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Jens Axboe8324aa92008-01-29 14:51:59 +01001/*
2 * Functions related to sysfs handling
3 */
4#include <linux/kernel.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09005#include <linux/slab.h>
Jens Axboe8324aa92008-01-29 14:51:59 +01006#include <linux/module.h>
7#include <linux/bio.h>
8#include <linux/blkdev.h>
9#include <linux/blktrace_api.h>
Jens Axboe320ae512013-10-24 09:20:05 +010010#include <linux/blk-mq.h>
Jens Axboe8324aa92008-01-29 14:51:59 +010011
12#include "blk.h"
Tejun Heo5efd6112012-03-05 13:15:12 -080013#include "blk-cgroup.h"
Ming Lei3edcc0c2013-12-26 21:31:38 +080014#include "blk-mq.h"
Jens Axboe8324aa92008-01-29 14:51:59 +010015
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
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080023queue_var_show(unsigned long var, char *page)
Jens Axboe8324aa92008-01-29 14:51:59 +010024{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080025 return sprintf(page, "%lu\n", var);
Jens Axboe8324aa92008-01-29 14:51:59 +010026}
27
28static ssize_t
29queue_var_store(unsigned long *var, const char *page, size_t count)
30{
Dave Reisnerb1f3b642012-09-08 11:55:45 -040031 int err;
32 unsigned long v;
Jens Axboe8324aa92008-01-29 14:51:59 +010033
Jingoo Haned751e62013-09-11 14:20:08 -070034 err = kstrtoul(page, 10, &v);
Dave Reisnerb1f3b642012-09-08 11:55:45 -040035 if (err || v > UINT_MAX)
36 return -EINVAL;
37
38 *var = v;
39
Jens Axboe8324aa92008-01-29 14:51:59 +010040 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{
Jens Axboe8324aa92008-01-29 14:51:59 +010051 unsigned long nr;
Jens Axboee3a2b3f2014-05-20 11:49:02 -060052 int ret, err;
Jens Axboeb8a9ae72009-09-11 22:44:29 +020053
Jens Axboee3a2b3f2014-05-20 11:49:02 -060054 if (!q->request_fn && !q->mq_ops)
Jens Axboeb8a9ae72009-09-11 22:44:29 +020055 return -EINVAL;
56
57 ret = queue_var_store(&nr, page, count);
Dave Reisnerb1f3b642012-09-08 11:55:45 -040058 if (ret < 0)
59 return ret;
60
Jens Axboe8324aa92008-01-29 14:51:59 +010061 if (nr < BLKDEV_MIN_RQ)
62 nr = BLKDEV_MIN_RQ;
63
Jens Axboee3a2b3f2014-05-20 11:49:02 -060064 if (q->request_fn)
65 err = blk_update_nr_requests(q, nr);
66 else
67 err = blk_mq_update_nr_requests(q, nr);
Jens Axboe8324aa92008-01-29 14:51:59 +010068
Jens Axboee3a2b3f2014-05-20 11:49:02 -060069 if (err)
70 return err;
Tejun Heoa0516612012-06-26 15:05:44 -070071
Jens Axboe8324aa92008-01-29 14:51:59 +010072 return ret;
73}
74
75static ssize_t queue_ra_show(struct request_queue *q, char *page)
76{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080077 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
78 (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +010079
80 return queue_var_show(ra_kb, (page));
81}
82
83static ssize_t
84queue_ra_store(struct request_queue *q, const char *page, size_t count)
85{
86 unsigned long ra_kb;
87 ssize_t ret = queue_var_store(&ra_kb, page, count);
88
Dave Reisnerb1f3b642012-09-08 11:55:45 -040089 if (ret < 0)
90 return ret;
91
Jens Axboe8324aa92008-01-29 14:51:59 +010092 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +010093
94 return ret;
95}
96
97static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
98{
Martin K. Petersenae03bf62009-05-22 17:17:50 -040099 int max_sectors_kb = queue_max_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100100
101 return queue_var_show(max_sectors_kb, (page));
102}
103
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500104static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
105{
106 return queue_var_show(queue_max_segments(q), (page));
107}
108
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200109static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
110{
111 return queue_var_show(q->limits.max_integrity_segments, (page));
112}
113
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500114static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
115{
Martin K. Petersene692cb62010-12-01 19:41:49 +0100116 if (blk_queue_cluster(q))
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500117 return queue_var_show(queue_max_segment_size(q), (page));
118
119 return queue_var_show(PAGE_CACHE_SIZE, (page));
120}
121
Martin K. Petersene1defc42009-05-22 17:17:49 -0400122static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
