1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions related to sysfs handling
4 */
5#include <linux/kernel.h>
6#include <linux/slab.h>
7#include <linux/module.h>
8#include <linux/bio.h>
9#include <linux/blkdev.h>
10#include <linux/backing-dev.h>
11#include <linux/blktrace_api.h>
12#include <linux/blk-mq.h>
13#include <linux/blk-cgroup.h>
14
15#include "blk.h"
16#include "blk-mq.h"
17#include "blk-mq-debugfs.h"
18#include "blk-wbt.h"
19
20struct queue_sysfs_entry {
21 struct attribute attr;
22 ssize_t (*show)(struct request_queue *, char *);
23 ssize_t (*store)(struct request_queue *, const char *, size_t);
24};
25
26static ssize_t
27queue_var_show(unsigned long var, char *page)
28{
29 return sprintf(page, "%lu\n", var);
30}
31
32static ssize_t
33queue_var_store(unsigned long *var, const char *page, size_t count)
34{
35 int err;
36 unsigned long v;
37
38 err = kstrtoul(page, 10, &v);
39 if (err || v > UINT_MAX)
40 return -EINVAL;
41
42 *var = v;
43
44 return count;
45}
46
47static ssize_t queue_var_store64(s64 *var, const char *page)
48{
49 int err;
50 s64 v;
51
52 err = kstrtos64(page, 10, &v);
53 if (err < 0)
54 return err;
55
56 *var = v;
57 return 0;
58}
59
60static ssize_t queue_requests_show(struct request_queue *q, char *page)
61{
62 return queue_var_show(q->nr_requests, (page));
63}
64
65static ssize_t
66queue_requests_store(struct request_queue *q, const char *page, size_t count)
67{
68 unsigned long nr;
69 int ret, err;
70
71 if (!queue_is_mq(q))
72 return -EINVAL;
73
74 ret = queue_var_store(&nr, page, count);
75 if (ret < 0)
76 return ret;
77
78 if (nr < BLKDEV_MIN_RQ)
79 nr = BLKDEV_MIN_RQ;
80
81 err = blk_mq_update_nr_requests(q, nr);
82 if (err)
83 return err;
84
85 return ret;
86}
87
88static ssize_t queue_ra_show(struct request_queue *q, char *page)
89{
90 unsigned long ra_kb = q->backing_dev_info->ra_pages <<
91 (PAGE_SHIFT - 10);
92
93 return queue_var_show(ra_kb, (page));
94}
95
96static ssize_t
97queue_ra_store(struct request_queue *q, const char *page, size_t count)
98{
99 unsigned long ra_kb;
100 ssize_t ret = queue_var_store(&ra_kb, page, count);
101
102 if (ret < 0)
103 return ret;
104
105 q->backing_dev_info->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
106
107 return ret;
108}
109
110static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
111{
112 int max_sectors_kb = queue_max_sectors(q) >> 1;
113
114 return queue_var_show(max_sectors_kb, (page));
115}
116
117static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
118{
119 return queue_var_show(queue_max_segments(q), (page));
120}
121
122static ssize_t queue_max_discard_segments_show(struct request_queue *q,
123 char *page)
124{
125 return queue_var_show(queue_max_discard_segments(q), (page));
126}
127
128static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
129{
130 return queue_var_show(q->limits.max_integrity_segments, (page));
131}
132
133static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
134{
135 return queue_var_show(queue_max_segment_size(q), (page));
136}
137
138static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
139{
140 return queue_var_show(queue_logical_block_size(q), page);
141}
142
143static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
144{
145 return queue_var_show(queue_physical_block_size(q), page);
146}
147
148static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
149{
150 return queue_var_show(q->limits.chunk_sectors, page);
151}
152
153static ssize_t queue_io_min_show(struct request_queue *q, char *page)
154{
155 return queue_var_show(queue_io_min(q), page);
156}
157
158static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
159{
160 return queue_var_show(queue_io_opt(q), page);
161}
162
163static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
164{
165 return queue_var_show(q->limits.discard_granularity, page);
166}
167
168static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
169{
170
171 return sprintf(page, "%llu\n",
172 (unsigned long long)q->limits.max_hw_discard_sectors << 9);
173}
174
175static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
176{
