Merge tag 'docs-6.4-2' of git://git.lwn.net/linux
[linux.git] / block / blk-sysfs.c
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
23 struct 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
29 static ssize_t
30 queue_var_show(unsigned long var, char *page)
31 {
32         return sprintf(page, "%lu\n", var);
33 }
34
35 static ssize_t
36 queue_var_store(unsigned long *var, const char *page, size_t count)
37 {
38         int err;
39         unsigned long v;
40
41         err = kstrtoul(page, 10, &v);
42         if (err || v > UINT_MAX)
43                 return -EINVAL;
44
45         *var = v;
46
47         return count;
48 }
49
50 static ssize_t queue_var_store64(s64 *var, const char *page)
51 {
52         int err;
53         s64 v;
54
55         err = kstrtos64(page, 10, &v);
56         if (err < 0)
57                 return err;
58
59         *var = v;
60         return 0;
61 }
62
63 static ssize_t queue_requests_show(struct request_queue *q, char *page)
64 {
65         return queue_var_show(q->nr_requests, page);
66 }
67
68 static ssize_t
69 queue_requests_store(struct request_queue *q, const char *page, size_t count)
70 {
71         unsigned long nr;
72         int ret, err;
73
74         if (!queue_is_mq(q))
75                 return -EINVAL;
76
77         ret = queue_var_store(&nr, page, count);
78         if (ret < 0)
79                 return ret;
80
81         if (nr < BLKDEV_MIN_RQ)
82                 nr = BLKDEV_MIN_RQ;
83
84         err = blk_mq_update_nr_requests(q, nr);
85         if (err)
86                 return err;
87
88         return ret;
89 }
90
91 static ssize_t queue_ra_show(struct request_queue *q, char *page)
92 {
93         unsigned long ra_kb;
94
95         if (!q->disk)
96                 return -EINVAL;
97         ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10);
98         return queue_var_show(ra_kb, page);
99 }
100
101 static ssize_t
102 queue_ra_store(struct request_queue *q, const char *page, size_t count)
103 {
104         unsigned long ra_kb;
105         ssize_t ret;
106
107         if (!q->disk)
108                 return -EINVAL;
109         ret = queue_var_store(&ra_kb, page, count);
110         if (ret < 0)
111                 return ret;
112         q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
113         return ret;
114 }
115
116 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
117 {
118         int max_sectors_kb = queue_max_sectors(q) >> 1;
119
120         return queue_var_show(max_sectors_kb, page);
121 }
122
123 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
124 {
125         return queue_var_show(queue_max_segments(q), page);
126 }
127
128 static ssize_t queue_max_discard_segments_show(struct request_queue *q,
129                 char *page)
130 {
131         return queue_var_show(queue_max_discard_segments(q), page);
132 }
133
134 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
135 {
136         return queue_var_show(q->limits.max_integrity_segments, page);
137 }
138
139 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
140 {
141         return queue_var_show(queue_max_segment_size(q), page);
142 }
143
144 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
145 {
146         return queue_var_show(queue_logical_block_size(q), page);
147 }
148
149 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
150 {
151         return queue_var_show(queue_physical_block_size(q), page);
152 }
153
154 static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
155 {
156         return queue_var_show(q->limits.chunk_sectors, page);
157 }
158
159 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
160 {
161         return queue_var_show(queue_io_min(q), page);
162 }
163
164 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
165 {
166         return queue_var_show(queue_io_opt(q), page);
167 }
168
169 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
170 {
171         return queue_var_show(q->limits.discard_granularity, page);
172 }
173
174 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
175 {
176
177         return sprintf(page, "%llu\n",
178                 (unsigned long long)q->limits.max_hw_discard_sectors << 9);
179 }
180
181 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
182 {
183         return sprintf(page, "%llu\n",
184                        (unsigned long long)q->limits.max_discard_sectors << 9);
185 }
186
187 static ssize_t queue_discard_max_store(struct request_queue *q,
188                                        const char *page, size_t count)
189 {
190         unsigned long max_discard;
191         ssize_t ret = queue_var_store(&max_discard, page, count);
192
193         if (ret < 0)
194                 return ret;
195
196         if (max_discard & (q->limits.discard_granularity - 1))
197                 return -EINVAL;
198
199         max_discard >>= 9;
200         if (max_discard > UINT_MAX)
201                 return -EINVAL;
202
203         if (max_discard > q->limits.max_hw_discard_sectors)
204                 max_discard = q->limits.max_hw_discard_sectors;
205
206         q->limits.max_discard_sectors = max_discard;
207         return ret;
208 }
209
210 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
211 {
