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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>
10
11#include "blk.h"
Tejun Heo5efd6112012-03-05 13:15:12 -080012#include "blk-cgroup.h"
Jens Axboe8324aa92008-01-29 14:51:59 +010013
14struct queue_sysfs_entry {
15 struct attribute attr;
16 ssize_t (*show)(struct request_queue *, char *);
17 ssize_t (*store)(struct request_queue *, const char *, size_t);
18};
19
20static ssize_t
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080021queue_var_show(unsigned long var, char *page)
Jens Axboe8324aa92008-01-29 14:51:59 +010022{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080023 return sprintf(page, "%lu\n", var);
Jens Axboe8324aa92008-01-29 14:51:59 +010024}
25
26static ssize_t
27queue_var_store(unsigned long *var, const char *page, size_t count)
28{
29 char *p = (char *) page;
30
31 *var = simple_strtoul(p, &p, 10);
32 return count;
33}
34
35static ssize_t queue_requests_show(struct request_queue *q, char *page)
36{
37 return queue_var_show(q->nr_requests, (page));
38}
39
40static ssize_t
41queue_requests_store(struct request_queue *q, const char *page, size_t count)
42{
43 struct request_list *rl = &q->rq;
44 unsigned long nr;
Jens Axboeb8a9ae72009-09-11 22:44:29 +020045 int ret;
46
47 if (!q->request_fn)
48 return -EINVAL;
49
50 ret = queue_var_store(&nr, page, count);
Jens Axboe8324aa92008-01-29 14:51:59 +010051 if (nr < BLKDEV_MIN_RQ)
52 nr = BLKDEV_MIN_RQ;
53
54 spin_lock_irq(q->queue_lock);
55 q->nr_requests = nr;
56 blk_queue_congestion_threshold(q);
57
Jens Axboe1faa16d2009-04-06 14:48:01 +020058 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
59 blk_set_queue_congested(q, BLK_RW_SYNC);
60 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
61 blk_clear_queue_congested(q, BLK_RW_SYNC);
Jens Axboe8324aa92008-01-29 14:51:59 +010062
Jens Axboe1faa16d2009-04-06 14:48:01 +020063 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
64 blk_set_queue_congested(q, BLK_RW_ASYNC);
65 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
66 blk_clear_queue_congested(q, BLK_RW_ASYNC);
Jens Axboe8324aa92008-01-29 14:51:59 +010067
Jens Axboe1faa16d2009-04-06 14:48:01 +020068 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
69 blk_set_queue_full(q, BLK_RW_SYNC);
Tao Ma60735b62011-04-19 13:50:40 +020070 } else {
Jens Axboe1faa16d2009-04-06 14:48:01 +020071 blk_clear_queue_full(q, BLK_RW_SYNC);
72 wake_up(&rl->wait[BLK_RW_SYNC]);
Jens Axboe8324aa92008-01-29 14:51:59 +010073 }
74
Jens Axboe1faa16d2009-04-06 14:48:01 +020075 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
76 blk_set_queue_full(q, BLK_RW_ASYNC);
Tao Ma60735b62011-04-19 13:50:40 +020077 } else {
Jens Axboe1faa16d2009-04-06 14:48:01 +020078 blk_clear_queue_full(q, BLK_RW_ASYNC);
79 wake_up(&rl->wait[BLK_RW_ASYNC]);
Jens Axboe8324aa92008-01-29 14:51:59 +010080 }
81 spin_unlock_irq(q->queue_lock);
82 return ret;
83}
84
85static ssize_t queue_ra_show(struct request_queue *q, char *page)
86{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080087 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
88 (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +010089
90 return queue_var_show(ra_kb, (page));
91}
92
93static ssize_t
94queue_ra_store(struct request_queue *q, const char *page, size_t count)
95{
96 unsigned long ra_kb;
97 ssize_t ret = queue_var_store(&ra_kb, page, count);
98
Jens Axboe8324aa92008-01-29 14:51:59 +010099 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +0100100
101 return ret;
102}
103
104static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
105{
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400106 int max_sectors_kb = queue_max_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100107
108 return queue_var_show(max_sectors_kb, (page));
109}
110
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500111static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
112{
113 return queue_var_show(queue_max_segments(q), (page));
114}
115
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200116static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
117{
118 return queue_var_show(q->limits.max_integrity_segments, (page));
119}
120
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500121static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
122{
Martin K. Petersene692cb62010-12-01 19:41:49 +0100123 if (blk_queue_cluster(q))
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500124 return queue_var_show(queue_max_segment_size(q), (page));
125
126 return queue_var_show(PAGE_CACHE_SIZE, (page));
127}
128
Martin K. Petersene1defc42009-05-22 17:17:49 -0400129static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
Martin K. Petersene68b9032008-01-29 19:14:08 +0100130{
Martin K. Petersene1defc42009-05-22 17:17:49 -0400131 return queue_var_show(queue_logical_block_size(q), page);