177 return sprintf(page, "%llu\n",
178 (unsigned long long)q->limits.max_discard_sectors << 9);
179}
180
181static ssize_t queue_discard_max_store(struct request_queue *q,
182 const char *page, size_t count)
183{
184 unsigned long max_discard;
185 ssize_t ret = queue_var_store(&max_discard, page, count);
186
187 if (ret < 0)
188 return ret;
189
190 if (max_discard & (q->limits.discard_granularity - 1))
191 return -EINVAL;
192
193 max_discard >>= 9;
194 if (max_discard > UINT_MAX)
195 return -EINVAL;
196
197 if (max_discard > q->limits.max_hw_discard_sectors)
198 max_discard = q->limits.max_hw_discard_sectors;
199
200 q->limits.max_discard_sectors = max_discard;
201 return ret;
202}
203
204static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
205{
206 return queue_var_show(0, page);
207}
208
209static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
210{
211 return sprintf(page, "%llu\n",
212 (unsigned long long)q->limits.max_write_same_sectors << 9);
213}
214
215static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
216{
217 return sprintf(page, "%llu\n",
218 (unsigned long long)q->limits.max_write_zeroes_sectors << 9);
219}
220
221static ssize_t
222queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
223{
224 unsigned long max_sectors_kb,
225 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
226 page_kb = 1 << (PAGE_SHIFT - 10);
227 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
228
229 if (ret < 0)
230 return ret;
231
232 max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
233 q->limits.max_dev_sectors >> 1);
234
235 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
236 return -EINVAL;
237
238 spin_lock_irq(&q->queue_lock);
239 q->limits.max_sectors = max_sectors_kb << 1;
240 q->backing_dev_info->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
241 spin_unlock_irq(&q->queue_lock);
242
243 return ret;
244}
245
246static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
247{
248 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
249
250 return queue_var_show(max_hw_sectors_kb, (page));
251}
252
253#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
254static ssize_t \
255queue_show_##name(struct request_queue *q, char *page) \
256{ \
257 int bit; \
258 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
259 return queue_var_show(neg ? !bit : bit, page); \
260} \
261static ssize_t \
262queue_store_##name(struct request_queue *q, const char *page, size_t count) \
263{ \
264 unsigned long val; \
265 ssize_t ret; \
266 ret = queue_var_store(&val, page, count); \
267 if (ret < 0) \
268 return ret; \
269 if (neg) \
270 val = !val; \
271 \
272 if (val) \
273 blk_queue_flag_set(QUEUE_FLAG_##flag, q); \
274 else \
275 blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \
276 return ret; \
277}
278
279QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
280QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
281QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
282#undef QUEUE_SYSFS_BIT_FNS
283
284static ssize_t queue_zoned_show(struct request_queue *q, char *page)
285{
286 switch (blk_queue_zoned_model(q)) {
287 case BLK_ZONED_HA:
288 return sprintf(page, "host-aware\n");
289 case BLK_ZONED_HM:
290 return sprintf(page, "host-managed\n");
291 default:
292 return sprintf(page, "none\n");
293 }
294}
295
296static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
297{
298 return queue_var_show(blk_queue_nr_zones(q), page);
299}
300
301static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
302{
303 return queue_var_show((blk_queue_nomerges(q) << 1) |
304 blk_queue_noxmerges(q), page);
305}
306
307static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
308 size_t count)
309{
310 unsigned long nm;
311 ssize_t ret = queue_var_store(&nm, page, count);
312
313 if (ret < 0)
314 return ret;
315
316 blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
317 blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
318 if (nm == 2)
319 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
320 else if (nm)
321 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
322
323 return ret;
324}