Martin K. Petersene68b9032008-01-29 19:14:08 +0100123{
Martin K. Petersene1defc42009-05-22 17:17:49 -0400124 return queue_var_show(queue_logical_block_size(q), page);
Martin K. Petersene68b9032008-01-29 19:14:08 +0100125}
126
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400127static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
128{
129 return queue_var_show(queue_physical_block_size(q), page);
130}
131
132static ssize_t queue_io_min_show(struct request_queue *q, char *page)
133{
134 return queue_var_show(queue_io_min(q), page);
135}
136
137static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
138{
139 return queue_var_show(queue_io_opt(q), page);
Jens Axboe8324aa92008-01-29 14:51:59 +0100140}
141
Martin K. Petersen86b37282009-11-10 11:50:21 +0100142static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
143{
144 return queue_var_show(q->limits.discard_granularity, page);
145}
146
147static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
148{
Martin K. Petersena934a002011-05-18 10:37:35 +0200149 return sprintf(page, "%llu\n",
150 (unsigned long long)q->limits.max_discard_sectors << 9);
Martin K. Petersen86b37282009-11-10 11:50:21 +0100151}
152
Martin K. Petersen98262f22009-12-03 09:24:48 +0100153static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
154{
155 return queue_var_show(queue_discard_zeroes_data(q), page);
156}
157
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400158static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
159{
160 return sprintf(page, "%llu\n",
161 (unsigned long long)q->limits.max_write_same_sectors << 9);
162}
163
164
Jens Axboe8324aa92008-01-29 14:51:59 +0100165static ssize_t
166queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
167{
168 unsigned long max_sectors_kb,
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400169 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
Jens Axboe8324aa92008-01-29 14:51:59 +0100170 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
171 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
172
Dave Reisnerb1f3b642012-09-08 11:55:45 -0400173 if (ret < 0)
174 return ret;
175
Jens Axboe8324aa92008-01-29 14:51:59 +0100176 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
177 return -EINVAL;
Wu Fengguang7c239512008-11-25 09:08:39 +0100178
Jens Axboe8324aa92008-01-29 14:51:59 +0100179 spin_lock_irq(q->queue_lock);
Nikanth Karthikesanc295fc02009-09-01 22:40:15 +0200180 q->limits.max_sectors = max_sectors_kb << 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100181 spin_unlock_irq(q->queue_lock);
182
183 return ret;
184}
185
186static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
187{
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400188 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100189
190 return queue_var_show(max_hw_sectors_kb, (page));
191}
192
Jens Axboe956bcb72010-08-07 18:13:50 +0200193#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
194static ssize_t \
195queue_show_##name(struct request_queue *q, char *page) \
196{ \
197 int bit; \
198 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
199 return queue_var_show(neg ? !bit : bit, page); \
200} \
201static ssize_t \
202queue_store_##name(struct request_queue *q, const char *page, size_t count) \
203{ \
204 unsigned long val; \
205 ssize_t ret; \
206 ret = queue_var_store(&val, page, count); \
Arnd Bergmannc678ef52013-04-03 21:53:57 +0200207 if (ret < 0) \
208 return ret; \
Jens Axboe956bcb72010-08-07 18:13:50 +0200209 if (neg) \
210 val = !val; \
211 \
212 spin_lock_irq(q->queue_lock); \
213 if (val) \
214 queue_flag_set(QUEUE_FLAG_##flag, q); \
215 else \
216 queue_flag_clear(QUEUE_FLAG_##flag, q); \
217 spin_unlock_irq(q->queue_lock); \
218 return ret; \
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100219}
220
Jens Axboe956bcb72010-08-07 18:13:50 +0200221QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
222QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
223QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
224#undef QUEUE_SYSFS_BIT_FNS
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100225
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200226static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
