blob: f9b9049b1284cc8adf65c1eed611e4c09d2d6584 [file] [log] [blame]
Jens Axboe75bb4622014-05-28 10:15:41 -06001/*
2 * Block multiqueue core code
3 *
4 * Copyright (C) 2013-2014 Jens Axboe
5 * Copyright (C) 2013-2014 Christoph Hellwig
6 */
Jens Axboe320ae512013-10-24 09:20:05 +01007#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/backing-dev.h>
10#include <linux/bio.h>
11#include <linux/blkdev.h>
Catalin Marinasf75782e2015-09-14 18:16:02 +010012#include <linux/kmemleak.h>
Jens Axboe320ae512013-10-24 09:20:05 +010013#include <linux/mm.h>
14#include <linux/init.h>
15#include <linux/slab.h>
16#include <linux/workqueue.h>
17#include <linux/smp.h>
18#include <linux/llist.h>
19#include <linux/list_sort.h>
20#include <linux/cpu.h>
21#include <linux/cache.h>
22#include <linux/sched/sysctl.h>
23#include <linux/delay.h>
Jens Axboeaedcd722014-09-17 08:27:03 -060024#include <linux/crash_dump.h>
Jens Axboe320ae512013-10-24 09:20:05 +010025
26#include <trace/events/block.h>
27
28#include <linux/blk-mq.h>
29#include "blk.h"
30#include "blk-mq.h"
31#include "blk-mq-tag.h"
32
33static DEFINE_MUTEX(all_q_mutex);
34static LIST_HEAD(all_q_list);
35
36static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx);
37
Jens Axboe320ae512013-10-24 09:20:05 +010038/*
39 * Check if any of the ctx's have pending work in this hardware queue
40 */
41static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx *hctx)
42{
43 unsigned int i;
44
Jens Axboe569fd0c2015-04-17 08:28:50 -060045 for (i = 0; i < hctx->ctx_map.size; i++)
Jens Axboe1429d7c2014-05-19 09:23:55 -060046 if (hctx->ctx_map.map[i].word)
Jens Axboe320ae512013-10-24 09:20:05 +010047 return true;
48
49 return false;
50}
51
Jens Axboe1429d7c2014-05-19 09:23:55 -060052static inline struct blk_align_bitmap *get_bm(struct blk_mq_hw_ctx *hctx,
53 struct blk_mq_ctx *ctx)
54{
55 return &hctx->ctx_map.map[ctx->index_hw / hctx->ctx_map.bits_per_word];
56}
57
58#define CTX_TO_BIT(hctx, ctx) \
59 ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1))
60
Jens Axboe320ae512013-10-24 09:20:05 +010061/*
62 * Mark this ctx as having pending work in this hardware queue
63 */
64static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx *hctx,
65 struct blk_mq_ctx *ctx)
66{
Jens Axboe1429d7c2014-05-19 09:23:55 -060067 struct blk_align_bitmap *bm = get_bm(hctx, ctx);
68
69 if (!test_bit(CTX_TO_BIT(hctx, ctx), &bm->word))
70 set_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
71}
72
73static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx *hctx,
74 struct blk_mq_ctx *ctx)
75{
76 struct blk_align_bitmap *bm = get_bm(hctx, ctx);
77
78 clear_bit(CTX_TO_BIT(hctx, ctx), &bm->word);
Jens Axboe320ae512013-10-24 09:20:05 +010079}
80
Keith Buschb4c6a022014-12-19 17:54:14 -070081void blk_mq_freeze_queue_start(struct request_queue *q)
Ming Lei43a5e4e2013-12-26 21:31:35 +080082{
Christoph Hellwig4ecd4fe2015-05-07 09:38:13 +020083 int freeze_depth;
Tejun Heocddd5d12014-08-16 08:02:24 -040084
Christoph Hellwig4ecd4fe2015-05-07 09:38:13 +020085 freeze_depth = atomic_inc_return(&q->mq_freeze_depth);
86 if (freeze_depth == 1) {
Dan Williams3ef28e82015-10-21 13:20:12 -040087 percpu_ref_kill(&q->q_usage_counter);
Mike Snitzerb94ec292015-03-11 23:56:38 -040088 blk_mq_run_hw_queues(q, false);
Tejun Heocddd5d12014-08-16 08:02:24 -040089 }
Tejun Heof3af0202014-11-04 13:52:27 -050090}
Keith Buschb4c6a022014-12-19 17:54:14 -070091EXPORT_SYMBOL_GPL(blk_mq_freeze_queue_start);
Tejun Heof3af0202014-11-04 13:52:27 -050092
93static void blk_mq_freeze_queue_wait(struct request_queue *q)
94{
Dan Williams3ef28e82015-10-21 13:20:12 -040095 wait_event(q->mq_freeze_wq, percpu_ref_is_zero(&q->q_usage_counter));
Ming Lei43a5e4e2013-12-26 21:31:35 +080096}
97
Tejun Heof3af0202014-11-04 13:52:27 -050098/*
99 * Guarantee no request is in use, so we can change any data structure of
100 * the queue afterward.
101 */
Dan Williams3ef28e82015-10-21 13:20:12 -0400102void blk_freeze_queue(struct request_queue *q)
Tejun Heof3af0202014-11-04 13:52:27 -0500103{
Dan Williams3ef28e82015-10-21 13:20:12 -0400104 /*
105 * In the !blk_mq case we are only calling this to kill the
106 * q_usage_counter, otherwise this increases the freeze depth
107 * and waits for it to return to zero. For this reason there is
108 * no blk_unfreeze_queue(), and blk_freeze_queue() is not
109 * exported to drivers as the only user for unfreeze is blk_mq.
110 */
Tejun Heof3af0202014-11-04 13:52:27 -0500111 blk_mq_freeze_queue_start(q);
112 blk_mq_freeze_queue_wait(q);
113}
Dan Williams3ef28e82015-10-21 13:20:12 -0400114
115void blk_mq_freeze_queue(struct request_queue *q)
116{
117 /*
118 * ...just an alias to keep freeze and unfreeze actions balanced
119 * in the blk_mq_* namespace
120 */
121 blk_freeze_queue(q);
122}
Jens Axboec761d962015-01-02 15:05:12 -0700123EXPORT_SYMBOL_GPL(blk_mq_freeze_queue);
Tejun Heof3af0202014-11-04 13:52:27 -0500124
Keith Buschb4c6a022014-12-19 17:54:14 -0700125void blk_mq_unfreeze_queue(struct request_queue *q)
Jens Axboe320ae512013-10-24 09:20:05 +0100126{
Christoph Hellwig4ecd4fe2015-05-07 09:38:13 +0200127 int freeze_depth;
Jens Axboe320ae512013-10-24 09:20:05 +0100128
Christoph Hellwig4ecd4fe2015-05-07 09:38:13 +0200129 freeze_depth = atomic_dec_return(&q->mq_freeze_depth);
130 WARN_ON_ONCE(freeze_depth < 0);
131 if (!freeze_depth) {
Dan Williams3ef28e82015-10-21 13:20:12 -0400132 percpu_ref_reinit(&q->q_usage_counter);
Jens Axboe320ae512013-10-24 09:20:05 +0100133 wake_up_all(&q->mq_freeze_wq);
Tejun Heoadd703f2014-07-01 10:34:38 -0600134 }
Jens Axboe320ae512013-10-24 09:20:05 +0100135}
Keith Buschb4c6a022014-12-19 17:54:14 -0700136EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue);
Jens Axboe320ae512013-10-24 09:20:05 +0100137
Jens Axboeaed3ea92014-12-22 14:04:42 -0700138void blk_mq_wake_waiters(struct request_queue *q)
139{
140 struct blk_mq_hw_ctx *hctx;
141 unsigned int i;
142
143 queue_for_each_hw_ctx(q, hctx, i)
144 if (blk_mq_hw_queue_mapped(hctx))
145 blk_mq_tag_wakeup_all(hctx->tags, true);
Keith Busch3fd59402015-01-08 08:53:56 -0700146
147 /*
148 * If we are called because the queue has now been marked as
149 * dying, we need to ensure that processes currently waiting on
150 * the queue are notified as well.
151 */
152 wake_up_all(&q->mq_freeze_wq);
Jens Axboeaed3ea92014-12-22 14:04:42 -0700153}
154
Jens Axboe320ae512013-10-24 09:20:05 +0100155bool blk_mq_can_queue(struct blk_mq_hw_ctx *hctx)
156{
157 return blk_mq_has_free_tags(hctx->tags);
158}
159EXPORT_SYMBOL(blk_mq_can_queue);
160
Jens Axboe94eddfb2013-11-19 09:25:07 -0700161static void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
162 struct request *rq, unsigned int rw_flags)
Jens Axboe320ae512013-10-24 09:20:05 +0100163{
Jens Axboe94eddfb2013-11-19 09:25:07 -0700164 if (blk_queue_io_stat(q))
165 rw_flags |= REQ_IO_STAT;
166
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200167 INIT_LIST_HEAD(&rq->queuelist);
168 /* csd/requeue_work/fifo_time is initialized before use */
169 rq->q = q;
Jens Axboe320ae512013-10-24 09:20:05 +0100170 rq->mq_ctx = ctx;
Jens Axboe0d2602c2014-05-13 15:10:52 -0600171 rq->cmd_flags |= rw_flags;
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200172 /* do not touch atomic flags, it needs atomic ops against the timer */
173 rq->cpu = -1;
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200174 INIT_HLIST_NODE(&rq->hash);
175 RB_CLEAR_NODE(&rq->rb_node);
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200176 rq->rq_disk = NULL;
177 rq->part = NULL;
Jens Axboe3ee32372014-06-09 09:36:53 -0600178 rq->start_time = jiffies;
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200179#ifdef CONFIG_BLK_CGROUP
180 rq->rl = NULL;
Ming Lei0fec08b2014-01-03 10:00:08 -0700181 set_start_time_ns(rq);
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200182 rq->io_start_time_ns = 0;
183#endif
184 rq->nr_phys_segments = 0;
185#if defined(CONFIG_BLK_DEV_INTEGRITY)
186 rq->nr_integrity_segments = 0;
187#endif
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200188 rq->special = NULL;
189 /* tag was already set */
190 rq->errors = 0;
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200191
Tony Battersby6f4a16262014-08-22 15:53:39 -0400192 rq->cmd = rq->__cmd;
193
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200194 rq->extra_len = 0;
195 rq->sense_len = 0;
196 rq->resid_len = 0;
197 rq->sense = NULL;
198
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200199 INIT_LIST_HEAD(&rq->timeout_list);
Jens Axboef6be4fb2014-06-06 11:03:48 -0600200 rq->timeout = 0;
201
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200202 rq->end_io = NULL;
203 rq->end_io_data = NULL;
204 rq->next_rq = NULL;
205
Jens Axboe320ae512013-10-24 09:20:05 +0100206 ctx->rq_dispatched[rw_is_sync(rw_flags)]++;
207}
208
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200209static struct request *
Ming Leicb96a422014-06-01 00:43:37 +0800210__blk_mq_alloc_request(struct blk_mq_alloc_data *data, int rw)
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200211{
212 struct request *rq;
213 unsigned int tag;
214
Ming Leicb96a422014-06-01 00:43:37 +0800215 tag = blk_mq_get_tag(data);
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200216 if (tag != BLK_MQ_TAG_FAIL) {
Ming Leicb96a422014-06-01 00:43:37 +0800217 rq = data->hctx->tags->rqs[tag];
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200218
Ming Leicb96a422014-06-01 00:43:37 +0800219 if (blk_mq_tag_busy(data->hctx)) {
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200220 rq->cmd_flags = REQ_MQ_INFLIGHT;
Ming Leicb96a422014-06-01 00:43:37 +0800221 atomic_inc(&data->hctx->nr_active);
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200222 }
223
224 rq->tag = tag;
Ming Leicb96a422014-06-01 00:43:37 +0800225 blk_mq_rq_ctx_init(data->q, data->ctx, rq, rw);
Christoph Hellwig5dee8572014-05-27 20:59:47 +0200226 return rq;
227 }
228
229 return NULL;
230}
231
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +0100232struct request *blk_mq_alloc_request(struct request_queue *q, int rw,
233 unsigned int flags)
Jens Axboe320ae512013-10-24 09:20:05 +0100234{
Christoph Hellwigd8525642014-05-27 20:59:50 +0200235 struct blk_mq_ctx *ctx;
236 struct blk_mq_hw_ctx *hctx;
Jens Axboe320ae512013-10-24 09:20:05 +0100237 struct request *rq;
Ming Leicb96a422014-06-01 00:43:37 +0800238 struct blk_mq_alloc_data alloc_data;
Joe Lawrencea492f072014-08-28 08:15:21 -0600239 int ret;
Jens Axboe320ae512013-10-24 09:20:05 +0100240
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +0100241 ret = blk_queue_enter(q, flags & BLK_MQ_REQ_NOWAIT);
Joe Lawrencea492f072014-08-28 08:15:21 -0600242 if (ret)
243 return ERR_PTR(ret);
Jens Axboe320ae512013-10-24 09:20:05 +0100244
Christoph Hellwigd8525642014-05-27 20:59:50 +0200245 ctx = blk_mq_get_ctx(q);
246 hctx = q->mq_ops->map_queue(q, ctx->cpu);
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +0100247 blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
Christoph Hellwigd8525642014-05-27 20:59:50 +0200248
Ming Leicb96a422014-06-01 00:43:37 +0800249 rq = __blk_mq_alloc_request(&alloc_data, rw);
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +0100250 if (!rq && !(flags & BLK_MQ_REQ_NOWAIT)) {
Christoph Hellwigd8525642014-05-27 20:59:50 +0200251 __blk_mq_run_hw_queue(hctx);
252 blk_mq_put_ctx(ctx);
253
254 ctx = blk_mq_get_ctx(q);
255 hctx = q->mq_ops->map_queue(q, ctx->cpu);
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +0100256 blk_mq_set_alloc_data(&alloc_data, q, flags, ctx, hctx);
Ming Leicb96a422014-06-01 00:43:37 +0800257 rq = __blk_mq_alloc_request(&alloc_data, rw);
258 ctx = alloc_data.ctx;
Christoph Hellwigd8525642014-05-27 20:59:50 +0200259 }
260 blk_mq_put_ctx(ctx);
Keith Buschc76541a2014-12-19 17:54:13 -0700261 if (!rq) {
Dan Williams3ef28e82015-10-21 13:20:12 -0400262 blk_queue_exit(q);
Joe Lawrencea492f072014-08-28 08:15:21 -0600263 return ERR_PTR(-EWOULDBLOCK);
Keith Buschc76541a2014-12-19 17:54:13 -0700264 }
Jens Axboe320ae512013-10-24 09:20:05 +0100265 return rq;
266}
Jens Axboe4bb659b2014-05-09 09:36:49 -0600267EXPORT_SYMBOL(blk_mq_alloc_request);
Jens Axboe320ae512013-10-24 09:20:05 +0100268
Jens Axboe320ae512013-10-24 09:20:05 +0100269static void __blk_mq_free_request(struct blk_mq_hw_ctx *hctx,
270 struct blk_mq_ctx *ctx, struct request *rq)
271{
272 const int tag = rq->tag;
273 struct request_queue *q = rq->q;
274
Jens Axboe0d2602c2014-05-13 15:10:52 -0600275 if (rq->cmd_flags & REQ_MQ_INFLIGHT)
276 atomic_dec(&hctx->nr_active);
David Hildenbrand683d0e12014-09-18 11:04:31 +0200277 rq->cmd_flags = 0;
Jens Axboe0d2602c2014-05-13 15:10:52 -0600278
Christoph Hellwigaf76e552014-05-06 12:12:45 +0200279 clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
Jens Axboe0d2602c2014-05-13 15:10:52 -0600280 blk_mq_put_tag(hctx, tag, &ctx->last_tag);
Dan Williams3ef28e82015-10-21 13:20:12 -0400281 blk_queue_exit(q);
Jens Axboe320ae512013-10-24 09:20:05 +0100282}
283
Jens Axboe7c7f2f22014-11-17 10:41:57 -0700284void blk_mq_free_hctx_request(struct blk_mq_hw_ctx *hctx, struct request *rq)
Jens Axboe320ae512013-10-24 09:20:05 +0100285{
286 struct blk_mq_ctx *ctx = rq->mq_ctx;
Jens Axboe7c7f2f22014-11-17 10:41:57 -0700287
288 ctx->rq_completed[rq_is_sync(rq)]++;
289 __blk_mq_free_request(hctx, ctx, rq);
290
291}
292EXPORT_SYMBOL_GPL(blk_mq_free_hctx_request);
293
294void blk_mq_free_request(struct request *rq)
295{
Jens Axboe320ae512013-10-24 09:20:05 +0100296 struct blk_mq_hw_ctx *hctx;
297 struct request_queue *q = rq->q;
298
Jens Axboe7c7f2f22014-11-17 10:41:57 -0700299 hctx = q->mq_ops->map_queue(q, rq->mq_ctx->cpu);
300 blk_mq_free_hctx_request(hctx, rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100301}