325
326static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
327{
328 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
329 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
330
331 return queue_var_show(set << force, page);
332}
333
334static ssize_t
335queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
336{
337 ssize_t ret = -EINVAL;
338#ifdef CONFIG_SMP
339 unsigned long val;
340
341 ret = queue_var_store(&val, page, count);
342 if (ret < 0)
343 return ret;
344
345 if (val == 2) {
346 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
347 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
348 } else if (val == 1) {
349 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
350 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
351 } else if (val == 0) {
352 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
353 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
354 }
355#endif
356 return ret;
357}
358
359static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
360{
361 int val;
362
363 if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
364 val = BLK_MQ_POLL_CLASSIC;
365 else
366 val = q->poll_nsec / 1000;
367
368 return sprintf(page, "%d\n", val);
369}
370
371static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
372 size_t count)
373{
374 int err, val;
375
376 if (!q->mq_ops || !q->mq_ops->poll)
377 return -EINVAL;
378
379 err = kstrtoint(page, 10, &val);
380 if (err < 0)
381 return err;
382
383 if (val == BLK_MQ_POLL_CLASSIC)
384 q->poll_nsec = BLK_MQ_POLL_CLASSIC;
385 else if (val >= 0)
386 q->poll_nsec = val * 1000;
387 else
388 return -EINVAL;
389
390 return count;
391}
392
393static ssize_t queue_poll_show(struct request_queue *q, char *page)
394{
395 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
396}
397
398static ssize_t queue_poll_store(struct request_queue *q, const char *page,
399 size_t count)
400{
401 unsigned long poll_on;
402 ssize_t ret;
403
404 if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL ||
405 !q->tag_set->map[HCTX_TYPE_POLL].nr_queues)
406 return -EINVAL;
407
408 ret = queue_var_store(&poll_on, page, count);
409 if (ret < 0)
410 return ret;
411
412 if (poll_on)
413 blk_queue_flag_set(QUEUE_FLAG_POLL, q);
414 else
415 blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
416
417 return ret;
418}
419
420static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
421{
422 return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout));
423}
424
425static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
426 size_t count)
427{
428 unsigned int val;
429 int err;
430
431 err = kstrtou32(page, 10, &val);
432 if (err || val == 0)
433 return -EINVAL;
434
435 blk_queue_rq_timeout(q, msecs_to_jiffies(val));
436
437 return count;
438}
439
440static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
441{
442 if (!wbt_rq_qos(q))
443 return -EINVAL;
444
445 return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
446}
447
448static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
449 size_t count)
450{
451 struct rq_qos *rqos;
452 ssize_t ret;
453 s64 val;
454
455 ret = queue_var_store64(&val, page);
456 if (ret < 0)
457 return ret;
458 if (val < -1)
459 return -EINVAL;
460
461 rqos = wbt_rq_qos(q);
462 if (!rqos) {
463 ret = wbt_init(q);
464 if (ret)
465 return ret;
466 }
467
468 if (val == -1)
469 val = wbt_default_latency_nsec(q);
470 else if (val >= 0)
471 val *= 1000ULL;
472
473 if (wbt_get_min_lat(q) == val)
474 return count;
475
476 /*
477 * Ensure that the queue is idled, in case the latency update
478 * ends up either enabling or disabling wbt completely. We can't
479 * have IO inflight if that happens.
480 */
481 blk_mq_freeze_queue(q);
482 blk_mq_quiesce_queue(q);
483
484 wbt_set_min_lat(q, val);
485 wbt_update_limits(q);
486
487 blk_mq_unquiesce_queue(q);
488 blk_mq_unfreeze_queue(q);
489
490 return count;
491}
492
493static ssize_t queue_wc_show(struct request_queue *q, char *page)
494{
495 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
496 return sprintf(page, "write back\n");
497
498 return sprintf(page, "write through\n");
