![Linus Torvalds](/assets/img/avatar_default.png)
Pull core block IO changes from Jens Axboe: "This contains: - A series from Christoph that cleans up and refactors various parts of the REQ_BLOCK_PC handling. Contributions in that series from Dongsu Park and Kent Overstreet as well. - CFQ: - A bug fix for cfq for realtime IO scheduling from Jeff Moyer. - A stable patch fixing a potential crash in CFQ in OOM situations. From Konstantin Khlebnikov. - blk-mq: - Add support for tag allocation policies, from Shaohua. This is a prep patch enabling libata (and other SCSI parts) to use the blk-mq tagging, instead of rolling their own. - Various little tweaks from Keith and Mike, in preparation for DM blk-mq support. - Minor little fixes or tweaks from me. - A double free error fix from Tony Battersby. - The partition 4k issue fixes from Matthew and Boaz. - Add support for zero+unprovision for blkdev_issue_zeroout() from Martin" * 'for-3.20/core' of git://git.kernel.dk/linux-block: (27 commits) block: remove unused function blk_bio_map_sg block: handle the null_mapped flag correctly in blk_rq_map_user_iov blk-mq: fix double-free in error path block: prevent request-to-request merging with gaps if not allowed blk-mq: make blk_mq_run_queues() static dm: fix multipath regression due to initializing wrong request cfq-iosched: handle failure of cfq group allocation block: Quiesce zeroout wrapper block: rewrite and split __bio_copy_iov() block: merge __bio_map_user_iov into bio_map_user_iov block: merge __bio_map_kern into bio_map_kern block: pass iov_iter to the BLOCK_PC mapping functions block: add a helper to free bio bounce buffer pages block: use blk_rq_map_user_iov to implement blk_rq_map_user block: simplify bio_map_kern block: mark blk-mq devices as stackable block: keep established cmd_flags when cloning into a blk-mq request block: add blk-mq support to blk_insert_cloned_request() block: require blk_rq_prep_clone() be given an initialized clone request blk-mq: add tag allocation policy ...
2258 lines
52 KiB
C
2258 lines
52 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/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/delay.h>
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#include <linux/crash_dump.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-tag.h"
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static DEFINE_MUTEX(all_q_mutex);
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static LIST_HEAD(all_q_list);
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static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);
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static void blk_mq_run_queues(struct request_queue *q);
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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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unsigned int i;
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for (i = 0; i < hctx->ctx_map.map_size; i++)
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if (hctx->ctx_map.map[i].word)
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return true;
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return false;
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}
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static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx,
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struct blk_mq_ctx *ctx)
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{
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return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word];
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}
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#define CTX_TO_BIT(hctx, ctx) \
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((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1))
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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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struct blk_align_bitmap *bm = get_bm(hctx, ctx);
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if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word))
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set_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
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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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struct blk_align_bitmap *bm = get_bm(hctx, ctx);
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clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
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}
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static int blk_mq_queue_enter(struct request_queue *q)
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{
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while (true) {
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int ret;
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if (percpu_ref_tryget_live(&q->mq_usage_counter))
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return 0;
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ret = wait_event_interruptible(q->mq_freeze_wq,
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!q->mq_freeze_depth || blk_queue_dying(q));
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if (blk_queue_dying(q))
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return -ENODEV;
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if (ret)
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return ret;
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}
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}
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static void blk_mq_queue_exit(struct request_queue *q)
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{
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percpu_ref_put(&q->mq_usage_counter);
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}
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static void blk_mq_usage_counter_release(struct percpu_ref *ref)
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{
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struct request_queue *q =
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container_of(ref, struct request_queue, mq_usage_counter);
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wake_up_all(&q->mq_freeze_wq);
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}
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void blk_mq_freeze_queue_start(struct request_queue *q)
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{
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bool freeze;
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spin_lock_irq(q->queue_lock);
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freeze = !q->mq_freeze_depth++;
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spin_unlock_irq(q->queue_lock);
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if (freeze) {
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percpu_ref_kill(&q->mq_usage_counter);
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blk_mq_run_queues(q);
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}
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}
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EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
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static 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->mq_usage_counter));
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}
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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_mq_freeze_queue(struct request_queue *q)
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{
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blk_mq_freeze_queue_start(q);
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blk_mq_freeze_queue_wait(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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bool wake;
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spin_lock_irq(q->queue_lock);
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wake = !--q->mq_freeze_depth;
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WARN_ON_ONCE(q->mq_freeze_depth < 0);
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spin_unlock_irq(q->queue_lock);
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if (wake) {
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percpu_ref_reinit(&q->mq_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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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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* If we are called because the queue has now been marked as
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* dying, we need to ensure that processes currently waiting on
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* the queue are notified as well.
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*/
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wake_up_all(&q->mq_freeze_wq);
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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 void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
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struct request *rq, unsigned int rw_flags)
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{
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if (blk_queue_io_stat(q))
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rw_flags |= REQ_IO_STAT;
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INIT_LIST_HEAD(&rq->queuelist);
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/* csd/requeue_work/fifo_time is initialized before use */
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rq->q = q;
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rq->mq_ctx = ctx;
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rq->cmd_flags |= rw_flags;
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/* do not touch atomic flags, it needs atomic ops against the timer */
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rq->cpu = -1;
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INIT_HLIST_NODE(&rq->hash);
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RB_CLEAR_NODE(&rq->rb_node);
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rq->rq_disk = NULL;
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rq->part = NULL;
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rq->start_time = jiffies;
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#ifdef CONFIG_BLK_CGROUP
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rq->rl = NULL;
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set_start_time_ns(rq);
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rq->io_start_time_ns = 0;
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#endif
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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->errors = 0;
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rq->cmd = rq->__cmd;
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rq->extra_len = 0;
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rq->sense_len = 0;
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rq->resid_len = 0;
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rq->sense = NULL;
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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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ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
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}
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static struct request *
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__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw)
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{
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struct request *rq;
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unsigned int tag;
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tag = blk_mq_get_tag(data);
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if (tag != BLK_MQ_TAG_FAIL) {
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rq = data->hctx->tags->rqs[tag];
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if (blk_mq_tag_busy(data->hctx)) {
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rq->cmd_flags = REQ_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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blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw);
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return rq;
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}
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return NULL;
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}
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struct request *blk_mq_alloc_request(struct request_queue *q, int rw, gfp_t gfp,
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bool reserved)
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{
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struct blk_mq_ctx *ctx;
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struct blk_mq_hw_ctx *hctx;
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struct request *rq;
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struct blk_mq_alloc_data alloc_data;
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int ret;
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ret = blk_mq_queue_enter(q);
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if (ret)
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return ERR_PTR(ret);
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ctx = blk_mq_get_ctx(q);
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hctx = q->mq_ops->map_queue(q, ctx->cpu);
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blk_mq_set_alloc_data(&alloc_data, q, gfp & ~__GFP_WAIT,
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reserved, ctx, hctx);
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rq = __blk_mq_alloc_request(&alloc_data, rw);
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if (!rq && (gfp & __GFP_WAIT)) {
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__blk_mq_run_hw_queue(hctx);
