out;
|
|
case BLK_STS_ZONE_RESOURCE:
|
|
/*
|
|
* Move the request to zone_list and keep going through
|
|
* the dispatch list to find more requests the drive can
|
|
* accept.
|
|
*/
|
|
blk_mq_handle_zone_resource(rq, &zone_list);
|
|
needs_resource = true;
|
|
break;
|
|
default:
|
|
errors++;
|
|
blk_mq_end_request(rq, ret);
|
|
}
|
|
} while (!list_empty(list));
|
|
out:
|
|
if (!list_empty(&zone_list))
|
|
list_splice_tail_init(&zone_list, list);
|
|
|
|
/* If we didn't flush the entire list, we could have told the driver
|
|
* there was more coming, but that turned out to be a lie.
|
|
*/
|
|
if ((!list_empty(list) || errors) && q->mq_ops->commit_rqs && queued)
|
|
q->mq_ops->commit_rqs(hctx);
|
|
/*
|
|
* Any items that need requeuing? Stuff them into hctx->dispatch,
|
|
* that is where we will continue on next queue run.
|
|
*/
|
|
if (!list_empty(list)) {
|
|
bool needs_restart;
|
|
/* For non-shared tags, the RESTART check will suffice */
|
|
bool no_tag = prep == PREP_DISPATCH_NO_TAG &&
|
|
(hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED);
|
|
|
|
if (nr_budgets)
|
|
blk_mq_release_budgets(q, list);
|
|
|
|
spin_lock(&hctx->lock);
|
|
list_splice_tail_init(list, &hctx->dispatch);
|
|
spin_unlock(&hctx->lock);
|
|
|
|
/*
|
|
* Order adding requests to hctx->dispatch and checking
|
|
* SCHED_RESTART flag. The pair of this smp_mb() is the one
|
|
* in blk_mq_sched_restart(). Avoid restart code path to
|
|
* miss the new added requests to hctx->dispatch, meantime
|
|
* SCHED_RESTART is observed here.
|
|
*/
|
|
smp_mb();
|
|
|
|
/*
|
|
* If SCHED_RESTART was set by the caller of this function and
|
|
* it is no longer set that means that it was cleared by another
|
|
* thread and hence that a queue rerun is needed.
|
|
*
|
|
* If 'no_tag' is set, that means that we failed getting
|
|
* a driver tag with an I/O scheduler attached. If our dispatch
|
|
* waitqueue is no longer active, ensure that we run the queue
|
|
* AFTER adding our entries back to the list.
|
|
*
|
|
* If no I/O scheduler has been configured it is possible that
|
|
* the hardware queue got stopped and restarted before requests
|
|
* were pushed back onto the dispatch list. Rerun the queue to
|
|
* avoid starvation. Notes:
|
|
* - 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_STS_RESOURCE. Two exceptions are scsi-mq
|
|
* and dm-rq.
|
|
*
|
|
* If driver returns BLK_STS_RESOURCE and SCHED_RESTART
|
|
* bit is set, run queue after a delay to avoid IO stalls
|
|
* that could otherwise occur if the queue is idle. We'll do
|
|
* similar if we couldn't get budget or couldn't lock a zone
|
|
* and SCHED_RESTART is set.
|
|
*/
|
|
needs_restart = blk_mq_sched_needs_restart(hctx);
|
|
if (prep == PREP_DISPATCH_NO_BUDGET)
|
|
needs_resource = true;
|
|
if (!needs_restart ||
|
|
(no_tag && list_empty_careful(&hctx->dispatch_wait.entry)))
|
|
blk_mq_run_hw_queue(hctx, true);
|
|
else if (needs_restart && needs_resource)
|
|
blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
|
|
|
|
blk_mq_update_dispatch_busy(hctx, true);
|
|
return false;
|
|
} else
|
|
blk_mq_update_dispatch_busy(hctx, false);
|
|
|
|
return (queued + errors) != 0;
|
|
}
|
|
|
|
/**
|
|
* __blk_mq_run_hw_queue - Run a hardware queue.
|
|
* @hctx: Pointer to the hardware queue to run.
|
|
*
|
|
* Send pending requests to the hardware.
|
|
*/
|
|
static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
/*
|
|
* We can't run the queue inline with ints disabled. Ensure that
|
|
* we catch bad users of this early.
|
|
*/
|
|
WARN_ON_ONCE(in_interrupt());
|
|
|
|
blk_mq_run_dispatch_ops(hctx->queue,
|
|
blk_mq_sched_dispatch_requests(hctx));
|
|
}
|
|
|
|
static inline int blk_mq_first_mapped_cpu(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
int cpu = cpumask_first_and(hctx->cpumask, cpu_online_mask);
|
|
|
|
if (cpu >= nr_cpu_ids)
|
|
cpu = cpumask_first(hctx->cpumask);
|
|
return cpu;
|
|
}
|
|
|
|
/*
|
|
* It'd be great if the workqueue API had a way to pass
|
|
* in a mask and had some smarts for more clever placement.
|
|
* For now we just round-robin here, switching for every
|
|
* BLK_MQ_CPU_WORK_BATCH queued items.
|
|
*/
|
|
static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
bool tried = false;
|
|
int next_cpu = hctx->next_cpu;
|
|
|
|
if (hctx->queue->nr_hw_queues == 1)
|
|
return WORK_CPU_UNBOUND;
|
|
|
|
if (--hctx->next_cpu_batch <= 0) {
|
|
select_cpu:
|
|
next_cpu = cpumask_next_and(next_cpu, hctx->cpumask,
|
|
cpu_online_mask);
|
|
if (next_cpu >= nr_cpu_ids)
|
|
next_cpu = blk_mq_first_mapped_cpu(hctx);
|
|
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
|
|
}
|
|
|
|
/*
|
|
* Do unbound schedule if we can't find a online CPU for this hctx,
|
|
* and it should only happen in the path of handling CPU DEAD.
|
|
*/
|
|
if (!cpu_online(next_cpu)) {
|
|
if (!tried) {
|
|
tried = true;
|
|
goto select_cpu;
|
|
}
|
|
|
|
/*
|
|
* Make sure to re-select CPU next time once after CPUs
|
|
* in hctx->cpumask become online again.
|
|
*/
|
|
hctx->next_cpu = next_cpu;
|
|
hctx->next_cpu_batch = 1;
|
|
return WORK_CPU_UNBOUND;
|
|
}
|
|
|
|
hctx->next_cpu = next_cpu;
|
|
return next_cpu;
|
|
}
|
|
|
|
/**
|
|
* __blk_mq_delay_run_hw_queue - Run (or schedule to run) a hardware queue.
|
|
* @hctx: Pointer to the hardware queue to run.
|
|
* @async: If we want to run the queue asynchronously.
|
|
* @msecs: Milliseconds of delay to wait before running the queue.
|
|
*
|
|
* If !@async, try to run the queue now. Else, run the queue asynchronously and
|
|
* with a delay of @msecs.
|
|
*/
|
|
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)))
|
|
return;
|
|
|
|
if (!async && !(hctx->flags & BLK_MQ_F_BLOCKING)) {
|
|
int cpu = get_cpu();
|
|
if (cpumask_test_cpu(cpu, hctx->cpumask)) {
|
|
__blk_mq_run_hw_queue(hctx);
|
|
put_cpu();
|
|
return;
|
|
}
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
kblockd_mod_delayed_work_on(blk_mq_hctx_next_cpu(hctx), &hctx->run_work,
|
|
msecs_to_jiffies(msecs));
|
|
}
|
|
|
|
/**
|
|
* blk_mq_delay_run_hw_queue - Run a hardware queue asynchronously.
|
|
* @hctx: Pointer to the hardware queue to run.
|
|
* @msecs: Milliseconds of delay to wait before running the queue.
|
|
*
|
|
* Run a hardware queue asynchronously with a delay of @msecs.
|
|
*/
|
|
void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
|
|
{
|
|
__blk_mq_delay_run_hw_queue(hctx, true, msecs);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_delay_run_hw_queue);
|
|
|
|
/**
|
|
* blk_mq_run_hw_queue - Start to run a hardware queue.
|
|
* @hctx: Pointer to the hardware queue to run.
|
|
* @async: If we want to run the queue asynchronously.
|
|
*
|
|
* Check if the request queue is not in a quiesced state and if there are
|
|
* pending requests to be sent. If this is true, run the queue to send requests
|
|
* to hardware.
|
|
*/
|
|
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
|
|
{
|
|
bool need_run;
|
|
|
|
/*
|
|
* When queue is quiesced, we may be switching io scheduler, or
|
|
* updating nr_hw_queues, or other things, and we can't run queue
|
|
* any more, even __blk_mq_hctx_has_pending() can't be called safely.
|
|
*
|
|
* And queue will be rerun in blk_mq_unquiesce_queue() if it is
|
|
* quiesced.
|
|
*/
|
|
__blk_mq_run_dispatch_ops(hctx->queue, false,
|
|
need_run = !blk_queue_quiesced(hctx->queue) &&
|
|
blk_mq_hctx_has_pending(hctx));
|
|
|
|
if (need_run)
|
|
__blk_mq_delay_run_hw_queue(hctx, async, 0);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_run_hw_queue);
|
|
|
|
/*
|
|
* Is the request queue handled by an IO scheduler that does not respect
|
|
* hardware queues when dispatching?
|
|
*/
|
|
static bool blk_mq_has_sqsched(struct request_queue *q)
|
|
{
|
|
struct elevator_queue *e = q->elevator;
|
|
|
|
if (e && e->type->ops.dispatch_request &&
|
|
!(e->type->elevator_features & ELEVATOR_F_MQ_AWARE))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Return prefered queue to dispatch from (if any) for non-mq aware IO
|
|
* scheduler.
|
|
*/
|
|
static struct blk_mq_hw_ctx *blk_mq_get_sq_hctx(struct request_queue *q)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
|
|
/*
|
|
* If the IO scheduler does not respect hardware queues when
|
|
* dispatching, we just don't bother with multiple HW queues and
|
|
* dispatch from hctx for the current CPU since running multiple queues
|
|
* just causes lock contention inside the scheduler and pointless cache
|
|
* bouncing.
|
|
*/
|
|
hctx = blk_mq_map_queue_type(q, HCTX_TYPE_DEFAULT,
|
|
raw_smp_processor_id());
|
|
if (!blk_mq_hctx_stopped(hctx))
|
|
return hctx;
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* blk_mq_run_hw_queues - Run all hardware queues in a request queue.
|
|
* @q: Pointer to the request queue to run.
|
|
* @async: If we want to run the queue asynchronously.
|
|
*/
|
|
void blk_mq_run_hw_queues(struct request_queue *q, bool async)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx, *sq_hctx;
|
|
int i;
|
|
|
|
sq_hctx = NULL;
|
|
if (blk_mq_has_sqsched(q))
|
|
sq_hctx = blk_mq_get_sq_hctx(q);
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (blk_mq_hctx_stopped(hctx))
|
|
continue;
|
|
/*
|
|
* Dispatch from this hctx either if there's no hctx preferred
|
|
* by IO scheduler or if it has requests that bypass the
|
|
* scheduler.
|
|
*/
|
|
if (!sq_hctx || sq_hctx == hctx ||
|
|
!list_empty_careful(&hctx->dispatch))
|
|
blk_mq_run_hw_queue(hctx, async);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_run_hw_queues);
|
|
|
|
/**
|
|
* blk_mq_delay_run_hw_queues - Run all hardware queues asynchronously.
|
|
* @q: Pointer to the request queue to run.
|
|
* @msecs: Milliseconds of delay to wait before running the queues.
|
|
*/
|
|
void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx, *sq_hctx;
|
|
int i;
|
|
|
|
sq_hctx = NULL;
|
|
if (blk_mq_has_sqsched(q))
|
|
sq_hctx = blk_mq_get_sq_hctx(q);
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (blk_mq_hctx_stopped(hctx))
|
|
continue;
|
|
/*
|
|
* Dispatch from this hctx either if there's no hctx preferred
|
|
* by IO scheduler or if it has requests that bypass the
|
|
* scheduler.
|
|
*/
|
|
if (!sq_hctx || sq_hctx == hctx ||
|
|
!list_empty_careful(&hctx->dispatch))
|
|
blk_mq_delay_run_hw_queue(hctx, msecs);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_delay_run_hw_queues);
|
|
|
|
/**
|
|
* blk_mq_queue_stopped() - check whether one or more hctxs have been stopped
|
|
* @q: request queue.
|
|
*
|
|
* The caller is responsible for serializing this function against
|
|
* blk_mq_{start,stop}_hw_queue().
