xref: /linux/block/blk-sysfs.c (revision 6e9a12f85a7567bb9a41d5230468886bd6a27b20)
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 
23 struct queue_sysfs_entry {
24 	struct attribute attr;
25 	ssize_t (*show)(struct gendisk *disk, char *page);
26 	ssize_t (*show_limit)(struct gendisk *disk, char *page);
27 
28 	ssize_t (*store)(struct gendisk *disk, const char *page, size_t count);
29 	int (*store_limit)(struct gendisk *disk, const char *page,
30 			size_t count, struct queue_limits *lim);
31 };
32 
33 static ssize_t
34 queue_var_show(unsigned long var, char *page)
35 {
36 	return sysfs_emit(page, "%lu\n", var);
37 }
38 
39 static ssize_t
40 queue_var_store(unsigned long *var, const char *page, size_t count)
41 {
42 	int err;
43 	unsigned long v;
44 
45 	err = kstrtoul(page, 10, &v);
46 	if (err || v > UINT_MAX)
47 		return -EINVAL;
48 
49 	*var = v;
50 
51 	return count;
52 }
53 
54 static ssize_t queue_requests_show(struct gendisk *disk, char *page)
55 {
56 	ssize_t ret;
57 
58 	mutex_lock(&disk->queue->elevator_lock);
59 	ret = queue_var_show(disk->queue->nr_requests, page);
60 	mutex_unlock(&disk->queue->elevator_lock);
61 	return ret;
62 }
63 
64 static ssize_t
65 queue_requests_store(struct gendisk *disk, const char *page, size_t count)
66 {
67 	unsigned long nr;
68 	int ret, err;
69 	unsigned int memflags;
70 	struct request_queue *q = disk->queue;
71 
72 	if (!queue_is_mq(q))
73 		return -EINVAL;
74 
75 	ret = queue_var_store(&nr, page, count);
76 	if (ret < 0)
77 		return ret;
78 
79 	memflags = blk_mq_freeze_queue(q);
80 	mutex_lock(&q->elevator_lock);
81 	if (nr < BLKDEV_MIN_RQ)
82 		nr = BLKDEV_MIN_RQ;
83 
84 	err = blk_mq_update_nr_requests(disk->queue, nr);
85 	if (err)
86 		ret = err;
87 	mutex_unlock(&q->elevator_lock);
88 	blk_mq_unfreeze_queue(q, memflags);
89 	return ret;
90 }
91 
92 static ssize_t queue_ra_show(struct gendisk *disk, char *page)
93 {
94 	ssize_t ret;
95 
96 	mutex_lock(&disk->queue->limits_lock);
97 	ret = queue_var_show(disk->bdi->ra_pages << (PAGE_SHIFT - 10), page);
98 	mutex_unlock(&disk->queue->limits_lock);
99 
100 	return ret;
101 }
102 
103 static ssize_t
104 queue_ra_store(struct gendisk *disk, const char *page, size_t count)
105 {
106 	unsigned long ra_kb;
107 	ssize_t ret;
108 	unsigned int memflags;
109 	struct request_queue *q = disk->queue;
110 
111 	ret = queue_var_store(&ra_kb, page, count);
112 	if (ret < 0)
113 		return ret;
114 	/*
115 	 * ->ra_pages is protected by ->limits_lock because it is usually
116 	 * calculated from the queue limits by queue_limits_commit_update.
117 	 */
118 	mutex_lock(&q->limits_lock);
119 	memflags = blk_mq_freeze_queue(q);
120 	disk->bdi->ra_pages = ra_kb >> (PAGE_SHIFT - 10);
121 	mutex_unlock(&q->limits_lock);
122 	blk_mq_unfreeze_queue(q, memflags);
123 
124 	return ret;
125 }
126 
127 #define QUEUE_SYSFS_LIMIT_SHOW(_field)					\
128 static ssize_t queue_##_field##_show(struct gendisk *disk, char *page)	\
129 {									\
130 	return queue_var_show(disk->queue->limits._field, page);	\
131 }
132 
133 QUEUE_SYSFS_LIMIT_SHOW(max_segments)
134 QUEUE_SYSFS_LIMIT_SHOW(max_discard_segments)
135 QUEUE_SYSFS_LIMIT_SHOW(max_integrity_segments)
136 QUEUE_SYSFS_LIMIT_SHOW(max_segment_size)
137 QUEUE_SYSFS_LIMIT_SHOW(max_write_streams)
138 QUEUE_SYSFS_LIMIT_SHOW(write_stream_granularity)
139 QUEUE_SYSFS_LIMIT_SHOW(logical_block_size)
140 QUEUE_SYSFS_LIMIT_SHOW(physical_block_size)
141 QUEUE_SYSFS_LIMIT_SHOW(chunk_sectors)
142 QUEUE_SYSFS_LIMIT_SHOW(io_min)
143 QUEUE_SYSFS_LIMIT_SHOW(io_opt)
144 QUEUE_SYSFS_LIMIT_SHOW(discard_granularity)
145 QUEUE_SYSFS_LIMIT_SHOW(zone_write_granularity)
146 QUEUE_SYSFS_LIMIT_SHOW(virt_boundary_mask)
147 QUEUE_SYSFS_LIMIT_SHOW(dma_alignment)
148 QUEUE_SYSFS_LIMIT_SHOW(max_open_zones)
149 QUEUE_SYSFS_LIMIT_SHOW(max_active_zones)
150 QUEUE_SYSFS_LIMIT_SHOW(atomic_write_unit_min)
151 QUEUE_SYSFS_LIMIT_SHOW(atomic_write_unit_max)
152 