Jens Axboe1a3b5952014-11-17 10:40:48 -0700302EXPORT_SYMBOL_GPL(blk_mq_free_request);
Jens Axboe320ae512013-10-24 09:20:05 +0100303
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700304inline void __blk_mq_end_request(struct request *rq, int error)
Jens Axboe320ae512013-10-24 09:20:05 +0100305{
Ming Lei0d11e6a2013-12-05 10:50:39 -0700306 blk_account_io_done(rq);
307
Christoph Hellwig91b63632014-04-16 09:44:53 +0200308 if (rq->end_io) {
Jens Axboe320ae512013-10-24 09:20:05 +0100309 rq->end_io(rq, error);
Christoph Hellwig91b63632014-04-16 09:44:53 +0200310 } else {
311 if (unlikely(blk_bidi_rq(rq)))
312 blk_mq_free_request(rq->next_rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100313 blk_mq_free_request(rq);
Christoph Hellwig91b63632014-04-16 09:44:53 +0200314 }
Jens Axboe320ae512013-10-24 09:20:05 +0100315}
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700316EXPORT_SYMBOL(__blk_mq_end_request);
Christoph Hellwig63151a42014-04-16 09:44:52 +0200317
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700318void blk_mq_end_request(struct request *rq, int error)
Christoph Hellwig63151a42014-04-16 09:44:52 +0200319{
320 if (blk_update_request(rq, error, blk_rq_bytes(rq)))
321 BUG();
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700322 __blk_mq_end_request(rq, error);
Christoph Hellwig63151a42014-04-16 09:44:52 +0200323}
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700324EXPORT_SYMBOL(blk_mq_end_request);
Jens Axboe320ae512013-10-24 09:20:05 +0100325
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800326static void __blk_mq_complete_request_remote(void *data)
Jens Axboe320ae512013-10-24 09:20:05 +0100327{
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800328 struct request *rq = data;
Jens Axboe320ae512013-10-24 09:20:05 +0100329
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800330 rq->q->softirq_done_fn(rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100331}
332
Jens Axboeed851862014-05-30 21:20:50 -0600333static void blk_mq_ipi_complete_request(struct request *rq)
Jens Axboe320ae512013-10-24 09:20:05 +0100334{
335 struct blk_mq_ctx *ctx = rq->mq_ctx;
Christoph Hellwig38535202014-04-25 02:32:53 -0700336 bool shared = false;
Jens Axboe320ae512013-10-24 09:20:05 +0100337 int cpu;
338
Christoph Hellwig38535202014-04-25 02:32:53 -0700339 if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800340 rq->q->softirq_done_fn(rq);
341 return;
342 }
Jens Axboe320ae512013-10-24 09:20:05 +0100343
344 cpu = get_cpu();
Christoph Hellwig38535202014-04-25 02:32:53 -0700345 if (!test_bit(QUEUE_FLAG_SAME_FORCE, &rq->q->queue_flags))
346 shared = cpus_share_cache(cpu, ctx->cpu);
347
348 if (cpu != ctx->cpu && !shared && cpu_online(ctx->cpu)) {
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800349 rq->csd.func = __blk_mq_complete_request_remote;
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800350 rq->csd.info = rq;
351 rq->csd.flags = 0;
Frederic Weisbeckerc46fff22014-02-24 16:40:02 +0100352 smp_call_function_single_async(ctx->cpu, &rq->csd);
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800353 } else {
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800354 rq->q->softirq_done_fn(rq);
Christoph Hellwig3d6efbf2014-01-08 09:33:37 -0800355 }
Jens Axboe320ae512013-10-24 09:20:05 +0100356 put_cpu();
357}
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800358
Jens Axboe1fa8cc52015-11-05 14:32:55 -0700359static void __blk_mq_complete_request(struct request *rq)
Jens Axboeed851862014-05-30 21:20:50 -0600360{
361 struct request_queue *q = rq->q;
362
363 if (!q->softirq_done_fn)
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700364 blk_mq_end_request(rq, rq->errors);
Jens Axboeed851862014-05-30 21:20:50 -0600365 else
366 blk_mq_ipi_complete_request(rq);
367}
368
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800369/**
370 * blk_mq_complete_request - end I/O on a request
371 * @rq: the request being processed
372 *
373 * Description:
374 * Ends all I/O on a request. It does not handle partial completions.
375 * The actual completion happens out-of-order, through a IPI handler.
376 **/
Christoph Hellwigf4829a92015-09-27 21:01:50 +0200377void blk_mq_complete_request(struct request *rq, int error)
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800378{
Jens Axboe95f09682014-05-27 17:46:48 -0600379 struct request_queue *q = rq->q;
380
381 if (unlikely(blk_should_fake_timeout(q)))
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800382 return;
Christoph Hellwigf4829a92015-09-27 21:01:50 +0200383 if (!blk_mark_rq_complete(rq)) {
384 rq->errors = error;
Jens Axboeed851862014-05-30 21:20:50 -0600385 __blk_mq_complete_request(rq);
Christoph Hellwigf4829a92015-09-27 21:01:50 +0200386 }
Christoph Hellwig30a91cb2014-02-10 03:24:38 -0800387}
388EXPORT_SYMBOL(blk_mq_complete_request);
Jens Axboe320ae512013-10-24 09:20:05 +0100389
Keith Busch973c0192015-01-07 18:55:43 -0700390int blk_mq_request_started(struct request *rq)
391{
392 return test_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
393}
394EXPORT_SYMBOL_GPL(blk_mq_request_started);
395
Christoph Hellwige2490072014-09-13 16:40:09 -0700396void blk_mq_start_request(struct request *rq)
Jens Axboe320ae512013-10-24 09:20:05 +0100397{
398 struct request_queue *q = rq->q;
399
400 trace_block_rq_issue(q, rq);
401
Christoph Hellwig742ee692014-04-14 10:30:06 +0200402 rq->resid_len = blk_rq_bytes(rq);
Christoph Hellwig91b63632014-04-16 09:44:53 +0200403 if (unlikely(blk_bidi_rq(rq)))
404 rq->next_rq->resid_len = blk_rq_bytes(rq->next_rq);
Christoph Hellwig742ee692014-04-14 10:30:06 +0200405
Ming Lei2b8393b2014-06-10 00:16:41 +0800406 blk_add_timer(rq);
Jens Axboe87ee7b12014-04-24 08:51:47 -0600407
408 /*
Jens Axboe538b7532014-09-16 10:37:37 -0600409 * Ensure that ->deadline is visible before set the started
410 * flag and clear the completed flag.
411 */
412 smp_mb__before_atomic();
413
414 /*
Jens Axboe87ee7b12014-04-24 08:51:47 -0600415 * Mark us as started and clear complete. Complete might have been
416 * set if requeue raced with timeout, which then marked it as
417 * complete. So be sure to clear complete again when we start
418 * the request, otherwise we'll ignore the completion event.
419 */
Jens Axboe4b570522014-05-29 11:00:11 -0600420 if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags))
421 set_bit(REQ_ATOM_STARTED, &rq->atomic_flags);
422 if (test_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags))
423 clear_bit(REQ_ATOM_COMPLETE, &rq->atomic_flags);
Christoph Hellwig49f5baa2014-02-11 08:27:14 -0800424
425 if (q->dma_drain_size && blk_rq_bytes(rq)) {
426 /*
427 * Make sure space for the drain appears. We know we can do
428 * this because max_hw_segments has been adjusted to be one
429 * fewer than the device can handle.
430 */
431 rq->nr_phys_segments++;
432 }
Jens Axboe320ae512013-10-24 09:20:05 +0100433}
Christoph Hellwige2490072014-09-13 16:40:09 -0700434EXPORT_SYMBOL(blk_mq_start_request);
Jens Axboe320ae512013-10-24 09:20:05 +0100435
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200436static void __blk_mq_requeue_request(struct request *rq)
Jens Axboe320ae512013-10-24 09:20:05 +0100437{
438 struct request_queue *q = rq->q;
439
440 trace_block_rq_requeue(q, rq);
Christoph Hellwig49f5baa2014-02-11 08:27:14 -0800441
Christoph Hellwige2490072014-09-13 16:40:09 -0700442 if (test_and_clear_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
443 if (q->dma_drain_size && blk_rq_bytes(rq))
444 rq->nr_phys_segments--;
445 }
Jens Axboe320ae512013-10-24 09:20:05 +0100446}
447
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200448void blk_mq_requeue_request(struct request *rq)
449{
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200450 __blk_mq_requeue_request(rq);
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200451
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200452 BUG_ON(blk_queued_rq(rq));
Christoph Hellwig6fca6a62014-05-28 08:08:02 -0600453 blk_mq_add_to_requeue_list(rq, true);
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200454}
455EXPORT_SYMBOL(blk_mq_requeue_request);
456
Christoph Hellwig6fca6a62014-05-28 08:08:02 -0600457static void blk_mq_requeue_work(struct work_struct *work)
458{
459 struct request_queue *q =
460 container_of(work, struct request_queue, requeue_work);
461 LIST_HEAD(rq_list);
462 struct request *rq, *next;
463 unsigned long flags;
464
465 spin_lock_irqsave(&q->requeue_lock, flags);
466 list_splice_init(&q->requeue_list, &rq_list);
467 spin_unlock_irqrestore(&q->requeue_lock, flags);
468
469 list_for_each_entry_safe(rq, next, &rq_list, queuelist) {
470 if (!(rq->cmd_flags & REQ_SOFTBARRIER))
471 continue;
472
473 rq->cmd_flags &= ~REQ_SOFTBARRIER;
474 list_del_init(&rq->queuelist);
475 blk_mq_insert_request(rq, true, false, false);
476 }
477
478 while (!list_empty(&rq_list)) {
479 rq = list_entry(rq_list.next, struct request, queuelist);
480 list_del_init(&rq->queuelist);
481 blk_mq_insert_request(rq, false, false, false);
482 }
483
Jens Axboe8b957412014-09-19 13:10:29 -0600484 /*
485 * Use the start variant of queue running here, so that running
486 * the requeue work will kick stopped queues.
487 */
488 blk_mq_start_hw_queues(q);
Christoph Hellwig6fca6a62014-05-28 08:08:02 -0600489}
490
491void blk_mq_add_to_requeue_list(struct request *rq, bool at_head)
492{
493 struct request_queue *q = rq->q;
494 unsigned long flags;
495
496 /*
497 * We abuse this flag that is otherwise used by the I/O scheduler to
498 * request head insertation from the workqueue.
499 */
500 BUG_ON(rq->cmd_flags & REQ_SOFTBARRIER);
501
502 spin_lock_irqsave(&q->requeue_lock, flags);
503 if (at_head) {
504 rq->cmd_flags |= REQ_SOFTBARRIER;
505 list_add(&rq->queuelist, &q->requeue_list);
506 } else {
507 list_add_tail(&rq->queuelist, &q->requeue_list);
508 }
509 spin_unlock_irqrestore(&q->requeue_lock, flags);
510}
511EXPORT_SYMBOL(blk_mq_add_to_requeue_list);
512
Keith Buschc68ed592015-01-07 18:55:44 -0700513void blk_mq_cancel_requeue_work(struct request_queue *q)
514{
515 cancel_work_sync(&q->requeue_work);
516}
517EXPORT_SYMBOL_GPL(blk_mq_cancel_requeue_work);
518
Christoph Hellwig6fca6a62014-05-28 08:08:02 -0600519void blk_mq_kick_requeue_list(struct request_queue *q)
520{
521 kblockd_schedule_work(&q->requeue_work);
522}
523EXPORT_SYMBOL(blk_mq_kick_requeue_list);
524
Jens Axboe1885b242015-01-07 18:55:45 -0700525void blk_mq_abort_requeue_list(struct request_queue *q)
526{
527 unsigned long flags;
528 LIST_HEAD(rq_list);
529
530 spin_lock_irqsave(&q->requeue_lock, flags);
531 list_splice_init(&q->requeue_list, &rq_list);
532 spin_unlock_irqrestore(&q->requeue_lock, flags);
533
534 while (!list_empty(&rq_list)) {
535 struct request *rq;
536
537 rq = list_first_entry(&rq_list, struct request, queuelist);
538 list_del_init(&rq->queuelist);
539 rq->errors = -EIO;
540 blk_mq_end_request(rq, rq->errors);
541 }
542}
543EXPORT_SYMBOL(blk_mq_abort_requeue_list);
544
Jens Axboe0e62f512014-06-04 10:23:49 -0600545struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags, unsigned int tag)
546{
Hannes Reinecke4ee86ba2016-03-15 12:03:28 -0700547 if (tag < tags->nr_tags)
548 return tags->rqs[tag];
549
550 return NULL;
Christoph Hellwig24d2f902014-04-15 14:14:00 -0600551}
552EXPORT_SYMBOL(blk_mq_tag_to_rq);
553
Jens Axboe320ae512013-10-24 09:20:05 +0100554struct blk_mq_timeout_data {
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700555 unsigned long next;
556 unsigned int next_set;
Jens Axboe320ae512013-10-24 09:20:05 +0100557};
558
Christoph Hellwig90415832014-09-22 10:21:48 -0600559void blk_mq_rq_timed_out(struct request *req, bool reserved)
Jens Axboe320ae512013-10-24 09:20:05 +0100560{
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700561 struct blk_mq_ops *ops = req->q->mq_ops;
562 enum blk_eh_timer_return ret = BLK_EH_RESET_TIMER;
Jens Axboe87ee7b12014-04-24 08:51:47 -0600563
564 /*
565 * We know that complete is set at this point. If STARTED isn't set
566 * anymore, then the request isn't active and the "timeout" should
567 * just be ignored. This can happen due to the bitflag ordering.
568 * Timeout first checks if STARTED is set, and if it is, assumes
569 * the request is active. But if we race with completion, then
570 * we both flags will get cleared. So check here again, and ignore
571 * a timeout event with a request that isn't active.
572 */
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700573 if (!test_bit(REQ_ATOM_STARTED, &req->atomic_flags))
574 return;
Jens Axboe87ee7b12014-04-24 08:51:47 -0600575
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700576 if (ops->timeout)
Christoph Hellwig0152fb62014-09-13 16:40:13 -0700577 ret = ops->timeout(req, reserved);
Jens Axboe87ee7b12014-04-24 08:51:47 -0600578
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700579 switch (ret) {
580 case BLK_EH_HANDLED:
581 __blk_mq_complete_request(req);
582 break;
583 case BLK_EH_RESET_TIMER:
584 blk_add_timer(req);
585 blk_clear_rq_complete(req);
586 break;
587 case BLK_EH_NOT_HANDLED:
588 break;
589 default:
590 printk(KERN_ERR "block: bad eh return: %d\n", ret);
591 break;
592 }
Jens Axboe87ee7b12014-04-24 08:51:47 -0600593}
Keith Busch5b3f25f2015-01-07 18:55:46 -0700594
Christoph Hellwig81481eb2014-09-13 16:40:11 -0700595static void blk_mq_check_expired(struct blk_mq_hw_ctx *hctx,
596 struct request *rq, void *priv, bool reserved)
Jens Axboe320ae512013-10-24 09:20:05 +0100597{
Christoph Hellwig81481eb2014-09-13 16:40:11 -0700598 struct blk_mq_timeout_data *data = priv;
599
Keith Buscheb130db2015-01-08 08:59:53 -0700600 if (!test_bit(REQ_ATOM_STARTED, &rq->atomic_flags)) {
601 /*
602 * If a request wasn't started before the queue was
603 * marked dying, kill it here or it'll go unnoticed.