|
|
*/
|
|
bool blk_mq_queue_stopped(struct request_queue *q)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
if (blk_mq_hctx_stopped(hctx))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_queue_stopped);
|
|
|
|
/*
|
|
* 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_STS_RESOURCE 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)
|
|
{
|
|
cancel_delayed_work(&hctx->run_work);
|
|
|
|
set_bit(BLK_MQ_S_STOPPED, &hctx->state);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_stop_hw_queue);
|
|
|
|
/*
|
|
* 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_STS_RESOURCE 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);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_stop_hw_queues);
|
|
|
|
void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
|
|
|
|
blk_mq_run_hw_queue(hctx, false);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_start_hw_queue);
|
|
|
|
void blk_mq_start_hw_queues(struct request_queue *q)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
blk_mq_start_hw_queue(hctx);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_start_hw_queues);
|
|
|
|
void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
|
|
{
|
|
if (!blk_mq_hctx_stopped(hctx))
|
|
return;
|
|
|
|
clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
|
|
blk_mq_run_hw_queue(hctx, async);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_start_stopped_hw_queue);
|
|
|
|
void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
blk_mq_start_stopped_hw_queue(hctx, async);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
|
|
|
|
static void blk_mq_run_work_fn(struct work_struct *work)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
|
|
hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
|
|
|
|
/*
|
|
* If we are stopped, don't run the queue.
|
|
*/
|
|
if (blk_mq_hctx_stopped(hctx))
|
|
return;
|
|
|
|
__blk_mq_run_hw_queue(hctx);
|
|
}
|
|
|
|
static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq,
|
|
bool at_head)
|
|
{
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx;
|
|
enum hctx_type type = hctx->type;
|
|
|
|
lockdep_assert_held(&ctx->lock);
|
|
|
|
trace_block_rq_insert(rq);
|
|
|
|
if (at_head)
|
|
list_add(&rq->queuelist, &ctx->rq_lists[type]);
|
|
else
|
|
list_add_tail(&rq->queuelist, &ctx->rq_lists[type]);
|
|
}
|
|
|
|
void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx, struct request *rq,
|
|
bool 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_mq_request_bypass_insert - Insert a request at dispatch list.
|
|
* @rq: Pointer to request to be inserted.
|
|
* @at_head: true if the request should be inserted at the head of the list.
|
|
* @run_queue: If we should run the hardware queue after inserting the request.
|
|
*
|
|
* Should only be used carefully, when the caller knows we want to
|
|
* bypass a potential IO scheduler on the target device.
|
|
*/
|
|
void blk_mq_request_bypass_insert(struct request *rq, bool at_head,
|
|
bool run_queue)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = rq->mq_hctx;
|
|
|
|
spin_lock(&hctx->lock);
|
|
if (at_head)
|
|
list_add(&rq->queuelist, &hctx->dispatch);
|
|
else
|
|
list_add_tail(&rq->queuelist, &hctx->dispatch);
|
|
spin_unlock(&hctx->lock);
|
|
|
|
if (run_queue)
|
|
blk_mq_run_hw_queue(hctx, false);
|
|
}
|
|
|
|
void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx,
|
|
struct list_head *list)
|
|
|
|
{
|
|
struct request *rq;
|
|
enum hctx_type type = hctx->type;
|
|
|
|
/*
|
|
* preemption doesn't flush plug list, so it's possible ctx->cpu is
|
|
* offline now
|
|
*/
|
|
list_for_each_entry(rq, list, queuelist) {
|
|
BUG_ON(rq->mq_ctx != ctx);
|
|
trace_block_rq_insert(rq);
|
|
}
|
|
|
|
spin_lock(&ctx->lock);
|
|
list_splice_tail_init(list, &ctx->rq_lists[type]);
|
|
blk_mq_hctx_mark_pending(hctx, ctx);
|
|
spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
static void blk_mq_commit_rqs(struct blk_mq_hw_ctx *hctx, int *queued,
|
|
bool from_schedule)
|
|
{
|
|
if (hctx->queue->mq_ops->commit_rqs) {
|
|
trace_block_unplug(hctx->queue, *queued, !from_schedule);
|
|
hctx->queue->mq_ops->commit_rqs(hctx);
|
|
}
|
|
*queued = 0;
|
|
}
|
|
|
|
static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
|
|
unsigned int nr_segs)
|
|
{
|
|
int err;
|
|
|
|
if (bio->bi_opf & REQ_RAHEAD)
|
|
rq->cmd_flags |= REQ_FAILFAST_MASK;
|
|
|
|
rq->__sector = bio->bi_iter.bi_sector;
|
|
rq->write_hint = bio->bi_write_hint;
|
|
blk_rq_bio_prep(rq, bio, nr_segs);
|
|
|
|
/* This can't fail, since GFP_NOIO includes __GFP_DIRECT_RECLAIM. */
|
|
err = blk_crypto_rq_bio_prep(rq, bio, GFP_NOIO);
|
|
WARN_ON_ONCE(err);
|
|
|
|
blk_account_io_start(rq);
|
|
}
|
|
|
|
static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq, bool last)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
struct blk_mq_queue_data bd = {
|
|
.rq = rq,
|
|
.last = last,
|
|
};
|
|
blk_status_t ret;
|
|
|
|
/*
|
|
* For OK queue, we are done. For error, caller may kill it.
|
|
* Any other error (busy), just add it to our list as we
|
|
* previously would have done.
|
|
*/
|
|
ret = q->mq_ops->queue_rq(hctx, &bd);
|
|
switch (ret) {
|
|
case BLK_STS_OK:
|
|
blk_mq_update_dispatch_busy(hctx, false);
|
|
break;
|
|
case BLK_STS_RESOURCE:
|
|
case BLK_STS_DEV_RESOURCE:
|
|
blk_mq_update_dispatch_busy(hctx, true);
|
|
__blk_mq_requeue_request(rq);
|
|
break;
|
|
default:
|
|
blk_mq_update_dispatch_busy(hctx, false);
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq,
|
|
bool bypass_insert, bool last)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
bool run_queue = true;
|
|
int budget_token;
|
|
|
|
/*
|
|
* RCU or SRCU read lock is needed before checking quiesced flag.
|
|
*
|
|
* When queue is stopped or quiesced, ignore 'bypass_insert' from
|
|
* blk_mq_request_issue_directly(), and return BLK_STS_OK to caller,
|
|
* and avoid driver to try to dispatch again.
|
|
*/
|
|
if (blk_mq_hctx_stopped(hctx) || blk_queue_quiesced(q)) {
|
|
run_queue = false;
|
|
bypass_insert = false;
|
|
goto insert;
|
|
}
|
|
|
|
if ((rq->rq_flags & RQF_ELV) && !bypass_insert)
|
|
goto insert;
|
|
|
|
budget_token = blk_mq_get_dispatch_budget(q);
|
|
if (budget_token < 0)
|
|
goto insert;
|
|
|
|
blk_mq_set_rq_budget_token(rq, budget_token);
|
|
|
|
if (!blk_mq_get_driver_tag(rq)) {
|
|
blk_mq_put_dispatch_budget(q, budget_token);
|
|
goto insert;
|
|
}
|
|
|
|
return __blk_mq_issue_directly(hctx, rq, last);
|
|
insert:
|
|
if (bypass_insert)
|
|
return BLK_STS_RESOURCE;
|
|
|
|
blk_mq_sched_insert_request(rq, false, run_queue, false);
|
|
|
|
return BLK_STS_OK;
|
|
}
|
|
|
|
/**
|
|
* blk_mq_try_issue_directly - Try to send a request directly to device driver.
|
|
* @hctx: Pointer of the associated hardware queue.
|
|
* @rq: Pointer to request to be sent.
|
|
*
|
|
* If the device has enough resources to accept a new request now, send the
|
|
* request directly to device driver. Else, insert at hctx->dispatch queue, so
|
|
* we can try send it another time in the future. Requests inserted at this
|
|
* queue have higher priority.
|
|
*/
|
|
static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq)
|
|
{
|
|
blk_status_t ret =
|
|
__blk_mq_try_issue_directly(hctx, rq, false, true);
|
|
|
|
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE)
|
|
blk_mq_request_bypass_insert(rq, false, true);
|
|
else if (ret != BLK_STS_OK)
|
|
blk_mq_end_request(rq, ret);
|
|
}
|
|
|
|
static blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
|
|
{
|
|
return __blk_mq_try_issue_directly(rq->mq_hctx, rq, true, last);
|
|
}
|
|
|
|
static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = NULL;
|
|
struct request *rq;
|
|
int queued = 0;
|
|
int errors = 0;
|
|
|
|
while ((rq = rq_list_pop(&plug->mq_list))) {
|
|
bool last = rq_list_empty(plug->mq_list);
|
|
blk_status_t ret;
|
|
|
|
if (hctx != rq->mq_hctx) {
|
|
if (hctx)
|
|
blk_mq_commit_rqs(hctx, &queued, from_schedule);
|
|
hctx = rq->mq_hctx;
|
|
}
|
|
|
|
ret = blk_mq_request_issue_directly(rq, last);
|
|
switch (ret) {
|
|
case BLK_STS_OK:
|
|
queued++;
|
|
break;
|
|
case BLK_STS_RESOURCE:
|
|
case BLK_STS_DEV_RESOURCE:
|
|
blk_mq_request_bypass_insert(rq, false, last);
|
|
blk_mq_commit_rqs(hctx, &queued, from_schedule);
|
|
return;
|
|
default:
|
|
blk_mq_end_request(rq, ret);
|
|
errors++;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If we didn't flush the entire list, we could have told the driver
|
|
* there was more coming, but that turned out to be a lie.
|
|
*/
|
|
if (errors)
|
|
blk_mq_commit_rqs(hctx, &queued, from_schedule);
|
|
}
|
|
|
|
static void __blk_mq_flush_plug_list(struct request_queue *q,
|
|
struct blk_plug *plug)
|
|
{
|
|
if (blk_queue_quiesced(q))
|
|
return;
|
|
q->mq_ops->queue_rqs(&plug->mq_list);
|
|
}
|
|
|
|
void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
|
|
{
|
|
struct blk_mq_hw_ctx *this_hctx;
|
|
struct blk_mq_ctx *this_ctx;
|
|
struct request *rq;
|
|
unsigned int depth;
|
|
LIST_HEAD(list);
|
|
|
|
if (rq_list_empty(plug->mq_list))
|
|
return;
|
|
plug->rq_count = 0;
|
|
|
|
if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
|
|
struct request_queue *q;
|
|
|
|
rq = rq_list_peek(&plug->mq_list);
|
|
q = rq->q;
|
|
|
|
/*
|
|
* Peek first request and see if we have a ->queue_rqs() hook.
|
|
* If we do, we can dispatch the whole plug list in one go. We
|
|
* already know at this point that all requests belong to the
|
|
* same queue, caller must ensure that's the case.
|
|
*
|
|
* Since we pass off the full list to the driver at this point,
|
|
* we do not increment the active request count for the queue.
|
|
* Bypass shared tags for now because of that.
|
|
*/
|
|
if (q->mq_ops->queue_rqs &&
|
|
!(rq->mq_hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
|
|
blk_mq_run_dispatch_ops(q,
|
|
__blk_mq_flush_plug_list(q, plug));
|
|
if (rq_list_empty(plug->mq_list))
|
|
return;
|
|
}
|
|
|
|
blk_mq_run_dispatch_ops(q,
|
|
blk_mq_plug_issue_direct(plug, false));
|
|
if (rq_list_empty(plug->mq_list))
|
|
return;
|
|
}
|
|
|
|
this_hctx = NULL;
|
|
this_ctx = NULL;
|
|
depth = 0;
|
|
do {
|
|
rq = rq_list_pop(&plug->mq_list);
|
|
|
|
if (!this_hctx) {
|
|
this_hctx = rq->mq_hctx;
|
|
this_ctx = rq->mq_ctx;
|
|
} else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) {
|
|
trace_block_unplug(this_hctx->queue, depth,
|
|
!from_schedule);
|
|
blk_mq_sched_insert_requests(this_hctx, this_ctx,
|
|
&list, from_schedule);
|
|
depth = 0;
|
|
this_hctx = rq->mq_hctx;
|
|
this_ctx = rq->mq_ctx;
|
|
|
|
}
|
|
|
|
list_add(&rq->queuelist, &list);
|
|
depth++;
|
|
} while (!rq_list_empty(plug->mq_list));
|
|
|
|
if (!list_empty(&list)) {
|
|
trace_block_unplug(this_hctx->queue, depth, !from_schedule);
|
|
blk_mq_sched_insert_requests(this_hctx, this_ctx, &list,
|
|
from_schedule);
|
|
}
|
|
}
|
|
|
|
void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct list_head *list)
|
|
{
|
|
int queued = 0;
|
|
int errors = 0;
|
|
|
|
while (!list_empty(list)) {
|
|
blk_status_t ret;
|
|
struct request *rq = list_first_entry(list, struct request,
|
|
queuelist);
|
|
|
|
list_del_init(&rq->queuelist);
|
|
ret = blk_mq_request_issue_directly(rq, list_empty(list));
|
|
if (ret != BLK_STS_OK) {
|
|
if (ret == BLK_STS_RESOURCE ||
|
|
ret == BLK_STS_DEV_RESOURCE) {
|
|
blk_mq_request_bypass_insert(rq, false,
|
|
list_empty(list));
|
|
break;
|
|
}
|
|
blk_mq_end_request(rq, ret);
|
|
errors++;
|
|
} else
|
|
queued++;
|
|
}
|
|
|
|
/*
|
|
* If we didn't flush the entire list, we could have told
|
|
* the driver there was more coming, but that turned out to
|
|
* be a lie.