227{
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100228 return queue_var_show((blk_queue_nomerges(q) << 1) |
229 blk_queue_noxmerges(q), page);
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200230}
231
232static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
233 size_t count)
234{
235 unsigned long nm;
236 ssize_t ret = queue_var_store(&nm, page, count);
237
Dave Reisnerb1f3b642012-09-08 11:55:45 -0400238 if (ret < 0)
239 return ret;
240
Jens Axboebf0f9702008-05-07 09:09:39 +0200241 spin_lock_irq(q->queue_lock);
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100242 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
243 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
244 if (nm == 2)
Jens Axboebf0f9702008-05-07 09:09:39 +0200245 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100246 else if (nm)
247 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
Jens Axboebf0f9702008-05-07 09:09:39 +0200248 spin_unlock_irq(q->queue_lock);
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100249
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200250 return ret;
251}
252
Jens Axboec7c22e42008-09-13 20:26:01 +0200253static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
254{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +0800255 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
Dan Williams5757a6d2011-07-23 20:44:25 +0200256 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
Jens Axboec7c22e42008-09-13 20:26:01 +0200257
Dan Williams5757a6d2011-07-23 20:44:25 +0200258 return queue_var_show(set << force, page);
Jens Axboec7c22e42008-09-13 20:26:01 +0200259}
260
261static ssize_t
262queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
263{
264 ssize_t ret = -EINVAL;
Christoph Hellwig0a06ff02013-11-14 14:32:07 -0800265#ifdef CONFIG_SMP
Jens Axboec7c22e42008-09-13 20:26:01 +0200266 unsigned long val;
267
268 ret = queue_var_store(&val, page, count);
Dave Reisnerb1f3b642012-09-08 11:55:45 -0400269 if (ret < 0)
270 return ret;
271
Jens Axboec7c22e42008-09-13 20:26:01 +0200272 spin_lock_irq(q->queue_lock);
Eric Seppanene8037d42011-08-23 21:25:12 +0200273 if (val == 2) {
Jens Axboec7c22e42008-09-13 20:26:01 +0200274 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
Eric Seppanene8037d42011-08-23 21:25:12 +0200275 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
276 } else if (val == 1) {
277 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
278 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
279 } else if (val == 0) {
Dan Williams5757a6d2011-07-23 20:44:25 +0200280 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
281 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
282 }
Jens Axboec7c22e42008-09-13 20:26:01 +0200283 spin_unlock_irq(q->queue_lock);
284#endif
285 return ret;
286}
Jens Axboe8324aa92008-01-29 14:51:59 +0100287
288static struct queue_sysfs_entry queue_requests_entry = {
289 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
290 .show = queue_requests_show,
291 .store = queue_requests_store,
292};
293
294static struct queue_sysfs_entry queue_ra_entry = {
295 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
296 .show = queue_ra_show,
297 .store = queue_ra_store,
298};
299
300static struct queue_sysfs_entry queue_max_sectors_entry = {
301 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
302 .show = queue_max_sectors_show,
303 .store = queue_max_sectors_store,
304};
305
306static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
307 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
308 .show = queue_max_hw_sectors_show,
309};
310
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500311static struct queue_sysfs_entry queue_max_segments_entry = {
312 .attr = {.name = "max_segments", .mode = S_IRUGO },
313 .show = queue_max_segments_show,
314};
315
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200316static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
317 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
318 .show = queue_max_integrity_segments_show,
319};
320
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500321static struct queue_sysfs_entry queue_max_segment_size_entry = {
322 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
