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v4.6
 
  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
 17struct 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
 23static ssize_t
 24queue_var_show(unsigned long var, char *page)
 25{
 26	return sprintf(page, "%lu\n", var);
 27}
 28
 29static ssize_t
 30queue_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
 
 
 
 
 
 
 
 
 
 
 
 
 
 44static ssize_t queue_requests_show(struct request_queue *q, char *page)
 45{
 46	return queue_var_show(q->nr_requests, (page));
 47}
 48
 49static ssize_t
 50queue_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
 76static 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_SHIFT - 10);
 80
 81	return queue_var_show(ra_kb, (page));
 82}
 83
 84static ssize_t
 85queue_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_SHIFT - 10);
 94
 95	return ret;
 96}
 97
 98static 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
105static 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
 
 
 
 
 
 
110static 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
115static 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_SIZE, (page));
121}
122
123static 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
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);
141}
142
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_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
155static 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
161static 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
184static 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
189static 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
196static ssize_t
197queue_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_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
220static 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)				\
228static ssize_t								\
229queue_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}									\
235static ssize_t								\
236queue_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
255QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
256QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
257QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
258#undef QUEUE_SYSFS_BIT_FNS
259
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
260static 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
266static 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
287static 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
295static ssize_t
296queue_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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
322static 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
327static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
350static 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
356static 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
362static 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
368static 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
373static struct queue_sysfs_entry queue_max_segments_entry = {
374	.attr = {.name = "max_segments", .mode = S_IRUGO },
375	.show = queue_max_segments_show,
376};
377
 
 
 
 
 
378static 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
383static 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
388static 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
394static 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
399static 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
404static 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
 
 
 
 
 
409static 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
414static 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
419static struct queue_sysfs_entry queue_discard_granularity_entry = {
420	.attr = {.name = "discard_granularity", .mode = S_IRUGO },
421	.show = queue_discard_granularity_show,
422};
423
424static 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
429static 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
435static 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
440static 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
 
 
 
 
 
 
 
 
 
 
445static 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
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
451static 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
457static 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
463static 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
469static 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
475static 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
481static 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
511static ssize_t
512queue_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
531static ssize_t
532queue_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
553static 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 **/
 
 
 
 
 
 
575static 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
609static const struct sysfs_ops queue_sysfs_ops = {
610	.show	= queue_attr_show,
611	.store	= queue_attr_store,
612};
613
614struct kobj_type blk_queue_ktype = {
615	.sysfs_ops	= &queue_sysfs_ops,
616	.default_attrs	= default_attrs,
617	.release	= blk_release_queue,
618};
619
 
 
 
 
620int 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
 
 
 
 
 
 
 
674void 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}
v5.9
   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Functions related to sysfs handling
   4 */
   5#include <linux/kernel.h>
   6#include <linux/slab.h>
   7#include <linux/module.h>
   8#include <linux/bio.h>
   9#include <linux/blkdev.h>
  10#include <linux/backing-dev.h>
  11#include <linux/blktrace_api.h>
  12#include <linux/blk-mq.h>
  13#include <linux/blk-cgroup.h>
  14#include <linux/debugfs.h>
  15
  16#include "blk.h"
  17#include "blk-mq.h"
  18#include "blk-mq-debugfs.h"
  19#include "blk-wbt.h"
  20
  21struct queue_sysfs_entry {
  22	struct attribute attr;
  23	ssize_t (*show)(struct request_queue *, char *);
  24	ssize_t (*store)(struct request_queue *, const char *, size_t);
  25};
  26
  27static ssize_t
  28queue_var_show(unsigned long var, char *page)
  29{
  30	return sprintf(page, "%lu\n", var);
  31}
  32
  33static ssize_t
  34queue_var_store(unsigned long *var, const char *page, size_t count)
  35{
  36	int err;
  37	unsigned long v;
  38
  39	err = kstrtoul(page, 10, &v);
  40	if (err || v > UINT_MAX)
  41		return -EINVAL;
  42
  43	*var = v;
  44
  45	return count;
  46}
  47
  48static ssize_t queue_var_store64(s64 *var, const char *page)
  49{
  50	int err;
  51	s64 v;
  52
  53	err = kstrtos64(page, 10, &v);
  54	if (err < 0)
  55		return err;
  56
  57	*var = v;
  58	return 0;
  59}
  60
  61static ssize_t queue_requests_show(struct request_queue *q, char *page)
  62{
  63	return queue_var_show(q->nr_requests, (page));
  64}
  65
  66static ssize_t
  67queue_requests_store(struct request_queue *q, const char *page, size_t count)
  68{
  69	unsigned long nr;
  70	int ret, err;
  71
  72	if (!queue_is_mq(q))
  73		return -EINVAL;
  74
  75	ret = queue_var_store(&nr, page, count);
  76	if (ret < 0)
  77		return ret;
  78
  79	if (nr < BLKDEV_MIN_RQ)
  80		nr = BLKDEV_MIN_RQ;
  81
  82	err = blk_mq_update_nr_requests(q, nr);
 