|
|
*/
|
|
if ((!list_empty(list) || errors) &&
|
|
hctx->queue->mq_ops->commit_rqs && queued)
|
|
hctx->queue->mq_ops->commit_rqs(hctx);
|
|
}
|
|
|
|
/*
|
|
* Allow 2x BLK_MAX_REQUEST_COUNT requests on plug queue for multiple
|
|
* queues. This is important for md arrays to benefit from merging
|
|
* requests.
|
|
*/
|
|
static inline unsigned short blk_plug_max_rq_count(struct blk_plug *plug)
|
|
{
|
|
if (plug->multiple_queues)
|
|
return BLK_MAX_REQUEST_COUNT * 2;
|
|
return BLK_MAX_REQUEST_COUNT;
|
|
}
|
|
|
|
static void blk_add_rq_to_plug(struct blk_plug *plug, struct request *rq)
|
|
{
|
|
struct request *last = rq_list_peek(&plug->mq_list);
|
|
|
|
if (!plug->rq_count) {
|
|
trace_block_plug(rq->q);
|
|
} else if (plug->rq_count >= blk_plug_max_rq_count(plug) ||
|
|
(!blk_queue_nomerges(rq->q) &&
|
|
blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
|
|
blk_mq_flush_plug_list(plug, false);
|
|
trace_block_plug(rq->q);
|
|
}
|
|
|
|
if (!plug->multiple_queues && last && last->q != rq->q)
|
|
plug->multiple_queues = true;
|
|
if (!plug->has_elevator && (rq->rq_flags & RQF_ELV))
|
|
plug->has_elevator = true;
|
|
rq->rq_next = NULL;
|
|
rq_list_add(&plug->mq_list, rq);
|
|
plug->rq_count++;
|
|
}
|
|
|
|
static bool blk_mq_attempt_bio_merge(struct request_queue *q,
|
|
struct bio *bio, unsigned int nr_segs)
|
|
{
|
|
if (!blk_queue_nomerges(q) && bio_mergeable(bio)) {
|
|
if (blk_attempt_plug_merge(q, bio, nr_segs))
|
|
return true;
|
|
if (blk_mq_sched_bio_merge(q, bio, nr_segs))
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static struct request *blk_mq_get_new_requests(struct request_queue *q,
|
|
struct blk_plug *plug,
|
|
struct bio *bio)
|
|
{
|
|
struct blk_mq_alloc_data data = {
|
|
.q = q,
|
|
.nr_tags = 1,
|
|
.cmd_flags = bio->bi_opf,
|
|
};
|
|
struct request *rq;
|
|
|
|
if (unlikely(bio_queue_enter(bio)))
|
|
return NULL;
|
|
|
|
if (plug) {
|
|
data.nr_tags = plug->nr_ios;
|
|
plug->nr_ios = 1;
|
|
data.cached_rq = &plug->cached_rq;
|
|
}
|
|
|
|
rq = __blk_mq_alloc_requests(&data);
|
|
if (rq)
|
|
return rq;
|
|
rq_qos_cleanup(q, bio);
|
|
if (bio->bi_opf & REQ_NOWAIT)
|
|
bio_wouldblock_error(bio);
|
|
blk_queue_exit(q);
|
|
return NULL;
|
|
}
|
|
|
|
static inline struct request *blk_mq_get_cached_request(struct request_queue *q,
|
|
struct blk_plug *plug, struct bio *bio)
|
|
{
|
|
struct request *rq;
|
|
|
|
if (!plug)
|
|
return NULL;
|
|
rq = rq_list_peek(&plug->cached_rq);
|
|
if (!rq || rq->q != q)
|
|
return NULL;
|
|
|
|
if (blk_mq_get_hctx_type(bio->bi_opf) != rq->mq_hctx->type)
|
|
return NULL;
|
|
if (op_is_flush(rq->cmd_flags) != op_is_flush(bio->bi_opf))
|
|
return NULL;
|
|
|
|
rq->cmd_flags = bio->bi_opf;
|
|
plug->cached_rq = rq_list_next(rq);
|
|
INIT_LIST_HEAD(&rq->queuelist);
|
|
return rq;
|
|
}
|
|
|
|
/**
|
|
* blk_mq_submit_bio - Create and send a request to block device.
|
|
* @bio: Bio pointer.
|
|
*
|
|
* Builds up a request structure from @q and @bio and send to the device. The
|
|
* request may not be queued directly to hardware if:
|
|
* * This request can be merged with another one
|
|
* * We want to place request at plug queue for possible future merging
|
|
* * There is an IO scheduler active at this queue
|
|
*
|
|
* It will not queue the request if there is an error with the bio, or at the
|
|
* request creation.
|
|
*/
|
|
void blk_mq_submit_bio(struct bio *bio)
|
|
{
|
|
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
|
|
struct blk_plug *plug = blk_mq_plug(q, bio);
|
|
const int is_sync = op_is_sync(bio->bi_opf);
|
|
struct request *rq;
|
|
unsigned int nr_segs = 1;
|
|
blk_status_t ret;
|
|
|
|
if (unlikely(!blk_crypto_bio_prep(&bio)))
|
|
return;
|
|
|
|
blk_queue_bounce(q, &bio);
|
|
if (blk_may_split(q, bio))
|
|
__blk_queue_split(q, &bio, &nr_segs);
|
|
|
|
if (!bio_integrity_prep(bio))
|
|
return;
|
|
|
|
if (blk_mq_attempt_bio_merge(q, bio, nr_segs))
|
|
return;
|
|
|
|
rq_qos_throttle(q, bio);
|
|
|
|
rq = blk_mq_get_cached_request(q, plug, bio);
|
|
if (!rq) {
|
|
rq = blk_mq_get_new_requests(q, plug, bio);
|
|
if (unlikely(!rq))
|
|
return;
|
|
}
|
|
|
|
trace_block_getrq(bio);
|
|
|
|
rq_qos_track(q, rq, bio);
|
|
|
|
blk_mq_bio_to_request(rq, bio, nr_segs);
|
|
|
|
ret = blk_crypto_init_request(rq);
|
|
if (ret != BLK_STS_OK) {
|
|
bio->bi_status = ret;
|
|
bio_endio(bio);
|
|
blk_mq_free_request(rq);
|
|
return;
|
|
}
|
|
|
|
if (op_is_flush(bio->bi_opf)) {
|
|
blk_insert_flush(rq);
|
|
return;
|
|
}
|
|
|
|
if (plug)
|
|
blk_add_rq_to_plug(plug, rq);
|
|
else if ((rq->rq_flags & RQF_ELV) ||
|
|
(rq->mq_hctx->dispatch_busy &&
|
|
(q->nr_hw_queues == 1 || !is_sync)))
|
|
blk_mq_sched_insert_request(rq, false, true, true);
|
|
else
|
|
blk_mq_run_dispatch_ops(rq->q,
|
|
blk_mq_try_issue_directly(rq->mq_hctx, rq));
|
|
}
|
|
|
|
/**
|
|
* blk_cloned_rq_check_limits - Helper function to check a cloned request
|
|
* for the new queue limits
|
|
* @q: the queue
|
|
* @rq: the request being checked
|
|
*
|
|
* Description:
|
|
* @rq may have been made based on weaker limitations of upper-level queues
|
|
* in request stacking drivers, and it may violate the limitation of @q.
|
|
* Since the block layer and the underlying device driver trust @rq
|
|
* after it is inserted to @q, it should be checked against @q before
|
|
* the insertion using this generic function.
|
|
*
|
|
* Request stacking drivers like request-based dm may change the queue
|
|
* limits when retrying requests on other queues. Those requests need
|
|
* to be checked against the new queue limits again during dispatch.
|
|
*/
|
|
static blk_status_t blk_cloned_rq_check_limits(struct request_queue *q,
|
|
struct request *rq)
|
|
{
|
|
unsigned int max_sectors = blk_queue_get_max_sectors(q, req_op(rq));
|
|
|
|
if (blk_rq_sectors(rq) > max_sectors) {
|
|
/*
|
|
* SCSI device does not have a good way to return if
|
|
* Write Same/Zero is actually supported. If a device rejects
|
|
* a non-read/write command (discard, write same,etc.) the
|
|
* low-level device driver will set the relevant queue limit to
|
|
* 0 to prevent blk-lib from issuing more of the offending
|
|
* operations. Commands queued prior to the queue limit being
|
|
* reset need to be completed with BLK_STS_NOTSUPP to avoid I/O
|
|
* errors being propagated to upper layers.
|
|
*/
|
|
if (max_sectors == 0)
|
|
return BLK_STS_NOTSUPP;
|
|
|
|
printk(KERN_ERR "%s: over max size limit. (%u > %u)\n",
|
|
__func__, blk_rq_sectors(rq), max_sectors);
|
|
return BLK_STS_IOERR;
|
|
}
|
|
|
|
/*
|
|
* The queue settings related to segment counting may differ from the
|
|
* original queue.
|
|
*/
|
|
rq->nr_phys_segments = blk_recalc_rq_segments(rq);
|
|
if (rq->nr_phys_segments > queue_max_segments(q)) {
|
|
printk(KERN_ERR "%s: over max segments limit. (%hu > %hu)\n",
|
|
__func__, rq->nr_phys_segments, queue_max_segments(q));
|
|
return BLK_STS_IOERR;
|
|
}
|
|
|
|
return BLK_STS_OK;
|
|
}
|
|
|
|
/**
|
|
* blk_insert_cloned_request - Helper for stacking drivers to submit a request
|
|
* @q: the queue to submit the request
|
|
* @rq: the request being queued
|
|
*/
|
|
blk_status_t blk_insert_cloned_request(struct request_queue *q, struct request *rq)
|
|
{
|
|
blk_status_t ret;
|
|
|
|
ret = blk_cloned_rq_check_limits(q, rq);
|
|
if (ret != BLK_STS_OK)
|
|
return ret;
|
|
|
|
if (rq->q->disk &&
|
|
should_fail_request(rq->q->disk->part0, blk_rq_bytes(rq)))
|
|
return BLK_STS_IOERR;
|
|
|
|
if (blk_crypto_insert_cloned_request(rq))
|
|
return BLK_STS_IOERR;
|
|
|
|
blk_account_io_start(rq);
|
|
|
|
/*
|
|
* Since we have a scheduler attached on the top device,
|
|
* bypass a potential scheduler on the bottom device for
|
|
* insert.
|
|
*/
|
|
blk_mq_run_dispatch_ops(rq->q,
|
|
ret = blk_mq_request_issue_directly(rq, true));
|
|
if (ret)
|
|
blk_account_io_done(rq, ktime_get_ns());
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_insert_cloned_request);
|
|
|
|
/**
|
|
* blk_rq_unprep_clone - Helper function to free all bios in a cloned request
|
|
* @rq: the clone request to be cleaned up
|
|
*
|
|
* Description:
|
|
* Free all bios in @rq for a cloned request.
|
|
*/
|
|
void blk_rq_unprep_clone(struct request *rq)
|
|
{
|
|
struct bio *bio;
|
|
|
|
while ((bio = rq->bio) != NULL) {
|
|
rq->bio = bio->bi_next;
|
|
|
|
bio_put(bio);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_rq_unprep_clone);
|
|
|
|
/**
|
|
* blk_rq_prep_clone - Helper function to setup clone request
|
|
* @rq: the request to be setup
|
|
* @rq_src: original request to be cloned
|
|
* @bs: bio_set that bios for clone are allocated from
|
|
* @gfp_mask: memory allocation mask for bio
|
|
* @bio_ctr: setup function to be called for each clone bio.