604 */
Keith Buscha59e0f52016-02-11 13:05:38 -0700605 if (unlikely(blk_queue_dying(rq->q))) {
606 rq->errors = -EIO;
607 blk_mq_end_request(rq, rq->errors);
608 }
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700609 return;
Keith Buscheb130db2015-01-08 08:59:53 -0700610 }
Jens Axboe320ae512013-10-24 09:20:05 +0100611
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700612 if (time_after_eq(jiffies, rq->deadline)) {
613 if (!blk_mark_rq_complete(rq))
Christoph Hellwig0152fb62014-09-13 16:40:13 -0700614 blk_mq_rq_timed_out(rq, reserved);
Christoph Hellwig46f92d42014-09-13 16:40:12 -0700615 } else if (!data->next_set || time_after(data->next, rq->deadline)) {
616 data->next = rq->deadline;
617 data->next_set = 1;
618 }
Jens Axboe320ae512013-10-24 09:20:05 +0100619}
620
Christoph Hellwig287922e2015-10-30 20:57:30 +0800621static void blk_mq_timeout_work(struct work_struct *work)
Jens Axboe320ae512013-10-24 09:20:05 +0100622{
Christoph Hellwig287922e2015-10-30 20:57:30 +0800623 struct request_queue *q =
624 container_of(work, struct request_queue, timeout_work);
Christoph Hellwig81481eb2014-09-13 16:40:11 -0700625 struct blk_mq_timeout_data data = {
626 .next = 0,
627 .next_set = 0,
628 };
Christoph Hellwig81481eb2014-09-13 16:40:11 -0700629 int i;
Jens Axboe320ae512013-10-24 09:20:05 +0100630
Christoph Hellwig287922e2015-10-30 20:57:30 +0800631 if (blk_queue_enter(q, true))
632 return;
633
Christoph Hellwig0bf6cd52015-09-27 21:01:51 +0200634 blk_mq_queue_tag_busy_iter(q, blk_mq_check_expired, &data);
Jens Axboe320ae512013-10-24 09:20:05 +0100635
Christoph Hellwig81481eb2014-09-13 16:40:11 -0700636 if (data.next_set) {
637 data.next = blk_rq_timeout(round_jiffies_up(data.next));
638 mod_timer(&q->timeout, data.next);
Jens Axboe0d2602c2014-05-13 15:10:52 -0600639 } else {
Christoph Hellwig0bf6cd52015-09-27 21:01:51 +0200640 struct blk_mq_hw_ctx *hctx;
641
Ming Leif054b562015-04-21 10:00:19 +0800642 queue_for_each_hw_ctx(q, hctx, i) {
643 /* the hctx may be unmapped, so check it here */
644 if (blk_mq_hw_queue_mapped(hctx))
645 blk_mq_tag_idle(hctx);
646 }
Jens Axboe0d2602c2014-05-13 15:10:52 -0600647 }
Christoph Hellwig287922e2015-10-30 20:57:30 +0800648 blk_queue_exit(q);
Jens Axboe320ae512013-10-24 09:20:05 +0100649}
650
651/*
652 * Reverse check our software queue for entries that we could potentially
653 * merge with. Currently includes a hand-wavy stop count of 8, to not spend
654 * too much time checking for merges.
655 */
656static bool blk_mq_attempt_merge(struct request_queue *q,
657 struct blk_mq_ctx *ctx, struct bio *bio)
658{
659 struct request *rq;
660 int checked = 8;
661
662 list_for_each_entry_reverse(rq, &ctx->rq_list, queuelist) {
663 int el_ret;
664
665 if (!checked--)
666 break;
667
668 if (!blk_rq_merge_ok(rq, bio))
669 continue;
670
671 el_ret = blk_try_merge(rq, bio);
672 if (el_ret == ELEVATOR_BACK_MERGE) {
673 if (bio_attempt_back_merge(q, rq, bio)) {
674 ctx->rq_merged++;
675 return true;
676 }
677 break;
678 } else if (el_ret == ELEVATOR_FRONT_MERGE) {
679 if (bio_attempt_front_merge(q, rq, bio)) {
680 ctx->rq_merged++;
681 return true;
682 }
683 break;
684 }
685 }
686
687 return false;
688}
689
Jens Axboe320ae512013-10-24 09:20:05 +0100690/*
Jens Axboe1429d7c2014-05-19 09:23:55 -0600691 * Process software queues that have been marked busy, splicing them
692 * to the for-dispatch
693 */
694static void flush_busy_ctxs(struct blk_mq_hw_ctx *hctx, struct list_head *list)
695{
696 struct blk_mq_ctx *ctx;
697 int i;
698
Jens Axboe569fd0c2015-04-17 08:28:50 -0600699 for (i = 0; i < hctx->ctx_map.size; i++) {
Jens Axboe1429d7c2014-05-19 09:23:55 -0600700 struct blk_align_bitmap *bm = &hctx->ctx_map.map[i];
701 unsigned int off, bit;
702
703 if (!bm->word)
704 continue;
705
706 bit = 0;
707 off = i * hctx->ctx_map.bits_per_word;
708 do {
709 bit = find_next_bit(&bm->word, bm->depth, bit);
710 if (bit >= bm->depth)
711 break;
712
713 ctx = hctx->ctxs[bit + off];
714 clear_bit(bit, &bm->word);
715 spin_lock(&ctx->lock);
716 list_splice_tail_init(&ctx->rq_list, list);
717 spin_unlock(&ctx->lock);
718
719 bit++;
720 } while (1);
721 }
722}
723
724/*
Jens Axboe320ae512013-10-24 09:20:05 +0100725 * Run this hardware queue, pulling any software queues mapped to it in.
726 * Note that this function currently has various problems around ordering
727 * of IO. In particular, we'd like FIFO behaviour on handling existing
728 * items on the hctx->dispatch list. Ignore that for now.
729 */
730static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx)
731{
732 struct request_queue *q = hctx->queue;
Jens Axboe320ae512013-10-24 09:20:05 +0100733 struct request *rq;
734 LIST_HEAD(rq_list);
Jens Axboe74c45052014-10-29 11:14:52 -0600735 LIST_HEAD(driver_list);
736 struct list_head *dptr;
Jens Axboe1429d7c2014-05-19 09:23:55 -0600737 int queued;
Jens Axboe320ae512013-10-24 09:20:05 +0100738
Jens Axboefd1270d2014-04-16 09:23:48 -0600739 WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx->cpumask));
Jens Axboee4043dc2014-04-09 10:18:23 -0600740
Jens Axboe5d12f902014-03-19 15:25:02 -0600741 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
Jens Axboe320ae512013-10-24 09:20:05 +0100742 return;
743
744 hctx->run++;
745
746 /*
747 * Touch any software queue that has pending entries.
748 */
Jens Axboe1429d7c2014-05-19 09:23:55 -0600749 flush_busy_ctxs(hctx, &rq_list);
Jens Axboe320ae512013-10-24 09:20:05 +0100750
751 /*
752 * If we have previous entries on our dispatch list, grab them
753 * and stuff them at the front for more fair dispatch.
754 */
755 if (!list_empty_careful(&hctx->dispatch)) {
756 spin_lock(&hctx->lock);
757 if (!list_empty(&hctx->dispatch))
758 list_splice_init(&hctx->dispatch, &rq_list);
759 spin_unlock(&hctx->lock);
760 }
761
762 /*
Jens Axboe74c45052014-10-29 11:14:52 -0600763 * Start off with dptr being NULL, so we start the first request
764 * immediately, even if we have more pending.
765 */
766 dptr = NULL;
767
768 /*
Jens Axboe320ae512013-10-24 09:20:05 +0100769 * Now process all the entries, sending them to the driver.
770 */
Jens Axboe1429d7c2014-05-19 09:23:55 -0600771 queued = 0;
Jens Axboe320ae512013-10-24 09:20:05 +0100772 while (!list_empty(&rq_list)) {
Jens Axboe74c45052014-10-29 11:14:52 -0600773 struct blk_mq_queue_data bd;
Jens Axboe320ae512013-10-24 09:20:05 +0100774 int ret;
775
776 rq = list_first_entry(&rq_list, struct request, queuelist);
777 list_del_init(&rq->queuelist);
Jens Axboe320ae512013-10-24 09:20:05 +0100778
Jens Axboe74c45052014-10-29 11:14:52 -0600779 bd.rq = rq;
780 bd.list = dptr;
781 bd.last = list_empty(&rq_list);
782
783 ret = q->mq_ops->queue_rq(hctx, &bd);
Jens Axboe320ae512013-10-24 09:20:05 +0100784 switch (ret) {
785 case BLK_MQ_RQ_QUEUE_OK:
786 queued++;
787 continue;
788 case BLK_MQ_RQ_QUEUE_BUSY:
Jens Axboe320ae512013-10-24 09:20:05 +0100789 list_add(&rq->queuelist, &rq_list);
Christoph Hellwiged0791b2014-04-16 09:44:57 +0200790 __blk_mq_requeue_request(rq);
Jens Axboe320ae512013-10-24 09:20:05 +0100791 break;
792 default:
793 pr_err("blk-mq: bad return on queue: %d\n", ret);
Jens Axboe320ae512013-10-24 09:20:05 +0100794 case BLK_MQ_RQ_QUEUE_ERROR:
Christoph Hellwig1e93b8c2014-02-11 08:27:13 -0800795 rq->errors = -EIO;
Christoph Hellwigc8a446a2014-09-13 16:40:10 -0700796 blk_mq_end_request(rq, rq->errors);
Jens Axboe320ae512013-10-24 09:20:05 +0100797 break;
798 }
799
800 if (ret == BLK_MQ_RQ_QUEUE_BUSY)
801 break;
Jens Axboe74c45052014-10-29 11:14:52 -0600802
803 /*
804 * We've done the first request. If we have more than 1
805 * left in the list, set dptr to defer issue.
806 */
807 if (!dptr && rq_list.next != rq_list.prev)
808 dptr = &driver_list;
Jens Axboe320ae512013-10-24 09:20:05 +0100809 }
810
811 if (!queued)
812 hctx->dispatched[0]++;
813 else if (queued < (1 << (BLK_MQ_MAX_DISPATCH_ORDER - 1)))
814 hctx->dispatched[ilog2(queued) + 1]++;
815
816 /*
817 * Any items that need requeuing? Stuff them into hctx->dispatch,
818 * that is where we will continue on next queue run.
819 */
820 if (!list_empty(&rq_list)) {
821 spin_lock(&hctx->lock);
822 list_splice(&rq_list, &hctx->dispatch);
823 spin_unlock(&hctx->lock);
Shaohua Li9ba52e52015-05-04 14:32:48 -0600824 /*
825 * the queue is expected stopped with BLK_MQ_RQ_QUEUE_BUSY, but
826 * it's possible the queue is stopped and restarted again
827 * before this. Queue restart will dispatch requests. And since
828 * requests in rq_list aren't added into hctx->dispatch yet,
829 * the requests in rq_list might get lost.
830 *
831 * blk_mq_run_hw_queue() already checks the STOPPED bit
832 **/
833 blk_mq_run_hw_queue(hctx, true);
Jens Axboe320ae512013-10-24 09:20:05 +0100834 }
835}
836
Jens Axboe506e9312014-05-07 10:26:44 -0600837/*
838 * It'd be great if the workqueue API had a way to pass
839 * in a mask and had some smarts for more clever placement.
840 * For now we just round-robin here, switching for every
841 * BLK_MQ_CPU_WORK_BATCH queued items.