 
 
 
  83	if (err)
  84		return err;
  85
  86	return ret;
  87}
  88
  89static ssize_t queue_ra_show(struct request_queue *q, char *page)
  90{
  91	unsigned long ra_kb = q->backing_dev_info->ra_pages <<
  92					(PAGE_SHIFT - 10);
  93
  94	return queue_var_show(ra_kb, (page));
  95}
  96
  97static ssize_t
  98queue_ra_store(struct request_queue *q, const char *page, size_t count)
  99{
 100	unsigned long ra_kb;
 101	ssize_t ret = queue_var_store(&ra_kb, page, count);
 102
 103	if (ret < 0)
 104		return ret;
 105
 106	q->backing_dev_info->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
 107
 108	return ret;
 109}
 110
 111static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
 112{
 113	int max_sectors_kb = queue_max_sectors(q) >> 1;
 114
 115	return queue_var_show(max_sectors_kb, (page));
 116}
 117
 118static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
 119{
 120	return queue_var_show(queue_max_segments(q), (page));
 121}
 122
 123static ssize_t queue_max_discard_segments_show(struct request_queue *q,
 124		char *page)
 125{
 126	return queue_var_show(queue_max_discard_segments(q), (page));
 127}
 128
 129static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
 130{
 131	return queue_var_show(q->limits.max_integrity_segments, (page));
 132}
 133
 134static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
 135{
 136	return queue_var_show(queue_max_segment_size(q), (page));
 
 
 
 137}
 138
 139static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
 140{
 141	return queue_var_show(queue_logical_block_size(q), page);
 142}
 143
 144static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
 145{
 146	return queue_var_show(queue_physical_block_size(q), page);
 147}
 148
 149static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
 150{
 151	return queue_var_show(q->limits.chunk_sectors, page);
 152}
 153
 154static ssize_t queue_io_min_show(struct request_queue *q, char *page)
 155{
 156	return queue_var_show(queue_io_min(q), page);
 157}
 158
 159static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
 160{
 161	return queue_var_show(queue_io_opt(q), page);
 162}
 163
 164static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
 165{
 166	return queue_var_show(q->limits.discard_granularity, page);
 167}
 168
 169static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
 170{
 171
 172	return sprintf(page, "%llu\n",
 173		(unsigned long long)q->limits.max_hw_discard_sectors << 9);
 174}
 175
 176static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
 177{
 178	return sprintf(page, "%llu\n",
 179		       (unsigned long long)q->limits.max_discard_sectors << 9);
 180}
 181
 182static ssize_t queue_discard_max_store(struct request_queue *q,
 183				       const char *page, size_t count)
 184{
 185	unsigned long max_discard;
 186	ssize_t ret = queue_var_store(&max_discard, page, count);
 187
 188	if (ret < 0)
 189		return ret;
 190
 191	if (max_discard & (q->limits.discard_granularity - 1))
 192		return -EINVAL;
 193
 194	max_discard >>= 9;
 195	if (max_discard > UINT_MAX)
 196		return -EINVAL;
 197
 198	if (max_discard > q->limits.max_hw_discard_sectors)
 199		max_discard = q->limits.max_hw_discard_sectors;
 200
 201	q->limits.max_discard_sectors = max_discard;
 202	return ret;
 203}
 204
 205static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
 206{
 207	return queue_var_show(0, page);
 208}
 209
 210static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
 211{
 212	return sprintf(page, "%llu\n",
 213		(unsigned long long)q->limits.max_write_same_sectors << 9);
 214}
 215
 216static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
 217{
 218	return sprintf(page, "%llu\n",
 219		(unsigned long long)q->limits.max_write_zeroes_sectors << 9);
 220}
 221
 222static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
 223{
 224	unsigned long long max_sectors = q->limits.max_zone_append_sectors;
 225
 226	return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT);
 227}
 228
 229static ssize_t
 230queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
 231{
 232	unsigned long max_sectors_kb,
 233		max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
 234			page_kb = 1 << (PAGE_SHIFT - 10);
 235	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
 236
 237	if (ret < 0)
 238		return ret;
 239
 240	max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
 241					 q->limits.max_dev_sectors >> 1);
 242
 243	if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
 244		return -EINVAL;
 245
 246	spin_lock_irq(&q->queue_lock);
 247	q->limits.max_sectors = max_sectors_kb << 1;
 248	q->backing_dev_info->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
 249	spin_unlock_irq(&q->queue_lock);
 250
 251	return ret;
 252}
 253
 254static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
 255{
 256	int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
 257
 258	return queue_var_show(max_hw_sectors_kb, (page));
 259}
 260
 261#define QUEUE_SYSFS_BIT_FNS(name, flag, neg)				\
 262static ssize_t								\
 263queue_show_##name(struct request_queue *q, char *page)			\
 264{									\
 265	int bit;							\
 266	bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);		\
 267	return queue_var_show(neg ? !bit : bit, page);			\
 268}									\
 269static ssize_t								\
 270queue_store_##name(struct request_queue *q, const char *page, size_t count) \
 271{									\
 272	unsigned long val;						\
 273	ssize_t ret;							\
 274	ret = queue_var_store(&val, page, count);			\
 275	if (ret < 0)							\
 276		 return ret;						\
 277	if (neg)							\
 278		val = !val;						\
 279									\
 