|
|
* Returns %0 for success, non %0 for failure.
|
|
* @data: private data to be passed to @bio_ctr
|
|
*
|
|
* Description:
|
|
* Clones bios in @rq_src to @rq, and copies attributes of @rq_src to @rq.
|
|
* Also, pages which the original bios are pointing to are not copied
|
|
* and the cloned bios just point same pages.
|
|
* So cloned bios must be completed before original bios, which means
|
|
* the caller must complete @rq before @rq_src.
|
|
*/
|
|
int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
|
|
struct bio_set *bs, gfp_t gfp_mask,
|
|
int (*bio_ctr)(struct bio *, struct bio *, void *),
|
|
void *data)
|
|
{
|
|
struct bio *bio, *bio_src;
|
|
|
|
if (!bs)
|
|
bs = &fs_bio_set;
|
|
|
|
__rq_for_each_bio(bio_src, rq_src) {
|
|
bio = bio_clone_fast(bio_src, gfp_mask, bs);
|
|
if (!bio)
|
|
goto free_and_out;
|
|
bio->bi_bdev = rq->q->disk->part0;
|
|
|
|
if (bio_ctr && bio_ctr(bio, bio_src, data))
|
|
goto free_and_out;
|
|
|
|
if (rq->bio) {
|
|
rq->biotail->bi_next = bio;
|
|
rq->biotail = bio;
|
|
} else {
|
|
rq->bio = rq->biotail = bio;
|
|
}
|
|
bio = NULL;
|
|
}
|
|
|
|
/* Copy attributes of the original request to the clone request. */
|
|
rq->__sector = blk_rq_pos(rq_src);
|
|
rq->__data_len = blk_rq_bytes(rq_src);
|
|
if (rq_src->rq_flags & RQF_SPECIAL_PAYLOAD) {
|
|
rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
|
|
rq->special_vec = rq_src->special_vec;
|
|
}
|
|
rq->nr_phys_segments = rq_src->nr_phys_segments;
|
|
rq->ioprio = rq_src->ioprio;
|
|
|
|
if (rq->bio && blk_crypto_rq_bio_prep(rq, rq->bio, gfp_mask) < 0)
|
|
goto free_and_out;
|
|
|
|
return 0;
|
|
|
|
free_and_out:
|
|
if (bio)
|
|
bio_put(bio);
|
|
blk_rq_unprep_clone(rq);
|
|
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_rq_prep_clone);
|
|
|
|
/*
|
|
* Steal bios from a request and add them to a bio list.
|
|
* The request must not have been partially completed before.
|
|
*/
|
|
void blk_steal_bios(struct bio_list *list, struct request *rq)
|
|
{
|
|
if (rq->bio) {
|
|
if (list->tail)
|
|
list->tail->bi_next = rq->bio;
|
|
else
|
|
list->head = rq->bio;
|
|
list->tail = rq->biotail;
|
|
|
|
rq->bio = NULL;
|
|
rq->biotail = NULL;
|
|
}
|
|
|
|
rq->__data_len = 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_steal_bios);
|
|
|
|
static size_t order_to_size(unsigned int order)
|
|
{
|
|
return (size_t)PAGE_SIZE << order;
|
|
}
|
|
|
|
/* called before freeing request pool in @tags */
|
|
static void blk_mq_clear_rq_mapping(struct blk_mq_tags *drv_tags,
|
|
struct blk_mq_tags *tags)
|
|
{
|
|
struct page *page;
|
|
unsigned long flags;
|
|
|
|
/* There is no need to clear a driver tags own mapping */
|
|
if (drv_tags == tags)
|
|
return;
|
|
|
|
list_for_each_entry(page, &tags->page_list, lru) {
|
|
unsigned long start = (unsigned long)page_address(page);
|
|
unsigned long end = start + order_to_size(page->private);
|
|
int i;
|
|
|
|
for (i = 0; i < drv_tags->nr_tags; i++) {
|
|
struct request *rq = drv_tags->rqs[i];
|
|
unsigned long rq_addr = (unsigned long)rq;
|
|
|
|
if (rq_addr >= start && rq_addr < end) {
|
|
WARN_ON_ONCE(req_ref_read(rq) != 0);
|
|
cmpxchg(&drv_tags->rqs[i], rq, NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Wait until all pending iteration is done.
|
|
*
|
|
* Request reference is cleared and it is guaranteed to be observed
|
|
* after the ->lock is released.
|
|
*/
|
|
spin_lock_irqsave(&drv_tags->lock, flags);
|
|
spin_unlock_irqrestore(&drv_tags->lock, flags);
|
|
}
|
|
|
|
void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
|
|
unsigned int hctx_idx)
|
|
{
|
|
struct blk_mq_tags *drv_tags;
|
|
struct page *page;
|
|
|
|
if (blk_mq_is_shared_tags(set->flags))
|
|
drv_tags = set->shared_tags;
|
|
else
|
|
drv_tags = set->tags[hctx_idx];
|
|
|
|
if (tags->static_rqs && set->ops->exit_request) {
|
|
int i;
|
|
|
|
for (i = 0; i < tags->nr_tags; i++) {
|
|
struct request *rq = tags->static_rqs[i];
|
|
|
|
if (!rq)
|
|
continue;
|
|
set->ops->exit_request(set, rq, hctx_idx);
|
|
tags->static_rqs[i] = NULL;
|
|
}
|
|
}
|
|
|
|
blk_mq_clear_rq_mapping(drv_tags, tags);
|
|
|
|
while (!list_empty(&tags->page_list)) {
|
|
page = list_first_entry(&tags->page_list, struct page, lru);
|
|
list_del_init(&page->lru);
|
|
/*
|
|
* Remove kmemleak object previously allocated in
|
|
* blk_mq_alloc_rqs().
|
|
*/
|
|
kmemleak_free(page_address(page));
|
|
__free_pages(page, page->private);
|
|
}
|
|
}
|
|
|
|
void blk_mq_free_rq_map(struct blk_mq_tags *tags)
|
|
{
|
|
kfree(tags->rqs);
|
|
tags->rqs = NULL;
|
|
kfree(tags->static_rqs);
|
|
tags->static_rqs = NULL;
|
|
|
|
blk_mq_free_tags(tags);
|
|
}
|
|
|
|
static struct blk_mq_tags *blk_mq_alloc_rq_map(struct blk_mq_tag_set *set,
|
|
unsigned int hctx_idx,
|
|
unsigned int nr_tags,
|
|
unsigned int reserved_tags)
|
|
{
|
|
struct blk_mq_tags *tags;
|
|
int node;
|
|
|
|
node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx);
|
|
if (node == NUMA_NO_NODE)
|
|
node = set->numa_node;
|
|
|
|
tags = blk_mq_init_tags(nr_tags, reserved_tags, node,
|
|
BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
|
|
if (!tags)
|
|
return NULL;
|
|
|
|
tags->rqs = kcalloc_node(nr_tags, sizeof(struct request *),
|
|
GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
|
|
node);
|
|
if (!tags->rqs) {
|
|
blk_mq_free_tags(tags);
|
|
return NULL;
|
|
}
|
|
|
|
tags->static_rqs = kcalloc_node(nr_tags, sizeof(struct request *),
|
|
GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY,
|
|
node);
|
|
if (!tags->static_rqs) {
|
|
kfree(tags->rqs);
|
|
blk_mq_free_tags(tags);
|
|
return NULL;
|
|
}
|
|
|
|
return tags;
|
|
}
|
|
|
|
static int blk_mq_init_request(struct blk_mq_tag_set *set, struct request *rq,
|
|
unsigned int hctx_idx, int node)
|
|
{
|
|
int ret;
|
|
|
|
if (set->ops->init_request) {
|
|
ret = set->ops->init_request(set, rq, hctx_idx, node);
|
|
if (ret)
|
|
return ret;
|
|
}
|
|
|
|
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
|
|
return 0;
|
|
}
|
|
|
|
static int blk_mq_alloc_rqs(struct blk_mq_tag_set *set,
|
|
struct blk_mq_tags *tags,
|
|
unsigned int hctx_idx, unsigned int depth)
|
|
{
|
|
unsigned int i, j, entries_per_page, max_order = 4;
|
|
size_t rq_size, left;
|
|
int node;
|
|
|
|
node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], hctx_idx);
|
|
if (node == NUMA_NO_NODE)
|
|
node = set->numa_node;
|
|
|
|
INIT_LIST_HEAD(&tags->page_list);
|
|
|
|
/*
|
|
* rq_size is the size of the request plus driver payload, rounded
|
|
* to the cacheline size
|
|
*/
|
|
rq_size = round_up(sizeof(struct request) + set->cmd_size,
|
|
cache_line_size());
|
|
left = rq_size * depth;
|
|
|
|
for (i = 0; i < depth; ) {
|
|
int this_order = max_order;
|
|
struct page *page;
|
|
int to_do;
|
|
void *p;
|
|
|
|
while (this_order && left < order_to_size(this_order - 1))
|
|
this_order--;
|
|
|
|
do {
|
|
page = alloc_pages_node(node,
|
|
GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
|
|
this_order);
|
|
if (page)
|
|
break;
|
|
if (!this_order--)
|
|
break;
|
|
if (order_to_size(this_order) < rq_size)
|
|
break;
|
|
} while (1);
|
|
|
|
if (!page)
|
|
goto fail;
|
|
|
|
page->private = this_order;
|
|
list_add_tail(&page->lru, &tags->page_list);
|
|
|
|
p = page_address(page);
|
|
/*
|
|
* Allow kmemleak to scan these pages as they contain pointers
|
|
* to additional allocations like via ops->init_request().
|
|
*/
|
|
kmemleak_alloc(p, order_to_size(this_order), 1, GFP_NOIO);
|
|
entries_per_page = order_to_size(this_order) / rq_size;
|
|
to_do = min(entries_per_page, depth - i);
|
|
left -= to_do * rq_size;
|
|
for (j = 0; j < to_do; j++) {
|
|
struct request *rq = p;
|
|
|
|
tags->static_rqs[i] = rq;
|
|
if (blk_mq_init_request(set, rq, hctx_idx, node)) {
|
|
tags->static_rqs[i] = NULL;
|
|
goto fail;
|
|
}
|
|
|
|
p += rq_size;
|
|
i++;
|
|
}
|
|
}
|
|
return 0;
|
|
|
|
fail:
|
|
blk_mq_free_rqs(set, tags, hctx_idx);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
struct rq_iter_data {
|
|
struct blk_mq_hw_ctx *hctx;
|
|
bool has_rq;
|
|
};
|
|
|
|
static bool blk_mq_has_request(struct request *rq, void *data, bool reserved)
|
|
{
|
|
struct rq_iter_data *iter_data = data;
|
|
|
|
if (rq->mq_hctx != iter_data->hctx)
|
|
return true;
|
|
iter_data->has_rq = true;
|
|
return false;
|
|
}
|
|
|
|
static bool blk_mq_hctx_has_requests(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
struct blk_mq_tags *tags = hctx->sched_tags ?
|
|
hctx->sched_tags : hctx->tags;
|
|
struct rq_iter_data data = {
|
|
.hctx = hctx,
|
|
};
|
|
|
|
blk_mq_all_tag_iter(tags, blk_mq_has_request, &data);
|
|
return data.has_rq;
|
|
}
|
|
|
|
static inline bool blk_mq_last_cpu_in_hctx(unsigned int cpu,
|
|
struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
if (cpumask_first_and(hctx->cpumask, cpu_online_mask) != cpu)
|
|
return false;
|
|
if (cpumask_next_and(cpu, hctx->cpumask, cpu_online_mask) < nr_cpu_ids)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static int blk_mq_hctx_notify_offline(unsigned int cpu, struct hlist_node *node)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
|
|
struct blk_mq_hw_ctx, cpuhp_online);
|
|
|
|
if (!cpumask_test_cpu(cpu, hctx->cpumask) ||
|
|
!blk_mq_last_cpu_in_hctx(cpu, hctx))
|
|
return 0;
|
|
|
|
/*
|
|
* Prevent new request from being allocated on the current hctx.
|
|
*
|
|
* The smp_mb__after_atomic() Pairs with the implied barrier in
|
|
* test_and_set_bit_lock in sbitmap_get(). Ensures the inactive flag is
|
|
* seen once we return from the tag allocator.
|
|
*/
|
|
set_bit(BLK_MQ_S_INACTIVE, &hctx->state);
|
|
smp_mb__after_atomic();
|
|
|
|
/*
|
|
* Try to grab a reference to the queue and wait for any outstanding
|
|
* requests. If we could not grab a reference the queue has been
|
|
* frozen and there are no requests.