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blk_mq_put_ctx(ctx);
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ctx = blk_mq_get_ctx(q);
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hctx = q->mq_ops->map_queue(q, ctx->cpu);
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blk_mq_set_alloc_data(&alloc_data, q, gfp, reserved, ctx,
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hctx);
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rq = __blk_mq_alloc_request(&alloc_data, rw);
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ctx = alloc_data.ctx;
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}
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blk_mq_put_ctx(ctx);
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if (!rq) {
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blk_mq_queue_exit(q);
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return ERR_PTR(-EWOULDBLOCK);
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}
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return rq;
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}
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EXPORT_SYMBOL(blk_mq_alloc_request);
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static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
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struct blk_mq_ctx *ctx, struct request *rq)
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{
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const int tag = rq->tag;
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struct request_queue *q = rq->q;
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if (rq->cmd_flags & REQ_MQ_INFLIGHT)
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atomic_dec(&hctx->nr_active);
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rq->cmd_flags = 0;
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clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
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blk_mq_put_tag(hctx, tag, &ctx->last_tag);
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blk_mq_queue_exit(q);
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}
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void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
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{
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struct blk_mq_ctx *ctx = rq->mq_ctx;
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ctx->rq_completed[rq_is_sync(rq)]++;
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__blk_mq_free_request(hctx, ctx, rq);
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}
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EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request);
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void blk_mq_free_request(struct request *rq)
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{
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struct blk_mq_hw_ctx *hctx;
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struct request_queue *q = rq->q;
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hctx = q->mq_ops->map_queue(q, rq->mq_ctx->cpu);
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blk_mq_free_hctx_request(hctx, rq);
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}
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EXPORT_SYMBOL_GPL(blk_mq_free_request);
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inline void __blk_mq_end_request(struct request *rq, int error)
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{
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blk_account_io_done(rq);
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if (rq->end_io) {
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rq->end_io(rq, error);
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} else {
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if (unlikely(blk_bidi_rq(rq)))
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blk_mq_free_request(rq->next_rq);
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blk_mq_free_request(rq);
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}
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}
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EXPORT_SYMBOL(__blk_mq_end_request);
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void blk_mq_end_request(struct request *rq, int error)
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{
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if (blk_update_request(rq, error, blk_rq_bytes(rq)))
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BUG();
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__blk_mq_end_request(rq, error);
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}
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EXPORT_SYMBOL(blk_mq_end_request);
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static void __blk_mq_complete_request_remote(void *data)
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{
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struct request *rq = data;
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rq->q->softirq_done_fn(rq);
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}
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static void blk_mq_ipi_complete_request(struct request *rq)
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{
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struct blk_mq_ctx *ctx = rq->mq_ctx;
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bool shared = false;
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int cpu;
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if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
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rq->q->softirq_done_fn(rq);
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return;
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}
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cpu = get_cpu();
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if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
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shared = cpus_share_cache(cpu, ctx->cpu);
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if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
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rq->csd.func = __blk_mq_complete_request_remote;
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rq->csd.info = rq;
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rq->csd.flags = 0;
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smp_call_function_single_async(ctx->cpu, &rq->csd);
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} else {
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rq->q->softirq_done_fn(rq);
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}
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put_cpu();
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}
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void __blk_mq_complete_request(struct request *rq)
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{
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struct request_queue *q = rq->q;
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if (!q->softirq_done_fn)
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blk_mq_end_request(rq, rq->errors);
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else
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blk_mq_ipi_complete_request(rq);
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}
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/**
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* blk_mq_complete_request - end I/O on a request
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* @rq: the request being processed
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*
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* Description:
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* Ends all I/O on a request. It does not handle partial completions.
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* The actual completion happens out-of-order, through a IPI handler.
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**/
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void blk_mq_complete_request(struct request *rq)
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{
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struct request_queue *q = rq->q;
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if (unlikely(blk_should_fake_timeout(q)))
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return;
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if (!blk_mark_rq_complete(rq))
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__blk_mq_complete_request(rq);
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}
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EXPORT_SYMBOL(blk_mq_complete_request);
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int blk_mq_request_started(struct request *rq)
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{
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return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
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}
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EXPORT_SYMBOL_GPL(blk_mq_request_started);
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void blk_mq_start_request(struct request *rq)
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{
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struct request_queue *q = rq->q;
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trace_block_rq_issue(q, rq);
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rq->resid_len = blk_rq_bytes(rq);
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if (unlikely(blk_bidi_rq(rq)))
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rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq);
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blk_add_timer(rq);
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/*
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* Ensure that ->deadline is visible before set the started
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* flag and clear the completed flag.
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*/
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smp_mb__before_atomic();
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/*
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* Mark us as started and clear complete. Complete might have been
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* set if requeue raced with timeout, which then marked it as
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* complete. So be sure to clear complete again when we start
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* the request, otherwise we'll ignore the completion event.
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*/
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if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
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set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
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if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags))
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clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
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if (q->dma_drain_size && blk_rq_bytes(rq)) {
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/*
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* Make sure space for the drain appears. We know we can do
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* this because max_hw_segments has been adjusted to be one
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* fewer than the device can handle.
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*/
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rq->nr_phys_segments++;
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}
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}
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EXPORT_SYMBOL(blk_mq_start_request);
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static void __blk_mq_requeue_request(struct request *rq)
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{
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struct request_queue *q = rq->q;
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trace_block_rq_requeue(q, rq);
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if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
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if (q->dma_drain_size && blk_rq_bytes(rq))
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rq->nr_phys_segments--;
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}
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}
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|
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void blk_mq_requeue_request(struct request *rq)
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{
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__blk_mq_requeue_request(rq);
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BUG_ON(blk_queued_rq(rq));
|
|
blk_mq_add_to_requeue_list(rq, true);
|
|
}
|
|
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);
|
|
LIST_HEAD(rq_list);
|
|
struct request *rq, *next;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&q->requeue_lock, flags);
|
|
list_splice_init(&q->requeue_list, &rq_list);
|
|
spin_unlock_irqrestore(&q->requeue_lock, flags);
|
|
|
|
list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
|
|
if (!(rq->cmd_flags & REQ_SOFTBARRIER))
|
|
continue;
|
|
|
|
rq->cmd_flags &= ~REQ_SOFTBARRIER;
|
|
list_del_init(&rq->queuelist);
|
|
blk_mq_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_insert_request(rq, false, false, false);
|
|
}
|
|
|
|
/*
|
|
* Use the start variant of queue running here, so that running
|
|
* the requeue work will kick stopped queues.
|
|
*/
|
|
blk_mq_start_hw_queues(q);
|
|
}
|
|
|
|
void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
|
|
{
|
|
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 insertation from the workqueue.