 280	if (val)							\
 281		blk_queue_flag_set(QUEUE_FLAG_##flag, q);		\
 282	else								\
 283		blk_queue_flag_clear(QUEUE_FLAG_##flag, q);		\
 
 284	return ret;							\
 285}
 286
 287QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
 288QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
 289QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
 290#undef QUEUE_SYSFS_BIT_FNS
 291
 292static ssize_t queue_zoned_show(struct request_queue *q, char *page)
 293{
 294	switch (blk_queue_zoned_model(q)) {
 295	case BLK_ZONED_HA:
 296		return sprintf(page, "host-aware\n");
 297	case BLK_ZONED_HM:
 298		return sprintf(page, "host-managed\n");
 299	default:
 300		return sprintf(page, "none\n");
 301	}
 302}
 303
 304static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
 305{
 306	return queue_var_show(blk_queue_nr_zones(q), page);
 307}
 308
 309static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
 310{
 311	return queue_var_show(queue_max_open_zones(q), page);
 312}
 313
 314static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
 315{
 316	return queue_var_show(queue_max_active_zones(q), page);
 317}
 318
 319static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
 320{
 321	return queue_var_show((blk_queue_nomerges(q) << 1) |
 322			       blk_queue_noxmerges(q), page);
 323}
 324
 325static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
 326				    size_t count)
 327{
 328	unsigned long nm;
 329	ssize_t ret = queue_var_store(&nm, page, count);
 330
 331	if (ret < 0)
 332		return ret;
 333
 334	blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
 335	blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
 
 336	if (nm == 2)
 337		blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
 338	else if (nm)
 339		blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
 
 340
 341	return ret;
 342}
 343
 344static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
 345{
 346	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
 347	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
 348
 349	return queue_var_show(set << force, page);
 350}
 351
 352static ssize_t
 353queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
 354{
 355	ssize_t ret = -EINVAL;
 356#ifdef CONFIG_SMP
 357	unsigned long val;
 358
 359	ret = queue_var_store(&val, page, count);
 360	if (ret < 0)
 361		return ret;
 362
 
 363	if (val == 2) {
 364		blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 365		blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
 366	} else if (val == 1) {
 367		blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
 368		blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 369	} else if (val == 0) {
 370		blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
 371		blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
 372	}
 
 373#endif
 374	return ret;
 375}
 376
 377static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
 378{
 379	int val;
 380
 381	if (q->poll_nsec == BLK_MQ_POLL_CLASSIC)
 382		val = BLK_MQ_POLL_CLASSIC;
 383	else
 384		val = q->poll_nsec / 1000;
 385
 386	return sprintf(page, "%d\n", val);
 387}
 388
 389static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
 390				size_t count)
 391{
 392	int err, val;
 393
 394	if (!q->mq_ops || !q->mq_ops->poll)
 395		return -EINVAL;
 396
 397	err = kstrtoint(page, 10, &val);
 398	if (err < 0)
 399		return err;
 400
 401	if (val == BLK_MQ_POLL_CLASSIC)
 402		q->poll_nsec = BLK_MQ_POLL_CLASSIC;
 403	else if (val >= 0)
 404		q->poll_nsec = val * 1000;
 405	else
 406		return -EINVAL;
 407
 408	return count;
 409}
 410
 411static ssize_t queue_poll_show(struct request_queue *q, char *page)
 412{
 413	return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
 414}
 415
 416static ssize_t queue_poll_store(struct request_queue *q, const char *page,
 417				size_t count)
 418{
 419	unsigned long poll_on;
 420	ssize_t ret;
 421
 422	if (!q->tag_set || q->tag_set->nr_maps <= HCTX_TYPE_POLL ||
 423	    !q->tag_set->map[HCTX_TYPE_POLL].nr_queues)
 424		return -EINVAL;
 425
 426	ret = queue_var_store(&poll_on, page, count);
 427	if (ret < 0)
 428		return ret;
 429
 
 430	if (poll_on)
 431		blk_queue_flag_set(QUEUE_FLAG_POLL, q);
 432	else
 433		blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
 
