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1/*
2 * Functions related to sysfs handling
3 */
4#include <linux/kernel.h>
5a0e3ad6 5#include <linux/slab.h>
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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
13struct queue_sysfs_entry {
14 struct attribute attr;
15 ssize_t (*show)(struct request_queue *, char *);
16 ssize_t (*store)(struct request_queue *, const char *, size_t);
17};
18
19static ssize_t
9cb308ce 20queue_var_show(unsigned long var, char *page)
8324aa91 21{
9cb308ce 22 return sprintf(page, "%lu\n", var);
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23}
24
25static ssize_t
26queue_var_store(unsigned long *var, const char *page, size_t count)
27{
28 char *p = (char *) page;
29
30 *var = simple_strtoul(p, &p, 10);
31 return count;
32}
33
34static ssize_t queue_requests_show(struct request_queue *q, char *page)
35{
36 return queue_var_show(q->nr_requests, (page));
37}
38
39static ssize_t
40queue_requests_store(struct request_queue *q, const char *page, size_t count)
41{
42 struct request_list *rl = &q->rq;
43 unsigned long nr;
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44 int ret;
45
46 if (!q->request_fn)
47 return -EINVAL;
48
49 ret = queue_var_store(&nr, page, count);
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50 if (nr < BLKDEV_MIN_RQ)
51 nr = BLKDEV_MIN_RQ;
52
53 spin_lock_irq(q->queue_lock);
54 q->nr_requests = nr;
55 blk_queue_congestion_threshold(q);
56
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57 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
58 blk_set_queue_congested(q, BLK_RW_SYNC);
59 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
60 blk_clear_queue_congested(q, BLK_RW_SYNC);
61
62 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
63 blk_set_queue_congested(q, BLK_RW_ASYNC);
64 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
65 blk_clear_queue_congested(q, BLK_RW_ASYNC);
66
67 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
68 blk_set_queue_full(q, BLK_RW_SYNC);
69 } else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
70 blk_clear_queue_full(q, BLK_RW_SYNC);
71 wake_up(&rl->wait[BLK_RW_SYNC]);
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72 }
73
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74 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
75 blk_set_queue_full(q, BLK_RW_ASYNC);
76 } else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
77 blk_clear_queue_full(q, BLK_RW_ASYNC);
78 wake_up(&rl->wait[BLK_RW_ASYNC]);
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79 }
80 spin_unlock_irq(q->queue_lock);
81 return ret;
82}
83
84static ssize_t queue_ra_show(struct request_queue *q, char *page)
85{
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86 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
87 (PAGE_CACHE_SHIFT - 10);
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88
89 return queue_var_show(ra_kb, (page));
90}
91
92static ssize_t
93queue_ra_store(struct request_queue *q, const char *page, size_t count)
94{
95 unsigned long ra_kb;
96 ssize_t ret = queue_var_store(&ra_kb, page, count);
97
8324aa91 98 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
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99
100 return ret;
101}
102
103static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
104{
ae03bf63 105 int max_sectors_kb = queue_max_sectors(q) >> 1;
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106
107 return queue_var_show(max_sectors_kb, (page));
108}
109
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110static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
111{
112 return queue_var_show(queue_max_segments(q), (page));
113}
114
115static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
116{
117 if (test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags))
118 return queue_var_show(queue_max_segment_size(q), (page));
119
120 return queue_var_show(PAGE_CACHE_SIZE, (page));
121}
122
e1defc4f 123static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
e68b903c 124{
e1defc4f 125 return queue_var_show(queue_logical_block_size(q), page);
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126}
127
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128static 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
133static 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
138static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
139{
140 return queue_var_show(queue_io_opt(q), page);
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141}
142
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143static 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
148static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
149{
150 return queue_var_show(q->limits.max_discard_sectors << 9, page);
151}
152
