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v3.15
 
  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#include <linux/blk-mq.h>
 11
 12#include "blk.h"
 13#include "blk-cgroup.h"
 14#include "blk-mq.h"
 
 
 
 
 
 
 15
 16struct queue_sysfs_entry {
 17	struct attribute attr;
 18	ssize_t (*show)(struct request_queue *, char *);
 19	ssize_t (*store)(struct request_queue *, const char *, size_t);
 20};
 21
 22static ssize_t
 23queue_var_show(unsigned long var, char *page)
 24{
 25	return sprintf(page, "%lu\n", var);
 26}
 27
 28static ssize_t
 29queue_var_store(unsigned long *var, const char *page, size_t count)
 30{
 31	int err;
 32	unsigned long v;
 33
 34	err = kstrtoul(page, 10, &v);
 35	if (err || v > UINT_MAX)
 36		return -EINVAL;
 37
 38	*var = v;
 39
 40	return count;
 41}
 42
 43static ssize_t queue_requests_show(struct request_queue *q, char *page)
 44{
 45	return queue_var_show(q->nr_requests, (page));
 46}
 47
 48static ssize_t
 49queue_requests_store(struct request_queue *q, const char *page, size_t count)
 50{
 51	struct request_list *rl;
 52	unsigned long nr;
 53	int ret;
 54
 55	if (!q->request_fn)
 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	spin_lock_irq(q->queue_lock);
 66	q->nr_requests = nr;
 67	blk_queue_congestion_threshold(q);
 68
 69	/* congestion isn't cgroup aware and follows root blkcg for now */
 70	rl = &q->root_rl;
 71
 72	if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
 73		blk_set_queue_congested(q, BLK_RW_SYNC);
 74	else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
 75		blk_clear_queue_congested(q, BLK_RW_SYNC);
 76
 77	if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
 78		blk_set_queue_congested(q, BLK_RW_ASYNC);
 79	else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
 80		blk_clear_queue_congested(q, BLK_RW_ASYNC);
 81
 82	blk_queue_for_each_rl(rl, q) {
 83		if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
 84			blk_set_rl_full(rl, BLK_RW_SYNC);
 85		} else {
 86			blk_clear_rl_full(rl, BLK_RW_SYNC);
 87			wake_up(&rl->wait[BLK_RW_SYNC]);
 88		}
 89
 90		if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
 91			blk_set_rl_full(rl, BLK_RW_ASYNC);
 92		} else {
 93			blk_clear_rl_full(rl, BLK_RW_ASYNC);
 94			wake_up(&rl->wait[BLK_RW_ASYNC]);
 95		}
 96	}
 97
 98	spin_unlock_irq(q->queue_lock);
 99	return ret;
100}
101
102static ssize_t queue_ra_show(struct request_queue *q, char *page)
103{
104	unsigned long ra_kb = q->backing_dev_info.ra_pages <<
105					(PAGE_CACHE_SHIFT - 10);
106
107	return queue_var_show(ra_kb, (page));
 
 
 
108}
109
110static ssize_t
111queue_ra_store(struct request_queue *q, const char *page, size_t count)
112{
113	unsigned long ra_kb;
114	ssize_t ret = queue_var_store(&ra_kb, page, count);
115
 
 
 
116	if (ret < 0)
117		return ret;
118
119	q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
120
121	return ret;
122}
123
124static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
125{
126	int max_sectors_kb = queue_max_sectors(q) >> 1;
127
128	return queue_var_show(max_sectors_kb, (page));
129}
130
131static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
132{
133	return queue_var_show(queue_max_segments(q), (page));
 
 
 
 
 
 
134}
135
136static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
137{
138	return queue_var_show(q->limits.max_integrity_segments, (page));
139}
140
141static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
142{
143	if (blk_queue_cluster(q))
144		return queue_var_show(queue_max_segment_size(q), (page));
145
146	return queue_var_show(PAGE_CACHE_SIZE, (page));
147}
148
149static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
150{
151	return queue_var_show(queue_logical_block_size(q), page);
152}
153
154static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
155{
156	return queue_var_show(queue_physical_block_size(q), page);
157}
158
 
 
 
 
 
159static ssize_t queue_io_min_show(struct request_queue *q, char *page)
160{
161	return queue_var_show(queue_io_min(q), page);
162}
163
164static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
165{
166	return queue_var_show(queue_io_opt(q), page);
167}
168
169static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
170{
171	return queue_var_show(q->limits.discard_granularity, page);
172}
173
 
 
 
 
 
 
 
174static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
175{
176	return sprintf(page, "%llu\n",
177		       (unsigned long long)q->limits.max_discard_sectors << 9);
178}
179
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
180static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
181{
182	return queue_var_show(queue_discard_zeroes_data(q), page);
183}
184
185static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
186{
 
 
 
 
 
187	return sprintf(page, "%llu\n",
188		(unsigned long long)q->limits.max_write_same_sectors << 9);
 
 
 
 
 
 
189}
190
 
 
 
 
 
 
191
192static ssize_t
193queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
194{
195	unsigned long max_sectors_kb,
196		max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
197			page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
198	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
199
 
200	if (ret < 0)
201		return ret;
202
203	if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
204		return -EINVAL;
205
206	spin_lock_irq(q->queue_lock);
207	q->limits.max_sectors = max_sectors_kb << 1;
208	spin_unlock_irq(q->queue_lock);
209
210	return ret;
211}
212
213static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
214{
215	int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
216
217	return queue_var_show(max_hw_sectors_kb, (page));
 
 
 
 
 
 
 
 
 