153 #define QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(_field)			\
154 static ssize_t queue_##_field##_show(struct gendisk *disk, char *page)	\
155 {									\
156 	return sysfs_emit(page, "%llu\n",				\
157 		(unsigned long long)disk->queue->limits._field <<	\
158 			SECTOR_SHIFT);					\
159 }
160 
161 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_discard_sectors)
162 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_hw_discard_sectors)
163 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_write_zeroes_sectors)
164 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_hw_wzeroes_unmap_sectors)
165 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_wzeroes_unmap_sectors)
166 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(atomic_write_max_sectors)
167 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(atomic_write_boundary_sectors)
168 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_BYTES(max_zone_append_sectors)
169 
170 #define QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(_field)			\
171 static ssize_t queue_##_field##_show(struct gendisk *disk, char *page)	\
172 {									\
173 	return queue_var_show(disk->queue->limits._field >> 1, page);	\
174 }
175 
176 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(max_sectors)
177 QUEUE_SYSFS_LIMIT_SHOW_SECTORS_TO_KB(max_hw_sectors)
178 
179 #define QUEUE_SYSFS_SHOW_CONST(_name, _val)				\
180 static ssize_t queue_##_name##_show(struct gendisk *disk, char *page)	\
181 {									\
182 	return sysfs_emit(page, "%d\n", _val);				\
183 }
184 
185 /* deprecated fields */
186 QUEUE_SYSFS_SHOW_CONST(discard_zeroes_data, 0)
187 QUEUE_SYSFS_SHOW_CONST(write_same_max, 0)
188 QUEUE_SYSFS_SHOW_CONST(poll_delay, -1)
189 
190 static int queue_max_discard_sectors_store(struct gendisk *disk,
191 		const char *page, size_t count, struct queue_limits *lim)
192 {
193 	unsigned long max_discard_bytes;
194 	ssize_t ret;
195 
196 	ret = queue_var_store(&max_discard_bytes, page, count);
197 	if (ret < 0)
198 		return ret;
199 
200 	if (max_discard_bytes & (disk->queue->limits.discard_granularity - 1))
201 		return -EINVAL;
202 
203 	if ((max_discard_bytes >> SECTOR_SHIFT) > UINT_MAX)
204 		return -EINVAL;
205 
206 	lim->max_user_discard_sectors = max_discard_bytes >> SECTOR_SHIFT;
207 	return 0;
208 }
209 
210 static int queue_max_wzeroes_unmap_sectors_store(struct gendisk *disk,
211 		const char *page, size_t count, struct queue_limits *lim)
212 {
213 	unsigned long max_zeroes_bytes, max_hw_zeroes_bytes;
214 	ssize_t ret;
215 
216 	ret = queue_var_store(&max_zeroes_bytes, page, count);
217 	if (ret < 0)
218 		return ret;
219 
220 	max_hw_zeroes_bytes = lim->max_hw_wzeroes_unmap_sectors << SECTOR_SHIFT;
221 	if (max_zeroes_bytes != 0 && max_zeroes_bytes != max_hw_zeroes_bytes)
222 		return -EINVAL;
223 
224 	lim->max_user_wzeroes_unmap_sectors = max_zeroes_bytes >> SECTOR_SHIFT;
225 	return 0;
226 }
227 
228 static int
229 queue_max_sectors_store(struct gendisk *disk, const char *page, size_t count,
230 		struct queue_limits *lim)
231 {
232 	unsigned long max_sectors_kb;
233 	ssize_t ret;
234 
235 	ret = queue_var_store(&max_sectors_kb, page, count);
236 	if (ret < 0)
237 		return ret;
238 
239 	lim->max_user_sectors = max_sectors_kb << 1;
240 	return 0;
241 }
242 
243 static ssize_t queue_feature_store(struct gendisk *disk, const char *page,
244 		size_t count, struct queue_limits *lim, blk_features_t feature)
245 {
246 	unsigned long val;
247 	ssize_t ret;
248 
249 	ret = queue_var_store(&val, page, count);
250 	if (ret < 0)
251 		return ret;
252 
253 	if (val)
254 		lim->features |= feature;
255 	else
256 		lim->features &= ~feature;
257 	return 0;
258 }
259 
260 #define QUEUE_SYSFS_FEATURE(_name, _feature)				\
261 static ssize_t queue_##_name##_show(struct gendisk *disk, char *page)	\
262 {									\
263 	return sysfs_emit(page, "%u\n",					\
264 		!!(disk->queue->limits.features & _feature));		\
265 }									\