 434
 435	return ret;
 436}
 437
 438static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
 439{
 440	return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout));
 441}
 442
 443static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
 444				  size_t count)
 445{
 446	unsigned int val;
 447	int err;
 448
 449	err = kstrtou32(page, 10, &val);
 450	if (err || val == 0)
 451		return -EINVAL;
 452
 453	blk_queue_rq_timeout(q, msecs_to_jiffies(val));
 454
 455	return count;
 456}
 457
 458static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
 459{
 460	if (!wbt_rq_qos(q))
 461		return -EINVAL;
 462
 463	return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
 464}
 465
 466static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
 467				  size_t count)
 468{
 469	struct rq_qos *rqos;
 470	ssize_t ret;
 471	s64 val;
 472
 473	ret = queue_var_store64(&val, page);
 474	if (ret < 0)
 475		return ret;
 476	if (val < -1)
 477		return -EINVAL;
 478
 479	rqos = wbt_rq_qos(q);
 480	if (!rqos) {
 481		ret = wbt_init(q);
 482		if (ret)
 483			return ret;
 484	}
 485
 486	if (val == -1)
 487		val = wbt_default_latency_nsec(q);
 488	else if (val >= 0)
 489		val *= 1000ULL;
 490
 491	if (wbt_get_min_lat(q) == val)
 492		return count;
 493
 494	/*
 495	 * Ensure that the queue is idled, in case the latency update
 496	 * ends up either enabling or disabling wbt completely. We can't
 497	 * have IO inflight if that happens.
 498	 */
 499	blk_mq_freeze_queue(q);
 500	blk_mq_quiesce_queue(q);
 501
 502	wbt_set_min_lat(q, val);
 503
 504	blk_mq_unquiesce_queue(q);
 505	blk_mq_unfreeze_queue(q);
 506
 507	return count;
 508}
 509
 510static ssize_t queue_wc_show(struct request_queue *q, char *page)
 511{
 512	if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
 513		return sprintf(page, "write back\n");
 514
 515	return sprintf(page, "write through\n");
 516}
 517
 518static ssize_t queue_wc_store(struct request_queue *q, const char *page,
 519			      size_t count)
 520{
 521	int set = -1;
 522
 523	if (!strncmp(page, "write back", 10))
 524		set = 1;
 525	else if (!strncmp(page, "write through", 13) ||
 526		 !strncmp(page, "none", 4))
 527		set = 0;
 528
 529	if (set == -1)
 530		return -EINVAL;
 531
 532	if (set)
 533		blk_queue_flag_set(QUEUE_FLAG_WC, q);
 534	else
 535		blk_queue_flag_clear(QUEUE_FLAG_WC, q);
 536
 537	return count;
 538}
 539
 540static ssize_t queue_fua_show(struct request_queue *q, char *page)
 541{
 542	return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
 543}
 544
 545static ssize_t queue_dax_show(struct request_queue *q, char *page)
 546{
 547	return queue_var_show(blk_queue_dax(q), page);
 548}
 549
 550static struct queue_sysfs_entry queue_requests_entry = {
 551	.attr = {.name = "nr_requests", .mode = 0644 },
 552	.show = queue_requests_show,
 553	.store = queue_requests_store,
 554};
 555
 556static struct queue_sysfs_entry queue_ra_entry = {
 557	.attr = {.name = "read_ahead_kb", .mode = 0644 },
 558	.show = queue_ra_show,
 559	.store = queue_ra_store,
 560};
 561
 562static struct queue_sysfs_entry queue_max_sectors_entry = {
 563	.attr = {.name = "max_sectors_kb", .mode = 0644 },
 564	.show = queue_max_sectors_show,
 565	.store = queue_max_sectors_store,
 566};
 567
 568static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
 569	.attr = {.name = "max_hw_sectors_kb", .mode = 0444 },
 570	.show = queue_max_hw_sectors_show,
 571};
 572
 573static struct queue_sysfs_entry queue_max_segments_entry = {
 574	.attr = {.name = "max_segments", .mode = 0444 },
 575	.show = queue_max_segments_show,
 576};
 577
 578static struct queue_sysfs_entry queue_max_discard_segments_entry = {
 579	.attr = {.name = "max_discard_segments", .mode = 0444 },
 580	.show = queue_max_discard_segments_show,
 581};
 582
 583static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
 584	.attr = {.name = "max_integrity_segments", .mode = 0444 },
 585	.show = queue_max_integrity_segments_show,
 586};
 587
 588static struct queue_sysfs_entry queue_max_segment_size_entry = {
 589	.attr = {.name = "max_segment_size", .mode = 0444 },
 590	.show = queue_max_segment_size_show,