212         return queue_var_show(0, page);
213 }
214
215 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
216 {
217         return queue_var_show(0, page);
218 }
219
220 static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
221 {
222         return sprintf(page, "%llu\n",
223                 (unsigned long long)q->limits.max_write_zeroes_sectors << 9);
224 }
225
226 static ssize_t queue_zone_write_granularity_show(struct request_queue *q,
227                                                  char *page)
228 {
229         return queue_var_show(queue_zone_write_granularity(q), page);
230 }
231
232 static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
233 {
234         unsigned long long max_sectors = q->limits.max_zone_append_sectors;
235
236         return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT);
237 }
238
239 static ssize_t
240 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
241 {
242         unsigned long var;
243         unsigned int max_sectors_kb,
244                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
245                         page_kb = 1 << (PAGE_SHIFT - 10);
246         ssize_t ret = queue_var_store(&var, page, count);
247
248         if (ret < 0)
249                 return ret;
250
251         max_sectors_kb = (unsigned int)var;
252         max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb,
253                                          q->limits.max_dev_sectors >> 1);
254         if (max_sectors_kb == 0) {
255                 q->limits.max_user_sectors = 0;
256                 max_sectors_kb = min(max_hw_sectors_kb,
257                                      BLK_DEF_MAX_SECTORS >> 1);
258         } else {
259                 if (max_sectors_kb > max_hw_sectors_kb ||
260                     max_sectors_kb < page_kb)
261                         return -EINVAL;
262                 q->limits.max_user_sectors = max_sectors_kb << 1;
263         }
264
265         spin_lock_irq(&q->queue_lock);
266         q->limits.max_sectors = max_sectors_kb << 1;
267         if (q->disk)
268                 q->disk->bdi->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
269         spin_unlock_irq(&q->queue_lock);
270
271         return ret;
272 }
273
274 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
275 {
276         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
277
278         return queue_var_show(max_hw_sectors_kb, page);
279 }
280
281 static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page)
282 {
283         return queue_var_show(q->limits.virt_boundary_mask, page);
284 }
285
286 static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
287 {
288         return queue_var_show(queue_dma_alignment(q), page);
289 }
290
291 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
292 static ssize_t                                                          \
293 queue_##name##_show(struct request_queue *q, char *page)                \
294 {                                                                       \
295         int bit;                                                        \
296         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
297         return queue_var_show(neg ? !bit : bit, page);                  \
298 }                                                                       \
299 static ssize_t                                                          \
300 queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
301 {                                                                       \
302         unsigned long val;                                              \
303         ssize_t ret;                                                    \
304         ret = queue_var_store(&val, page, count);                       \
305         if (ret < 0)                                                    \
306                  return ret;                                            \
307         if (neg)                                                        \
308                 val = !val;                                             \
309                                                                         \
310         if (val)                                                        \
311                 blk_queue_flag_set(QUEUE_FLAG_##flag, q);               \
312         else                                                            \
313                 blk_queue_flag_clear(QUEUE_FLAG_##flag, q);             \
314         return ret;                                                     \
315 }
316
317 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
318 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
319 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
320 QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
321 #undef QUEUE_SYSFS_BIT_FNS
322
323 static ssize_t queue_zoned_show(struct request_queue *q, char *page)
324 {
325         switch (blk_queue_zoned_model(q)) {
326         case BLK_ZONED_HA:
327                 return sprintf(page, "host-aware\n");
328         case BLK_ZONED_HM:
329                 return sprintf(page, "host-managed\n");
330         default:
331                 return sprintf(page, "none\n");
332         }
333 }
334