|
|
*/
|
|
BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER);
|
|
|
|
spin_lock_irqsave(&q->requeue_lock, flags);
|
|
if (at_head) {
|
|
rq->cmd_flags |= REQ_SOFTBARRIER;
|
|
list_add(&rq->queuelist, &q->requeue_list);
|
|
} else {
|
|
list_add_tail(&rq->queuelist, &q->requeue_list);
|
|
}
|
|
spin_unlock_irqrestore(&q->requeue_lock, flags);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
|
|
|
|
void blk_mq_cancel_requeue_work(struct request_queue *q)
|
|
{
|
|
cancel_work_sync(&q->requeue_work);
|
|
}
|
|
EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work);
|
|
|
|
void blk_mq_kick_requeue_list(struct request_queue *q)
|
|
{
|
|
kblockd_schedule_work(&q->requeue_work);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_kick_requeue_list);
|
|
|
|
void blk_mq_abort_requeue_list(struct request_queue *q)
|
|
{
|
|
unsigned long flags;
|
|
LIST_HEAD(rq_list);
|
|
|
|
spin_lock_irqsave(&q->requeue_lock, flags);
|
|
list_splice_init(&q->requeue_list, &rq_list);
|
|
spin_unlock_irqrestore(&q->requeue_lock, flags);
|
|
|
|
while (!list_empty(&rq_list)) {
|
|
struct request *rq;
|
|
|
|
rq = list_first_entry(&rq_list, struct request, queuelist);
|
|
list_del_init(&rq->queuelist);
|
|
rq->errors = -EIO;
|
|
blk_mq_end_request(rq, rq->errors);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_abort_requeue_list);
|
|
|
|
static inline bool is_flush_request(struct request *rq,
|
|
struct blk_flush_queue *fq, unsigned int tag)
|
|
{
|
|
return ((rq->cmd_flags & REQ_FLUSH_SEQ) &&
|
|
fq->flush_rq->tag == tag);
|
|
}
|
|
|
|
struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
|
|
{
|
|
struct request *rq = tags->rqs[tag];
|
|
/* mq_ctx of flush rq is always cloned from the corresponding req */
|
|
struct blk_flush_queue *fq = blk_get_flush_queue(rq->q, rq->mq_ctx);
|
|
|
|
if (!is_flush_request(rq, fq, tag))
|
|
return rq;
|
|
|
|
return fq->flush_rq;
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_tag_to_rq);
|
|
|
|
struct blk_mq_timeout_data {
|
|
unsigned long next;
|
|
unsigned int next_set;
|
|
};
|
|
|
|
void blk_mq_rq_timed_out(struct request *req, bool reserved)
|
|
{
|
|
struct blk_mq_ops *ops = req->q->mq_ops;
|
|
enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
|
|
|
|
/*
|
|
* We know that complete is set at this point. If STARTED isn't set
|
|
* anymore, then the request isn't active and the "timeout" should
|
|
* just be ignored. This can happen due to the bitflag ordering.
|
|
* Timeout first checks if STARTED is set, and if it is, assumes
|
|
* the request is active. But if we race with completion, then
|
|
* we both flags will get cleared. So check here again, and ignore
|
|
* a timeout event with a request that isn't active.
|
|
*/
|
|
if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
|
|
return;
|
|
|
|
if (ops->timeout)
|
|
ret = ops->timeout(req, reserved);
|
|
|
|
switch (ret) {
|
|
case BLK_EH_HANDLED:
|
|
__blk_mq_complete_request(req);
|
|
break;
|
|
case BLK_EH_RESET_TIMER:
|
|
blk_add_timer(req);
|
|
blk_clear_rq_complete(req);
|
|
break;
|
|
case BLK_EH_NOT_HANDLED:
|
|
break;
|
|
default:
|
|
printk(KERN_ERR "block: bad eh return: %d\n", ret);
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
|
|
struct request *rq, void *priv, bool reserved)
|
|
{
|
|
struct blk_mq_timeout_data *data = priv;
|
|
|
|
if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
|
|
/*
|
|
* If a request wasn't started before the queue was
|
|
* marked dying, kill it here or it'll go unnoticed.
|
|
*/
|
|
if (unlikely(blk_queue_dying(rq->q))) {
|
|
rq->errors = -EIO;
|
|
blk_mq_complete_request(rq);
|
|
}
|
|
return;
|
|
}
|
|
if (rq->cmd_flags & REQ_NO_TIMEOUT)
|
|
return;
|
|
|
|
if (time_after_eq(jiffies, rq->deadline)) {
|
|
if (!blk_mark_rq_complete(rq))
|
|
blk_mq_rq_timed_out(rq, reserved);
|
|
} else if (!data->next_set || time_after(data->next, rq->deadline)) {
|
|
data->next = rq->deadline;
|
|
data->next_set = 1;
|
|
}
|
|
}
|
|
|
|
static void blk_mq_rq_timer(unsigned long priv)
|
|
{
|
|
struct request_queue *q = (struct request_queue *)priv;
|
|
struct blk_mq_timeout_data data = {
|
|
.next = 0,
|
|
.next_set = 0,
|
|
};
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
/*
|
|
* If not software queues are currently mapped to this
|
|
* hardware queue, there's nothing to check
|
|
*/
|
|
if (!blk_mq_hw_queue_mapped(hctx))
|
|
continue;
|
|
|
|
blk_mq_tag_busy_iter(hctx, blk_mq_check_expired, &data);
|
|
}
|
|
|
|
if (data.next_set) {
|
|
data.next = blk_rq_timeout(round_jiffies_up(data.next));
|
|
mod_timer(&q->timeout, data.next);
|
|
} else {
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
blk_mq_tag_idle(hctx);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Reverse check our software queue for entries that we could potentially
|
|
* merge with. Currently includes a hand-wavy stop count of 8, to not spend
|
|
* too much time checking for merges.
|
|
*/
|
|
static bool blk_mq_attempt_merge(struct request_queue *q,
|
|
struct blk_mq_ctx *ctx, struct bio *bio)
|
|
{
|
|
struct request *rq;
|
|
int checked = 8;
|
|
|
|
list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
|
|
int el_ret;
|
|
|
|
if (!checked--)
|
|
break;
|
|
|
|
if (!blk_rq_merge_ok(rq, bio))
|
|
continue;
|
|
|
|
el_ret = blk_try_merge(rq, bio);
|
|
if (el_ret == ELEVATOR_BACK_MERGE) {
|
|
if (bio_attempt_back_merge(q, rq, bio)) {
|
|
ctx->rq_merged++;
|
|
return true;
|
|
}
|
|
break;
|
|
} else if (el_ret == ELEVATOR_FRONT_MERGE) {
|
|
if (bio_attempt_front_merge(q, rq, bio)) {
|
|
ctx->rq_merged++;
|
|
return true;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/*
|
|
* Process software queues that have been marked busy, splicing them
|
|
* to the for-dispatch
|
|
*/
|
|
static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
|
|
{
|
|
struct blk_mq_ctx *ctx;
|
|
int i;
|
|
|
|
for (i = 0; i < hctx->ctx_map.map_size; i++) {
|
|
struct blk_align_bitmap *bm = &hctx->ctx_map.map[i];
|
|
unsigned int off, bit;
|
|
|
|
if (!bm->word)
|
|
continue;
|
|
|
|
bit = 0;
|
|
off = i * hctx->ctx_map.bits_per_word;
|
|
do {
|
|
bit = find_next_bit(&bm->word, bm->depth, bit);
|
|
if (bit >= bm->depth)
|
|
break;
|
|
|
|
ctx = hctx->ctxs[bit + off];
|
|
clear_bit(bit, &bm->word);
|
|
spin_lock(&ctx->lock);
|
|
list_splice_tail_init(&ctx->rq_list, list);
|
|
spin_unlock(&ctx->lock);
|
|
|
|
bit++;
|
|
} while (1);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Run this hardware queue, pulling any software queues mapped to it in.
|
|
* Note that this function currently has various problems around ordering
|
|
* of IO. In particular, we'd like FIFO behaviour on handling existing
|
|
* items on the hctx->dispatch list. Ignore that for now.
|
|
*/
|
|
static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
struct request_queue *q = hctx->queue;
|
|
struct request *rq;
|
|
LIST_HEAD(rq_list);
|
|
LIST_HEAD(driver_list);
|
|
struct list_head *dptr;
|
|
int queued;
|
|
|
|
WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask));
|
|
|
|
if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
|
|
return;
|
|
|
|
hctx->run++;
|
|
|
|
/*
|
|
* Touch any software queue that has pending entries.
|
|
*/
|
|
flush_busy_ctxs(hctx, &rq_list);
|
|
|
|
/*
|
|
* If we have previous entries on our dispatch list, grab them
|
|
* and stuff them at the front for more fair dispatch.
