blob: 45c56d86b8265ad84e840ad363e2c408356285ae [file] [log] [blame]
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"
12
13struct queue_sysfs_entry {
14 struct attribute attr;
15 ssize_t (*show)(struct request_queue *, char *);
16 ssize_t (*store)(struct request_queue *, const char *, size_t);
17};
18
19static ssize_t
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080020queue_var_show(unsigned long var, char *page)
Jens Axboe8324aa92008-01-29 14:51:59 +010021{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080022 return sprintf(page, "%lu\n", var);
Jens Axboe8324aa92008-01-29 14:51:59 +010023}
24
25static ssize_t
26queue_var_store(unsigned long *var, const char *page, size_t count)
27{
28 char *p = (char *) page;
29
30 *var = simple_strtoul(p, &p, 10);
31 return count;
32}
33
34static ssize_t queue_requests_show(struct request_queue *q, char *page)
35{
36 return queue_var_show(q->nr_requests, (page));
37}
38
39static ssize_t
40queue_requests_store(struct request_queue *q, const char *page, size_t count)
41{
42 struct request_list *rl = &q->rq;
43 unsigned long nr;
Jens Axboeb8a9ae72009-09-11 22:44:29 +020044 int ret;
45
46 if (!q->request_fn)
47 return -EINVAL;
48
49 ret = queue_var_store(&nr, page, count);
Jens Axboe8324aa92008-01-29 14:51:59 +010050 if (nr < BLKDEV_MIN_RQ)
51 nr = BLKDEV_MIN_RQ;
52
53 spin_lock_irq(q->queue_lock);
54 q->nr_requests = nr;
55 blk_queue_congestion_threshold(q);
56
Jens Axboe1faa16d2009-04-06 14:48:01 +020057 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
58 blk_set_queue_congested(q, BLK_RW_SYNC);
59 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
60 blk_clear_queue_congested(q, BLK_RW_SYNC);
Jens Axboe8324aa92008-01-29 14:51:59 +010061
Jens Axboe1faa16d2009-04-06 14:48:01 +020062 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
63 blk_set_queue_congested(q, BLK_RW_ASYNC);
64 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
65 blk_clear_queue_congested(q, BLK_RW_ASYNC);
Jens Axboe8324aa92008-01-29 14:51:59 +010066
Jens Axboe1faa16d2009-04-06 14:48:01 +020067 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
68 blk_set_queue_full(q, BLK_RW_SYNC);
Tao Ma60735b62011-04-19 13:50:40 +020069 } else {
Jens Axboe1faa16d2009-04-06 14:48:01 +020070 blk_clear_queue_full(q, BLK_RW_SYNC);
71 wake_up(&rl->wait[BLK_RW_SYNC]);
Jens Axboe8324aa92008-01-29 14:51:59 +010072 }
73
Jens Axboe1faa16d2009-04-06 14:48:01 +020074 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
75 blk_set_queue_full(q, BLK_RW_ASYNC);
Tao Ma60735b62011-04-19 13:50:40 +020076 } else {
Jens Axboe1faa16d2009-04-06 14:48:01 +020077 blk_clear_queue_full(q, BLK_RW_ASYNC);
78 wake_up(&rl->wait[BLK_RW_ASYNC]);
Jens Axboe8324aa92008-01-29 14:51:59 +010079 }
80 spin_unlock_irq(q->queue_lock);
81 return ret;
82}
83
84static ssize_t queue_ra_show(struct request_queue *q, char *page)
85{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080086 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
87 (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +010088
89 return queue_var_show(ra_kb, (page));
90}
91
92static ssize_t
93queue_ra_store(struct request_queue *q, const char *page, size_t count)
94{
95 unsigned long ra_kb;
96 ssize_t ret = queue_var_store(&ra_kb, page, count);
97
Jens Axboe8324aa92008-01-29 14:51:59 +010098 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +010099
100 return ret;
101}
102
103static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
104{
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400105 int max_sectors_kb = queue_max_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100106
107 return queue_var_show(max_sectors_kb, (page));
108}
109
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500110static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
111{
112 return queue_var_show(queue_max_segments(q), (page));
113}
114
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200115static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
116{
117 return queue_var_show(q->limits.max_integrity_segments, (page));
118}
119
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500120static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
121{
Martin K. Petersene692cb62010-12-01 19:41:49 +0100122 if (blk_queue_cluster(q))
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500123 return queue_var_show(queue_max_segment_size(q), (page));
124
125 return queue_var_show(PAGE_CACHE_SIZE, (page));
126}
127
Martin K. Petersene1defc42009-05-22 17:17:49 -0400128static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
Martin K. Petersene68b9032008-01-29 19:14:08 +0100129{
