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![Linus Torvalds](/assets/img/avatar_default.png)
-----BEGIN PGP SIGNATURE----- iQJEBAABCAAuFiEEwPw5LcreJtl1+l5K99NY+ylx4KYFAls2oVcQHGF4Ym9lQGtl cm5lbC5kawAKCRD301j7KXHgpr89D/9PaJCtLpCEU1HdaohIDXDyJKBdtCllIsqJ YAJTlUkFRkMvsbdEA3U43rVRVlu7zxP3aRg79VRI+kdZ8y8XSiisAF/QUbG/Bwd3 NuFqKj4Hm5xFTtLMKIUlumR2/exD4ZpPHKnWmD4idp1PZRoTUwxeIjqVv77L6Nfy c4/GVlz2t9buWxH/5PSa//rsT49xM6CLpyIwO2lFsNEk2HYE/uAWya5KZVJ1YKVw mSjUdyFtJ//lFK9lVU4YkdNF0d5w2PcEoCfNyPe0n9F43iITACo2om7rkSkTgciS izPAs1DkqNdWPta2twULt656WlUoGlwnWyFchU34N/I/pDiww4kdCQFfNIOi6qBW 7rPQ4xpywiw/U93C2GLEeE09++T8+yO4KuELhIcN5+D3D2VGRIuaGcf4xeY0CX3A a335EZIxBGOfxyejknBDg3BsoUcLvejbANKD8ltis3zciGf/QyLt+FFqx25WCzkN N028ppml8WPSiqhSlFDMyfscO1dx/WSYh1q7ANrBiPPaEjFYmakzEDT0cZW4JsUh av4jqYt3cqrFIXyhRHJM2wjFymQv6aVnmLa4zOKCFbwm9KzMWUUFjc4R962T/sQK 0g+eCSFGidii4JZ4ghOAQk2dqCTIZqV72pmLlpJBGu+SAIQxkh+29h0LOi5U3v1Y FnTtJ1JhCg== =0uqV -----END PGP SIGNATURE----- Merge tag 'for-linus-20180629' of git://git.kernel.dk/linux-block Pull block fixes from Jens Axboe: "Small set of fixes for this series. Mostly just minor fixes, the only oddball in here is the sg change. The sg change came out of the stall fix for NVMe, where we added a mempool and limited us to a single page allocation. CONFIG_SG_DEBUG sort-of ruins that, since we'd need to account for that. That's actually a generic problem, since lots of drivers need to allocate SG lists. So this just removes support for CONFIG_SG_DEBUG, which I added back in 2007 and to my knowledge it was never useful. Anyway, outside of that, this pull contains: - clone of request with special payload fix (Bart) - drbd discard handling fix (Bart) - SATA blk-mq stall fix (me) - chunk size fix (Keith) - double free nvme rdma fix (Sagi)" * tag 'for-linus-20180629' of git://git.kernel.dk/linux-block: sg: remove ->sg_magic member drbd: Fix drbd_request_prepare() discard handling blk-mq: don't queue more if we get a busy return block: Fix cloning of requests with a special payload nvme-rdma: fix possible double free of controller async event buffer block: Fix transfer when chunk sectors exceeds max
3083 lines
74 KiB
C
3083 lines
74 KiB
C
/*
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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/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/llist.h>
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#include <linux/list_sort.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 <trace/events/block.h>
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#include <linux/blk-mq.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-stat.h"
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#include "blk-wbt.h"
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#include "blk-mq-sched.h"
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static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie);
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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, bytes, bucket;
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ddir = rq_data_dir(rq);
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bytes = blk_rq_bytes(rq);
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bucket = ddir + 2*(ilog2(bytes) - 9);
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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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/*
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* Check if any of the ctx's 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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if (!sbitmap_test_bit(&hctx->ctx_map, ctx->index_hw))
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sbitmap_set_bit(&hctx->ctx_map, ctx->index_hw);
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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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sbitmap_clear_bit(&hctx->ctx_map, ctx->index_hw);
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}
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struct mq_inflight {
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struct hd_struct *part;
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unsigned int *inflight;
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};
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static void blk_mq_check_inflight(struct blk_mq_hw_ctx *hctx,
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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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/*
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* index[0] counts the specific partition that was asked for. index[1]
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* counts the ones that are active on the whole device, so increment
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* that if mi->part is indeed a partition, and not a whole device.
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*/
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if (rq->part == mi->part)
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mi->inflight[0]++;
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if (mi->part->partno)
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mi->inflight[1]++;
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}
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void blk_mq_in_flight(struct request_queue *q, struct hd_struct *part,
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unsigned int inflight[2])
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{
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struct mq_inflight mi = { .part = part, .inflight = inflight, };
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inflight[0] = inflight[1] = 0;
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blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight, &mi);
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}
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static void blk_mq_check_inflight_rw(struct blk_mq_hw_ctx *hctx,
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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 (rq->part == mi->part)
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mi->inflight[rq_data_dir(rq)]++;
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}
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void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part,
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unsigned int inflight[2])
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{
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struct mq_inflight mi = { .part = part, .inflight = inflight, };
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inflight[0] = inflight[1] = 0;
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blk_mq_queue_tag_busy_iter(q, blk_mq_check_inflight_rw, &mi);
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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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int freeze_depth;
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freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
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if (freeze_depth == 1) {
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percpu_ref_kill(&q->q_usage_counter);
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if (q->mq_ops)
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blk_mq_run_hw_queues(q, false);
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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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if (!q->mq_ops)
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blk_drain_queue(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)
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{
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int freeze_depth;
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freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
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WARN_ON_ONCE(freeze_depth < 0);
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if (!freeze_depth) {
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percpu_ref_reinit(&q->q_usage_counter);
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wake_up_all(&q->mq_freeze_wq);
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}
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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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blk_queue_flag_set(QUEUE_FLAG_QUIESCED, q);
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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_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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struct blk_mq_hw_ctx *hctx;
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unsigned int i;
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bool rcu = false;
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blk_mq_quiesce_queue_nowait(q);
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queue_for_each_hw_ctx(q, hctx, i) {
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if (hctx->flags & BLK_MQ_F_BLOCKING)
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synchronize_srcu(hctx->srcu);
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else
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rcu = true;
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}
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if (rcu)
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synchronize_rcu();
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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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blk_queue_flag_clear(QUEUE_FLAG_QUIESCED, q);
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/* dispatch requests which are inserted during quiescing */
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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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bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
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{
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return blk_mq_has_free_tags(hctx->tags);
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}
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EXPORT_SYMBOL(blk_mq_can_queue);
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static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
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unsigned int tag, unsigned int op)
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{
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struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
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struct request *rq = tags->static_rqs[tag];
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req_flags_t rq_flags = 0;
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if (data->flags & BLK_MQ_REQ_INTERNAL) {
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rq->tag = -1;
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rq->internal_tag = tag;
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} else {
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if (blk_mq_tag_busy(data->hctx)) {
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rq_flags = RQF_MQ_INFLIGHT;
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atomic_inc(&data->hctx->nr_active);
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}
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rq->tag = tag;
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rq->internal_tag = -1;
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data->hctx->tags->rqs[rq->tag] = rq;
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}
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/* csd/requeue_work/fifo_time is initialized before use */
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rq->q = data->q;