Martin K. Petersene68b9032008-01-29 19:14:08 +0100132}
133
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400134static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
135{
136 return queue_var_show(queue_physical_block_size(q), page);
137}
138
139static ssize_t queue_io_min_show(struct request_queue *q, char *page)
140{
141 return queue_var_show(queue_io_min(q), page);
142}
143
144static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
145{
146 return queue_var_show(queue_io_opt(q), page);
Jens Axboe8324aa92008-01-29 14:51:59 +0100147}
148
Martin K. Petersen86b37282009-11-10 11:50:21 +0100149static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
150{
151 return queue_var_show(q->limits.discard_granularity, page);
152}
153
154static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
155{
Martin K. Petersena934a002011-05-18 10:37:35 +0200156 return sprintf(page, "%llu\n",
157 (unsigned long long)q->limits.max_discard_sectors << 9);
Martin K. Petersen86b37282009-11-10 11:50:21 +0100158}
159
Martin K. Petersen98262f22009-12-03 09:24:48 +0100160static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
161{
162 return queue_var_show(queue_discard_zeroes_data(q), page);
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
173 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
174 return -EINVAL;
Wu Fengguang7c239512008-11-25 09:08:39 +0100175
Jens Axboe8324aa92008-01-29 14:51:59 +0100176 spin_lock_irq(q->queue_lock);
Nikanth Karthikesanc295fc02009-09-01 22:40:15 +0200177 q->limits.max_sectors = max_sectors_kb << 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100178 spin_unlock_irq(q->queue_lock);
179
180 return ret;
181}
182
183static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
184{
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400185 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100186
187 return queue_var_show(max_hw_sectors_kb, (page));
188}
189
Jens Axboe956bcb72010-08-07 18:13:50 +0200190#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
191static ssize_t \
192queue_show_##name(struct request_queue *q, char *page) \
193{ \
194 int bit; \
195 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
196 return queue_var_show(neg ? !bit : bit, page); \
197} \
198static ssize_t \
199queue_store_##name(struct request_queue *q, const char *page, size_t count) \
200{ \
201 unsigned long val; \
202 ssize_t ret; \
203 ret = queue_var_store(&val, page, count); \
204 if (neg) \
205 val = !val; \
206 \
207 spin_lock_irq(q->queue_lock); \
208 if (val) \
209 queue_flag_set(QUEUE_FLAG_##flag, q); \
210 else \
211 queue_flag_clear(QUEUE_FLAG_##flag, q); \
212 spin_unlock_irq(q->queue_lock); \
213 return ret; \
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100214}
215
Jens Axboe956bcb72010-08-07 18:13:50 +0200216QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
217QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
218QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
219#undef QUEUE_SYSFS_BIT_FNS
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100220
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200221static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
222{
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100223 return queue_var_show((blk_queue_nomerges(q) << 1) |
224 blk_queue_noxmerges(q), page);
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200225}
226
227static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
228 size_t count)
229{
230 unsigned long nm;
231 ssize_t ret = queue_var_store(&nm, page, count);
232
Jens Axboebf0f9702008-05-07 09:09:39 +0200233 spin_lock_irq(q->queue_lock);
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100234 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
235 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
236 if (nm == 2)
Jens Axboebf0f9702008-05-07 09:09:39 +0200237 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100238 else if (nm)
239 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
Jens Axboebf0f9702008-05-07 09:09:39 +0200240 spin_unlock_irq(q->queue_lock);
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100241
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200242 return ret;
243}
244
Jens Axboec7c22e42008-09-13 20:26:01 +0200245static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
246{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +0800247 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
Dan Williams5757a6d2011-07-23 20:44:25 +0200248 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
Jens Axboec7c22e42008-09-13 20:26:01 +0200249
Dan Williams5757a6d2011-07-23 20:44:25 +0200250 return queue_var_show(set << force, page);
Jens Axboec7c22e42008-09-13 20:26:01 +0200251}
252
253static ssize_t
254queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
255{
256 ssize_t ret = -EINVAL;
257#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
258 unsigned long val;
259
260 ret = queue_var_store(&val, page, count);
261 spin_lock_irq(q->queue_lock);
Eric Seppanene8037d42011-08-23 21:25:12 +0200262 if (val == 2) {
Jens Axboec7c22e42008-09-13 20:26:01 +0200263 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
Eric Seppanene8037d42011-08-23 21:25:12 +0200264 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
265 } else if (val == 1) {
266 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
267 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
268 } else if (val == 0) {
Dan Williams5757a6d2011-07-23 20:44:25 +0200269 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
270 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
271 }
Jens Axboec7c22e42008-09-13 20:26:01 +0200272 spin_unlock_irq(q->queue_lock);
273#endif
274 return ret;
275}
Jens Axboe8324aa92008-01-29 14:51:59 +0100276
277static struct queue_sysfs_entry queue_requests_entry = {
278 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
279 .show = queue_requests_show,
280 .store = queue_requests_store,
281};
282
283static struct queue_sysfs_entry queue_ra_entry = {
284 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
285 .show = queue_ra_show,
286 .store = queue_ra_store,
287};
288
289static struct queue_sysfs_entry queue_max_sectors_entry = {
290 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
291 .show = queue_max_sectors_show,
292 .store = queue_max_sectors_store,
293};
294
295static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
296 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
297 .show = queue_max_hw_sectors_show,
298};
299
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500300static struct queue_sysfs_entry queue_max_segments_entry = {
301 .attr = {.name = "max_segments", .mode = S_IRUGO },
302 .show = queue_max_segments_show,
303};
304
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200305static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
306 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
307 .show = queue_max_integrity_segments_show,
308};
309
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500310static struct queue_sysfs_entry queue_max_segment_size_entry = {
311 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
312 .show = queue_max_segment_size_show,
313};
314
Jens Axboe8324aa92008-01-29 14:51:59 +0100315static struct queue_sysfs_entry queue_iosched_entry = {
316 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
317 .show = elv_iosched_show,
318 .store = elv_iosched_store,
319};
320
Martin K. Petersene68b9032008-01-29 19:14:08 +0100321static struct queue_sysfs_entry queue_hw_sector_size_entry = {
322 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
Martin K. Petersene1defc42009-05-22 17:17:49 -0400323 .show = queue_logical_block_size_show,
324};
325
326static struct queue_sysfs_entry queue_logical_block_size_entry = {
327 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
328 .show = queue_logical_block_size_show,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100329};
330
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400331static struct queue_sysfs_entry queue_physical_block_size_entry = {
332 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
333 .show = queue_physical_block_size_show,
334};
335
336static struct queue_sysfs_entry queue_io_min_entry = {
337 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
338 .show = queue_io_min_show,
339};
340
341static struct queue_sysfs_entry queue_io_opt_entry = {
342 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
343 .show = queue_io_opt_show,
Jens Axboe8324aa92008-01-29 14:51:59 +0100344};
345
Martin K. Petersen86b37282009-11-10 11:50:21 +0100346static struct queue_sysfs_entry queue_discard_granularity_entry = {
347 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
348 .show = queue_discard_granularity_show,
349};
350
351static struct queue_sysfs_entry queue_discard_max_entry = {
352 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
353 .show = queue_discard_max_show,
354};
355
Martin K. Petersen98262f22009-12-03 09:24:48 +0100356static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
357 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
358 .show = queue_discard_zeroes_data_show,
359};
360
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100361static struct queue_sysfs_entry queue_nonrot_entry = {
362 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200363 .show = queue_show_nonrot,
364 .store = queue_store_nonrot,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100365};
366
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200367static struct queue_sysfs_entry queue_nomerges_entry = {