842 */
843static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx *hctx)
844{
Christoph Hellwigb657d7e2014-11-24 09:27:23 +0100845 if (hctx->queue->nr_hw_queues == 1)
846 return WORK_CPU_UNBOUND;
Jens Axboe506e9312014-05-07 10:26:44 -0600847
848 if (--hctx->next_cpu_batch <= 0) {
Christoph Hellwigb657d7e2014-11-24 09:27:23 +0100849 int cpu = hctx->next_cpu, next_cpu;
Jens Axboe506e9312014-05-07 10:26:44 -0600850
851 next_cpu = cpumask_next(hctx->next_cpu, hctx->cpumask);
852 if (next_cpu >= nr_cpu_ids)
853 next_cpu = cpumask_first(hctx->cpumask);
854
855 hctx->next_cpu = next_cpu;
856 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
Christoph Hellwigb657d7e2014-11-24 09:27:23 +0100857
858 return cpu;
Jens Axboe506e9312014-05-07 10:26:44 -0600859 }
860
Christoph Hellwigb657d7e2014-11-24 09:27:23 +0100861 return hctx->next_cpu;
Jens Axboe506e9312014-05-07 10:26:44 -0600862}
863
Jens Axboe320ae512013-10-24 09:20:05 +0100864void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async)
865{
Ming Lei19c66e52014-12-03 19:38:04 +0800866 if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state) ||
867 !blk_mq_hw_queue_mapped(hctx)))
Jens Axboe320ae512013-10-24 09:20:05 +0100868 return;
869
Paolo Bonzini398205b2014-11-07 23:03:59 +0100870 if (!async) {
Paolo Bonzini2a90d4a2014-11-07 23:04:00 +0100871 int cpu = get_cpu();
872 if (cpumask_test_cpu(cpu, hctx->cpumask)) {
Paolo Bonzini398205b2014-11-07 23:03:59 +0100873 __blk_mq_run_hw_queue(hctx);
Paolo Bonzini2a90d4a2014-11-07 23:04:00 +0100874 put_cpu();
Paolo Bonzini398205b2014-11-07 23:03:59 +0100875 return;
876 }
Jens Axboee4043dc2014-04-09 10:18:23 -0600877
Paolo Bonzini2a90d4a2014-11-07 23:04:00 +0100878 put_cpu();
Jens Axboee4043dc2014-04-09 10:18:23 -0600879 }
Paolo Bonzini398205b2014-11-07 23:03:59 +0100880
Christoph Hellwigb657d7e2014-11-24 09:27:23 +0100881 kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
882 &hctx->run_work, 0);
Jens Axboe320ae512013-10-24 09:20:05 +0100883}
884
Mike Snitzerb94ec292015-03-11 23:56:38 -0400885void blk_mq_run_hw_queues(struct request_queue *q, bool async)
Jens Axboe320ae512013-10-24 09:20:05 +0100886{
887 struct blk_mq_hw_ctx *hctx;
888 int i;
889
890 queue_for_each_hw_ctx(q, hctx, i) {
891 if ((!blk_mq_hctx_has_pending(hctx) &&
892 list_empty_careful(&hctx->dispatch)) ||
Jens Axboe5d12f902014-03-19 15:25:02 -0600893 test_bit(BLK_MQ_S_STOPPED, &hctx->state))
Jens Axboe320ae512013-10-24 09:20:05 +0100894 continue;
895
Mike Snitzerb94ec292015-03-11 23:56:38 -0400896 blk_mq_run_hw_queue(hctx, async);
Jens Axboe320ae512013-10-24 09:20:05 +0100897 }
898}
Mike Snitzerb94ec292015-03-11 23:56:38 -0400899EXPORT_SYMBOL(blk_mq_run_hw_queues);
Jens Axboe320ae512013-10-24 09:20:05 +0100900
901void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx)
902{
Christoph Hellwig70f4db62014-04-16 10:48:08 -0600903 cancel_delayed_work(&hctx->run_work);
904 cancel_delayed_work(&hctx->delay_work);
Jens Axboe320ae512013-10-24 09:20:05 +0100905 set_bit(BLK_MQ_S_STOPPED, &hctx->state);
906}
907EXPORT_SYMBOL(blk_mq_stop_hw_queue);
908
Christoph Hellwig280d45f2013-10-25 14:45:58 +0100909void blk_mq_stop_hw_queues(struct request_queue *q)
910{
911 struct blk_mq_hw_ctx *hctx;
912 int i;
913
914 queue_for_each_hw_ctx(q, hctx, i)
915 blk_mq_stop_hw_queue(hctx);
916}
917EXPORT_SYMBOL(blk_mq_stop_hw_queues);
918
Jens Axboe320ae512013-10-24 09:20:05 +0100919void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx)
920{
921 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
Jens Axboee4043dc2014-04-09 10:18:23 -0600922
Jens Axboe0ffbce82014-06-25 08:22:34 -0600923 blk_mq_run_hw_queue(hctx, false);
Jens Axboe320ae512013-10-24 09:20:05 +0100924}
925EXPORT_SYMBOL(blk_mq_start_hw_queue);
926
Christoph Hellwig2f268552014-04-16 09:44:56 +0200927void blk_mq_start_hw_queues(struct request_queue *q)
928{
929 struct blk_mq_hw_ctx *hctx;
930 int i;
931
932 queue_for_each_hw_ctx(q, hctx, i)
933 blk_mq_start_hw_queue(hctx);
934}
935EXPORT_SYMBOL(blk_mq_start_hw_queues);
936
Christoph Hellwig1b4a3252014-04-16 09:44:54 +0200937void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async)
Jens Axboe320ae512013-10-24 09:20:05 +0100938{
939 struct blk_mq_hw_ctx *hctx;
940 int i;
941
942 queue_for_each_hw_ctx(q, hctx, i) {
943 if (!test_bit(BLK_MQ_S_STOPPED, &hctx->state))
944 continue;
945
946 clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
Christoph Hellwig1b4a3252014-04-16 09:44:54 +0200947 blk_mq_run_hw_queue(hctx, async);
Jens Axboe320ae512013-10-24 09:20:05 +0100948 }
949}
950EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues);
951
Christoph Hellwig70f4db62014-04-16 10:48:08 -0600952static void blk_mq_run_work_fn(struct work_struct *work)
Jens Axboe320ae512013-10-24 09:20:05 +0100953{
954 struct blk_mq_hw_ctx *hctx;
955
Christoph Hellwig70f4db62014-04-16 10:48:08 -0600956 hctx = container_of(work, struct blk_mq_hw_ctx, run_work.work);
Jens Axboee4043dc2014-04-09 10:18:23 -0600957
Jens Axboe320ae512013-10-24 09:20:05 +0100958 __blk_mq_run_hw_queue(hctx);
959}
960
Christoph Hellwig70f4db62014-04-16 10:48:08 -0600961static void blk_mq_delay_work_fn(struct work_struct *work)
962{
963 struct blk_mq_hw_ctx *hctx;
964
965 hctx = container_of(work, struct blk_mq_hw_ctx, delay_work.work);
966
967 if (test_and_clear_bit(BLK_MQ_S_STOPPED, &hctx->state))
968 __blk_mq_run_hw_queue(hctx);
969}
970
971void blk_mq_delay_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs)
972{
Ming Lei19c66e52014-12-03 19:38:04 +0800973 if (unlikely(!blk_mq_hw_queue_mapped(hctx)))
974 return;
Christoph Hellwig70f4db62014-04-16 10:48:08 -0600975
Christoph Hellwigb657d7e2014-11-24 09:27:23 +0100976 kblockd_schedule_delayed_work_on(blk_mq_hctx_next_cpu(hctx),
977 &hctx->delay_work, msecs_to_jiffies(msecs));
Christoph Hellwig70f4db62014-04-16 10:48:08 -0600978}
979EXPORT_SYMBOL(blk_mq_delay_queue);
980
Ming Leicfd0c552015-10-20 23:13:57 +0800981static inline void __blk_mq_insert_req_list(struct blk_mq_hw_ctx *hctx,
982 struct blk_mq_ctx *ctx,
983 struct request *rq,
984 bool at_head)
Jens Axboe320ae512013-10-24 09:20:05 +0100985{
Jens Axboe01b983c2013-11-19 18:59:10 -0700986 trace_block_rq_insert(hctx->queue, rq);
987
Christoph Hellwig72a0a362014-02-07 10:22:36 -0800988 if (at_head)
989 list_add(&rq->queuelist, &ctx->rq_list);
990 else
991 list_add_tail(&rq->queuelist, &ctx->rq_list);
Ming Leicfd0c552015-10-20 23:13:57 +0800992}
Jens Axboe4bb659b2014-05-09 09:36:49 -0600993
Ming Leicfd0c552015-10-20 23:13:57 +0800994static void __blk_mq_insert_request(struct blk_mq_hw_ctx *hctx,
995 struct request *rq, bool at_head)
996{
997 struct blk_mq_ctx *ctx = rq->mq_ctx;
998
999 __blk_mq_insert_req_list(hctx, ctx, rq, at_head);
Jens Axboe320ae512013-10-24 09:20:05 +01001000 blk_mq_hctx_mark_pending(hctx, ctx);
Jens Axboe320ae512013-10-24 09:20:05 +01001001}
1002
Christoph Hellwigeeabc852014-03-21 08:57:37 -06001003void blk_mq_insert_request(struct request *rq, bool at_head, bool run_queue,
1004 bool async)
Jens Axboe320ae512013-10-24 09:20:05 +01001005{
1006 struct request_queue *q = rq->q;
1007 struct blk_mq_hw_ctx *hctx;
Christoph Hellwigeeabc852014-03-21 08:57:37 -06001008 struct blk_mq_ctx *ctx = rq->mq_ctx, *current_ctx;
Jens Axboe320ae512013-10-24 09:20:05 +01001009
1010 current_ctx = blk_mq_get_ctx(q);
Christoph Hellwigeeabc852014-03-21 08:57:37 -06001011 if (!cpu_online(ctx->cpu))
1012 rq->mq_ctx = ctx = current_ctx;
Jens Axboe320ae512013-10-24 09:20:05 +01001013
Jens Axboe320ae512013-10-24 09:20:05 +01001014 hctx = q->mq_ops->map_queue(q, ctx->cpu);
1015
Christoph Hellwiga57a1782014-09-16 14:44:07 -07001016 spin_lock(&ctx->lock);
1017 __blk_mq_insert_request(hctx, rq, at_head);
1018 spin_unlock(&ctx->lock);
Jens Axboe320ae512013-10-24 09:20:05 +01001019
Jens Axboe320ae512013-10-24 09:20:05 +01001020 if (run_queue)
1021 blk_mq_run_hw_queue(hctx, async);
Jens Axboee4043dc2014-04-09 10:18:23 -06001022
1023 blk_mq_put_ctx(current_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +01001024}
1025
1026static void blk_mq_insert_requests(struct request_queue *q,
1027 struct blk_mq_ctx *ctx,
1028 struct list_head *list,
1029 int depth,
1030 bool from_schedule)
1031
1032{
1033 struct blk_mq_hw_ctx *hctx;
1034 struct blk_mq_ctx *current_ctx;
1035
1036 trace_block_unplug(q, depth, !from_schedule);
1037
1038 current_ctx = blk_mq_get_ctx(q);
1039
1040 if (!cpu_online(ctx->cpu))
1041 ctx = current_ctx;
1042 hctx = q->mq_ops->map_queue(q, ctx->cpu);
1043
1044 /*
1045 * preemption doesn't flush plug list, so it's possible ctx->cpu is
1046 * offline now
1047 */
1048 spin_lock(&ctx->lock);
1049 while (!list_empty(list)) {
1050 struct request *rq;
1051
1052 rq = list_first_entry(list, struct request, queuelist);
1053 list_del_init(&rq->queuelist);
1054 rq->mq_ctx = ctx;
Ming Leicfd0c552015-10-20 23:13:57 +08001055 __blk_mq_insert_req_list(hctx, ctx, rq, false);
Jens Axboe320ae512013-10-24 09:20:05 +01001056 }
Ming Leicfd0c552015-10-20 23:13:57 +08001057 blk_mq_hctx_mark_pending(hctx, ctx);
Jens Axboe320ae512013-10-24 09:20:05 +01001058 spin_unlock(&ctx->lock);
1059
Jens Axboe320ae512013-10-24 09:20:05 +01001060 blk_mq_run_hw_queue(hctx, from_schedule);
Jens Axboee4043dc2014-04-09 10:18:23 -06001061 blk_mq_put_ctx(current_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +01001062}
1063
1064static int plug_ctx_cmp(void *priv, struct list_head *a, struct list_head *b)
1065{
1066 struct request *rqa = container_of(a, struct request, queuelist);
1067 struct request *rqb = container_of(b, struct request, queuelist);
1068
1069 return !(rqa->mq_ctx < rqb->mq_ctx ||
1070 (rqa->mq_ctx == rqb->mq_ctx &&
1071 blk_rq_pos(rqa) < blk_rq_pos(rqb)));
1072}
1073
1074void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
1075{
1076 struct blk_mq_ctx *this_ctx;
1077 struct request_queue *this_q;
1078 struct request *rq;
1079 LIST_HEAD(list);
1080 LIST_HEAD(ctx_list);
1081 unsigned int depth;
1082
1083 list_splice_init(&plug->mq_list, &list);
1084
1085 list_sort(NULL, &list, plug_ctx_cmp);
1086
1087 this_q = NULL;
1088 this_ctx = NULL;
1089 depth = 0;
1090
1091 while (!list_empty(&list)) {
1092 rq = list_entry_rq(list.next);
1093 list_del_init(&rq->queuelist);
1094 BUG_ON(!rq->q);
1095 if (rq->mq_ctx != this_ctx) {
1096 if (this_ctx) {
1097 blk_mq_insert_requests(this_q, this_ctx,
1098 &ctx_list, depth,
1099 from_schedule);
1100 }
1101
1102 this_ctx = rq->mq_ctx;
1103 this_q = rq->q;
1104 depth = 0;
1105 }
1106
1107 depth++;
1108 list_add_tail(&rq->queuelist, &ctx_list);
1109 }
1110
1111 /*
1112 * If 'this_ctx' is set, we know we have entries to complete
1113 * on 'ctx_list'. Do those.
1114 */
1115 if (this_ctx) {
1116 blk_mq_insert_requests(this_q, this_ctx, &ctx_list, depth,
1117 from_schedule);
1118 }
1119}
1120
1121static void blk_mq_bio_to_request(struct request *rq, struct bio *bio)
1122{
1123 init_request_from_bio(rq, bio);
Jens Axboe4b570522014-05-29 11:00:11 -06001124
Michael Callahana21f2a32016-05-03 11:12:49 -04001125 blk_account_io_start(rq, 1);
Jens Axboe320ae512013-10-24 09:20:05 +01001126}
1127
Jens Axboe274a5842014-08-15 12:44:08 -06001128static inline bool hctx_allow_merges(struct blk_mq_hw_ctx *hctx)
1129{
1130 return (hctx->flags & BLK_MQ_F_SHOULD_MERGE) &&
1131 !blk_queue_nomerges(hctx->queue);
1132}
1133
Jens Axboe07068d52014-05-22 10:40:51 -06001134static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
1135 struct blk_mq_ctx *ctx,
1136 struct request *rq, struct bio *bio)
1137{
Ming Leie18378a2015-10-20 23:13:54 +08001138 if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
Jens Axboe07068d52014-05-22 10:40:51 -06001139 blk_mq_bio_to_request(rq, bio);
1140 spin_lock(&ctx->lock);
1141insert_rq:
1142 __blk_mq_insert_request(hctx, rq, false);
1143 spin_unlock(&ctx->lock);
1144 return false;
1145 } else {
Jens Axboe274a5842014-08-15 12:44:08 -06001146 struct request_queue *q = hctx->queue;
1147
Jens Axboe07068d52014-05-22 10:40:51 -06001148 spin_lock(&ctx->lock);
1149 if (!blk_mq_attempt_merge(q, ctx, bio)) {
1150 blk_mq_bio_to_request(rq, bio);
1151 goto insert_rq;
1152 }
1153
1154 spin_unlock(&ctx->lock);
1155 __blk_mq_free_request(hctx, ctx, rq);
1156 return true;
1157 }
1158}
1159
1160struct blk_map_ctx {
1161 struct blk_mq_hw_ctx *hctx;
1162 struct blk_mq_ctx *ctx;
1163};
1164
1165static struct request *blk_mq_map_request(struct request_queue *q,
1166 struct bio *bio,
1167 struct blk_map_ctx *data)
Jens Axboe320ae512013-10-24 09:20:05 +01001168{
1169 struct blk_mq_hw_ctx *hctx;
1170 struct blk_mq_ctx *ctx;
Jens Axboe320ae512013-10-24 09:20:05 +01001171 struct request *rq;
Jens Axboe07068d52014-05-22 10:40:51 -06001172 int rw = bio_data_dir(bio);
Ming Leicb96a422014-06-01 00:43:37 +08001173 struct blk_mq_alloc_data alloc_data;
Jens Axboe320ae512013-10-24 09:20:05 +01001174
Dan Williams3ef28e82015-10-21 13:20:12 -04001175 blk_queue_enter_live(q);
Jens Axboe320ae512013-10-24 09:20:05 +01001176 ctx = blk_mq_get_ctx(q);
1177 hctx = q->mq_ops->map_queue(q, ctx->cpu);
1178
Jens Axboe07068d52014-05-22 10:40:51 -06001179 if (rw_is_sync(bio->bi_rw))
Shaohua Li27fbf4e2014-02-19 20:20:21 +08001180 rw |= REQ_SYNC;
Jens Axboe07068d52014-05-22 10:40:51 -06001181
Jens Axboe320ae512013-10-24 09:20:05 +01001182 trace_block_getrq(q, bio, rw);
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +01001183 blk_mq_set_alloc_data(&alloc_data, q, BLK_MQ_REQ_NOWAIT, ctx, hctx);
Ming Leicb96a422014-06-01 00:43:37 +08001184 rq = __blk_mq_alloc_request(&alloc_data, rw);
Christoph Hellwig5dee8572014-05-27 20:59:47 +02001185 if (unlikely(!rq)) {
Christoph Hellwig793597a2014-05-27 20:59:49 +02001186 __blk_mq_run_hw_queue(hctx);
Jens Axboe320ae512013-10-24 09:20:05 +01001187 blk_mq_put_ctx(ctx);
1188 trace_block_sleeprq(q, bio, rw);
Christoph Hellwig793597a2014-05-27 20:59:49 +02001189
1190 ctx = blk_mq_get_ctx(q);
Jens Axboe320ae512013-10-24 09:20:05 +01001191 hctx = q->mq_ops->map_queue(q, ctx->cpu);
Christoph Hellwig6f3b0e82015-11-26 09:13:05 +01001192 blk_mq_set_alloc_data(&alloc_data, q, 0, ctx, hctx);
Ming Leicb96a422014-06-01 00:43:37 +08001193 rq = __blk_mq_alloc_request(&alloc_data, rw);
1194 ctx = alloc_data.ctx;
1195 hctx = alloc_data.hctx;
Jens Axboe320ae512013-10-24 09:20:05 +01001196 }
1197
1198 hctx->queued++;
Jens Axboe07068d52014-05-22 10:40:51 -06001199 data->hctx = hctx;
1200 data->ctx = ctx;
1201 return rq;
1202}
1203
Jens Axboe7b371632015-11-05 10:41:40 -07001204static int blk_mq_direct_issue_request(struct request *rq, blk_qc_t *cookie)
Shaohua Lif984df12015-05-08 10:51:32 -07001205{
1206 int ret;
1207 struct request_queue *q = rq->q;
1208 struct blk_mq_hw_ctx *hctx = q->mq_ops->map_queue(q,
1209 rq->mq_ctx->cpu);
1210 struct blk_mq_queue_data bd = {
1211 .rq = rq,
1212 .list = NULL,
1213 .last = 1
1214 };
Jens Axboe7b371632015-11-05 10:41:40 -07001215 blk_qc_t new_cookie = blk_tag_to_qc_t(rq->tag, hctx->queue_num);
Shaohua Lif984df12015-05-08 10:51:32 -07001216
1217 /*
1218 * For OK queue, we are done. For error, kill it. Any other
1219 * error (busy), just add it to our list as we previously
1220 * would have done
1221 */
1222 ret = q->mq_ops->queue_rq(hctx, &bd);
Jens Axboe7b371632015-11-05 10:41:40 -07001223 if (ret == BLK_MQ_RQ_QUEUE_OK) {
1224 *cookie = new_cookie;
Shaohua Lif984df12015-05-08 10:51:32 -07001225 return 0;
Shaohua Lif984df12015-05-08 10:51:32 -07001226 }
Jens Axboe7b371632015-11-05 10:41:40 -07001227
1228 __blk_mq_requeue_request(rq);
1229
1230 if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
1231 *cookie = BLK_QC_T_NONE;
1232 rq->errors = -EIO;
1233 blk_mq_end_request(rq, rq->errors);
1234 return 0;
1235 }
1236
1237 return -1;
Shaohua Lif984df12015-05-08 10:51:32 -07001238}
1239
Jens Axboe07068d52014-05-22 10:40:51 -06001240/*
1241 * Multiple hardware queue variant. This will not use per-process plugs,
1242 * but will attempt to bypass the hctx queueing if we can go straight to
1243 * hardware for SYNC IO.