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rq->mq_ctx = data->ctx;
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rq->rq_flags = rq_flags;
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rq->cpu = -1;
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rq->cmd_flags = op;
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if (data->flags & BLK_MQ_REQ_PREEMPT)
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rq->rq_flags |= RQF_PREEMPT;
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if (blk_queue_io_stat(data->q))
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rq->rq_flags |= RQF_IO_STAT;
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INIT_LIST_HEAD(&rq->queuelist);
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INIT_HLIST_NODE(&rq->hash);
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RB_CLEAR_NODE(&rq->rb_node);
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rq->rq_disk = NULL;
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rq->part = NULL;
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rq->start_time_ns = ktime_get_ns();
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rq->io_start_time_ns = 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->special = NULL;
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/* tag was already set */
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rq->extra_len = 0;
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rq->__deadline = 0;
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INIT_LIST_HEAD(&rq->timeout_list);
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rq->timeout = 0;
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rq->end_io = NULL;
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rq->end_io_data = NULL;
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rq->next_rq = NULL;
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#ifdef CONFIG_BLK_CGROUP
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rq->rl = NULL;
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#endif
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data->ctx->rq_dispatched[op_is_sync(op)]++;
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refcount_set(&rq->ref, 1);
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return rq;
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}
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static struct request *blk_mq_get_request(struct request_queue *q,
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struct bio *bio, unsigned int op,
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struct blk_mq_alloc_data *data)
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{
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struct elevator_queue *e = q->elevator;
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struct request *rq;
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unsigned int tag;
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bool put_ctx_on_error = false;
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blk_queue_enter_live(q);
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data->q = q;
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if (likely(!data->ctx)) {
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data->ctx = blk_mq_get_ctx(q);
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put_ctx_on_error = true;
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}
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if (likely(!data->hctx))
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data->hctx = blk_mq_map_queue(q, data->ctx->cpu);
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if (op & REQ_NOWAIT)
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data->flags |= BLK_MQ_REQ_NOWAIT;
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if (e) {
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data->flags |= BLK_MQ_REQ_INTERNAL;
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/*
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* Flush 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(op) && e->type->ops.mq.limit_depth &&
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!(data->flags & BLK_MQ_REQ_RESERVED))
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e->type->ops.mq.limit_depth(op, data);
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}
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tag = blk_mq_get_tag(data);
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if (tag == BLK_MQ_TAG_FAIL) {
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if (put_ctx_on_error) {
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blk_mq_put_ctx(data->ctx);
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data->ctx = NULL;
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}
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blk_queue_exit(q);
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return NULL;
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}
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rq = blk_mq_rq_ctx_init(data, tag, op);
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if (!op_is_flush(op)) {
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rq->elv.icq = NULL;
|
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if (e && e->type->ops.mq.prepare_request) {
|
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if (e->type->icq_cache && rq_ioc(bio))
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blk_mq_sched_assign_ioc(rq, bio);
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|
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e->type->ops.mq.prepare_request(rq, bio);
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rq->rq_flags |= RQF_ELVPRIV;
|
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}
|
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}
|
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data->hctx->queued++;
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return rq;
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}
|
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|
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struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
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blk_mq_req_flags_t flags)
|
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{
|
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struct blk_mq_alloc_data alloc_data = { .flags = flags };
|
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struct request *rq;
|
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int ret;
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|
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ret = blk_queue_enter(q, flags);
|
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if (ret)
|
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return ERR_PTR(ret);
|
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|
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rq = blk_mq_get_request(q, NULL, op, &alloc_data);
|
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blk_queue_exit(q);
|
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|
|
if (!rq)
|
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return ERR_PTR(-EWOULDBLOCK);
|
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|
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blk_mq_put_ctx(alloc_data.ctx);
|
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|
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rq->__data_len = 0;
|
|
rq->__sector = (sector_t) -1;
|
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rq->bio = rq->biotail = NULL;
|
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return rq;
|
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}
|
|
EXPORT_SYMBOL(blk_mq_alloc_request);
|
|
|
|
struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
|
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unsigned int op, blk_mq_req_flags_t flags, unsigned int hctx_idx)
|
|
{
|
|
struct blk_mq_alloc_data alloc_data = { .flags = flags };
|
|
struct request *rq;
|
|
unsigned int cpu;
|
|
int ret;
|
|
|
|
/*
|
|
* 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)))
|
|
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.
|
|
*/
|
|
alloc_data.hctx = q->queue_hw_ctx[hctx_idx];
|
|
if (!blk_mq_hw_queue_mapped(alloc_data.hctx)) {
|
|
blk_queue_exit(q);
|
|
return ERR_PTR(-EXDEV);
|
|
}
|
|
cpu = cpumask_first_and(alloc_data.hctx->cpumask, cpu_online_mask);
|
|
alloc_data.ctx = __blk_mq_get_ctx(q, cpu);
|
|
|
|
rq = blk_mq_get_request(q, NULL, op, &alloc_data);
|
|
blk_queue_exit(q);
|
|
|
|
if (!rq)
|
|
return ERR_PTR(-EWOULDBLOCK);
|
|
|
|
return rq;
|
|
}
|
|
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 = blk_mq_map_queue(q, ctx->cpu);
|
|
const int sched_tag = rq->internal_tag;
|
|
|
|
if (rq->tag != -1)
|
|
blk_mq_put_tag(hctx, hctx->tags, ctx, rq->tag);
|
|
if (sched_tag != -1)
|
|
blk_mq_put_tag(hctx, 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 elevator_queue *e = q->elevator;
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx;
|
|
struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(q, ctx->cpu);
|
|
|
|
if (rq->rq_flags & RQF_ELVPRIV) {
|
|
if (e && e->type->ops.mq.finish_request)
|
|
e->type->ops.mq.finish_request(rq);
|
|
if (rq->elv.icq) {
|
|
put_io_context(rq->elv.icq->ioc);
|
|
rq->elv.icq = NULL;
|
|
}
|
|
}
|
|
|
|
ctx->rq_completed[rq_is_sync(rq)]++;
|
|
if (rq->rq_flags & RQF_MQ_INFLIGHT)
|
|
atomic_dec(&hctx->nr_active);
|
|
|
|
if (unlikely(laptop_mode && !blk_rq_is_passthrough(rq)))
|
|
laptop_io_completion(q->backing_dev_info);
|
|
|
|
wbt_done(q->rq_wb, rq);
|
|
|
|
if (blk_rq_rl(rq))
|
|
blk_put_rl(blk_rq_rl(rq));
|
|
|
|
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
|
|
if (refcount_dec_and_test(&rq->ref))
|
|
__blk_mq_free_request(rq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_free_request);
|
|
|
|
inline void __blk_mq_end_request(struct request *rq, blk_status_t error)
|
|
{
|
|
u64 now = ktime_get_ns();
|
|
|
|
if (rq->rq_flags & RQF_STATS) {
|
|
blk_mq_poll_stats_start(rq->q);
|
|
blk_stat_add(rq, now);
|
|
}
|
|
|
|
blk_account_io_done(rq, now);
|
|
|
|
if (rq->end_io) {
|
|
wbt_done(rq->q->rq_wb, rq);
|
|
rq->end_io(rq, error);
|
|
} else {
|
|
if (unlikely(blk_bidi_rq(rq)))
|
|
blk_mq_free_request(rq->next_rq);
|
|
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);
|
|
|
|
static void __blk_mq_complete_request_remote(void *data)
|
|
{
|
|
struct request *rq = data;
|
|
|
|
rq->q->softirq_done_fn(rq);
|
|
}
|
|
|
|
static void __blk_mq_complete_request(struct request *rq)
|
|
{
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx;
|
|
bool shared = false;
|
|
int cpu;
|
|
|
|
if (cmpxchg(&rq->state, MQ_RQ_IN_FLIGHT, MQ_RQ_COMPLETE) !=
|
|
MQ_RQ_IN_FLIGHT)
|
|
return;
|
|
|
|
if (rq->internal_tag != -1)
|
|
blk_mq_sched_completed_request(rq);
|
|
|
|
if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
|
|
rq->q->softirq_done_fn(rq);
|
|
return;
|
|
}
|
|
|
|
cpu = get_cpu();
|
|
if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
|
|
shared = cpus_share_cache(cpu, ctx->cpu);
|
|
|
|
if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
|
|
rq->csd.func = __blk_mq_complete_request_remote;
|
|
rq->csd.info = rq;
|
|
rq->csd.flags = 0;
|
|
smp_call_function_single_async(ctx->cpu, &rq->csd);
|
|
} else {
|
|
rq->q->softirq_done_fn(rq);
|
|
}
|
|
put_cpu();
|
|
}
|
|
|
|
static void hctx_unlock(struct blk_mq_hw_ctx *hctx, int srcu_idx)
|
|
__releases(hctx->srcu)
|
|
{
|
|
if (!(hctx->flags & BLK_MQ_F_BLOCKING))
|
|
rcu_read_unlock();
|
|
else
|
|
srcu_read_unlock(hctx->srcu, srcu_idx);
|
|
}
|
|
|
|
static void hctx_lock(struct blk_mq_hw_ctx *hctx, int *srcu_idx)
|
|
__acquires(hctx->srcu)
|
|
{
|
|
if (!(hctx->flags & BLK_MQ_F_BLOCKING)) {
|
|
/* shut up gcc false positive */
|
|
*srcu_idx = 0;
|
|
rcu_read_lock();
|
|
} else
|
|
*srcu_idx = srcu_read_lock(hctx->srcu);
|
|
}
|
|
|
|
/**
|
|
* blk_mq_complete_request - end I/O on a request
|
|
* @rq: the request being processed
|
|
*
|
|
* Description:
|
|
* Ends all I/O on a request. It does not handle partial completions.