 591};
 592
 593static struct queue_sysfs_entry queue_iosched_entry = {
 594	.attr = {.name = "scheduler", .mode = 0644 },
 595	.show = elv_iosched_show,
 596	.store = elv_iosched_store,
 597};
 598
 599static struct queue_sysfs_entry queue_hw_sector_size_entry = {
 600	.attr = {.name = "hw_sector_size", .mode = 0444 },
 601	.show = queue_logical_block_size_show,
 602};
 603
 604static struct queue_sysfs_entry queue_logical_block_size_entry = {
 605	.attr = {.name = "logical_block_size", .mode = 0444 },
 606	.show = queue_logical_block_size_show,
 607};
 608
 609static struct queue_sysfs_entry queue_physical_block_size_entry = {
 610	.attr = {.name = "physical_block_size", .mode = 0444 },
 611	.show = queue_physical_block_size_show,
 612};
 613
 614static struct queue_sysfs_entry queue_chunk_sectors_entry = {
 615	.attr = {.name = "chunk_sectors", .mode = 0444 },
 616	.show = queue_chunk_sectors_show,
 617};
 618
 619static struct queue_sysfs_entry queue_io_min_entry = {
 620	.attr = {.name = "minimum_io_size", .mode = 0444 },
 621	.show = queue_io_min_show,
 622};
 623
 624static struct queue_sysfs_entry queue_io_opt_entry = {
 625	.attr = {.name = "optimal_io_size", .mode = 0444 },
 626	.show = queue_io_opt_show,
 627};
 628
 629static struct queue_sysfs_entry queue_discard_granularity_entry = {
 630	.attr = {.name = "discard_granularity", .mode = 0444 },
 631	.show = queue_discard_granularity_show,
 632};
 633
 634static struct queue_sysfs_entry queue_discard_max_hw_entry = {
 635	.attr = {.name = "discard_max_hw_bytes", .mode = 0444 },
 636	.show = queue_discard_max_hw_show,
 637};
 638
 639static struct queue_sysfs_entry queue_discard_max_entry = {
 640	.attr = {.name = "discard_max_bytes", .mode = 0644 },
 641	.show = queue_discard_max_show,
 642	.store = queue_discard_max_store,
 643};
 644
 645static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
 646	.attr = {.name = "discard_zeroes_data", .mode = 0444 },
 647	.show = queue_discard_zeroes_data_show,
 648};
 649
 650static struct queue_sysfs_entry queue_write_same_max_entry = {
 651	.attr = {.name = "write_same_max_bytes", .mode = 0444 },
 652	.show = queue_write_same_max_show,
 653};
 654
 655static struct queue_sysfs_entry queue_write_zeroes_max_entry = {
 656	.attr = {.name = "write_zeroes_max_bytes", .mode = 0444 },
 657	.show = queue_write_zeroes_max_show,
 658};
 659
 660static struct queue_sysfs_entry queue_zone_append_max_entry = {
 661	.attr = {.name = "zone_append_max_bytes", .mode = 0444 },
 662	.show = queue_zone_append_max_show,
 663};
 664
 665static struct queue_sysfs_entry queue_nonrot_entry = {
 666	.attr = {.name = "rotational", .mode = 0644 },
 667	.show = queue_show_nonrot,
 668	.store = queue_store_nonrot,
 669};
 670
 671static struct queue_sysfs_entry queue_zoned_entry = {
 672	.attr = {.name = "zoned", .mode = 0444 },
 673	.show = queue_zoned_show,
 674};
 675
 676static struct queue_sysfs_entry queue_nr_zones_entry = {
 677	.attr = {.name = "nr_zones", .mode = 0444 },
 678	.show = queue_nr_zones_show,
 679};
 680
 681static struct queue_sysfs_entry queue_max_open_zones_entry = {
 682	.attr = {.name = "max_open_zones", .mode = 0444 },
 683	.show = queue_max_open_zones_show,
 684};
 685
 686static struct queue_sysfs_entry queue_max_active_zones_entry = {
 687	.attr = {.name = "max_active_zones", .mode = 0444 },
 688	.show = queue_max_active_zones_show,
 689};
 690
 691static struct queue_sysfs_entry queue_nomerges_entry = {
 692	.attr = {.name = "nomerges", .mode = 0644 },
 693	.show = queue_nomerges_show,
 694	.store = queue_nomerges_store,
 695};
 696
 697static struct queue_sysfs_entry queue_rq_affinity_entry = {
 698	.attr = {.name = "rq_affinity", .mode = 0644 },
 699	.show = queue_rq_affinity_show,
 700	.store = queue_rq_affinity_store,
 701};
 702
 703static struct queue_sysfs_entry queue_iostats_entry = {
 704	.attr = {.name = "iostats", .mode = 0644 },
 705	.show = queue_show_iostats,
 706	.store = queue_store_iostats,
 707};
 708
 709static struct queue_sysfs_entry queue_random_entry = {
 710	.attr = {.name = "add_random", .mode = 0644 },
 711	.show = queue_show_random,
