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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);
60735b63 69 } else {
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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);
60735b63 76 } else {
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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{
9cb308ce
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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
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115static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
116{
117 return queue_var_show(q->limits.max_integrity_segments, (page));
118}
119
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120static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
121{
e692cb66 122 if (blk_queue_cluster(q))
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123 return queue_var_show(queue_max_segment_size(q), (page));
124
125 return queue_var_show(PAGE_CACHE_SIZE, (page));
126}
127
e1defc4f 128static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
e68b903c 129{
e1defc4f 130 return queue_var_show(queue_logical_block_size(q), page);
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131}
132
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133static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
134{
135 return queue_var_show(queue_physical_block_size(q), page);
136}
137
138static ssize_t queue_io_min_show(struct request_queue *q, char *page)
139{
140 return queue_var_show(queue_io_min(q), page);
141}
142
143static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
144{
145 return queue_var_show(queue_io_opt(q), page);
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146}
147
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148static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
149{
150 return queue_var_show(q->limits.discard_granularity, page);
151}
152
153static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
154{
a934a00a
MP
155 return sprintf(page, "%llu\n",
156 (unsigned long long)q->limits.max_discard_sectors << 9);
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157}
158
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159static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
160{
161 return queue_var_show(queue_discard_zeroes_data(q), page);
162}
163
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164static ssize_t
165queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
166{
167 unsigned long max_sectors_kb,
ae03bf63 168 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
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169 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
170 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
171
172 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
173 return -EINVAL;
7c239517 174
8324aa91 175 spin_lock_irq(q->queue_lock);
c295fc05 176 q->limits.max_sectors = max_sectors_kb << 1;
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177 spin_unlock_irq(q->queue_lock);
178
179 return ret;
180}
181
182static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
183{
ae03bf63 184 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
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185
186 return queue_var_show(max_hw_sectors_kb, (page));
187}
188
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189#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
190static ssize_t \
191queue_show_##name(struct request_queue *q, char *page) \
192{ \
193 int bit; \
194 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
195 return queue_var_show(neg ? !bit : bit, page); \
196} \
197static ssize_t \
198queue_store_##name(struct request_queue *q, const char *page, size_t count) \
199{ \
200 unsigned long val; \
201 ssize_t ret; \
202 ret = queue_var_store(&val, page, count); \
203 if (neg) \
204 val = !val; \
205 \
206 spin_lock_irq(q->queue_lock); \
207 if (val) \
208 queue_flag_set(QUEUE_FLAG_##flag, q); \
209 else \
210 queue_flag_clear(QUEUE_FLAG_##flag, q); \
211 spin_unlock_irq(q->queue_lock); \
212 return ret; \
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213}
214
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215QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
216QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
217QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
218#undef QUEUE_SYSFS_BIT_FNS
1308835f 219
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220static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
221{
488991e2
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222 return queue_var_show((blk_queue_nomerges(q) << 1) |
223 blk_queue_noxmerges(q), page);
ac9fafa1
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224}
225
226static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
227 size_t count)
228{
229 unsigned long nm;
230 ssize_t ret = queue_var_store(&nm, page, count);
231
bf0f9702 232 spin_lock_irq(q->queue_lock);
488991e2
AB
233 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
234 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
235 if (nm == 2)
bf0f9702 236 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
488991e2
AB
237 else if (nm)
238 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
bf0f9702 239 spin_unlock_irq(q->queue_lock);
1308835f 240
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AB
241 return ret;
242}
243
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244static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
245{
9cb308ce 246 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