266 static int queue_##_name##_store(struct gendisk *disk,			\
267 		const char *page, size_t count, struct queue_limits *lim) \
268 {									\
269 	return queue_feature_store(disk, page, count, lim, _feature);	\
270 }
271 
272 QUEUE_SYSFS_FEATURE(rotational, BLK_FEAT_ROTATIONAL)
273 QUEUE_SYSFS_FEATURE(add_random, BLK_FEAT_ADD_RANDOM)
274 QUEUE_SYSFS_FEATURE(iostats, BLK_FEAT_IO_STAT)
275 QUEUE_SYSFS_FEATURE(stable_writes, BLK_FEAT_STABLE_WRITES);
276 
277 #define QUEUE_SYSFS_FEATURE_SHOW(_name, _feature)			\
278 static ssize_t queue_##_name##_show(struct gendisk *disk, char *page)	\
279 {									\
280 	return sysfs_emit(page, "%u\n",					\
281 		!!(disk->queue->limits.features & _feature));		\
282 }
283 
284 QUEUE_SYSFS_FEATURE_SHOW(fua, BLK_FEAT_FUA);
285 QUEUE_SYSFS_FEATURE_SHOW(dax, BLK_FEAT_DAX);
286 
287 static ssize_t queue_poll_show(struct gendisk *disk, char *page)
288 {
289 	if (queue_is_mq(disk->queue))
290 		return sysfs_emit(page, "%u\n", blk_mq_can_poll(disk->queue));
291 
292 	return sysfs_emit(page, "%u\n",
293 			!!(disk->queue->limits.features & BLK_FEAT_POLL));
294 }
295 
296 static ssize_t queue_zoned_show(struct gendisk *disk, char *page)
297 {
298 	if (blk_queue_is_zoned(disk->queue))
299 		return sysfs_emit(page, "host-managed\n");
300 	return sysfs_emit(page, "none\n");
301 }
302 
303 static ssize_t queue_nr_zones_show(struct gendisk *disk, char *page)
304 {
305 	return queue_var_show(disk_nr_zones(disk), page);
306 }
307 
308 static ssize_t queue_iostats_passthrough_show(struct gendisk *disk, char *page)
309 {
310 	return queue_var_show(!!blk_queue_passthrough_stat(disk->queue), page);
311 }
312 
313 static int queue_iostats_passthrough_store(struct gendisk *disk,
314 		const char *page, size_t count, struct queue_limits *lim)
315 {
316 	unsigned long ios;
317 	ssize_t ret;
318 
319 	ret = queue_var_store(&ios, page, count);
320 	if (ret < 0)
321 		return ret;
322 
323 	if (ios)
324 		lim->flags |= BLK_FLAG_IOSTATS_PASSTHROUGH;
325 	else
326 		lim->flags &= ~BLK_FLAG_IOSTATS_PASSTHROUGH;
327 	return 0;
328 }
329 
330 static ssize_t queue_nomerges_show(struct gendisk *disk, char *page)
331 {
332 	return queue_var_show((blk_queue_nomerges(disk->queue) << 1) |
333 			       blk_queue_noxmerges(disk->queue), page);
334 }
335 
336 static ssize_t queue_nomerges_store(struct gendisk *disk, const char *page,
337 				    size_t count)
338 {
339 	unsigned long nm;
340 	unsigned int memflags;
341 	struct request_queue *q = disk->queue;
342 	ssize_t ret = queue_var_store(&nm, page, count);
343 
344 	if (ret < 0)
345 		return ret;
346 
347 	memflags = blk_mq_freeze_queue(q);
348 	blk_queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
349 	blk_queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
350 	if (nm == 2)
351 		blk_queue_flag_set(QUEUE_FLAG_NOMERGES, q);
352 	else if (nm)
353 		blk_queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
354 	blk_mq_unfreeze_queue(q, memflags);
355 
356 	return ret;
357 }
358 
359 static ssize_t queue_rq_affinity_show(struct gendisk *disk, char *page)
360 {
361 	bool set = test_bit(QUEUE_FLAG_SAME_COMP, &disk->queue->queue_flags);
362 	bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &disk->queue->queue_flags);
363 
364 	return queue_var_show(set << force, page);
365 }
366 
367 static ssize_t
368 queue_rq_affinity_store(struct gendisk *disk, const char *page, size_t count)
369 {
370 	ssize_t ret = -EINVAL;
371 #ifdef CONFIG_SMP
372 	struct request_queue *q = disk->queue;
373 	unsigned long val;
374 	unsigned int memflags;
375 
376 	ret = queue_var_store(&val, page, count);
377 	if (ret < 0)
378 		return ret;
379 
380 	/*
381 	 * Here we update two queue flags each using atomic bitops, although
382 	 * updating two flags isn't atomic it should be harmless as those flags
383 	 * are accessed individually using atomic test_bit operation. So we
384 	 * don't grab any lock while updating these flags.