 712	.store = queue_store_random,
 713};
 714
 715static struct queue_sysfs_entry queue_poll_entry = {
 716	.attr = {.name = "io_poll", .mode = 0644 },
 717	.show = queue_poll_show,
 718	.store = queue_poll_store,
 719};
 720
 721static struct queue_sysfs_entry queue_poll_delay_entry = {
 722	.attr = {.name = "io_poll_delay", .mode = 0644 },
 723	.show = queue_poll_delay_show,
 724	.store = queue_poll_delay_store,
 725};
 726
 727static struct queue_sysfs_entry queue_wc_entry = {
 728	.attr = {.name = "write_cache", .mode = 0644 },
 729	.show = queue_wc_show,
 730	.store = queue_wc_store,
 731};
 732
 733static struct queue_sysfs_entry queue_fua_entry = {
 734	.attr = {.name = "fua", .mode = 0444 },
 735	.show = queue_fua_show,
 736};
 737
 738static struct queue_sysfs_entry queue_dax_entry = {
 739	.attr = {.name = "dax", .mode = 0444 },
 740	.show = queue_dax_show,
 741};
 742
 743static struct queue_sysfs_entry queue_io_timeout_entry = {
 744	.attr = {.name = "io_timeout", .mode = 0644 },
 745	.show = queue_io_timeout_show,
 746	.store = queue_io_timeout_store,
 747};
 748
 749static struct queue_sysfs_entry queue_wb_lat_entry = {
 750	.attr = {.name = "wbt_lat_usec", .mode = 0644 },
 751	.show = queue_wb_lat_show,
 752	.store = queue_wb_lat_store,
 753};
 754
 755#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 756static struct queue_sysfs_entry throtl_sample_time_entry = {
 757	.attr = {.name = "throttle_sample_time", .mode = 0644 },
 758	.show = blk_throtl_sample_time_show,
 759	.store = blk_throtl_sample_time_store,
 760};
 761#endif
 762
 763static struct attribute *queue_attrs[] = {
 764	&queue_requests_entry.attr,
 765	&queue_ra_entry.attr,
 766	&queue_max_hw_sectors_entry.attr,
 767	&queue_max_sectors_entry.attr,
 768	&queue_max_segments_entry.attr,
 769	&queue_max_discard_segments_entry.attr,
 770	&queue_max_integrity_segments_entry.attr,
 771	&queue_max_segment_size_entry.attr,
 772	&queue_iosched_entry.attr,
 773	&queue_hw_sector_size_entry.attr,
 774	&queue_logical_block_size_entry.attr,
 775	&queue_physical_block_size_entry.attr,
 776	&queue_chunk_sectors_entry.attr,
 777	&queue_io_min_entry.attr,
 778	&queue_io_opt_entry.attr,
 779	&queue_discard_granularity_entry.attr,
 780	&queue_discard_max_entry.attr,
 781	&queue_discard_max_hw_entry.attr,
 782	&queue_discard_zeroes_data_entry.attr,
 783	&queue_write_same_max_entry.attr,
 784	&queue_write_zeroes_max_entry.attr,
 785	&queue_zone_append_max_entry.attr,
 786	&queue_nonrot_entry.attr,
 787	&queue_zoned_entry.attr,
 788	&queue_nr_zones_entry.attr,
 789	&queue_max_open_zones_entry.attr,
 790	&queue_max_active_zones_entry.attr,
 791	&queue_nomerges_entry.attr,
 792	&queue_rq_affinity_entry.attr,
 793	&queue_iostats_entry.attr,
 794	&queue_random_entry.attr,
 795	&queue_poll_entry.attr,
 796	&queue_wc_entry.attr,
 797	&queue_fua_entry.attr,
 798	&queue_dax_entry.attr,
 799	&queue_wb_lat_entry.attr,
 800	&queue_poll_delay_entry.attr,
 801	&queue_io_timeout_entry.attr,
 802#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
 803	&throtl_sample_time_entry.attr,
 804#endif
 805	NULL,
 806};
 807
 808static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
 809				int n)
 810{
 811	struct request_queue *q =
 812		container_of(kobj, struct request_queue, kobj);
 813
 814	if (attr == &queue_io_timeout_entry.attr &&
 815		(!q->mq_ops || !q->mq_ops->timeout))
 816			return 0;
 817
 818	if ((attr == &queue_max_open_zones_entry.attr ||
 819	     attr == &queue_max_active_zones_entry.attr) &&
 820	    !blk_queue_is_zoned(q))
 821		return 0;
 822
 823	return attr->mode;
 824}
 825
 826static struct attribute_group queue_attr_group = {
 827	.attrs = queue_attrs,
 828	.is_visible = queue_attr_visible,
 829};
 830
 831
 832#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
 833
 834static ssize_t
 835queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 836{
 837	struct queue_sysfs_entry *entry = to_queue(attr);
 838	struct request_queue *q =
 839		container_of(kobj, struct request_queue, kobj);
 840	ssize_t res;
 841
 842	if (!entry->show)
 843		return -EIO;
 844	mutex_lock(&q->sysfs_lock);
 
