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/debugfs.h>
13
14#include "blk.h"
15#include "blk-mq.h"
16#include "blk-mq-debugfs.h"
17#include "blk-mq-sched.h"
18#include "blk-rq-qos.h"
19#include "blk-wbt.h"
20#include "blk-cgroup.h"
21#include "blk-throttle.h"
22
23struct queue_sysfs_entry {
24 struct attribute attr;
25 ssize_t (*show)(struct request_queue *, char *);
26 ssize_t (*store)(struct request_queue *, const char *, size_t);
27};
28
29static ssize_t
30queue_var_show(unsigned long var, char *page)
31{
32 return sprintf(buf: page, fmt: "%lu\n", var);
33}
34
35static ssize_t
36queue_var_store(unsigned long *var, const char *page, size_t count)
37{
38 int err;
39 unsigned long v;
40
41 err = kstrtoul(s: page, base: 10, res: &v);
42 if (err || v > UINT_MAX)
43 return -EINVAL;
44
45 *var = v;
46
47 return count;
48}
49
50static ssize_t queue_requests_show(struct request_queue *q, char *page)
51{
52 return queue_var_show(var: q->nr_requests, page);
53}
54
55static ssize_t
56queue_requests_store(struct request_queue *q, const char *page, size_t count)
57{
58 unsigned long nr;
59 int ret, err;
60
61 if (!queue_is_mq(q))
62 return -EINVAL;
63
64 ret = queue_var_store(var: &nr, page, count);
65 if (ret < 0)
66 return ret;
67
68 if (nr < BLKDEV_MIN_RQ)
69 nr = BLKDEV_MIN_RQ;
70
71 err = blk_mq_update_nr_requests(q, nr);
72 if (err)
73 return err;
74
75 return ret;
76}
77
78static ssize_t queue_ra_show(struct request_queue *q, char *page)
79{
80 unsigned long ra_kb;
81
82 if (!q->disk)
83 return -EINVAL;
84 ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10);
85 return queue_var_show(var: ra_kb, page);
86}
87
88static ssize_t
89queue_ra_store(struct request_queue *q, const char *page, size_t count)
90{
91 unsigned long ra_kb;
92 ssize_t ret;
93
94 if (!q->disk)
95 return -EINVAL;
96 ret = queue_var_store(var: &ra_kb, page, count);
97 if (ret < 0)
98 return ret;
99 q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
100 return ret;
101}
102
103static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
104{
105 int max_sectors_kb = queue_max_sectors(q) >> 1;
106
107 return queue_var_show(var: max_sectors_kb, page);
108}
109
110static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
111{
112 return queue_var_show(var: queue_max_segments(q), page);
113}
114
115static ssize_t queue_max_discard_segments_show(struct request_queue *q,
116 char *page)
117{
118 return queue_var_show(var: queue_max_discard_segments(q), page);
119}
120
121static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
122{
123 return queue_var_show(var: q->limits.max_integrity_segments, page);
124}
125
126static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
127{
128 return queue_var_show(var: queue_max_segment_size(q), page);
129}
130
131static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
132{
133 return queue_var_show(var: queue_logical_block_size(q), page);
134}
135
136static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
137{
138 return queue_var_show(var: queue_physical_block_size(q), page);
139}
140
141static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
142{
143 return queue_var_show(var: q->limits.chunk_sectors, page);
144}
145
146static ssize_t queue_io_min_show(struct request_queue *q, char *page)
147{
148 return queue_var_show(var: queue_io_min(q), page);
149}
150
151static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
152{
153 return queue_var_show(var: queue_io_opt(q), page);
154}
155
156static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
157{
158 return queue_var_show(var: q->limits.discard_granularity, page);
159}
160
161static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
162{
163
164 return sprintf(buf: page, fmt: "%llu\n",
165 (unsigned long long)q->limits.max_hw_discard_sectors << 9);
166}
167
168static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
169{
170 return sprintf(buf: page, fmt: "%llu\n",
171 (unsigned long long)q->limits.max_discard_sectors << 9);
172}
173
174static ssize_t queue_discard_max_store(struct request_queue *q,
175 const char *page, size_t count)
176{
177 unsigned long max_discard;
178 ssize_t ret = queue_var_store(var: &max_discard, page, count);
179
180 if (ret < 0)
181 return ret;
182
183 if (max_discard & (q->limits.discard_granularity - 1))
184 return -EINVAL;
185
186 max_discard >>= 9;
187 if (max_discard > UINT_MAX)
188 return -EINVAL;
189
