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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}
v4.17
  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
 15#include "blk.h"
 
 16#include "blk-mq.h"
 17#include "blk-mq-debugfs.h"
 18#include "blk-wbt.h"
 19
 20struct queue_sysfs_entry {
 21	struct attribute attr;
 22	ssize_t (*show)(struct request_queue *, char *);
 23	ssize_t (*store)(struct request_queue *, const char *, size_t);
 24};
 25
 26static ssize_t
 27queue_var_show(unsigned long var, char *page)
 28{
 29	return sprintf(page, "%lu\n", var);
 30}
 31
 32static ssize_t
 33queue_var_store(unsigned long *var, const char *page, size_t count)
 34{
 35	int err;
 36	unsigned long v;
 37
 38	err = kstrtoul(page, 10, &v);
 39	if (err || v > UINT_MAX)
 40		return -EINVAL;
 41
 42	*var = v;
 43
 44	return count;
 45}
 46
 47static ssize_t queue_var_store64(s64 *var, const char *page)
 48{
 49	int err;
 50	s64 v;
 51
 52	err = kstrtos64(page, 10, &v);
 53	if (err < 0)
 54		return err;
 55
 56	*var = v;
 57	return 0;
 58}
 59
 60static ssize_t queue_requests_show(struct request_queue *q, char *page)
 61{
 62	return queue_var_show(q->nr_requests, (page));
 63}
 64
 65static ssize_t
 66queue_requests_store(struct request_queue *q, const char *page, size_t count)
 67{
 
 68	unsigned long nr;
 69	int ret, err;
 70
 71	if (!q->request_fn && !q->mq_ops)
 72		return -EINVAL;
 73
 74	ret = queue_var_store(&nr, page, count);
 75	if (ret < 0)
 76		return ret;
 77
 78	if (nr < BLKDEV_MIN_RQ)
 79		nr = BLKDEV_MIN_RQ;
 80
 81	if (q->request_fn)
 82		err = blk_update_nr_requests(q, nr);
 83	else
 84		err = blk_mq_update_nr_requests(q, nr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 85
 86	if (err)
 87		return err;
 
 
 
 
 
