hwmon: (coretemp) Fix cpu model output
[linux-2.6.git] / block / blk-sysfs.c
1 /*
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
12 struct 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
18 static ssize_t
19 queue_var_show(unsigned long var, char *page)
20 {
21         return sprintf(page, "%lu\n", var);
22 }
23
24 static ssize_t
25 queue_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
33 static ssize_t queue_requests_show(struct request_queue *q, char *page)
34 {
35         return queue_var_show(q->nr_requests, (page));
36 }
37
38 static ssize_t
39 queue_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;
44
45         if (!q->request_fn)
46                 return -EINVAL;
47
48         ret = queue_var_store(&nr, page, count);
49         if (nr < BLKDEV_MIN_RQ)
50                 nr = BLKDEV_MIN_RQ;
51
52         spin_lock_irq(q->queue_lock);
53         q->nr_requests = nr;
54         blk_queue_congestion_threshold(q);
55
56         if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
57                 blk_set_queue_congested(q, BLK_RW_SYNC);
58         else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
59                 blk_clear_queue_congested(q, BLK_RW_SYNC);
60
61         if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
62                 blk_set_queue_congested(q, BLK_RW_ASYNC);
63         else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
64                 blk_clear_queue_congested(q, BLK_RW_ASYNC);
65
66         if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
67                 blk_set_queue_full(q, BLK_RW_SYNC);
68         } else if (rl->count[BLK_RW_SYNC]+1 <= q->nr_requests) {
69                 blk_clear_queue_full(q, BLK_RW_SYNC);
70                 wake_up(&rl->wait[BLK_RW_SYNC]);
71         }
72
73         if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
74                 blk_set_queue_full(q, BLK_RW_ASYNC);
75         } else if (rl->count[BLK_RW_ASYNC]+1 <= q->nr_requests) {
76                 blk_clear_queue_full(q, BLK_RW_ASYNC);
77                 wake_up(&rl->wait[BLK_RW_ASYNC]);
78         }
79         spin_unlock_irq(q->queue_lock);
80         return ret;
81 }
82
83 static ssize_t queue_ra_show(struct request_queue *q, char *page)
84 {
85         unsigned long ra_kb = q->backing_dev_info.ra_pages <<
86                                         (PAGE_CACHE_SHIFT - 10);
87
88         return queue_var_show(ra_kb, (page));
89 }
90
91 static ssize_t
92 queue_ra_store(struct request_queue *q, const char *page, size_t count)
93 {
94         unsigned long ra_kb;
95         ssize_t ret = queue_var_store(&ra_kb, page, count);
96
97         q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
98
99         return ret;
100 }
101
102 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
103 {
104         int max_sectors_kb = queue_max_sectors(q) >> 1;
105
106         return queue_var_show(max_sectors_kb, (page));
107 }
108
109 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
110 {
111         return queue_var_show(queue_logical_block_size(q), page);
112 }
113
114 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
115 {
116         return queue_var_show(queue_physical_block_size(q), page);
117 }
118
119 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
120 {
121         return queue_var_show(queue_io_min(q), page);
122 }
123
124 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
125 {
126         return queue_var_show(queue_io_opt(q), page);
127 }
128
129 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
130 {
131         return queue_var_show(q->limits.discard_granularity, page);
132 }
133
134 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
135 {
136         return queue_var_show(q->limits.max_discard_sectors << 9, page);
137 }
138
139 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
140 {
141         return queue_var_show(queue_discard_zeroes_data(q), page);
142 }
143
144 static ssize_t
145 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
146 {
147         unsigned long max_sectors_kb,
148                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
149                         page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
150         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
151
152         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
153                 return -EINVAL;
154
155         spin_lock_irq(q->queue_lock);
156         q->limits.max_sectors = max_sectors_kb << 1;
157         spin_unlock_irq(q->queue_lock);
158
159         return ret;
160 }
161
162 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
163 {
164         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
165
166         return queue_var_show(max_hw_sectors_kb, (page));
167 }
168
169 static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
170 {
171         return queue_var_show(!blk_queue_nonrot(q), page);
172 }
173
174 static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
175                                   size_t count)
176 {
177         unsigned long nm;
178         ssize_t ret = queue_var_store(&nm, page, count);
179
180         spin_lock_irq(q->queue_lock);
181         if (nm)
182                 queue_flag_clear(QUEUE_FLAG_NONROT, q);
183         else
184                 queue_flag_set(QUEUE_FLAG_NONROT, q);
185         spin_unlock_irq(q->queue_lock);
186
187         return ret;
188 }
189
190 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