 
218}
219
220#define QUEUE_SYSFS_BIT_FNS(name, flag, neg)				\
221static ssize_t								\
222queue_show_##name(struct request_queue *q, char *page)			\
223{									\
224	int bit;							\
225	bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);		\
226	return queue_var_show(neg ? !bit : bit, page);			\
227}									\
228static ssize_t								\
229queue_store_##name(struct request_queue *q, const char *page, size_t count) \
230{									\
231	unsigned long val;						\
232	ssize_t ret;							\
233	ret = queue_var_store(&val, page, count);			\
234	if (ret < 0)							\
235		 return ret;						\
236	if (neg)							\
237		val = !val;						\
238									\
239	spin_lock_irq(q->queue_lock);					\
240	if (val)							\
241		queue_flag_set(QUEUE_FLAG_##flag, q);			\
242	else								\
243		queue_flag_clear(QUEUE_FLAG_##flag, q);			\
244	spin_unlock_irq(q->queue_lock);					\
245	return ret;							\
246}
247
248QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
249QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
250QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
 
251#undef QUEUE_SYSFS_BIT_FNS
252
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
253static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
254{
255	return queue_var_show((blk_queue_nomerges(q) << 1) |
256			       blk_queue_noxmerges(q), page);
257}
258
259static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
260				    size_t count)
261{
262	unsigned long nm;
263	ssize_t ret = queue_var_store(&nm, page, count);
264
265	if (ret < 0)
266		return ret;
267
268	spin_lock_irq(q->queue_lock);
269	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
270	queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
271	if (nm == 2)
272		queue_flag_set(QUEUE_FLAG_NOMERGES, q);
273	else if (nm)
274		queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
275	spin_unlock_irq(q->queue_lock);
276
277	return ret;
278}
279
280static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
281{
282	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
283	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
284
285	return queue_var_show(set << force, page);
286}
287
288static ssize_t
289queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
290{
291	ssize_t ret = -EINVAL;
292#ifdef CONFIG_SMP
293	unsigned long val;
294
295	ret = queue_var_store(&val, page, count);
296	if (ret < 0)
297		return ret;
298
299	spin_lock_irq(q->queue_lock);
300	if (val == 2) {
301		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
302		queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
303	} else if (val == 1) {
304		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
305		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
306	} else if (val == 0) {
307		queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
308		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
309	}
310	spin_unlock_irq(q->queue_lock);
311#endif
312	return ret;
313}
314
315static struct queue_sysfs_entry queue_requests_entry = {
316	.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
317	.show = queue_requests_show,
318	.store = queue_requests_store,
319};
320
321static struct queue_sysfs_entry queue_ra_entry = {
322	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
323	.show = queue_ra_show,
324	.store = queue_ra_store,
325};
326
327static struct queue_sysfs_entry queue_max_sectors_entry = {
328	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
329	.show = queue_max_sectors_show,
330	.store = queue_max_sectors_store,
331};
332
333static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
334	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
335	.show = queue_max_hw_sectors_show,
336};
 
 
 
 
 
337
338static struct queue_sysfs_entry queue_max_segments_entry = {
339	.attr = {.name = "max_segments", .mode = S_IRUGO },
340	.show = queue_max_segments_show,
341};
342
343static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
344	.attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
345	.show = queue_max_integrity_segments_show,
346};
 
347
348static struct queue_sysfs_entry queue_max_segment_size_entry = {
349	.attr = {.name = "max_segment_size", .mode = S_IRUGO },
350	.show = queue_max_segment_size_show,
351};
352
353static struct queue_sysfs_entry queue_iosched_entry = {
354	.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
355	.show = elv_iosched_show,
356	.store = elv_iosched_store,
357};
 
 
 
 
 
 
 
358
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
359static struct queue_sysfs_entry queue_hw_sector_size_entry = {
360	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
361	.show = queue_logical_block_size_show,
362};
363
364static struct queue_sysfs_entry queue_logical_block_size_entry = {
365	.attr = {.name = "logical_block_size", .mode = S_IRUGO },
366	.show = queue_logical_block_size_show,
367};
368
369static struct queue_sysfs_entry queue_physical_block_size_entry = {
370	.attr = {.name = "physical_block_size", .mode = S_IRUGO },
371	.show = queue_physical_block_size_show,
372};
 
373
374static struct queue_sysfs_entry queue_io_min_entry = {
375	.attr = {.name = "minimum_io_size", .mode = S_IRUGO },
376	.show = queue_io_min_show,
377};
378
379static struct queue_sysfs_entry queue_io_opt_entry = {
380	.attr = {.name = "optimal_io_size", .mode = S_IRUGO },
381	.show = queue_io_opt_show,
382};
383
384static struct queue_sysfs_entry queue_discard_granularity_entry = {
385	.attr = {.name = "discard_granularity", .mode = S_IRUGO },
386	.show = queue_discard_granularity_show,
387};
388
389static struct queue_sysfs_entry queue_discard_max_entry = {
390	.attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
391	.show = queue_discard_max_show,
392};
393
394static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
395	.attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
396	.show = queue_discard_zeroes_data_show,
397};
398
399static struct queue_sysfs_entry queue_write_same_max_entry = {
400	.attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
401	.show = queue_write_same_max_show,
402};
 
 
403
404static struct queue_sysfs_entry queue_nonrot_entry = {
405	.attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
406	.show = queue_show_nonrot,
407	.store = queue_store_nonrot,
408};
409
410static struct queue_sysfs_entry queue_nomerges_entry = {
411	.attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
412	.show = queue_nomerges_show,
413	.store = queue_nomerges_store,
414};
 
415
416static struct queue_sysfs_entry queue_rq_affinity_entry = {
417	.attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
418	.show = queue_rq_affinity_show,
419	.store = queue_rq_affinity_store,
420};
421
422static struct queue_sysfs_entry queue_iostats_entry = {
423	.attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
424	.show = queue_show_iostats,
425	.store = queue_store_iostats,
426};
427
428static struct queue_sysfs_entry queue_random_entry = {
429	.attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
430	.show = queue_show_random,
431	.store = queue_store_random,
432};
 