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153static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
154{
155 return queue_var_show(queue_discard_zeroes_data(q), page);
156}
157
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158static ssize_t
159queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
160{
161 unsigned long max_sectors_kb,
ae03bf63 162 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
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163 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
164 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
165
166 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
167 return -EINVAL;
7c239517 168
8324aa91 169 spin_lock_irq(q->queue_lock);
c295fc05 170 q->limits.max_sectors = max_sectors_kb << 1;
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171 spin_unlock_irq(q->queue_lock);
172
173 return ret;
174}
175
176static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
177{
ae03bf63 178 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
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179
180 return queue_var_show(max_hw_sectors_kb, (page));
181}
182
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183static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
184{
185 return queue_var_show(!blk_queue_nonrot(q), page);
186}
187
188static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
189 size_t count)
190{
191 unsigned long nm;
192 ssize_t ret = queue_var_store(&nm, page, count);
193
194 spin_lock_irq(q->queue_lock);
195 if (nm)
196 queue_flag_clear(QUEUE_FLAG_NONROT, q);
197 else
198 queue_flag_set(QUEUE_FLAG_NONROT, q);
199 spin_unlock_irq(q->queue_lock);
200
201 return ret;
202}
203
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204static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
205{
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206 return queue_var_show((blk_queue_nomerges(q) << 1) |
207 blk_queue_noxmerges(q), page);
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208}
209
210static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
211 size_t count)
212{
213 unsigned long nm;
214 ssize_t ret = queue_var_store(&nm, page, count);
215
bf0f9702 216 spin_lock_irq(q->queue_lock);
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217 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
218 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
219 if (nm == 2)
bf0f9702 220 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
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221 else if (nm)
222 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
bf0f9702 223 spin_unlock_irq(q->queue_lock);
1308835f 224
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225 return ret;
226}
227
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228static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
229{
9cb308ce 230 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
c7c22e4d 231
9cb308ce 232 return queue_var_show(set, page);
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233}
234
235static ssize_t
236queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
237{
238 ssize_t ret = -EINVAL;
239#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
240 unsigned long val;
241
242 ret = queue_var_store(&val, page, count);
243 spin_lock_irq(q->queue_lock);
244 if (val)
245 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
246 else
247 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
248 spin_unlock_irq(q->queue_lock);
249#endif
250 return ret;
251}
8324aa91 252
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253static ssize_t queue_random_show(struct request_queue *q, char *page)
254{
255 return queue_var_show(blk_queue_add_random(q), page);
256}
257
258static ssize_t queue_random_store(struct request_queue *q, const char *page,
259 size_t count)
260{
261 unsigned long val;
262 ssize_t ret = queue_var_store(&val, page, count);
263
264 spin_lock_irq(q->queue_lock);
265 if (val)
266 queue_flag_set(QUEUE_FLAG_ADD_RANDOM, q);
267 else
268 queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
269 spin_unlock_irq(q->queue_lock);
270
271 return ret;
272}
273
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274static ssize_t queue_iostats_show(struct request_queue *q, char *page)
275{
276 return queue_var_show(blk_queue_io_stat(q), page);
277}
278
279static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
280 size_t count)
281{
282 unsigned long stats;
283 ssize_t ret = queue_var_store(&stats, page, count);
284
285 spin_lock_irq(q->queue_lock);
286 if (stats)
287 queue_flag_set(QUEUE_FLAG_IO_STAT, q);
288 else
289 queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
290 spin_unlock_irq(q->queue_lock);
291
292 return ret;
293}
294
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295static struct queue_sysfs_entry queue_requests_entry = {