191 {
192         return queue_var_show((blk_queue_nomerges(q) << 1) |
193                                blk_queue_noxmerges(q), page);
194 }
195
196 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
197                                     size_t count)
198 {
199         unsigned long nm;
200         ssize_t ret = queue_var_store(&nm, page, count);
201
202         spin_lock_irq(q->queue_lock);
203         queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
204         queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
205         if (nm == 2)
206                 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
207         else if (nm)
208                 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
209         spin_unlock_irq(q->queue_lock);
210
211         return ret;
212 }
213
214 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
215 {
216         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
217
218         return queue_var_show(set, page);
219 }
220
221 static ssize_t
222 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
223 {
224         ssize_t ret = -EINVAL;
225 #if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
226         unsigned long val;
227
228         ret = queue_var_store(&val, page, count);
229         spin_lock_irq(q->queue_lock);
230         if (val)
231                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
232         else
233                 queue_flag_clear(QUEUE_FLAG_SAME_COMP,  q);
234         spin_unlock_irq(q->queue_lock);
235 #endif
236         return ret;
237 }
238
239 static ssize_t queue_iostats_show(struct request_queue *q, char *page)
240 {
241         return queue_var_show(blk_queue_io_stat(q), page);
242 }
243
244 static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
245                                    size_t count)
246 {
247         unsigned long stats;
248         ssize_t ret = queue_var_store(&stats, page, count);
249
250         spin_lock_irq(q->queue_lock);
251         if (stats)
252                 queue_flag_set(QUEUE_FLAG_IO_STAT, q);
253         else
254                 queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
255         spin_unlock_irq(q->queue_lock);
256
257         return ret;
258 }
259
260 static struct queue_sysfs_entry queue_requests_entry = {
261         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
262         .show = queue_requests_show,
263         .store = queue_requests_store,
264 };
265
266 static struct queue_sysfs_entry queue_ra_entry = {
267         .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
268         .show = queue_ra_show,
269         .store = queue_ra_store,
270 };
271
272 static struct queue_sysfs_entry queue_max_sectors_entry = {
273         .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
274         .show = queue_max_sectors_show,
275         .store = queue_max_sectors_store,
276 };
277
278 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
279         .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
280         .show = queue_max_hw_sectors_show,
281 };
282
283 static struct queue_sysfs_entry queue_iosched_entry = {
284         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
285         .show = elv_iosched_show,
286         .store = elv_iosched_store,
287 };
288
289 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
290         .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
291         .show = queue_logical_block_size_show,
292 };
293
294 static struct queue_sysfs_entry queue_logical_block_size_entry = {
295         .attr = {.name = "logical_block_size", .mode = S_IRUGO },
296         .show = queue_logical_block_size_show,
297 };
298
299 static struct queue_sysfs_entry queue_physical_block_size_entry = {
300         .attr = {.name = "physical_block_size", .mode = S_IRUGO },
301         .show = queue_physical_block_size_show,
302 };
303
304 static struct queue_sysfs_entry queue_io_min_entry = {
305         .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
306         .show = queue_io_min_show,
307 };
308
309 static struct queue_sysfs_entry queue_io_opt_entry = {
310         .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
311         .show = queue_io_opt_show,
312 };
313
314 static struct queue_sysfs_entry queue_discard_granularity_entry = {
315         .attr = {.name = "discard_granularity", .mode = S_IRUGO },
316         .show = queue_discard_granularity_show,
317 };
318
319 static struct queue_sysfs_entry queue_discard_max_entry = {
320         .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
321         .show = queue_discard_max_show,
322 };
323
324 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
325         .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
326         .show = queue_discard_zeroes_data_show,
327 };
328
329 static struct queue_sysfs_entry queue_nonrot_entry = {
330         .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
331         .show = queue_nonrot_show,
332         .store = queue_nonrot_store,
333 };
334
335 static struct queue_sysfs_entry queue_nomerges_entry = {
336         .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
337         .show = queue_nomerges_show,
338         .store = queue_nomerges_store,
339 };
340
341 static struct queue_sysfs_entry queue_rq_affinity_entry = {
342         .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
343         .show = queue_rq_affinity_show,
344         .store = queue_rq_affinity_store,
