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/backing-dev.h>
10 #include <linux/blktrace_api.h>
11 #include <linux/blk-mq.h>
12 #include <linux/blk-cgroup.h>
13
14 #include "blk.h"
15 #include "blk-mq.h"
16
17 struct queue_sysfs_entry {
18 struct attribute attr;
19 ssize_t (*show)(struct request_queue *, char *);
20 ssize_t (*store)(struct request_queue *, const char *, size_t);
21 };
22
23 static ssize_t
queue_var_show(unsigned long var,char * page)24 queue_var_show(unsigned long var, char *page)
25 {
26 return sprintf(page, "%lu\n", var);
27 }
28
29 static ssize_t
queue_var_store(unsigned long * var,const char * page,size_t count)30 queue_var_store(unsigned long *var, const char *page, size_t count)
31 {
32 int err;
33 unsigned long v;
34
35 err = kstrtoul(page, 10, &v);
36 if (err || v > UINT_MAX)
37 return -EINVAL;
38
39 *var = v;
40
41 return count;
42 }
43
queue_requests_show(struct request_queue * q,char * page)44 static ssize_t queue_requests_show(struct request_queue *q, char *page)
45 {
46 return queue_var_show(q->nr_requests, (page));
47 }
48
49 static ssize_t
queue_requests_store(struct request_queue * q,const char * page,size_t count)50 queue_requests_store(struct request_queue *q, const char *page, size_t count)
51 {
52 unsigned long nr;
53 int ret, err;
54
55 if (!q->request_fn && !q->mq_ops)
56 return -EINVAL;
57
58 ret = queue_var_store(&nr, page, count);
59 if (ret < 0)
60 return ret;
61
62 if (nr < BLKDEV_MIN_RQ)
63 nr = BLKDEV_MIN_RQ;
64
65 if (q->request_fn)
66 err = blk_update_nr_requests(q, nr);
67 else
68 err = blk_mq_update_nr_requests(q, nr);
69
70 if (err)
71 return err;
72
73 return ret;
74 }
75
queue_ra_show(struct request_queue * q,char * page)76 static ssize_t queue_ra_show(struct request_queue *q, char *page)
77 {
78 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
79 (PAGE_CACHE_SHIFT - 10);
80
81 return queue_var_show(ra_kb, (page));
82 }
83
84 static ssize_t
queue_ra_store(struct request_queue * q,const char * page,size_t count)85 queue_ra_store(struct request_queue *q, const char *page, size_t count)
86 {
87 unsigned long ra_kb;
88 ssize_t ret = queue_var_store(&ra_kb, page, count);
89
90 if (ret < 0)
91 return ret;
92
93 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
94
95 return ret;
96 }
97
queue_max_sectors_show(struct request_queue * q,char * page)98 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
99 {
100 int max_sectors_kb = queue_max_sectors(q) >> 1;
101
102 return queue_var_show(max_sectors_kb, (page));
103 }
104
queue_max_segments_show(struct request_queue * q,char * page)105 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
106 {
107 return queue_var_show(queue_max_segments(q), (page));
108 }
109
queue_max_integrity_segments_show(struct request_queue * q,char * page)110 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
111 {
112 return queue_var_show(q->limits.max_integrity_segments, (page));
113 }
114
queue_max_segment_size_show(struct request_queue * q,char * page)115 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
116 {
117 if (blk_queue_cluster(q))
118 return queue_var_show(queue_max_segment_size(q), (page));
119
120 return queue_var_show(PAGE_CACHE_SIZE, (page));
121 }
122
queue_logical_block_size_show(struct request_queue * q,char * page)123 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
124 {
125 return queue_var_show(queue_logical_block_size(q), page);
126 }
127
queue_physical_block_size_show(struct request_queue * q,char * page)128 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
129 {
130 return queue_var_show(queue_physical_block_size(q), page);
131 }
132
queue_io_min_show(struct request_queue * q,char * page)133 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
134 {
135 return queue_var_show(queue_io_min(q), page);
136 }
137
queue_io_opt_show(struct request_queue * q,char * page)138 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
139 {
140 return queue_var_show(queue_io_opt(q), page);
141 }
142
queue_discard_granularity_show(struct request_queue * q,char * page)143 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
144 {
145 return queue_var_show(q->limits.discard_granularity, page);
146 }
147
queue_discard_max_hw_show(struct request_queue * q,char * page)148 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
149 {
150 unsigned long long val;
151
152 val = q->limits.max_hw_discard_sectors << 9;
153 return sprintf(page, "%llu\n", val);
154 }
155
