blob: d3aa2aadb3e0e7d18645a2eb9333698f4984263a [file] [log] [blame]
Jens Axboe8324aa92008-01-29 14:51:59 +01001/*
2 * Functions related to sysfs handling
3 */
4#include <linux/kernel.h>
5#include <linux/module.h>
6#include <linux/bio.h>
7#include <linux/blkdev.h>
8#include <linux/blktrace_api.h>
9
10#include "blk.h"
11
12struct queue_sysfs_entry {
13 struct attribute attr;
14 ssize_t (*show)(struct request_queue *, char *);
15 ssize_t (*store)(struct request_queue *, const char *, size_t);
16};
17
18static ssize_t
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080019queue_var_show(unsigned long var, char *page)
Jens Axboe8324aa92008-01-29 14:51:59 +010020{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080021 return sprintf(page, "%lu\n", var);
Jens Axboe8324aa92008-01-29 14:51:59 +010022}
23
24static ssize_t
25queue_var_store(unsigned long *var, const char *page, size_t count)
26{
27 char *p = (char *) page;
28
29 *var = simple_strtoul(p, &p, 10);
30 return count;
31}
32
33static ssize_t queue_requests_show(struct request_queue *q, char *page)
34{
35 return queue_var_show(q->nr_requests, (page));
36}
37
38static ssize_t
39queue_requests_store(struct request_queue *q, const char *page, size_t count)
40{
41 struct request_list *rl = &q->rq;
42 unsigned long nr;
43 int ret = queue_var_store(&nr, page, count);
44 if (nr < BLKDEV_MIN_RQ)
45 nr = BLKDEV_MIN_RQ;
46
47 spin_lock_irq(q->queue_lock);
48 q->nr_requests = nr;
49 blk_queue_congestion_threshold(q);
50
Jens Axboe1faa16d2009-04-06 14:48:01 +020051 if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
52 blk_set_queue_congested(q, BLK_RW_SYNC);
53 else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
54 blk_clear_queue_congested(q, BLK_RW_SYNC);
Jens Axboe8324aa92008-01-29 14:51:59 +010055
Jens Axboe1faa16d2009-04-06 14:48:01 +020056 if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
57 blk_set_queue_congested(q, BLK_RW_ASYNC);
58 else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
59 blk_clear_queue_congested(q, BLK_RW_ASYNC);
Jens Axboe8324aa92008-01-29 14:51:59 +010060
Jens Axboe1faa16d2009-04-06 14:48:01 +020061 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
62 blk_set_queue_full(q, BLK_RW_SYNC);
63 } else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
64 blk_clear_queue_full(q, BLK_RW_SYNC);
65 wake_up(&rl->wait[BLK_RW_SYNC]);
Jens Axboe8324aa92008-01-29 14:51:59 +010066 }
67
Jens Axboe1faa16d2009-04-06 14:48:01 +020068 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
69 blk_set_queue_full(q, BLK_RW_ASYNC);
70 } else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
71 blk_clear_queue_full(q, BLK_RW_ASYNC);
72 wake_up(&rl->wait[BLK_RW_ASYNC]);
Jens Axboe8324aa92008-01-29 14:51:59 +010073 }
74 spin_unlock_irq(q->queue_lock);
75 return ret;
76}
77
78static ssize_t queue_ra_show(struct request_queue *q, char *page)
79{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +080080 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
81 (PAGE_CACHE_SHIFT - 10);
Jens Axboe8324aa92008-01-29 14:51:59 +010082
83 return queue_var_show(ra_kb, (page));
84}
85
86static ssize_t
87queue_ra_store(struct request_queue *q, const char *page, size_t count)
88{
89 unsigned long ra_kb;
90 ssize_t ret = queue_var_store(&ra_kb, page, count);
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. Petersene1defc42009-05-22 17:17:49 -0400104static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
Martin K. Petersene68b9032008-01-29 19:14:08 +0100105{
Martin K. Petersene1defc42009-05-22 17:17:49 -0400106 return queue_var_show(queue_logical_block_size(q), page);
Martin K. Petersene68b9032008-01-29 19:14:08 +0100107}
108
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400109static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
110{
111 return queue_var_show(queue_physical_block_size(q), page);
112}
113
114static ssize_t queue_io_min_show(struct request_queue *q, char *page)
115{
116 return queue_var_show(queue_io_min(q), page);
117}
118
119static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
120{
121 return queue_var_show(queue_io_opt(q), page);
Jens Axboe8324aa92008-01-29 14:51:59 +0100122}
123
124static ssize_t
125queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
126{
127 unsigned long max_sectors_kb,
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400128 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
Jens Axboe8324aa92008-01-29 14:51:59 +0100129 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
130 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
131
132 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
133 return -EINVAL;
Wu Fengguang7c239512008-11-25 09:08:39 +0100134