323 .show = queue_max_segment_size_show,
324};
325
Jens Axboe8324aa92008-01-29 14:51:59 +0100326static struct queue_sysfs_entry queue_iosched_entry = {
327 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
328 .show = elv_iosched_show,
329 .store = elv_iosched_store,
330};
331
Martin K. Petersene68b9032008-01-29 19:14:08 +0100332static struct queue_sysfs_entry queue_hw_sector_size_entry = {
333 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
Martin K. Petersene1defc42009-05-22 17:17:49 -0400334 .show = queue_logical_block_size_show,
335};
336
337static struct queue_sysfs_entry queue_logical_block_size_entry = {
338 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
339 .show = queue_logical_block_size_show,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100340};
341
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400342static struct queue_sysfs_entry queue_physical_block_size_entry = {
343 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
344 .show = queue_physical_block_size_show,
345};
346
347static struct queue_sysfs_entry queue_io_min_entry = {
348 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
349 .show = queue_io_min_show,
350};
351
352static struct queue_sysfs_entry queue_io_opt_entry = {
353 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
354 .show = queue_io_opt_show,
Jens Axboe8324aa92008-01-29 14:51:59 +0100355};
356
Martin K. Petersen86b37282009-11-10 11:50:21 +0100357static struct queue_sysfs_entry queue_discard_granularity_entry = {
358 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
359 .show = queue_discard_granularity_show,
360};
361
362static struct queue_sysfs_entry queue_discard_max_entry = {
363 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
364 .show = queue_discard_max_show,
365};
366
Martin K. Petersen98262f22009-12-03 09:24:48 +0100367static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
368 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
369 .show = queue_discard_zeroes_data_show,
370};
371
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400372static struct queue_sysfs_entry queue_write_same_max_entry = {
373 .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
374 .show = queue_write_same_max_show,
375};
376
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100377static struct queue_sysfs_entry queue_nonrot_entry = {
378 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200379 .show = queue_show_nonrot,
380 .store = queue_store_nonrot,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100381};
382
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200383static struct queue_sysfs_entry queue_nomerges_entry = {
384 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
385 .show = queue_nomerges_show,
386 .store = queue_nomerges_store,
387};
388
Jens Axboec7c22e42008-09-13 20:26:01 +0200389static struct queue_sysfs_entry queue_rq_affinity_entry = {
390 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
391 .show = queue_rq_affinity_show,
392 .store = queue_rq_affinity_store,
393};
394
Jens Axboebc58ba92009-01-23 10:54:44 +0100395static struct queue_sysfs_entry queue_iostats_entry = {
396 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200397 .show = queue_show_iostats,
398 .store = queue_store_iostats,
Jens Axboebc58ba92009-01-23 10:54:44 +0100399};
400
Jens Axboee2e1a142010-06-09 10:42:09 +0200401static struct queue_sysfs_entry queue_random_entry = {
402 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200403 .show = queue_show_random,
404 .store = queue_store_random,
Jens Axboee2e1a142010-06-09 10:42:09 +0200405};
406
Jens Axboe8324aa92008-01-29 14:51:59 +0100407static struct attribute *default_attrs[] = {
408 &queue_requests_entry.attr,
409 &queue_ra_entry.attr,
410 &queue_max_hw_sectors_entry.attr,
411 &queue_max_sectors_entry.attr,
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500412 &queue_max_segments_entry.attr,
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200413 &queue_max_integrity_segments_entry.attr,
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500414 &queue_max_segment_size_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100415 &queue_iosched_entry.attr,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100416 &queue_hw_sector_size_entry.attr,