 88
 
 89	return ret;
 90}
 91
 92static ssize_t queue_ra_show(struct request_queue *q, char *page)
 93{
 94	unsigned long ra_kb = q->backing_dev_info->ra_pages <<
 95					(PAGE_SHIFT - 10);
 96
 97	return queue_var_show(ra_kb, (page));
 98}
 99
100static ssize_t
101queue_ra_store(struct request_queue *q, const char *page, size_t count)
102{
103	unsigned long ra_kb;
104	ssize_t ret = queue_var_store(&ra_kb, page, count);
105
106	if (ret < 0)
107		return ret;
108
109	q->backing_dev_info->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
110
111	return ret;
112}
113
114static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
115{
116	int max_sectors_kb = queue_max_sectors(q) >> 1;
117
118	return queue_var_show(max_sectors_kb, (page));
119}
120
121static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
122{
123	return queue_var_show(queue_max_segments(q), (page));
124}
125
126static ssize_t queue_max_discard_segments_show(struct request_queue *q,
127		char *page)
128{
129	return queue_var_show(queue_max_discard_segments(q), (page));
130}
131
132static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
133{
134	return queue_var_show(q->limits.max_integrity_segments, (page));
135}
136
137static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
138{
139	if (blk_queue_cluster(q))
140		return queue_var_show(queue_max_segment_size(q), (page));
141
142	return queue_var_show(PAGE_SIZE, (page));
143}
144
145static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
146{
147	return queue_var_show(queue_logical_block_size(q), page);
148}
149
150static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
151{
152	return queue_var_show(queue_physical_block_size(q), page);
153}
154
155static ssize_t queue_chunk_sectors_show(struct request_queue *q, char *page)
156{
157	return queue_var_show(q->limits.chunk_sectors, page);
158}
159
160static ssize_t queue_io_min_show(struct request_queue *q, char *page)
161{
162	return queue_var_show(queue_io_min(q), page);
163}
164
165static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
166{
167	return queue_var_show(queue_io_opt(q), page);
168}
169
170static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
171{
172	return queue_var_show(q->limits.discard_granularity, page);
173}
174
175static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
176{
177
178	return sprintf(page, "%llu\n",
179		(unsigned long long)q->limits.max_hw_discard_sectors << 9);
180}
181
182static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
183{
184	return sprintf(page, "%llu\n",
185		       (unsigned long long)q->limits.max_discard_sectors << 9);
186}
187
188static ssize_t queue_discard_max_store(struct request_queue *q,
189				       const char *page, size_t count)
190{
191	unsigned long max_discard;
192	ssize_t ret = queue_var_store(&max_discard, page, count);
193
194	if (ret < 0)
195		return ret;
196
197	if (max_discard & (q->limits.discard_granularity - 1))
198		return -EINVAL;
199
200	max_discard >>= 9;
201	if (max_discard > UINT_MAX)
202		return -EINVAL;
203
204	if (max_discard > q->limits.max_hw_discard_sectors)
205		max_discard = q->limits.max_hw_discard_sectors;
206
207	q->limits.max_discard_sectors = max_discard;
208	return ret;
209}
210
211static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
212{
213	return queue_var_show(0, page);
214}
215
216static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
217{
218	return sprintf(page, "%llu\n",
219		(unsigned long long)q->limits.max_write_same_sectors << 9);
220}
221
222static ssize_t queue_write_zeroes_max_show(struct request_queue *q, char *page)
223{
224	return sprintf(page, "%llu\n",
225		(unsigned long long)q->limits.max_write_zeroes_sectors << 9);
226}
227
228static ssize_t
229queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
230{
231	unsigned long max_sectors_kb,
232		max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
233			page_kb = 1 << (PAGE_SHIFT - 10);
234	ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
235
236	if (ret < 0)
237		return ret;
238
239	max_hw_sectors_kb = min_not_zero(max_hw_sectors_kb, (unsigned long)
240					 q->limits.max_dev_sectors >> 1);
241
242	if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
243		return -EINVAL;
244
245	spin_lock_irq(q->queue_lock);
246	q->limits.max_sectors = max_sectors_kb << 1;
247	q->backing_dev_info->io_pages = max_sectors_kb >> (PAGE_SHIFT - 10);
248	spin_unlock_irq(q->queue_lock);
249
250	return ret;
251}
252
253static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
254{
255	int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
256
257	return queue_var_show(max_hw_sectors_kb, (page));
258}
259
260#define QUEUE_SYSFS_BIT_FNS(name, flag, neg)				\
261static ssize_t								\
262queue_show_##name(struct request_queue *q, char *page)			\
263{									\
264	int bit;							\
265	bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);		\
266	return queue_var_show(neg ? !bit : bit, page);			\
267}									\
268static ssize_t								\
269queue_store_##name(struct request_queue *q, const char *page, size_t count) \
270{									\
271	unsigned long val;						\
272	ssize_t ret;							\
273	ret = queue_var_store(&val, page, count);			\
274	if (ret < 0)							\
275		 return ret;						\
276	if (neg)							\
277		val = !val;						\
278									\
 
279	if (val)							\
280		blk_queue_flag_set(QUEUE_FLAG_##flag, q);		\
281	else								\
282		blk_queue_flag_clear(QUEUE_FLAG_##flag, q);		\
 