1244 */
Jens Axboedece1632015-11-05 10:41:16 -07001245static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
Jens Axboe07068d52014-05-22 10:40:51 -06001246{
1247 const int is_sync = rw_is_sync(bio->bi_rw);
1248 const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
1249 struct blk_map_ctx data;
1250 struct request *rq;
Shaohua Lif984df12015-05-08 10:51:32 -07001251 unsigned int request_count = 0;
1252 struct blk_plug *plug;
Shaohua Li5b3f3412015-05-08 10:51:33 -07001253 struct request *same_queue_rq = NULL;
Jens Axboe7b371632015-11-05 10:41:40 -07001254 blk_qc_t cookie;
Jens Axboe07068d52014-05-22 10:40:51 -06001255
1256 blk_queue_bounce(q, &bio);
1257
1258 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
Christoph Hellwig4246a0b2015-07-20 15:29:37 +02001259 bio_io_error(bio);
Jens Axboedece1632015-11-05 10:41:16 -07001260 return BLK_QC_T_NONE;
Jens Axboe07068d52014-05-22 10:40:51 -06001261 }
1262
Kent Overstreet54efd502015-04-23 22:37:18 -07001263 blk_queue_split(q, &bio, q->bio_split);
1264
Omar Sandoval87c279e2016-06-01 22:18:48 -07001265 if (!is_flush_fua && !blk_queue_nomerges(q) &&
1266 blk_attempt_plug_merge(q, bio, &request_count, &same_queue_rq))
1267 return BLK_QC_T_NONE;
Shaohua Lif984df12015-05-08 10:51:32 -07001268
Jens Axboe07068d52014-05-22 10:40:51 -06001269 rq = blk_mq_map_request(q, bio, &data);
1270 if (unlikely(!rq))
Jens Axboedece1632015-11-05 10:41:16 -07001271 return BLK_QC_T_NONE;
Jens Axboe07068d52014-05-22 10:40:51 -06001272
Jens Axboe7b371632015-11-05 10:41:40 -07001273 cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
Jens Axboe07068d52014-05-22 10:40:51 -06001274
1275 if (unlikely(is_flush_fua)) {
1276 blk_mq_bio_to_request(rq, bio);
1277 blk_insert_flush(rq);
1278 goto run_queue;
1279 }
1280
Shaohua Lif984df12015-05-08 10:51:32 -07001281 plug = current->plug;
Jens Axboee167dfb2014-10-29 11:18:26 -06001282 /*
1283 * If the driver supports defer issued based on 'last', then
1284 * queue it up like normal since we can potentially save some
1285 * CPU this way.
1286 */
Shaohua Lif984df12015-05-08 10:51:32 -07001287 if (((plug && !blk_queue_nomerges(q)) || is_sync) &&
1288 !(data.hctx->flags & BLK_MQ_F_DEFER_ISSUE)) {
1289 struct request *old_rq = NULL;
Jens Axboe07068d52014-05-22 10:40:51 -06001290
1291 blk_mq_bio_to_request(rq, bio);
Jens Axboe07068d52014-05-22 10:40:51 -06001292
1293 /*
Jens Axboeb094f892015-11-20 20:29:45 -07001294 * We do limited pluging. If the bio can be merged, do that.
Shaohua Lif984df12015-05-08 10:51:32 -07001295 * Otherwise the existing request in the plug list will be
1296 * issued. So the plug list will have one request at most
Jens Axboe07068d52014-05-22 10:40:51 -06001297 */
Shaohua Lif984df12015-05-08 10:51:32 -07001298 if (plug) {
Shaohua Li5b3f3412015-05-08 10:51:33 -07001299 /*
1300 * The plug list might get flushed before this. If that
Jens Axboeb094f892015-11-20 20:29:45 -07001301 * happens, same_queue_rq is invalid and plug list is
1302 * empty
1303 */
Shaohua Li5b3f3412015-05-08 10:51:33 -07001304 if (same_queue_rq && !list_empty(&plug->mq_list)) {
1305 old_rq = same_queue_rq;
Shaohua Lif984df12015-05-08 10:51:32 -07001306 list_del_init(&old_rq->queuelist);
Jens Axboe07068d52014-05-22 10:40:51 -06001307 }
Shaohua Lif984df12015-05-08 10:51:32 -07001308 list_add_tail(&rq->queuelist, &plug->mq_list);
1309 } else /* is_sync */
1310 old_rq = rq;
1311 blk_mq_put_ctx(data.ctx);
1312 if (!old_rq)
Jens Axboe7b371632015-11-05 10:41:40 -07001313 goto done;
1314 if (!blk_mq_direct_issue_request(old_rq, &cookie))
1315 goto done;
Shaohua Lif984df12015-05-08 10:51:32 -07001316 blk_mq_insert_request(old_rq, false, true, true);
Jens Axboe7b371632015-11-05 10:41:40 -07001317 goto done;
Jens Axboe07068d52014-05-22 10:40:51 -06001318 }
1319
1320 if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
1321 /*
1322 * For a SYNC request, send it to the hardware immediately. For
1323 * an ASYNC request, just ensure that we run it later on. The
1324 * latter allows for merging opportunities and more efficient
1325 * dispatching.
1326 */
1327run_queue:
1328 blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
1329 }
Jens Axboe07068d52014-05-22 10:40:51 -06001330 blk_mq_put_ctx(data.ctx);
Jens Axboe7b371632015-11-05 10:41:40 -07001331done:
1332 return cookie;
Jens Axboe07068d52014-05-22 10:40:51 -06001333}
1334
1335/*
1336 * Single hardware queue variant. This will attempt to use any per-process
1337 * plug for merging and IO deferral.
1338 */
Jens Axboedece1632015-11-05 10:41:16 -07001339static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
Jens Axboe07068d52014-05-22 10:40:51 -06001340{
1341 const int is_sync = rw_is_sync(bio->bi_rw);
1342 const int is_flush_fua = bio->bi_rw & (REQ_FLUSH | REQ_FUA);
Jeff Moyere6c44382015-05-08 10:51:30 -07001343 struct blk_plug *plug;
1344 unsigned int request_count = 0;
Jens Axboe07068d52014-05-22 10:40:51 -06001345 struct blk_map_ctx data;
1346 struct request *rq;
Jens Axboe7b371632015-11-05 10:41:40 -07001347 blk_qc_t cookie;
Jens Axboe07068d52014-05-22 10:40:51 -06001348
Jens Axboe07068d52014-05-22 10:40:51 -06001349 blk_queue_bounce(q, &bio);
1350
1351 if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
Christoph Hellwig4246a0b2015-07-20 15:29:37 +02001352 bio_io_error(bio);
Jens Axboedece1632015-11-05 10:41:16 -07001353 return BLK_QC_T_NONE;
Jens Axboe07068d52014-05-22 10:40:51 -06001354 }
1355
Kent Overstreet54efd502015-04-23 22:37:18 -07001356 blk_queue_split(q, &bio, q->bio_split);
1357
Omar Sandoval87c279e2016-06-01 22:18:48 -07001358 if (!is_flush_fua && !blk_queue_nomerges(q)) {
1359 if (blk_attempt_plug_merge(q, bio, &request_count, NULL))
1360 return BLK_QC_T_NONE;
1361 } else
1362 request_count = blk_plug_queued_count(q);
Jens Axboe07068d52014-05-22 10:40:51 -06001363
1364 rq = blk_mq_map_request(q, bio, &data);
Jens Axboeff87bce2014-06-03 11:59:49 -06001365 if (unlikely(!rq))
Jens Axboedece1632015-11-05 10:41:16 -07001366 return BLK_QC_T_NONE;
Jens Axboe320ae512013-10-24 09:20:05 +01001367
Jens Axboe7b371632015-11-05 10:41:40 -07001368 cookie = blk_tag_to_qc_t(rq->tag, data.hctx->queue_num);
Jens Axboe320ae512013-10-24 09:20:05 +01001369
1370 if (unlikely(is_flush_fua)) {
1371 blk_mq_bio_to_request(rq, bio);
Jens Axboe320ae512013-10-24 09:20:05 +01001372 blk_insert_flush(rq);
1373 goto run_queue;
1374 }
1375
1376 /*
1377 * A task plug currently exists. Since this is completely lockless,
1378 * utilize that to temporarily store requests until the task is
1379 * either done or scheduled away.
1380 */
Jeff Moyere6c44382015-05-08 10:51:30 -07001381 plug = current->plug;
1382 if (plug) {
1383 blk_mq_bio_to_request(rq, bio);
Ming Lei676d0602015-10-20 23:13:56 +08001384 if (!request_count)
Jeff Moyere6c44382015-05-08 10:51:30 -07001385 trace_block_plug(q);
Jens Axboeb094f892015-11-20 20:29:45 -07001386
1387 blk_mq_put_ctx(data.ctx);
1388
1389 if (request_count >= BLK_MAX_REQUEST_COUNT) {
Jeff Moyere6c44382015-05-08 10:51:30 -07001390 blk_flush_plug_list(plug, false);
1391 trace_block_plug(q);
Jens Axboe320ae512013-10-24 09:20:05 +01001392 }
Jens Axboeb094f892015-11-20 20:29:45 -07001393
Jeff Moyere6c44382015-05-08 10:51:30 -07001394 list_add_tail(&rq->queuelist, &plug->mq_list);
Jens Axboe7b371632015-11-05 10:41:40 -07001395 return cookie;
Jens Axboe320ae512013-10-24 09:20:05 +01001396 }
1397
Jens Axboe07068d52014-05-22 10:40:51 -06001398 if (!blk_mq_merge_queue_io(data.hctx, data.ctx, rq, bio)) {
1399 /*
1400 * For a SYNC request, send it to the hardware immediately. For
1401 * an ASYNC request, just ensure that we run it later on. The
1402 * latter allows for merging opportunities and more efficient
1403 * dispatching.
1404 */
1405run_queue:
1406 blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
Jens Axboe320ae512013-10-24 09:20:05 +01001407 }
1408
Jens Axboe07068d52014-05-22 10:40:51 -06001409 blk_mq_put_ctx(data.ctx);
Jens Axboe7b371632015-11-05 10:41:40 -07001410 return cookie;
Jens Axboe320ae512013-10-24 09:20:05 +01001411}
1412
1413/*
1414 * Default mapping to a software queue, since we use one per CPU.
1415 */
1416struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q, const int cpu)
1417{
1418 return q->queue_hw_ctx[q->mq_map[cpu]];
1419}
1420EXPORT_SYMBOL(blk_mq_map_queue);
1421
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001422static void blk_mq_free_rq_map(struct blk_mq_tag_set *set,
1423 struct blk_mq_tags *tags, unsigned int hctx_idx)
Jens Axboe320ae512013-10-24 09:20:05 +01001424{
1425 struct page *page;
1426
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001427 if (tags->rqs && set->ops->exit_request) {
Christoph Hellwige9b267d2014-04-15 13:59:10 -06001428 int i;
1429
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001430 for (i = 0; i < tags->nr_tags; i++) {
1431 if (!tags->rqs[i])
Christoph Hellwige9b267d2014-04-15 13:59:10 -06001432 continue;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001433 set->ops->exit_request(set->driver_data, tags->rqs[i],
1434 hctx_idx, i);
Jens Axboea5164402014-09-10 09:02:03 -06001435 tags->rqs[i] = NULL;
Christoph Hellwige9b267d2014-04-15 13:59:10 -06001436 }
1437 }
1438
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001439 while (!list_empty(&tags->page_list)) {
1440 page = list_first_entry(&tags->page_list, struct page, lru);
Dave Hansen67534712014-01-08 20:17:46 -07001441 list_del_init(&page->lru);
Catalin Marinasf75782e2015-09-14 18:16:02 +01001442 /*
1443 * Remove kmemleak object previously allocated in
1444 * blk_mq_init_rq_map().
1445 */
1446 kmemleak_free(page_address(page));
Jens Axboe320ae512013-10-24 09:20:05 +01001447 __free_pages(page, page->private);
1448 }
1449
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001450 kfree(tags->rqs);
Jens Axboe320ae512013-10-24 09:20:05 +01001451
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001452 blk_mq_free_tags(tags);
Jens Axboe320ae512013-10-24 09:20:05 +01001453}
1454
1455static size_t order_to_size(unsigned int order)
1456{
Ming Lei4ca08502014-04-19 18:00:18 +08001457 return (size_t)PAGE_SIZE << order;
Jens Axboe320ae512013-10-24 09:20:05 +01001458}
1459
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001460static struct blk_mq_tags *blk_mq_init_rq_map(struct blk_mq_tag_set *set,
1461 unsigned int hctx_idx)
Jens Axboe320ae512013-10-24 09:20:05 +01001462{
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001463 struct blk_mq_tags *tags;
Jens Axboe320ae512013-10-24 09:20:05 +01001464 unsigned int i, j, entries_per_page, max_order = 4;
1465 size_t rq_size, left;
1466
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001467 tags = blk_mq_init_tags(set->queue_depth, set->reserved_tags,
Shaohua Li24391c02015-01-23 14:18:00 -07001468 set->numa_node,
1469 BLK_MQ_FLAG_TO_ALLOC_POLICY(set->flags));
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001470 if (!tags)
1471 return NULL;
Jens Axboe320ae512013-10-24 09:20:05 +01001472
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001473 INIT_LIST_HEAD(&tags->page_list);
1474
Jens Axboea5164402014-09-10 09:02:03 -06001475 tags->rqs = kzalloc_node(set->queue_depth * sizeof(struct request *),
1476 GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY,
1477 set->numa_node);
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001478 if (!tags->rqs) {
1479 blk_mq_free_tags(tags);
1480 return NULL;
1481 }
Jens Axboe320ae512013-10-24 09:20:05 +01001482
1483 /*
1484 * rq_size is the size of the request plus driver payload, rounded
1485 * to the cacheline size
1486 */
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001487 rq_size = round_up(sizeof(struct request) + set->cmd_size,
Jens Axboe320ae512013-10-24 09:20:05 +01001488 cache_line_size());
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001489 left = rq_size * set->queue_depth;
Jens Axboe320ae512013-10-24 09:20:05 +01001490
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001491 for (i = 0; i < set->queue_depth; ) {
Jens Axboe320ae512013-10-24 09:20:05 +01001492 int this_order = max_order;
1493 struct page *page;
1494 int to_do;
1495 void *p;
1496
Bartlomiej Zolnierkiewiczb3a834b2016-05-16 09:54:47 -06001497 while (this_order && left < order_to_size(this_order - 1))
Jens Axboe320ae512013-10-24 09:20:05 +01001498 this_order--;
1499
1500 do {
Jens Axboea5164402014-09-10 09:02:03 -06001501 page = alloc_pages_node(set->numa_node,
Linus Torvaldsac211172015-04-09 14:12:22 -07001502 GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY | __GFP_ZERO,
Jens Axboea5164402014-09-10 09:02:03 -06001503 this_order);
Jens Axboe320ae512013-10-24 09:20:05 +01001504 if (page)
1505 break;
1506 if (!this_order--)
1507 break;
1508 if (order_to_size(this_order) < rq_size)
1509 break;
1510 } while (1);
1511
1512 if (!page)
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001513 goto fail;
Jens Axboe320ae512013-10-24 09:20:05 +01001514
1515 page->private = this_order;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001516 list_add_tail(&page->lru, &tags->page_list);
Jens Axboe320ae512013-10-24 09:20:05 +01001517
1518 p = page_address(page);
Catalin Marinasf75782e2015-09-14 18:16:02 +01001519 /*
1520 * Allow kmemleak to scan these pages as they contain pointers
1521 * to additional allocations like via ops->init_request().