 
 
 
 845	res = entry->show(q, page);
 846	mutex_unlock(&q->sysfs_lock);
 847	return res;
 848}
 849
 850static ssize_t
 851queue_attr_store(struct kobject *kobj, struct attribute *attr,
 852		    const char *page, size_t length)
 853{
 854	struct queue_sysfs_entry *entry = to_queue(attr);
 855	struct request_queue *q;
 856	ssize_t res;
 857
 858	if (!entry->store)
 859		return -EIO;
 860
 861	q = container_of(kobj, struct request_queue, kobj);
 862	mutex_lock(&q->sysfs_lock);
 
 
 
 
 863	res = entry->store(q, page, length);
 864	mutex_unlock(&q->sysfs_lock);
 865	return res;
 866}
 867
 868static void blk_free_queue_rcu(struct rcu_head *rcu_head)
 869{
 870	struct request_queue *q = container_of(rcu_head, struct request_queue,
 871					       rcu_head);
 872	kmem_cache_free(blk_requestq_cachep, q);
 873}
 874
 875/* Unconfigure the I/O scheduler and dissociate from the cgroup controller. */
 876static void blk_exit_queue(struct request_queue *q)
 877{
 878	/*
 879	 * Since the I/O scheduler exit code may access cgroup information,
 880	 * perform I/O scheduler exit before disassociating from the block
 881	 * cgroup controller.
 882	 */
 883	if (q->elevator) {
 884		ioc_clear_queue(q);
 885		__elevator_exit(q, q->elevator);
 886		q->elevator = NULL;
 887	}
 888
 889	/*
 890	 * Remove all references to @q from the block cgroup controller before
 891	 * restoring @q->queue_lock to avoid that restoring this pointer causes
 892	 * e.g. blkcg_print_blkgs() to crash.
 893	 */
 894	blkcg_exit_queue(q);
 895
 896	/*
 897	 * Since the cgroup code may dereference the @q->backing_dev_info
 898	 * pointer, only decrease its reference count after having removed the
 899	 * association with the block cgroup controller.
 900	 */
 901	bdi_put(q->backing_dev_info);
 902}
 903
 904/**
 905 * blk_release_queue - releases all allocated resources of the request_queue
 906 * @kobj: pointer to a kobject, whose container is a request_queue
 907 *
 908 * This function releases all allocated resources of the request queue.
 909 *
 910 * The struct request_queue refcount is incremented with blk_get_queue() and
 911 * decremented with blk_put_queue(). Once the refcount reaches 0 this function
 912 * is called.
 
 
 
 913 *
 914 * For drivers that have a request_queue on a gendisk and added with
 915 * __device_add_disk() the refcount to request_queue will reach 0 with
 916 * the last put_disk() called by the driver. For drivers which don't use
 917 * __device_add_disk() this happens with blk_cleanup_queue().
 918 *
 919 * Drivers exist which depend on the release of the request_queue to be
 920 * synchronous, it should not be deferred.
 921 *
 922 * Context: can sleep
 923 */
 924static void blk_release_queue(struct kobject *kobj)
 925{
 926	struct request_queue *q =
 927		container_of(kobj, struct request_queue, kobj);
 928
 929	might_sleep();
 
 930
 931	if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
 932		blk_stat_remove_callback(q, q->poll_cb);
 933	blk_stat_free_callback(q->poll_cb);
 
 
 
 934
 935	blk_free_queue_stats(q->stats);
 936
 937	if (queue_is_mq(q))
 938		cancel_delayed_work_sync(&q->requeue_work);
 939
 940	blk_exit_queue(q);
 941
 942	blk_queue_free_zone_bitmaps(q);
 943
 944	if (queue_is_mq(q))
 945		blk_mq_release(q);
 946
 947	blk_trace_shutdown(q);
 948	mutex_lock(&q->debugfs_mutex);
 949	debugfs_remove_recursive(q->debugfs_dir);
 950	mutex_unlock(&q->debugfs_mutex);
 951
 952	if (queue_is_mq(q))
 953		blk_mq_debugfs_unregister(q);
 954
 955	bioset_exit(&q->bio_split);
 
 956
 957	ida_simple_remove(&blk_queue_ida, q->id);
 958	call_rcu(&q->rcu_head, blk_free_queue_rcu);
 959}
 960
 961static const struct sysfs_ops queue_sysfs_ops = {
 962	.show	= queue_attr_show,
 963	.store	= queue_attr_store,
 964};
 965
 966struct kobj_type blk_queue_ktype = {
 967	.sysfs_ops	= &queue_sysfs_ops,
 