385 	 */
386 	memflags = blk_mq_freeze_queue(q);
387 	if (val == 2) {
388 		blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
389 		blk_queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
390 	} else if (val == 1) {
391 		blk_queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
392 		blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
393 	} else if (val == 0) {
394 		blk_queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
395 		blk_queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
396 	}
397 	blk_mq_unfreeze_queue(q, memflags);
398 #endif
399 	return ret;
400 }
401 
402 static ssize_t queue_poll_delay_store(struct gendisk *disk, const char *page,
403 				size_t count)
404 {
405 	return count;
406 }
407 
408 static ssize_t queue_poll_store(struct gendisk *disk, const char *page,
409 				size_t count)
410 {
411 	unsigned int memflags;
412 	ssize_t ret = count;
413 	struct request_queue *q = disk->queue;
414 
415 	memflags = blk_mq_freeze_queue(q);
416 	if (!(q->limits.features & BLK_FEAT_POLL)) {
417 		ret = -EINVAL;
418 		goto out;
419 	}
420 
421 	pr_info_ratelimited("writes to the poll attribute are ignored.\n");
422 	pr_info_ratelimited("please use driver specific parameters instead.\n");
423 out:
424 	blk_mq_unfreeze_queue(q, memflags);
425 	return ret;
426 }
427 
428 static ssize_t queue_io_timeout_show(struct gendisk *disk, char *page)
429 {
430 	return sysfs_emit(page, "%u\n",
431 			jiffies_to_msecs(READ_ONCE(disk->queue->rq_timeout)));
432 }
433 
434 static ssize_t queue_io_timeout_store(struct gendisk *disk, const char *page,
435 				  size_t count)
436 {
437 	unsigned int val, memflags;
438 	int err;
439 	struct request_queue *q = disk->queue;
440 
441 	err = kstrtou32(page, 10, &val);
442 	if (err || val == 0)
443 		return -EINVAL;
444 
445 	memflags = blk_mq_freeze_queue(q);
446 	blk_queue_rq_timeout(q, msecs_to_jiffies(val));
447 	blk_mq_unfreeze_queue(q, memflags);
448 
449 	return count;
450 }
451 
452 static ssize_t queue_wc_show(struct gendisk *disk, char *page)
453 {
454 	if (blk_queue_write_cache(disk->queue))
455 		return sysfs_emit(page, "write back\n");
456 	return sysfs_emit(page, "write through\n");
457 }
458 
459 static int queue_wc_store(struct gendisk *disk, const char *page,
460 		size_t count, struct queue_limits *lim)
461 {
462 	bool disable;
463 
464 	if (!strncmp(page, "write back", 10)) {
465 		disable = false;
466 	} else if (!strncmp(page, "write through", 13) ||
467 		   !strncmp(page, "none", 4)) {
468 		disable = true;
469 	} else {
470 		return -EINVAL;
471 	}
472 
473 	if (disable)
474 		lim->flags |= BLK_FLAG_WRITE_CACHE_DISABLED;
475 	else
476 		lim->flags &= ~BLK_FLAG_WRITE_CACHE_DISABLED;
477 	return 0;
478 }
479 
480 #define QUEUE_RO_ENTRY(_prefix, _name)			\
481 static struct queue_sysfs_entry _prefix##_entry = {	\
482 	.attr	= { .name = _name, .mode = 0444 },	\
483 	.show	= _prefix##_show,			\
484 };
485 
486 #define QUEUE_RW_ENTRY(_prefix, _name)			\
487 static struct queue_sysfs_entry _prefix##_entry = {	\
488 	.attr	= { .name = _name, .mode = 0644 },	\
489 	.show	= _prefix##_show,			\
490 	.store	= _prefix##_store,			\
491 };
492 
493 #define QUEUE_LIM_RO_ENTRY(_prefix, _name)			\
494 static struct queue_sysfs_entry _prefix##_entry = {	\
495 	.attr		= { .name = _name, .mode = 0444 },	\
496 	.show_limit	= _prefix##_show,			\
497 }
498 
499 #define QUEUE_LIM_RW_ENTRY(_prefix, _name)			\
500 static struct queue_sysfs_entry _prefix##_entry = {	\
501 	.attr		= { .name = _name, .mode = 0644 },	\
502 	.show_limit	= _prefix##_show,			\
503 	.store_limit	= _prefix##_store,			\
504 }
505 
506 QUEUE_RW_ENTRY(queue_requests, "nr_requests");