335 static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
336 {
337         return queue_var_show(disk_nr_zones(q->disk), page);
338 }
339
340 static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
341 {
342         return queue_var_show(bdev_max_open_zones(q->disk->part0), page);
343 }
344
345 static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
346 {
347         return queue_var_show(bdev_max_active_zones(q->disk->part0), page);
348 }
349
350 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
351 {
352         return queue_var_show((blk_queue_nomerges(q) << 1) |
353                                blk_queue_noxmerges(q), page);
354 }
355
356 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
357                                     size_t count)
358 {
359         unsigned long nm;
360         ssize_t ret = queue_var_store(&nm, page, count);
361
362         if (ret < 0)
363                 return ret;
364
365         blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
366         blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
367         if (nm == 2)
368                 blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
369         else if (nm)
370                 blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
371
372         return ret;
373 }
374
375 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
376 {
377         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
378         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
379
380         return queue_var_show(set << force, page);
381 }
382
383 static ssize_t
384 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
385 {
386         ssize_t ret = -EINVAL;
387 #ifdef CONFIG_SMP
388         unsigned long val;
389
390         ret = queue_var_store(&val, page, count);
391         if (ret < 0)
392                 return ret;
393
394         if (val == 2) {
395                 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
396                 blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
397         } else if (val == 1) {
398                 blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
399                 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
400         } else if (val == 0) {
401                 blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
402                 blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
403         }
404 #endif
405         return ret;
406 }
407
408 static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
409 {
410         return sprintf(page, "%d\n", -1);
411 }
412
413 static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
414                                 size_t count)
415 {
416         return count;
417 }
418
419 static ssize_t queue_poll_show(struct request_queue *q, char *page)
420 {
421         return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
422 }
423
424 static ssize_t queue_poll_store(struct request_queue *q, const char *page,
425                                 size_t count)
426 {
427         if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
428                 return -EINVAL;
429         pr_info_ratelimited("writes to the poll attribute are ignored.\n");
430         pr_info_ratelimited("please use driver specific parameters instead.\n");
431         return count;
432 }
433
434 static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
435 {
436         return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout));
437 }
438
439 static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
440                                   size_t count)
441 {
442         unsigned int val;
443         int err;
444
445         err = kstrtou32(page, 10, &val);
446         if (err || val == 0)
447                 return -EINVAL;
448
449         blk_queue_rq_timeout(q, msecs_to_jiffies(val));
450
451         return count;
452 }
453
454 static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
455 {
456         if (!wbt_rq_qos(q))
457                 return -EINVAL;
458
459         if (wbt_disabled(q))
460                 return sprintf(page, "0\n");
461
462         return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
463 }
464
465 static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
466                                   size_t count)
467 {
468         struct rq_qos *rqos;
469         ssize_t ret;
470         s64 val;
471
472         ret = queue_var_store64(&val, page);
473         if (ret < 0)
474                 return ret;
475         if (val < -1)
476                 return -EINVAL;
477
478         rqos = wbt_rq_qos(q);
479         if (!rqos) {
480                 ret = wbt_init(q->disk);
481                 if (ret)
482                         return ret;
483         }
484
485         if (val == -1)
486                 val = wbt_default_latency_nsec(q);
487         else if (val >= 0)
488                 val *= 1000ULL;
489
490         if (wbt_get_min_lat(q) == val)
491                 return count;
492
493         /*
494          * Ensure that the queue is idled, in case the latency update
495          * ends up either enabling or disabling wbt completely. We can't
496          * have IO inflight if that happens.