Martin K. Petersene1defc42009-05-22 17:17:49 -0400130 return queue_var_show(queue_logical_block_size(q), page);
Martin K. Petersene68b9032008-01-29 19:14:08 +0100131}
132
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400133static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
134{
135 return queue_var_show(queue_physical_block_size(q), page);
136}
137
138static ssize_t queue_io_min_show(struct request_queue *q, char *page)
139{
140 return queue_var_show(queue_io_min(q), page);
141}
142
143static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
144{
145 return queue_var_show(queue_io_opt(q), page);
Jens Axboe8324aa92008-01-29 14:51:59 +0100146}
147
Martin K. Petersen86b37282009-11-10 11:50:21 +0100148static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
149{
150 return queue_var_show(q->limits.discard_granularity, page);
151}
152
153static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
154{
Martin K. Petersena934a002011-05-18 10:37:35 +0200155 return sprintf(page, "%llu\n",
156 (unsigned long long)q->limits.max_discard_sectors << 9);
Martin K. Petersen86b37282009-11-10 11:50:21 +0100157}
158
Martin K. Petersen98262f22009-12-03 09:24:48 +0100159static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
160{
161 return queue_var_show(queue_discard_zeroes_data(q), page);
162}
163
Jens Axboe8324aa92008-01-29 14:51:59 +0100164static ssize_t
165queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
166{
167 unsigned long max_sectors_kb,
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400168 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
Jens Axboe8324aa92008-01-29 14:51:59 +0100169 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
170 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
171
172 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
173 return -EINVAL;
Wu Fengguang7c239512008-11-25 09:08:39 +0100174
Jens Axboe8324aa92008-01-29 14:51:59 +0100175 spin_lock_irq(q->queue_lock);
Nikanth Karthikesanc295fc02009-09-01 22:40:15 +0200176 q->limits.max_sectors = max_sectors_kb << 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100177 spin_unlock_irq(q->queue_lock);
178
179 return ret;
180}
181
182static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
183{
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400184 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100185
186 return queue_var_show(max_hw_sectors_kb, (page));
187}
188
Jens Axboe956bcb72010-08-07 18:13:50 +0200189#define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
190static ssize_t \
191queue_show_##name(struct request_queue *q, char *page) \
192{ \
193 int bit; \
194 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
195 return queue_var_show(neg ? !bit : bit, page); \
196} \
197static ssize_t \
198queue_store_##name(struct request_queue *q, const char *page, size_t count) \
199{ \
200 unsigned long val; \
201 ssize_t ret; \
202 ret = queue_var_store(&val, page, count); \
203 if (neg) \
204 val = !val; \
205 \
206 spin_lock_irq(q->queue_lock); \
207 if (val) \
208 queue_flag_set(QUEUE_FLAG_##flag, q); \
209 else \
210 queue_flag_clear(QUEUE_FLAG_##flag, q); \
211 spin_unlock_irq(q->queue_lock); \
212 return ret; \
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100213}
214
Jens Axboe956bcb72010-08-07 18:13:50 +0200215QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
216QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
217QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
218#undef QUEUE_SYSFS_BIT_FNS
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100219
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200220static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
221{
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100222 return queue_var_show((blk_queue_nomerges(q) << 1) |
223 blk_queue_noxmerges(q), page);
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200224}
225
226static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
227 size_t count)
228{
229 unsigned long nm;
230 ssize_t ret = queue_var_store(&nm, page, count);
231
Jens Axboebf0f9702008-05-07 09:09:39 +0200232 spin_lock_irq(q->queue_lock);
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100233 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
234 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
235 if (nm == 2)
Jens Axboebf0f9702008-05-07 09:09:39 +0200236 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
Alan D. Brunelle488991e2010-01-29 09:04:08 +0100237 else if (nm)
238 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