Jens Axboe8324aa92008-01-29 14:51:59 +0100135 spin_lock_irq(q->queue_lock);
Nikanth Karthikesanc295fc02009-09-01 22:40:15 +0200136 q->limits.max_sectors = max_sectors_kb << 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100137 spin_unlock_irq(q->queue_lock);
138
139 return ret;
140}
141
142static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
143{
Martin K. Petersenae03bf62009-05-22 17:17:50 -0400144 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
Jens Axboe8324aa92008-01-29 14:51:59 +0100145
146 return queue_var_show(max_hw_sectors_kb, (page));
147}
148
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100149static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
150{
151 return queue_var_show(!blk_queue_nonrot(q), page);
152}
153
154static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
155 size_t count)
156{
157 unsigned long nm;
158 ssize_t ret = queue_var_store(&nm, page, count);
159
160 spin_lock_irq(q->queue_lock);
161 if (nm)
162 queue_flag_clear(QUEUE_FLAG_NONROT, q);
163 else
164 queue_flag_set(QUEUE_FLAG_NONROT, q);
165 spin_unlock_irq(q->queue_lock);
166
167 return ret;
168}
169
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200170static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
171{
172 return queue_var_show(blk_queue_nomerges(q), page);
173}
174
175static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
176 size_t count)
177{
178 unsigned long nm;
179 ssize_t ret = queue_var_store(&nm, page, count);
180
Jens Axboebf0f9702008-05-07 09:09:39 +0200181 spin_lock_irq(q->queue_lock);
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200182 if (nm)
Jens Axboebf0f9702008-05-07 09:09:39 +0200183 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200184 else
Jens Axboebf0f9702008-05-07 09:09:39 +0200185 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
Jens Axboebf0f9702008-05-07 09:09:39 +0200186 spin_unlock_irq(q->queue_lock);
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100187
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200188 return ret;
189}
190
Jens Axboec7c22e42008-09-13 20:26:01 +0200191static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
192{
Xiaotian Feng9cb308c2009-07-17 15:26:26 +0800193 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
Jens Axboec7c22e42008-09-13 20:26:01 +0200194
Xiaotian Feng9cb308c2009-07-17 15:26:26 +0800195 return queue_var_show(set, page);
Jens Axboec7c22e42008-09-13 20:26:01 +0200196}
197
198static ssize_t
199queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
200{
201 ssize_t ret = -EINVAL;
202#if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
203 unsigned long val;
204
205 ret = queue_var_store(&val, page, count);
206 spin_lock_irq(q->queue_lock);
207 if (val)
208 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
209 else
210 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
211 spin_unlock_irq(q->queue_lock);
212#endif
213 return ret;
214}
Jens Axboe8324aa92008-01-29 14:51:59 +0100215
Jens Axboebc58ba92009-01-23 10:54:44 +0100216static ssize_t queue_iostats_show(struct request_queue *q, char *page)
217{
218 return queue_var_show(blk_queue_io_stat(q), page);
219}
220
221static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
222 size_t count)
223{
224 unsigned long stats;
225 ssize_t ret = queue_var_store(&stats, page, count);
226
227 spin_lock_irq(q->queue_lock);
228 if (stats)
229 queue_flag_set(QUEUE_FLAG_IO_STAT, q);
230 else
231 queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
232 spin_unlock_irq(q->queue_lock);
233
234 return ret;
235}
236
Jens Axboe8324aa92008-01-29 14:51:59 +0100237static struct queue_sysfs_entry queue_requests_entry = {
238 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
239 .show = queue_requests_show,
240 .store = queue_requests_store,
241};
242
243static struct queue_sysfs_entry queue_ra_entry = {
244 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
245 .show = queue_ra_show,
246 .store = queue_ra_store,
247};
248
249static struct queue_sysfs_entry queue_max_sectors_entry = {
250 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
251 .show = queue_max_sectors_show,
252 .store = queue_max_sectors_store,
253};
254
255static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
256 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
257 .show = queue_max_hw_sectors_show,
258};
259
260static struct queue_sysfs_entry queue_iosched_entry = {
261 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
262 .show = elv_iosched_show,
263 .store = elv_iosched_store,
264};
265
Martin K. Petersene68b9032008-01-29 19:14:08 +0100266static struct queue_sysfs_entry queue_hw_sector_size_entry = {