499}
500
501static ssize_t queue_wc_store(struct request_queue *q, const char *page,
502 size_t count)
503{
504 int set = -1;
505
506 if (!strncmp(page, "write back", 10))
507 set = 1;
508 else if (!strncmp(page, "write through", 13) ||
509 !strncmp(page, "none", 4))
510 set = 0;
511
512 if (set == -1)
513 return -EINVAL;
514
515 if (set)
516 blk_queue_flag_set(QUEUE_FLAG_WC, q);
517 else
518 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
519
520 return count;
521}
522
523static ssize_t queue_fua_show(struct request_queue *q, char *page)
524{
525 return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
526}
527
528static ssize_t queue_dax_show(struct request_queue *q, char *page)
529{
530 return queue_var_show(blk_queue_dax(q), page);
531}
532
533static struct queue_sysfs_entry queue_requests_entry = {
534 .attr = {.name = "nr_requests", .mode = 0644 },
535 .show = queue_requests_show,
536 .store = queue_requests_store,
537};
538
539static struct queue_sysfs_entry queue_ra_entry = {
540 .attr = {.name = "read_ahead_kb", .mode = 0644 },
541 .show = queue_ra_show,
542 .store = queue_ra_store,
543};
544
545static struct queue_sysfs_entry queue_max_sectors_entry = {
546 .attr = {.name = "max_sectors_kb", .mode = 0644 },
547 .show = queue_max_sectors_show,
548 .store = queue_max_sectors_store,
549};
550
551static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
552 .attr = {.name = "max_hw_sectors_kb", .mode = 0444 },
553 .show = queue_max_hw_sectors_show,
554};
555
556static struct queue_sysfs_entry queue_max_segments_entry = {
557 .attr = {.name = "max_segments", .mode = 0444 },
558 .show = queue_max_segments_show,
559};
560
561static struct queue_sysfs_entry queue_max_discard_segments_entry = {
562 .attr = {.name = "max_discard_segments", .mode = 0444 },
563 .show = queue_max_discard_segments_show,
564};
565
566static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
567 .attr = {.name = "max_integrity_segments", .mode = 0444 },
568 .show = queue_max_integrity_segments_show,
569};
570
571static struct queue_sysfs_entry queue_max_segment_size_entry = {
572 .attr = {.name = "max_segment_size", .mode = 0444 },
573 .show = queue_max_segment_size_show,
574};
575
576static struct queue_sysfs_entry queue_iosched_entry = {
577 .attr = {.name = "scheduler", .mode = 0644 },
578 .show = elv_iosched_show,
579 .store = elv_iosched_store,
580};
581
582static struct queue_sysfs_entry queue_hw_sector_size_entry = {
583 .attr = {.name = "hw_sector_size", .mode = 0444 },
584 .show = queue_logical_block_size_show,
585};
586
587static struct queue_sysfs_entry queue_logical_block_size_entry = {
588 .attr = {.name = "logical_block_size", .mode = 0444 },
589 .show = queue_logical_block_size_show,
590};
591
592static struct queue_sysfs_entry queue_physical_block_size_entry = {
593 .attr = {.name = "physical_block_size", .mode = 0444 },
594 .show = queue_physical_block_size_show,
595};
596
597static struct queue_sysfs_entry queue_chunk_sectors_entry = {
598 .attr = {.name = "chunk_sectors", .mode = 0444 },
599 .show = queue_chunk_sectors_show,
600};
601
602static struct queue_sysfs_entry queue_io_min_entry = {
603 .attr = {.name = "minimum_io_size", .mode = 0444 },
604 .show = queue_io_min_show,
605};
606
607static struct queue_sysfs_entry queue_io_opt_entry = {
608 .attr = {.name = "optimal_io_size", .mode = 0444 },
609 .show = queue_io_opt_show,
610};
611
612static struct queue_sysfs_entry queue_discard_granularity_entry = {
613 .attr = {.name = "discard_granularity", .mode = 0444 },
614 .show = queue_discard_granularity_show,
615};
616
617static struct queue_sysfs_entry queue_discard_max_hw_entry = {
618 .attr = {.name = "discard_max_hw_bytes", .mode = 0444 },
619 .show = queue_discard_max_hw_show,
620};
621
622static struct queue_sysfs_entry queue_discard_max_entry = {
623 .attr = {.name = "discard_max_bytes", .mode = 0644 },
624 .show = queue_discard_max_show,
625 .store = queue_discard_max_store,
626};
627
628static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
629 .attr = {.name = "discard_zeroes_data", .mode = 0444 },