Jens Axboebf0f9702008-05-07 09:09:39 +0200239 spin_unlock_irq(q->queue_lock);
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100240
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200241 return ret;
242}
243
Jens Axboec7c22e42008-09-13 20:26:01 +0200244static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
245{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +0800246 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
Jens Axboec7c22e42008-09-13 20:26:01 +0200247
Xiaotian Feng9cb308c2009-07-17 15:26:26 +0800248 return queue_var_show(set, page);
Jens Axboec7c22e42008-09-13 20:26:01 +0200249}
250
251static ssize_t
252queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
253{
254 ssize_t ret = -EINVAL;
255#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
256 unsigned long val;
257
258 ret = queue_var_store(&val, page, count);
259 spin_lock_irq(q->queue_lock);
260 if (val)
261 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
262 else
263 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
264 spin_unlock_irq(q->queue_lock);
265#endif
266 return ret;
267}
Jens Axboe8324aa92008-01-29 14:51:59 +0100268
269static struct queue_sysfs_entry queue_requests_entry = {
270 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
271 .show = queue_requests_show,
272 .store = queue_requests_store,
273};
274
275static struct queue_sysfs_entry queue_ra_entry = {
276 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
277 .show = queue_ra_show,
278 .store = queue_ra_store,
279};
280
281static struct queue_sysfs_entry queue_max_sectors_entry = {
282 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
283 .show = queue_max_sectors_show,
284 .store = queue_max_sectors_store,
285};
286
287static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
288 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
289 .show = queue_max_hw_sectors_show,
290};
291
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500292static struct queue_sysfs_entry queue_max_segments_entry = {
293 .attr = {.name = "max_segments", .mode = S_IRUGO },
294 .show = queue_max_segments_show,
295};
296
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200297static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
298 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
299 .show = queue_max_integrity_segments_show,
300};
301
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500302static struct queue_sysfs_entry queue_max_segment_size_entry = {
303 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
304 .show = queue_max_segment_size_show,
305};
306
Jens Axboe8324aa92008-01-29 14:51:59 +0100307static struct queue_sysfs_entry queue_iosched_entry = {
308 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
309 .show = elv_iosched_show,
310 .store = elv_iosched_store,
311};
312
Martin K. Petersene68b9032008-01-29 19:14:08 +0100313static struct queue_sysfs_entry queue_hw_sector_size_entry = {
314 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
Martin K. Petersene1defc42009-05-22 17:17:49 -0400315 .show = queue_logical_block_size_show,
316};
317
318static struct queue_sysfs_entry queue_logical_block_size_entry = {
319 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
320 .show = queue_logical_block_size_show,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100321};
322
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400323static struct queue_sysfs_entry queue_physical_block_size_entry = {
324 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
325 .show = queue_physical_block_size_show,
326};
327
328static struct queue_sysfs_entry queue_io_min_entry = {
329 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
330 .show = queue_io_min_show,
331};
332
333static struct queue_sysfs_entry queue_io_opt_entry = {
334 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
335 .show = queue_io_opt_show,
Jens Axboe8324aa92008-01-29 14:51:59 +0100336};
337
Martin K. Petersen86b37282009-11-10 11:50:21 +0100338static struct queue_sysfs_entry queue_discard_granularity_entry = {
339 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
340 .show = queue_discard_granularity_show,
341};
342
343static struct queue_sysfs_entry queue_discard_max_entry = {
344 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
345 .show = queue_discard_max_show,
346};
347
Martin K. Petersen98262f22009-12-03 09:24:48 +0100348static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
349 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
350 .show = queue_discard_zeroes_data_show,
351};
352
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100353static struct queue_sysfs_entry queue_nonrot_entry = {