507 QUEUE_RW_ENTRY(queue_ra, "read_ahead_kb");
508 QUEUE_LIM_RW_ENTRY(queue_max_sectors, "max_sectors_kb");
509 QUEUE_LIM_RO_ENTRY(queue_max_hw_sectors, "max_hw_sectors_kb");
510 QUEUE_LIM_RO_ENTRY(queue_max_segments, "max_segments");
511 QUEUE_LIM_RO_ENTRY(queue_max_integrity_segments, "max_integrity_segments");
512 QUEUE_LIM_RO_ENTRY(queue_max_segment_size, "max_segment_size");
513 QUEUE_LIM_RO_ENTRY(queue_max_write_streams, "max_write_streams");
514 QUEUE_LIM_RO_ENTRY(queue_write_stream_granularity, "write_stream_granularity");
515 QUEUE_RW_ENTRY(elv_iosched, "scheduler");
516 
517 QUEUE_LIM_RO_ENTRY(queue_logical_block_size, "logical_block_size");
518 QUEUE_LIM_RO_ENTRY(queue_physical_block_size, "physical_block_size");
519 QUEUE_LIM_RO_ENTRY(queue_chunk_sectors, "chunk_sectors");
520 QUEUE_LIM_RO_ENTRY(queue_io_min, "minimum_io_size");
521 QUEUE_LIM_RO_ENTRY(queue_io_opt, "optimal_io_size");
522 
523 QUEUE_LIM_RO_ENTRY(queue_max_discard_segments, "max_discard_segments");
524 QUEUE_LIM_RO_ENTRY(queue_discard_granularity, "discard_granularity");
525 QUEUE_LIM_RO_ENTRY(queue_max_hw_discard_sectors, "discard_max_hw_bytes");
526 QUEUE_LIM_RW_ENTRY(queue_max_discard_sectors, "discard_max_bytes");
527 QUEUE_RO_ENTRY(queue_discard_zeroes_data, "discard_zeroes_data");
528 
529 QUEUE_LIM_RO_ENTRY(queue_atomic_write_max_sectors, "atomic_write_max_bytes");
530 QUEUE_LIM_RO_ENTRY(queue_atomic_write_boundary_sectors,
531 		"atomic_write_boundary_bytes");
532 QUEUE_LIM_RO_ENTRY(queue_atomic_write_unit_max, "atomic_write_unit_max_bytes");
533 QUEUE_LIM_RO_ENTRY(queue_atomic_write_unit_min, "atomic_write_unit_min_bytes");
534 
535 QUEUE_RO_ENTRY(queue_write_same_max, "write_same_max_bytes");
536 QUEUE_LIM_RO_ENTRY(queue_max_write_zeroes_sectors, "write_zeroes_max_bytes");
537 QUEUE_LIM_RO_ENTRY(queue_max_hw_wzeroes_unmap_sectors,
538 		"write_zeroes_unmap_max_hw_bytes");
539 QUEUE_LIM_RW_ENTRY(queue_max_wzeroes_unmap_sectors,
540 		"write_zeroes_unmap_max_bytes");
541 QUEUE_LIM_RO_ENTRY(queue_max_zone_append_sectors, "zone_append_max_bytes");
542 QUEUE_LIM_RO_ENTRY(queue_zone_write_granularity, "zone_write_granularity");
543 
544 QUEUE_LIM_RO_ENTRY(queue_zoned, "zoned");
545 QUEUE_RO_ENTRY(queue_nr_zones, "nr_zones");
546 QUEUE_LIM_RO_ENTRY(queue_max_open_zones, "max_open_zones");
547 QUEUE_LIM_RO_ENTRY(queue_max_active_zones, "max_active_zones");
548 
549 QUEUE_RW_ENTRY(queue_nomerges, "nomerges");
550 QUEUE_LIM_RW_ENTRY(queue_iostats_passthrough, "iostats_passthrough");
551 QUEUE_RW_ENTRY(queue_rq_affinity, "rq_affinity");
552 QUEUE_RW_ENTRY(queue_poll, "io_poll");
553 QUEUE_RW_ENTRY(queue_poll_delay, "io_poll_delay");
554 QUEUE_LIM_RW_ENTRY(queue_wc, "write_cache");
555 QUEUE_LIM_RO_ENTRY(queue_fua, "fua");
556 QUEUE_LIM_RO_ENTRY(queue_dax, "dax");
557 QUEUE_RW_ENTRY(queue_io_timeout, "io_timeout");
558 QUEUE_LIM_RO_ENTRY(queue_virt_boundary_mask, "virt_boundary_mask");
559 QUEUE_LIM_RO_ENTRY(queue_dma_alignment, "dma_alignment");
560 
561 /* legacy alias for logical_block_size: */
562 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
563 	.attr		= {.name = "hw_sector_size", .mode = 0444 },
564 	.show_limit	= queue_logical_block_size_show,
565 };
566 
567 QUEUE_LIM_RW_ENTRY(queue_rotational, "rotational");
568 QUEUE_LIM_RW_ENTRY(queue_iostats, "iostats");
569 QUEUE_LIM_RW_ENTRY(queue_add_random, "add_random");
570 QUEUE_LIM_RW_ENTRY(queue_stable_writes, "stable_writes");
571 
572 #ifdef CONFIG_BLK_WBT
573 static ssize_t queue_var_store64(s64 *var, const char *page)
574 {
575 	int err;
576 	s64 v;
577 
578 	err = kstrtos64(page, 10, &v);
579 	if (err < 0)
580 		return err;
581 
582 	*var = v;