queue_discard_max_show(struct request_queue * q,char * page)156 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
157 {
158 return sprintf(page, "%llu\n",
159 (unsigned long long)q->limits.max_discard_sectors << 9);
160 }
161
queue_discard_max_store(struct request_queue * q,const char * page,size_t count)162 static ssize_t queue_discard_max_store(struct request_queue *q,
163 const char *page, size_t count)
164 {
165 unsigned long max_discard;
166 ssize_t ret = queue_var_store(&max_discard, page, count);
167
168 if (ret < 0)
169 return ret;
170
171 if (max_discard & (q->limits.discard_granularity - 1))
172 return -EINVAL;
173
174 max_discard >>= 9;
175 if (max_discard > UINT_MAX)
176 return -EINVAL;
177
178 if (max_discard > q->limits.max_hw_discard_sectors)
179 max_discard = q->limits.max_hw_discard_sectors;
180
181 q->limits.max_discard_sectors = max_discard;
182 return ret;
183 }
184
queue_discard_zeroes_data_show(struct request_queue * q,char * page)185 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
186 {
187 return queue_var_show(queue_discard_zeroes_data(q), page);
188 }
189
queue_write_same_max_show(struct request_queue * q,char * page)190 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
191 {
192 return sprintf(page, "%llu\n",
193 (unsigned long long)q->limits.max_write_same_sectors << 9);
194 }
195
196
197 static ssize_t
queue_max_sectors_store(struct request_queue * q,const char * page,size_t count)198 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
199 {
200 unsigned long max_sectors_kb,
201 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
202 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
203 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
204
205 if (ret < 0)
206 return ret;
207
208 max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
209 q->limits.max_dev_sectors >> 1);
210
211 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
212 return -EINVAL;
213
214 spin_lock_irq(q->queue_lock);
215 q->limits.max_sectors = max_sectors_kb << 1;
216 spin_unlock_irq(q->queue_lock);
217
218 return ret;
219 }
220
queue_max_hw_sectors_show(struct request_queue * q,char * page)221 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
222 {
223 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
224
225 return queue_var_show(max_hw_sectors_kb, (page));
226 }
227
228 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
229 static ssize_t \
230 queue_show_##name(struct request_queue *q, char *page) \
231 { \
232 int bit; \
233 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
234 return queue_var_show(neg ? !bit : bit, page); \
235 } \
236 static ssize_t \
237 queue_store_##name(struct request_queue *q, const char *page, size_t count) \
238 { \
239 unsigned long val; \
240 ssize_t ret; \
241 ret = queue_var_store(&val, page, count); \
242 if (ret < 0) \
243 return ret; \
244 if (neg) \
245 val = !val; \
246 \
247 spin_lock_irq(q->queue_lock); \
248 if (val) \
249 queue_flag_set(QUEUE_FLAG_##flag, q); \
250 else \
251 queue_flag_clear(QUEUE_FLAG_##flag, q); \
252 spin_unlock_irq(q->queue_lock); \
253 return ret; \
254 }
255
256 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
257 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
258 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
259 #undef QUEUE_SYSFS_BIT_FNS
260
queue_nomerges_show(struct request_queue * q,char * page)261 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
262 {
263 return queue_var_show((blk_queue_nomerges(q) << 1) |
264 blk_queue_noxmerges(q), page);
265 }
266
queue_nomerges_store(struct request_queue * q,const char * page,size_t count)267 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
268 size_t count)
269 {
270 unsigned long nm;
271 ssize_t ret = queue_var_store(&nm, page, count);
272
273 if (ret < 0)
274 return ret;
275
276 spin_lock_irq(q->queue_lock);
277 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
278 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
279 if (nm == 2)
280 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
281 else if (nm)
282 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
283 spin_unlock_irq(q->queue_lock);
284
285 return ret;
286 }
287
queue_rq_affinity_show(struct request_queue * q,char * page)288 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
289 {
290 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
291 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
292
293 return queue_var_show(set << force, page);