283	return ret;							\
284}
285
286QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
287QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
288QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
289#undef QUEUE_SYSFS_BIT_FNS
290
291static ssize_t queue_zoned_show(struct request_queue *q, char *page)
292{
293	switch (blk_queue_zoned_model(q)) {
294	case BLK_ZONED_HA:
295		return sprintf(page, "host-aware\n");
296	case BLK_ZONED_HM:
297		return sprintf(page, "host-managed\n");
298	default:
299		return sprintf(page, "none\n");
300	}
301}
302
303static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
304{
305	return queue_var_show((blk_queue_nomerges(q) << 1) |
306			       blk_queue_noxmerges(q), page);
307}
308
309static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
310				    size_t count)
311{
312	unsigned long nm;
313	ssize_t ret = queue_var_store(&nm, page, count);
314
315	if (ret < 0)
316		return ret;
317
318	spin_lock_irq(q->queue_lock);
319	queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
320	queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
321	if (nm == 2)
322		queue_flag_set(QUEUE_FLAG_NOMERGES, q);
323	else if (nm)
324		queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
325	spin_unlock_irq(q->queue_lock);
326
327	return ret;
328}
329
330static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
331{
332	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
333	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
334
335	return queue_var_show(set << force, page);
336}
337
338static ssize_t
339queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
340{
341	ssize_t ret = -EINVAL;
342#ifdef CONFIG_SMP
343	unsigned long val;
344
345	ret = queue_var_store(&val, page, count);
346	if (ret < 0)
347		return ret;
348
349	spin_lock_irq(q->queue_lock);
350	if (val == 2) {
351		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
352		queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
353	} else if (val == 1) {
354		queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
355		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
356	} else if (val == 0) {
357		queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
358		queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
359	}
360	spin_unlock_irq(q->queue_lock);
361#endif
362	return ret;
363}
364
365static ssize_t queue_poll_delay_show(struct request_queue *q, char *page)
366{
367	int val;
368
369	if (q->poll_nsec == -1)
370		val = -1;
371	else
372		val = q->poll_nsec / 1000;
373
374	return sprintf(page, "%d\n", val);
375}
376
377static ssize_t queue_poll_delay_store(struct request_queue *q, const char *page,
378				size_t count)
379{
380	int err, val;
381
382	if (!q->mq_ops || !q->mq_ops->poll)
383		return -EINVAL;
384
385	err = kstrtoint(page, 10, &val);
386	if (err < 0)
387		return err;
388
389	if (val == -1)
390		q->poll_nsec = -1;
391	else
392		q->poll_nsec = val * 1000;
393
394	return count;
395}
396
397static ssize_t queue_poll_show(struct request_queue *q, char *page)
398{
399	return queue_var_show(test_bit(QUEUE_FLAG_POLL, &q->queue_flags), page);
400}
401
402static ssize_t queue_poll_store(struct request_queue *q, const char *page,
403				size_t count)
404{
405	unsigned long poll_on;
406	ssize_t ret;
407
408	if (!q->mq_ops || !q->mq_ops->poll)
409		return -EINVAL;
410
411	ret = queue_var_store(&poll_on, page, count);
412	if (ret < 0)
413		return ret;
414
415	if (poll_on)
416		blk_queue_flag_set(QUEUE_FLAG_POLL, q);
417	else
418		blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
419
420	return ret;
421}
422
423static ssize_t queue_wb_lat_show(struct request_queue *q, char *page)