267 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
Martin K. Petersene1defc42009-05-22 17:17:49 -0400268 .show = queue_logical_block_size_show,
269};
270
271static struct queue_sysfs_entry queue_logical_block_size_entry = {
272 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
273 .show = queue_logical_block_size_show,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100274};
275
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400276static struct queue_sysfs_entry queue_physical_block_size_entry = {
277 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
278 .show = queue_physical_block_size_show,
279};
280
281static struct queue_sysfs_entry queue_io_min_entry = {
282 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
283 .show = queue_io_min_show,
284};
285
286static struct queue_sysfs_entry queue_io_opt_entry = {
287 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
288 .show = queue_io_opt_show,
Jens Axboe8324aa92008-01-29 14:51:59 +0100289};
290
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100291static struct queue_sysfs_entry queue_nonrot_entry = {
292 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
293 .show = queue_nonrot_show,
294 .store = queue_nonrot_store,
295};
296
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200297static struct queue_sysfs_entry queue_nomerges_entry = {
298 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
299 .show = queue_nomerges_show,
300 .store = queue_nomerges_store,
301};
302
Jens Axboec7c22e42008-09-13 20:26:01 +0200303static struct queue_sysfs_entry queue_rq_affinity_entry = {
304 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
305 .show = queue_rq_affinity_show,
306 .store = queue_rq_affinity_store,
307};
308
Jens Axboebc58ba92009-01-23 10:54:44 +0100309static struct queue_sysfs_entry queue_iostats_entry = {
310 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
311 .show = queue_iostats_show,
312 .store = queue_iostats_store,
313};
314
Jens Axboe8324aa92008-01-29 14:51:59 +0100315static struct attribute *default_attrs[] = {
316 &queue_requests_entry.attr,
317 &queue_ra_entry.attr,
318 &queue_max_hw_sectors_entry.attr,
319 &queue_max_sectors_entry.attr,
320 &queue_iosched_entry.attr,
Martin K. Petersene68b9032008-01-29 19:14:08 +0100321 &queue_hw_sector_size_entry.attr,
Martin K. Petersene1defc42009-05-22 17:17:49 -0400322 &queue_logical_block_size_entry.attr,
Martin K. Petersenc72758f2009-05-22 17:17:53 -0400323 &queue_physical_block_size_entry.attr,
324 &queue_io_min_entry.attr,
325 &queue_io_opt_entry.attr,
Bartlomiej Zolnierkiewicz1308835f2009-01-07 12:22:39 +0100326 &queue_nonrot_entry.attr,
Alan D. Brunelleac9fafa2008-04-29 14:44:19 +0200327 &queue_nomerges_entry.attr,
Jens Axboec7c22e42008-09-13 20:26:01 +0200328 &queue_rq_affinity_entry.attr,
Jens Axboebc58ba92009-01-23 10:54:44 +0100329 &queue_iostats_entry.attr,
Jens Axboe8324aa92008-01-29 14:51:59 +0100330 NULL,
331};
332
333#define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
334
335static ssize_t
336queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
337{
338 struct queue_sysfs_entry *entry = to_queue(attr);
339 struct request_queue *q =
340 container_of(kobj, struct request_queue, kobj);
341 ssize_t res;
342
343 if (!entry->show)
344 return -EIO;
345 mutex_lock(&q->sysfs_lock);
346 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
347 mutex_unlock(&q->sysfs_lock);
348 return -ENOENT;
349 }
350 res = entry->show(q, page);
351 mutex_unlock(&q->sysfs_lock);
352 return res;
353}
354
355static ssize_t
356queue_attr_store(struct kobject *kobj, struct attribute *attr,
357 const char *page, size_t length)
358{
359 struct queue_sysfs_entry *entry = to_queue(attr);
Jens Axboe6728cb02008-01-31 13:03:55 +0100360 struct request_queue *q;
Jens Axboe8324aa92008-01-29 14:51:59 +0100361 ssize_t res;
362
363 if (!entry->store)
364 return -EIO;
Jens Axboe6728cb02008-01-31 13:03:55 +0100365
366 q = container_of(kobj, struct request_queue, kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100367 mutex_lock(&q->sysfs_lock);
368 if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
369 mutex_unlock(&q->sysfs_lock);
370 return -ENOENT;
371 }
372 res = entry->store(q, page, length);
373 mutex_unlock(&q->sysfs_lock);
374 return res;
375}
376
377/**
378 * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
379 * @kobj: the kobj belonging of the request queue to be released
380 *
381 * Description:
382 * blk_cleanup_queue is the pair to blk_init_queue() or
383 * blk_queue_make_request(). It should be called when a request queue is
384 * being released; typically when a block device is being de-registered.
