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