|
|
*/
|
|
if (percpu_ref_tryget(&hctx->queue->q_usage_counter)) {
|
|
while (blk_mq_hctx_has_requests(hctx))
|
|
msleep(5);
|
|
percpu_ref_put(&hctx->queue->q_usage_counter);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blk_mq_hctx_notify_online(unsigned int cpu, struct hlist_node *node)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = hlist_entry_safe(node,
|
|
struct blk_mq_hw_ctx, cpuhp_online);
|
|
|
|
if (cpumask_test_cpu(cpu, hctx->cpumask))
|
|
clear_bit(BLK_MQ_S_INACTIVE, &hctx->state);
|
|
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_notify_dead(unsigned int cpu, struct hlist_node *node)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx;
|
|
LIST_HEAD(tmp);
|
|
enum hctx_type type;
|
|
|
|
hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
|
|
if (!cpumask_test_cpu(cpu, hctx->cpumask))
|
|
return 0;
|
|
|
|
ctx = __blk_mq_get_ctx(hctx->queue, cpu);
|
|
type = hctx->type;
|
|
|
|
spin_lock(&ctx->lock);
|
|
if (!list_empty(&ctx->rq_lists[type])) {
|
|
list_splice_init(&ctx->rq_lists[type], &tmp);
|
|
blk_mq_hctx_clear_pending(hctx, ctx);
|
|
}
|
|
spin_unlock(&ctx->lock);
|
|
|
|
if (list_empty(&tmp))
|
|
return 0;
|
|
|
|
spin_lock(&hctx->lock);
|
|
list_splice_tail_init(&tmp, &hctx->dispatch);
|
|
spin_unlock(&hctx->lock);
|
|
|
|
blk_mq_run_hw_queue(hctx, true);
|
|
return 0;
|
|
}
|
|
|
|
static void blk_mq_remove_cpuhp(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
if (!(hctx->flags & BLK_MQ_F_STACKING))
|
|
cpuhp_state_remove_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
|
|
&hctx->cpuhp_online);
|
|
cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD,
|
|
&hctx->cpuhp_dead);
|
|
}
|
|
|
|
/*
|
|
* Before freeing hw queue, clearing the flush request reference in
|
|
* tags->rqs[] for avoiding potential UAF.
|
|
*/
|
|
static void blk_mq_clear_flush_rq_mapping(struct blk_mq_tags *tags,
|
|
unsigned int queue_depth, struct request *flush_rq)
|
|
{
|
|
int i;
|
|
unsigned long flags;
|
|
|
|
/* The hw queue may not be mapped yet */
|
|
if (!tags)
|
|
return;
|
|
|
|
WARN_ON_ONCE(req_ref_read(flush_rq) != 0);
|
|
|
|
for (i = 0; i < queue_depth; i++)
|
|
cmpxchg(&tags->rqs[i], flush_rq, NULL);
|
|
|
|
/*
|
|
* Wait until all pending iteration is done.
|
|
*
|
|
* Request reference is cleared and it is guaranteed to be observed
|
|
* after the ->lock is released.
|
|
*/
|
|
spin_lock_irqsave(&tags->lock, flags);
|
|
spin_unlock_irqrestore(&tags->lock, flags);
|
|
}
|
|
|
|
/* hctx->ctxs will be freed in queue's release handler */
|
|
static void blk_mq_exit_hctx(struct request_queue *q,
|
|
struct blk_mq_tag_set *set,
|
|
struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
|
|
{
|
|
struct request *flush_rq = hctx->fq->flush_rq;
|
|
|
|
if (blk_mq_hw_queue_mapped(hctx))
|
|
blk_mq_tag_idle(hctx);
|
|
|
|
blk_mq_clear_flush_rq_mapping(set->tags[hctx_idx],
|
|
set->queue_depth, flush_rq);
|
|
if (set->ops->exit_request)
|
|
set->ops->exit_request(set, flush_rq, hctx_idx);
|
|
|
|
if (set->ops->exit_hctx)
|
|
set->ops->exit_hctx(hctx, hctx_idx);
|
|
|
|
blk_mq_remove_cpuhp(hctx);
|
|
|
|
spin_lock(&q->unused_hctx_lock);
|
|
list_add(&hctx->hctx_list, &q->unused_hctx_list);
|
|
spin_unlock(&q->unused_hctx_lock);
|
|
}
|
|
|
|
static void blk_mq_exit_hw_queues(struct request_queue *q,
|
|
struct blk_mq_tag_set *set, int nr_queue)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
unsigned int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (i == nr_queue)
|
|
break;
|
|
blk_mq_debugfs_unregister_hctx(hctx);
|
|
blk_mq_exit_hctx(q, set, hctx, i);
|
|
}
|
|
}
|
|
|
|
static int blk_mq_init_hctx(struct request_queue *q,
|
|
struct blk_mq_tag_set *set,
|
|
struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
|
|
{
|
|
hctx->queue_num = hctx_idx;
|
|
|
|
if (!(hctx->flags & BLK_MQ_F_STACKING))
|
|
cpuhp_state_add_instance_nocalls(CPUHP_AP_BLK_MQ_ONLINE,
|
|
&hctx->cpuhp_online);
|
|
cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
|
|
|
|
hctx->tags = set->tags[hctx_idx];
|
|
|
|
if (set->ops->init_hctx &&
|
|
set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
|
|
goto unregister_cpu_notifier;
|
|
|
|
if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx,
|
|
hctx->numa_node))
|
|
goto exit_hctx;
|
|
return 0;
|
|
|
|
exit_hctx:
|
|
if (set->ops->exit_hctx)
|
|
set->ops->exit_hctx(hctx, hctx_idx);
|
|
unregister_cpu_notifier:
|
|
blk_mq_remove_cpuhp(hctx);
|
|
return -1;
|
|
}
|
|
|
|
static struct blk_mq_hw_ctx *
|
|
blk_mq_alloc_hctx(struct request_queue *q, struct blk_mq_tag_set *set,
|
|
int node)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
gfp_t gfp = GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY;
|
|
|
|
hctx = kzalloc_node(sizeof(struct blk_mq_hw_ctx), gfp, node);
|
|
if (!hctx)
|
|
goto fail_alloc_hctx;
|
|
|
|
if (!zalloc_cpumask_var_node(&hctx->cpumask, gfp, node))
|
|
goto free_hctx;
|
|
|
|
atomic_set(&hctx->nr_active, 0);
|
|
if (node == NUMA_NO_NODE)
|
|
node = set->numa_node;
|
|
hctx->numa_node = node;
|
|
|
|
INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
|
|
spin_lock_init(&hctx->lock);
|
|
INIT_LIST_HEAD(&hctx->dispatch);
|
|
hctx->queue = q;
|
|
hctx->flags = set->flags & ~BLK_MQ_F_TAG_QUEUE_SHARED;
|
|
|
|
INIT_LIST_HEAD(&hctx->hctx_list);
|
|
|
|
/*
|
|
* Allocate space for all possible cpus to avoid allocation at
|
|
* runtime
|
|
*/
|
|
hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *),
|
|
gfp, node);
|
|
if (!hctx->ctxs)
|
|
goto free_cpumask;
|
|
|
|
if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8),
|
|
gfp, node, false, false))
|
|
goto free_ctxs;
|
|
hctx->nr_ctx = 0;
|
|
|
|
spin_lock_init(&hctx->dispatch_wait_lock);
|
|
init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake);
|
|
INIT_LIST_HEAD(&hctx->dispatch_wait.entry);
|
|
|
|
hctx->fq = blk_alloc_flush_queue(hctx->numa_node, set->cmd_size, gfp);
|
|
if (!hctx->fq)
|
|
goto free_bitmap;
|
|
|
|
blk_mq_hctx_kobj_init(hctx);
|
|
|
|
return hctx;
|
|
|
|
free_bitmap:
|
|
sbitmap_free(&hctx->ctx_map);
|
|
free_ctxs:
|
|
kfree(hctx->ctxs);
|
|
free_cpumask:
|
|
free_cpumask_var(hctx->cpumask);
|
|
free_hctx:
|
|
kfree(hctx);
|
|
fail_alloc_hctx:
|
|
return NULL;
|
|
}
|
|
|
|
static void blk_mq_init_cpu_queues(struct request_queue *q,
|
|
unsigned int nr_hw_queues)
|
|
{
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
unsigned int i, j;
|
|
|
|
for_each_possible_cpu(i) {
|
|
struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int k;
|
|
|
|
__ctx->cpu = i;
|
|
spin_lock_init(&__ctx->lock);
|
|
for (k = HCTX_TYPE_DEFAULT; k < HCTX_MAX_TYPES; k++)
|
|
INIT_LIST_HEAD(&__ctx->rq_lists[k]);
|
|
|
|
__ctx->queue = q;
|
|
|
|
/*
|
|
* Set local node, IFF we have more than one hw queue. If
|
|
* not, we remain on the home node of the device
|
|
*/
|
|
for (j = 0; j < set->nr_maps; j++) {
|
|
hctx = blk_mq_map_queue_type(q, j, i);
|
|
if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
|
|
hctx->numa_node = cpu_to_node(i);
|
|
}
|
|
}
|
|
}
|
|
|
|
struct blk_mq_tags *blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
|
|
unsigned int hctx_idx,
|
|
unsigned int depth)
|
|
{
|
|
struct blk_mq_tags *tags;
|
|
int ret;
|
|
|
|
tags = blk_mq_alloc_rq_map(set, hctx_idx, depth, set->reserved_tags);
|
|
if (!tags)
|
|
return NULL;
|
|
|
|
ret = blk_mq_alloc_rqs(set, tags, hctx_idx, depth);
|
|
if (ret) {
|
|
blk_mq_free_rq_map(tags);
|
|
return NULL;
|
|
}
|
|
|
|
return tags;
|
|
}
|
|
|
|
static bool __blk_mq_alloc_map_and_rqs(struct blk_mq_tag_set *set,
|
|
int hctx_idx)
|
|
{
|
|
if (blk_mq_is_shared_tags(set->flags)) {
|
|
set->tags[hctx_idx] = set->shared_tags;
|
|
|
|
return true;
|
|
}
|
|
|
|
set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs(set, hctx_idx,
|
|
set->queue_depth);
|
|
|
|
return set->tags[hctx_idx];
|
|
}
|
|
|
|
void blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
|
|
struct blk_mq_tags *tags,
|
|
unsigned int hctx_idx)
|
|
{
|
|
if (tags) {
|
|
blk_mq_free_rqs(set, tags, hctx_idx);
|
|
blk_mq_free_rq_map(tags);
|
|
}
|
|
}
|
|
|
|
static void __blk_mq_free_map_and_rqs(struct blk_mq_tag_set *set,
|
|
unsigned int hctx_idx)
|
|
{
|
|
if (!blk_mq_is_shared_tags(set->flags))
|
|
blk_mq_free_map_and_rqs(set, set->tags[hctx_idx], hctx_idx);
|
|
|
|
set->tags[hctx_idx] = NULL;
|
|
}
|
|
|
|
static void blk_mq_map_swqueue(struct request_queue *q)
|
|
{
|
|
unsigned int i, j, hctx_idx;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx;
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
cpumask_clear(hctx->cpumask);
|
|
hctx->nr_ctx = 0;
|
|
hctx->dispatch_from = NULL;
|
|
}
|
|
|
|
/*
|
|
* Map software to hardware queues.
|
|
*
|
|
* If the cpu isn't present, the cpu is mapped to first hctx.
|
|
*/
|
|
for_each_possible_cpu(i) {
|
|
|
|
ctx = per_cpu_ptr(q->queue_ctx, i);
|
|
for (j = 0; j < set->nr_maps; j++) {
|
|
if (!set->map[j].nr_queues) {
|
|
ctx->hctxs[j] = blk_mq_map_queue_type(q,
|
|
HCTX_TYPE_DEFAULT, i);
|
|
continue;
|
|
}
|
|
hctx_idx = set->map[j].mq_map[i];
|
|
/* unmapped hw queue can be remapped after CPU topo changed */
|
|
if (!set->tags[hctx_idx] &&
|
|
!__blk_mq_alloc_map_and_rqs(set, hctx_idx)) {
|
|
/*
|
|
* If tags initialization fail for some hctx,
|
|
* that hctx won't be brought online. In this
|
|
* case, remap the current ctx to hctx[0] which
|
|
* is guaranteed to always have tags allocated
|
|
*/
|
|
set->map[j].mq_map[i] = 0;
|
|
}
|
|
|
|
hctx = blk_mq_map_queue_type(q, j, i);
|
|
ctx->hctxs[j] = hctx;
|
|
/*
|
|
* If the CPU is already set in the mask, then we've
|
|
* mapped this one already. This can happen if
|
|
* devices share queues across queue maps.