|
|
*/
|
|
if (!list_empty_careful(&hctx->dispatch)) {
|
|
spin_lock(&hctx->lock);
|
|
if (!list_empty(&hctx->dispatch))
|
|
list_splice_init(&hctx->dispatch, &rq_list);
|
|
spin_unlock(&hctx->lock);
|
|
}
|
|
|
|
/*
|
|
* Start off with dptr being NULL, so we start the first request
|
|
* immediately, even if we have more pending.
|
|
*/
|
|
dptr = NULL;
|
|
|
|
/*
|
|
* Now process all the entries, sending them to the driver.
|
|
*/
|
|
queued = 0;
|
|
while (!list_empty(&rq_list)) {
|
|
struct blk_mq_queue_data bd;
|
|
int ret;
|
|
|
|
rq = list_first_entry(&rq_list, struct request, queuelist);
|
|
list_del_init(&rq->queuelist);
|
|
|
|
bd.rq = rq;
|
|
bd.list = dptr;
|
|
bd.last = list_empty(&rq_list);
|
|
|
|
ret = q->mq_ops->queue_rq(hctx, &bd);
|
|
switch (ret) {
|
|
case BLK_MQ_RQ_QUEUE_OK:
|
|
queued++;
|
|
continue;
|
|
case BLK_MQ_RQ_QUEUE_BUSY:
|
|
list_add(&rq->queuelist, &rq_list);
|
|
__blk_mq_requeue_request(rq);
|
|
break;
|
|
default:
|
|
pr_err("blk-mq: bad return on queue: %d\n", ret);
|
|
case BLK_MQ_RQ_QUEUE_ERROR:
|
|
rq->errors = -EIO;
|
|
blk_mq_end_request(rq, rq->errors);
|
|
break;
|
|
}
|
|
|
|
if (ret == BLK_MQ_RQ_QUEUE_BUSY)
|
|
break;
|
|
|
|
/*
|
|
* We've done the first request. If we have more than 1
|
|
* left in the list, set dptr to defer issue.
|
|
*/
|
|
if (!dptr && rq_list.next != rq_list.prev)
|
|
dptr = &driver_list;
|
|
}
|
|
|
|
if (!queued)
|
|
hctx->dispatched[0]++;
|
|
else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
|
|
hctx->dispatched[ilog2(queued) + 1]++;
|
|
|
|
/*
|
|
* Any items that need requeuing? Stuff them into hctx->dispatch,
|
|
* that is where we will continue on next queue run.
|
|
*/
|
|
if (!list_empty(&rq_list)) {
|
|
spin_lock(&hctx->lock);
|
|
list_splice(&rq_list, &hctx->dispatch);
|
|
spin_unlock(&hctx->lock);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
if (hctx->queue->nr_hw_queues == 1)
|
|
return WORK_CPU_UNBOUND;
|
|
|
|
if (--hctx->next_cpu_batch <= 0) {
|
|
int cpu = hctx->next_cpu, next_cpu;
|
|
|
|
next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
|
|
if (next_cpu >= nr_cpu_ids)
|
|
next_cpu = cpumask_first(hctx->cpumask);
|
|
|
|
hctx->next_cpu = next_cpu;
|
|
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
|
|
|
|
return cpu;
|
|
}
|
|
|
|
return hctx->next_cpu;
|
|
}
|
|
|
|
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
|
|
{
|
|
if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) ||
|
|
!blk_mq_hw_queue_mapped(hctx)))
|
|
return;
|
|
|
|
if (!async) {
|
|
int cpu = get_cpu();
|
|
if (cpumask_test_cpu(cpu, hctx->cpumask)) {
|
|
__blk_mq_run_hw_queue(hctx);
|
|
put_cpu();
|
|
return;
|
|
}
|
|
|
|
put_cpu();
|
|
}
|
|
|
|
kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
|
|
&hctx->run_work, 0);
|
|
}
|
|
|
|
static void blk_mq_run_queues(struct request_queue *q)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if ((!blk_mq_hctx_has_pending(hctx) &&
|
|
list_empty_careful(&hctx->dispatch)) ||
|
|
test_bit(BLK_MQ_S_STOPPED, &hctx->state))
|
|
continue;
|
|
|
|
blk_mq_run_hw_queue(hctx, false);
|
|
}
|
|
}
|
|
|
|
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
cancel_delayed_work(&hctx->run_work);
|
|
cancel_delayed_work(&hctx->delay_work);
|
|
set_bit(BLK_MQ_S_STOPPED, &hctx->state);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_stop_hw_queue);
|
|
|
|
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_queues(struct request_queue *q, bool async)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
|
|
continue;
|
|
|
|
clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
|
|
blk_mq_run_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);
|
|
|
|
__blk_mq_run_hw_queue(hctx);
|
|
}
|
|
|
|
static void blk_mq_delay_work_fn(struct work_struct *work)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
|
|
hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work);
|
|
|
|
if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state))
|
|
__blk_mq_run_hw_queue(hctx);
|
|
}
|
|
|
|
void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
|
|
{
|
|
if (unlikely(!blk_mq_hw_queue_mapped(hctx)))
|
|
return;
|
|
|
|
kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
|
|
&hctx->delay_work, msecs_to_jiffies(msecs));
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_delay_queue);
|
|
|
|
static 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;
|
|
|
|
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);
|
|
|
|
blk_mq_hctx_mark_pending(hctx, ctx);
|
|
}
|
|
|
|
void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
|
|
bool async)
|
|
{
|
|
struct request_queue *q = rq->q;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx;
|
|
|
|
current_ctx = blk_mq_get_ctx(q);
|
|
if (!cpu_online(ctx->cpu))
|
|
rq->mq_ctx = ctx = current_ctx;
|
|
|
|
hctx = q->mq_ops->map_queue(q, ctx->cpu);
|
|
|
|
spin_lock(&ctx->lock);
|
|
__blk_mq_insert_request(hctx, rq, at_head);
|
|
spin_unlock(&ctx->lock);
|
|
|
|
if (run_queue)
|
|
blk_mq_run_hw_queue(hctx, async);
|
|
|
|
blk_mq_put_ctx(current_ctx);
|
|
}
|
|
|
|
static void blk_mq_insert_requests(struct request_queue *q,
|
|
struct blk_mq_ctx *ctx,
|
|
struct list_head *list,
|
|
int depth,
|
|
bool from_schedule)
|
|
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *current_ctx;
|
|
|
|
trace_block_unplug(q, depth, !from_schedule);
|
|
|
|
current_ctx = blk_mq_get_ctx(q);
|
|
|
|
if (!cpu_online(ctx->cpu))
|
|
ctx = current_ctx;
|
|
hctx = q->mq_ops->map_queue(q, ctx->cpu);
|
|
|
|
/*
|
|
* 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);
|
|
list_del_init(&rq->queuelist);
|
|
rq->mq_ctx = ctx;
|
|
__blk_mq_insert_request(hctx, rq, false);
|
|
}
|
|
spin_unlock(&ctx->lock);
|
|
|
|
blk_mq_run_hw_queue(hctx, from_schedule);
|
|
blk_mq_put_ctx(current_ctx);
|
|
}
|
|
|
|
static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
|
|
{
|
|
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) {
|
|
blk_mq_insert_requests(this_q, this_ctx,
|
|
&ctx_list, depth,
|
|
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) {
|
|
blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth,
|
|
from_schedule);
|
|
}
|
|
}
|
|
|
|
static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