Martin K. Petersene1defc42009-05-22 17:17:49 -0400417 &queue_logical_block_size_entry.attr,
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400418 &queue_physical_block_size_entry.attr,
419 &queue_io_min_entry.attr,
420 &queue_io_opt_entry.attr,
Martin K. Petersen86b37282009-11-10 11:50:21 +0100421 &queue_discard_granularity_entry.attr,
422 &queue_discard_max_entry.attr,
Martin K. Petersen98262f22009-12-03 09:24:48 +0100423 &queue_discard_zeroes_data_entry.attr,
Martin K. Petersen4363ac72012-09-18 12:19:27 -0400424 &queue_write_same_max_entry.attr,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100425 &queue_nonrot_entry.attr,
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200426 &queue_nomerges_entry.attr,
Jens Axboec7c22e42008-09-13 20:26:01 +0200427 &queue_rq_affinity_entry.attr,
Jens Axboebc58ba92009-01-23 10:54:44 +0100428 &queue_iostats_entry.attr,
Jens Axboee2e1a142010-06-09 10:42:09 +0200429 &queue_random_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100430 NULL,
431};
432
433#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
434
435static ssize_t
436queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
437{
438 struct queue_sysfs_entry *entry = to_queue(attr);
439 struct request_queue *q =
440 container_of(kobj, struct request_queue, kobj);
441 ssize_t res;
442
443 if (!entry->show)
444 return -EIO;
445 mutex_lock(&q->sysfs_lock);
Bart Van Assche3f3299d2012-11-28 13:42:38 +0100446 if (blk_queue_dying(q)) {
Jens Axboe8324aa92008-01-29 14:51:59 +0100447 mutex_unlock(&q->sysfs_lock);
448 return -ENOENT;
449 }
450 res = entry->show(q, page);
451 mutex_unlock(&q->sysfs_lock);
452 return res;
453}
454
455static ssize_t
456queue_attr_store(struct kobject *kobj, struct attribute *attr,
457 const char *page, size_t length)
458{
459 struct queue_sysfs_entry *entry = to_queue(attr);
Jens Axboe6728cb02008-01-31 13:03:55 +0100460 struct request_queue *q;
Jens Axboe8324aa92008-01-29 14:51:59 +0100461 ssize_t res;
462
463 if (!entry->store)
464 return -EIO;
Jens Axboe6728cb02008-01-31 13:03:55 +0100465
466 q = container_of(kobj, struct request_queue, kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100467 mutex_lock(&q->sysfs_lock);
Bart Van Assche3f3299d2012-11-28 13:42:38 +0100468 if (blk_queue_dying(q)) {
Jens Axboe8324aa92008-01-29 14:51:59 +0100469 mutex_unlock(&q->sysfs_lock);
470 return -ENOENT;
471 }
472 res = entry->store(q, page, length);
473 mutex_unlock(&q->sysfs_lock);
474 return res;
475}
476
Tejun Heo548bc8e2013-01-09 08:05:13 -0800477static void blk_free_queue_rcu(struct rcu_head *rcu_head)
478{
479 struct request_queue *q = container_of(rcu_head, struct request_queue,
480 rcu_head);
481 kmem_cache_free(blk_requestq_cachep, q);
482}
483
Jens Axboe8324aa92008-01-29 14:51:59 +0100484/**
Andrew Morton499337b2011-09-21 10:01:22 +0200485 * blk_release_queue: - release a &struct request_queue when it is no longer needed
486 * @kobj: the kobj belonging to the request queue to be released
Jens Axboe8324aa92008-01-29 14:51:59 +0100487 *
488 * Description:
Andrew Morton499337b2011-09-21 10:01:22 +0200489 * blk_release_queue is the pair to blk_init_queue() or
Jens Axboe8324aa92008-01-29 14:51:59 +0100490 * blk_queue_make_request(). It should be called when a request queue is
491 * being released; typically when a block device is being de-registered.
492 * Currently, its primary task it to free all the &struct request
493 * structures that were allocated to the queue and the queue itself.
494 *
495 * Caveat:
496 * Hopefully the low level driver will have finished any
497 * outstanding requests first...
498 **/
499static void blk_release_queue(struct kobject *kobj)
500{
501 struct request_queue *q =
502 container_of(kobj, struct request_queue, kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100503
504 blk_sync_queue(q);
505
Tejun Heoe8989fa2012-03-05 13:15:20 -0800506 blkcg_exit_queue(q);
507
Tejun Heo7e5a8792011-12-14 00:33:42 +0100508 if (q->elevator) {
509 spin_lock_irq(q->queue_lock);
510 ioc_clear_queue(q);
511 spin_unlock_irq(q->queue_lock);
Hannes Reinecke777eb1b2011-09-28 08:07:01 -0600512 elevator_exit(q->elevator);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100513 }