190 if (max_discard > q->limits.max_hw_discard_sectors)
191 max_discard = q->limits.max_hw_discard_sectors;
192
193 q->limits.max_discard_sectors = max_discard;
194 return ret;
195}
196
197static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
198{
199 return queue_var_show(var: 0, page);
200}
201
202static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
203{
204 return queue_var_show(var: 0, page);
205}
206
207static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
208{
209 return sprintf(buf: page, fmt: "%llu\n",
210 (unsigned long long)q->limits.max_write_zeroes_sectors << 9);
211}
212
213static ssize_t queue_zone_write_granularity_show(struct request_queue *q,
214 char *page)
215{
216 return queue_var_show(var: queue_zone_write_granularity(q), page);
217}
218
219static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
220{
221 unsigned long long max_sectors = q->limits.max_zone_append_sectors;
222
223 return sprintf(buf: page, fmt: "%llu\n", max_sectors << SECTOR_SHIFT);
224}
225
226static ssize_t
227queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
228{
229 unsigned long var;
230 unsigned int max_sectors_kb,
231 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
232 page_kb = 1 << (PAGE_SHIFT - 10);
233 ssize_t ret = queue_var_store(var: &var, page, count);
234
235 if (ret < 0)
236 return ret;
237
238 max_sectors_kb = (unsigned int)var;
239 max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb,
240 q->limits.max_dev_sectors >> 1);
241 if (max_sectors_kb == 0) {
242 q->limits.max_user_sectors = 0;
243 max_sectors_kb = min(max_hw_sectors_kb,
244 BLK_DEF_MAX_SECTORS >> 1);
245 } else {
246 if (max_sectors_kb > max_hw_sectors_kb ||
247 max_sectors_kb < page_kb)
248 return -EINVAL;
249 q->limits.max_user_sectors = max_sectors_kb << 1;
250 }
251
252 spin_lock_irq(lock: &q->queue_lock);
253 q->limits.max_sectors = max_sectors_kb << 1;
254 if (q->disk)
255 q->disk->bdi->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
256 spin_unlock_irq(lock: &q->queue_lock);
257
258 return ret;
259}
260
261static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
262{
263 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
264
265 return queue_var_show(var: max_hw_sectors_kb, page);
266}
267
268static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page)
269{
270 return queue_var_show(var: q->limits.virt_boundary_mask, page);
271}
272
273static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
274{
275 return queue_var_show(var: queue_dma_alignment(q), page);
276}
277
278#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
279static ssize_t \
280queue_##name##_show(struct request_queue *q, char *page) \
281{ \
282 int bit; \
283 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
284 return queue_var_show(neg ? !bit : bit, page); \
285} \
286static ssize_t \
287queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
288{ \
289 unsigned long val; \
290 ssize_t ret; \
291 ret = queue_var_store(&val, page, count); \
292 if (ret < 0) \
293 return ret; \
294 if (neg) \
295 val = !val; \
296 \
297 if (val) \
298 blk_queue_flag_set(QUEUE_FLAG_##flag, q); \
299 else \
300 blk_queue_flag_clear(QUEUE_FLAG_##flag, q); \
301 return ret; \
302}
303
304QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
305QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
306QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
307QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
308#undef QUEUE_SYSFS_BIT_FNS
309
310static ssize_t queue_zoned_show(struct request_queue *q, char *page)
311{
312 switch (blk_queue_zoned_model(q)) {
313 case BLK_ZONED_HA:
314 return sprintf(buf: page, fmt: "host-aware\n");
315 case BLK_ZONED_HM:
316 return sprintf(buf: page, fmt: "host-managed\n");
317 default:
318 return sprintf(buf: page, fmt: "none\n");
319 }
320}
321
322static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
323{
324 return queue_var_show(var: disk_nr_zones(disk: q->disk), page);
325}
326
327static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
328{
329 return queue_var_show(var: bdev_max_open_zones(bdev: q->disk->part0), page);
330}
331
332static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
333{
334 return queue_var_show(var: bdev_max_active_zones(bdev: q->disk->part0), page);
335}
336
337static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
338{
339 return queue_var_show(var: (blk_queue_nomerges(q) << 1) |