1522 */
1523 kmemleak_alloc(p, order_to_size(this_order), 1, GFP_KERNEL);
Jens Axboe320ae512013-10-24 09:20:05 +01001524 entries_per_page = order_to_size(this_order) / rq_size;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001525 to_do = min(entries_per_page, set->queue_depth - i);
Jens Axboe320ae512013-10-24 09:20:05 +01001526 left -= to_do * rq_size;
1527 for (j = 0; j < to_do; j++) {
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001528 tags->rqs[i] = p;
1529 if (set->ops->init_request) {
1530 if (set->ops->init_request(set->driver_data,
1531 tags->rqs[i], hctx_idx, i,
Jens Axboea5164402014-09-10 09:02:03 -06001532 set->numa_node)) {
1533 tags->rqs[i] = NULL;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001534 goto fail;
Jens Axboea5164402014-09-10 09:02:03 -06001535 }
Christoph Hellwige9b267d2014-04-15 13:59:10 -06001536 }
1537
Jens Axboe320ae512013-10-24 09:20:05 +01001538 p += rq_size;
1539 i++;
1540 }
1541 }
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001542 return tags;
Jens Axboe320ae512013-10-24 09:20:05 +01001543
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001544fail:
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001545 blk_mq_free_rq_map(set, tags, hctx_idx);
1546 return NULL;
Jens Axboe320ae512013-10-24 09:20:05 +01001547}
1548
Jens Axboe1429d7c2014-05-19 09:23:55 -06001549static void blk_mq_free_bitmap(struct blk_mq_ctxmap *bitmap)
1550{
1551 kfree(bitmap->map);
1552}
1553
1554static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap *bitmap, int node)
1555{
1556 unsigned int bpw = 8, total, num_maps, i;
1557
1558 bitmap->bits_per_word = bpw;
1559
1560 num_maps = ALIGN(nr_cpu_ids, bpw) / bpw;
1561 bitmap->map = kzalloc_node(num_maps * sizeof(struct blk_align_bitmap),
1562 GFP_KERNEL, node);
1563 if (!bitmap->map)
1564 return -ENOMEM;
1565
Jens Axboe1429d7c2014-05-19 09:23:55 -06001566 total = nr_cpu_ids;
1567 for (i = 0; i < num_maps; i++) {
1568 bitmap->map[i].depth = min(total, bitmap->bits_per_word);
1569 total -= bitmap->map[i].depth;
1570 }
1571
1572 return 0;
1573}
1574
Jens Axboe484b4062014-05-21 14:01:15 -06001575static int blk_mq_hctx_cpu_offline(struct blk_mq_hw_ctx *hctx, int cpu)
1576{
1577 struct request_queue *q = hctx->queue;
1578 struct blk_mq_ctx *ctx;
1579 LIST_HEAD(tmp);
1580
1581 /*
1582 * Move ctx entries to new CPU, if this one is going away.
1583 */
1584 ctx = __blk_mq_get_ctx(q, cpu);
1585
1586 spin_lock(&ctx->lock);
1587 if (!list_empty(&ctx->rq_list)) {
1588 list_splice_init(&ctx->rq_list, &tmp);
1589 blk_mq_hctx_clear_pending(hctx, ctx);
1590 }
1591 spin_unlock(&ctx->lock);
1592
1593 if (list_empty(&tmp))
1594 return NOTIFY_OK;
1595
1596 ctx = blk_mq_get_ctx(q);
1597 spin_lock(&ctx->lock);
1598
1599 while (!list_empty(&tmp)) {
1600 struct request *rq;
1601
1602 rq = list_first_entry(&tmp, struct request, queuelist);
1603 rq->mq_ctx = ctx;
1604 list_move_tail(&rq->queuelist, &ctx->rq_list);
1605 }
1606
1607 hctx = q->mq_ops->map_queue(q, ctx->cpu);
1608 blk_mq_hctx_mark_pending(hctx, ctx);
1609
1610 spin_unlock(&ctx->lock);
1611
1612 blk_mq_run_hw_queue(hctx, true);
1613 blk_mq_put_ctx(ctx);
1614 return NOTIFY_OK;
1615}
1616
Jens Axboe484b4062014-05-21 14:01:15 -06001617static int blk_mq_hctx_notify(void *data, unsigned long action,
1618 unsigned int cpu)
1619{
1620 struct blk_mq_hw_ctx *hctx = data;
1621
1622 if (action == CPU_DEAD || action == CPU_DEAD_FROZEN)
1623 return blk_mq_hctx_cpu_offline(hctx, cpu);
Ming Lei2a34c082015-04-21 10:00:20 +08001624
1625 /*
1626 * In case of CPU online, tags may be reallocated
1627 * in blk_mq_map_swqueue() after mapping is updated.
1628 */
Jens Axboe484b4062014-05-21 14:01:15 -06001629
1630 return NOTIFY_OK;
1631}
1632
Ming Leic3b4afc2015-06-04 22:25:04 +08001633/* hctx->ctxs will be freed in queue's release handler */
Ming Lei08e98fc2014-09-25 23:23:38 +08001634static void blk_mq_exit_hctx(struct request_queue *q,
1635 struct blk_mq_tag_set *set,
1636 struct blk_mq_hw_ctx *hctx, unsigned int hctx_idx)
1637{
Ming Leif70ced02014-09-25 23:23:47 +08001638 unsigned flush_start_tag = set->queue_depth;
1639
Ming Lei08e98fc2014-09-25 23:23:38 +08001640 blk_mq_tag_idle(hctx);
1641
Ming Leif70ced02014-09-25 23:23:47 +08001642 if (set->ops->exit_request)
1643 set->ops->exit_request(set->driver_data,
1644 hctx->fq->flush_rq, hctx_idx,
1645 flush_start_tag + hctx_idx);
1646
Ming Lei08e98fc2014-09-25 23:23:38 +08001647 if (set->ops->exit_hctx)
1648 set->ops->exit_hctx(hctx, hctx_idx);
1649
1650 blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
Ming Leif70ced02014-09-25 23:23:47 +08001651 blk_free_flush_queue(hctx->fq);
Ming Lei08e98fc2014-09-25 23:23:38 +08001652 blk_mq_free_bitmap(&hctx->ctx_map);
1653}
1654
Ming Lei624dbe42014-05-27 23:35:13 +08001655static void blk_mq_exit_hw_queues(struct request_queue *q,
1656 struct blk_mq_tag_set *set, int nr_queue)
1657{
1658 struct blk_mq_hw_ctx *hctx;
1659 unsigned int i;
1660
1661 queue_for_each_hw_ctx(q, hctx, i) {
1662 if (i == nr_queue)
1663 break;
Ming Lei08e98fc2014-09-25 23:23:38 +08001664 blk_mq_exit_hctx(q, set, hctx, i);
Ming Lei624dbe42014-05-27 23:35:13 +08001665 }
Ming Lei624dbe42014-05-27 23:35:13 +08001666}
1667
1668static void blk_mq_free_hw_queues(struct request_queue *q,
1669 struct blk_mq_tag_set *set)
1670{
1671 struct blk_mq_hw_ctx *hctx;
1672 unsigned int i;
1673
Ming Leie09aae72015-01-29 20:17:27 +08001674 queue_for_each_hw_ctx(q, hctx, i)
Ming Lei624dbe42014-05-27 23:35:13 +08001675 free_cpumask_var(hctx->cpumask);
Ming Lei624dbe42014-05-27 23:35:13 +08001676}
1677
Ming Lei08e98fc2014-09-25 23:23:38 +08001678static int blk_mq_init_hctx(struct request_queue *q,
1679 struct blk_mq_tag_set *set,
1680 struct blk_mq_hw_ctx *hctx, unsigned hctx_idx)
1681{
1682 int node;
Ming Leif70ced02014-09-25 23:23:47 +08001683 unsigned flush_start_tag = set->queue_depth;
Ming Lei08e98fc2014-09-25 23:23:38 +08001684
1685 node = hctx->numa_node;
1686 if (node == NUMA_NO_NODE)
1687 node = hctx->numa_node = set->numa_node;
1688
1689 INIT_DELAYED_WORK(&hctx->run_work, blk_mq_run_work_fn);
1690 INIT_DELAYED_WORK(&hctx->delay_work, blk_mq_delay_work_fn);
1691 spin_lock_init(&hctx->lock);
1692 INIT_LIST_HEAD(&hctx->dispatch);
1693 hctx->queue = q;
1694 hctx->queue_num = hctx_idx;
Jeff Moyer2404e602015-11-03 10:40:06 -05001695 hctx->flags = set->flags & ~BLK_MQ_F_TAG_SHARED;
Ming Lei08e98fc2014-09-25 23:23:38 +08001696
1697 blk_mq_init_cpu_notifier(&hctx->cpu_notifier,
1698 blk_mq_hctx_notify, hctx);
1699 blk_mq_register_cpu_notifier(&hctx->cpu_notifier);
1700
1701 hctx->tags = set->tags[hctx_idx];
1702
1703 /*
1704 * Allocate space for all possible cpus to avoid allocation at
1705 * runtime
1706 */
1707 hctx->ctxs = kmalloc_node(nr_cpu_ids * sizeof(void *),
1708 GFP_KERNEL, node);
1709 if (!hctx->ctxs)
1710 goto unregister_cpu_notifier;
1711
1712 if (blk_mq_alloc_bitmap(&hctx->ctx_map, node))
1713 goto free_ctxs;
1714
1715 hctx->nr_ctx = 0;
1716
1717 if (set->ops->init_hctx &&
1718 set->ops->init_hctx(hctx, set->driver_data, hctx_idx))
1719 goto free_bitmap;
1720
Ming Leif70ced02014-09-25 23:23:47 +08001721 hctx->fq = blk_alloc_flush_queue(q, hctx->numa_node, set->cmd_size);
1722 if (!hctx->fq)
1723 goto exit_hctx;
1724
1725 if (set->ops->init_request &&
1726 set->ops->init_request(set->driver_data,
1727 hctx->fq->flush_rq, hctx_idx,
1728 flush_start_tag + hctx_idx, node))
1729 goto free_fq;
1730
Ming Lei08e98fc2014-09-25 23:23:38 +08001731 return 0;
1732
Ming Leif70ced02014-09-25 23:23:47 +08001733 free_fq:
1734 kfree(hctx->fq);
1735 exit_hctx:
1736 if (set->ops->exit_hctx)
1737 set->ops->exit_hctx(hctx, hctx_idx);
Ming Lei08e98fc2014-09-25 23:23:38 +08001738 free_bitmap:
1739 blk_mq_free_bitmap(&hctx->ctx_map);
1740 free_ctxs:
1741 kfree(hctx->ctxs);
1742 unregister_cpu_notifier:
1743 blk_mq_unregister_cpu_notifier(&hctx->cpu_notifier);
1744
1745 return -1;
1746}
1747
Jens Axboe320ae512013-10-24 09:20:05 +01001748static void blk_mq_init_cpu_queues(struct request_queue *q,
1749 unsigned int nr_hw_queues)
1750{
1751 unsigned int i;
1752
1753 for_each_possible_cpu(i) {
1754 struct blk_mq_ctx *__ctx = per_cpu_ptr(q->queue_ctx, i);
1755 struct blk_mq_hw_ctx *hctx;
1756
1757 memset(__ctx, 0, sizeof(*__ctx));
1758 __ctx->cpu = i;
1759 spin_lock_init(&__ctx->lock);
1760 INIT_LIST_HEAD(&__ctx->rq_list);
1761 __ctx->queue = q;
1762
1763 /* If the cpu isn't online, the cpu is mapped to first hctx */
Jens Axboe320ae512013-10-24 09:20:05 +01001764 if (!cpu_online(i))
1765 continue;
1766
Jens Axboee4043dc2014-04-09 10:18:23 -06001767 hctx = q->mq_ops->map_queue(q, i);
Jens Axboee4043dc2014-04-09 10:18:23 -06001768
Jens Axboe320ae512013-10-24 09:20:05 +01001769 /*
1770 * Set local node, IFF we have more than one hw queue. If
1771 * not, we remain on the home node of the device
1772 */
1773 if (nr_hw_queues > 1 && hctx->numa_node == NUMA_NO_NODE)
Raghavendra K Tbffed452015-12-02 16:59:05 +05301774 hctx->numa_node = local_memory_node(cpu_to_node(i));
Jens Axboe320ae512013-10-24 09:20:05 +01001775 }
1776}
1777
Akinobu Mita57783222015-09-27 02:09:23 +09001778static void blk_mq_map_swqueue(struct request_queue *q,
1779 const struct cpumask *online_mask)
Jens Axboe320ae512013-10-24 09:20:05 +01001780{
1781 unsigned int i;
1782 struct blk_mq_hw_ctx *hctx;
1783 struct blk_mq_ctx *ctx;
Ming Lei2a34c082015-04-21 10:00:20 +08001784 struct blk_mq_tag_set *set = q->tag_set;
Jens Axboe320ae512013-10-24 09:20:05 +01001785
Akinobu Mita60de0742015-09-27 02:09:25 +09001786 /*
1787 * Avoid others reading imcomplete hctx->cpumask through sysfs
1788 */
1789 mutex_lock(&q->sysfs_lock);
1790
Jens Axboe320ae512013-10-24 09:20:05 +01001791 queue_for_each_hw_ctx(q, hctx, i) {
Jens Axboee4043dc2014-04-09 10:18:23 -06001792 cpumask_clear(hctx->cpumask);
Jens Axboe320ae512013-10-24 09:20:05 +01001793 hctx->nr_ctx = 0;
1794 }
1795
1796 /*
1797 * Map software to hardware queues
1798 */
Thomas Gleixner897bb0c2016-03-19 11:30:33 +01001799 for_each_possible_cpu(i) {
Jens Axboe320ae512013-10-24 09:20:05 +01001800 /* If the cpu isn't online, the cpu is mapped to first hctx */
Akinobu Mita57783222015-09-27 02:09:23 +09001801 if (!cpumask_test_cpu(i, online_mask))
Jens Axboee4043dc2014-04-09 10:18:23 -06001802 continue;
1803
Thomas Gleixner897bb0c2016-03-19 11:30:33 +01001804 ctx = per_cpu_ptr(q->queue_ctx, i);
Jens Axboe320ae512013-10-24 09:20:05 +01001805 hctx = q->mq_ops->map_queue(q, i);
Keith Busch868f2f02015-12-17 17:08:14 -07001806
Jens Axboee4043dc2014-04-09 10:18:23 -06001807 cpumask_set_cpu(i, hctx->cpumask);
Jens Axboe320ae512013-10-24 09:20:05 +01001808 ctx->index_hw = hctx->nr_ctx;
1809 hctx->ctxs[hctx->nr_ctx++] = ctx;
1810 }
Jens Axboe506e9312014-05-07 10:26:44 -06001811
Akinobu Mita60de0742015-09-27 02:09:25 +09001812 mutex_unlock(&q->sysfs_lock);
1813
Jens Axboe506e9312014-05-07 10:26:44 -06001814 queue_for_each_hw_ctx(q, hctx, i) {
Chong Yuan889fa312015-04-15 11:39:29 -06001815 struct blk_mq_ctxmap *map = &hctx->ctx_map;
1816
Jens Axboe484b4062014-05-21 14:01:15 -06001817 /*
Jens Axboea68aafa2014-08-15 13:19:15 -06001818 * If no software queues are mapped to this hardware queue,
1819 * disable it and free the request entries.