 
433
434static struct attribute *default_attrs[] = {
435	&queue_requests_entry.attr,
 
 
 
 
 
 
 
 
 
 
 
436	&queue_ra_entry.attr,
437	&queue_max_hw_sectors_entry.attr,
438	&queue_max_sectors_entry.attr,
439	&queue_max_segments_entry.attr,
 
440	&queue_max_integrity_segments_entry.attr,
441	&queue_max_segment_size_entry.attr,
442	&queue_iosched_entry.attr,
443	&queue_hw_sector_size_entry.attr,
444	&queue_logical_block_size_entry.attr,
445	&queue_physical_block_size_entry.attr,
 
446	&queue_io_min_entry.attr,
447	&queue_io_opt_entry.attr,
448	&queue_discard_granularity_entry.attr,
449	&queue_discard_max_entry.attr,
 
450	&queue_discard_zeroes_data_entry.attr,
451	&queue_write_same_max_entry.attr,
 
 
 
452	&queue_nonrot_entry.attr,
 
 
 
 
453	&queue_nomerges_entry.attr,
454	&queue_rq_affinity_entry.attr,
455	&queue_iostats_entry.attr,
 
456	&queue_random_entry.attr,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
457	NULL,
458};
459
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
460#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
461
462static ssize_t
463queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
464{
465	struct queue_sysfs_entry *entry = to_queue(attr);
466	struct request_queue *q =
467		container_of(kobj, struct request_queue, kobj);
468	ssize_t res;
469
470	if (!entry->show)
471		return -EIO;
472	mutex_lock(&q->sysfs_lock);
473	if (blk_queue_dying(q)) {
474		mutex_unlock(&q->sysfs_lock);
475		return -ENOENT;
476	}
477	res = entry->show(q, page);
478	mutex_unlock(&q->sysfs_lock);
479	return res;
480}
481
482static ssize_t
483queue_attr_store(struct kobject *kobj, struct attribute *attr,
484		    const char *page, size_t length)
485{
486	struct queue_sysfs_entry *entry = to_queue(attr);
487	struct request_queue *q;
 
488	ssize_t res;
489
490	if (!entry->store)
491		return -EIO;
492
493	q = container_of(kobj, struct request_queue, kobj);
494	mutex_lock(&q->sysfs_lock);
495	if (blk_queue_dying(q)) {
496		mutex_unlock(&q->sysfs_lock);
497		return -ENOENT;
498	}
499	res = entry->store(q, page, length);
500	mutex_unlock(&q->sysfs_lock);
501	return res;
502}
503
504static void blk_free_queue_rcu(struct rcu_head *rcu_head)
505{
506	struct request_queue *q = container_of(rcu_head, struct request_queue,
507					       rcu_head);
508	kmem_cache_free(blk_requestq_cachep, q);
509}
510
511/**
512 * blk_release_queue: - release a &struct request_queue when it is no longer needed
513 * @kobj:    the kobj belonging to the request queue to be released
514 *
515 * Description:
516 *     blk_release_queue is the pair to blk_init_queue() or
517 *     blk_queue_make_request().  It should be called when a request queue is
518 *     being released; typically when a block device is being de-registered.
519 *     Currently, its primary task it to free all the &struct request
520 *     structures that were allocated to the queue and the queue itself.
521 *
522 * Caveat:
523 *     Hopefully the low level driver will have finished any
524 *     outstanding requests first...
525 **/
526static void blk_release_queue(struct kobject *kobj)
527{
528	struct request_queue *q =
529		container_of(kobj, struct request_queue, kobj);
530
531	blk_sync_queue(q);
532
533	blkcg_exit_queue(q);
534
535	if (q->elevator) {
536		spin_lock_irq(q->queue_lock);
537		ioc_clear_queue(q);
538		spin_unlock_irq(q->queue_lock);
539		elevator_exit(q->elevator);
540	}
541
542	blk_exit_rl(&q->root_rl);
543
544	if (q->queue_tags)
545		__blk_queue_free_tags(q);
546
547	percpu_counter_destroy(&q->mq_usage_counter);
548
549	if (q->mq_ops)
550		blk_mq_free_queue(q);
551
552	kfree(q->flush_rq);
553
554	blk_trace_shutdown(q);
555
556	bdi_destroy(&q->backing_dev_info);
557
558	ida_simple_remove(&blk_queue_ida, q->id);
559	call_rcu(&q->rcu_head, blk_free_queue_rcu);
560}
561
562static const struct sysfs_ops queue_sysfs_ops = {
563	.show	= queue_attr_show,
564	.store	= queue_attr_store,
565};
566
567struct kobj_type blk_queue_ktype = {
 
 
 
 
 
 
 
 
 
 
 
 
568	.sysfs_ops	= &queue_sysfs_ops,
569	.default_attrs	= default_attrs,
570	.release	= blk_release_queue,
571};
572
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
573int blk_register_queue(struct gendisk *disk)
574{
575	int ret;
576	struct device *dev = disk_to_dev(disk);
577	struct request_queue *q = disk->queue;
 
578
579	if (WARN_ON(!q))
580		return -ENXIO;
 
 
 
581
582	/*
583	 * Initialization must be complete by now.  Finish the initial
584	 * bypass from queue allocation.
585	 */
586	blk_queue_bypass_end(q);
587	queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
 
 
 
 
 
 
588
589	ret = blk_trace_init_sysfs(dev);
590	if (ret)
591		return ret;
592
593	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
594	if (ret < 0) {
595		blk_trace_remove_sysfs(dev);
596		return ret;
597	}
598
599	kobject_uevent(&q->kobj, KOBJ_ADD);
600
601	if (q->mq_ops)
602		blk_mq_register_disk(disk);
603
604	if (!q->request_fn)
605		return 0;
 