368 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
369 .show = queue_nomerges_show,
370 .store = queue_nomerges_store,
371};
372
Jens Axboec7c22e42008-09-13 20:26:01 +0200373static struct queue_sysfs_entry queue_rq_affinity_entry = {
374 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
375 .show = queue_rq_affinity_show,
376 .store = queue_rq_affinity_store,
377};
378
Jens Axboebc58ba92009-01-23 10:54:44 +0100379static struct queue_sysfs_entry queue_iostats_entry = {
380 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200381 .show = queue_show_iostats,
382 .store = queue_store_iostats,
Jens Axboebc58ba92009-01-23 10:54:44 +0100383};
384
Jens Axboee2e1a142010-06-09 10:42:09 +0200385static struct queue_sysfs_entry queue_random_entry = {
386 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200387 .show = queue_show_random,
388 .store = queue_store_random,
Jens Axboee2e1a142010-06-09 10:42:09 +0200389};
390
Jens Axboe8324aa92008-01-29 14:51:59 +0100391static struct attribute *default_attrs[] = {
392 &queue_requests_entry.attr,
393 &queue_ra_entry.attr,
394 &queue_max_hw_sectors_entry.attr,
395 &queue_max_sectors_entry.attr,
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500396 &queue_max_segments_entry.attr,
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200397 &queue_max_integrity_segments_entry.attr,
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500398 &queue_max_segment_size_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100399 &queue_iosched_entry.attr,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100400 &queue_hw_sector_size_entry.attr,
Martin K. Petersene1defc42009-05-22 17:17:49 -0400401 &queue_logical_block_size_entry.attr,
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400402 &queue_physical_block_size_entry.attr,
403 &queue_io_min_entry.attr,
404 &queue_io_opt_entry.attr,
Martin K. Petersen86b37282009-11-10 11:50:21 +0100405 &queue_discard_granularity_entry.attr,
406 &queue_discard_max_entry.attr,
Martin K. Petersen98262f22009-12-03 09:24:48 +0100407 &queue_discard_zeroes_data_entry.attr,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100408 &queue_nonrot_entry.attr,
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200409 &queue_nomerges_entry.attr,
Jens Axboec7c22e42008-09-13 20:26:01 +0200410 &queue_rq_affinity_entry.attr,
Jens Axboebc58ba92009-01-23 10:54:44 +0100411 &queue_iostats_entry.attr,
Jens Axboee2e1a142010-06-09 10:42:09 +0200412 &queue_random_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100413 NULL,
414};
415
416#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
417
418static ssize_t
419queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
420{
421 struct queue_sysfs_entry *entry = to_queue(attr);
422 struct request_queue *q =
423 container_of(kobj, struct request_queue, kobj);
424 ssize_t res;
425
426 if (!entry->show)
427 return -EIO;
428 mutex_lock(&q->sysfs_lock);
Tejun Heo34f60552011-12-14 00:33:37 +0100429 if (blk_queue_dead(q)) {
Jens Axboe8324aa92008-01-29 14:51:59 +0100430 mutex_unlock(&q->sysfs_lock);
431 return -ENOENT;
432 }
433 res = entry->show(q, page);
434 mutex_unlock(&q->sysfs_lock);
435 return res;
436}
437
438static ssize_t
439queue_attr_store(struct kobject *kobj, struct attribute *attr,
440 const char *page, size_t length)
441{
442 struct queue_sysfs_entry *entry = to_queue(attr);
Jens Axboe6728cb02008-01-31 13:03:55 +0100443 struct request_queue *q;
Jens Axboe8324aa92008-01-29 14:51:59 +0100444 ssize_t res;
445
446 if (!entry->store)
447 return -EIO;
Jens Axboe6728cb02008-01-31 13:03:55 +0100448
449 q = container_of(kobj, struct request_queue, kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100450 mutex_lock(&q->sysfs_lock);
Tejun Heo34f60552011-12-14 00:33:37 +0100451 if (blk_queue_dead(q)) {
Jens Axboe8324aa92008-01-29 14:51:59 +0100452 mutex_unlock(&q->sysfs_lock);
453 return -ENOENT;
454 }
455 res = entry->store(q, page, length);
456 mutex_unlock(&q->sysfs_lock);
457 return res;
458}
459
460/**
Andrew Morton499337b2011-09-21 10:01:22 +0200461 * blk_release_queue: - release a &struct request_queue when it is no longer needed
462 * @kobj: the kobj belonging to the request queue to be released
Jens Axboe8324aa92008-01-29 14:51:59 +0100463 *
464 * Description:
Andrew Morton499337b2011-09-21 10:01:22 +0200465 * blk_release_queue is the pair to blk_init_queue() or
Jens Axboe8324aa92008-01-29 14:51:59 +0100466 * blk_queue_make_request(). It should be called when a request queue is
467 * being released; typically when a block device is being de-registered.
468 * Currently, its primary task it to free all the &struct request
469 * structures that were allocated to the queue and the queue itself.
470 *
471 * Caveat:
472 * Hopefully the low level driver will have finished any
473 * outstanding requests first...