497          */
498         blk_mq_freeze_queue(q);
499         blk_mq_quiesce_queue(q);
500
501         wbt_set_min_lat(q, val);
502
503         blk_mq_unquiesce_queue(q);
504         blk_mq_unfreeze_queue(q);
505
506         return count;
507 }
508
509 static ssize_t queue_wc_show(struct request_queue *q, char *page)
510 {
511         if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
512                 return sprintf(page, "write back\n");
513
514         return sprintf(page, "write through\n");
515 }
516
517 static ssize_t queue_wc_store(struct request_queue *q, const char *page,
518                               size_t count)
519 {
520         int set = -1;
521
522         if (!strncmp(page, "write back", 10))
523                 set = 1;
524         else if (!strncmp(page, "write through", 13) ||
525                  !strncmp(page, "none", 4))
526                 set = 0;
527
528         if (set == -1)
529                 return -EINVAL;
530
531         if (set)
532                 blk_queue_flag_set(QUEUE_FLAG_WC, q);
533         else
534                 blk_queue_flag_clear(QUEUE_FLAG_WC, q);
535
536         return count;
537 }
538
539 static ssize_t queue_fua_show(struct request_queue *q, char *page)
540 {
541         return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
542 }
543
544 static ssize_t queue_dax_show(struct request_queue *q, char *page)
545 {
546         return queue_var_show(blk_queue_dax(q), page);
547 }
548
549 #define QUEUE_RO_ENTRY(_prefix, _name)                  \
550 static struct queue_sysfs_entry _prefix##_entry = {     \
551         .attr   = { .name = _name, .mode = 0444 },      \
552         .show   = _prefix##_show,                       \
553 };
554
555 #define QUEUE_RW_ENTRY(_prefix, _name)                  \
556 static struct queue_sysfs_entry _prefix##_entry = {     \
557         .attr   = { .name = _name, .mode = 0644 },      \
558         .show   = _prefix##_show,                       \
559         .store  = _prefix##_store,                      \
560 };
561
562 QUEUE_RW_ENTRY(queue_requests, "nr_requests");
563 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");
564 QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
565 QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
566 QUEUE_RO_ENTRY(queue_max_segments, "max_segments");
567 QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");
568 QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size");
569 QUEUE_RW_ENTRY(elv_iosched, "scheduler");
570
571 QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size");
572 QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size");
573 QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors");
574 QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size");
575 QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size");
576
577 QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments");
578 QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity");
579 QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes");
580 QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes");
581 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data");
582
583 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes");
584 QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes");
585 QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes");
586 QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity");
587
588 QUEUE_RO_ENTRY(queue_zoned, "zoned");
589 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones");
590 QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones");
591 QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones");
592
593 QUEUE_RW_ENTRY(queue_nomerges, "nomerges");
594 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity");
595 QUEUE_RW_ENTRY(queue_poll, "io_poll");
596 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay");
597 QUEUE_RW_ENTRY(queue_wc, "write_cache");
598 QUEUE_RO_ENTRY(queue_fua, "fua");
599 QUEUE_RO_ENTRY(queue_dax, "dax");
600 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
601 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec");
602 QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
603 QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment");
604
605 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
606 QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time");
607 #endif
608
609 /* legacy alias for logical_block_size: */
610 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
611         .attr = {.name = "hw_sector_size", .mode = 0444 },
612         .show = queue_logical_block_size_show,
613 };
614
615 QUEUE_RW_ENTRY(queue_nonrot, "rotational");
616 QUEUE_RW_ENTRY(queue_iostats, "iostats");
617 QUEUE_RW_ENTRY(queue_random, "add_random");
618 QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
619
620 static struct attribute *queue_attrs[] = {