 
 
 
 
 
 
 
606
607	ret = elv_register_queue(q);
608	if (ret) {
609		kobject_uevent(&q->kobj, KOBJ_REMOVE);
610		kobject_del(&q->kobj);
611		blk_trace_remove_sysfs(dev);
612		kobject_put(&dev->kobj);
613		return ret;
 
 
 
 
 
614	}
615
616	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
617}
618
 
 
 
 
 
 
 
619void blk_unregister_queue(struct gendisk *disk)
620{
621	struct request_queue *q = disk->queue;
622
623	if (WARN_ON(!q))
624		return;
625
626	if (q->mq_ops)
627		blk_mq_unregister_disk(disk);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
628
629	if (q->request_fn)
630		elv_unregister_queue(q);
 
 
631
632	kobject_uevent(&q->kobj, KOBJ_REMOVE);
633	kobject_del(&q->kobj);
634	blk_trace_remove_sysfs(disk_to_dev(disk));
635	kobject_put(&disk_to_dev(disk)->kobj);
636}
v6.9.4
  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/debugfs.h>
 13
 14#include "blk.h"
 
 15#include "blk-mq.h"
 16#include "blk-mq-debugfs.h"
 17#include "blk-mq-sched.h"
 18#include "blk-rq-qos.h"
 19#include "blk-wbt.h"
 20#include "blk-cgroup.h"
 21#include "blk-throttle.h"
 22
 23struct queue_sysfs_entry {
 24	struct attribute attr;
 25	ssize_t (*show)(struct request_queue *, char *);
 26	ssize_t (*store)(struct request_queue *, const char *, size_t);
 27};
 28
 29static ssize_t
 30queue_var_show(unsigned long var, char *page)
 31{
 32	return sprintf(page, "%lu\n", var);
 33}
 34
 35static ssize_t
 36queue_var_store(unsigned long *var, const char *page, size_t count)
 37{
 38	int err;
 39	unsigned long v;
 40
 41	err = kstrtoul(page, 10, &v);
 42	if (err || v > UINT_MAX)
 43		return -EINVAL;
 44
 45	*var = v;
 46
 47	return count;
 48}
 49
 50static ssize_t queue_requests_show(struct request_queue *q, char *page)
 51{
 52	return queue_var_show(q->nr_requests, page);
 53}
 54
 55static ssize_t
 56queue_requests_store(struct request_queue *q, const char *page, size_t count)
 57{
 
 58	unsigned long nr;
 59	int ret, err;
 60
 61	if (!queue_is_mq(q))
 62		return -EINVAL;
 63
 64	ret = queue_var_store(&nr, page, count);
 65	if (ret < 0)
 66		return ret;
 67
 68	if (nr < BLKDEV_MIN_RQ)
 69		nr = BLKDEV_MIN_RQ;
 70
 71	err = blk_mq_update_nr_requests(q, nr);
 72	if (err)
 73		return err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 74
 
 75	return ret;
 76}
 77
 78static ssize_t queue_ra_show(struct request_queue *q, char *page)
 79{
 80	unsigned long ra_kb;
 
 81
 82	if (!q->disk)
 83		return -EINVAL;
 84	ra_kb = q->disk->bdi->ra_pages << (PAGE_SHIFT - 10);
 85	return queue_var_show(ra_kb, page);
 86}
 87
 88static ssize_t
 89queue_ra_store(struct request_queue *q, const char *page, size_t count)
 90{
 91	unsigned long ra_kb;
 92	ssize_t ret;
 93
 94	if (!q->disk)
 95		return -EINVAL;
 96	ret = queue_var_store(&ra_kb, page, count);
 97	if (ret < 0)
 98		return ret;
 99	q->disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
 
 
100	return ret;
101}
102
103static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
104{
105	int max_sectors_kb = queue_max_sectors(q) >> 1;
106
107	return queue_var_show(max_sectors_kb, page);
108}
109
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_discard_segments_show(struct request_queue *q,
116		char *page)
117{
118	return queue_var_show(queue_max_discard_segments(q), page);
119}
120
121static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
122{
123	return queue_var_show(q->limits.max_integrity_segments, page);
124}
125
126static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
127{
128	return queue_var_show(queue_max_segment_size(q), page);
 
 
 