|
|
{
|
|
init_request_from_bio(rq, bio);
|
|
|
|
if (blk_do_io_stat(rq))
|
|
blk_account_io_start(rq, 1);
|
|
}
|
|
|
|
static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx)
|
|
{
|
|
return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
|
|
!blk_queue_nomerges(hctx->queue);
|
|
}
|
|
|
|
static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
|
|
struct blk_mq_ctx *ctx,
|
|
struct request *rq, struct bio *bio)
|
|
{
|
|
if (!hctx_allow_merges(hctx)) {
|
|
blk_mq_bio_to_request(rq, bio);
|
|
spin_lock(&ctx->lock);
|
|
insert_rq:
|
|
__blk_mq_insert_request(hctx, rq, false);
|
|
spin_unlock(&ctx->lock);
|
|
return false;
|
|
} else {
|
|
struct request_queue *q = hctx->queue;
|
|
|
|
spin_lock(&ctx->lock);
|
|
if (!blk_mq_attempt_merge(q, ctx, bio)) {
|
|
blk_mq_bio_to_request(rq, bio);
|
|
goto insert_rq;
|
|
}
|
|
|
|
spin_unlock(&ctx->lock);
|
|
__blk_mq_free_request(hctx, ctx, rq);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
struct blk_map_ctx {
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx;
|
|
};
|
|
|
|
static struct request *blk_mq_map_request(struct request_queue *q,
|
|
struct bio *bio,
|
|
struct blk_map_ctx *data)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx;
|
|
struct request *rq;
|
|
int rw = bio_data_dir(bio);
|
|
struct blk_mq_alloc_data alloc_data;
|
|
|
|
if (unlikely(blk_mq_queue_enter(q))) {
|
|
bio_endio(bio, -EIO);
|
|
return NULL;
|
|
}
|
|
|
|
ctx = blk_mq_get_ctx(q);
|
|
hctx = q->mq_ops->map_queue(q, ctx->cpu);
|
|
|
|
if (rw_is_sync(bio->bi_rw))
|
|
rw |= REQ_SYNC;
|
|
|
|
trace_block_getrq(q, bio, rw);
|
|
blk_mq_set_alloc_data(&alloc_data, q, GFP_ATOMIC, false, ctx,
|
|
hctx);
|
|
rq = __blk_mq_alloc_request(&alloc_data, rw);
|
|
if (unlikely(!rq)) {
|
|
__blk_mq_run_hw_queue(hctx);
|
|
blk_mq_put_ctx(ctx);
|
|
trace_block_sleeprq(q, bio, rw);
|
|
|
|
ctx = blk_mq_get_ctx(q);
|
|
hctx = q->mq_ops->map_queue(q, ctx->cpu);
|
|
blk_mq_set_alloc_data(&alloc_data, q,
|
|
__GFP_WAIT|GFP_ATOMIC, false, ctx, hctx);
|
|
rq = __blk_mq_alloc_request(&alloc_data, rw);
|
|
ctx = alloc_data.ctx;
|
|
hctx = alloc_data.hctx;
|
|
}
|
|
|
|
hctx->queued++;
|
|
data->hctx = hctx;
|
|
data->ctx = ctx;
|
|
return rq;
|
|
}
|
|
|
|
/*
|
|
* Multiple hardware queue variant. This will not use per-process plugs,
|
|
* but will attempt to bypass the hctx queueing if we can go straight to
|
|
* hardware for SYNC IO.
|
|
*/
|
|
static void blk_mq_make_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
const int is_sync = rw_is_sync(bio->bi_rw);
|
|
const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
|
|
struct blk_map_ctx data;
|
|
struct request *rq;
|
|
|
|
blk_queue_bounce(q, &bio);
|
|
|
|
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
|
|
bio_endio(bio, -EIO);
|
|
return;
|
|
}
|
|
|
|
rq = blk_mq_map_request(q, bio, &data);
|
|
if (unlikely(!rq))
|
|
return;
|
|
|
|
if (unlikely(is_flush_fua)) {
|
|
blk_mq_bio_to_request(rq, bio);
|
|
blk_insert_flush(rq);
|
|
goto run_queue;
|
|
}
|
|
|
|
/*
|
|
* If the driver supports defer issued based on 'last', then
|
|
* queue it up like normal since we can potentially save some
|
|
* CPU this way.
|
|
*/
|
|
if (is_sync && !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
|
|
struct blk_mq_queue_data bd = {
|
|
.rq = rq,
|
|
.list = NULL,
|
|
.last = 1
|
|
};
|
|
int ret;
|
|
|
|
blk_mq_bio_to_request(rq, bio);
|
|
|
|
/*
|
|
* For OK queue, we are done. For error, kill it. Any other
|
|
* error (busy), just add it to our list as we previously
|
|
* would have done
|
|
*/
|
|
ret = q->mq_ops->queue_rq(data.hctx, &bd);
|
|
if (ret == BLK_MQ_RQ_QUEUE_OK)
|
|
goto done;
|
|
else {
|
|
__blk_mq_requeue_request(rq);
|
|
|
|
if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
|
|
rq->errors = -EIO;
|
|
blk_mq_end_request(rq, rq->errors);
|
|
goto done;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
|
|
/*
|
|
* For a SYNC request, send it to the hardware immediately. For
|
|
* an ASYNC request, just ensure that we run it later on. The
|
|
* latter allows for merging opportunities and more efficient
|
|
* dispatching.
|
|
*/
|
|
run_queue:
|
|
blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
|
|
}
|
|
done:
|
|
blk_mq_put_ctx(data.ctx);
|
|
}
|
|
|
|
/*
|
|
* Single hardware queue variant. This will attempt to use any per-process
|
|
* plug for merging and IO deferral.
|
|
*/
|
|
static void blk_sq_make_request(struct request_queue *q, struct bio *bio)
|
|
{
|
|
const int is_sync = rw_is_sync(bio->bi_rw);
|
|
const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
|
|
unsigned int use_plug, request_count = 0;
|
|
struct blk_map_ctx data;
|
|
struct request *rq;
|
|
|
|
/*
|
|
* If we have multiple hardware queues, just go directly to
|
|
* one of those for sync IO.
|
|
*/
|
|
use_plug = !is_flush_fua && !is_sync;
|
|
|
|
blk_queue_bounce(q, &bio);
|
|
|
|
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
|
|
bio_endio(bio, -EIO);
|
|
return;
|
|
}
|
|
|
|
if (use_plug && !blk_queue_nomerges(q) &&
|
|
blk_attempt_plug_merge(q, bio, &request_count))
|
|
return;
|
|
|
|
rq = blk_mq_map_request(q, bio, &data);
|
|
if (unlikely(!rq))
|
|
return;
|
|
|
|
if (unlikely(is_flush_fua)) {
|
|
blk_mq_bio_to_request(rq, bio);
|
|
blk_insert_flush(rq);
|
|
goto run_queue;
|
|
}
|
|
|
|
/*
|
|
* A task plug currently exists. Since this is completely lockless,
|
|
* utilize that to temporarily store requests until the task is
|
|
* either done or scheduled away.
|
|
*/
|
|
if (use_plug) {
|
|
struct blk_plug *plug = current->plug;
|
|
|
|
if (plug) {
|
|
blk_mq_bio_to_request(rq, bio);
|
|
if (list_empty(&plug->mq_list))
|
|
trace_block_plug(q);
|
|
else if (request_count >= BLK_MAX_REQUEST_COUNT) {
|
|
blk_flush_plug_list(plug, false);
|
|
trace_block_plug(q);
|
|
}
|
|
list_add_tail(&rq->queuelist, &plug->mq_list);
|
|
blk_mq_put_ctx(data.ctx);
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
|
|
/*
|
|
* For a SYNC request, send it to the hardware immediately. For
|
|
* an ASYNC request, just ensure that we run it later on. The
|
|
* latter allows for merging opportunities and more efficient
|
|
* dispatching.