340 blk_queue_noxmerges(q), page);
341}
342
343static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
344 size_t count)
345{
346 unsigned long nm;
347 ssize_t ret = queue_var_store(var: &nm, page, count);
348
349 if (ret < 0)
350 return ret;
351
352 blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
353 blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
354 if (nm == 2)
355 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
356 else if (nm)
357 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
358
359 return ret;
360}
361
362static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
363{
364 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
365 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
366
367 return queue_var_show(var: set << force, page);
368}
369
370static ssize_t
371queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
372{
373 ssize_t ret = -EINVAL;
374#ifdef CONFIG_SMP
375 unsigned long val;
376
377 ret = queue_var_store(var: &val, page, count);
378 if (ret < 0)
379 return ret;
380
381 if (val == 2) {
382 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
383 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
384 } else if (val == 1) {
385 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
386 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
387 } else if (val == 0) {
388 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
389 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
390 }
391#endif
392 return ret;
393}
394
395static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
396{
397 return sprintf(buf: page, fmt: "%d\n", -1);
398}
399
400static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
401 size_t count)
402{
403 return count;
404}
405
406static ssize_t queue_poll_show(struct request_queue *q, char *page)
407{
408 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
409}
410
411static ssize_t queue_poll_store(struct request_queue *q, const char *page,
412 size_t count)
413{
414 if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
415 return -EINVAL;
416 pr_info_ratelimited("writes to the poll attribute are ignored.\n");
417 pr_info_ratelimited("please use driver specific parameters instead.\n");
418 return count;
419}
420
421static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
422{
423 return sprintf(buf: page, fmt: "%u\n", jiffies_to_msecs(j: q->rq_timeout));
424}
425
426static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
427 size_t count)
428{
429 unsigned int val;
430 int err;
431
432 err = kstrtou32(s: page, base: 10, res: &val);
433 if (err || val == 0)
434 return -EINVAL;
435
436 blk_queue_rq_timeout(q, msecs_to_jiffies(m: val));
437
438 return count;
439}
440
441static ssize_t queue_wc_show(struct request_queue *q, char *page)
442{
443 if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
444 return sprintf(buf: page, fmt: "write back\n");
445
446 return sprintf(buf: page, fmt: "write through\n");
447}
448
449static ssize_t queue_wc_store(struct request_queue *q, const char *page,
450 size_t count)
451{
452 if (!strncmp(page, "write back", 10)) {
453 if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags))
454 return -EINVAL;
455 blk_queue_flag_set(QUEUE_FLAG_WC, q);
456 } else if (!strncmp(page, "write through", 13) ||
457 !strncmp(page, "none", 4)) {
458 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
459 } else {
460 return -EINVAL;
461 }
462
463 return count;
464}
465
466static ssize_t queue_fua_show(struct request_queue *q, char *page)
467{
468 return sprintf(buf: page, fmt: "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
469}
470
471static ssize_t queue_dax_show(struct request_queue *q, char *page)
472{
473 return queue_var_show(blk_queue_dax(q), page);
474}
475
476#define QUEUE_RO_ENTRY(_prefix, _name) \
477static struct queue_sysfs_entry _prefix##_entry = { \
478 .attr = { .name = _name, .mode = 0444 }, \
479 .show = _prefix##_show, \
480};
481
482#define QUEUE_RW_ENTRY(_prefix, _name) \
483static struct queue_sysfs_entry _prefix##_entry = { \
484 .attr = { .name = _name, .mode = 0644 }, \
485 .show = _prefix##_show, \
486 .store = _prefix##_store, \
487};
488
489QUEUE_RW_ENTRY(queue_requests, "nr_requests");
490QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");
491QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
492QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