|
|
* The actual completion happens out-of-order, through a IPI handler.
|
|
**/
|
|
void blk_mq_complete_request(struct request *rq)
|
|
{
|
|
if (unlikely(blk_should_fake_timeout(rq->q)))
|
|
return;
|
|
__blk_mq_complete_request(rq);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_complete_request);
|
|
|
|
int blk_mq_request_started(struct request *rq)
|
|
{
|
|
return blk_mq_rq_state(rq) != MQ_RQ_IDLE;
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_request_started);
|
|
|
|
void blk_mq_start_request(struct request *rq)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
|
|
blk_mq_sched_started_request(rq);
|
|
|
|
trace_block_rq_issue(q, rq);
|
|
|
|
if (test_bit(QUEUE_FLAG_STATS, &q->queue_flags)) {
|
|
rq->io_start_time_ns = ktime_get_ns();
|
|
#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
|
|
rq->throtl_size = blk_rq_sectors(rq);
|
|
#endif
|
|
rq->rq_flags |= RQF_STATS;
|
|
wbt_issue(q->rq_wb, rq);
|
|
}
|
|
|
|
WARN_ON_ONCE(blk_mq_rq_state(rq) != MQ_RQ_IDLE);
|
|
|
|
blk_add_timer(rq);
|
|
WRITE_ONCE(rq->state, MQ_RQ_IN_FLIGHT);
|
|
|
|
if (q->dma_drain_size && blk_rq_bytes(rq)) {
|
|
/*
|
|
* Make sure space for the drain appears. We know we can do
|
|
* this because max_hw_segments has been adjusted to be one
|
|
* fewer than the device can handle.
|
|
*/
|
|
rq->nr_phys_segments++;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_start_request);
|
|
|
|
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(q, rq);
|
|
wbt_requeue(q->rq_wb, rq);
|
|
|
|
if (blk_mq_request_started(rq)) {
|
|
WRITE_ONCE(rq->state, MQ_RQ_IDLE);
|
|
rq->rq_flags &= ~RQF_TIMED_OUT;
|
|
if (q->dma_drain_size && blk_rq_bytes(rq))
|
|
rq->nr_phys_segments--;
|
|
}
|
|
}
|
|
|
|
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);
|
|
|
|
BUG_ON(blk_queued_rq(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))
|
|
continue;
|
|
|
|
rq->rq_flags &= ~RQF_SOFTBARRIER;
|
|
list_del_init(&rq->queuelist);
|
|
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);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
|
|
|
|
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);
|
|
|
|
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
|
|
{
|
|
if (tag < tags->nr_tags) {
|
|
prefetch(tags->rqs[tag]);
|
|
return tags->rqs[tag];
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_tag_to_rq);
|
|
|
|
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 = blk_rq_deadline(rq);
|
|
if (time_after_eq(jiffies, deadline))
|
|
return true;
|
|
|
|
if (*next == 0)
|
|
*next = deadline;
|
|
else if (time_after(*next, deadline))
|
|
*next = deadline;
|
|
return false;
|
|
}
|
|
|
|
static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq, void *priv, bool reserved)
|
|
{
|
|
unsigned long *next = priv;
|
|
|
|
/*
|
|
* Just do a quick check if it is expired before locking the request in
|
|
* so we're not unnecessarilly synchronizing across CPUs.
|
|
*/
|
|
if (!blk_mq_req_expired(rq, next))
|
|
return;
|
|
|
|
/*
|
|
* We have reason to believe the request may be expired. Take a
|
|
* reference on the request to lock this request lifetime into its
|
|
* currently allocated context to prevent it from being reallocated in
|
|
* the event the completion by-passes this timeout handler.
|
|
*
|
|
* If the reference was already released, then the driver beat the
|
|
* timeout handler to posting a natural completion.
|
|
*/
|
|
if (!refcount_inc_not_zero(&rq->ref))
|
|
return;
|
|
|
|
/*
|
|
* The request is now locked and cannot be reallocated underneath the
|
|
* timeout handler's processing. Re-verify this exact request is truly
|
|
* expired; if it is not expired, then the request was completed and
|
|
* reallocated as a new request.
|
|
*/
|
|
if (blk_mq_req_expired(rq, next))
|
|
blk_mq_rq_timed_out(rq, reserved);
|
|
if (refcount_dec_and_test(&rq->ref))
|
|
__blk_mq_free_request(rq);
|
|
}
|
|
|
|
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];
|
|
|
|
spin_lock(&ctx->lock);
|
|
list_splice_tail_init(&ctx->rq_list, 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];
|
|
|
|
spin_lock(&ctx->lock);
|
|
if (!list_empty(&ctx->rq_list)) {
|
|
dispatch_data->rq = list_entry_rq(ctx->rq_list.next);
|
|
list_del_init(&dispatch_data->rq->queuelist);
|
|
if (list_empty(&ctx->rq_list))
|
|
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 : 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 inline unsigned int queued_to_index(unsigned int queued)
|
|
{
|
|
if (!queued)
|
|
return 0;
|
|
|
|
return min(BLK_MQ_MAX_DISPATCH_ORDER - 1, ilog2(queued) + 1);
|
|
}
|
|
|
|
bool blk_mq_get_driver_tag(struct request *rq, struct blk_mq_hw_ctx **hctx,
|
|
bool wait)
|
|
{
|
|
struct blk_mq_alloc_data data = {
|
|
.q = rq->q,
|
|
.hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu),
|
|
.flags = wait ? 0 : BLK_MQ_REQ_NOWAIT,
|
|
};
|
|
|
|
might_sleep_if(wait);
|
|
|
|
if (rq->tag != -1)
|
|
goto done;
|
|
|
|
if (blk_mq_tag_is_reserved(data.hctx->sched_tags, rq->internal_tag))
|
|
data.flags |= BLK_MQ_REQ_RESERVED;
|
|
|
|
rq->tag = blk_mq_get_tag(&data);
|
|
if (rq->tag >= 0) {
|
|
if (blk_mq_tag_busy(data.hctx)) {
|
|
rq->rq_flags |= RQF_MQ_INFLIGHT;
|
|
atomic_inc(&data.hctx->nr_active);
|
|
}
|
|
data.hctx->tags->rqs[rq->tag] = rq;
|
|
}
|
|
|
|
done:
|
|
if (hctx)
|
|
*hctx = data.hctx;
|
|
return rq->tag != -1;
|
|
}
|
|
|
|
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);
|
|
|
|
list_del_init(&wait->entry);
|
|
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 blk_mq_hw_ctx *this_hctx = *hctx;
|
|
struct sbq_wait_state *ws;
|
|
wait_queue_entry_t *wait;
|
|
bool ret;
|
|
|
|
if (!(this_hctx->flags & BLK_MQ_F_TAG_SHARED)) {
|
|
if (!test_bit(BLK_MQ_S_SCHED_RESTART, &this_hctx->state))
|
|
set_bit(BLK_MQ_S_SCHED_RESTART, &this_hctx->state);
|
|
|
|
/*
|
|
* 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, hctx, false);
|
|
}
|
|
|
|
wait = &this_hctx->dispatch_wait;
|
|
if (!list_empty_careful(&wait->entry))
|
|
return false;
|
|
|
|
spin_lock(&this_hctx->lock);
|
|
if (!list_empty(&wait->entry)) {
|
|
spin_unlock(&this_hctx->lock);
|
|
return false;
|
|
}
|
|
|
|
ws = bt_wait_ptr(&this_hctx->tags->bitmap_tags, this_hctx);
|
|
add_wait_queue(&ws->wait, 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, hctx, false);
|
|
if (!ret) {
|
|
spin_unlock(&this_hctx->lock);
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* We got a tag, remove ourselves from the wait queue to ensure
|
|
* someone else gets the wakeup.