|
|
*/
|
|
run_queue:
|
|
blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
|
|
}
|
|
|
|
blk_mq_put_ctx(data.ctx);
|
|
}
|
|
|
|
/*
|
|
* Default mapping to a software queue, since we use one per CPU.
|
|
*/
|
|
struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
|
|
{
|
|
return q->queue_hw_ctx[q->mq_map[cpu]];
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_map_queue);
|
|
|
|
static void blk_mq_free_rq_map(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++) {
|
|
if (!tags->rqs[i])
|
|
continue;
|
|
set->ops->exit_request(set->driver_data, tags->rqs[i],
|
|
hctx_idx, i);
|
|
tags->rqs[i] = NULL;
|
|
}
|
|
}
|
|
|
|
while (!list_empty(&tags->page_list)) {
|
|
page = list_first_entry(&tags->page_list, struct page, lru);
|
|
list_del_init(&page->lru);
|
|
__free_pages(page, page->private);
|
|
}
|
|
|
|
kfree(tags->rqs);
|
|
|
|
blk_mq_free_tags(tags);
|
|
}
|
|
|
|
static size_t order_to_size(unsigned int order)
|
|
{
|
|
return (size_t)PAGE_SIZE << order;
|
|
}
|
|
|
|
static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
|
|
unsigned int hctx_idx)
|
|
{
|
|
struct blk_mq_tags *tags;
|
|
unsigned int i, j, entries_per_page, max_order = 4;
|
|
size_t rq_size, left;
|
|
|
|
tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags,
|
|
set->numa_node,
|
|
BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
|
|
if (!tags)
|
|
return NULL;
|
|
|
|
INIT_LIST_HEAD(&tags->page_list);
|
|
|
|
tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *),
|
|
GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
|
|
set->numa_node);
|
|
if (!tags->rqs) {
|
|
blk_mq_free_tags(tags);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* 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 * set->queue_depth;
|
|
|
|
for (i = 0; i < set->queue_depth; ) {
|
|
int this_order = max_order;
|
|
struct page *page;
|
|
int to_do;
|
|
void *p;
|
|
|
|
while (left < order_to_size(this_order - 1) && this_order)
|
|
this_order--;
|
|
|
|
do {
|
|
page = alloc_pages_node(set->numa_node,
|
|
GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
|
|
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);
|
|
entries_per_page = order_to_size(this_order) / rq_size;
|
|
to_do = min(entries_per_page, set->queue_depth - i);
|
|
left -= to_do * rq_size;
|
|
for (j = 0; j < to_do; j++) {
|
|
tags->rqs[i] = p;
|
|
tags->rqs[i]->atomic_flags = 0;
|
|
tags->rqs[i]->cmd_flags = 0;
|
|
if (set->ops->init_request) {
|
|
if (set->ops->init_request(set->driver_data,
|
|
tags->rqs[i], hctx_idx, i,
|
|
set->numa_node)) {
|
|
tags->rqs[i] = NULL;
|
|
goto fail;
|
|
}
|
|
}
|
|
|
|
p += rq_size;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
return tags;
|
|
|
|
fail:
|
|
blk_mq_free_rq_map(set, tags, hctx_idx);
|
|
return NULL;
|
|
}
|
|
|
|
static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap)
|
|
{
|
|
kfree(bitmap->map);
|
|
}
|
|
|
|
static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node)
|
|
{
|
|
unsigned int bpw = 8, total, num_maps, i;
|
|
|
|
bitmap->bits_per_word = bpw;
|
|
|
|
num_maps = ALIGN(nr_cpu_ids, bpw) / bpw;
|
|
bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap),
|
|
GFP_KERNEL, node);
|
|
if (!bitmap->map)
|
|
return -ENOMEM;
|
|
|
|
bitmap->map_size = num_maps;
|
|
|
|
total = nr_cpu_ids;
|
|
for (i = 0; i < num_maps; i++) {
|
|
bitmap->map[i].depth = min(total, bitmap->bits_per_word);
|
|
total -= bitmap->map[i].depth;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu)
|
|
{
|
|
struct request_queue *q = hctx->queue;
|
|
struct blk_mq_ctx *ctx;
|
|
LIST_HEAD(tmp);
|
|
|
|
/*
|
|
* Move ctx entries to new CPU, if this one is going away.
|
|
*/
|
|
ctx = __blk_mq_get_ctx(q, cpu);
|
|
|
|
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 NOTIFY_OK;
|
|
|
|
ctx = blk_mq_get_ctx(q);
|
|
spin_lock(&ctx->lock);
|
|
|
|
while (!list_empty(&tmp)) {
|
|
struct request *rq;
|
|
|
|
rq = list_first_entry(&tmp, struct request, queuelist);
|
|
rq->mq_ctx = ctx;
|
|
list_move_tail(&rq->queuelist, &ctx->rq_list);
|
|
}
|
|
|
|
hctx = q->mq_ops->map_queue(q, ctx->cpu);
|
|
blk_mq_hctx_mark_pending(hctx, ctx);
|
|
|
|
spin_unlock(&ctx->lock);
|
|
|
|
blk_mq_run_hw_queue(hctx, true);
|
|
blk_mq_put_ctx(ctx);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static int blk_mq_hctx_cpu_online(struct blk_mq_hw_ctx *hctx, int cpu)
|
|
{
|
|
struct request_queue *q = hctx->queue;
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
if (set->tags[hctx->queue_num])
|
|
return NOTIFY_OK;
|
|
|
|
set->tags[hctx->queue_num] = blk_mq_init_rq_map(set, hctx->queue_num);
|
|
if (!set->tags[hctx->queue_num])
|
|
return NOTIFY_STOP;
|
|
|
|
hctx->tags = set->tags[hctx->queue_num];
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static int blk_mq_hctx_notify(void *data, unsigned long action,
|
|
unsigned int cpu)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx = data;
|
|
|
|
if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
|
|
return blk_mq_hctx_cpu_offline(hctx, cpu);
|
|
else if (action == CPU_ONLINE || action == CPU_ONLINE_FROZEN)
|
|
return blk_mq_hctx_cpu_online(hctx, cpu);
|
|
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
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)
|
|
{
|
|
unsigned flush_start_tag = set->queue_depth;
|
|
|
|
blk_mq_tag_idle(hctx);
|
|
|
|
if (set->ops->exit_request)
|
|
set->ops->exit_request(set->driver_data,
|
|
hctx->fq->flush_rq, hctx_idx,
|
|
flush_start_tag + hctx_idx);
|
|
|
|
if (set->ops->exit_hctx)
|
|
set->ops->exit_hctx(hctx, hctx_idx);
|
|
|
|
blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
|
|
blk_free_flush_queue(hctx->fq);
|
|
kfree(hctx->ctxs);
|
|
blk_mq_free_bitmap(&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 void blk_mq_free_hw_queues(struct request_queue *q,
|
|
struct blk_mq_tag_set *set)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
unsigned int i;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i)
|
|
free_cpumask_var(hctx->cpumask);
|
|
}
|
|
|
|