296 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
297 .show = queue_requests_show,
298 .store = queue_requests_store,
299};
300
301static struct queue_sysfs_entry queue_ra_entry = {
302 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
303 .show = queue_ra_show,
304 .store = queue_ra_store,
305};
306
307static struct queue_sysfs_entry queue_max_sectors_entry = {
308 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
309 .show = queue_max_sectors_show,
310 .store = queue_max_sectors_store,
311};
312
313static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
314 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
315 .show = queue_max_hw_sectors_show,
316};
317
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318static struct queue_sysfs_entry queue_max_segments_entry = {
319 .attr = {.name = "max_segments", .mode = S_IRUGO },
320 .show = queue_max_segments_show,
321};
322
323static struct queue_sysfs_entry queue_max_segment_size_entry = {
324 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
325 .show = queue_max_segment_size_show,
326};
327
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328static struct queue_sysfs_entry queue_iosched_entry = {
329 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
330 .show = elv_iosched_show,
331 .store = elv_iosched_store,
332};
333
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334static struct queue_sysfs_entry queue_hw_sector_size_entry = {
335 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
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336 .show = queue_logical_block_size_show,
337};
338
339static struct queue_sysfs_entry queue_logical_block_size_entry = {
340 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
341 .show = queue_logical_block_size_show,
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342};
343
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344static struct queue_sysfs_entry queue_physical_block_size_entry = {
345 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
346 .show = queue_physical_block_size_show,
347};
348
349static struct queue_sysfs_entry queue_io_min_entry = {
350 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
351 .show = queue_io_min_show,
352};
353
354static struct queue_sysfs_entry queue_io_opt_entry = {
355 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
356 .show = queue_io_opt_show,
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357};
358
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359static struct queue_sysfs_entry queue_discard_granularity_entry = {
360 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
361 .show = queue_discard_granularity_show,
362};
363
364static struct queue_sysfs_entry queue_discard_max_entry = {
365 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
366 .show = queue_discard_max_show,
367};
368
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369static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
370 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
371 .show = queue_discard_zeroes_data_show,
372};
373
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374static struct queue_sysfs_entry queue_nonrot_entry = {
375 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
376 .show = queue_nonrot_show,
377 .store = queue_nonrot_store,
378};
379
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380static struct queue_sysfs_entry queue_nomerges_entry = {
381 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
382 .show = queue_nomerges_show,
383 .store = queue_nomerges_store,
384};
385
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386static struct queue_sysfs_entry queue_rq_affinity_entry = {
387 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
388 .show = queue_rq_affinity_show,
389 .store = queue_rq_affinity_store,
390};
391
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392static struct queue_sysfs_entry queue_iostats_entry = {
393 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
394 .show = queue_iostats_show,
395 .store = queue_iostats_store,
396};
397
e2e1a148
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398static struct queue_sysfs_entry queue_random_entry = {
399 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
400 .show = queue_random_show,
401 .store = queue_random_store,
402};
403
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404static struct attribute *default_attrs[] = {
405 &queue_requests_entry.attr,
406 &queue_ra_entry.attr,
407 &queue_max_hw_sectors_entry.attr,
408 &queue_max_sectors_entry.attr,
c77a5710
MP
409 &queue_max_segments_entry.attr,
410 &queue_max_segment_size_entry.attr,
8324aa91 411 &queue_iosched_entry.attr,
e68b903c 412 &queue_hw_sector_size_entry.attr,
e1defc4f 413 &queue_logical_block_size_entry.attr,
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414 &queue_physical_block_size_entry.attr,
