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TOMOYO Linux Cross Reference
Linux/block/blk-sysfs.c

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

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