630 .show = queue_discard_zeroes_data_show,
631};
632
633static struct queue_sysfs_entry queue_write_same_max_entry = {
634 .attr = {.name = "write_same_max_bytes", .mode = 0444 },
635 .show = queue_write_same_max_show,
636};
637
638static struct queue_sysfs_entry queue_write_zeroes_max_entry = {
639 .attr = {.name = "write_zeroes_max_bytes", .mode = 0444 },
640 .show = queue_write_zeroes_max_show,
641};
642
643static struct queue_sysfs_entry queue_nonrot_entry = {
644 .attr = {.name = "rotational", .mode = 0644 },
645 .show = queue_show_nonrot,
646 .store = queue_store_nonrot,
647};
648
649static struct queue_sysfs_entry queue_zoned_entry = {
650 .attr = {.name = "zoned", .mode = 0444 },
651 .show = queue_zoned_show,
652};
653
654static struct queue_sysfs_entry queue_nr_zones_entry = {
655 .attr = {.name = "nr_zones", .mode = 0444 },
656 .show = queue_nr_zones_show,
657};
658
659static struct queue_sysfs_entry queue_nomerges_entry = {
660 .attr = {.name = "nomerges", .mode = 0644 },
661 .show = queue_nomerges_show,
662 .store = queue_nomerges_store,
663};
664
665static struct queue_sysfs_entry queue_rq_affinity_entry = {
666 .attr = {.name = "rq_affinity", .mode = 0644 },
667 .show = queue_rq_affinity_show,
668 .store = queue_rq_affinity_store,
669};
670
671static struct queue_sysfs_entry queue_iostats_entry = {
672 .attr = {.name = "iostats", .mode = 0644 },
673 .show = queue_show_iostats,
674 .store = queue_store_iostats,
675};
676
677static struct queue_sysfs_entry queue_random_entry = {
678 .attr = {.name = "add_random", .mode = 0644 },
679 .show = queue_show_random,
680 .store = queue_store_random,
681};
682
683static struct queue_sysfs_entry queue_poll_entry = {
684 .attr = {.name = "io_poll", .mode = 0644 },
685 .show = queue_poll_show,
686 .store = queue_poll_store,
687};
688
689static struct queue_sysfs_entry queue_poll_delay_entry = {
690 .attr = {.name = "io_poll_delay", .mode = 0644 },
691 .show = queue_poll_delay_show,
692 .store = queue_poll_delay_store,
693};
694
695static struct queue_sysfs_entry queue_wc_entry = {
696 .attr = {.name = "write_cache", .mode = 0644 },
697 .show = queue_wc_show,
698 .store = queue_wc_store,
699};
700
701static struct queue_sysfs_entry queue_fua_entry = {
702 .attr = {.name = "fua", .mode = 0444 },
703 .show = queue_fua_show,
704};
705
706static struct queue_sysfs_entry queue_dax_entry = {
707 .attr = {.name = "dax", .mode = 0444 },
708 .show = queue_dax_show,
709};
710
711static struct queue_sysfs_entry queue_io_timeout_entry = {
712 .attr = {.name = "io_timeout", .mode = 0644 },
713 .show = queue_io_timeout_show,
714 .store = queue_io_timeout_store,
715};
716
717static struct queue_sysfs_entry queue_wb_lat_entry = {
718 .attr = {.name = "wbt_lat_usec", .mode = 0644 },
719 .show = queue_wb_lat_show,
720 .store = queue_wb_lat_store,
721};
722
723#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
724static struct queue_sysfs_entry throtl_sample_time_entry = {
725 .attr = {.name = "throttle_sample_time", .mode = 0644 },
726 .show = blk_throtl_sample_time_show,
727 .store = blk_throtl_sample_time_store,
728};
729#endif
730
731static struct attribute *default_attrs[] = {
732 &queue_requests_entry.attr,
733 &queue_ra_entry.attr,
734 &queue_max_hw_sectors_entry.attr,
735 &queue_max_sectors_entry.attr,
736 &queue_max_segments_entry.attr,
737 &queue_max_discard_segments_entry.attr,
738 &queue_max_integrity_segments_entry.attr,
739 &queue_max_segment_size_entry.attr,
740 &queue_iosched_entry.attr,
741 &queue_hw_sector_size_entry.attr,
742 &queue_logical_block_size_entry.attr,
743 &queue_physical_block_size_entry.attr,
744 &queue_chunk_sectors_entry.attr,
745 &queue_io_min_entry.attr,
746 &queue_io_opt_entry.attr,
747 &queue_discard_granularity_entry.attr,
748 &queue_discard_max_entry.attr,
749 &queue_discard_max_hw_entry.attr,
750 &queue_discard_zeroes_data_entry.attr,
751 &queue_write_same_max_entry.attr,
752 &queue_write_zeroes_max_entry.attr,
753 &queue_nonrot_entry.attr,
754 &queue_zoned_entry.attr,
755 &queue_nr_zones_entry.attr,
756 &queue_nomerges_entry.attr,
757 &queue_rq_affinity_entry.attr,