294 }
295
296 static ssize_t
queue_rq_affinity_store(struct request_queue * q,const char * page,size_t count)297 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
298 {
299 ssize_t ret = -EINVAL;
300 #ifdef CONFIG_SMP
301 unsigned long val;
302
303 ret = queue_var_store(&val, page, count);
304 if (ret < 0)
305 return ret;
306
307 spin_lock_irq(q->queue_lock);
308 if (val == 2) {
309 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
310 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
311 } else if (val == 1) {
312 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
313 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
314 } else if (val == 0) {
315 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
316 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
317 }
318 spin_unlock_irq(q->queue_lock);
319 #endif
320 return ret;
321 }
322
queue_poll_show(struct request_queue * q,char * page)323 static ssize_t queue_poll_show(struct request_queue *q, char *page)
324 {
325 return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
326 }
327
queue_poll_store(struct request_queue * q,const char * page,size_t count)328 static ssize_t queue_poll_store(struct request_queue *q, const char *page,
329 size_t count)
330 {
331 unsigned long poll_on;
332 ssize_t ret;
333
334 if (!q->mq_ops || !q->mq_ops->poll)
335 return -EINVAL;
336
337 ret = queue_var_store(&poll_on, page, count);
338 if (ret < 0)
339 return ret;
340
341 spin_lock_irq(q->queue_lock);
342 if (poll_on)
343 queue_flag_set(QUEUE_FLAG_POLL, q);
344 else
345 queue_flag_clear(QUEUE_FLAG_POLL, q);
346 spin_unlock_irq(q->queue_lock);
347
348 return ret;
349 }
350
351 static struct queue_sysfs_entry queue_requests_entry = {
352 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
353 .show = queue_requests_show,
354 .store = queue_requests_store,
355 };
356
357 static struct queue_sysfs_entry queue_ra_entry = {
358 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
359 .show = queue_ra_show,
360 .store = queue_ra_store,
361 };
362
363 static struct queue_sysfs_entry queue_max_sectors_entry = {
364 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
365 .show = queue_max_sectors_show,
366 .store = queue_max_sectors_store,
367 };
368
369 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
370 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
371 .show = queue_max_hw_sectors_show,
372 };
373
374 static struct queue_sysfs_entry queue_max_segments_entry = {
375 .attr = {.name = "max_segments", .mode = S_IRUGO },
376 .show = queue_max_segments_show,
377 };
378
379 static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
380 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
381 .show = queue_max_integrity_segments_show,
382 };
383
384 static struct queue_sysfs_entry queue_max_segment_size_entry = {
385 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
386 .show = queue_max_segment_size_show,
387 };
388
389 static struct queue_sysfs_entry queue_iosched_entry = {
390 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
391 .show = elv_iosched_show,
392 .store = elv_iosched_store,
393 };
394
395 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
396 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
397 .show = queue_logical_block_size_show,
398 };
399
400 static struct queue_sysfs_entry queue_logical_block_size_entry = {
401 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
402 .show = queue_logical_block_size_show,
403 };
404
405 static struct queue_sysfs_entry queue_physical_block_size_entry = {
406 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
407 .show = queue_physical_block_size_show,
408 };
409
410 static struct queue_sysfs_entry queue_io_min_entry = {
411 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
412 .show = queue_io_min_show,
413 };
414
415 static struct queue_sysfs_entry queue_io_opt_entry = {
416 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
417 .show = queue_io_opt_show,
418 };
419
420 static struct queue_sysfs_entry queue_discard_granularity_entry = {
421 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
422 .show = queue_discard_granularity_show,
423 };
424
425 static struct queue_sysfs_entry queue_discard_max_hw_entry = {
426 .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
427 .show = queue_discard_max_hw_show,
428 };
429
430 static struct queue_sysfs_entry queue_discard_max_entry = {
431 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