 968	.release	= blk_release_queue,
 969};
 970
 971/**
 972 * blk_register_queue - register a block layer queue with sysfs
 973 * @disk: Disk of which the request queue should be registered with sysfs.
 974 */
 975int blk_register_queue(struct gendisk *disk)
 976{
 977	int ret;
 978	struct device *dev = disk_to_dev(disk);
 979	struct request_queue *q = disk->queue;
 980	bool has_elevator = false;
 981
 982	if (WARN_ON(!q))
 983		return -ENXIO;
 984
 985	WARN_ONCE(blk_queue_registered(q),
 986		  "%s is registering an already registered queue\n",
 987		  kobject_name(&dev->kobj));
 988
 989	/*
 990	 * SCSI probing may synchronously create and destroy a lot of
 991	 * request_queues for non-existent devices.  Shutting down a fully
 992	 * functional queue takes measureable wallclock time as RCU grace
 993	 * periods are involved.  To avoid excessive latency in these
 994	 * cases, a request_queue starts out in a degraded mode which is
 995	 * faster to shut down and is made fully functional here as
 996	 * request_queues for non-existent devices never get registered.
 997	 */
 998	if (!blk_queue_init_done(q)) {
 999		blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
1000		percpu_ref_switch_to_percpu(&q->q_usage_counter);
 
1001	}
1002
1003	ret = blk_trace_init_sysfs(dev);
1004	if (ret)
1005		return ret;
1006
1007	mutex_lock(&q->sysfs_dir_lock);
1008
1009	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
1010	if (ret < 0) {
1011		blk_trace_remove_sysfs(dev);
1012		goto unlock;
1013	}
1014
1015	ret = sysfs_create_group(&q->kobj, &queue_attr_group);
 
 
 
 
 
 
 
 
1016	if (ret) {
 
 
1017		blk_trace_remove_sysfs(dev);
1018		kobject_del(&q->kobj);
1019		kobject_put(&dev->kobj);
1020		goto unlock;
1021	}
1022
1023	mutex_lock(&q->debugfs_mutex);
1024	q->debugfs_dir = debugfs_create_dir(kobject_name(q->kobj.parent),
1025					    blk_debugfs_root);
1026	mutex_unlock(&q->debugfs_mutex);
1027
1028	if (queue_is_mq(q)) {
1029		__blk_mq_register_dev(dev, q);
1030		blk_mq_debugfs_register(q);
1031	}
1032
1033	mutex_lock(&q->sysfs_lock);
1034	if (q->elevator) {
1035		ret = elv_register_queue(q, false);
1036		if (ret) {
1037			mutex_unlock(&q->sysfs_lock);
1038			mutex_unlock(&q->sysfs_dir_lock);
1039			kobject_del(&q->kobj);
1040			blk_trace_remove_sysfs(dev);
1041			kobject_put(&dev->kobj);
1042			return ret;
1043		}
1044		has_elevator = true;
1045	}
1046
1047	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
1048	wbt_enable_default(q);
1049	blk_throtl_register_queue(q);
1050
1051	/* Now everything is ready and send out KOBJ_ADD uevent */
1052	kobject_uevent(&q->kobj, KOBJ_ADD);
1053	if (has_elevator)
1054		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
1055	mutex_unlock(&q->sysfs_lock);
1056
1057	ret = 0;
1058unlock:
1059	mutex_unlock(&q->sysfs_dir_lock);
1060	return ret;
1061}
1062EXPORT_SYMBOL_GPL(blk_register_queue);
1063
1064/**
1065 * blk_unregister_queue - counterpart of blk_register_queue()
1066 * @disk: Disk of which the request queue should be unregistered from sysfs.
1067 *
1068 * Note: the caller is responsible for guaranteeing that this function is called
1069 * after blk_register_queue() has finished.
1070 */
1071void blk_unregister_queue(struct gendisk *disk)
1072{
1073	struct request_queue *q = disk->queue;
1074
1075	if (WARN_ON(!q))
1076		return;
1077
1078	/* Return early if disk->queue was never registered. */
1079	if (!blk_queue_registered(q))
1080		return;
1081
1082	/*
1083	 * Since sysfs_remove_dir() prevents adding new directory entries
1084	 * before removal of existing entries starts, protect against
1085	 * concurrent elv_iosched_store() calls.
1086	 */
1087	mutex_lock(&q->sysfs_lock);
1088	blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
1089	mutex_unlock(&q->sysfs_lock);
1090
1091	mutex_lock(&q->sysfs_dir_lock);
1092	/*
1093	 * Remove the sysfs attributes before unregistering the queue data
1094	 * structures that can be modified through sysfs.
1095	 */
1096	if (queue_is_mq(q))
1097		blk_mq_unregister_dev(disk_to_dev(disk), q);
1098
1099	kobject_uevent(&q->kobj, KOBJ_REMOVE);
1100	kobject_del(&q->kobj);
1101	blk_trace_remove_sysfs(disk_to_dev(disk));
1102
1103	mutex_lock(&q->sysfs_lock);
1104	if (q->elevator)
1105		elv_unregister_queue(q);
1106	mutex_unlock(&q->sysfs_lock);
1107	mutex_unlock(&q->sysfs_dir_lock);
1108
1109	kobject_put(&disk_to_dev(disk)->kobj);
1110}