|
|
*/
|
|
spin_lock_irq(&ws->wait.lock);
|
|
list_del_init(&wait->entry);
|
|
spin_unlock_irq(&ws->wait.lock);
|
|
spin_unlock(&this_hctx->lock);
|
|
|
|
return true;
|
|
}
|
|
|
|
#define BLK_MQ_RESOURCE_DELAY 3 /* ms units */
|
|
|
|
/*
|
|
* Returns true if we did some work AND can potentially do more.
|
|
*/
|
|
bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
|
|
bool got_budget)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct request *rq, *nxt;
|
|
bool no_tag = false;
|
|
int errors, queued;
|
|
blk_status_t ret = BLK_STS_OK;
|
|
|
|
if (list_empty(list))
|
|
return false;
|
|
|
|
WARN_ON(!list_is_singular(list) && got_budget);
|
|
|
|
/*
|
|
* 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);
|
|
|
|
hctx = blk_mq_map_queue(rq->q, rq->mq_ctx->cpu);
|
|
if (!got_budget && !blk_mq_get_dispatch_budget(hctx))
|
|
break;
|
|
|
|
if (!blk_mq_get_driver_tag(rq, NULL, false)) {
|
|
/*
|
|
* 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)) {
|
|
blk_mq_put_dispatch_budget(hctx);
|
|
/*
|
|
* For non-shared tags, the RESTART check
|
|
* will suffice.
|
|
*/
|
|
if (hctx->flags & BLK_MQ_F_TAG_SHARED)
|
|
no_tag = true;
|
|
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, NULL, false);
|
|
}
|
|
|
|
ret = q->mq_ops->queue_rq(hctx, &bd);
|
|
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE) {
|
|
/*
|
|
* If an I/O scheduler has been configured and we got a
|
|
* driver tag for the next request already, free it
|
|
* again.
|
|
*/
|
|
if (!list_empty(list)) {
|
|
nxt = list_first_entry(list, struct request, queuelist);
|
|
blk_mq_put_driver_tag(nxt);
|
|
}
|
|
list_add(&rq->queuelist, list);
|
|
__blk_mq_requeue_request(rq);
|
|
break;
|
|
}
|
|
|
|
if (unlikely(ret != BLK_STS_OK)) {
|
|
errors++;
|
|
blk_mq_end_request(rq, BLK_STS_IOERR);
|
|
continue;
|
|
}
|
|
|
|
queued++;
|
|
} while (!list_empty(list));
|
|
|
|
hctx->dispatched[queued_to_index(queued)]++;
|
|
|
|
/*
|
|
* 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;
|
|
|
|
spin_lock(&hctx->lock);
|
|
list_splice_init(list, &hctx->dispatch);
|
|
spin_unlock(&hctx->lock);
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
needs_restart = blk_mq_sched_needs_restart(hctx);
|
|
if (!needs_restart ||
|
|
(no_tag && list_empty_careful(&hctx->dispatch_wait.entry)))
|
|
blk_mq_run_hw_queue(hctx, true);
|
|
else if (needs_restart && (ret == BLK_STS_RESOURCE))
|
|
blk_mq_delay_run_hw_queue(hctx, BLK_MQ_RESOURCE_DELAY);
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* If the host/device is unable to accept more work, inform the
|
|
* caller of that.
|
|
*/
|
|
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE)
|
|
return false;
|
|
|
|
return (queued + errors) != 0;
|
|
}
|
|
|
|
static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
int srcu_idx;
|
|
|
|
/*
|
|
* We should be running this queue from one of the CPUs that
|
|
* are mapped to it.
|
|
*
|
|
* There are at least two related races now between setting
|
|
* hctx->next_cpu from blk_mq_hctx_next_cpu() and running
|
|
* __blk_mq_run_hw_queue():
|
|
*
|
|
* - hctx->next_cpu is found offline in blk_mq_hctx_next_cpu(),
|
|
* but later it becomes online, then this warning is harmless
|
|
* at all
|
|
*
|
|
* - hctx->next_cpu is found online in blk_mq_hctx_next_cpu(),
|
|
* but later it becomes offline, then the warning can't be
|
|
* triggered, and we depend on blk-mq timeout handler to
|
|
* handle dispatched requests to this hctx
|
|
*/
|
|
if (!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask) &&
|
|
cpu_online(hctx->next_cpu)) {
|
|
printk(KERN_WARNING "run queue from wrong CPU %d, hctx %s\n",
|
|
raw_smp_processor_id(),
|
|
cpumask_empty(hctx->cpumask) ? "inactive": "active");
|
|
dump_stack();
|
|
}
|
|
|
|
/*
|
|
* We can't run the queue inline with ints disabled. Ensure that
|
|
* we catch bad users of this early.
|
|
*/
|
|
WARN_ON_ONCE(in_interrupt());
|
|
|
|
might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
|
|
|
|
hctx_lock(hctx, &srcu_idx);
|
|
blk_mq_sched_dispatch_requests(hctx);
|
|
hctx_unlock(hctx, srcu_idx);
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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));
|
|
}
|
|
|
|
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);
|
|
|
|
bool blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
|
|
{
|
|
int srcu_idx;
|
|
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.
|
|
*/
|
|
hctx_lock(hctx, &srcu_idx);
|
|
need_run = !blk_queue_quiesced(hctx->queue) &&
|
|
blk_mq_hctx_has_pending(hctx);
|
|
hctx_unlock(hctx, srcu_idx);
|
|
|
|
if (need_run) {
|
|
__blk_mq_delay_run_hw_queue(hctx, async, 0);
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_run_hw_queue);
|
|
|
|
void blk_mq_run_hw_queues(struct request_queue *q, bool async)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (blk_mq_hctx_stopped(hctx))
|
|
continue;
|
|
|
|
blk_mq_run_hw_queue(hctx, async);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_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 (test_bit(BLK_MQ_S_STOPPED, &hctx->state))
|
|
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;
|
|
|
|
lockdep_assert_held(&ctx->lock);
|
|
|
|
trace_block_rq_insert(hctx->queue, rq);
|
|
|
|
if (at_head)
|
|
list_add(&rq->queuelist, &ctx->rq_list);
|
|
else
|
|
list_add_tail(&rq->queuelist, &ctx->rq_list);
|
|
}
|
|
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* 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 run_queue)
|
|
{
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx;
|
|
struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(rq->q, ctx->cpu);
|
|
|
|
spin_lock(&hctx->lock);
|
|
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)
|
|
|
|
{
|
|
/*
|
|
* preemption doesn't flush plug list, so it's possible ctx->cpu is
|
|
* offline now
|
|
*/
|
|
spin_lock(&ctx->lock);
|
|
while (!list_empty(list)) {
|
|
struct request *rq;
|
|
|
|
rq = list_first_entry(list, struct request, queuelist);
|
|
BUG_ON(rq->mq_ctx != ctx);
|
|
list_del_init(&rq->queuelist);
|
|
__blk_mq_insert_req_list(hctx, rq, false);
|
|
}
|
|
blk_mq_hctx_mark_pending(hctx, ctx);
|
|
spin_unlock(&ctx->lock);
|
|
}
|
|
|
|
static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
|
|
{
|
|
struct request *rqa = container_of(a, struct request, queuelist);
|
|
struct request *rqb = container_of(b, struct request, queuelist);
|
|
|
|
return !(rqa->mq_ctx < rqb->mq_ctx ||
|
|
(rqa->mq_ctx == rqb->mq_ctx &&
|
|
blk_rq_pos(rqa) < blk_rq_pos(rqb)));
|
|
}
|
|
|
|
void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
|
|
{
|
|
struct blk_mq_ctx *this_ctx;
|
|
struct request_queue *this_q;
|
|
struct request *rq;
|
|
LIST_HEAD(list);
|
|
LIST_HEAD(ctx_list);
|
|
unsigned int depth;
|
|
|
|
list_splice_init(&plug->mq_list, &list);
|
|
|
|
list_sort(NULL, &list, plug_ctx_cmp);
|
|
|
|
this_q = NULL;
|
|
this_ctx = NULL;
|
|
depth = 0;
|
|
|
|
while (!list_empty(&list)) {
|
|
rq = list_entry_rq(list.next);
|
|
list_del_init(&rq->queuelist);
|
|
BUG_ON(!rq->q);
|
|
if (rq->mq_ctx != this_ctx) {
|
|
if (this_ctx) {
|
|
trace_block_unplug(this_q, depth, from_schedule);
|
|
blk_mq_sched_insert_requests(this_q, this_ctx,
|
|
&ctx_list,
|
|
from_schedule);
|
|
}
|
|
|
|
this_ctx = rq->mq_ctx;
|
|
this_q = rq->q;
|
|
depth = 0;
|
|
}
|
|
|
|
depth++;
|
|
list_add_tail(&rq->queuelist, &ctx_list);
|
|
}
|
|
|
|
/*
|
|
* If 'this_ctx' is set, we know we have entries to complete
|
|
* on 'ctx_list'. Do those.