|
|
*/
|
|
if (cpumask_test_cpu(i, hctx->cpumask))
|
|
continue;
|
|
|
|
cpumask_set_cpu(i, hctx->cpumask);
|
|
hctx->type = j;
|
|
ctx->index_hw[hctx->type] = hctx->nr_ctx;
|
|
hctx->ctxs[hctx->nr_ctx++] = ctx;
|
|
|
|
/*
|
|
* If the nr_ctx type overflows, we have exceeded the
|
|
* amount of sw queues we can support.
|
|
*/
|
|
BUG_ON(!hctx->nr_ctx);
|
|
}
|
|
|
|
for (; j < HCTX_MAX_TYPES; j++)
|
|
ctx->hctxs[j] = blk_mq_map_queue_type(q,
|
|
HCTX_TYPE_DEFAULT, i);
|
|
}
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
/*
|
|
* If no software queues are mapped to this hardware queue,
|
|
* disable it and free the request entries.
|
|
*/
|
|
if (!hctx->nr_ctx) {
|
|
/* Never unmap queue 0. We need it as a
|
|
* fallback in case of a new remap fails
|
|
* allocation
|
|
*/
|
|
if (i)
|
|
__blk_mq_free_map_and_rqs(set, i);
|
|
|
|
hctx->tags = NULL;
|
|
continue;
|
|
}
|
|
|
|
hctx->tags = set->tags[i];
|
|
WARN_ON(!hctx->tags);
|
|
|
|
/*
|
|
* Set the map size to the number of mapped software queues.
|
|
* This is more accurate and more efficient than looping
|
|
* over all possibly mapped software queues.
|
|
*/
|
|
sbitmap_resize(&hctx->ctx_map, hctx->nr_ctx);
|
|
|
|
/*
|
|
* Initialize batch roundrobin counts
|
|
*/
|
|
hctx->next_cpu = blk_mq_first_mapped_cpu(hctx);
|
|
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Caller needs to ensure that we're either frozen/quiesced, or that
|
|
* the queue isn't live yet.
|
|
*/
|
|
static void queue_set_hctx_shared(struct request_queue *q, bool shared)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (shared) {
|
|
hctx->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
|
|
} else {
|
|
blk_mq_tag_idle(hctx);
|
|
hctx->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void blk_mq_update_tag_set_shared(struct blk_mq_tag_set *set,
|
|
bool shared)
|
|
{
|
|
struct request_queue *q;
|
|
|
|
lockdep_assert_held(&set->tag_list_lock);
|
|
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list) {
|
|
blk_mq_freeze_queue(q);
|
|
queue_set_hctx_shared(q, shared);
|
|
blk_mq_unfreeze_queue(q);
|
|
}
|
|
}
|
|
|
|
static void blk_mq_del_queue_tag_set(struct request_queue *q)
|
|
{
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
mutex_lock(&set->tag_list_lock);
|
|
list_del(&q->tag_set_list);
|
|
if (list_is_singular(&set->tag_list)) {
|
|
/* just transitioned to unshared */
|
|
set->flags &= ~BLK_MQ_F_TAG_QUEUE_SHARED;
|
|
/* update existing queue */
|
|
blk_mq_update_tag_set_shared(set, false);
|
|
}
|
|
mutex_unlock(&set->tag_list_lock);
|
|
INIT_LIST_HEAD(&q->tag_set_list);
|
|
}
|
|
|
|
static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
|
|
struct request_queue *q)
|
|
{
|
|
mutex_lock(&set->tag_list_lock);
|
|
|
|
/*
|
|
* Check to see if we're transitioning to shared (from 1 to 2 queues).
|
|
*/
|
|
if (!list_empty(&set->tag_list) &&
|
|
!(set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)) {
|
|
set->flags |= BLK_MQ_F_TAG_QUEUE_SHARED;
|
|
/* update existing queue */
|
|
blk_mq_update_tag_set_shared(set, true);
|
|
}
|
|
if (set->flags & BLK_MQ_F_TAG_QUEUE_SHARED)
|
|
queue_set_hctx_shared(q, true);
|
|
list_add_tail(&q->tag_set_list, &set->tag_list);
|
|
|
|
mutex_unlock(&set->tag_list_lock);
|
|
}
|
|
|
|
/* All allocations will be freed in release handler of q->mq_kobj */
|
|
static int blk_mq_alloc_ctxs(struct request_queue *q)
|
|
{
|
|
struct blk_mq_ctxs *ctxs;
|
|
int cpu;
|
|
|
|
ctxs = kzalloc(sizeof(*ctxs), GFP_KERNEL);
|
|
if (!ctxs)
|
|
return -ENOMEM;
|
|
|
|
ctxs->queue_ctx = alloc_percpu(struct blk_mq_ctx);
|
|
if (!ctxs->queue_ctx)
|
|
goto fail;
|
|
|
|
for_each_possible_cpu(cpu) {
|
|
struct blk_mq_ctx *ctx = per_cpu_ptr(ctxs->queue_ctx, cpu);
|
|
ctx->ctxs = ctxs;
|
|
}
|
|
|
|
q->mq_kobj = &ctxs->kobj;
|
|
q->queue_ctx = ctxs->queue_ctx;
|
|
|
|
return 0;
|
|
fail:
|
|
kfree(ctxs);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* It is the actual release handler for mq, but we do it from
|
|
* request queue's release handler for avoiding use-after-free
|
|
* and headache because q->mq_kobj shouldn't have been introduced,
|
|
* but we can't group ctx/kctx kobj without it.
|
|
*/
|
|
void blk_mq_release(struct request_queue *q)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx, *next;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
WARN_ON_ONCE(hctx && list_empty(&hctx->hctx_list));
|
|
|
|
/* all hctx are in .unused_hctx_list now */
|
|
list_for_each_entry_safe(hctx, next, &q->unused_hctx_list, hctx_list) {
|
|
list_del_init(&hctx->hctx_list);
|
|
kobject_put(&hctx->kobj);
|
|
}
|
|
|
|
kfree(q->queue_hw_ctx);
|
|
|
|
/*
|
|
* release .mq_kobj and sw queue's kobject now because
|
|
* both share lifetime with request queue.
|
|
*/
|
|
blk_mq_sysfs_deinit(q);
|
|
}
|
|
|
|
static struct request_queue *blk_mq_init_queue_data(struct blk_mq_tag_set *set,
|
|
void *queuedata)
|
|
{
|
|
struct request_queue *q;
|
|
int ret;
|
|
|
|
q = blk_alloc_queue(set->numa_node, set->flags & BLK_MQ_F_BLOCKING);
|
|
if (!q)
|
|
return ERR_PTR(-ENOMEM);
|
|
q->queuedata = queuedata;
|
|
ret = blk_mq_init_allocated_queue(set, q);
|
|
if (ret) {
|
|
blk_cleanup_queue(q);
|
|
return ERR_PTR(ret);
|
|
}
|
|
return q;
|
|
}
|
|
|
|
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
|
|
{
|
|
return blk_mq_init_queue_data(set, NULL);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_init_queue);
|
|
|
|
struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata,
|
|
struct lock_class_key *lkclass)
|
|
{
|
|
struct request_queue *q;
|
|
struct gendisk *disk;
|
|
|
|
q = blk_mq_init_queue_data(set, queuedata);
|
|
if (IS_ERR(q))
|
|
return ERR_CAST(q);
|
|
|
|
disk = __alloc_disk_node(q, set->numa_node, lkclass);
|
|
if (!disk) {
|
|
blk_cleanup_queue(q);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
return disk;
|
|
}
|
|
EXPORT_SYMBOL(__blk_mq_alloc_disk);
|
|
|
|
static struct blk_mq_hw_ctx *blk_mq_alloc_and_init_hctx(
|
|
struct blk_mq_tag_set *set, struct request_queue *q,
|
|
int hctx_idx, int node)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = NULL, *tmp;
|
|
|
|
/* reuse dead hctx first */
|
|
spin_lock(&q->unused_hctx_lock);
|
|
list_for_each_entry(tmp, &q->unused_hctx_list, hctx_list) {
|
|
if (tmp->numa_node == node) {
|
|
hctx = tmp;
|
|
break;
|
|
}
|
|
}
|
|
if (hctx)
|
|
list_del_init(&hctx->hctx_list);
|
|
spin_unlock(&q->unused_hctx_lock);
|
|
|
|
if (!hctx)
|
|
hctx = blk_mq_alloc_hctx(q, set, node);
|
|
if (!hctx)
|
|
goto fail;
|
|
|
|
if (blk_mq_init_hctx(q, set, hctx, hctx_idx))
|
|
goto free_hctx;
|
|
|
|
return hctx;
|
|
|
|
free_hctx:
|
|
kobject_put(&hctx->kobj);
|
|
fail:
|
|
return NULL;
|
|
}
|
|
|
|
static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
|
|
struct request_queue *q)
|
|
{
|
|
int i, j, end;
|
|
struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
|
|
|
|
if (q->nr_hw_queues < set->nr_hw_queues) {
|
|
struct blk_mq_hw_ctx **new_hctxs;
|
|
|
|
new_hctxs = kcalloc_node(set->nr_hw_queues,
|
|
sizeof(*new_hctxs), GFP_KERNEL,
|
|
set->numa_node);
|
|
if (!new_hctxs)
|
|
return;
|
|
if (hctxs)
|
|
memcpy(new_hctxs, hctxs, q->nr_hw_queues *
|
|
sizeof(*hctxs));
|
|
q->queue_hw_ctx = new_hctxs;
|
|
kfree(hctxs);
|
|
hctxs = new_hctxs;
|
|
}
|
|
|
|
/* protect against switching io scheduler */
|
|
mutex_lock(&q->sysfs_lock);
|
|
for (i = 0; i < set->nr_hw_queues; i++) {
|
|
int node;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
|
|
node = blk_mq_hw_queue_to_node(&set->map[HCTX_TYPE_DEFAULT], i);
|
|
/*
|
|
* If the hw queue has been mapped to another numa node,
|
|
* we need to realloc the hctx. If allocation fails, fallback
|
|
* to use the previous one.
|
|
*/
|
|
if (hctxs[i] && (hctxs[i]->numa_node == node))
|
|
continue;
|
|
|
|
hctx = blk_mq_alloc_and_init_hctx(set, q, i, node);
|
|
if (hctx) {
|
|
if (hctxs[i])
|
|
blk_mq_exit_hctx(q, set, hctxs[i], i);
|
|
hctxs[i] = hctx;
|
|
} else {
|
|
if (hctxs[i])
|
|
pr_warn("Allocate new hctx on node %d fails,\
|
|
fallback to previous one on node %d\n",
|
|
node, hctxs[i]->numa_node);
|
|
else
|
|
break;
|
|
}
|
|
}
|
|
/*
|
|
* Increasing nr_hw_queues fails. Free the newly allocated
|
|
* hctxs and keep the previous q->nr_hw_queues.