c7c22e4d 247
9cb308ce 248 return queue_var_show(set, page);
c7c22e4d
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249}
250
251static ssize_t
252queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
253{
254 ssize_t ret = -EINVAL;
255#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
256 unsigned long val;
257
258 ret = queue_var_store(&val, page, count);
259 spin_lock_irq(q->queue_lock);
260 if (val)
261 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
262 else
263 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
264 spin_unlock_irq(q->queue_lock);
265#endif
266 return ret;
267}
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268
269static struct queue_sysfs_entry queue_requests_entry = {
270 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
271 .show = queue_requests_show,
272 .store = queue_requests_store,
273};
274
275static struct queue_sysfs_entry queue_ra_entry = {
276 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
277 .show = queue_ra_show,
278 .store = queue_ra_store,
279};
280
281static struct queue_sysfs_entry queue_max_sectors_entry = {
282 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
283 .show = queue_max_sectors_show,
284 .store = queue_max_sectors_store,
285};
286
287static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
288 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
289 .show = queue_max_hw_sectors_show,
290};
291
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292static struct queue_sysfs_entry queue_max_segments_entry = {
293 .attr = {.name = "max_segments", .mode = S_IRUGO },
294 .show = queue_max_segments_show,
295};
296
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297static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
298 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
299 .show = queue_max_integrity_segments_show,
300};
301
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302static struct queue_sysfs_entry queue_max_segment_size_entry = {
303 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
304 .show = queue_max_segment_size_show,
305};
306
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307static struct queue_sysfs_entry queue_iosched_entry = {
308 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
309 .show = elv_iosched_show,
310 .store = elv_iosched_store,
311};
312
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313static struct queue_sysfs_entry queue_hw_sector_size_entry = {
314 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
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315 .show = queue_logical_block_size_show,
316};
317
318static struct queue_sysfs_entry queue_logical_block_size_entry = {
319 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
320 .show = queue_logical_block_size_show,
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321};
322
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323static struct queue_sysfs_entry queue_physical_block_size_entry = {
324 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
325 .show = queue_physical_block_size_show,
326};
327
328static struct queue_sysfs_entry queue_io_min_entry = {
329 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
330 .show = queue_io_min_show,
331};
332
333static struct queue_sysfs_entry queue_io_opt_entry = {
334 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
335 .show = queue_io_opt_show,
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336};
337
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338static struct queue_sysfs_entry queue_discard_granularity_entry = {
339 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
340 .show = queue_discard_granularity_show,
341};
342
343static struct queue_sysfs_entry queue_discard_max_entry = {
344 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
345 .show = queue_discard_max_show,
346};
347
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348static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
349 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
350 .show = queue_discard_zeroes_data_show,
351};
352
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BZ
353static struct queue_sysfs_entry queue_nonrot_entry = {
354 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
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355 .show = queue_show_nonrot,
356 .store = queue_store_nonrot,
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357};
358
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359static struct queue_sysfs_entry queue_nomerges_entry = {
360 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
361 .show = queue_nomerges_show,
362 .store = queue_nomerges_store,
363};
364
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365static struct queue_sysfs_entry queue_rq_affinity_entry = {
366 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
367 .show = queue_rq_affinity_show,
368 .store = queue_rq_affinity_store,
369};
370
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371static struct queue_sysfs_entry queue_iostats_entry = {
372 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
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373 .show = queue_show_iostats,
374 .store = queue_store_iostats,
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375};
376
e2e1a148
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377static struct queue_sysfs_entry queue_random_entry = {
378 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
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379 .show = queue_show_random,
380 .store = queue_store_random,
e2e1a148