|
|
*/
|
|
if (this_ctx) {
|
|
trace_block_unplug(this_q, depth, from_schedule);
|
|
blk_mq_sched_insert_requests(this_q, this_ctx, &ctx_list,
|
|
from_schedule);
|
|
}
|
|
}
|
|
|
|
static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
|
|
{
|
|
blk_init_request_from_bio(rq, bio);
|
|
|
|
blk_rq_set_rl(rq, blk_get_rl(rq->q, bio));
|
|
|
|
blk_account_io_start(rq, true);
|
|
}
|
|
|
|
static blk_qc_t request_to_qc_t(struct blk_mq_hw_ctx *hctx, struct request *rq)
|
|
{
|
|
if (rq->tag != -1)
|
|
return blk_tag_to_qc_t(rq->tag, hctx->queue_num, false);
|
|
|
|
return blk_tag_to_qc_t(rq->internal_tag, hctx->queue_num, true);
|
|
}
|
|
|
|
static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq,
|
|
blk_qc_t *cookie)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
struct blk_mq_queue_data bd = {
|
|
.rq = rq,
|
|
.last = true,
|
|
};
|
|
blk_qc_t new_cookie;
|
|
blk_status_t ret;
|
|
|
|
new_cookie = request_to_qc_t(hctx, rq);
|
|
|
|
/*
|
|
* 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:
|
|
*cookie = new_cookie;
|
|
break;
|
|
case BLK_STS_RESOURCE:
|
|
case BLK_STS_DEV_RESOURCE:
|
|
__blk_mq_requeue_request(rq);
|
|
break;
|
|
default:
|
|
*cookie = BLK_QC_T_NONE;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq,
|
|
blk_qc_t *cookie,
|
|
bool bypass_insert)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
bool run_queue = true;
|
|
|
|
/*
|
|
* 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 (q->elevator && !bypass_insert)
|
|
goto insert;
|
|
|
|
if (!blk_mq_get_dispatch_budget(hctx))
|
|
goto insert;
|
|
|
|
if (!blk_mq_get_driver_tag(rq, NULL, false)) {
|
|
blk_mq_put_dispatch_budget(hctx);
|
|
goto insert;
|
|
}
|
|
|
|
return __blk_mq_issue_directly(hctx, rq, cookie);
|
|
insert:
|
|
if (bypass_insert)
|
|
return BLK_STS_RESOURCE;
|
|
|
|
blk_mq_sched_insert_request(rq, false, run_queue, false);
|
|
return BLK_STS_OK;
|
|
}
|
|
|
|
static void blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq, blk_qc_t *cookie)
|
|
{
|
|
blk_status_t ret;
|
|
int srcu_idx;
|
|
|
|
might_sleep_if(hctx->flags & BLK_MQ_F_BLOCKING);
|
|
|
|
hctx_lock(hctx, &srcu_idx);
|
|
|
|
ret = __blk_mq_try_issue_directly(hctx, rq, cookie, false);
|
|
if (ret == BLK_STS_RESOURCE || ret == BLK_STS_DEV_RESOURCE)
|
|
blk_mq_sched_insert_request(rq, false, true, false);
|
|
else if (ret != BLK_STS_OK)
|
|
blk_mq_end_request(rq, ret);
|
|
|
|
hctx_unlock(hctx, srcu_idx);
|
|
}
|
|
|
|
blk_status_t blk_mq_request_issue_directly(struct request *rq)
|
|
{
|
|
blk_status_t ret;
|
|
int srcu_idx;
|
|
blk_qc_t unused_cookie;
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx;
|
|
struct blk_mq_hw_ctx *hctx = blk_mq_map_queue(rq->q, ctx->cpu);
|
|
|
|
hctx_lock(hctx, &srcu_idx);
|
|
ret = __blk_mq_try_issue_directly(hctx, rq, &unused_cookie, true);
|
|
hctx_unlock(hctx, srcu_idx);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
const int is_sync = op_is_sync(bio->bi_opf);
|
|
const int is_flush_fua = op_is_flush(bio->bi_opf);
|
|
struct blk_mq_alloc_data data = { .flags = 0 };
|
|
struct request *rq;
|
|
unsigned int request_count = 0;
|
|
struct blk_plug *plug;
|
|
struct request *same_queue_rq = NULL;
|
|
blk_qc_t cookie;
|
|
unsigned int wb_acct;
|
|
|
|
blk_queue_bounce(q, &bio);
|
|
|
|
blk_queue_split(q, &bio);
|
|
|
|
if (!bio_integrity_prep(bio))
|
|
return BLK_QC_T_NONE;
|
|
|
|
if (!is_flush_fua && !blk_queue_nomerges(q) &&
|
|
blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
|
|
return BLK_QC_T_NONE;
|
|
|
|
if (blk_mq_sched_bio_merge(q, bio))
|
|
return BLK_QC_T_NONE;
|
|
|
|
wb_acct = wbt_wait(q->rq_wb, bio, NULL);
|
|
|
|
trace_block_getrq(q, bio, bio->bi_opf);
|
|
|
|
rq = blk_mq_get_request(q, bio, bio->bi_opf, &data);
|
|
if (unlikely(!rq)) {
|
|
__wbt_done(q->rq_wb, wb_acct);
|
|
if (bio->bi_opf & REQ_NOWAIT)
|
|
bio_wouldblock_error(bio);
|
|
return BLK_QC_T_NONE;
|
|
}
|
|
|
|
wbt_track(rq, wb_acct);
|
|
|
|
cookie = request_to_qc_t(data.hctx, rq);
|
|
|
|
plug = current->plug;
|
|
if (unlikely(is_flush_fua)) {
|
|
blk_mq_put_ctx(data.ctx);
|
|
blk_mq_bio_to_request(rq, bio);
|
|
|
|
/* bypass scheduler for flush rq */
|
|
blk_insert_flush(rq);
|
|
blk_mq_run_hw_queue(data.hctx, true);
|
|
} else if (plug && q->nr_hw_queues == 1) {
|
|
struct request *last = NULL;
|
|
|
|
blk_mq_put_ctx(data.ctx);
|
|
blk_mq_bio_to_request(rq, bio);
|
|
|
|
/*
|
|
* @request_count may become stale because of schedule
|
|
* out, so check the list again.
|
|
*/
|
|
if (list_empty(&plug->mq_list))
|
|
request_count = 0;
|
|
else if (blk_queue_nomerges(q))
|
|
request_count = blk_plug_queued_count(q);
|
|
|
|
if (!request_count)
|
|
trace_block_plug(q);
|
|
else
|
|
last = list_entry_rq(plug->mq_list.prev);
|
|
|
|
if (request_count >= BLK_MAX_REQUEST_COUNT || (last &&
|
|
blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
|
|
blk_flush_plug_list(plug, false);
|
|
trace_block_plug(q);
|
|
}
|
|
|
|
list_add_tail(&rq->queuelist, &plug->mq_list);
|
|
} else if (plug && !blk_queue_nomerges(q)) {
|
|
blk_mq_bio_to_request(rq, bio);
|
|
|
|
/*
|
|
* We do limited plugging. If the bio can be merged, do that.
|
|
* Otherwise the existing request in the plug list will be
|
|
* issued. So the plug list will have one request at most
|
|
* The plug list might get flushed before this. If that happens,
|
|
* the plug list is empty, and same_queue_rq is invalid.