354 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200355 .show = queue_show_nonrot,
356 .store = queue_store_nonrot,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100357};
358
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200359static struct queue_sysfs_entry queue_nomerges_entry = {
360 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
361 .show = queue_nomerges_show,
362 .store = queue_nomerges_store,
363};
364
Jens Axboec7c22e42008-09-13 20:26:01 +0200365static struct queue_sysfs_entry queue_rq_affinity_entry = {
366 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
367 .show = queue_rq_affinity_show,
368 .store = queue_rq_affinity_store,
369};
370
Jens Axboebc58ba92009-01-23 10:54:44 +0100371static struct queue_sysfs_entry queue_iostats_entry = {
372 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200373 .show = queue_show_iostats,
374 .store = queue_store_iostats,
Jens Axboebc58ba92009-01-23 10:54:44 +0100375};
376
Jens Axboee2e1a142010-06-09 10:42:09 +0200377static struct queue_sysfs_entry queue_random_entry = {
378 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
Jens Axboe956bcb72010-08-07 18:13:50 +0200379 .show = queue_show_random,
380 .store = queue_store_random,
Jens Axboee2e1a142010-06-09 10:42:09 +0200381};
382
Jens Axboe8324aa92008-01-29 14:51:59 +0100383static struct attribute *default_attrs[] = {
384 &queue_requests_entry.attr,
385 &queue_ra_entry.attr,
386 &queue_max_hw_sectors_entry.attr,
387 &queue_max_sectors_entry.attr,
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500388 &queue_max_segments_entry.attr,
Martin K. Petersen13f05c82010-09-10 20:50:10 +0200389 &queue_max_integrity_segments_entry.attr,
Martin K. Petersenc77a5712010-03-10 00:48:33 -0500390 &queue_max_segment_size_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100391 &queue_iosched_entry.attr,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100392 &queue_hw_sector_size_entry.attr,
Martin K. Petersene1defc42009-05-22 17:17:49 -0400393 &queue_logical_block_size_entry.attr,
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400394 &queue_physical_block_size_entry.attr,
395 &queue_io_min_entry.attr,
396 &queue_io_opt_entry.attr,
Martin K. Petersen86b37282009-11-10 11:50:21 +0100397 &queue_discard_granularity_entry.attr,
398 &queue_discard_max_entry.attr,
Martin K. Petersen98262f22009-12-03 09:24:48 +0100399 &queue_discard_zeroes_data_entry.attr,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100400 &queue_nonrot_entry.attr,
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200401 &queue_nomerges_entry.attr,
Jens Axboec7c22e42008-09-13 20:26:01 +0200402 &queue_rq_affinity_entry.attr,
Jens Axboebc58ba92009-01-23 10:54:44 +0100403 &queue_iostats_entry.attr,
Jens Axboee2e1a142010-06-09 10:42:09 +0200404 &queue_random_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100405 NULL,
406};
407
408#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
409
410static ssize_t
411queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
412{
413 struct queue_sysfs_entry *entry = to_queue(attr);
414 struct request_queue *q =
415 container_of(kobj, struct request_queue, kobj);
416 ssize_t res;
417
418 if (!entry->show)
419 return -EIO;
420 mutex_lock(&q->sysfs_lock);
421 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
422 mutex_unlock(&q->sysfs_lock);
423 return -ENOENT;
424 }
425 res = entry->show(q, page);
426 mutex_unlock(&q->sysfs_lock);
427 return res;
428}
429
430static ssize_t
431queue_attr_store(struct kobject *kobj, struct attribute *attr,
432 const char *page, size_t length)
433{
434 struct queue_sysfs_entry *entry = to_queue(attr);
Jens Axboe6728cb02008-01-31 13:03:55 +0100435 struct request_queue *q;
Jens Axboe8324aa92008-01-29 14:51:59 +0100436 ssize_t res;
437
438 if (!entry->store)
439 return -EIO;
Jens Axboe6728cb02008-01-31 13:03:55 +0100440
441 q = container_of(kobj, struct request_queue, kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100442 mutex_lock(&q->sysfs_lock);
443 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
444 mutex_unlock(&q->sysfs_lock);
445 return -ENOENT;
446 }
447 res = entry->store(q, page, length);
448 mutex_unlock(&q->sysfs_lock);
449 return res;
450}
451
452/**
453 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
454 * @kobj: the kobj belonging of the request queue to be released
455 *
456 * Description:
457 * blk_cleanup_queue is the pair to blk_init_queue() or
458 * blk_queue_make_request(). It should be called when a request queue is
459 * being released; typically when a block device is being de-registered.