583 	return 0;
584 }
585 
586 static ssize_t queue_wb_lat_show(struct gendisk *disk, char *page)
587 {
588 	ssize_t ret;
589 	struct request_queue *q = disk->queue;
590 
591 	mutex_lock(&disk->rqos_state_mutex);
592 	if (!wbt_rq_qos(q)) {
593 		ret = -EINVAL;
594 		goto out;
595 	}
596 
597 	if (wbt_disabled(q)) {
598 		ret = sysfs_emit(page, "0\n");
599 		goto out;
600 	}
601 
602 	ret = sysfs_emit(page, "%llu\n", div_u64(wbt_get_min_lat(q), 1000));
603 out:
604 	mutex_unlock(&disk->rqos_state_mutex);
605 	return ret;
606 }
607 
608 static ssize_t queue_wb_lat_store(struct gendisk *disk, const char *page,
609 				  size_t count)
610 {
611 	struct request_queue *q = disk->queue;
612 	struct rq_qos *rqos;
613 	ssize_t ret;
614 	s64 val;
615 	unsigned int memflags;
616 
617 	ret = queue_var_store64(&val, page);
618 	if (ret < 0)
619 		return ret;
620 	if (val < -1)
621 		return -EINVAL;
622 
623 	memflags = blk_mq_freeze_queue(q);
624 
625 	rqos = wbt_rq_qos(q);
626 	if (!rqos) {
627 		ret = wbt_init(disk);
628 		if (ret)
629 			goto out;
630 	}
631 
632 	ret = count;
633 	if (val == -1)
634 		val = wbt_default_latency_nsec(q);
635 	else if (val >= 0)
636 		val *= 1000ULL;
637 
638 	if (wbt_get_min_lat(q) == val)
639 		goto out;
640 
641 	/*
642 	 * Ensure that the queue is idled, in case the latency update
643 	 * ends up either enabling or disabling wbt completely. We can't
644 	 * have IO inflight if that happens.
645 	 */
646 	blk_mq_quiesce_queue(q);
647 
648 	mutex_lock(&disk->rqos_state_mutex);
649 	wbt_set_min_lat(q, val);
650 	mutex_unlock(&disk->rqos_state_mutex);
651 
652 	blk_mq_unquiesce_queue(q);
653 out:
654 	blk_mq_unfreeze_queue(q, memflags);
655 
656 	return ret;
657 }
658 
659 QUEUE_RW_ENTRY(queue_wb_lat, "wbt_lat_usec");
660 #endif
661 
662 /* Common attributes for bio-based and request-based queues. */
663 static struct attribute *queue_attrs[] = {
664 	/*
665 	 * Attributes which are protected with q->limits_lock.
666 	 */
667 	&queue_max_hw_sectors_entry.attr,
668 	&queue_max_sectors_entry.attr,
669 	&queue_max_segments_entry.attr,
670 	&queue_max_discard_segments_entry.attr,
671 	&queue_max_integrity_segments_entry.attr,
672 	&queue_max_segment_size_entry.attr,
673 	&queue_max_write_streams_entry.attr,
674 	&queue_write_stream_granularity_entry.attr,
675 	&queue_hw_sector_size_entry.attr,
676 	&queue_logical_block_size_entry.attr,
677 	&queue_physical_block_size_entry.attr,
678 	&queue_chunk_sectors_entry.attr,
679 	&queue_io_min_entry.attr,
680 	&queue_io_opt_entry.attr,
681 	&queue_discard_granularity_entry.attr,
682 	&queue_max_discard_sectors_entry.attr,
683 	&queue_max_hw_discard_sectors_entry.attr,
684 	&queue_atomic_write_max_sectors_entry.attr,
685 	&queue_atomic_write_boundary_sectors_entry.attr,
686 	&queue_atomic_write_unit_min_entry.attr,
687 	&queue_atomic_write_unit_max_entry.attr,
688 	&queue_max_write_zeroes_sectors_entry.attr,
689 	&queue_max_hw_wzeroes_unmap_sectors_entry.attr,
690 	&queue_max_wzeroes_unmap_sectors_entry.attr,
691 	&queue_max_zone_append_sectors_entry.attr,
692 	&queue_zone_write_granularity_entry.attr,
693 	&queue_rotational_entry.attr,
694 	&queue_zoned_entry.attr,
695 	&queue_max_open_zones_entry.attr,
696 	&queue_max_active_zones_entry.attr,
697 	&queue_iostats_passthrough_entry.attr,
698 	&queue_iostats_entry.attr,
699 	&queue_stable_writes_entry.attr,
700 	&queue_add_random_entry.attr,
701 	&queue_wc_entry.attr,
702 	&queue_fua_entry.attr,
703 	&queue_dax_entry.attr,
704 	&queue_virt_boundary_mask_entry.attr,
705 	&queue_dma_alignment_entry.attr,
706 	&queue_ra_entry.attr,
707 
708 	/*
709 	 * Attributes which don't require locking.