129}
130
131static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
132{
133	return queue_var_show(queue_logical_block_size(q), page);
134}
135
136static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
137{
138	return queue_var_show(queue_physical_block_size(q), page);
139}
140
141static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
142{
143	return queue_var_show(q->limits.chunk_sectors, page);
144}
145
146static ssize_t queue_io_min_show(struct request_queue *q, char *page)
147{
148	return queue_var_show(queue_io_min(q), page);
149}
150
151static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
152{
153	return queue_var_show(queue_io_opt(q), page);
154}
155
156static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
157{
158	return queue_var_show(q->limits.discard_granularity, page);
159}
160
161static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
162{
163
164	return sprintf(page, "%llu\n",
165		(unsigned long long)q->limits.max_hw_discard_sectors << 9);
166}
167
168static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
169{
170	return sprintf(page, "%llu\n",
171		       (unsigned long long)q->limits.max_discard_sectors << 9);
172}
173
174static ssize_t queue_discard_max_store(struct request_queue *q,
175				       const char *page, size_t count)
176{
177	unsigned long max_discard_bytes;
178	struct queue_limits lim;
179	ssize_t ret;
180	int err;
181
182	ret = queue_var_store(&max_discard_bytes, page, count);
183	if (ret < 0)
184		return ret;
185
186	if (max_discard_bytes & (q->limits.discard_granularity - 1))
187		return -EINVAL;
188
189	if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX)
190		return -EINVAL;
191
192	blk_mq_freeze_queue(q);
193	lim = queue_limits_start_update(q);
194	lim.max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
195	err = queue_limits_commit_update(q, &lim);
196	blk_mq_unfreeze_queue(q);
197
198	if (err)
199		return err;
200	return ret;
201}
202
203static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
204{
205	return queue_var_show(0, page);
206}
207
208static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
209{
210	return queue_var_show(0, page);
211}
212
213static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
214{
215	return sprintf(page, "%llu\n",
216		(unsigned long long)q->limits.max_write_zeroes_sectors << 9);
217}
218
219static ssize_t queue_zone_write_granularity_show(struct request_queue *q,
220						 char *page)
221{
222	return queue_var_show(queue_zone_write_granularity(q), page);
223}
224
225static ssize_t queue_zone_append_max_show(struct request_queue *q, char *page)
226{
227	unsigned long long max_sectors = q->limits.max_zone_append_sectors;
228
229	return sprintf(page, "%llu\n", max_sectors << SECTOR_SHIFT);
230}
231
232static ssize_t
233queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
234{
235	unsigned long max_sectors_kb;
236	struct queue_limits lim;
237	ssize_t ret;
238	int err;
239
240	ret = queue_var_store(&max_sectors_kb, page, count);
241	if (ret < 0)
242		return ret;
243
244	blk_mq_freeze_queue(q);
245	lim = queue_limits_start_update(q);
246	lim.max_user_sectors = max_sectors_kb << 1;
247	err = queue_limits_commit_update(q, &lim);
248	blk_mq_unfreeze_queue(q);
249	if (err)
250		return err;
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
261static ssize_t queue_virt_boundary_mask_show(struct request_queue *q, char *page)
262{
263	return queue_var_show(q->limits.virt_boundary_mask, page);
264}
265
266static ssize_t queue_dma_alignment_show(struct request_queue *q, char *page)
267{
268	return queue_var_show(queue_dma_alignment(q), page);
269}
270
271#define QUEUE_SYSFS_BIT_FNS(name, flag, neg)				\
272static ssize_t								\
273queue_##name##_show(struct request_queue *q, char *page)		\
274{									\
275	int bit;							\
276	bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);		\
277	return queue_var_show(neg ? !bit : bit, page);			\
278}									\
279static ssize_t								\
280queue_##name##_store(struct request_queue *q, const char *page, size_t count) \
281{									\
282	unsigned long val;						\
283	ssize_t ret;							\
284	ret = queue_var_store(&val, page, count);			\
285	if (ret < 0)							\
286		 return ret;						\
287	if (neg)							\
288		val = !val;						\
289									\
 
290	if (val)							\
291		blk_queue_flag_set(QUEUE_FLAG_##flag, q);		\
292	else								\
293		blk_queue_flag_clear(QUEUE_FLAG_##flag, q);		\
 
294	return ret;							\
295}
296
297QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
298QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
299QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
300QUEUE_SYSFS_BIT_FNS(stable_writes, STABLE_WRITES, 0);
301#undef QUEUE_SYSFS_BIT_FNS
302
303static ssize_t queue_zoned_show(struct request_queue *q, char *page)
304{
305	if (blk_queue_is_zoned(q))
306		return sprintf(page, "host-managed\n");
307	return sprintf(page, "none\n");
308}
309
310static ssize_t queue_nr_zones_show(struct request_queue *q, char *page)
311{
312	return queue_var_show(disk_nr_zones(q->disk), page);
313}
314
315static ssize_t queue_max_open_zones_show(struct request_queue *q, char *page)
316{
317	return queue_var_show(bdev_max_open_zones(q->disk->part0), page);
318}
319
320static ssize_t queue_max_active_zones_show(struct request_queue *q, char *page)
321{
322	return queue_var_show(bdev_max_active_zones(q->disk->part0), page);
323}
324
325static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
326{
327	return queue_var_show((blk_queue_nomerges(q) << 1) |
328			       blk_queue_noxmerges(q), page);
329}
330
331static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
332				    size_t count)
333{
334	unsigned long nm;
335	ssize_t ret = queue_var_store(&nm, page, count);
336
337	if (ret < 0)
338		return ret;
339
340	blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
341	blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
 
342	if (nm == 2)
343		blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
344	else if (nm)
345		blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
 
346
347	return ret;
348}
349
350static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
351{
352	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
353	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
354
355	return queue_var_show(set << force, page);
356}
357
358static ssize_t
359queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
360{
361	ssize_t ret = -EINVAL;
362#ifdef CONFIG_SMP
363	unsigned long val;
364
365	ret = queue_var_store(&val, page, count);
366	if (ret < 0)
367		return ret;
368
 
369	if (val == 2) {
370		blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
371		blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
372	} else if (val == 1) {
373		blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
374		blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
375	} else if (val == 0) {
376		blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
377		blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
378	}
 
379#endif
380	return ret;
381}
382
383static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
384{
385	return sprintf(page, "%d\n", -1);
386}
 
387
388static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
389				size_t count)
390{
391	return count;
392}
393
394static ssize_t queue_poll_show(struct request_queue *q, char *page)
395{
396	return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
397}
 
398
399static ssize_t queue_poll_store(struct request_queue *q, const char *page,
400				size_t count)
401{
402	if (!test_bit(QUEUE_FLAG_POLL, &q->queue_flags))
403		return -EINVAL;
404	pr_info_ratelimited("writes to the poll attribute are ignored.\n");
405	pr_info_ratelimited("please use driver specific parameters instead.\n");
406	return count;
407}
408
409static ssize_t queue_io_timeout_show(struct request_queue *q, char *page)
410{
411	return sprintf(page, "%u\n", jiffies_to_msecs(q->rq_timeout));
412}
413
414static ssize_t queue_io_timeout_store(struct request_queue *q, const char *page,
415				  size_t count)
416{
417	unsigned int val;
418	int err;
419
420	err = kstrtou32(page, 10, &val);
421	if (err || val == 0)
422		return -EINVAL;
 