474 **/
475static void blk_release_queue(struct kobject *kobj)
476{
477 struct request_queue *q =
478 container_of(kobj, struct request_queue, kobj);
479 struct request_list *rl = &q->rq;
480
481 blk_sync_queue(q);
482
Tejun Heoe8989fa2012-03-05 13:15:20 -0800483 blkcg_exit_queue(q);
484
Tejun Heo7e5a8792011-12-14 00:33:42 +0100485 if (q->elevator) {
486 spin_lock_irq(q->queue_lock);
487 ioc_clear_queue(q);
488 spin_unlock_irq(q->queue_lock);
Hannes Reinecke777eb1b2011-09-28 08:07:01 -0600489 elevator_exit(q->elevator);
Tejun Heo7e5a8792011-12-14 00:33:42 +0100490 }
Hannes Reinecke777eb1b2011-09-28 08:07:01 -0600491
Jens Axboe8324aa92008-01-29 14:51:59 +0100492 if (rl->rq_pool)
493 mempool_destroy(rl->rq_pool);
494
495 if (q->queue_tags)
496 __blk_queue_free_tags(q);
497
498 blk_trace_shutdown(q);
499
500 bdi_destroy(&q->backing_dev_info);
Tejun Heoa73f7302011-12-14 00:33:37 +0100501
502 ida_simple_remove(&blk_queue_ida, q->id);
Jens Axboe8324aa92008-01-29 14:51:59 +0100503 kmem_cache_free(blk_requestq_cachep, q);
504}
505
Emese Revfy52cf25d2010-01-19 02:58:23 +0100506static const struct sysfs_ops queue_sysfs_ops = {
Jens Axboe8324aa92008-01-29 14:51:59 +0100507 .show = queue_attr_show,
508 .store = queue_attr_store,
509};
510
511struct kobj_type blk_queue_ktype = {
512 .sysfs_ops = &queue_sysfs_ops,
513 .default_attrs = default_attrs,
514 .release = blk_release_queue,
515};
516
517int blk_register_queue(struct gendisk *disk)
518{
519 int ret;
Li Zefan1d54ad62009-04-14 14:00:05 +0800520 struct device *dev = disk_to_dev(disk);
Jens Axboe8324aa92008-01-29 14:51:59 +0100521 struct request_queue *q = disk->queue;
522
Akinobu Mitafb199742008-04-21 09:51:06 +0200523 if (WARN_ON(!q))
Jens Axboe8324aa92008-01-29 14:51:59 +0100524 return -ENXIO;
525
Li Zefan1d54ad62009-04-14 14:00:05 +0800526 ret = blk_trace_init_sysfs(dev);
527 if (ret)
528 return ret;
529
Linus Torvaldsc9059592009-06-11 10:52:27 -0700530 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
Liu Yuaned5302d2011-04-19 13:47:58 +0200531 if (ret < 0) {
532 blk_trace_remove_sysfs(dev);
Jens Axboe8324aa92008-01-29 14:51:59 +0100533 return ret;
Liu Yuaned5302d2011-04-19 13:47:58 +0200534 }
Jens Axboe8324aa92008-01-29 14:51:59 +0100535
536 kobject_uevent(&q->kobj, KOBJ_ADD);
537
Martin K. Petersencd43e262009-05-22 17:17:52 -0400538 if (!q->request_fn)
539 return 0;
540
Jens Axboe8324aa92008-01-29 14:51:59 +0100541 ret = elv_register_queue(q);
542 if (ret) {
543 kobject_uevent(&q->kobj, KOBJ_REMOVE);
544 kobject_del(&q->kobj);
Liu Yuan80656b62011-04-13 22:14:54 +0200545 blk_trace_remove_sysfs(dev);
Xiaotian Fengc87ffbb2010-08-23 12:30:29 +0200546 kobject_put(&dev->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100547 return ret;
548 }
549
550 return 0;
551}
552
553void blk_unregister_queue(struct gendisk *disk)
554{
555 struct request_queue *q = disk->queue;
556
Akinobu Mitafb199742008-04-21 09:51:06 +0200557 if (WARN_ON(!q))
558 return;
559
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +0200560 if (q->request_fn)
Jens Axboe8324aa92008-01-29 14:51:59 +0100561 elv_unregister_queue(q);
562
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +0200563 kobject_uevent(&q->kobj, KOBJ_REMOVE);
564 kobject_del(&q->kobj);
565 blk_trace_remove_sysfs(disk_to_dev(disk));
566 kobject_put(&disk_to_dev(disk)->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100567}