710 	 */
711 	&queue_discard_zeroes_data_entry.attr,
712 	&queue_write_same_max_entry.attr,
713 	&queue_nr_zones_entry.attr,
714 	&queue_nomerges_entry.attr,
715 	&queue_poll_entry.attr,
716 	&queue_poll_delay_entry.attr,
717 
718 	NULL,
719 };
720 
721 /* Request-based queue attributes that are not relevant for bio-based queues. */
722 static struct attribute *blk_mq_queue_attrs[] = {
723 	/*
724 	 * Attributes which require some form of locking other than
725 	 * q->sysfs_lock.
726 	 */
727 	&elv_iosched_entry.attr,
728 	&queue_requests_entry.attr,
729 #ifdef CONFIG_BLK_WBT
730 	&queue_wb_lat_entry.attr,
731 #endif
732 	/*
733 	 * Attributes which don't require locking.
734 	 */
735 	&queue_rq_affinity_entry.attr,
736 	&queue_io_timeout_entry.attr,
737 
738 	NULL,
739 };
740 
741 static umode_t queue_attr_visible(struct kobject *kobj, struct attribute *attr,
742 				int n)
743 {
744 	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
745 	struct request_queue *q = disk->queue;
746 
747 	if ((attr == &queue_max_open_zones_entry.attr ||
748 	     attr == &queue_max_active_zones_entry.attr) &&
749 	    !blk_queue_is_zoned(q))
750 		return 0;
751 
752 	return attr->mode;
753 }
754 
755 static umode_t blk_mq_queue_attr_visible(struct kobject *kobj,
756 					 struct attribute *attr, int n)
757 {
758 	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
759 	struct request_queue *q = disk->queue;
760 
761 	if (!queue_is_mq(q))
762 		return 0;
763 
764 	if (attr == &queue_io_timeout_entry.attr && !q->mq_ops->timeout)
765 		return 0;
766 
767 	return attr->mode;
768 }
769 
770 static struct attribute_group queue_attr_group = {
771 	.attrs = queue_attrs,
772 	.is_visible = queue_attr_visible,
773 };
774 
775 static struct attribute_group blk_mq_queue_attr_group = {
776 	.attrs = blk_mq_queue_attrs,
777 	.is_visible = blk_mq_queue_attr_visible,
778 };
779 
780 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
781 
782 static ssize_t
783 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
784 {
785 	struct queue_sysfs_entry *entry = to_queue(attr);
786 	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
787 
788 	if (!entry->show && !entry->show_limit)
789 		return -EIO;
790 
791 	if (entry->show_limit) {
792 		ssize_t res;
793 
794 		mutex_lock(&disk->queue->limits_lock);
795 		res = entry->show_limit(disk, page);
796 		mutex_unlock(&disk->queue->limits_lock);
797 		return res;
798 	}
799 
800 	return entry->show(disk, page);
801 }
802 
803 static ssize_t
804 queue_attr_store(struct kobject *kobj, struct attribute *attr,
805 		    const char *page, size_t length)
806 {
807 	struct queue_sysfs_entry *entry = to_queue(attr);
808 	struct gendisk *disk = container_of(kobj, struct gendisk, queue_kobj);
809 	struct request_queue *q = disk->queue;
810 
811 	if (!entry->store_limit && !entry->store)
812 		return -EIO;
813 
814 	if (entry->store_limit) {
815 		ssize_t res;
816 
817 		struct queue_limits lim = queue_limits_start_update(q);
818 
819 		res = entry->store_limit(disk, page, length, &lim);
820 		if (res < 0) {
821 			queue_limits_cancel_update(q);
822 			return res;
823 		}
824 
825 		res = queue_limits_commit_update_frozen(q, &lim);
826 		if (res)
827 			return res;
828 		return length;
829 	}
830 
831 	return entry->store(disk, page, length);
832 }
833 
834 static const struct sysfs_ops queue_sysfs_ops = {
835 	.show	= queue_attr_show,
836 	.store	= queue_attr_store,
837 };
838 
839 static const struct attribute_group *blk_queue_attr_groups[] = {
840 	&queue_attr_group,
841 	&blk_mq_queue_attr_group,
842 	NULL
843 };
844 
845 static void blk_queue_release(struct kobject *kobj)
846 {
847 	/* nothing to do here, all data is associated with the parent gendisk */
848 }
849 
850 static const struct kobj_type blk_queue_ktype = {
851 	.default_groups = blk_queue_attr_groups,
852 	.sysfs_ops	= &queue_sysfs_ops,
853 	.release	= blk_queue_release,
854 };
855 
856 static void blk_debugfs_remove(struct gendisk *disk)
857 {
858 	struct request_queue *q = disk->queue;
859 
860 	mutex_lock(&q->debugfs_mutex);
861 	blk_trace_shutdown(q);
862 	debugfs_remove_recursive(q->debugfs_dir);
863 	q->debugfs_dir = NULL;
864 	q->sched_debugfs_dir = NULL;
865 	q->rqos_debugfs_dir = NULL;
866 	mutex_unlock(&q->debugfs_mutex);
867 }
868 
869 /**
870  * blk_register_queue - register a block layer queue with sysfs
871  * @disk: Disk of which the request queue should be registered with sysfs.