423
424	blk_queue_rq_timeout(q, msecs_to_jiffies(val));
425
426	return count;
427}
428
429static ssize_t queue_wc_show(struct request_queue *q, char *page)
430{
431	if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
432		return sprintf(page, "write back\n");
433
434	return sprintf(page, "write through\n");
435}
436
437static ssize_t queue_wc_store(struct request_queue *q, const char *page,
438			      size_t count)
439{
440	if (!strncmp(page, "write back", 10)) {
441		if (!test_bit(QUEUE_FLAG_HW_WC, &q->queue_flags))
442			return -EINVAL;
443		blk_queue_flag_set(QUEUE_FLAG_WC, q);
444	} else if (!strncmp(page, "write through", 13) ||
445		 !strncmp(page, "none", 4)) {
446		blk_queue_flag_clear(QUEUE_FLAG_WC, q);
447	} else {
448		return -EINVAL;
449	}
450
451	return count;
452}
453
454static ssize_t queue_fua_show(struct request_queue *q, char *page)
455{
456	return sprintf(page, "%u\n", test_bit(QUEUE_FLAG_FUA, &q->queue_flags));
457}
458
459static ssize_t queue_dax_show(struct request_queue *q, char *page)
460{
461	return queue_var_show(blk_queue_dax(q), page);
462}
463
464#define QUEUE_RO_ENTRY(_prefix, _name)			\
465static struct queue_sysfs_entry _prefix##_entry = {	\
466	.attr	= { .name = _name, .mode = 0444 },	\
467	.show	= _prefix##_show,			\
468};
469
470#define QUEUE_RW_ENTRY(_prefix, _name)			\
471static struct queue_sysfs_entry _prefix##_entry = {	\
472	.attr	= { .name = _name, .mode = 0644 },	\
473	.show	= _prefix##_show,			\
474	.store	= _prefix##_store,			\
475};
476
477QUEUE_RW_ENTRY(queue_requests, "nr_requests");
478QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");
479QUEUE_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
480QUEUE_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
481QUEUE_RO_ENTRY(queue_max_segments, "max_segments");
482QUEUE_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");
483QUEUE_RO_ENTRY(queue_max_segment_size, "max_segment_size");
484QUEUE_RW_ENTRY(elv_iosched, "scheduler");
485
486QUEUE_RO_ENTRY(queue_logical_block_size, "logical_block_size");
487QUEUE_RO_ENTRY(queue_physical_block_size, "physical_block_size");
488QUEUE_RO_ENTRY(queue_chunk_sectors, "chunk_sectors");
489QUEUE_RO_ENTRY(queue_io_min, "minimum_io_size");
490QUEUE_RO_ENTRY(queue_io_opt, "optimal_io_size");
491
492QUEUE_RO_ENTRY(queue_max_discard_segments, "max_discard_segments");
493QUEUE_RO_ENTRY(queue_discard_granularity, "discard_granularity");
494QUEUE_RO_ENTRY(queue_discard_max_hw, "discard_max_hw_bytes");
495QUEUE_RW_ENTRY(queue_discard_max, "discard_max_bytes");
496QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data");
497
498QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes");
499QUEUE_RO_ENTRY(queue_write_zeroes_max, "write_zeroes_max_bytes");
500QUEUE_RO_ENTRY(queue_zone_append_max, "zone_append_max_bytes");
501QUEUE_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity");
502
503QUEUE_RO_ENTRY(queue_zoned, "zoned");
504QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones");
505QUEUE_RO_ENTRY(queue_max_open_zones, "max_open_zones");
506QUEUE_RO_ENTRY(queue_max_active_zones, "max_active_zones");
507
508QUEUE_RW_ENTRY(queue_nomerges, "nomerges");
509QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity");
510QUEUE_RW_ENTRY(queue_poll, "io_poll");
511QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay");
512QUEUE_RW_ENTRY(queue_wc, "write_cache");
513QUEUE_RO_ENTRY(queue_fua, "fua");
514QUEUE_RO_ENTRY(queue_dax, "dax");
515QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
516QUEUE_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
517QUEUE_RO_ENTRY(queue_dma_alignment, "dma_alignment");
518
519#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
520QUEUE_RW_ENTRY(blk_throtl_sample_time, "throttle_sample_time");
521#endif
522
523/* legacy alias for logical_block_size: */
524static struct queue_sysfs_entry queue_hw_sector_size_entry = {
525	.attr = {.name = "hw_sector_size", .mode = 0444 },
526	.show = queue_logical_block_size_show,
527};
528
529QUEUE_RW_ENTRY(queue_nonrot, "rotational");
530QUEUE_RW_ENTRY(queue_iostats, "iostats");
531QUEUE_RW_ENTRY(queue_random, "add_random");
532QUEUE_RW_ENTRY(queue_stable_writes, "stable_writes");
533
534#ifdef CONFIG_BLK_WBT
535static ssize_t queue_var_store64(s64 *var, const char *page)
536{
537	int err;
538	s64 v;
539
540	err = kstrtos64(page, 10, &v);
541	if (err < 0)
542		return err;
 
543
544	*var = v;
545	return 0;
546}
 
547
548static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
549{
550	if (!wbt_rq_qos(q))
551		return -EINVAL;
552
553	if (wbt_disabled(q))
554		return sprintf(page, "0\n");
 
 
555
556	return sprintf(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
557}
 