432 .show = queue_discard_max_show,
433 .store = queue_discard_max_store,
434 };
435
436 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
437 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
438 .show = queue_discard_zeroes_data_show,
439 };
440
441 static struct queue_sysfs_entry queue_write_same_max_entry = {
442 .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
443 .show = queue_write_same_max_show,
444 };
445
446 static struct queue_sysfs_entry queue_nonrot_entry = {
447 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
448 .show = queue_show_nonrot,
449 .store = queue_store_nonrot,
450 };
451
452 static struct queue_sysfs_entry queue_nomerges_entry = {
453 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
454 .show = queue_nomerges_show,
455 .store = queue_nomerges_store,
456 };
457
458 static struct queue_sysfs_entry queue_rq_affinity_entry = {
459 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
460 .show = queue_rq_affinity_show,
461 .store = queue_rq_affinity_store,
462 };
463
464 static struct queue_sysfs_entry queue_iostats_entry = {
465 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
466 .show = queue_show_iostats,
467 .store = queue_store_iostats,
468 };
469
470 static struct queue_sysfs_entry queue_random_entry = {
471 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
472 .show = queue_show_random,
473 .store = queue_store_random,
474 };
475
476 static struct queue_sysfs_entry queue_poll_entry = {
477 .attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR },
478 .show = queue_poll_show,
479 .store = queue_poll_store,
480 };
481
482 static struct attribute *default_attrs[] = {
483 &queue_requests_entry.attr,
484 &queue_ra_entry.attr,
485 &queue_max_hw_sectors_entry.attr,
486 &queue_max_sectors_entry.attr,
487 &queue_max_segments_entry.attr,
488 &queue_max_integrity_segments_entry.attr,
489 &queue_max_segment_size_entry.attr,
490 &queue_iosched_entry.attr,
491 &queue_hw_sector_size_entry.attr,
492 &queue_logical_block_size_entry.attr,
493 &queue_physical_block_size_entry.attr,
494 &queue_io_min_entry.attr,
495 &queue_io_opt_entry.attr,
496 &queue_discard_granularity_entry.attr,
497 &queue_discard_max_entry.attr,
498 &queue_discard_max_hw_entry.attr,
499 &queue_discard_zeroes_data_entry.attr,
500 &queue_write_same_max_entry.attr,
501 &queue_nonrot_entry.attr,
502 &queue_nomerges_entry.attr,
503 &queue_rq_affinity_entry.attr,
504 &queue_iostats_entry.attr,
505 &queue_random_entry.attr,
506 &queue_poll_entry.attr,
507 NULL,
508 };
509
510 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
511
512 static ssize_t
queue_attr_show(struct kobject * kobj,struct attribute * attr,char * page)513 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
514 {
515 struct queue_sysfs_entry *entry = to_queue(attr);
516 struct request_queue *q =
517 container_of(kobj, struct request_queue, kobj);
518 ssize_t res;
519
520 if (!entry->show)
521 return -EIO;
522 mutex_lock(&q->sysfs_lock);
523 if (blk_queue_dying(q)) {
524 mutex_unlock(&q->sysfs_lock);
525 return -ENOENT;
526 }
527 res = entry->show(q, page);
528 mutex_unlock(&q->sysfs_lock);
529 return res;
530 }
531
532 static ssize_t
queue_attr_store(struct kobject * kobj,struct attribute * attr,const char * page,size_t length)533 queue_attr_store(struct kobject *kobj, struct attribute *attr,
534 const char *page, size_t length)
535 {
536 struct queue_sysfs_entry *entry = to_queue(attr);
537 struct request_queue *q;
538 ssize_t res;
539
540 if (!entry->store)
541 return -EIO;
542
543 q = container_of(kobj, struct request_queue, kobj);
544 mutex_lock(&q->sysfs_lock);
545 if (blk_queue_dying(q)) {
546 mutex_unlock(&q->sysfs_lock);
547 return -ENOENT;
548 }
549 res = entry->store(q, page, length);
550 mutex_unlock(&q->sysfs_lock);
551 return res;
552 }
553
blk_free_queue_rcu(struct rcu_head * rcu_head)554 static void blk_free_queue_rcu(struct rcu_head *rcu_head)
555 {
556 struct request_queue *q = container_of(rcu_head, struct request_queue,
557 rcu_head);
558 kmem_cache_free(blk_requestq_cachep, q);
559 }
560
561 /**
562 * blk_release_queue: - release a &struct request_queue when it is no longer needed
563 * @kobj: the kobj belonging to the request queue to be released
564 *
565 * Description:
566 * blk_release_queue is the pair to blk_init_queue() or
567 * blk_queue_make_request(). It should be called when a request queue is
568 * being released; typically when a block device is being de-registered.