621         &queue_requests_entry.attr,
622         &queue_ra_entry.attr,
623         &queue_max_hw_sectors_entry.attr,
624         &queue_max_sectors_entry.attr,
625         &queue_max_segments_entry.attr,
626         &queue_max_discard_segments_entry.attr,
627         &queue_max_integrity_segments_entry.attr,
628         &queue_max_segment_size_entry.attr,
629         &elv_iosched_entry.attr,
630         &queue_hw_sector_size_entry.attr,
631         &queue_logical_block_size_entry.attr,
632         &queue_physical_block_size_entry.attr,
633         &queue_chunk_sectors_entry.attr,
634         &queue_io_min_entry.attr,
635         &queue_io_opt_entry.attr,
636         &queue_discard_granularity_entry.attr,
637         &queue_discard_max_entry.attr,
638         &queue_discard_max_hw_entry.attr,
639         &queue_discard_zeroes_data_entry.attr,
640         &queue_write_same_max_entry.attr,
641         &queue_write_zeroes_max_entry.attr,
642         &queue_zone_append_max_entry.attr,
643         &queue_zone_write_granularity_entry.attr,
644         &queue_nonrot_entry.attr,
645         &queue_zoned_entry.attr,
646         &queue_nr_zones_entry.attr,
647         &queue_max_open_zones_entry.attr,
648         &queue_max_active_zones_entry.attr,
649         &queue_nomerges_entry.attr,
650         &queue_rq_affinity_entry.attr,
651         &queue_iostats_entry.attr,
652         &queue_stable_writes_entry.attr,
653         &queue_random_entry.attr,
654         &queue_poll_entry.attr,
655         &queue_wc_entry.attr,
656         &queue_fua_entry.attr,
657         &queue_dax_entry.attr,
658         &queue_wb_lat_entry.attr,
659         &queue_poll_delay_entry.attr,
660         &queue_io_timeout_entry.attr,
661 #ifdef CONFIG_BLK_DEV_THROTTLING_LOW
662         &blk_throtl_sample_time_entry.attr,
663 #endif
664         &queue_virt_boundary_mask_entry.attr,
665         &queue_dma_alignment_entry.attr,
666         NULL,
667 };
668
669 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
670                                 int n)
671 {
672         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
673         struct request_queue *q = disk->queue;
674
675         if (attr == &queue_io_timeout_entry.attr &&
676                 (!q->mq_ops || !q->mq_ops->timeout))
677                         return 0;
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
687 static struct attribute_group queue_attr_group = {
688         .attrs = queue_attrs,
689         .is_visible = queue_attr_visible,
690 };
691
692
693 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
694
695 static ssize_t
696 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
697 {
698         struct queue_sysfs_entry *entry = to_queue(attr);
699         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
700         struct request_queue *q = disk->queue;
701         ssize_t res;
702
703         if (!entry->show)
704                 return -EIO;
705         mutex_lock(&q->sysfs_lock);
706         res = entry->show(q, page);
707         mutex_unlock(&q->sysfs_lock);
708         return res;
709 }
710
711 static ssize_t
712 queue_attr_store(struct kobject *kobj, struct attribute *attr,
713                     const char *page, size_t length)
714 {
715         struct queue_sysfs_entry *entry = to_queue(attr);
716         struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
717         struct request_queue *q = disk->queue;
718         ssize_t res;
719
720         if (!entry->store)
721                 return -EIO;
722
723         mutex_lock(&q->sysfs_lock);
724         res = entry->store(q, page, length);
725         mutex_unlock(&q->sysfs_lock);
726         return res;
727 }
728
729 static const struct sysfs_ops queue_sysfs_ops = {
730         .show   = queue_attr_show,
731         .store  = queue_attr_store,
732 };
733
734 static const struct attribute_group *blk_queue_attr_groups[] = {
735         &queue_attr_group,
736         NULL
737 };
738
739 static void blk_queue_release(struct kobject *kobj)
740 {
741         /* nothing to do here, all data is associated with the parent gendisk */
742 }
743
744 static const struct kobj_type blk_queue_ktype = {
745         .default_groups = blk_queue_attr_groups,
746         .sysfs_ops      = &queue_sysfs_ops,
747         .release        = blk_queue_release,
748 };
749
750 static void blk_debugfs_remove(struct gendisk *disk)
751 {
752         struct request_queue *q = disk->queue;
753
754         mutex_lock(&q->debugfs_mutex);
755         blk_trace_shutdown(q);
756         debugfs_remove_recursive(q->debugfs_dir);
757         q->debugfs_dir = NULL;
758         q->sched_debugfs_dir = NULL;
759         q->rqos_debugfs_dir = NULL;
760         mutex_unlock(&q->debugfs_mutex);
761 }
762
763 /**
764  * blk_register_queue - register a block layer queue with sysfs
765  * @disk: Disk of which the request queue should be registered with sysfs.