424{
425	if (!q->rq_wb)
426		return -EINVAL;
427
428	return sprintf(page, "%llu\n", div_u64(q->rq_wb->min_lat_nsec, 1000));
429}
430
431static ssize_t queue_wb_lat_store(struct request_queue *q, const char *page,
432				  size_t count)
433{
434	struct rq_wb *rwb;
435	ssize_t ret;
436	s64 val;
437
438	ret = queue_var_store64(&val, page);
439	if (ret < 0)
440		return ret;
441	if (val < -1)
442		return -EINVAL;
443
444	rwb = q->rq_wb;
445	if (!rwb) {
446		ret = wbt_init(q);
447		if (ret)
448			return ret;
449	}
450
451	rwb = q->rq_wb;
452	if (val == -1)
453		rwb->min_lat_nsec = wbt_default_latency_nsec(q);
454	else if (val >= 0)
455		rwb->min_lat_nsec = val * 1000ULL;
456
457	if (rwb->enable_state == WBT_STATE_ON_DEFAULT)
458		rwb->enable_state = WBT_STATE_ON_MANUAL;
459
460	wbt_update_limits(rwb);
461	return count;
462}
463
464static ssize_t queue_wc_show(struct request_queue *q, char *page)
465{
466	if (test_bit(QUEUE_FLAG_WC, &q->queue_flags))
467		return sprintf(page, "write back\n");
468
469	return sprintf(page, "write through\n");
470}
471
472static ssize_t queue_wc_store(struct request_queue *q, const char *page,
473			      size_t count)
474{
475	int set = -1;
476
477	if (!strncmp(page, "write back", 10))
478		set = 1;
479	else if (!strncmp(page, "write through", 13) ||
480		 !strncmp(page, "none", 4))
481		set = 0;
482
483	if (set == -1)
484		return -EINVAL;
485
486	if (set)
487		blk_queue_flag_set(QUEUE_FLAG_WC, q);
488	else
489		blk_queue_flag_clear(QUEUE_FLAG_WC, q);
490
491	return count;
492}
493
494static ssize_t queue_dax_show(struct request_queue *q, char *page)
495{
496	return queue_var_show(blk_queue_dax(q), page);
497}
498
499static struct queue_sysfs_entry queue_requests_entry = {
500	.attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
501	.show = queue_requests_show,
502	.store = queue_requests_store,
503};
504
505static struct queue_sysfs_entry queue_ra_entry = {
506	.attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
507	.show = queue_ra_show,
508	.store = queue_ra_store,
509};
510
511static struct queue_sysfs_entry queue_max_sectors_entry = {
512	.attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
513	.show = queue_max_sectors_show,
514	.store = queue_max_sectors_store,
515};
516
517static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
518	.attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
519	.show = queue_max_hw_sectors_show,
520};
521
522static struct queue_sysfs_entry queue_max_segments_entry = {
523	.attr = {.name = "max_segments", .mode = S_IRUGO },
524	.show = queue_max_segments_show,
525};
526
527static struct queue_sysfs_entry queue_max_discard_segments_entry = {
528	.attr = {.name = "max_discard_segments", .mode = S_IRUGO },
529	.show = queue_max_discard_segments_show,
530};
531
532static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
533	.attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
534	.show = queue_max_integrity_segments_show,
535};
536
537static struct queue_sysfs_entry queue_max_segment_size_entry = {
538	.attr = {.name = "max_segment_size", .mode = S_IRUGO },
539	.show = queue_max_segment_size_show,
540};
541
542static struct queue_sysfs_entry queue_iosched_entry = {
543	.attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
544	.show = elv_iosched_show,
545	.store = elv_iosched_store,
546};
547
548static struct queue_sysfs_entry queue_hw_sector_size_entry = {
549	.attr = {.name = "hw_sector_size", .mode = S_IRUGO },
550	.show = queue_logical_block_size_show,
551};
552
553static struct queue_sysfs_entry queue_logical_block_size_entry = {
554	.attr = {.name = "logical_block_size", .mode = S_IRUGO },