872  */
873 int blk_register_queue(struct gendisk *disk)
874 {
875 	struct request_queue *q = disk->queue;
876 	int ret;
877 
878 	kobject_init(&disk->queue_kobj, &blk_queue_ktype);
879 	ret = kobject_add(&disk->queue_kobj, &disk_to_dev(disk)->kobj, "queue");
880 	if (ret < 0)
881 		goto out_put_queue_kobj;
882 
883 	if (queue_is_mq(q)) {
884 		ret = blk_mq_sysfs_register(disk);
885 		if (ret)
886 			goto out_put_queue_kobj;
887 	}
888 	mutex_lock(&q->sysfs_lock);
889 
890 	mutex_lock(&q->debugfs_mutex);
891 	q->debugfs_dir = debugfs_create_dir(disk->disk_name, blk_debugfs_root);
892 	if (queue_is_mq(q))
893 		blk_mq_debugfs_register(q);
894 	mutex_unlock(&q->debugfs_mutex);
895 
896 	ret = disk_register_independent_access_ranges(disk);
897 	if (ret)
898 		goto out_debugfs_remove;
899 
900 	ret = blk_crypto_sysfs_register(disk);
901 	if (ret)
902 		goto out_unregister_ia_ranges;
903 
904 	if (queue_is_mq(q))
905 		elevator_set_default(q);
906 	wbt_enable_default(disk);
907 
908 	blk_queue_flag_set(QUEUE_FLAG_REGISTERED, q);
909 
910 	/* Now everything is ready and send out KOBJ_ADD uevent */
911 	kobject_uevent(&disk->queue_kobj, KOBJ_ADD);
912 	if (q->elevator)
913 		kobject_uevent(&q->elevator->kobj, KOBJ_ADD);
914 	mutex_unlock(&q->sysfs_lock);
915 
916 	/*
917 	 * SCSI probing may synchronously create and destroy a lot of
918 	 * request_queues for non-existent devices.  Shutting down a fully
919 	 * functional queue takes measureable wallclock time as RCU grace
920 	 * periods are involved.  To avoid excessive latency in these
921 	 * cases, a request_queue starts out in a degraded mode which is
922 	 * faster to shut down and is made fully functional here as
923 	 * request_queues for non-existent devices never get registered.
924 	 */
925 	blk_queue_flag_set(QUEUE_FLAG_INIT_DONE, q);
926 	percpu_ref_switch_to_percpu(&q->q_usage_counter);
927 
928 	return ret;
929 
930 out_unregister_ia_ranges:
931 	disk_unregister_independent_access_ranges(disk);
932 out_debugfs_remove:
933 	blk_debugfs_remove(disk);
934 	mutex_unlock(&q->sysfs_lock);
935 	if (queue_is_mq(q))
936 		blk_mq_sysfs_unregister(disk);
937 out_put_queue_kobj:
938 	kobject_put(&disk->queue_kobj);
939 	return ret;
940 }
941 
942 /**
943  * blk_unregister_queue - counterpart of blk_register_queue()
944  * @disk: Disk of which the request queue should be unregistered from sysfs.
945  *
946  * Note: the caller is responsible for guaranteeing that this function is called
947  * after blk_register_queue() has finished.
948  */
949 void blk_unregister_queue(struct gendisk *disk)
950 {
951 	struct request_queue *q = disk->queue;
952 
953 	if (WARN_ON(!q))
954 		return;
955 
956 	/* Return early if disk->queue was never registered. */
957 	if (!blk_queue_registered(q))
958 		return;
959 
960 	/*
961 	 * Since sysfs_remove_dir() prevents adding new directory entries
962 	 * before removal of existing entries starts, protect against
963 	 * concurrent elv_iosched_store() calls.
964 	 */
965 	mutex_lock(&q->sysfs_lock);
966 	blk_queue_flag_clear(QUEUE_FLAG_REGISTERED, q);
967 	mutex_unlock(&q->sysfs_lock);
968 
969 	/*
970 	 * Remove the sysfs attributes before unregistering the queue data
971 	 * structures that can be modified through sysfs.
972 	 */
973 	if (queue_is_mq(q))
974 		blk_mq_sysfs_unregister(disk);
975 	blk_crypto_sysfs_unregister(disk);
976 
977 	mutex_lock(&q->sysfs_lock);
978 	disk_unregister_independent_access_ranges(disk);
979 	mutex_unlock(&q->sysfs_lock);
980 
981 	/* Now that we've deleted all child objects, we can delete the queue. */
982 	kobject_uevent(&disk->queue_kobj, KOBJ_REMOVE);
983 	kobject_del(&disk->queue_kobj);
984 
985 	if (queue_is_mq(q))
986 		elevator_set_none(q);
987 
988 	blk_debugfs_remove(disk);
989 	kobject_put(&disk->queue_kobj);
990 }
991