758 &queue_iostats_entry.attr,
759 &queue_random_entry.attr,
760 &queue_poll_entry.attr,
761 &queue_wc_entry.attr,
762 &queue_fua_entry.attr,
763 &queue_dax_entry.attr,
764 &queue_wb_lat_entry.attr,
765 &queue_poll_delay_entry.attr,
766 &queue_io_timeout_entry.attr,
767#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
768 &throtl_sample_time_entry.attr,
769#endif
770 NULL,
771};
772
773#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
774
775static ssize_t
776queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
777{
778 struct queue_sysfs_entry *entry = to_queue(attr);
779 struct request_queue *q =
780 container_of(kobj, struct request_queue, kobj);
781 ssize_t res;
782
783 if (!entry->show)
784 return -EIO;
785 mutex_lock(&q->sysfs_lock);
786 if (blk_queue_dying(q)) {
787 mutex_unlock(&q->sysfs_lock);
788 return -ENOENT;
789 }
790 res = entry->show(q, page);
791 mutex_unlock(&q->sysfs_lock);
792 return res;
793}
794
795static ssize_t
796queue_attr_store(struct kobject *kobj, struct attribute *attr,
797 const char *page, size_t length)
798{
799 struct queue_sysfs_entry *entry = to_queue(attr);
800 struct request_queue *q;
801 ssize_t res;
802
803 if (!entry->store)
804 return -EIO;
805
806 q = container_of(kobj, struct request_queue, kobj);
807 mutex_lock(&q->sysfs_lock);
808 if (blk_queue_dying(q)) {
809 mutex_unlock(&q->sysfs_lock);
810 return -ENOENT;
811 }
812 res = entry->store(q, page, length);
813 mutex_unlock(&q->sysfs_lock);
814 return res;
815}
816
817static void blk_free_queue_rcu(struct rcu_head *rcu_head)
818{
819 struct request_queue *q = container_of(rcu_head, struct request_queue,
820 rcu_head);
821 kmem_cache_free(blk_requestq_cachep, q);
822}
823
824/**
825 * __blk_release_queue - release a request queue
826 * @work: pointer to the release_work member of the request queue to be released
827 *
828 * Description:
829 * This function is called when a block device is being unregistered. The
830 * process of releasing a request queue starts with blk_cleanup_queue, which
831 * set the appropriate flags and then calls blk_put_queue, that decrements
832 * the reference counter of the request queue. Once the reference counter
833 * of the request queue reaches zero, blk_release_queue is called to release
834 * all allocated resources of the request queue.
835 */
836static void __blk_release_queue(struct work_struct *work)
837{
838 struct request_queue *q = container_of(work, typeof(*q), release_work);
839
840 if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
841 blk_stat_remove_callback(q, q->poll_cb);
842 blk_stat_free_callback(q->poll_cb);
843
844 if (!blk_queue_dead(q)) {
845 /*
846 * Last reference was dropped without having called
847 * blk_cleanup_queue().
848 */
849 WARN_ONCE(blk_queue_init_done(q),
850 "request queue %p has been registered but blk_cleanup_queue() has not been called for that queue\n",
851 q);
852 blk_exit_queue(q);
853 }
854
855 WARN(blk_queue_root_blkg(q),
856 "request queue %p is being released but it has not yet been removed from the blkcg controller\n",
857 q);
858
859 blk_free_queue_stats(q->stats);
860
861 blk_queue_free_zone_bitmaps(q);
862
863 if (queue_is_mq(q))
864 blk_mq_release(q);
865
866 blk_trace_shutdown(q);
867
868 if (queue_is_mq(q))
869 blk_mq_debugfs_unregister(q);
870
871 bioset_exit(&q->bio_split);
872
873 ida_simple_remove(&blk_queue_ida, q->id);
874 call_rcu(&q->rcu_head, blk_free_queue_rcu);
875}
876
877static void blk_release_queue(struct kobject *kobj)
878{
879 struct request_queue *q =
880 container_of(kobj, struct request_queue, kobj);
881
882 INIT_WORK(&q->release_work, __blk_release_queue);
883 schedule_work(&q->release_work);
884}
885
886static const struct sysfs_ops queue_sysfs_ops = {
887 .show = queue_attr_show,
888 .store = queue_attr_store,
889};
890
891struct kobj_type blk_queue_ktype = {
892 .sysfs_ops = &queue_sysfs_ops,
893 .default_attrs = default_attrs,
894 .release = blk_release_queue,
895};
896
897/**
898 * blk_register_queue - register a block layer queue with sysfs
899 * @disk: Disk of which the request queue should be registered with sysfs.