555	.show = queue_logical_block_size_show,
556};
557
558static struct queue_sysfs_entry queue_physical_block_size_entry = {
559	.attr = {.name = "physical_block_size", .mode = S_IRUGO },
560	.show = queue_physical_block_size_show,
561};
562
563static struct queue_sysfs_entry queue_chunk_sectors_entry = {
564	.attr = {.name = "chunk_sectors", .mode = S_IRUGO },
565	.show = queue_chunk_sectors_show,
566};
567
568static struct queue_sysfs_entry queue_io_min_entry = {
569	.attr = {.name = "minimum_io_size", .mode = S_IRUGO },
570	.show = queue_io_min_show,
571};
572
573static struct queue_sysfs_entry queue_io_opt_entry = {
574	.attr = {.name = "optimal_io_size", .mode = S_IRUGO },
575	.show = queue_io_opt_show,
576};
577
578static struct queue_sysfs_entry queue_discard_granularity_entry = {
579	.attr = {.name = "discard_granularity", .mode = S_IRUGO },
580	.show = queue_discard_granularity_show,
581};
582
583static struct queue_sysfs_entry queue_discard_max_hw_entry = {
584	.attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
585	.show = queue_discard_max_hw_show,
586};
587
588static struct queue_sysfs_entry queue_discard_max_entry = {
589	.attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
590	.show = queue_discard_max_show,
591	.store = queue_discard_max_store,
592};
593
594static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
595	.attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
596	.show = queue_discard_zeroes_data_show,
597};
598
599static struct queue_sysfs_entry queue_write_same_max_entry = {
600	.attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
601	.show = queue_write_same_max_show,
602};
603
604static struct queue_sysfs_entry queue_write_zeroes_max_entry = {
605	.attr = {.name = "write_zeroes_max_bytes", .mode = S_IRUGO },
606	.show = queue_write_zeroes_max_show,
607};
608
609static struct queue_sysfs_entry queue_nonrot_entry = {
610	.attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
611	.show = queue_show_nonrot,
612	.store = queue_store_nonrot,
613};
614
615static struct queue_sysfs_entry queue_zoned_entry = {
616	.attr = {.name = "zoned", .mode = S_IRUGO },
617	.show = queue_zoned_show,
618};
619
620static struct queue_sysfs_entry queue_nomerges_entry = {
621	.attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
622	.show = queue_nomerges_show,
623	.store = queue_nomerges_store,
624};
625
626static struct queue_sysfs_entry queue_rq_affinity_entry = {
627	.attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
628	.show = queue_rq_affinity_show,
629	.store = queue_rq_affinity_store,
630};
631
632static struct queue_sysfs_entry queue_iostats_entry = {
633	.attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
634	.show = queue_show_iostats,
635	.store = queue_store_iostats,
636};
637
638static struct queue_sysfs_entry queue_random_entry = {
639	.attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
640	.show = queue_show_random,
641	.store = queue_store_random,
642};
643
644static struct queue_sysfs_entry queue_poll_entry = {
645	.attr = {.name = "io_poll", .mode = S_IRUGO | S_IWUSR },
646	.show = queue_poll_show,
647	.store = queue_poll_store,
648};
649
650static struct queue_sysfs_entry queue_poll_delay_entry = {
651	.attr = {.name = "io_poll_delay", .mode = S_IRUGO | S_IWUSR },
652	.show = queue_poll_delay_show,
653	.store = queue_poll_delay_store,
654};
655
656static struct queue_sysfs_entry queue_wc_entry = {
657	.attr = {.name = "write_cache", .mode = S_IRUGO | S_IWUSR },
658	.show = queue_wc_show,
659	.store = queue_wc_store,
660};
661
662static struct queue_sysfs_entry queue_dax_entry = {