Jens Axboe484b4062014-05-21 14:01:15 -06001820 */
1821 if (!hctx->nr_ctx) {
Jens Axboe484b4062014-05-21 14:01:15 -06001822 if (set->tags[i]) {
1823 blk_mq_free_rq_map(set, set->tags[i], i);
1824 set->tags[i] = NULL;
Jens Axboe484b4062014-05-21 14:01:15 -06001825 }
Ming Lei2a34c082015-04-21 10:00:20 +08001826 hctx->tags = NULL;
Jens Axboe484b4062014-05-21 14:01:15 -06001827 continue;
1828 }
1829
Ming Lei2a34c082015-04-21 10:00:20 +08001830 /* unmapped hw queue can be remapped after CPU topo changed */
1831 if (!set->tags[i])
1832 set->tags[i] = blk_mq_init_rq_map(set, i);
1833 hctx->tags = set->tags[i];
1834 WARN_ON(!hctx->tags);
1835
Raghavendra K Te0e827b2015-12-02 16:57:06 +05301836 cpumask_copy(hctx->tags->cpumask, hctx->cpumask);
Jens Axboe484b4062014-05-21 14:01:15 -06001837 /*
Chong Yuan889fa312015-04-15 11:39:29 -06001838 * Set the map size to the number of mapped software queues.
1839 * This is more accurate and more efficient than looping
1840 * over all possibly mapped software queues.
1841 */
Jens Axboe569fd0c2015-04-17 08:28:50 -06001842 map->size = DIV_ROUND_UP(hctx->nr_ctx, map->bits_per_word);
Chong Yuan889fa312015-04-15 11:39:29 -06001843
1844 /*
Jens Axboe484b4062014-05-21 14:01:15 -06001845 * Initialize batch roundrobin counts
1846 */
Jens Axboe506e9312014-05-07 10:26:44 -06001847 hctx->next_cpu = cpumask_first(hctx->cpumask);
1848 hctx->next_cpu_batch = BLK_MQ_CPU_WORK_BATCH;
1849 }
Jens Axboe320ae512013-10-24 09:20:05 +01001850}
1851
Jeff Moyer2404e602015-11-03 10:40:06 -05001852static void queue_set_hctx_shared(struct request_queue *q, bool shared)
Jens Axboe0d2602c2014-05-13 15:10:52 -06001853{
1854 struct blk_mq_hw_ctx *hctx;
Jens Axboe0d2602c2014-05-13 15:10:52 -06001855 int i;
1856
Jeff Moyer2404e602015-11-03 10:40:06 -05001857 queue_for_each_hw_ctx(q, hctx, i) {
1858 if (shared)
1859 hctx->flags |= BLK_MQ_F_TAG_SHARED;
1860 else
1861 hctx->flags &= ~BLK_MQ_F_TAG_SHARED;
1862 }
1863}
1864
1865static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set *set, bool shared)
1866{
1867 struct request_queue *q;
Jens Axboe0d2602c2014-05-13 15:10:52 -06001868
1869 list_for_each_entry(q, &set->tag_list, tag_set_list) {
1870 blk_mq_freeze_queue(q);
Jeff Moyer2404e602015-11-03 10:40:06 -05001871 queue_set_hctx_shared(q, shared);
Jens Axboe0d2602c2014-05-13 15:10:52 -06001872 blk_mq_unfreeze_queue(q);
1873 }
1874}
1875
1876static void blk_mq_del_queue_tag_set(struct request_queue *q)
1877{
1878 struct blk_mq_tag_set *set = q->tag_set;
1879
Jens Axboe0d2602c2014-05-13 15:10:52 -06001880 mutex_lock(&set->tag_list_lock);
1881 list_del_init(&q->tag_set_list);
Jeff Moyer2404e602015-11-03 10:40:06 -05001882 if (list_is_singular(&set->tag_list)) {
1883 /* just transitioned to unshared */
1884 set->flags &= ~BLK_MQ_F_TAG_SHARED;
1885 /* update existing queue */
1886 blk_mq_update_tag_set_depth(set, false);
1887 }
Jens Axboe0d2602c2014-05-13 15:10:52 -06001888 mutex_unlock(&set->tag_list_lock);
Jens Axboe0d2602c2014-05-13 15:10:52 -06001889}
1890
1891static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set *set,
1892 struct request_queue *q)
1893{
1894 q->tag_set = set;
1895
1896 mutex_lock(&set->tag_list_lock);
Jeff Moyer2404e602015-11-03 10:40:06 -05001897
1898 /* Check to see if we're transitioning to shared (from 1 to 2 queues). */
1899 if (!list_empty(&set->tag_list) && !(set->flags & BLK_MQ_F_TAG_SHARED)) {
1900 set->flags |= BLK_MQ_F_TAG_SHARED;
1901 /* update existing queue */
1902 blk_mq_update_tag_set_depth(set, true);
1903 }
1904 if (set->flags & BLK_MQ_F_TAG_SHARED)
1905 queue_set_hctx_shared(q, true);
Jens Axboe0d2602c2014-05-13 15:10:52 -06001906 list_add_tail(&q->tag_set_list, &set->tag_list);
Jeff Moyer2404e602015-11-03 10:40:06 -05001907
Jens Axboe0d2602c2014-05-13 15:10:52 -06001908 mutex_unlock(&set->tag_list_lock);
1909}
1910
Ming Leie09aae72015-01-29 20:17:27 +08001911/*
1912 * It is the actual release handler for mq, but we do it from
1913 * request queue's release handler for avoiding use-after-free
1914 * and headache because q->mq_kobj shouldn't have been introduced,
1915 * but we can't group ctx/kctx kobj without it.
1916 */
1917void blk_mq_release(struct request_queue *q)
1918{
1919 struct blk_mq_hw_ctx *hctx;
1920 unsigned int i;
1921
1922 /* hctx kobj stays in hctx */
Ming Leic3b4afc2015-06-04 22:25:04 +08001923 queue_for_each_hw_ctx(q, hctx, i) {
1924 if (!hctx)
1925 continue;
1926 kfree(hctx->ctxs);
Ming Leie09aae72015-01-29 20:17:27 +08001927 kfree(hctx);
Ming Leic3b4afc2015-06-04 22:25:04 +08001928 }
Ming Leie09aae72015-01-29 20:17:27 +08001929
Akinobu Mitaa723bab2015-09-27 02:09:21 +09001930 kfree(q->mq_map);
1931 q->mq_map = NULL;
1932
Ming Leie09aae72015-01-29 20:17:27 +08001933 kfree(q->queue_hw_ctx);
1934
1935 /* ctx kobj stays in queue_ctx */
1936 free_percpu(q->queue_ctx);
1937}
1938
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001939struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *set)
Jens Axboe320ae512013-10-24 09:20:05 +01001940{
Mike Snitzerb62c21b2015-03-12 23:56:02 -04001941 struct request_queue *uninit_q, *q;
1942
1943 uninit_q = blk_alloc_queue_node(GFP_KERNEL, set->numa_node);
1944 if (!uninit_q)
1945 return ERR_PTR(-ENOMEM);
1946
1947 q = blk_mq_init_allocated_queue(set, uninit_q);
1948 if (IS_ERR(q))
1949 blk_cleanup_queue(uninit_q);
1950
1951 return q;
1952}
1953EXPORT_SYMBOL(blk_mq_init_queue);
1954
Keith Busch868f2f02015-12-17 17:08:14 -07001955static void blk_mq_realloc_hw_ctxs(struct blk_mq_tag_set *set,
1956 struct request_queue *q)
Mike Snitzerb62c21b2015-03-12 23:56:02 -04001957{
Keith Busch868f2f02015-12-17 17:08:14 -07001958 int i, j;
1959 struct blk_mq_hw_ctx **hctxs = q->queue_hw_ctx;
Jens Axboe320ae512013-10-24 09:20:05 +01001960
Keith Busch868f2f02015-12-17 17:08:14 -07001961 blk_mq_sysfs_unregister(q);
Christoph Hellwig24d2f902014-04-15 14:14:00 -06001962 for (i = 0; i < set->nr_hw_queues; i++) {
Keith Busch868f2f02015-12-17 17:08:14 -07001963 int node;
Jens Axboef14bbe72014-05-27 12:06:53 -06001964
Keith Busch868f2f02015-12-17 17:08:14 -07001965 if (hctxs[i])
1966 continue;
1967
1968 node = blk_mq_hw_queue_to_node(q->mq_map, i);
Christoph Hellwigcdef54d2014-05-28 18:11:06 +02001969 hctxs[i] = kzalloc_node(sizeof(struct blk_mq_hw_ctx),
1970 GFP_KERNEL, node);
Jens Axboe320ae512013-10-24 09:20:05 +01001971 if (!hctxs[i])
Keith Busch868f2f02015-12-17 17:08:14 -07001972 break;
Jens Axboe320ae512013-10-24 09:20:05 +01001973
Jens Axboea86073e2014-10-13 15:41:54 -06001974 if (!zalloc_cpumask_var_node(&hctxs[i]->cpumask, GFP_KERNEL,
Keith Busch868f2f02015-12-17 17:08:14 -07001975 node)) {
1976 kfree(hctxs[i]);
1977 hctxs[i] = NULL;
1978 break;
1979 }
Jens Axboee4043dc2014-04-09 10:18:23 -06001980
Jens Axboe0d2602c2014-05-13 15:10:52 -06001981 atomic_set(&hctxs[i]->nr_active, 0);
Jens Axboef14bbe72014-05-27 12:06:53 -06001982 hctxs[i]->numa_node = node;
Jens Axboe320ae512013-10-24 09:20:05 +01001983 hctxs[i]->queue_num = i;
Keith Busch868f2f02015-12-17 17:08:14 -07001984
1985 if (blk_mq_init_hctx(q, set, hctxs[i], i)) {
1986 free_cpumask_var(hctxs[i]->cpumask);
1987 kfree(hctxs[i]);
1988 hctxs[i] = NULL;
1989 break;
1990 }
1991 blk_mq_hctx_kobj_init(hctxs[i]);
Jens Axboe320ae512013-10-24 09:20:05 +01001992 }
Keith Busch868f2f02015-12-17 17:08:14 -07001993 for (j = i; j < q->nr_hw_queues; j++) {
1994 struct blk_mq_hw_ctx *hctx = hctxs[j];
1995
1996 if (hctx) {
1997 if (hctx->tags) {
1998 blk_mq_free_rq_map(set, hctx->tags, j);
1999 set->tags[j] = NULL;
2000 }
2001 blk_mq_exit_hctx(q, set, hctx, j);
2002 free_cpumask_var(hctx->cpumask);
2003 kobject_put(&hctx->kobj);
2004 kfree(hctx->ctxs);
2005 kfree(hctx);
2006 hctxs[j] = NULL;
2007
2008 }
2009 }
2010 q->nr_hw_queues = i;
2011 blk_mq_sysfs_register(q);
2012}
2013
2014struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
2015 struct request_queue *q)
2016{
Ming Lei66841672016-02-12 15:27:00 +08002017 /* mark the queue as mq asap */
2018 q->mq_ops = set->ops;
2019
Keith Busch868f2f02015-12-17 17:08:14 -07002020 q->queue_ctx = alloc_percpu(struct blk_mq_ctx);
2021 if (!q->queue_ctx)
Ming Linc7de5722016-05-25 23:23:27 -07002022 goto err_exit;
Keith Busch868f2f02015-12-17 17:08:14 -07002023
2024 q->queue_hw_ctx = kzalloc_node(nr_cpu_ids * sizeof(*(q->queue_hw_ctx)),
2025 GFP_KERNEL, set->numa_node);
2026 if (!q->queue_hw_ctx)
2027 goto err_percpu;
2028
2029 q->mq_map = blk_mq_make_queue_map(set);
2030 if (!q->mq_map)
2031 goto err_map;
2032
2033 blk_mq_realloc_hw_ctxs(set, q);
2034 if (!q->nr_hw_queues)
2035 goto err_hctxs;
Jens Axboe320ae512013-10-24 09:20:05 +01002036
Christoph Hellwig287922e2015-10-30 20:57:30 +08002037 INIT_WORK(&q->timeout_work, blk_mq_timeout_work);
Ming Leie56f6982015-07-16 19:53:22 +08002038 blk_queue_rq_timeout(q, set->timeout ? set->timeout : 30 * HZ);
Jens Axboe320ae512013-10-24 09:20:05 +01002039
2040 q->nr_queues = nr_cpu_ids;
Jens Axboe320ae512013-10-24 09:20:05 +01002041
Jens Axboe94eddfb2013-11-19 09:25:07 -07002042 q->queue_flags |= QUEUE_FLAG_MQ_DEFAULT;
Jens Axboe320ae512013-10-24 09:20:05 +01002043
Jens Axboe05f1dd52014-05-29 09:53:32 -06002044 if (!(set->flags & BLK_MQ_F_SG_MERGE))
2045 q->queue_flags |= 1 << QUEUE_FLAG_NO_SG_MERGE;
2046
Christoph Hellwig1be036e2014-02-07 10:22:39 -08002047 q->sg_reserved_size = INT_MAX;
2048
Christoph Hellwig6fca6a62014-05-28 08:08:02 -06002049 INIT_WORK(&q->requeue_work, blk_mq_requeue_work);
2050 INIT_LIST_HEAD(&q->requeue_list);
2051 spin_lock_init(&q->requeue_lock);
2052
Jens Axboe07068d52014-05-22 10:40:51 -06002053 if (q->nr_hw_queues > 1)
2054 blk_queue_make_request(q, blk_mq_make_request);
2055 else
2056 blk_queue_make_request(q, blk_sq_make_request);
2057
Jens Axboeeba71762014-05-20 15:17:27 -06002058 /*
2059 * Do this after blk_queue_make_request() overrides it...