569 * Currently, its primary task it to free all the &struct request
570 * structures that were allocated to the queue and the queue itself.
571 *
572 * Note:
573 * The low level driver must have finished any outstanding requests first
574 * via blk_cleanup_queue().
575 **/
blk_release_queue(struct kobject * kobj)576 static void blk_release_queue(struct kobject *kobj)
577 {
578 struct request_queue *q =
579 container_of(kobj, struct request_queue, kobj);
580
581 bdi_exit(&q->backing_dev_info);
582 blkcg_exit_queue(q);
583
584 if (q->elevator) {
585 spin_lock_irq(q->queue_lock);
586 ioc_clear_queue(q);
587 spin_unlock_irq(q->queue_lock);
588 elevator_exit(q->elevator);
589 }
590
591 blk_exit_rl(&q->root_rl);
592
593 if (q->queue_tags)
594 __blk_queue_free_tags(q);
595
596 if (!q->mq_ops)
597 blk_free_flush_queue(q->fq);
598 else
599 blk_mq_release(q);
600
601 blk_trace_shutdown(q);
602
603 if (q->bio_split)
604 bioset_free(q->bio_split);
605
606 ida_simple_remove(&blk_queue_ida, q->id);
607 call_rcu(&q->rcu_head, blk_free_queue_rcu);
608 }
609
610 static const struct sysfs_ops queue_sysfs_ops = {
611 .show = queue_attr_show,
612 .store = queue_attr_store,
613 };
614
615 struct kobj_type blk_queue_ktype = {
616 .sysfs_ops = &queue_sysfs_ops,
617 .default_attrs = default_attrs,
618 .release = blk_release_queue,
619 };
620
blk_register_queue(struct gendisk * disk)621 int blk_register_queue(struct gendisk *disk)
622 {
623 int ret;
624 struct device *dev = disk_to_dev(disk);
625 struct request_queue *q = disk->queue;
626
627 if (WARN_ON(!q))
628 return -ENXIO;
629
630 /*
631 * SCSI probing may synchronously create and destroy a lot of
632 * request_queues for non-existent devices. Shutting down a fully
633 * functional queue takes measureable wallclock time as RCU grace
634 * periods are involved. To avoid excessive latency in these
635 * cases, a request_queue starts out in a degraded mode which is
636 * faster to shut down and is made fully functional here as
637 * request_queues for non-existent devices never get registered.
638 */
639 if (!blk_queue_init_done(q)) {
640 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
641 percpu_ref_switch_to_percpu(&q->q_usage_counter);
642 blk_queue_bypass_end(q);
643 }
644
645 ret = blk_trace_init_sysfs(dev);
646 if (ret)
647 return ret;
648
649 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
650 if (ret < 0) {
651 blk_trace_remove_sysfs(dev);
652 return ret;
653 }
654
655 kobject_uevent(&q->kobj, KOBJ_ADD);
656
657 if (q->mq_ops)
658 blk_mq_register_disk(disk);
659
660 if (!q->request_fn)
661 return 0;
662
663 ret = elv_register_queue(q);
664 if (ret) {
665 kobject_uevent(&q->kobj, KOBJ_REMOVE);
666 kobject_del(&q->kobj);
667 blk_trace_remove_sysfs(dev);
668 kobject_put(&dev->kobj);
669 return ret;
670 }
671
672 return 0;
673 }
674
blk_unregister_queue(struct gendisk * disk)675 void blk_unregister_queue(struct gendisk *disk)
676 {
677 struct request_queue *q = disk->queue;
678
679 if (WARN_ON(!q))
680 return;
681
682 if (q->mq_ops)
683 blk_mq_unregister_disk(disk);
684
685 if (q->request_fn)
686 elv_unregister_queue(q);
687
688 kobject_uevent(&q->kobj, KOBJ_REMOVE);
689 kobject_del(&q->kobj);
690 blk_trace_remove_sysfs(disk_to_dev(disk));
691 kobject_put(&disk_to_dev(disk)->kobj);
692 }
693