663	.attr = {.name = "dax", .mode = S_IRUGO },
664	.show = queue_dax_show,
665};
666
667static struct queue_sysfs_entry queue_wb_lat_entry = {
668	.attr = {.name = "wbt_lat_usec", .mode = S_IRUGO | S_IWUSR },
669	.show = queue_wb_lat_show,
670	.store = queue_wb_lat_store,
671};
672
673#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
674static struct queue_sysfs_entry throtl_sample_time_entry = {
675	.attr = {.name = "throttle_sample_time", .mode = S_IRUGO | S_IWUSR },
676	.show = blk_throtl_sample_time_show,
677	.store = blk_throtl_sample_time_store,
678};
679#endif
680
681static struct attribute *default_attrs[] = {
682	&queue_requests_entry.attr,
683	&queue_ra_entry.attr,
684	&queue_max_hw_sectors_entry.attr,
685	&queue_max_sectors_entry.attr,
686	&queue_max_segments_entry.attr,
687	&queue_max_discard_segments_entry.attr,
688	&queue_max_integrity_segments_entry.attr,
689	&queue_max_segment_size_entry.attr,
690	&queue_iosched_entry.attr,
691	&queue_hw_sector_size_entry.attr,
692	&queue_logical_block_size_entry.attr,
693	&queue_physical_block_size_entry.attr,
694	&queue_chunk_sectors_entry.attr,
695	&queue_io_min_entry.attr,
696	&queue_io_opt_entry.attr,
697	&queue_discard_granularity_entry.attr,
698	&queue_discard_max_entry.attr,
699	&queue_discard_max_hw_entry.attr,
700	&queue_discard_zeroes_data_entry.attr,
701	&queue_write_same_max_entry.attr,
702	&queue_write_zeroes_max_entry.attr,
703	&queue_nonrot_entry.attr,
704	&queue_zoned_entry.attr,
705	&queue_nomerges_entry.attr,
706	&queue_rq_affinity_entry.attr,
707	&queue_iostats_entry.attr,
708	&queue_random_entry.attr,
709	&queue_poll_entry.attr,
710	&queue_wc_entry.attr,
711	&queue_dax_entry.attr,
712	&queue_wb_lat_entry.attr,
713	&queue_poll_delay_entry.attr,
714#ifdef CONFIG_BLK_DEV_THROTTLING_LOW
715	&throtl_sample_time_entry.attr,
716#endif
717	NULL,
718};
719
720#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
721
722static ssize_t
723queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
724{
725	struct queue_sysfs_entry *entry = to_queue(attr);
726	struct request_queue *q =
727		container_of(kobj, struct request_queue, kobj);
728	ssize_t res;
729
730	if (!entry->show)
731		return -EIO;
732	mutex_lock(&q->sysfs_lock);
733	if (blk_queue_dying(q)) {
734		mutex_unlock(&q->sysfs_lock);
735		return -ENOENT;
736	}
737	res = entry->show(q, page);
738	mutex_unlock(&q->sysfs_lock);
739	return res;
740}
741
742static ssize_t
743queue_attr_store(struct kobject *kobj, struct attribute *attr,
744		    const char *page, size_t length)
745{
746	struct queue_sysfs_entry *entry = to_queue(attr);
747	struct request_queue *q;
748	ssize_t res;
749
750	if (!entry->store)
751		return -EIO;
752
753	q = container_of(kobj, struct request_queue, kobj);
754	mutex_lock(&q->sysfs_lock);
755	if (blk_queue_dying(q)) {
756		mutex_unlock(&q->sysfs_lock);
757		return -ENOENT;
758	}
759	res = entry->store(q, page, length);
760	mutex_unlock(&q->sysfs_lock);
761	return res;
762}
763
764static void blk_free_queue_rcu(struct rcu_head *rcu_head)
765{
766	struct request_queue *q = container_of(rcu_head, struct request_queue,
767					       rcu_head);
768	kmem_cache_free(blk_requestq_cachep, q);
769}
770
771/**
772 * __blk_release_queue - release a request queue when it is no longer needed
773 * @work: pointer to the release_work member of the request queue to be released
774 *
775 * Description:
776 *     blk_release_queue is the counterpart of blk_init_queue(). It should be
777 *     called when a request queue is being released; typically when a block
778 *     device is being de-registered. Its primary task it to free the queue
779 *     itself.
 