|
|
*/
|
|
if (list_empty(&plug->mq_list))
|
|
same_queue_rq = NULL;
|
|
if (same_queue_rq)
|
|
list_del_init(&same_queue_rq->queuelist);
|
|
list_add_tail(&rq->queuelist, &plug->mq_list);
|
|
|
|
blk_mq_put_ctx(data.ctx);
|
|
|
|
if (same_queue_rq) {
|
|
data.hctx = blk_mq_map_queue(q,
|
|
same_queue_rq->mq_ctx->cpu);
|
|
blk_mq_try_issue_directly(data.hctx, same_queue_rq,
|
|
&cookie);
|
|
}
|
|
} else if (q->nr_hw_queues > 1 && is_sync) {
|
|
blk_mq_put_ctx(data.ctx);
|
|
blk_mq_bio_to_request(rq, bio);
|
|
blk_mq_try_issue_directly(data.hctx, rq, &cookie);
|
|
} else {
|
|
blk_mq_put_ctx(data.ctx);
|
|
blk_mq_bio_to_request(rq, bio);
|
|
blk_mq_sched_insert_request(rq, false, true, true);
|
|
}
|
|
|
|
return cookie;
|
|
}
|
|
|
|
void blk_mq_free_rqs(struct blk_mq_tag_set *set, struct blk_mq_tags *tags,
|
|
unsigned int hctx_idx)
|
|
{
|
|
struct page *page;
|
|
|
|
if (tags->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;
|
|
}
|
|
}
|
|
|
|
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_init_rq_map().
|
|
*/
|
|
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);
|
|
}
|
|
|
|
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->mq_map, 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 size_t order_to_size(unsigned int order)
|
|
{
|
|
return (size_t)PAGE_SIZE << order;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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->mq_map, 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;
|
|
}
|
|
|
|
/*
|
|
* '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);
|
|
|
|
hctx = hlist_entry_safe(node, struct blk_mq_hw_ctx, cpuhp_dead);
|
|
ctx = __blk_mq_get_ctx(hctx->queue, cpu);
|
|
|
|
spin_lock(&ctx->lock);
|
|
if (!list_empty(&ctx->rq_list)) {
|
|
list_splice_init(&ctx->rq_list, &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)
|
|
{
|
|
cpuhp_state_remove_instance_nocalls(CPUHP_BLK_MQ_DEAD,
|
|
&hctx->cpuhp_dead);
|
|
}
|
|
|
|
/* 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)
|
|
{
|
|
blk_mq_debugfs_unregister_hctx(hctx);
|
|
|
|
if (blk_mq_hw_queue_mapped(hctx))
|
|
blk_mq_tag_idle(hctx);
|
|
|
|
if (set->ops->exit_request)
|
|
set->ops->exit_request(set, hctx->fq->flush_rq, hctx_idx);
|
|
|
|
blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
|
|
|
|
if (set->ops->exit_hctx)
|
|
set->ops->exit_hctx(hctx, hctx_idx);
|
|
|
|
if (hctx->flags & BLK_MQ_F_BLOCKING)
|
|
cleanup_srcu_struct(hctx->srcu);
|
|
|
|
blk_mq_remove_cpuhp(hctx);
|
|
blk_free_flush_queue(hctx->fq);
|
|
sbitmap_free(&hctx->ctx_map);
|
|
}
|
|
|
|
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_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)
|
|
{
|
|
int node;
|
|
|
|
node = hctx->numa_node;
|
|
if (node == NUMA_NO_NODE)
|
|
node = hctx->numa_node = set->numa_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_SHARED;
|
|
|
|
cpuhp_state_add_instance_nocalls(CPUHP_BLK_MQ_DEAD, &hctx->cpuhp_dead);
|
|
|
|
hctx->tags = set->tags[hctx_idx];
|
|
|
|
/*
|
|
* Allocate space for all possible cpus to avoid allocation at
|
|
* runtime
|
|
*/
|
|
hctx->ctxs = kmalloc_array_node(nr_cpu_ids, sizeof(void *),
|
|
GFP_KERNEL, node);
|
|
if (!hctx->ctxs)
|
|
goto unregister_cpu_notifier;
|
|
|
|
if (sbitmap_init_node(&hctx->ctx_map, nr_cpu_ids, ilog2(8), GFP_KERNEL,
|
|
node))
|
|
goto free_ctxs;
|
|
|
|
hctx->nr_ctx = 0;
|
|
|
|
init_waitqueue_func_entry(&hctx->dispatch_wait, blk_mq_dispatch_wake);
|
|
INIT_LIST_HEAD(&hctx->dispatch_wait.entry);
|
|
|
|
if (set->ops->init_hctx &&
|
|
set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
|
|
goto free_bitmap;
|
|
|
|
if (blk_mq_sched_init_hctx(q, hctx, hctx_idx))
|
|
goto exit_hctx;
|
|
|
|
hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
|
|
if (!hctx->fq)
|
|
goto sched_exit_hctx;
|
|
|
|
if (blk_mq_init_request(set, hctx->fq->flush_rq, hctx_idx, node))
|
|
goto free_fq;
|
|
|
|
if (hctx->flags & BLK_MQ_F_BLOCKING)
|
|
init_srcu_struct(hctx->srcu);
|
|
|
|
blk_mq_debugfs_register_hctx(q, hctx);
|
|
|
|
return 0;
|
|
|
|
free_fq:
|
|
kfree(hctx->fq);
|
|
sched_exit_hctx:
|
|
blk_mq_sched_exit_hctx(q, hctx, hctx_idx);
|
|
exit_hctx:
|
|
if (set->ops->exit_hctx)
|
|
set->ops->exit_hctx(hctx, hctx_idx);
|
|
free_bitmap:
|
|
sbitmap_free(&hctx->ctx_map);
|
|
free_ctxs:
|
|
kfree(hctx->ctxs);
|
|
unregister_cpu_notifier:
|
|
blk_mq_remove_cpuhp(hctx);
|
|
return -1;
|
|
}
|
|
|
|
static void blk_mq_init_cpu_queues(struct request_queue *q,
|
|
unsigned int nr_hw_queues)
|
|
{
|
|
unsigned int i;
|
|
|
|
for_each_possible_cpu(i) {
|
|
struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
|
|
struct blk_mq_hw_ctx *hctx;
|
|
|
|
__ctx->cpu = i;
|
|
spin_lock_init(&__ctx->lock);
|
|
INIT_LIST_HEAD(&__ctx->rq_list);
|
|
__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
|
|
*/
|
|
hctx = blk_mq_map_queue(q, i);
|
|
if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
|
|
hctx->numa_node = local_memory_node(cpu_to_node(i));
|
|
}
|
|
}
|
|
|
|
static bool __blk_mq_alloc_rq_map(struct blk_mq_tag_set *set, int hctx_idx)
|
|
{
|
|
int ret = 0;
|
|
|
|
set->tags[hctx_idx] = blk_mq_alloc_rq_map(set, hctx_idx,
|
|
set->queue_depth, set->reserved_tags);
|
|
if (!set->tags[hctx_idx])
|
|
return false;
|
|
|
|
ret = blk_mq_alloc_rqs(set, set->tags[hctx_idx], hctx_idx,
|
|
set->queue_depth);
|
|
if (!ret)
|
|
return true;
|
|
|
|
blk_mq_free_rq_map(set->tags[hctx_idx]);
|
|
set->tags[hctx_idx] = NULL;
|
|
return false;
|
|
}
|
|
|
|
static void blk_mq_free_map_and_requests(struct blk_mq_tag_set *set,
|
|
unsigned int hctx_idx)
|
|
{
|
|
if (set->tags[hctx_idx]) {
|
|
blk_mq_free_rqs(set, set->tags[hctx_idx], hctx_idx);
|
|
blk_mq_free_rq_map(set->tags[hctx_idx]);
|
|
set->tags[hctx_idx] = NULL;
|
|
}
|
|
}
|
|
|
|
static void blk_mq_map_swqueue(struct request_queue *q)
|
|
{
|
|
unsigned int i, hctx_idx;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx;
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
/*
|
|
* Avoid others reading imcomplete hctx->cpumask through sysfs
|
|
*/
|
|
mutex_lock(&q->sysfs_lock);
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
cpumask_clear(hctx->cpumask);
|
|
hctx->nr_ctx = 0;
|
|
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) {
|
|
hctx_idx = q->mq_map[i];
|
|
/* unmapped hw queue can be remapped after CPU topo changed */
|
|
if (!set->tags[hctx_idx] &&
|
|
!__blk_mq_alloc_rq_map(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
|
|
*/
|
|
q->mq_map[i] = 0;
|
|
}
|
|
|
|
ctx = per_cpu_ptr(q->queue_ctx, i);
|
|
hctx = blk_mq_map_queue(q, i);
|
|
|
|
cpumask_set_cpu(i, hctx->cpumask);
|
|
ctx->index_hw = hctx->nr_ctx;