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;
|
|
unsigned flush_start_tag = set->queue_depth;
|
|
|
|
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);
|
|
INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
|
|
spin_lock_init(&hctx->lock);
|
|
INIT_LIST_HEAD(&hctx->dispatch);
|
|
hctx->queue = q;
|
|
hctx->queue_num = hctx_idx;
|
|
hctx->flags = set->flags;
|
|
|
|
blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
|
|
blk_mq_hctx_notify, hctx);
|
|
blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
|
|
|
|
hctx->tags = set->tags[hctx_idx];
|
|
|
|
/*
|
|
* Allocate space for all possible cpus to avoid allocation at
|
|
* runtime
|
|
*/
|
|
hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
|
|
GFP_KERNEL, node);
|
|
if (!hctx->ctxs)
|
|
goto unregister_cpu_notifier;
|
|
|
|
if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
|
|
goto free_ctxs;
|
|
|
|
hctx->nr_ctx = 0;
|
|
|
|
if (set->ops->init_hctx &&
|
|
set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
|
|
goto free_bitmap;
|
|
|
|
hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
|
|
if (!hctx->fq)
|
|
goto exit_hctx;
|
|
|
|
if (set->ops->init_request &&
|
|
set->ops->init_request(set->driver_data,
|
|
hctx->fq->flush_rq, hctx_idx,
|
|
flush_start_tag + hctx_idx, node))
|
|
goto free_fq;
|
|
|
|
return 0;
|
|
|
|
free_fq:
|
|
kfree(hctx->fq);
|
|
exit_hctx:
|
|
if (set->ops->exit_hctx)
|
|
set->ops->exit_hctx(hctx, hctx_idx);
|
|
free_bitmap:
|
|
blk_mq_free_bitmap(&hctx->ctx_map);
|
|
free_ctxs:
|
|
kfree(hctx->ctxs);
|
|
unregister_cpu_notifier:
|
|
blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int blk_mq_init_hw_queues(struct request_queue *q,
|
|
struct blk_mq_tag_set *set)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
unsigned int i;
|
|
|
|
/*
|
|
* Initialize hardware queues
|
|
*/
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (blk_mq_init_hctx(q, set, hctx, i))
|
|
break;
|
|
}
|
|
|
|
if (i == q->nr_hw_queues)
|
|
return 0;
|
|
|
|
/*
|
|
* Init failed
|
|
*/
|
|
blk_mq_exit_hw_queues(q, set, i);
|
|
|
|
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;
|
|
|
|
memset(__ctx, 0, sizeof(*__ctx));
|
|
__ctx->cpu = i;
|
|
spin_lock_init(&__ctx->lock);
|
|
INIT_LIST_HEAD(&__ctx->rq_list);
|
|
__ctx->queue = q;
|
|
|
|
/* If the cpu isn't online, the cpu is mapped to first hctx */
|
|
if (!cpu_online(i))
|
|
continue;
|
|
|
|
hctx = q->mq_ops->map_queue(q, i);
|
|
cpumask_set_cpu(i, hctx->cpumask);
|
|
hctx->nr_ctx++;
|
|
|
|
/*
|
|
* Set local node, IFF we have more than one hw queue. If
|
|
* not, we remain on the home node of the device
|
|
*/
|
|
if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
|
|
hctx->numa_node = cpu_to_node(i);
|
|
}
|
|
}
|
|
|
|
static void blk_mq_map_swqueue(struct request_queue *q)
|
|
{
|
|
unsigned int i;
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct blk_mq_ctx *ctx;
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
cpumask_clear(hctx->cpumask);
|
|
hctx->nr_ctx = 0;
|
|
}
|
|
|
|
/*
|
|
* Map software to hardware queues
|
|
*/
|
|
queue_for_each_ctx(q, ctx, i) {
|
|
/* If the cpu isn't online, the cpu is mapped to first hctx */
|
|
if (!cpu_online(i))
|
|
continue;
|
|
|
|
hctx = q->mq_ops->map_queue(q, i);
|
|
cpumask_set_cpu(i, hctx->cpumask);
|
|
ctx->index_hw = hctx->nr_ctx;
|
|
hctx->ctxs[hctx->nr_ctx++] = ctx;
|
|
}
|
|
|
|
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) {
|
|
struct blk_mq_tag_set *set = q->tag_set;
|
|
|
|
if (set->tags[i]) {
|
|
blk_mq_free_rq_map(set, set->tags[i], i);
|
|
set->tags[i] = NULL;
|
|
hctx->tags = NULL;
|
|
}
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Initialize batch roundrobin counts
|
|
*/
|
|
hctx->next_cpu = cpumask_first(hctx->cpumask);
|
|
hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
|
|
}
|
|
}
|
|
|
|
static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set)
|
|
{
|
|
struct blk_mq_hw_ctx *hctx;
|
|
struct request_queue *q;
|
|
bool shared;
|
|
int i;
|
|
|
|
if (set->tag_list.next == set->tag_list.prev)
|
|
shared = false;
|
|
else
|
|
shared = true;
|
|
|
|
list_for_each_entry(q, &set->tag_list, tag_set_list) {
|
|
blk_mq_freeze_queue(q);
|
|
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
if (shared)
|
|
hctx->flags |= BLK_MQ_F_TAG_SHARED;
|
|
else
|
|
hctx->flags &= ~BLK_MQ_F_TAG_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_init(&q->tag_set_list);
|
|
blk_mq_update_tag_set_depth(set);
|
|
mutex_unlock(&set->tag_list_lock);
|
|
}
|
|
|
|
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);
|
|
list_add_tail(&q->tag_set_list, &set->tag_list);
|
|
blk_mq_update_tag_set_depth(set);
|
|
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)
|
|
kfree(hctx);
|
|
|
|
kfree(q->queue_hw_ctx);
|
|
|
|
/* ctx kobj stays in queue_ctx */
|
|
free_percpu(q->queue_ctx);
|
|
}
|
|
|
|
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
|
|
{
|
|
struct blk_mq_hw_ctx **hctxs;
|
|
struct blk_mq_ctx __percpu *ctx;
|
|
struct request_queue *q;
|
|
unsigned int *map;
|
|
int i;
|
|
|
|
ctx = alloc_percpu(struct blk_mq_ctx);
|
|
if (!ctx)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
hctxs = kmalloc_node(set->nr_hw_queues * sizeof(*hctxs), GFP_KERNEL,
|
|
set->numa_node);
|
|
|
|
if (!hctxs)
|
|
goto err_percpu;
|
|
|
|
map = blk_mq_make_queue_map(set);
|
|
if (!map)
|
|
goto err_map;
|
|
|
|
for (i = 0; i < set->nr_hw_queues; i++) {
|
|
int node = blk_mq_hw_queue_to_node(map, i);
|
|
|
|
hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
|
|
GFP_KERNEL, node);
|
|
if (!hctxs[i])
|
|
goto err_hctxs;
|
|
|
|
if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
|
|
node))
|
|
goto err_hctxs;
|
|
|
|
atomic_set(&hctxs[i]->nr_active, 0);
|
|
hctxs[i]->numa_node = node;
|
|
hctxs[i]->queue_num = i;
|
|
}
|
|
|
|
q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
|
|
if (!q)
|
|
goto err_hctxs;
|
|
|
|
/*
|
|
* Init percpu_ref in atomic mode so that it's faster to shutdown.
|
|
* See blk_register_queue() for details.