780 *
781 * Notes:
782 *     The low level driver must have finished any outstanding requests first
783 *     via blk_cleanup_queue().
784 *
785 *     Although blk_release_queue() may be called with preemption disabled,
786 *     __blk_release_queue() may sleep.
787 */
788static void __blk_release_queue(struct work_struct *work)
789{
790	struct request_queue *q = container_of(work, typeof(*q), release_work);
 
791
792	if (test_bit(QUEUE_FLAG_POLL_STATS, &q->queue_flags))
793		blk_stat_remove_callback(q, q->poll_cb);
794	blk_stat_free_callback(q->poll_cb);
795
796	blk_free_queue_stats(q->stats);
797
798	blk_exit_rl(q, &q->root_rl);
 
 
 
 
 
 
 
799
800	if (q->queue_tags)
801		__blk_queue_free_tags(q);
802
803	if (!q->mq_ops) {
804		if (q->exit_rq_fn)
805			q->exit_rq_fn(q, q->fq->flush_rq);
806		blk_free_flush_queue(q->fq);
807	} else {
808		blk_mq_release(q);
809	}
810
811	blk_trace_shutdown(q);
812
813	if (q->mq_ops)
814		blk_mq_debugfs_unregister(q);
815
816	if (q->bio_split)
817		bioset_free(q->bio_split);
818
819	ida_simple_remove(&blk_queue_ida, q->id);
820	call_rcu(&q->rcu_head, blk_free_queue_rcu);
821}
822
823static void blk_release_queue(struct kobject *kobj)
824{
825	struct request_queue *q =
826		container_of(kobj, struct request_queue, kobj);
827
828	INIT_WORK(&q->release_work, __blk_release_queue);
829	schedule_work(&q->release_work);
830}
831
832static const struct sysfs_ops queue_sysfs_ops = {
833	.show	= queue_attr_show,
834	.store	= queue_attr_store,
835};
836
837struct kobj_type blk_queue_ktype = {
838	.sysfs_ops	= &queue_sysfs_ops,
839	.default_attrs	= default_attrs,
840	.release	= blk_release_queue,
841};
842
843/**
844 * blk_register_queue - register a block layer queue with sysfs
845 * @disk: Disk of which the request queue should be registered with sysfs.
846 */
847int blk_register_queue(struct gendisk *disk)
848{
849	int ret;
850	struct device *dev = disk_to_dev(disk);
851	struct request_queue *q = disk->queue;
852
853	if (WARN_ON(!q))
854		return -ENXIO;
855
856	WARN_ONCE(test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags),
857		  "%s is registering an already registered queue\n",
858		  kobject_name(&dev->kobj));
859	queue_flag_set_unlocked(QUEUE_FLAG_REGISTERED, q);
860
861	/*
862	 * SCSI probing may synchronously create and destroy a lot of
863	 * request_queues for non-existent devices.  Shutting down a fully
864	 * functional queue takes measureable wallclock time as RCU grace
865	 * periods are involved.  To avoid excessive latency in these
866	 * cases, a request_queue starts out in a degraded mode which is
867	 * faster to shut down and is made fully functional here as
868	 * request_queues for non-existent devices never get registered.
869	 */
870	if (!blk_queue_init_done(q)) {
871		queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
872		percpu_ref_switch_to_percpu(&q->q_usage_counter);
873		blk_queue_bypass_end(q);
874	}
875
876	ret = blk_trace_init_sysfs(dev);
877	if (ret)
878		return ret;
879
880	/* Prevent changes through sysfs until registration is completed. */
881	mutex_lock(&q->sysfs_lock);
882
883	ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
884	if (ret < 0) {
885		blk_trace_remove_sysfs(dev);
886		goto unlock;
887	}
888
889	if (q->mq_ops) {
890		__blk_mq_register_dev(dev, q);
891		blk_mq_debugfs_register(q);
892	}
893
894	kobject_uevent(&q->kobj, KOBJ_ADD);
895
896	wbt_enable_default(q);
 
897
898	blk_throtl_register_queue(q);
 
899
900	if (q->request_fn || (q->mq_ops && q->elevator)) {
901		ret = elv_register_queue(q);
902		if (ret) {
903			mutex_unlock(&q->sysfs_lock);
904			kobject_uevent(&q->kobj, KOBJ_REMOVE);
905			kobject_del(&q->kobj);
906			blk_trace_remove_sysfs(dev);
907			kobject_put(&dev->kobj);
908			return ret;
909		}
910	}
911	ret = 0;
912unlock:
913	mutex_unlock(&q->sysfs_lock);
914	return ret;
915}
916EXPORT_SYMBOL_GPL(blk_register_queue);
917
918/**
919 * blk_unregister_queue - counterpart of blk_register_queue()
920 * @disk: Disk of which the request queue should be unregistered from sysfs.
921 *
922 * Note: the caller is responsible for guaranteeing that this function is called
923 * after blk_register_queue() has finished.
924 */
925void blk_unregister_queue(struct gendisk *disk)
926{
927	struct request_queue *q = disk->queue;
928
929	if (WARN_ON(!q))
930		return;
931
932	/* Return early if disk->queue was never registered. */
933	if (!test_bit(QUEUE_FLAG_REGISTERED, &q->queue_flags))
934		return;
935
936	/*
937	 * Since sysfs_remove_dir() prevents adding new directory entries
938	 * before removal of existing entries starts, protect against
939	 * concurrent elv_iosched_store() calls.
940	 */
941	mutex_lock(&q->sysfs_lock);
942
943	blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
944
945	/*
946	 * Remove the sysfs attributes before unregistering the queue data
947	 * structures that can be modified through sysfs.
948	 */
949	if (q->mq_ops)
950		blk_mq_unregister_dev(disk_to_dev(disk), q);
951	mutex_unlock(&q->sysfs_lock);
952
953	kobject_uevent(&q->kobj, KOBJ_REMOVE);
954	kobject_del(&q->kobj);
955	blk_trace_remove_sysfs(disk_to_dev(disk));
956
957	wbt_exit(q);
958
959	mutex_lock(&q->sysfs_lock);
960	if (q->request_fn || (q->mq_ops && q->elevator))
961		elv_unregister_queue(q);
962	mutex_unlock(&q->sysfs_lock);
963
964	kobject_put(&disk_to_dev(disk)->kobj);
965}