|
|
hctx->ctxs[hctx->nr_ctx++] = ctx;
|
|
}
|
|
|
|
mutex_unlock(&q->sysfs_lock);
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
/*
|
|
* 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 && set->tags[i])
|
|
blk_mq_free_map_and_requests(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) {
|
|
if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
|
|
atomic_inc(&q->shared_hctx_restart);
|
|
hctx->flags |= BLK_MQ_F_TAG_SHARED;
|
|
} else {
|
|
if (test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
|
|
atomic_dec(&q->shared_hctx_restart);
|
|
hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
|
|
}
|
|
}
|
|
}
|
|
|
|
static void blk_mq_update_tag_set_depth(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_rcu(&q->tag_set_list);
|
|
if (list_is_singular(&set->tag_list)) {
|
|
/* just transitioned to unshared */
|
|
set->flags &= ~BLK_MQ_F_TAG_SHARED;
|
|
/* update existing queue */
|
|
blk_mq_update_tag_set_depth(set, false);
|
|
}
|
|
mutex_unlock(&set->tag_list_lock);
|
|
synchronize_rcu();
|
|
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)
|
|
{
|
|
q->tag_set = set;
|
|
|
|
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_SHARED)) {
|
|
set->flags |= BLK_MQ_F_TAG_SHARED;
|
|
/* update existing queue */
|
|
blk_mq_update_tag_set_depth(set, true);
|
|
}
|
|
if (set->flags & BLK_MQ_F_TAG_SHARED)
|
|
queue_set_hctx_shared(q, true);
|
|
list_add_tail_rcu(&q->tag_set_list, &set->tag_list);
|
|
|
|
mutex_unlock(&set->tag_list_lock);
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
unsigned int i;
|
|
|
|
/* hctx kobj stays in hctx */
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (!hctx)
|
|
continue;
|
|
kobject_put(&hctx->kobj);
|
|
}
|
|
|
|
q->mq_map = NULL;
|
|
|
|
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);
|
|
|
|
free_percpu(q->queue_ctx);
|
|
}
|
|
|
|
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
|
|
{
|
|
struct request_queue *uninit_q, *q;
|
|
|
|
uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node, NULL);
|
|
if (!uninit_q)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
q = blk_mq_init_allocated_queue(set, uninit_q);
|
|
if (IS_ERR(q))
|
|
blk_cleanup_queue(uninit_q);
|
|
|
|
return q;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_init_queue);
|
|
|
|
static int blk_mq_hw_ctx_size(struct blk_mq_tag_set *tag_set)
|
|
{
|
|
int hw_ctx_size = sizeof(struct blk_mq_hw_ctx);
|
|
|
|
BUILD_BUG_ON(ALIGN(offsetof(struct blk_mq_hw_ctx, srcu),
|
|
__alignof__(struct blk_mq_hw_ctx)) !=
|
|
sizeof(struct blk_mq_hw_ctx));
|
|
|
|
if (tag_set->flags & BLK_MQ_F_BLOCKING)
|
|
hw_ctx_size += sizeof(struct srcu_struct);
|
|
|
|
return hw_ctx_size;
|
|
}
|
|
|
|
static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
|
|
struct request_queue *q)
|
|
{
|
|
int i, j;
|
|
struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
|
|
|
|
blk_mq_sysfs_unregister(q);
|
|
|
|
/* protect against switching io scheduler */
|
|
mutex_lock(&q->sysfs_lock);
|
|
for (i = 0; i < set->nr_hw_queues; i++) {
|
|
int node;
|
|
|
|
if (hctxs[i])
|
|
continue;
|
|
|
|
node = blk_mq_hw_queue_to_node(q->mq_map, i);
|
|
hctxs[i] = kzalloc_node(blk_mq_hw_ctx_size(set),
|
|
GFP_KERNEL, node);
|
|
if (!hctxs[i])
|
|
break;
|
|
|
|
if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
|
|
node)) {
|
|
kfree(hctxs[i]);
|
|
hctxs[i] = NULL;
|
|
break;
|
|
}
|
|
|
|
atomic_set(&hctxs[i]->nr_active, 0);
|
|
hctxs[i]->numa_node = node;
|
|
hctxs[i]->queue_num = i;
|
|
|
|
if (blk_mq_init_hctx(q, set, hctxs[i], i)) {
|
|
free_cpumask_var(hctxs[i]->cpumask);
|
|
kfree(hctxs[i]);
|
|
hctxs[i] = NULL;
|
|
break;
|
|
}
|
|
blk_mq_hctx_kobj_init(hctxs[i]);
|
|
}
|
|
for (j = i; j < q->nr_hw_queues; j++) {
|
|
struct blk_mq_hw_ctx *hctx = hctxs[j];
|
|
|
|
if (hctx) {
|
|
if (hctx->tags)
|
|
blk_mq_free_map_and_requests(set, j);
|
|
blk_mq_exit_hctx(q, set, hctx, j);
|
|
kobject_put(&hctx->kobj);
|
|
hctxs[j] = NULL;
|
|
|
|
}
|
|
}
|
|
q->nr_hw_queues = i;
|
|
mutex_unlock(&q->sysfs_lock);
|
|
blk_mq_sysfs_register(q);
|
|
}
|
|
|
|
struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
|
|
struct request_queue *q)
|
|
{
|
|
/* 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;
|
|
|
|
q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
|
|
if (!q->queue_ctx)
|
|
goto err_exit;
|
|
|
|
/* init q->mq_kobj and sw queues' kobjects */
|
|
blk_mq_sysfs_init(q);
|
|
|
|
q->queue_hw_ctx = kcalloc_node(nr_cpu_ids, sizeof(*(q->queue_hw_ctx)),
|
|
GFP_KERNEL, set->numa_node);
|
|
if (!q->queue_hw_ctx)
|
|
goto err_percpu;
|
|
|
|
q->mq_map = set->mq_map;
|
|
|
|
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->nr_queues = nr_cpu_ids;
|
|
|
|
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
|
|
|
|
if (!(set->flags & BLK_MQ_F_SG_MERGE))
|
|
queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
|
|
|
|
q->sg_reserved_size = INT_MAX;
|
|
|
|
INIT_DELAYED_WORK(&q->requeue_work, blk_mq_requeue_work);
|
|
INIT_LIST_HEAD(&q->requeue_list);
|
|
spin_lock_init(&q->requeue_lock);
|
|
|
|
blk_queue_make_request(q, blk_mq_make_request);
|
|
if (q->mq_ops->poll)
|
|
q->poll_fn = blk_mq_poll;
|
|
|
|
/*
|
|
* Do this after blk_queue_make_request() overrides it...
|
|
*/
|
|
q->nr_requests = set->queue_depth;
|
|
|
|
/*
|
|
* Default to classic polling
|
|
*/
|
|
q->poll_nsec = -1;
|
|
|
|
if (set->ops->complete)
|
|
blk_queue_softirq_done(q, set->ops->complete);
|
|
|
|
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
|
|
blk_mq_add_queue_tag_set(set, q);
|
|
blk_mq_map_swqueue(q);
|
|
|
|
if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
|
|
int ret;
|
|
|
|
ret = elevator_init_mq(q);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
}
|
|
|
|
return q;
|
|
|
|
err_hctxs:
|
|
kfree(q->queue_hw_ctx);
|
|
err_percpu:
|
|
free_percpu(q->queue_ctx);
|
|
err_exit:
|
|
q->mq_ops = NULL;
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_init_allocated_queue);
|
|
|
|
void blk_mq_free_queue(struct request_queue *q)
|
|
{
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
blk_mq_del_queue_tag_set(q);
|
|
blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
|
|
}
|
|
|
|
/* Basically redo blk_mq_init_queue with queue frozen */
|
|
static void blk_mq_queue_reinit(struct request_queue *q)
|
|
{
|
|
WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
|
|
|
|
blk_mq_debugfs_unregister_hctxs(q);
|
|
blk_mq_sysfs_unregister(q);
|
|
|
|
/*
|
|
* redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
|
|
* we should change hctx numa_node according to the new topology (this
|
|
* involves freeing and re-allocating memory, worth doing?)