415 &queue_io_min_entry.attr,
416 &queue_io_opt_entry.attr,
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417 &queue_discard_granularity_entry.attr,
418 &queue_discard_max_entry.attr,
98262f27 419 &queue_discard_zeroes_data_entry.attr,
1308835f 420 &queue_nonrot_entry.attr,
ac9fafa1 421 &queue_nomerges_entry.attr,
c7c22e4d 422 &queue_rq_affinity_entry.attr,
bc58ba94 423 &queue_iostats_entry.attr,
e2e1a148 424 &queue_random_entry.attr,
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425 NULL,
426};
427
428#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
429
430static ssize_t
431queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
432{
433 struct queue_sysfs_entry *entry = to_queue(attr);
434 struct request_queue *q =
435 container_of(kobj, struct request_queue, kobj);
436 ssize_t res;
437
438 if (!entry->show)
439 return -EIO;
440 mutex_lock(&q->sysfs_lock);
441 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
442 mutex_unlock(&q->sysfs_lock);
443 return -ENOENT;
444 }
445 res = entry->show(q, page);
446 mutex_unlock(&q->sysfs_lock);
447 return res;
448}
449
450static ssize_t
451queue_attr_store(struct kobject *kobj, struct attribute *attr,
452 const char *page, size_t length)
453{
454 struct queue_sysfs_entry *entry = to_queue(attr);
6728cb0e 455 struct request_queue *q;
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456 ssize_t res;
457
458 if (!entry->store)
459 return -EIO;
6728cb0e
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460
461 q = container_of(kobj, struct request_queue, kobj);
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462 mutex_lock(&q->sysfs_lock);
463 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
464 mutex_unlock(&q->sysfs_lock);
465 return -ENOENT;
466 }
467 res = entry->store(q, page, length);
468 mutex_unlock(&q->sysfs_lock);
469 return res;
470}
471
472/**
473 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
474 * @kobj: the kobj belonging of the request queue to be released
475 *
476 * Description:
477 * blk_cleanup_queue is the pair to blk_init_queue() or
478 * blk_queue_make_request(). It should be called when a request queue is
479 * being released; typically when a block device is being de-registered.
480 * Currently, its primary task it to free all the &struct request
481 * structures that were allocated to the queue and the queue itself.
482 *
483 * Caveat:
484 * Hopefully the low level driver will have finished any
485 * outstanding requests first...
486 **/
487static void blk_release_queue(struct kobject *kobj)
488{
489 struct request_queue *q =
490 container_of(kobj, struct request_queue, kobj);
491 struct request_list *rl = &q->rq;
492
493 blk_sync_queue(q);
494
495 if (rl->rq_pool)
496 mempool_destroy(rl->rq_pool);
497
498 if (q->queue_tags)
499 __blk_queue_free_tags(q);
500
501 blk_trace_shutdown(q);
502
503 bdi_destroy(&q->backing_dev_info);
504 kmem_cache_free(blk_requestq_cachep, q);
505}
506
52cf25d0 507static const struct sysfs_ops queue_sysfs_ops = {
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508 .show = queue_attr_show,
509 .store = queue_attr_store,
510};
511
512struct kobj_type blk_queue_ktype = {
513 .sysfs_ops = &queue_sysfs_ops,
514 .default_attrs = default_attrs,
515 .release = blk_release_queue,
516};
517
518int blk_register_queue(struct gendisk *disk)
519{
520 int ret;
1d54ad6d 521 struct device *dev = disk_to_dev(disk);
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522
523 struct request_queue *q = disk->queue;
524
fb199746 525 if (WARN_ON(!q))
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526 return -ENXIO;
527
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528 ret = blk_trace_init_sysfs(dev);
529 if (ret)
530 return ret;
531
c9059598 532 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
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533 if (ret < 0)
534 return ret;
535
536 kobject_uevent(&q->kobj, KOBJ_ADD);
537
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MP
538 if (!q->request_fn)
539 return 0;
540
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541 ret = elv_register_queue(q);
542 if (ret) {
543 kobject_uevent(&q->kobj, KOBJ_REMOVE);
544 kobject_del(&q->kobj);
48c0d4d4 545 blk_trace_remove_sysfs(disk_to_dev(disk));
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546 return ret;
547 }
548
549 return 0;
550}
551
552void blk_unregister_queue(struct gendisk *disk)
553{
554 struct request_queue *q = disk->queue;
555
fb199746
AM
556 if (WARN_ON(!q))
557 return;
558
48c0d4d4 559 if (q->request_fn)
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560 elv_unregister_queue(q);
561
48c0d4d4
ZK
562 kobject_uevent(&q->kobj, KOBJ_REMOVE);
563 kobject_del(&q->kobj);
564 blk_trace_remove_sysfs(disk_to_dev(disk));
565 kobject_put(&disk_to_dev(disk)->kobj);
8324aa91 566}