 
558
559static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
560				  size_t count)
561{
562	struct rq_qos *rqos;
563	ssize_t ret;
564	s64 val;
565
566	ret = queue_var_store64(&val, page);
567	if (ret < 0)
568		return ret;
569	if (val < -1)
570		return -EINVAL;
571
572	rqos = wbt_rq_qos(q);
573	if (!rqos) {
574		ret = wbt_init(q->disk);
575		if (ret)
576			return ret;
577	}
578
579	if (val == -1)
580		val = wbt_default_latency_nsec(q);
581	else if (val >= 0)
582		val *= 1000ULL;
 
583
584	if (wbt_get_min_lat(q) == val)
585		return count;
 
 
 
586
587	/*
588	 * Ensure that the queue is idled, in case the latency update
589	 * ends up either enabling or disabling wbt completely. We can't
590	 * have IO inflight if that happens.
591	 */
592	blk_mq_freeze_queue(q);
593	blk_mq_quiesce_queue(q);
594
595	wbt_set_min_lat(q, val);
596
597	blk_mq_unquiesce_queue(q);
598	blk_mq_unfreeze_queue(q);
599
600	return count;
601}
602
603QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec");
604#endif
605
606/* Common attributes for bio-based and request-based queues. */
607static struct attribute *queue_attrs[] = {
608	&queue_ra_entry.attr,
609	&queue_max_hw_sectors_entry.attr,
610	&queue_max_sectors_entry.attr,
611	&queue_max_segments_entry.attr,
612	&queue_max_discard_segments_entry.attr,
613	&queue_max_integrity_segments_entry.attr,
614	&queue_max_segment_size_entry.attr,
 
615	&queue_hw_sector_size_entry.attr,
616	&queue_logical_block_size_entry.attr,
617	&queue_physical_block_size_entry.attr,
618	&queue_chunk_sectors_entry.attr,
619	&queue_io_min_entry.attr,
620	&queue_io_opt_entry.attr,
621	&queue_discard_granularity_entry.attr,
622	&queue_discard_max_entry.attr,
623	&queue_discard_max_hw_entry.attr,
624	&queue_discard_zeroes_data_entry.attr,
625	&queue_write_same_max_entry.attr,
626	&queue_write_zeroes_max_entry.attr,
627	&queue_zone_append_max_entry.attr,
628	&queue_zone_write_granularity_entry.attr,
629	&queue_nonrot_entry.attr,
630	&queue_zoned_entry.attr,
631	&queue_nr_zones_entry.attr,
632	&queue_max_open_zones_entry.attr,
633	&queue_max_active_zones_entry.attr,
634	&queue_nomerges_entry.attr,
 
635	&queue_iostats_entry.attr,
636	&queue_stable_writes_entry.attr,
637	&queue_random_entry.attr,
638	&queue_poll_entry.attr,
639	&queue_wc_entry.attr,
640	&queue_fua_entry.attr,
641	&queue_dax_entry.attr,
642	&queue_poll_delay_entry.attr,
643#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
644	&blk_throtl_sample_time_entry.attr,
645#endif
646	&queue_virt_boundary_mask_entry.attr,
647	&queue_dma_alignment_entry.attr,
648	NULL,
649};
650
651/* Request-based queue attributes that are not relevant for bio-based queues. */
652static struct attribute *blk_mq_queue_attrs[] = {
653	&queue_requests_entry.attr,
654	&elv_iosched_entry.attr,
655	&queue_rq_affinity_entry.attr,
656	&queue_io_timeout_entry.attr,
657#ifdef CONFIG_BLK_WBT
658	&queue_wb_lat_entry.attr,
659#endif
660	NULL,
661};
662
663static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
664				int n)
665{
666	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
667	struct request_queue *q = disk->queue;
668
669	if ((attr == &queue_max_open_zones_entry.attr ||
670	     attr == &queue_max_active_zones_entry.attr) &&
671	    !blk_queue_is_zoned(q))
672		return 0;
673
674	return attr->mode;
675}
676
677static umode_t blk_mq_queue_attr_visible(struct kobject *kobj,
678					 struct attribute *attr, int n)
679{
680	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
681	struct request_queue *q = disk->queue;
682
683	if (!queue_is_mq(q))
684		return 0;
685
686	if (attr == &queue_io_timeout_entry.attr && !q->mq_ops->timeout)
687		return 0;
688
689	return attr->mode;
690}
691
692static struct attribute_group queue_attr_group = {
693	.attrs = queue_attrs,
694	.is_visible = queue_attr_visible,
695};
696
697static struct attribute_group blk_mq_queue_attr_group = {
698	.attrs = blk_mq_queue_attrs,
699	.is_visible = blk_mq_queue_attr_visible,
700};
701
702#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
703
704static ssize_t
705queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
706{
707	struct queue_sysfs_entry *entry = to_queue(attr);
708	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
709	struct request_queue *q = disk->queue;
710	ssize_t res;
711
712	if (!entry->show)
713		return -EIO;
714	mutex_lock(&q->sysfs_lock);
 
 
 
 
715	res = entry->show(q, page);
716	mutex_unlock(&q->sysfs_lock);
717	return res;
718}
719
720static ssize_t
721queue_attr_store(struct kobject *kobj, struct attribute *attr,
722		    const char *page, size_t length)
723{
724	struct queue_sysfs_entry *entry = to_queue(attr);
725	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
726	struct request_queue *q = disk->queue;
727	ssize_t res;
728
729	if (!entry->store)
730		return -EIO;
731
 
732	mutex_lock(&q->sysfs_lock);
 
 
 