|
|
*/
|
|
blk_mq_map_swqueue(q);
|
|
|
|
blk_mq_sysfs_register(q);
|
|
blk_mq_debugfs_register_hctxs(q);
|
|
}
|
|
|
|
static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < set->nr_hw_queues; i++)
|
|
if (!__blk_mq_alloc_rq_map(set, i))
|
|
goto out_unwind;
|
|
|
|
return 0;
|
|
|
|
out_unwind:
|
|
while (--i >= 0)
|
|
blk_mq_free_rq_map(set->tags[i]);
|
|
|
|
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_rq_maps(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)
|
|
{
|
|
if (set->ops->map_queues) {
|
|
int cpu;
|
|
/*
|
|
* 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->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_each_possible_cpu(cpu)
|
|
set->mq_map[cpu] = 0;
|
|
|
|
return set->ops->map_queues(set);
|
|
} else
|
|
return blk_mq_map_queues(set);
|
|
}
|
|
|
|
/*
|
|
* 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 if it 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 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 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->queue_depth = min(64U, set->queue_depth);
|
|
}
|
|
/*
|
|
* There is no use for more h/w queues than cpus.
|
|
*/
|
|
if (set->nr_hw_queues > nr_cpu_ids)
|
|
set->nr_hw_queues = nr_cpu_ids;
|
|
|
|
set->tags = kcalloc_node(nr_cpu_ids, sizeof(struct blk_mq_tags *),
|
|
GFP_KERNEL, set->numa_node);
|
|
if (!set->tags)
|
|
return -ENOMEM;
|
|
|
|
ret = -ENOMEM;
|
|
set->mq_map = kcalloc_node(nr_cpu_ids, sizeof(*set->mq_map),
|
|
GFP_KERNEL, set->numa_node);
|
|
if (!set->mq_map)
|
|
goto out_free_tags;
|
|
|
|
ret = blk_mq_update_queue_map(set);
|
|
if (ret)
|
|
goto out_free_mq_map;
|
|
|
|
ret = blk_mq_alloc_rq_maps(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:
|
|
kfree(set->mq_map);
|
|
set->mq_map = NULL;
|
|
out_free_tags:
|
|
kfree(set->tags);
|
|
set->tags = NULL;
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_alloc_tag_set);
|
|
|
|
void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < nr_cpu_ids; i++)
|
|
blk_mq_free_map_and_requests(set, i);
|
|
|
|
kfree(set->mq_map);
|
|
set->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;
|
|
|
|
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->tags, nr,
|
|
false);
|
|
} else {
|
|
ret = blk_mq_tag_update_depth(hctx, &hctx->sched_tags,
|
|
nr, true);
|
|
}
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
if (!ret)
|
|
q->nr_requests = nr;
|
|
|
|
blk_mq_unquiesce_queue(q);
|
|
blk_mq_unfreeze_queue(q);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
|
|
int nr_hw_queues)
|
|
{
|
|
struct request_queue *q;
|
|
|
|
lockdep_assert_held(&set->tag_list_lock);
|
|
|
|
if (nr_hw_queues > nr_cpu_ids)
|
|
nr_hw_queues = nr_cpu_ids;
|
|
if (nr_hw_queues < 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);
|
|
|
|
set->nr_hw_queues = nr_hw_queues;
|
|
blk_mq_update_queue_map(set);
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list) {
|
|
blk_mq_realloc_hw_ctxs(set, q);
|
|
blk_mq_queue_reinit(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 (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
|
|
blk_queue_flag_test_and_set(QUEUE_FLAG_POLL_STATS, q))
|
|
return true;
|
|
blk_stat_add_callback(q, q->poll_cb);
|
|
return false;
|
|
}
|
|
|
|
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 (!test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags) ||
|
|
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 blk_mq_hw_ctx *hctx,
|
|
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_sleep(struct request_queue *q,
|
|
struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq)
|
|
{
|
|
struct hrtimer_sleeper hs;
|
|
enum hrtimer_mode mode;
|
|
unsigned int nsecs;
|
|
ktime_t kt;
|
|
|
|
if (rq->rq_flags & RQF_MQ_POLL_SLEPT)
|
|
return false;
|
|
|
|
/*
|
|
* poll_nsec can be:
|
|
*
|
|
* -1: don't ever hybrid sleep
|
|
* 0: use half of prev avg
|
|
* >0: use this specific value
|
|
*/
|
|
if (q->poll_nsec == -1)
|
|
return false;
|
|
else if (q->poll_nsec > 0)
|
|
nsecs = q->poll_nsec;
|
|
else
|
|
nsecs = blk_mq_poll_nsecs(q, hctx, 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_on_stack(&hs.timer, CLOCK_MONOTONIC, mode);
|
|
hrtimer_set_expires(&hs.timer, kt);
|
|
|
|
hrtimer_init_sleeper(&hs, current);
|
|
do {
|
|
if (blk_mq_rq_state(rq) == MQ_RQ_COMPLETE)
|
|
break;
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
|
hrtimer_start_expires(&hs.timer, 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);
|
|
return true;
|
|
}
|
|
|
|
static bool __blk_mq_poll(struct blk_mq_hw_ctx *hctx, struct request *rq)
|
|
{
|
|
struct request_queue *q = hctx->queue;
|
|
long state;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
if (blk_mq_poll_hybrid_sleep(q, hctx, rq))
|
|
return true;
|
|
|
|
hctx->poll_considered++;
|
|
|
|
state = current->state;
|
|
while (!need_resched()) {
|
|
int ret;
|
|
|
|
hctx->poll_invoked++;
|
|
|
|
ret = q->mq_ops->poll(hctx, rq->tag);
|
|
if (ret > 0) {
|
|
hctx->poll_success++;
|
|
set_current_state(TASK_RUNNING);
|
|
return true;
|
|
}
|
|
|
|
if (signal_pending_state(state, current))
|
|
set_current_state(TASK_RUNNING);
|
|
|
|
if (current->state == TASK_RUNNING)
|
|
return true;
|
|
if (ret < 0)
|
|
break;
|
|
cpu_relax();
|
|
}
|
|
|
|
__set_current_state(TASK_RUNNING);
|
|
return false;
|
|
}
|
|
|
|
static bool blk_mq_poll(struct request_queue *q, blk_qc_t cookie)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct request *rq;
|
|
|
|
if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
|
|
return false;
|
|
|
|
hctx = q->queue_hw_ctx[blk_qc_t_to_queue_num(cookie)];
|
|
if (!blk_qc_t_is_internal(cookie))
|
|
rq = blk_mq_tag_to_rq(hctx->tags, blk_qc_t_to_tag(cookie));
|
|
else {
|
|
rq = blk_mq_tag_to_rq(hctx->sched_tags, blk_qc_t_to_tag(cookie));
|
|
/*
|
|
* With scheduling, if the request has completed, we'll
|
|
* get a NULL return here, as we clear the sched tag when
|
|
* that happens. The request still remains valid, like always,
|
|
* so we should be safe with just the NULL check.
|
|
*/
|
|
if (!rq)
|
|
return false;
|
|
}
|
|
|
|
return __blk_mq_poll(hctx, rq);
|
|
}
|
|
|
|
static int __init blk_mq_init(void)
|
|
{
|
|
cpuhp_setup_state_multi(CPUHP_BLK_MQ_DEAD, "block/mq:dead", NULL,
|
|
blk_mq_hctx_notify_dead);
|
|
return 0;
|
|
}
|
|
subsys_initcall(blk_mq_init);
|