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381};
382
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383static struct attribute *default_attrs[] = {
384 &queue_requests_entry.attr,
385 &queue_ra_entry.attr,
386 &queue_max_hw_sectors_entry.attr,
387 &queue_max_sectors_entry.attr,
c77a5710 388 &queue_max_segments_entry.attr,
13f05c8d 389 &queue_max_integrity_segments_entry.attr,
c77a5710 390 &queue_max_segment_size_entry.attr,
8324aa91 391 &queue_iosched_entry.attr,
e68b903c 392 &queue_hw_sector_size_entry.attr,
e1defc4f 393 &queue_logical_block_size_entry.attr,
c72758f3
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394 &queue_physical_block_size_entry.attr,
395 &queue_io_min_entry.attr,
396 &queue_io_opt_entry.attr,
86b37281
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397 &queue_discard_granularity_entry.attr,
398 &queue_discard_max_entry.attr,
98262f27 399 &queue_discard_zeroes_data_entry.attr,
1308835f 400 &queue_nonrot_entry.attr,
ac9fafa1 401 &queue_nomerges_entry.attr,
c7c22e4d 402 &queue_rq_affinity_entry.attr,
bc58ba94 403 &queue_iostats_entry.attr,
e2e1a148 404 &queue_random_entry.attr,
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405 NULL,
406};
407
408#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
409
410static ssize_t
411queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
412{
413 struct queue_sysfs_entry *entry = to_queue(attr);
414 struct request_queue *q =
415 container_of(kobj, struct request_queue, kobj);
416 ssize_t res;
417
418 if (!entry->show)
419 return -EIO;
420 mutex_lock(&q->sysfs_lock);
421 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
422 mutex_unlock(&q->sysfs_lock);
423 return -ENOENT;
424 }
425 res = entry->show(q, page);
426 mutex_unlock(&q->sysfs_lock);
427 return res;
428}
429
430static ssize_t
431queue_attr_store(struct kobject *kobj, struct attribute *attr,
432 const char *page, size_t length)
433{
434 struct queue_sysfs_entry *entry = to_queue(attr);
6728cb0e 435 struct request_queue *q;
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436 ssize_t res;
437
438 if (!entry->store)
439 return -EIO;
6728cb0e
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440
441 q = container_of(kobj, struct request_queue, kobj);
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442 mutex_lock(&q->sysfs_lock);
443 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
444 mutex_unlock(&q->sysfs_lock);
445 return -ENOENT;
446 }
447 res = entry->store(q, page, length);
448 mutex_unlock(&q->sysfs_lock);
449 return res;
450}
451
452/**
453 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
454 * @kobj: the kobj belonging of the request queue to be released
455 *
456 * Description:
457 * blk_cleanup_queue is the pair to blk_init_queue() or
458 * blk_queue_make_request(). It should be called when a request queue is
459 * being released; typically when a block device is being de-registered.
460 * Currently, its primary task it to free all the &struct request
461 * structures that were allocated to the queue and the queue itself.
462 *
463 * Caveat:
464 * Hopefully the low level driver will have finished any
465 * outstanding requests first...
466 **/
467static void blk_release_queue(struct kobject *kobj)
468{
469 struct request_queue *q =
470 container_of(kobj, struct request_queue, kobj);
471 struct request_list *rl = &q->rq;
472
473 blk_sync_queue(q);
474
475 if (rl->rq_pool)
476 mempool_destroy(rl->rq_pool);
477
478 if (q->queue_tags)
479 __blk_queue_free_tags(q);
480
481 blk_trace_shutdown(q);
482
483 bdi_destroy(&q->backing_dev_info);
484 kmem_cache_free(blk_requestq_cachep, q);
485}
486
52cf25d0 487static const struct sysfs_ops queue_sysfs_ops = {
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488 .show = queue_attr_show,
489 .store = queue_attr_store,
490};
491
492struct kobj_type blk_queue_ktype = {
493 .sysfs_ops = &queue_sysfs_ops,
494 .default_attrs = default_attrs,
495 .release = blk_release_queue,
496};
497
498int blk_register_queue(struct gendisk *disk)
499{
500 int ret;
1d54ad6d 501 struct device *dev = disk_to_dev(disk);
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502 struct request_queue *q = disk->queue;
503
fb199746 504 if (WARN_ON(!q))
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505 return -ENXIO;
506
1d54ad6d
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507 ret = blk_trace_init_sysfs(dev);
508 if (ret)
509 return ret;
510
c9059598 511 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
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LY
512 if (ret < 0) {
513 blk_trace_remove_sysfs(dev);
8324aa91 514 return ret;
ed5302d3 515 }
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516
517 kobject_uevent(&q->kobj, KOBJ_ADD);
518
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MP
519 if (!q->request_fn)
520 return 0;
521
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522 ret = elv_register_queue(q);
523 if (ret) {
524 kobject_uevent(&q->kobj, KOBJ_REMOVE);
525 kobject_del(&q->kobj);
80656b67 526 blk_trace_remove_sysfs(dev);
c87ffbb8 527 kobject_put(&dev->kobj);
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528 return ret;
529 }
530
531 return 0;
532}
533
534void blk_unregister_queue(struct gendisk *disk)
535{
536 struct request_queue *q = disk->queue;
537
fb199746
AM
538 if (WARN_ON(!q))
539 return;
540
48c0d4d4 541 if (q->request_fn)
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542 elv_unregister_queue(q);
543
48c0d4d4
ZK
544 kobject_uevent(&q->kobj, KOBJ_REMOVE);
545 kobject_del(&q->kobj);
546 blk_trace_remove_sysfs(disk_to_dev(disk));
547 kobject_put(&disk_to_dev(disk)->kobj);
8324aa91 548}