|
|
*/
|
|
if (i != set->nr_hw_queues) {
|
|
j = q->nr_hw_queues;
|
|
end = i;
|
|
} else {
|
|
j = i;
|
|
end = q->nr_hw_queues;
|
|
q->nr_hw_queues = set->nr_hw_queues;
|
|
}
|
|
|
|
for (; j < end; j++) {
|
|
struct blk_mq_hw_ctx *hctx = hctxs[j];
|
|
|
|
if (hctx) {
|
|
blk_mq_exit_hctx(q, set, hctx, j);
|
|
hctxs[j] = NULL;
|
|
}
|
|
}
|
|
mutex_unlock(&q->sysfs_lock);
|
|
}
|
|
|
|
int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
|
|
struct request_queue *q)
|
|
{
|
|
WARN_ON_ONCE(blk_queue_has_srcu(q) !=
|
|
!!(set->flags & BLK_MQ_F_BLOCKING));
|
|
|
|
/* mark the queue as mq asap */
|
|
q->mq_ops = set->ops;
|
|
|
|
q->poll_cb = blk_stat_alloc_callback(blk_mq_poll_stats_fn,
|
|
blk_mq_poll_stats_bkt,
|
|
BLK_MQ_POLL_STATS_BKTS, q);
|
|
if (!q->poll_cb)
|
|
goto err_exit;
|
|
|
|
if (blk_mq_alloc_ctxs(q))
|
|
goto err_poll;
|
|
|
|
/* init q->mq_kobj and sw queues' kobjects */
|
|
blk_mq_sysfs_init(q);
|
|
|
|
INIT_LIST_HEAD(&q->unused_hctx_list);
|
|
spin_lock_init(&q->unused_hctx_lock);
|
|
|
|
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->tag_set = set;
|
|
|
|
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
|
|
if (set->nr_maps > HCTX_TYPE_POLL &&
|
|
set->map[HCTX_TYPE_POLL].nr_queues)
|
|
blk_queue_flag_set(QUEUE_FLAG_POLL, q);
|
|
|
|
INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
|
|
INIT_LIST_HEAD(&q->requeue_list);
|
|
spin_lock_init(&q->requeue_lock);
|
|
|
|
q->nr_requests = set->queue_depth;
|
|
|
|
/*
|
|
* Default to classic polling
|
|
*/
|
|
q->poll_nsec = BLK_MQ_POLL_CLASSIC;
|
|
|
|
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
|
|
blk_mq_add_queue_tag_set(set, q);
|
|
blk_mq_map_swqueue(q);
|
|
return 0;
|
|
|
|
err_hctxs:
|
|
kfree(q->queue_hw_ctx);
|
|
q->nr_hw_queues = 0;
|
|
blk_mq_sysfs_deinit(q);
|
|
err_poll:
|
|
blk_stat_free_callback(q->poll_cb);
|
|
q->poll_cb = NULL;
|
|
err_exit:
|
|
q->mq_ops = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_init_allocated_queue);
|
|
|
|
/* tags can _not_ be used after returning from blk_mq_exit_queue */
|
|
void blk_mq_exit_queue(struct request_queue *q)
|
|
{
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
/* Checks hctx->flags & BLK_MQ_F_TAG_QUEUE_SHARED. */
|
|
blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
|
|
/* May clear BLK_MQ_F_TAG_QUEUE_SHARED in hctx->flags. */
|
|
blk_mq_del_queue_tag_set(q);
|
|
}
|
|
|
|
static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
|
|
{
|
|
int i;
|
|
|
|
if (blk_mq_is_shared_tags(set->flags)) {
|
|
set->shared_tags = blk_mq_alloc_map_and_rqs(set,
|
|
BLK_MQ_NO_HCTX_IDX,
|
|
set->queue_depth);
|
|
if (!set->shared_tags)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
for (i = 0; i < set->nr_hw_queues; i++) {
|
|
if (!__blk_mq_alloc_map_and_rqs(set, i))
|
|
goto out_unwind;
|
|
cond_resched();
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_unwind:
|
|
while (--i >= 0)
|
|
__blk_mq_free_map_and_rqs(set, i);
|
|
|
|
if (blk_mq_is_shared_tags(set->flags)) {
|
|
blk_mq_free_map_and_rqs(set, set->shared_tags,
|
|
BLK_MQ_NO_HCTX_IDX);
|
|
}
|
|
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/*
|
|
* Allocate the request maps associated with this tag_set. Note that this
|
|
* may reduce the depth asked for, if memory is tight. set->queue_depth
|
|
* will be updated to reflect the allocated depth.
|
|
*/
|
|
static int blk_mq_alloc_set_map_and_rqs(struct blk_mq_tag_set *set)
|
|
{
|
|
unsigned int depth;
|
|
int err;
|
|
|
|
depth = set->queue_depth;
|
|
do {
|
|
err = __blk_mq_alloc_rq_maps(set);
|
|
if (!err)
|
|
break;
|
|
|
|
set->queue_depth >>= 1;
|
|
if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
|
|
err = -ENOMEM;
|
|
break;
|
|
}
|
|
} while (set->queue_depth);
|
|
|
|
if (!set->queue_depth || err) {
|
|
pr_err("blk-mq: failed to allocate request map\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
if (depth != set->queue_depth)
|
|
pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
|
|
depth, set->queue_depth);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blk_mq_update_queue_map(struct blk_mq_tag_set *set)
|
|
{
|
|
/*
|
|
* blk_mq_map_queues() and multiple .map_queues() implementations
|
|
* expect that set->map[HCTX_TYPE_DEFAULT].nr_queues is set to the
|
|
* number of hardware queues.
|
|
*/
|
|
if (set->nr_maps == 1)
|
|
set->map[HCTX_TYPE_DEFAULT].nr_queues = set->nr_hw_queues;
|
|
|
|
if (set->ops->map_queues && !is_kdump_kernel()) {
|
|
int i;
|
|
|
|
/*
|
|
* transport .map_queues is usually done in the following
|
|
* way:
|
|
*
|
|
* for (queue = 0; queue < set->nr_hw_queues; queue++) {
|
|
* mask = get_cpu_mask(queue)
|
|
* for_each_cpu(cpu, mask)
|
|
* set->map[x].mq_map[cpu] = queue;
|
|
* }
|
|
*
|
|
* When we need to remap, the table has to be cleared for
|
|
* killing stale mapping since one CPU may not be mapped
|
|
* to any hw queue.
|
|
*/
|
|
for (i = 0; i < set->nr_maps; i++)
|
|
blk_mq_clear_mq_map(&set->map[i]);
|
|
|
|
return set->ops->map_queues(set);
|
|
} else {
|
|
BUG_ON(set->nr_maps > 1);
|
|
return blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
|
|
}
|
|
}
|
|
|
|
static int blk_mq_realloc_tag_set_tags(struct blk_mq_tag_set *set,
|
|
int cur_nr_hw_queues, int new_nr_hw_queues)
|
|
{
|
|
struct blk_mq_tags **new_tags;
|
|
|
|
if (cur_nr_hw_queues >= new_nr_hw_queues)
|
|
return 0;
|
|
|
|
new_tags = kcalloc_node(new_nr_hw_queues, sizeof(struct blk_mq_tags *),
|
|
GFP_KERNEL, set->numa_node);
|
|
if (!new_tags)
|
|
return -ENOMEM;
|
|
|
|
if (set->tags)
|
|
memcpy(new_tags, set->tags, cur_nr_hw_queues *
|
|
sizeof(*set->tags));
|
|
kfree(set->tags);
|
|
set->tags = new_tags;
|
|
set->nr_hw_queues = new_nr_hw_queues;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blk_mq_alloc_tag_set_tags(struct blk_mq_tag_set *set,
|
|
int new_nr_hw_queues)
|
|
{
|
|
return blk_mq_realloc_tag_set_tags(set, 0, new_nr_hw_queues);
|
|
}
|
|
|
|
/*
|
|
* Alloc a tag set to be associated with one or more request queues.
|
|
* May fail with EINVAL for various error conditions. May adjust the
|
|
* requested depth down, if it's too large. In that case, the set
|
|
* value will be stored in set->queue_depth.
|
|
*/
|
|
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
|
|
{
|
|
int i, ret;
|
|
|
|
BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
|
|
|
|
if (!set->nr_hw_queues)
|
|
return -EINVAL;
|
|
if (!set->queue_depth)
|
|
return -EINVAL;
|
|
if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
|
|
return -EINVAL;
|
|
|
|
if (!set->ops->queue_rq)
|
|
return -EINVAL;
|
|
|
|
if (!set->ops->get_budget ^ !set->ops->put_budget)
|
|
return -EINVAL;
|
|
|
|
if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
|
|
pr_info("blk-mq: reduced tag depth to %u\n",
|
|
BLK_MQ_MAX_DEPTH);
|
|
set->queue_depth = BLK_MQ_MAX_DEPTH;
|
|
}
|
|
|
|
if (!set->nr_maps)
|
|
set->nr_maps = 1;
|
|
else if (set->nr_maps > HCTX_MAX_TYPES)
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* If a crashdump is active, then we are potentially in a very
|
|
* memory constrained environment. Limit us to 1 queue and
|
|
* 64 tags to prevent using too much memory.
|
|
*/
|
|
if (is_kdump_kernel()) {
|
|
set->nr_hw_queues = 1;
|
|
set->nr_maps = 1;
|
|
set->queue_depth = min(64U, set->queue_depth);
|
|
}
|
|
/*
|
|
* There is no use for more h/w queues than cpus if we just have
|
|
* a single map
|
|
*/
|
|
if (set->nr_maps == 1 && set->nr_hw_queues > nr_cpu_ids)
|
|
set->nr_hw_queues = nr_cpu_ids;
|
|
|
|
if (blk_mq_alloc_tag_set_tags(set, set->nr_hw_queues) < 0)
|
|
return -ENOMEM;
|
|
|
|
ret = -ENOMEM;
|
|
for (i = 0; i < set->nr_maps; i++) {
|
|
set->map[i].mq_map = kcalloc_node(nr_cpu_ids,
|
|
sizeof(set->map[i].mq_map[0]),
|
|
GFP_KERNEL, set->numa_node);
|
|
if (!set->map[i].mq_map)
|
|
goto out_free_mq_map;
|
|
set->map[i].nr_queues = is_kdump_kernel() ? 1 : set->nr_hw_queues;
|
|
}
|
|
|
|
ret = blk_mq_update_queue_map(set);
|
|
if (ret)
|
|
goto out_free_mq_map;
|
|
|
|
ret = blk_mq_alloc_set_map_and_rqs(set);
|
|
if (ret)
|
|
goto out_free_mq_map;
|
|
|
|
mutex_init(&set->tag_list_lock);
|
|
INIT_LIST_HEAD(&set->tag_list);
|
|
|
|
return 0;
|
|
|
|
out_free_mq_map:
|
|
for (i = 0; i < set->nr_maps; i++) {
|
|
kfree(set->map[i].mq_map);
|
|
set->map[i].mq_map = NULL;
|
|
}
|
|
kfree(set->tags);
|
|
set->tags = NULL;
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_alloc_tag_set);
|
|
|
|
/* allocate and initialize a tagset for a simple single-queue device */
|
|
int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set,
|
|
const struct blk_mq_ops *ops, unsigned int queue_depth,
|
|
unsigned int set_flags)
|
|
{
|
|
memset(set, 0, sizeof(*set));
|
|
set->ops = ops;
|
|
set->nr_hw_queues = 1;
|
|
set->nr_maps = 1;
|
|
set->queue_depth = queue_depth;
|
|
set->numa_node = NUMA_NO_NODE;
|
|
set->flags = set_flags;
|
|
return blk_mq_alloc_tag_set(set);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_alloc_sq_tag_set);
|
|
|
|
void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
|
|
{
|
|
int i, j;
|
|
|
|
for (i = 0; i < set->nr_hw_queues; i++)
|
|
__blk_mq_free_map_and_rqs(set, i);
|
|
|
|
if (blk_mq_is_shared_tags(set->flags)) {
|
|
blk_mq_free_map_and_rqs(set, set->shared_tags,
|
|
BLK_MQ_NO_HCTX_IDX);
|
|
}
|
|
|
|
for (j = 0; j < set->nr_maps; j++) {
|
|
kfree(set->map[j].mq_map);
|
|
set->map[j].mq_map = NULL;
|
|
}
|
|
|
|
kfree(set->tags);
|
|
set->tags = NULL;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_free_tag_set);
|
|
|
|
int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
|
|
{
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i, ret;
|
|
|
|
if (!set)
|
|
return -EINVAL;
|
|
|
|
if (q->nr_requests == nr)
|
|
return 0;
|
|
|
|
blk_mq_freeze_queue(q);
|
|
blk_mq_quiesce_queue(q);
|
|
|
|
ret = 0;
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (!hctx->tags)
|
|
continue;
|
|
/*
|
|
* If we're using an MQ scheduler, just update the scheduler
|
|
* queue depth. This is similar to what the old code would do.
|
|
*/
|
|
if (hctx->sched_tags) {
|
|
ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
|
|
nr, true);
|
|
} else {
|
|
ret = blk_mq_tag_update_depth(hctx, &hctx->tags, nr,
|
|
false);
|
|
}
|
|
if (ret)
|
|
break;
|
|
if (q->elevator && q->elevator->type->ops.depth_updated)
|
|
q->elevator->type->ops.depth_updated(hctx);
|
|
}
|
|
if (!ret) {
|
|
q->nr_requests = nr;
|
|
if (blk_mq_is_shared_tags(set->flags)) {
|
|
if (q->elevator)
|
|
blk_mq_tag_update_sched_shared_tags(q);
|
|
else
|
|
blk_mq_tag_resize_shared_tags(set, nr);
|
|
}
|
|
}
|
|
|
|
blk_mq_unquiesce_queue(q);
|
|
blk_mq_unfreeze_queue(q);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* request_queue and elevator_type pair.