493QUEUE_RO_ENTRY(queue_max_segments, "max_segments");
494QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");
495QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size");
496QUEUE_RW_ENTRY(elv_iosched, "scheduler");
497
498QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size");
499QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size");
500QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors");
501QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size");
502QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size");
503
504QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments");
505QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity");
506QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes");
507QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes");
508QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data");
509
510QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes");
511QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes");
512QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes");
513QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity");
514
515QUEUE_RO_ENTRY(queue_zoned, "zoned");
516QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones");
517QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones");
518QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones");
519
520QUEUE_RW_ENTRY(queue_nomerges, "nomerges");
521QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity");
522QUEUE_RW_ENTRY(queue_poll, "io_poll");
523QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay");
524QUEUE_RW_ENTRY(queue_wc, "write_cache");
525QUEUE_RO_ENTRY(queue_fua, "fua");
526QUEUE_RO_ENTRY(queue_dax, "dax");
527QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
528QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
529QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment");
530
531#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
532QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time");
533#endif
534
535/* legacy alias for logical_block_size: */
536static struct queue_sysfs_entry queue_hw_sector_size_entry = {
537 .attr = {.name = "hw_sector_size", .mode = 0444 },
538 .show = queue_logical_block_size_show,
539};
540
541QUEUE_RW_ENTRY(queue_nonrot, "rotational");
542QUEUE_RW_ENTRY(queue_iostats, "iostats");
543QUEUE_RW_ENTRY(queue_random, "add_random");
544QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
545
546#ifdef CONFIG_BLK_WBT
547static ssize_t queue_var_store64(s64 *var, const char *page)
548{
549 int err;
550 s64 v;
551
552 err = kstrtos64(s: page, base: 10, res: &v);
553 if (err < 0)
554 return err;
555
556 *var = v;
557 return 0;
558}
559
560static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
561{
562 if (!wbt_rq_qos(q))
563 return -EINVAL;
564
565 if (wbt_disabled(q))
566 return sprintf(buf: page, fmt: "0\n");
567
568 return sprintf(buf: page, fmt: "%llu\n", div_u64(dividend: wbt_get_min_lat(q), divisor: 1000));
569}
570
571static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
572 size_t count)
573{
574 struct rq_qos *rqos;
575 ssize_t ret;
576 s64 val;
577
578 ret = queue_var_store64(var: &val, page);
579 if (ret < 0)
580 return ret;
581 if (val < -1)
582 return -EINVAL;
583
584 rqos = wbt_rq_qos(q);
585 if (!rqos) {
586 ret = wbt_init(disk: q->disk);
587 if (ret)
588 return ret;
589 }
590
591 if (val == -1)
592 val = wbt_default_latency_nsec(q);
593 else if (val >= 0)
594 val *= 1000ULL;
595
596 if (wbt_get_min_lat(q) == val)
597 return count;
598
599 /*
600 * Ensure that the queue is idled, in case the latency update
601 * ends up either enabling or disabling wbt completely. We can't
602 * have IO inflight if that happens.
603 */
604 blk_mq_freeze_queue(q);
605 blk_mq_quiesce_queue(q);
606
607 wbt_set_min_lat(q, val);
608
609 blk_mq_unquiesce_queue(q);
610 blk_mq_unfreeze_queue(q);
611
612 return count;
613}
614
615QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec");
616#endif
617
618static struct attribute *queue_attrs[] = {
619 &queue_ra_entry.attr,
620 &queue_max_hw_sectors_entry.attr,
621 &queue_max_sectors_entry.attr,
622 &queue_max_segments_entry.attr,
623 &queue_max_discard_segments_entry.attr,
624 &queue_max_integrity_segments_entry.attr,
625 &queue_max_segment_size_entry.attr,
626 &queue_hw_sector_size_entry.attr,
627 &queue_logical_block_size_entry.attr,
628 &queue_physical_block_size_entry.attr,