2060 */
2061 q->nr_requests = set->queue_depth;
2062
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002063 if (set->ops->complete)
2064 blk_queue_softirq_done(q, set->ops->complete);
Christoph Hellwig30a91cb2014-02-10 03:24:38 -08002065
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002066 blk_mq_init_cpu_queues(q, set->nr_hw_queues);
Jens Axboe320ae512013-10-24 09:20:05 +01002067
Akinobu Mita57783222015-09-27 02:09:23 +09002068 get_online_cpus();
Jens Axboe320ae512013-10-24 09:20:05 +01002069 mutex_lock(&all_q_mutex);
Akinobu Mita4593fdb2015-09-27 02:09:20 +09002070
Jens Axboe320ae512013-10-24 09:20:05 +01002071 list_add_tail(&q->all_q_node, &all_q_list);
Jens Axboe0d2602c2014-05-13 15:10:52 -06002072 blk_mq_add_queue_tag_set(set, q);
Akinobu Mita57783222015-09-27 02:09:23 +09002073 blk_mq_map_swqueue(q, cpu_online_mask);
Jens Axboe484b4062014-05-21 14:01:15 -06002074
Akinobu Mita4593fdb2015-09-27 02:09:20 +09002075 mutex_unlock(&all_q_mutex);
Akinobu Mita57783222015-09-27 02:09:23 +09002076 put_online_cpus();
Akinobu Mita4593fdb2015-09-27 02:09:20 +09002077
Jens Axboe320ae512013-10-24 09:20:05 +01002078 return q;
Christoph Hellwig18741982014-02-10 09:29:00 -07002079
Jens Axboe320ae512013-10-24 09:20:05 +01002080err_hctxs:
Keith Busch868f2f02015-12-17 17:08:14 -07002081 kfree(q->mq_map);
Jens Axboef14bbe72014-05-27 12:06:53 -06002082err_map:
Keith Busch868f2f02015-12-17 17:08:14 -07002083 kfree(q->queue_hw_ctx);
Jens Axboe320ae512013-10-24 09:20:05 +01002084err_percpu:
Keith Busch868f2f02015-12-17 17:08:14 -07002085 free_percpu(q->queue_ctx);
Ming Linc7de5722016-05-25 23:23:27 -07002086err_exit:
2087 q->mq_ops = NULL;
Jens Axboe320ae512013-10-24 09:20:05 +01002088 return ERR_PTR(-ENOMEM);
2089}
Mike Snitzerb62c21b2015-03-12 23:56:02 -04002090EXPORT_SYMBOL(blk_mq_init_allocated_queue);
Jens Axboe320ae512013-10-24 09:20:05 +01002091
2092void blk_mq_free_queue(struct request_queue *q)
2093{
Ming Lei624dbe42014-05-27 23:35:13 +08002094 struct blk_mq_tag_set *set = q->tag_set;
Jens Axboe320ae512013-10-24 09:20:05 +01002095
Akinobu Mita0e626362015-09-27 02:09:22 +09002096 mutex_lock(&all_q_mutex);
2097 list_del_init(&q->all_q_node);
2098 mutex_unlock(&all_q_mutex);
2099
Jens Axboe0d2602c2014-05-13 15:10:52 -06002100 blk_mq_del_queue_tag_set(q);
2101
Ming Lei624dbe42014-05-27 23:35:13 +08002102 blk_mq_exit_hw_queues(q, set, set->nr_hw_queues);
2103 blk_mq_free_hw_queues(q, set);
Jens Axboe320ae512013-10-24 09:20:05 +01002104}
Jens Axboe320ae512013-10-24 09:20:05 +01002105
2106/* Basically redo blk_mq_init_queue with queue frozen */
Akinobu Mita57783222015-09-27 02:09:23 +09002107static void blk_mq_queue_reinit(struct request_queue *q,
2108 const struct cpumask *online_mask)
Jens Axboe320ae512013-10-24 09:20:05 +01002109{
Christoph Hellwig4ecd4fe2015-05-07 09:38:13 +02002110 WARN_ON_ONCE(!atomic_read(&q->mq_freeze_depth));
Jens Axboe320ae512013-10-24 09:20:05 +01002111
Jens Axboe67aec142014-05-30 08:25:36 -06002112 blk_mq_sysfs_unregister(q);
2113
Akinobu Mita57783222015-09-27 02:09:23 +09002114 blk_mq_update_queue_map(q->mq_map, q->nr_hw_queues, online_mask);
Jens Axboe320ae512013-10-24 09:20:05 +01002115
2116 /*
2117 * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
2118 * we should change hctx numa_node according to new topology (this
2119 * involves free and re-allocate memory, worthy doing?)
2120 */
2121
Akinobu Mita57783222015-09-27 02:09:23 +09002122 blk_mq_map_swqueue(q, online_mask);
Jens Axboe320ae512013-10-24 09:20:05 +01002123
Jens Axboe67aec142014-05-30 08:25:36 -06002124 blk_mq_sysfs_register(q);
Jens Axboe320ae512013-10-24 09:20:05 +01002125}
2126
Paul Gortmakerf618ef72013-11-14 08:26:02 -07002127static int blk_mq_queue_reinit_notify(struct notifier_block *nb,
2128 unsigned long action, void *hcpu)
Jens Axboe320ae512013-10-24 09:20:05 +01002129{
2130 struct request_queue *q;
Akinobu Mita57783222015-09-27 02:09:23 +09002131 int cpu = (unsigned long)hcpu;
2132 /*
2133 * New online cpumask which is going to be set in this hotplug event.
2134 * Declare this cpumasks as global as cpu-hotplug operation is invoked
2135 * one-by-one and dynamically allocating this could result in a failure.
2136 */
2137 static struct cpumask online_new;
Jens Axboe320ae512013-10-24 09:20:05 +01002138
2139 /*
Akinobu Mita57783222015-09-27 02:09:23 +09002140 * Before hotadded cpu starts handling requests, new mappings must
2141 * be established. Otherwise, these requests in hw queue might
2142 * never be dispatched.
2143 *
2144 * For example, there is a single hw queue (hctx) and two CPU queues
2145 * (ctx0 for CPU0, and ctx1 for CPU1).
2146 *
2147 * Now CPU1 is just onlined and a request is inserted into
2148 * ctx1->rq_list and set bit0 in pending bitmap as ctx1->index_hw is
2149 * still zero.
2150 *
2151 * And then while running hw queue, flush_busy_ctxs() finds bit0 is
2152 * set in pending bitmap and tries to retrieve requests in
2153 * hctx->ctxs[0]->rq_list. But htx->ctxs[0] is a pointer to ctx0,
2154 * so the request in ctx1->rq_list is ignored.
Jens Axboe320ae512013-10-24 09:20:05 +01002155 */
Akinobu Mita57783222015-09-27 02:09:23 +09002156 switch (action & ~CPU_TASKS_FROZEN) {
2157 case CPU_DEAD:
2158 case CPU_UP_CANCELED:
2159 cpumask_copy(&online_new, cpu_online_mask);
2160 break;
2161 case CPU_UP_PREPARE:
2162 cpumask_copy(&online_new, cpu_online_mask);
2163 cpumask_set_cpu(cpu, &online_new);
2164 break;
2165 default:
Jens Axboe320ae512013-10-24 09:20:05 +01002166 return NOTIFY_OK;
Akinobu Mita57783222015-09-27 02:09:23 +09002167 }
Jens Axboe320ae512013-10-24 09:20:05 +01002168
2169 mutex_lock(&all_q_mutex);
Tejun Heof3af0202014-11-04 13:52:27 -05002170
2171 /*
2172 * We need to freeze and reinit all existing queues. Freezing
2173 * involves synchronous wait for an RCU grace period and doing it
2174 * one by one may take a long time. Start freezing all queues in
2175 * one swoop and then wait for the completions so that freezing can
2176 * take place in parallel.
2177 */
2178 list_for_each_entry(q, &all_q_list, all_q_node)
2179 blk_mq_freeze_queue_start(q);
Ming Leif054b562015-04-21 10:00:19 +08002180 list_for_each_entry(q, &all_q_list, all_q_node) {
Tejun Heof3af0202014-11-04 13:52:27 -05002181 blk_mq_freeze_queue_wait(q);
2182
Ming Leif054b562015-04-21 10:00:19 +08002183 /*
2184 * timeout handler can't touch hw queue during the
2185 * reinitialization
2186 */
2187 del_timer_sync(&q->timeout);
2188 }
2189
Jens Axboe320ae512013-10-24 09:20:05 +01002190 list_for_each_entry(q, &all_q_list, all_q_node)
Akinobu Mita57783222015-09-27 02:09:23 +09002191 blk_mq_queue_reinit(q, &online_new);
Tejun Heof3af0202014-11-04 13:52:27 -05002192
2193 list_for_each_entry(q, &all_q_list, all_q_node)
2194 blk_mq_unfreeze_queue(q);
2195
Jens Axboe320ae512013-10-24 09:20:05 +01002196 mutex_unlock(&all_q_mutex);
2197 return NOTIFY_OK;
2198}
2199
Jens Axboea5164402014-09-10 09:02:03 -06002200static int __blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
2201{
2202 int i;
2203
2204 for (i = 0; i < set->nr_hw_queues; i++) {
2205 set->tags[i] = blk_mq_init_rq_map(set, i);
2206 if (!set->tags[i])
2207 goto out_unwind;
2208 }
2209
2210 return 0;
2211
2212out_unwind:
2213 while (--i >= 0)
2214 blk_mq_free_rq_map(set, set->tags[i], i);
2215
Jens Axboea5164402014-09-10 09:02:03 -06002216 return -ENOMEM;
2217}
2218
2219/*
2220 * Allocate the request maps associated with this tag_set. Note that this
2221 * may reduce the depth asked for, if memory is tight. set->queue_depth
2222 * will be updated to reflect the allocated depth.
2223 */
2224static int blk_mq_alloc_rq_maps(struct blk_mq_tag_set *set)
2225{
2226 unsigned int depth;
2227 int err;
2228
2229 depth = set->queue_depth;
2230 do {
2231 err = __blk_mq_alloc_rq_maps(set);
2232 if (!err)
2233 break;
2234
2235 set->queue_depth >>= 1;
2236 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN) {
2237 err = -ENOMEM;
2238 break;
2239 }
2240 } while (set->queue_depth);
2241
2242 if (!set->queue_depth || err) {
2243 pr_err("blk-mq: failed to allocate request map\n");
2244 return -ENOMEM;
2245 }
2246
2247 if (depth != set->queue_depth)
2248 pr_info("blk-mq: reduced tag depth (%u -> %u)\n",
2249 depth, set->queue_depth);
2250
2251 return 0;
2252}
2253
Keith Buschf26cdc82015-06-01 09:29:53 -06002254struct cpumask *blk_mq_tags_cpumask(struct blk_mq_tags *tags)
2255{
2256 return tags->cpumask;
2257}
2258EXPORT_SYMBOL_GPL(blk_mq_tags_cpumask);
2259
Jens Axboea4391c62014-06-05 15:21:56 -06002260/*
2261 * Alloc a tag set to be associated with one or more request queues.
2262 * May fail with EINVAL for various error conditions. May adjust the
2263 * requested depth down, if if it too large. In that case, the set
2264 * value will be stored in set->queue_depth.
2265 */
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002266int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set)
2267{
Bart Van Assche205fb5f2014-10-30 14:45:11 +01002268 BUILD_BUG_ON(BLK_MQ_MAX_DEPTH > 1 << BLK_MQ_UNIQUE_TAG_BITS);
2269
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002270 if (!set->nr_hw_queues)
2271 return -EINVAL;
Jens Axboea4391c62014-06-05 15:21:56 -06002272 if (!set->queue_depth)
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002273 return -EINVAL;
2274 if (set->queue_depth < set->reserved_tags + BLK_MQ_TAG_MIN)
2275 return -EINVAL;
2276
Xiaoguang Wangf9018ac2015-03-30 13:19:14 +08002277 if (!set->ops->queue_rq || !set->ops->map_queue)
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002278 return -EINVAL;
2279
Jens Axboea4391c62014-06-05 15:21:56 -06002280 if (set->queue_depth > BLK_MQ_MAX_DEPTH) {
2281 pr_info("blk-mq: reduced tag depth to %u\n",
2282 BLK_MQ_MAX_DEPTH);
2283 set->queue_depth = BLK_MQ_MAX_DEPTH;
2284 }
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002285
Shaohua Li6637fad2014-11-30 16:00:58 -08002286 /*
2287 * If a crashdump is active, then we are potentially in a very
2288 * memory constrained environment. Limit us to 1 queue and
2289 * 64 tags to prevent using too much memory.
2290 */
2291 if (is_kdump_kernel()) {
2292 set->nr_hw_queues = 1;
2293 set->queue_depth = min(64U, set->queue_depth);
2294 }
Keith Busch868f2f02015-12-17 17:08:14 -07002295 /*
2296 * There is no use for more h/w queues than cpus.
2297 */
2298 if (set->nr_hw_queues > nr_cpu_ids)
2299 set->nr_hw_queues = nr_cpu_ids;
Shaohua Li6637fad2014-11-30 16:00:58 -08002300
Keith Busch868f2f02015-12-17 17:08:14 -07002301 set->tags = kzalloc_node(nr_cpu_ids * sizeof(struct blk_mq_tags *),
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002302 GFP_KERNEL, set->numa_node);
2303 if (!set->tags)
Jens Axboea5164402014-09-10 09:02:03 -06002304 return -ENOMEM;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002305
Jens Axboea5164402014-09-10 09:02:03 -06002306 if (blk_mq_alloc_rq_maps(set))
2307 goto enomem;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002308
Jens Axboe0d2602c2014-05-13 15:10:52 -06002309 mutex_init(&set->tag_list_lock);
2310 INIT_LIST_HEAD(&set->tag_list);
2311
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002312 return 0;
Jens Axboea5164402014-09-10 09:02:03 -06002313enomem:
Robert Elliott5676e7b2014-09-02 11:38:44 -05002314 kfree(set->tags);
2315 set->tags = NULL;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002316 return -ENOMEM;
2317}
2318EXPORT_SYMBOL(blk_mq_alloc_tag_set);
2319
2320void blk_mq_free_tag_set(struct blk_mq_tag_set *set)
2321{
2322 int i;
2323
Keith Busch868f2f02015-12-17 17:08:14 -07002324 for (i = 0; i < nr_cpu_ids; i++) {
Junichi Nomuraf42d79a2015-10-14 05:02:15 +00002325 if (set->tags[i])
Jens Axboe484b4062014-05-21 14:01:15 -06002326 blk_mq_free_rq_map(set, set->tags[i], i);
2327 }
2328
Ming Lei981bd182014-04-24 00:07:34 +08002329 kfree(set->tags);
Robert Elliott5676e7b2014-09-02 11:38:44 -05002330 set->tags = NULL;
Christoph Hellwig24d2f902014-04-15 14:14:00 -06002331}
2332EXPORT_SYMBOL(blk_mq_free_tag_set);
2333
Jens Axboee3a2b3f2014-05-20 11:49:02 -06002334int blk_mq_update_nr_requests(struct request_queue *q, unsigned int nr)
2335{
2336 struct blk_mq_tag_set *set = q->tag_set;
2337 struct blk_mq_hw_ctx *hctx;
2338 int i, ret;
2339
2340 if (!set || nr > set->queue_depth)
2341 return -EINVAL;
2342
2343 ret = 0;
2344 queue_for_each_hw_ctx(q, hctx, i) {
Keith Busche9137d42016-02-18 14:56:35 -07002345 if (!hctx->tags)
2346 continue;
Jens Axboee3a2b3f2014-05-20 11:49:02 -06002347 ret = blk_mq_tag_update_depth(hctx->tags, nr);
2348 if (ret)
2349 break;
2350 }
2351
2352 if (!ret)
2353 q->nr_requests = nr;
2354
2355 return ret;
2356}
2357
Keith Busch868f2f02015-12-17 17:08:14 -07002358void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues)
2359{
2360 struct request_queue *q;
2361
2362 if (nr_hw_queues > nr_cpu_ids)
2363 nr_hw_queues = nr_cpu_ids;
2364 if (nr_hw_queues < 1 || nr_hw_queues == set->nr_hw_queues)
2365 return;
2366
2367 list_for_each_entry(q, &set->tag_list, tag_set_list)
2368 blk_mq_freeze_queue(q);
2369
2370 set->nr_hw_queues = nr_hw_queues;
2371 list_for_each_entry(q, &set->tag_list, tag_set_list) {
2372 blk_mq_realloc_hw_ctxs(set, q);
2373
2374 if (q->nr_hw_queues > 1)
2375 blk_queue_make_request(q, blk_mq_make_request);
2376 else
2377 blk_queue_make_request(q, blk_sq_make_request);
2378
2379 blk_mq_queue_reinit(q, cpu_online_mask);
2380 }
2381
2382 list_for_each_entry(q, &set->tag_list, tag_set_list)
2383 blk_mq_unfreeze_queue(q);
2384}
2385EXPORT_SYMBOL_GPL(blk_mq_update_nr_hw_queues);
2386
Jens Axboe676141e2014-03-20 13:29:18 -06002387void blk_mq_disable_hotplug(void)
2388{
2389 mutex_lock(&all_q_mutex);
2390}
2391
2392void blk_mq_enable_hotplug(void)
2393{
2394 mutex_unlock(&all_q_mutex);
2395}
2396
Jens Axboe320ae512013-10-24 09:20:05 +01002397static int __init blk_mq_init(void)
2398{
Jens Axboe320ae512013-10-24 09:20:05 +01002399 blk_mq_cpu_init();
2400
Tejun Heoadd703f2014-07-01 10:34:38 -06002401 hotcpu_notifier(blk_mq_queue_reinit_notify, 0);
Jens Axboe320ae512013-10-24 09:20:05 +01002402
2403 return 0;
2404}
2405subsys_initcall(blk_mq_init);