|
|
* It is just used by __blk_mq_update_nr_hw_queues to cache
|
|
* the elevator_type associated with a request_queue.
|
|
*/
|
|
struct blk_mq_qe_pair {
|
|
struct list_head node;
|
|
struct request_queue *q;
|
|
struct elevator_type *type;
|
|
};
|
|
|
|
/*
|
|
* Cache the elevator_type in qe pair list and switch the
|
|
* io scheduler to 'none'
|
|
*/
|
|
static bool blk_mq_elv_switch_none(struct list_head *head,
|
|
struct request_queue *q)
|
|
{
|
|
struct blk_mq_qe_pair *qe;
|
|
|
|
if (!q->elevator)
|
|
return true;
|
|
|
|
qe = kmalloc(sizeof(*qe), GFP_NOIO | __GFP_NOWARN | __GFP_NORETRY);
|
|
if (!qe)
|
|
return false;
|
|
|
|
INIT_LIST_HEAD(&qe->node);
|
|
qe->q = q;
|
|
qe->type = q->elevator->type;
|
|
list_add(&qe->node, head);
|
|
|
|
mutex_lock(&q->sysfs_lock);
|
|
/*
|
|
* After elevator_switch_mq, the previous elevator_queue will be
|
|
* released by elevator_release. The reference of the io scheduler
|
|
* module get by elevator_get will also be put. So we need to get
|
|
* a reference of the io scheduler module here to prevent it to be
|
|
* removed.
|
|
*/
|
|
__module_get(qe->type->elevator_owner);
|
|
elevator_switch_mq(q, NULL);
|
|
mutex_unlock(&q->sysfs_lock);
|
|
|
|
return true;
|
|
}
|
|
|
|
static void blk_mq_elv_switch_back(struct list_head *head,
|
|
struct request_queue *q)
|
|
{
|
|
struct blk_mq_qe_pair *qe;
|
|
struct elevator_type *t = NULL;
|
|
|
|
list_for_each_entry(qe, head, node)
|
|
if (qe->q == q) {
|
|
t = qe->type;
|
|
break;
|
|
}
|
|
|
|
if (!t)
|
|
return;
|
|
|
|
list_del(&qe->node);
|
|
kfree(qe);
|
|
|
|
mutex_lock(&q->sysfs_lock);
|
|
elevator_switch_mq(q, t);
|
|
mutex_unlock(&q->sysfs_lock);
|
|
}
|
|
|
|
static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
|
|
int nr_hw_queues)
|
|
{
|
|
struct request_queue *q;
|
|
LIST_HEAD(head);
|
|
int prev_nr_hw_queues;
|
|
|
|
lockdep_assert_held(&set->tag_list_lock);
|
|
|
|
if (set->nr_maps == 1 && nr_hw_queues > nr_cpu_ids)
|
|
nr_hw_queues = nr_cpu_ids;
|
|
if (nr_hw_queues < 1)
|
|
return;
|
|
if (set->nr_maps == 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);
|
|
/*
|
|
* Switch IO scheduler to 'none', cleaning up the data associated
|
|
* with the previous scheduler. We will switch back once we are done
|
|
* updating the new sw to hw queue mappings.
|
|
*/
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list)
|
|
if (!blk_mq_elv_switch_none(&head, q))
|
|
goto switch_back;
|
|
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list) {
|
|
blk_mq_debugfs_unregister_hctxs(q);
|
|
blk_mq_sysfs_unregister(q);
|
|
}
|
|
|
|
prev_nr_hw_queues = set->nr_hw_queues;
|
|
if (blk_mq_realloc_tag_set_tags(set, set->nr_hw_queues, nr_hw_queues) <
|
|
0)
|
|
goto reregister;
|
|
|
|
set->nr_hw_queues = nr_hw_queues;
|
|
fallback:
|
|
blk_mq_update_queue_map(set);
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list) {
|
|
blk_mq_realloc_hw_ctxs(set, q);
|
|
if (q->nr_hw_queues != set->nr_hw_queues) {
|
|
int i = prev_nr_hw_queues;
|
|
|
|
pr_warn("Increasing nr_hw_queues to %d fails, fallback to %d\n",
|
|
nr_hw_queues, prev_nr_hw_queues);
|
|
for (; i < set->nr_hw_queues; i++)
|
|
__blk_mq_free_map_and_rqs(set, i);
|
|
|
|
set->nr_hw_queues = prev_nr_hw_queues;
|
|
blk_mq_map_queues(&set->map[HCTX_TYPE_DEFAULT]);
|
|
goto fallback;
|
|
}
|
|
blk_mq_map_swqueue(q);
|
|
}
|
|
|
|
reregister:
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list) {
|
|
blk_mq_sysfs_register(q);
|
|
blk_mq_debugfs_register_hctxs(q);
|
|
}
|
|
|
|
switch_back:
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list)
|
|
blk_mq_elv_switch_back(&head, q);
|
|
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list)
|
|
blk_mq_unfreeze_queue(q);
|
|
}
|
|
|
|
void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
|
|
{
|
|
mutex_lock(&set->tag_list_lock);
|
|
__blk_mq_update_nr_hw_queues(set, nr_hw_queues);
|
|
mutex_unlock(&set->tag_list_lock);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
|
|
|
|
/* Enable polling stats and return whether they were already enabled. */
|
|
static bool blk_poll_stats_enable(struct request_queue *q)
|
|
{
|
|
if (q->poll_stat)
|
|
return true;
|
|
|
|
return blk_stats_alloc_enable(q);
|
|
}
|
|
|
|
static void blk_mq_poll_stats_start(struct request_queue *q)
|
|
{
|
|
/*
|
|
* We don't arm the callback if polling stats are not enabled or the
|
|
* callback is already active.
|
|
*/
|
|
if (!q->poll_stat || blk_stat_is_active(q->poll_cb))
|
|
return;
|
|
|
|
blk_stat_activate_msecs(q->poll_cb, 100);
|
|
}
|
|
|
|
static void blk_mq_poll_stats_fn(struct blk_stat_callback *cb)
|
|
{
|
|
struct request_queue *q = cb->data;
|
|
int bucket;
|
|
|
|
for (bucket = 0; bucket < BLK_MQ_POLL_STATS_BKTS; bucket++) {
|
|
if (cb->stat[bucket].nr_samples)
|
|
q->poll_stat[bucket] = cb->stat[bucket];
|
|
}
|
|
}
|
|
|
|
static unsigned long blk_mq_poll_nsecs(struct request_queue *q,
|
|
struct request *rq)
|
|
{
|
|
unsigned long ret = 0;
|
|
int bucket;
|
|
|
|
/*
|
|
* If stats collection isn't on, don't sleep but turn it on for
|
|
* future users
|
|
*/
|
|
if (!blk_poll_stats_enable(q))
|
|
return 0;
|
|
|
|
/*
|
|
* As an optimistic guess, use half of the mean service time
|
|
* for this type of request. We can (and should) make this smarter.
|
|
* For instance, if the completion latencies are tight, we can
|
|
* get closer than just half the mean. This is especially
|
|
* important on devices where the completion latencies are longer
|
|
* than ~10 usec. We do use the stats for the relevant IO size
|
|
* if available which does lead to better estimates.
|
|
*/
|
|
bucket = blk_mq_poll_stats_bkt(rq);
|
|
if (bucket < 0)
|
|
return ret;
|
|
|
|
if (q->poll_stat[bucket].nr_samples)
|
|
ret = (q->poll_stat[bucket].mean + 1) / 2;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool blk_mq_poll_hybrid(struct request_queue *q, blk_qc_t qc)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = blk_qc_to_hctx(q, qc);
|
|
struct request *rq = blk_qc_to_rq(hctx, qc);
|
|
struct hrtimer_sleeper hs;
|
|
enum hrtimer_mode mode;
|
|
unsigned int nsecs;
|
|
ktime_t kt;
|
|
|
|
/*
|
|
* If a request has completed on queue that uses an I/O scheduler, we
|
|
* won't get back a request from blk_qc_to_rq.
|
|
*/
|
|
if (!rq || (rq->rq_flags & RQF_MQ_POLL_SLEPT))
|
|
return false;
|
|
|
|
/*
|
|
* If we get here, hybrid polling is enabled. Hence poll_nsec can be:
|
|
*
|
|
* 0: use half of prev avg
|
|
* >0: use this specific value
|
|
*/
|
|
if (q->poll_nsec > 0)
|
|
nsecs = q->poll_nsec;
|
|
else
|
|
nsecs = blk_mq_poll_nsecs(q, rq);
|
|
|
|
if (!nsecs)
|
|
return false;
|
|
|
|
rq->rq_flags |= RQF_MQ_POLL_SLEPT;
|
|
|
|
/*
|
|
* This will be replaced with the stats tracking code, using
|
|
* 'avg_completion_time / 2' as the pre-sleep target.
|
|
*/
|
|
kt = nsecs;
|
|
|
|
mode = HRTIMER_MODE_REL;
|
|
hrtimer_init_sleeper_on_stack(&hs, CLOCK_MONOTONIC, mode);
|
|
hrtimer_set_expires(&hs.timer, kt);
|
|
|
|
do {
|
|
if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE)
|
|
break;
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
hrtimer_sleeper_start_expires(&hs, mode);
|
|
if (hs.task)
|
|
io_schedule();
|
|
hrtimer_cancel(&hs.timer);
|
|
mode = HRTIMER_MODE_ABS;
|
|
} while (hs.task && !signal_pending(current));
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
destroy_hrtimer_on_stack(&hs.timer);
|
|
|
|
/*
|
|
* If we sleep, have the caller restart the poll loop to reset the
|
|
* state. Like for the other success return cases, the caller is
|
|
* responsible for checking if the IO completed. If the IO isn't
|
|
* complete, we'll get called again and will go straight to the busy
|
|
* poll loop.
|
|
*/
|
|
return true;
|
|
}
|
|
|
|
static int blk_mq_poll_classic(struct request_queue *q, blk_qc_t cookie,
|
|
struct io_comp_batch *iob, unsigned int flags)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = blk_qc_to_hctx(q, cookie);
|
|
long state = get_current_state();
|
|
int ret;
|
|
|
|
do {
|
|
ret = q->mq_ops->poll(hctx, iob);
|
|
if (ret > 0) {
|
|
__set_current_state(TASK_RUNNING);
|
|
return ret;
|
|
}
|
|
|
|
if (signal_pending_state(state, current))
|
|
__set_current_state(TASK_RUNNING);
|
|
if (task_is_running(current))
|
|
return 1;
|
|
|
|
if (ret < 0 || (flags & BLK_POLL_ONESHOT))
|
|
break;
|
|
cpu_relax();
|
|
} while (!need_resched());
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
return 0;
|
|
}
|
|
|
|
int blk_mq_poll(struct request_queue *q, blk_qc_t cookie, struct io_comp_batch *iob,
|
|
unsigned int flags)
|
|
{
|
|
if (!(flags & BLK_POLL_NOSLEEP) &&
|
|
q->poll_nsec != BLK_MQ_POLL_CLASSIC) {
|
|
if (blk_mq_poll_hybrid(q, cookie))
|
|
return 1;
|
|
}
|
|
return blk_mq_poll_classic(q, cookie, iob, flags);
|
|
}
|
|
|
|
unsigned int blk_mq_rq_cpu(struct request *rq)
|
|
{
|
|
return rq->mq_ctx->cpu;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_rq_cpu);
|
|
|
|
void blk_mq_cancel_work_sync(struct request_queue *q)
|
|
{
|
|
if (queue_is_mq(q)) {
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
cancel_delayed_work_sync(&q->requeue_work);
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
cancel_delayed_work_sync(&hctx->run_work);
|
|
}
|
|
}
|
|
|
|
static int __init blk_mq_init(void)
|
|
{
|
|
int i;
|
|
|
|
for_each_possible_cpu(i)
|
|
init_llist_head(&per_cpu(blk_cpu_done, i));
|
|
open_softirq(BLOCK_SOFTIRQ, blk_done_softirq);
|
|
|
|
cpuhp_setup_state_nocalls(CPUHP_BLOCK_SOFTIRQ_DEAD,
|
|
"block/softirq:dead", NULL,
|
|
blk_softirq_cpu_dead);
|
|
cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,
|
|
blk_mq_hctx_notify_dead);
|
|
cpuhp_setup_state_multi(CPUHP_AP_BLK_MQ_ONLINE, "block/mq:online",
|
|
blk_mq_hctx_notify_online,
|
|
blk_mq_hctx_notify_offline);
|
|
return 0;
|
|
}
|
|
subsys_initcall(blk_mq_init);
|