629 &queue_chunk_sectors_entry.attr,
630 &queue_io_min_entry.attr,
631 &queue_io_opt_entry.attr,
632 &queue_discard_granularity_entry.attr,
633 &queue_discard_max_entry.attr,
634 &queue_discard_max_hw_entry.attr,
635 &queue_discard_zeroes_data_entry.attr,
636 &queue_write_same_max_entry.attr,
637 &queue_write_zeroes_max_entry.attr,
638 &queue_zone_append_max_entry.attr,
639 &queue_zone_write_granularity_entry.attr,
640 &queue_nonrot_entry.attr,
641 &queue_zoned_entry.attr,
642 &queue_nr_zones_entry.attr,
643 &queue_max_open_zones_entry.attr,
644 &queue_max_active_zones_entry.attr,
645 &queue_nomerges_entry.attr,
646 &queue_iostats_entry.attr,
647 &queue_stable_writes_entry.attr,
648 &queue_random_entry.attr,
649 &queue_poll_entry.attr,
650 &queue_wc_entry.attr,
651 &queue_fua_entry.attr,
652 &queue_dax_entry.attr,
653 &queue_poll_delay_entry.attr,
654#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
655 &blk_throtl_sample_time_entry.attr,
656#endif
657 &queue_virt_boundary_mask_entry.attr,
658 &queue_dma_alignment_entry.attr,
659 NULL,
660};
661
662static struct attribute *blk_mq_queue_attrs[] = {
663 &queue_requests_entry.attr,
664 &elv_iosched_entry.attr,
665 &queue_rq_affinity_entry.attr,
666 &queue_io_timeout_entry.attr,
667#ifdef CONFIG_BLK_WBT
668 &queue_wb_lat_entry.attr,
669#endif
670 NULL,
671};
672
673static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
674 int n)
675{
676 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
677 struct request_queue *q = disk->queue;
678
679 if ((attr == &queue_max_open_zones_entry.attr ||
680 attr == &queue_max_active_zones_entry.attr) &&
681 !blk_queue_is_zoned(q))
682 return 0;
683
684 return attr->mode;
685}
686
687static umode_t blk_mq_queue_attr_visible(struct kobject *kobj,
688 struct attribute *attr, int n)
689{
690 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
691 struct request_queue *q = disk->queue;
692
693 if (!queue_is_mq(q))
694 return 0;
695
696 if (attr == &queue_io_timeout_entry.attr && !q->mq_ops->timeout)
697 return 0;
698
699 return attr->mode;
700}
701
702static struct attribute_group queue_attr_group = {
703 .attrs = queue_attrs,
704 .is_visible = queue_attr_visible,
705};
706
707static struct attribute_group blk_mq_queue_attr_group = {
708 .attrs = blk_mq_queue_attrs,
709 .is_visible = blk_mq_queue_attr_visible,
710};
711
712#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
713
714static ssize_t
715queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
716{
717 struct queue_sysfs_entry *entry = to_queue(attr);
718 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
719 struct request_queue *q = disk->queue;
720 ssize_t res;
721
722 if (!entry->show)
723 return -EIO;
724 mutex_lock(&q->sysfs_lock);
725 res = entry->show(q, page);
726 mutex_unlock(lock: &q->sysfs_lock);
727 return res;
728}
729
730static ssize_t
731queue_attr_store(struct kobject *kobj, struct attribute *attr,
732 const char *page, size_t length)
733{
734 struct queue_sysfs_entry *entry = to_queue(attr);
735 struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
736 struct request_queue *q = disk->queue;
737 ssize_t res;
738
739 if (!entry->store)
740 return -EIO;
741
742 mutex_lock(&q->sysfs_lock);
743 res = entry->store(q, page, length);
744 mutex_unlock(lock: &q->sysfs_lock);
745 return res;
746}
747
748static const struct sysfs_ops queue_sysfs_ops = {
749 .show = queue_attr_show,
750 .store = queue_attr_store,
751};
752
753static const struct attribute_group *blk_queue_attr_groups[] = {
754 &queue_attr_group,
755 &blk_mq_queue_attr_group,
756 NULL
757};
758
759static void blk_queue_release(struct kobject *kobj)
760{
761 /* nothing to do here, all data is associated with the parent gendisk */
762}
763
764static const struct kobj_type blk_queue_ktype = {
765 .default_groups = blk_queue_attr_groups,
766 .sysfs_ops = &queue_sysfs_ops,
767 .release = blk_queue_release,
768};
769
770static void blk_debugfs_remove(struct gendisk *disk)
771{
772 struct request_queue *q = disk->queue;
773
774 mutex_lock(&q->debugfs_mutex);
775 blk_trace_shutdown(q);
776 debugfs_remove_recursive(dentry: q->debugfs_dir);
777 q->debugfs_dir = NULL;
778 q->sched_debugfs_dir = NULL;
779 q->rqos_debugfs_dir = NULL;
780 mutex_unlock(lock: &q->debugfs_mutex);
781}
782
783/**
784 * blk_register_queue - register a block layer queue with sysfs
785 * @disk: Disk of which the request queue should be registered with sysfs.