 
733	res = entry->store(q, page, length);
734	mutex_unlock(&q->sysfs_lock);
735	return res;
736}
737
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
738static const struct sysfs_ops queue_sysfs_ops = {
739	.show	= queue_attr_show,
740	.store	= queue_attr_store,
741};
742
743static const struct attribute_group *blk_queue_attr_groups[] = {
744	&queue_attr_group,
745	&blk_mq_queue_attr_group,
746	NULL
747};
748
749static void blk_queue_release(struct kobject *kobj)
750{
751	/* nothing to do here, all data is associated with the parent gendisk */
752}
753
754static const struct kobj_type blk_queue_ktype = {
755	.default_groups = blk_queue_attr_groups,
756	.sysfs_ops	= &queue_sysfs_ops,
757	.release	= blk_queue_release,
 
758};
759
760static void blk_debugfs_remove(struct gendisk *disk)
761{
762	struct request_queue *q = disk->queue;
763
764	mutex_lock(&q->debugfs_mutex);
765	blk_trace_shutdown(q);
766	debugfs_remove_recursive(q->debugfs_dir);
767	q->debugfs_dir = NULL;
768	q->sched_debugfs_dir = NULL;
769	q->rqos_debugfs_dir = NULL;
770	mutex_unlock(&q->debugfs_mutex);
771}
772
773/**
774 * blk_register_queue - register a block layer queue with sysfs
775 * @disk: Disk of which the request queue should be registered with sysfs.
776 */
777int blk_register_queue(struct gendisk *disk)
778{
 
 
779	struct request_queue *q = disk->queue;
780	int ret;
781
782	mutex_lock(&q->sysfs_dir_lock);
783	kobject_init(&disk->queue_kobj, &blk_queue_ktype);
784	ret = kobject_add(&disk->queue_kobj, &disk_to_dev(disk)->kobj, "queue");
785	if (ret < 0)
786		goto out_put_queue_kobj;
787
788	if (queue_is_mq(q)) {
789		ret = blk_mq_sysfs_register(disk);
790		if (ret)
791			goto out_put_queue_kobj;
792	}
793	mutex_lock(&q->sysfs_lock);
794
795	mutex_lock(&q->debugfs_mutex);
796	q->debugfs_dir = debugfs_create_dir(disk->disk_name, blk_debugfs_root);
797	if (queue_is_mq(q))
798		blk_mq_debugfs_register(q);
799	mutex_unlock(&q->debugfs_mutex);
800
801	ret = disk_register_independent_access_ranges(disk);
802	if (ret)
803		goto out_debugfs_remove;
804
805	if (q->elevator) {
806		ret = elv_register_queue(q, false);
807		if (ret)
808			goto out_unregister_ia_ranges;
809	}
810
811	ret = blk_crypto_sysfs_register(disk);
812	if (ret)
813		goto out_elv_unregister;
 
814
815	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
816	wbt_enable_default(disk);
817	blk_throtl_register(disk);
818
819	/* Now everything is ready and send out KOBJ_ADD uevent */
820	kobject_uevent(&disk->queue_kobj, KOBJ_ADD);
821	if (q->elevator)
822		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
823	mutex_unlock(&q->sysfs_lock);
824	mutex_unlock(&q->sysfs_dir_lock);
825
826	/*
827	 * SCSI probing may synchronously create and destroy a lot of
828	 * request_queues for non-existent devices.  Shutting down a fully
829	 * functional queue takes measureable wallclock time as RCU grace
830	 * periods are involved.  To avoid excessive latency in these
831	 * cases, a request_queue starts out in a degraded mode which is
832	 * faster to shut down and is made fully functional here as
833	 * request_queues for non-existent devices never get registered.
834	 */
835	if (!blk_queue_init_done(q)) {
836		blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
837		percpu_ref_switch_to_percpu(&q->q_usage_counter);
838	}
839
840	return ret;
841
842out_elv_unregister:
843	elv_unregister_queue(q);
844out_unregister_ia_ranges:
845	disk_unregister_independent_access_ranges(disk);
846out_debugfs_remove:
847	blk_debugfs_remove(disk);
848	mutex_unlock(&q->sysfs_lock);
849out_put_queue_kobj:
850	kobject_put(&disk->queue_kobj);
851	mutex_unlock(&q->sysfs_dir_lock);
852	return ret;
853}
854
855/**
856 * blk_unregister_queue - counterpart of blk_register_queue()
857 * @disk: Disk of which the request queue should be unregistered from sysfs.
858 *
859 * Note: the caller is responsible for guaranteeing that this function is called
860 * after blk_register_queue() has finished.
861 */
862void blk_unregister_queue(struct gendisk *disk)
863{
864	struct request_queue *q = disk->queue;
865
866	if (WARN_ON(!q))
867		return;
868
869	/* Return early if disk->queue was never registered. */
870	if (!blk_queue_registered(q))
871		return;
872
873	/*
874	 * Since sysfs_remove_dir() prevents adding new directory entries
875	 * before removal of existing entries starts, protect against
876	 * concurrent elv_iosched_store() calls.
877	 */
878	mutex_lock(&q->sysfs_lock);
879	blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
880	mutex_unlock(&q->sysfs_lock);
881
882	mutex_lock(&q->sysfs_dir_lock);
883	/*
884	 * Remove the sysfs attributes before unregistering the queue data
885	 * structures that can be modified through sysfs.
886	 */
887	if (queue_is_mq(q))
888		blk_mq_sysfs_unregister(disk);
889	blk_crypto_sysfs_unregister(disk);
890
891	mutex_lock(&q->sysfs_lock);
892	elv_unregister_queue(q);
893	disk_unregister_independent_access_ranges(disk);
894	mutex_unlock(&q->sysfs_lock);
895
896	/* Now that we've deleted all child objects, we can delete the queue. */
897	kobject_uevent(&disk->queue_kobj, KOBJ_REMOVE);
898	kobject_del(&disk->queue_kobj);
899	mutex_unlock(&q->sysfs_dir_lock);
900
901	blk_debugfs_remove(disk);
 
 
 
902}