900 */
901int blk_register_queue(struct gendisk *disk)
902{
903 int ret;
904 struct device *dev = disk_to_dev(disk);
905 struct request_queue *q = disk->queue;
906
907 if (WARN_ON(!q))
908 return -ENXIO;
909
910 WARN_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags),
911 "%s is registering an already registered queue\n",
912 kobject_name(&dev->kobj));
913 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
914
915 /*
916 * SCSI probing may synchronously create and destroy a lot of
917 * request_queues for non-existent devices. Shutting down a fully
918 * functional queue takes measureable wallclock time as RCU grace
919 * periods are involved. To avoid excessive latency in these
920 * cases, a request_queue starts out in a degraded mode which is
921 * faster to shut down and is made fully functional here as
922 * request_queues for non-existent devices never get registered.
923 */
924 if (!blk_queue_init_done(q)) {
925 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
926 percpu_ref_switch_to_percpu(&q->q_usage_counter);
927 }
928
929 ret = blk_trace_init_sysfs(dev);
930 if (ret)
931 return ret;
932
933 /* Prevent changes through sysfs until registration is completed. */
934 mutex_lock(&q->sysfs_lock);
935
936 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
937 if (ret < 0) {
938 blk_trace_remove_sysfs(dev);
939 goto unlock;
940 }
941
942 if (queue_is_mq(q)) {
943 __blk_mq_register_dev(dev, q);
944 blk_mq_debugfs_register(q);
945 }
946
947 kobject_uevent(&q->kobj, KOBJ_ADD);
948
949 wbt_enable_default(q);
950
951 blk_throtl_register_queue(q);
952
953 if (q->elevator) {
954 ret = elv_register_queue(q);
955 if (ret) {
956 mutex_unlock(&q->sysfs_lock);
957 kobject_uevent(&q->kobj, KOBJ_REMOVE);
958 kobject_del(&q->kobj);
959 blk_trace_remove_sysfs(dev);
960 kobject_put(&dev->kobj);
961 return ret;
962 }
963 }
964 ret = 0;
965unlock:
966 mutex_unlock(&q->sysfs_lock);
967 return ret;
968}
969EXPORT_SYMBOL_GPL(blk_register_queue);
970
971/**
972 * blk_unregister_queue - counterpart of blk_register_queue()
973 * @disk: Disk of which the request queue should be unregistered from sysfs.
974 *
975 * Note: the caller is responsible for guaranteeing that this function is called
976 * after blk_register_queue() has finished.
977 */
978void blk_unregister_queue(struct gendisk *disk)
979{
980 struct request_queue *q = disk->queue;
981
982 if (WARN_ON(!q))
983 return;
984
985 /* Return early if disk->queue was never registered. */
986 if (!test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags))
987 return;
988
989 /*
990 * Since sysfs_remove_dir() prevents adding new directory entries
991 * before removal of existing entries starts, protect against
992 * concurrent elv_iosched_store() calls.
993 */
994 mutex_lock(&q->sysfs_lock);
995
996 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
997
998 /*
999 * Remove the sysfs attributes before unregistering the queue data
1000 * structures that can be modified through sysfs.
1001 */
1002 if (queue_is_mq(q))
1003 blk_mq_unregister_dev(disk_to_dev(disk), q);
1004 mutex_unlock(&q->sysfs_lock);
1005
1006 kobject_uevent(&q->kobj, KOBJ_REMOVE);
1007 kobject_del(&q->kobj);
1008 blk_trace_remove_sysfs(disk_to_dev(disk));
1009
1010 mutex_lock(&q->sysfs_lock);
1011 if (q->elevator)
1012 elv_unregister_queue(q);
1013 mutex_unlock(&q->sysfs_lock);
1014
1015 kobject_put(&disk_to_dev(disk)->kobj);
1016}
1017