786 */
787int blk_register_queue(struct gendisk *disk)
788{
789 struct request_queue *q = disk->queue;
790 int ret;
791
792 mutex_lock(&q->sysfs_dir_lock);
793 kobject_init(kobj: &disk->queue_kobj, ktype: &blk_queue_ktype);
794 ret = kobject_add(kobj: &disk->queue_kobj, parent: &disk_to_dev(disk)->kobj, fmt: "queue");
795 if (ret < 0)
796 goto out_put_queue_kobj;
797
798 if (queue_is_mq(q)) {
799 ret = blk_mq_sysfs_register(disk);
800 if (ret)
801 goto out_put_queue_kobj;
802 }
803 mutex_lock(&q->sysfs_lock);
804
805 mutex_lock(&q->debugfs_mutex);
806 q->debugfs_dir = debugfs_create_dir(name: disk->disk_name, parent: blk_debugfs_root);
807 if (queue_is_mq(q))
808 blk_mq_debugfs_register(q);
809 mutex_unlock(lock: &q->debugfs_mutex);
810
811 ret = disk_register_independent_access_ranges(disk);
812 if (ret)
813 goto out_debugfs_remove;
814
815 if (q->elevator) {
816 ret = elv_register_queue(q, uevent: false);
817 if (ret)
818 goto out_unregister_ia_ranges;
819 }
820
821 ret = blk_crypto_sysfs_register(disk);
822 if (ret)
823 goto out_elv_unregister;
824
825 blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
826 wbt_enable_default(disk);
827 blk_throtl_register(disk);
828
829 /* Now everything is ready and send out KOBJ_ADD uevent */
830 kobject_uevent(kobj: &disk->queue_kobj, action: KOBJ_ADD);
831 if (q->elevator)
832 kobject_uevent(kobj: &q->elevator->kobj, action: KOBJ_ADD);
833 mutex_unlock(lock: &q->sysfs_lock);
834 mutex_unlock(lock: &q->sysfs_dir_lock);
835
836 /*
837 * SCSI probing may synchronously create and destroy a lot of
838 * request_queues for non-existent devices. Shutting down a fully
839 * functional queue takes measureable wallclock time as RCU grace
840 * periods are involved. To avoid excessive latency in these
841 * cases, a request_queue starts out in a degraded mode which is
842 * faster to shut down and is made fully functional here as
843 * request_queues for non-existent devices never get registered.
844 */
845 if (!blk_queue_init_done(q)) {
846 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
847 percpu_ref_switch_to_percpu(ref: &q->q_usage_counter);
848 }
849
850 return ret;
851
852out_elv_unregister:
853 elv_unregister_queue(q);
854out_unregister_ia_ranges:
855 disk_unregister_independent_access_ranges(disk);
856out_debugfs_remove:
857 blk_debugfs_remove(disk);
858 mutex_unlock(lock: &q->sysfs_lock);
859out_put_queue_kobj:
860 kobject_put(kobj: &disk->queue_kobj);
861 mutex_unlock(lock: &q->sysfs_dir_lock);
862 return ret;
863}
864
865/**
866 * blk_unregister_queue - counterpart of blk_register_queue()
867 * @disk: Disk of which the request queue should be unregistered from sysfs.
868 *
869 * Note: the caller is responsible for guaranteeing that this function is called
870 * after blk_register_queue() has finished.
871 */
872void blk_unregister_queue(struct gendisk *disk)
873{
874 struct request_queue *q = disk->queue;
875
876 if (WARN_ON(!q))
877 return;
878
879 /* Return early if disk->queue was never registered. */
880 if (!blk_queue_registered(q))
881 return;
882
883 /*
884 * Since sysfs_remove_dir() prevents adding new directory entries
885 * before removal of existing entries starts, protect against
886 * concurrent elv_iosched_store() calls.
887 */
888 mutex_lock(&q->sysfs_lock);
889 blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
890 mutex_unlock(lock: &q->sysfs_lock);
891
892 mutex_lock(&q->sysfs_dir_lock);
893 /*
894 * Remove the sysfs attributes before unregistering the queue data
895 * structures that can be modified through sysfs.
896 */
897 if (queue_is_mq(q))
898 blk_mq_sysfs_unregister(disk);
899 blk_crypto_sysfs_unregister(disk);
900
901 mutex_lock(&q->sysfs_lock);
902 elv_unregister_queue(q);
903 disk_unregister_independent_access_ranges(disk);
904 mutex_unlock(lock: &q->sysfs_lock);
905
906 /* Now that we've deleted all child objects, we can delete the queue. */
907 kobject_uevent(kobj: &disk->queue_kobj, action: KOBJ_REMOVE);
908 kobject_del(kobj: &disk->queue_kobj);
909 mutex_unlock(lock: &q->sysfs_dir_lock);
910
911 blk_debugfs_remove(disk);
912}
913

source code of linux/block/blk-sysfs.c