385 * Currently, its primary task it to free all the &struct request
386 * structures that were allocated to the queue and the queue itself.
387 *
388 * Caveat:
389 * Hopefully the low level driver will have finished any
390 * outstanding requests first...
391 **/
392static void blk_release_queue(struct kobject *kobj)
393{
394 struct request_queue *q =
395 container_of(kobj, struct request_queue, kobj);
396 struct request_list *rl = &q->rq;
397
398 blk_sync_queue(q);
399
400 if (rl->rq_pool)
401 mempool_destroy(rl->rq_pool);
402
403 if (q->queue_tags)
404 __blk_queue_free_tags(q);
405
406 blk_trace_shutdown(q);
407
408 bdi_destroy(&q->backing_dev_info);
409 kmem_cache_free(blk_requestq_cachep, q);
410}
411
412static struct sysfs_ops queue_sysfs_ops = {
413 .show = queue_attr_show,
414 .store = queue_attr_store,
415};
416
417struct kobj_type blk_queue_ktype = {
418 .sysfs_ops = &queue_sysfs_ops,
419 .default_attrs = default_attrs,
420 .release = blk_release_queue,
421};
422
423int blk_register_queue(struct gendisk *disk)
424{
425 int ret;
Li Zefan1d54ad62009-04-14 14:00:05 +0800426 struct device *dev = disk_to_dev(disk);
Jens Axboe8324aa92008-01-29 14:51:59 +0100427
428 struct request_queue *q = disk->queue;
429
Akinobu Mitafb199742008-04-21 09:51:06 +0200430 if (WARN_ON(!q))
Jens Axboe8324aa92008-01-29 14:51:59 +0100431 return -ENXIO;
432
Li Zefan1d54ad62009-04-14 14:00:05 +0800433 ret = blk_trace_init_sysfs(dev);
434 if (ret)
435 return ret;
436
Linus Torvaldsc9059592009-06-11 10:52:27 -0700437 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
Jens Axboe8324aa92008-01-29 14:51:59 +0100438 if (ret < 0)
439 return ret;
440
441 kobject_uevent(&q->kobj, KOBJ_ADD);
442
Martin K. Petersencd43e262009-05-22 17:17:52 -0400443 if (!q->request_fn)
444 return 0;
445
Jens Axboe8324aa92008-01-29 14:51:59 +0100446 ret = elv_register_queue(q);
447 if (ret) {
448 kobject_uevent(&q->kobj, KOBJ_REMOVE);
449 kobject_del(&q->kobj);
450 return ret;
451 }
452
453 return 0;
454}
455
456void blk_unregister_queue(struct gendisk *disk)
457{
458 struct request_queue *q = disk->queue;
459
Akinobu Mitafb199742008-04-21 09:51:06 +0200460 if (WARN_ON(!q))
461 return;
462
463 if (q->request_fn) {
Jens Axboe8324aa92008-01-29 14:51:59 +0100464 elv_unregister_queue(q);
465
466 kobject_uevent(&q->kobj, KOBJ_REMOVE);
467 kobject_del(&q->kobj);
Tejun Heoed9e1982008-08-25 19:56:05 +0900468 kobject_put(&disk_to_dev(disk)->kobj);
Jens Axboe8324aa92008-01-29 14:51:59 +0100469 }
470}