|
|
*/
|
|
if (percpu_ref_init(&q->mq_usage_counter, blk_mq_usage_counter_release,
|
|
PERCPU_REF_INIT_ATOMIC, GFP_KERNEL))
|
|
goto err_map;
|
|
|
|
setup_timer(&q->timeout, blk_mq_rq_timer, (unsigned long) q);
|
|
blk_queue_rq_timeout(q, 30000);
|
|
|
|
q->nr_queues = nr_cpu_ids;
|
|
q->nr_hw_queues = set->nr_hw_queues;
|
|
q->mq_map = map;
|
|
|
|
q->queue_ctx = ctx;
|
|
q->queue_hw_ctx = hctxs;
|
|
|
|
q->mq_ops = set->ops;
|
|
q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
|
|
|
|
if (!(set->flags & BLK_MQ_F_SG_MERGE))
|
|
q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE;
|
|
|
|
q->sg_reserved_size = INT_MAX;
|
|
|
|
INIT_WORK(&q->requeue_work, blk_mq_requeue_work);
|
|
INIT_LIST_HEAD(&q->requeue_list);
|
|
spin_lock_init(&q->requeue_lock);
|
|
|
|
if (q->nr_hw_queues > 1)
|
|
blk_queue_make_request(q, blk_mq_make_request);
|
|
else
|
|
blk_queue_make_request(q, blk_sq_make_request);
|
|
|
|
if (set->timeout)
|
|
blk_queue_rq_timeout(q, set->timeout);
|
|
|
|
/*
|
|
* Do this after blk_queue_make_request() overrides it...
|
|
*/
|
|
q->nr_requests = set->queue_depth;
|
|
|
|
if (set->ops->complete)
|
|
blk_queue_softirq_done(q, set->ops->complete);
|
|
|
|
blk_mq_init_cpu_queues(q, set->nr_hw_queues);
|
|
|
|
if (blk_mq_init_hw_queues(q, set))
|
|
goto err_hw;
|
|
|
|
mutex_lock(&all_q_mutex);
|
|
list_add_tail(&q->all_q_node, &all_q_list);
|
|
mutex_unlock(&all_q_mutex);
|
|
|
|
blk_mq_add_queue_tag_set(set, q);
|
|
|
|
blk_mq_map_swqueue(q);
|
|
|
|
return q;
|
|
|
|
err_hw:
|
|
blk_cleanup_queue(q);
|
|
err_hctxs:
|
|
kfree(map);
|
|
for (i = 0; i < set->nr_hw_queues; i++) {
|
|
if (!hctxs[i])
|
|
break;
|
|
free_cpumask_var(hctxs[i]->cpumask);
|
|
kfree(hctxs[i]);
|
|
}
|
|
err_map:
|
|
kfree(hctxs);
|
|
err_percpu:
|
|
free_percpu(ctx);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
EXPORT_SYMBOL(blk_mq_init_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);
|
|
blk_mq_free_hw_queues(q, set);
|
|
|
|
percpu_ref_exit(&q->mq_usage_counter);
|
|
|
|
kfree(q->mq_map);
|
|
|
|
q->mq_map = NULL;
|
|
|
|
mutex_lock(&all_q_mutex);
|
|
list_del_init(&q->all_q_node);
|
|
mutex_unlock(&all_q_mutex);
|
|
}
|
|
|
|
/* Basically redo blk_mq_init_queue with queue frozen */
|
|
static void blk_mq_queue_reinit(struct request_queue *q)
|
|
{
|
|
WARN_ON_ONCE(!q->mq_freeze_depth);
|
|
|
|
blk_mq_sysfs_unregister(q);
|
|
|
|
blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues);
|
|
|
|
/*
|
|
* redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
|
|
* we should change hctx numa_node according to new topology (this
|
|
* involves free and re-allocate memory, worthy doing?)
|
|
*/
|
|
|
|
blk_mq_map_swqueue(q);
|
|
|
|
blk_mq_sysfs_register(q);
|
|
}
|
|
|
|
static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
|
|
unsigned long action, void *hcpu)
|
|
{
|
|
struct request_queue *q;
|
|
|
|
/*
|
|
* Before new mappings are established, hotadded cpu might already
|
|
* start handling requests. This doesn't break anything as we map
|
|
* offline CPUs to first hardware queue. We will re-init the queue
|
|
* below to get optimal settings.
|
|
*/
|
|
if (action != CPU_DEAD && action != CPU_DEAD_FROZEN &&
|
|
action != CPU_ONLINE && action != CPU_ONLINE_FROZEN)
|
|
return NOTIFY_OK;
|
|
|
|
mutex_lock(&all_q_mutex);
|
|
|
|
/*
|
|
* We need to freeze and reinit all existing queues. Freezing
|
|
* involves synchronous wait for an RCU grace period and doing it
|
|
* one by one may take a long time. Start freezing all queues in
|
|
* one swoop and then wait for the completions so that freezing can
|
|
* take place in parallel.
|
|
*/
|
|
list_for_each_entry(q, &all_q_list, all_q_node)
|
|
blk_mq_freeze_queue_start(q);
|
|
list_for_each_entry(q, &all_q_list, all_q_node)
|
|
blk_mq_freeze_queue_wait(q);
|
|
|
|
list_for_each_entry(q, &all_q_list, all_q_node)
|
|
blk_mq_queue_reinit(q);
|
|
|
|
list_for_each_entry(q, &all_q_list, all_q_node)
|
|
blk_mq_unfreeze_queue(q);
|
|
|
|
mutex_unlock(&all_q_mutex);
|
|
return NOTIFY_OK;
|
|
}
|
|
|
|
static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < set->nr_hw_queues; i++) {
|
|
set->tags[i] = blk_mq_init_rq_map(set, i);
|
|
if (!set->tags[i])
|
|
goto out_unwind;
|
|
}
|
|
|
|
return 0;
|
|
|
|
out_unwind:
|
|
while (--i >= 0)
|
|
blk_mq_free_rq_map(set, set->tags[i], 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;
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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->nr_hw_queues || !set->ops->queue_rq || !set->ops->map_queue)
|
|
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);
|
|
}
|
|
|
|
set->tags = kmalloc_node(set->nr_hw_queues *
|
|
sizeof(struct blk_mq_tags *),
|
|
GFP_KERNEL, set->numa_node);
|
|
if (!set->tags)
|
|
return -ENOMEM;
|
|
|
|
if (blk_mq_alloc_rq_maps(set))
|
|
goto enomem;
|
|
|
|
mutex_init(&set->tag_list_lock);
|
|
INIT_LIST_HEAD(&set->tag_list);
|
|
|
|
return 0;
|
|
enomem:
|
|
kfree(set->tags);
|
|
set->tags = NULL;
|
|
return -ENOMEM;
|
|
}
|
|
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 < set->nr_hw_queues; i++) {
|
|
if (set->tags[i])
|
|
blk_mq_free_rq_map(set, set->tags[i], i);
|
|
}
|
|
|
|
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 || nr > set->queue_depth)
|
|
return -EINVAL;
|
|
|
|
ret = 0;
|
|
queue_for_each_hw_ctx(q, hctx, i) {
|
|
ret = blk_mq_tag_update_depth(hctx->tags, nr);
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
if (!ret)
|
|
q->nr_requests = nr;
|
|
|
|
return ret;
|
|
}
|
|
|
|
void blk_mq_disable_hotplug(void)
|
|
{
|
|
mutex_lock(&all_q_mutex);
|
|
}
|
|
|
|
void blk_mq_enable_hotplug(void)
|
|
{
|
|
mutex_unlock(&all_q_mutex);
|
|
}
|
|
|
|
static int __init blk_mq_init(void)
|
|
{
|
|
blk_mq_cpu_init();
|
|
|
|
hotcpu_notifier(blk_mq_queue_reinit_notify, 0);
|
|
|
|
return 0;
|
|
}
|
|
subsys_initcall(blk_mq_init);
|