766  */
767 int blk_register_queue(struct gendisk *disk)
768 {
769         struct request_queue *q = disk->queue;
770         int ret;
771
772         mutex_lock(&q->sysfs_dir_lock);
773         kobject_init(&disk->queue_kobj, &blk_queue_ktype);
774         ret = kobject_add(&disk->queue_kobj, &disk_to_dev(disk)->kobj, "queue");
775         if (ret < 0)
776                 goto out_put_queue_kobj;
777
778         if (queue_is_mq(q)) {
779                 ret = blk_mq_sysfs_register(disk);
780                 if (ret)
781                         goto out_put_queue_kobj;
782         }
783         mutex_lock(&q->sysfs_lock);
784
785         mutex_lock(&q->debugfs_mutex);
786         q->debugfs_dir = debugfs_create_dir(disk->disk_name, blk_debugfs_root);
787         if (queue_is_mq(q))
788                 blk_mq_debugfs_register(q);
789         mutex_unlock(&q->debugfs_mutex);
790
791         ret = disk_register_independent_access_ranges(disk);
792         if (ret)
793                 goto out_debugfs_remove;
794
795         if (q->elevator) {
796                 ret = elv_register_queue(q, false);
797                 if (ret)
798                         goto out_unregister_ia_ranges;
799         }
800
801         ret = blk_crypto_sysfs_register(disk);
802         if (ret)
803                 goto out_elv_unregister;
804
805         blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
806         wbt_enable_default(disk);
807         blk_throtl_register(disk);
808
809         /* Now everything is ready and send out KOBJ_ADD uevent */
810         kobject_uevent(&disk->queue_kobj, KOBJ_ADD);
811         if (q->elevator)
812                 kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
813         mutex_unlock(&q->sysfs_lock);
814         mutex_unlock(&q->sysfs_dir_lock);
815
816         /*
817          * SCSI probing may synchronously create and destroy a lot of
818          * request_queues for non-existent devices.  Shutting down a fully
819          * functional queue takes measureable wallclock time as RCU grace
820          * periods are involved.  To avoid excessive latency in these
821          * cases, a request_queue starts out in a degraded mode which is
822          * faster to shut down and is made fully functional here as
823          * request_queues for non-existent devices never get registered.
824          */
825         if (!blk_queue_init_done(q)) {
826                 blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
827                 percpu_ref_switch_to_percpu(&q->q_usage_counter);
828         }
829
830         return ret;
831
832 out_elv_unregister:
833         elv_unregister_queue(q);
834 out_unregister_ia_ranges:
835         disk_unregister_independent_access_ranges(disk);
836 out_debugfs_remove:
837         blk_debugfs_remove(disk);
838         mutex_unlock(&q->sysfs_lock);
839 out_put_queue_kobj:
840         kobject_put(&disk->queue_kobj);
841         mutex_unlock(&q->sysfs_dir_lock);
842         return ret;
843 }
844
845 /**
846  * blk_unregister_queue - counterpart of blk_register_queue()
847  * @disk: Disk of which the request queue should be unregistered from sysfs.
848  *
849  * Note: the caller is responsible for guaranteeing that this function is called
850  * after blk_register_queue() has finished.
851  */
852 void blk_unregister_queue(struct gendisk *disk)
853 {
854         struct request_queue *q = disk->queue;
855
856         if (WARN_ON(!q))
857                 return;
858
859         /* Return early if disk->queue was never registered. */
860         if (!blk_queue_registered(q))
861                 return;
862
863         /*
864          * Since sysfs_remove_dir() prevents adding new directory entries
865          * before removal of existing entries starts, protect against
866          * concurrent elv_iosched_store() calls.
867          */
868         mutex_lock(&q->sysfs_lock);
869         blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
870         mutex_unlock(&q->sysfs_lock);
871
872         mutex_lock(&q->sysfs_dir_lock);
873         /*
874          * Remove the sysfs attributes before unregistering the queue data
875          * structures that can be modified through sysfs.
876          */
877         if (queue_is_mq(q))
878                 blk_mq_sysfs_unregister(disk);
879         blk_crypto_sysfs_unregister(disk);
880
881         mutex_lock(&q->sysfs_lock);
882         elv_unregister_queue(q);
883         disk_unregister_independent_access_ranges(disk);
884         mutex_unlock(&q->sysfs_lock);
885
886         /* Now that we've deleted all child objects, we can delete the queue. */
887         kobject_uevent(&disk->queue_kobj, KOBJ_REMOVE);
888         kobject_del(&disk->queue_kobj);
889         mutex_unlock(&q->sysfs_dir_lock);
890
891         blk_debugfs_remove(disk);
892 }