345 };
346
347 static struct queue_sysfs_entry queue_iostats_entry = {
348         .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
349         .show = queue_iostats_show,
350         .store = queue_iostats_store,
351 };
352
353 static struct attribute *default_attrs[] = {
354         &queue_requests_entry.attr,
355         &queue_ra_entry.attr,
356         &queue_max_hw_sectors_entry.attr,
357         &queue_max_sectors_entry.attr,
358         &queue_iosched_entry.attr,
359         &queue_hw_sector_size_entry.attr,
360         &queue_logical_block_size_entry.attr,
361         &queue_physical_block_size_entry.attr,
362         &queue_io_min_entry.attr,
363         &queue_io_opt_entry.attr,
364         &queue_discard_granularity_entry.attr,
365         &queue_discard_max_entry.attr,
366         &queue_discard_zeroes_data_entry.attr,
367         &queue_nonrot_entry.attr,
368         &queue_nomerges_entry.attr,
369         &queue_rq_affinity_entry.attr,
370         &queue_iostats_entry.attr,
371         NULL,
372 };
373
374 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
375
376 static ssize_t
377 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
378 {
379         struct queue_sysfs_entry *entry = to_queue(attr);
380         struct request_queue *q =
381                 container_of(kobj, struct request_queue, kobj);
382         ssize_t res;
383
384         if (!entry->show)
385                 return -EIO;
386         mutex_lock(&q->sysfs_lock);
387         if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
388                 mutex_unlock(&q->sysfs_lock);
389                 return -ENOENT;
390         }
391         res = entry->show(q, page);
392         mutex_unlock(&q->sysfs_lock);
393         return res;
394 }
395
396 static ssize_t
397 queue_attr_store(struct kobject *kobj, struct attribute *attr,
398                     const char *page, size_t length)
399 {
400         struct queue_sysfs_entry *entry = to_queue(attr);
401         struct request_queue *q;
402         ssize_t res;
403
404         if (!entry->store)
405                 return -EIO;
406
407         q = container_of(kobj, struct request_queue, kobj);
408         mutex_lock(&q->sysfs_lock);
409         if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
410                 mutex_unlock(&q->sysfs_lock);
411                 return -ENOENT;
412         }
413         res = entry->store(q, page, length);
414         mutex_unlock(&q->sysfs_lock);
415         return res;
416 }
417
418 /**
419  * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
420  * @kobj:    the kobj belonging of the request queue to be released
421  *
422  * Description:
423  *     blk_cleanup_queue is the pair to blk_init_queue() or
424  *     blk_queue_make_request().  It should be called when a request queue is
425  *     being released; typically when a block device is being de-registered.
426  *     Currently, its primary task it to free all the &struct request
427  *     structures that were allocated to the queue and the queue itself.
428  *
429  * Caveat:
430  *     Hopefully the low level driver will have finished any
431  *     outstanding requests first...
432  **/
433 static void blk_release_queue(struct kobject *kobj)
434 {
435         struct request_queue *q =
436                 container_of(kobj, struct request_queue, kobj);
437         struct request_list *rl = &q->rq;
438
439         blk_sync_queue(q);
440
441         if (rl->rq_pool)
442                 mempool_destroy(rl->rq_pool);
443
444         if (q->queue_tags)
445                 __blk_queue_free_tags(q);
446
447         blk_trace_shutdown(q);
448
449         bdi_destroy(&q->backing_dev_info);
450         kmem_cache_free(blk_requestq_cachep, q);
451 }
452
453 static const struct sysfs_ops queue_sysfs_ops = {
454         .show   = queue_attr_show,
455         .store  = queue_attr_store,
456 };
457
458 struct kobj_type blk_queue_ktype = {
459         .sysfs_ops      = &queue_sysfs_ops,
460         .default_attrs  = default_attrs,
461         .release        = blk_release_queue,
462 };
463
464 int blk_register_queue(struct gendisk *disk)
465 {
466         int ret;
467         struct device *dev = disk_to_dev(disk);
468
469         struct request_queue *q = disk->queue;
470
471         if (WARN_ON(!q))
472                 return -ENXIO;
473
474         ret = blk_trace_init_sysfs(dev);
475         if (ret)
476                 return ret;
477
478         ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
479         if (ret < 0)
480                 return ret;
481
482         kobject_uevent(&q->kobj, KOBJ_ADD);
483
484         if (!q->request_fn)
485                 return 0;
486
487         ret = elv_register_queue(q);
488         if (ret) {
489                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
490                 kobject_del(&q->kobj);
491                 blk_trace_remove_sysfs(disk_to_dev(disk));
492                 return ret;
493         }
494
495         return 0;
496 }
497
498 void blk_unregister_queue(struct gendisk *disk)
499 {
500         struct request_queue *q = disk->queue;
501
502         if (WARN_ON(!q))
503                 return;
504
505         if (q->request_fn)
506                 elv_unregister_queue(q);
507
508         kobject_uevent(&q->kobj, KOBJ_REMOVE);
509         kobject_del(&q->kobj);
510         blk_trace_remove_sysfs(disk_to_dev(disk));
511         kobject_put(&disk_to_dev(disk)->kobj);
512 }