460 * Currently, its primary task it to free all the &struct request
461 * structures that were allocated to the queue and the queue itself.
462 *
463 * Caveat:
464 * Hopefully the low level driver will have finished any
465 * outstanding requests first...
466 **/
467static void blk_release_queue(struct kobject *kobj)
468{
469 struct request_queue *q =
470 container_of(kobj, struct request_queue, kobj);
471 struct request_list *rl = &q->rq;
472
473 blk_sync_queue(q);
474
Hannes Reineckec2b387f2011-09-28 08:07:01 -0600475 if (q->elevator)
476 elevator_exit(q->elevator);
477
478 blk_throtl_exit(q);
479
Jens Axboe8324aa92008-01-29 14:51:59 +0100480 if (rl->rq_pool)
481 mempool_destroy(rl->rq_pool);
482
483 if (q->queue_tags)
484 __blk_queue_free_tags(q);
485
486 blk_trace_shutdown(q);
487
488 bdi_destroy(&q->backing_dev_info);
489 kmem_cache_free(blk_requestq_cachep, q);
490}
491
Emese Revfy52cf25d2010-01-19 02:58:23 +0100492static const struct sysfs_ops queue_sysfs_ops = {
Jens Axboe8324aa92008-01-29 14:51:59 +0100493 .show = queue_attr_show,
494 .store = queue_attr_store,
495};
496
497struct kobj_type blk_queue_ktype = {
498 .sysfs_ops = &queue_sysfs_ops,
499 .default_attrs = default_attrs,
500 .release = blk_release_queue,
501};
502
503int blk_register_queue(struct gendisk *disk)
504{
505 int ret;
Li Zefan1d54ad62009-04-14 14:00:05 +0800506 struct device *dev = disk_to_dev(disk);
Jens Axboe8324aa92008-01-29 14:51:59 +0100507 struct request_queue *q = disk->queue;
508
Akinobu Mitafb199742008-04-21 09:51:06 +0200509 if (WARN_ON(!q))
Jens Axboe8324aa92008-01-29 14:51:59 +0100510 return -ENXIO;
511
Li Zefan1d54ad62009-04-14 14:00:05 +0800512 ret = blk_trace_init_sysfs(dev);
513 if (ret)
514 return ret;
515
Linus Torvaldsc9059592009-06-11 10:52:27 -0700516 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
Liu Yuaned5302d2011-04-19 13:47:58 +0200517 if (ret < 0) {
518 blk_trace_remove_sysfs(dev);
Jens Axboe8324aa92008-01-29 14:51:59 +0100519 return ret;
Liu Yuaned5302d2011-04-19 13:47:58 +0200520 }
Jens Axboe8324aa92008-01-29 14:51:59 +0100521
522 kobject_uevent(&q->kobj, KOBJ_ADD);
523
Martin K. Petersencd43e262009-05-22 17:17:52 -0400524 if (!q->request_fn)
525 return 0;
526
Jens Axboe8324aa92008-01-29 14:51:59 +0100527 ret = elv_register_queue(q);
528 if (ret) {
529 kobject_uevent(&q->kobj, KOBJ_REMOVE);
530 kobject_del(&q->kobj);
Liu Yuan80656b62011-04-13 22:14:54 +0200531 blk_trace_remove_sysfs(dev);
Xiaotian Fengc87ffbb2010-08-23 12:30:29 +0200532 kobject_put(&dev->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100533 return ret;
534 }
535
536 return 0;
537}
538
539void blk_unregister_queue(struct gendisk *disk)
540{
541 struct request_queue *q = disk->queue;
542
Akinobu Mitafb199742008-04-21 09:51:06 +0200543 if (WARN_ON(!q))
544 return;
545
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +0200546 if (q->request_fn)
Jens Axboe8324aa92008-01-29 14:51:59 +0100547 elv_unregister_queue(q);
548
Zdenek Kabelac48c0d4d2009-09-25 06:19:26 +0200549 kobject_uevent(&q->kobj, KOBJ_REMOVE);
550 kobject_del(&q->kobj);
551 blk_trace_remove_sysfs(disk_to_dev(disk));
552 kobject_put(&disk_to_dev(disk)->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100553}