Hannes Reinecke777eb1b2011-09-28 08:07:01 -0600514
Tejun Heoa0516612012-06-26 15:05:44 -0700515 blk_exit_rl(&q->root_rl);
Jens Axboe8324aa92008-01-29 14:51:59 +0100516
517 if (q->queue_tags)
518 __blk_queue_free_tags(q);
519
Jens Axboe320ae512013-10-24 09:20:05 +0100520 if (q->mq_ops)
521 blk_mq_free_queue(q);
Ming Leif70ced02014-09-25 23:23:47 +0800522 else
523 blk_free_flush_queue(q->fq);
Christoph Hellwig18741982014-02-10 09:29:00 -0700524
Jens Axboe8324aa92008-01-29 14:51:59 +0100525 blk_trace_shutdown(q);
526
527 bdi_destroy(&q->backing_dev_info);
Tejun Heoa73f7302011-12-14 00:33:37 +0100528
529 ida_simple_remove(&blk_queue_ida, q->id);
Tejun Heo548bc8e2013-01-09 08:05:13 -0800530 call_rcu(&q->rcu_head, blk_free_queue_rcu);
Jens Axboe8324aa92008-01-29 14:51:59 +0100531}
532
Emese Revfy52cf25d2010-01-19 02:58:23 +0100533static const struct sysfs_ops queue_sysfs_ops = {
Jens Axboe8324aa92008-01-29 14:51:59 +0100534 .show = queue_attr_show,
535 .store = queue_attr_store,
536};
537
538struct kobj_type blk_queue_ktype = {
539 .sysfs_ops = &queue_sysfs_ops,
540 .default_attrs = default_attrs,
541 .release = blk_release_queue,
542};
543
544int blk_register_queue(struct gendisk *disk)
545{
546 int ret;
Li Zefan1d54ad62009-04-14 14:00:05 +0800547 struct device *dev = disk_to_dev(disk);
Jens Axboe8324aa92008-01-29 14:51:59 +0100548 struct request_queue *q = disk->queue;
549
Akinobu Mitafb199742008-04-21 09:51:06 +0200550 if (WARN_ON(!q))
Jens Axboe8324aa92008-01-29 14:51:59 +0100551 return -ENXIO;
552
Tejun Heo749fefe2012-09-20 14:08:52 -0700553 /*
Tejun Heo17497ac2014-09-24 13:31:50 -0400554 * SCSI probing may synchronously create and destroy a lot of
555 * request_queues for non-existent devices. Shutting down a fully
556 * functional queue takes measureable wallclock time as RCU grace
557 * periods are involved. To avoid excessive latency in these
558 * cases, a request_queue starts out in a degraded mode which is
559 * faster to shut down and is made fully functional here as
560 * request_queues for non-existent devices never get registered.
Tejun Heo749fefe2012-09-20 14:08:52 -0700561 */
Alan Sterndf35c7c2014-09-09 11:50:58 -0400562 if (!blk_queue_init_done(q)) {
563 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
564 blk_queue_bypass_end(q);
Tejun Heo17497ac2014-09-24 13:31:50 -0400565 if (q->mq_ops)
566 blk_mq_finish_init(q);
Alan Sterndf35c7c2014-09-09 11:50:58 -0400567 }
Tejun Heo749fefe2012-09-20 14:08:52 -0700568
Li Zefan1d54ad62009-04-14 14:00:05 +0800569 ret = blk_trace_init_sysfs(dev);
570 if (ret)
571 return ret;
572
Linus Torvaldsc9059592009-06-11 10:52:27 -0700573 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
Liu Yuaned5302d2011-04-19 13:47:58 +0200574 if (ret < 0) {
575 blk_trace_remove_sysfs(dev);
Jens Axboe8324aa92008-01-29 14:51:59 +0100576 return ret;
Liu Yuaned5302d2011-04-19 13:47:58 +0200577 }
Jens Axboe8324aa92008-01-29 14:51:59 +0100578
579 kobject_uevent(&q->kobj, KOBJ_ADD);
580
Jens Axboe320ae512013-10-24 09:20:05 +0100581 if (q->mq_ops)
582 blk_mq_register_disk(disk);
583
Martin K. Petersencd43e262009-05-22 17:17:52 -0400584 if (!q->request_fn)
585 return 0;
586
Jens Axboe8324aa92008-01-29 14:51:59 +0100587 ret = elv_register_queue(q);
588 if (ret) {
589 kobject_uevent(&q->kobj, KOBJ_REMOVE);
590 kobject_del(&q->kobj);
Liu Yuan80656b62011-04-13 22:14:54 +0200591 blk_trace_remove_sysfs(dev);
Xiaotian Fengc87ffbb2010-08-23 12:30:29 +0200592 kobject_put(&dev->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100593 return ret;
594 }
595
596 return 0;
597}
598
599void blk_unregister_queue(struct gendisk *disk)
600{
601 struct request_queue *q = disk->queue;
602
Akinobu Mitafb199742008-04-21 09:51:06 +0200603 if (WARN_ON(!q))
604 return;
605
Jens Axboe320ae512013-10-24 09:20:05 +0100606 if (q->mq_ops)
607 blk_mq_unregister_disk(disk);
608
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +0200609 if (q->request_fn)
Jens Axboe8324aa92008-01-29 14:51:59 +0100610 elv_unregister_queue(q);
611
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +0200612 kobject_uevent(&q->kobj, KOBJ_REMOVE);
613 kobject_del(&q->kobj);
614 blk_trace_remove_sysfs(disk_to_dev(disk));
615 kobject_put(&disk_to_dev(disk)->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100616}