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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}