Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs
[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
130 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
131 {
132         unsigned long max_sectors_kb,
133                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
134                         page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
135         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
136
137         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
138                 return -EINVAL;
139
140         spin_lock_irq(q->queue_lock);
141         q->limits.max_sectors = max_sectors_kb << 1;
142         spin_unlock_irq(q->queue_lock);
143
144         return ret;
145 }
146
147 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
148 {
149         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
150
151         return queue_var_show(max_hw_sectors_kb, (page));
152 }
153
154 static ssize_t queue_nonrot_show(struct request_queue *q, char *page)
155 {
156         return queue_var_show(!blk_queue_nonrot(q), page);
157 }
158
159 static ssize_t queue_nonrot_store(struct request_queue *q, const char *page,
160                                   size_t count)
161 {
162         unsigned long nm;
163         ssize_t ret = queue_var_store(&nm, page, count);
164
165         spin_lock_irq(q->queue_lock);
166         if (nm)
167                 queue_flag_clear(QUEUE_FLAG_NONROT, q);
168         else
169                 queue_flag_set(QUEUE_FLAG_NONROT, q);
170         spin_unlock_irq(q->queue_lock);
171
172         return ret;
173 }
174
175 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
176 {
177         return queue_var_show(blk_queue_nomerges(q), page);
178 }
179
180 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
181                                     size_t count)
182 {
183         unsigned long nm;
184         ssize_t ret = queue_var_store(&nm, page, count);
185
186         spin_lock_irq(q->queue_lock);
187         if (nm)
188                 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
189         else
190                 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
191         spin_unlock_irq(q->queue_lock);
192
193         return ret;
194 }
195
196 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
197 {
198         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
199
200         return queue_var_show(set, page);
201 }
202
203 static ssize_t
204 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
205 {
206         ssize_t ret = -EINVAL;
207 #if defined(CONFIG_USE_GENERIC_SMP_HELPERS)
208         unsigned long val;
209
210         ret = queue_var_store(&val, page, count);
211         spin_lock_irq(q->queue_lock);
212         if (val)
213                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
214         else
215                 queue_flag_clear(QUEUE_FLAG_SAME_COMP,  q);
216         spin_unlock_irq(q->queue_lock);
217 #endif
218         return ret;
219 }
220
221 static ssize_t queue_iostats_show(struct request_queue *q, char *page)
222 {
223         return queue_var_show(blk_queue_io_stat(q), page);
224 }
225
226 static ssize_t queue_iostats_store(struct request_queue *q, const char *page,
227                                    size_t count)
228 {
229         unsigned long stats;
230         ssize_t ret = queue_var_store(&stats, page, count);
231
232         spin_lock_irq(q->queue_lock);
233         if (stats)
234                 queue_flag_set(QUEUE_FLAG_IO_STAT, q);
235         else
236                 queue_flag_clear(QUEUE_FLAG_IO_STAT, q);
237         spin_unlock_irq(q->queue_lock);
238
239         return ret;
240 }
241
242 static struct queue_sysfs_entry queue_requests_entry = {
243         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
244         .show = queue_requests_show,
245         .store = queue_requests_store,
246 };
247
248 static struct queue_sysfs_entry queue_ra_entry = {
249         .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
250         .show = queue_ra_show,
251         .store = queue_ra_store,
252 };
253
254 static struct queue_sysfs_entry queue_max_sectors_entry = {
255         .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
256         .show = queue_max_sectors_show,
257         .store = queue_max_sectors_store,
258 };
259
260 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
261         .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
262         .show = queue_max_hw_sectors_show,
263 };
264
265 static struct queue_sysfs_entry queue_iosched_entry = {
266         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
267         .show = elv_iosched_show,
268         .store = elv_iosched_store,
269 };
270
271 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
272         .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
273         .show = queue_logical_block_size_show,
274 };
275
276 static struct queue_sysfs_entry queue_logical_block_size_entry = {
277         .attr = {.name = "logical_block_size", .mode = S_IRUGO },
278         .show = queue_logical_block_size_show,
279 };
280
281 static struct queue_sysfs_entry queue_physical_block_size_entry = {
282         .attr = {.name = "physical_block_size", .mode = S_IRUGO },
283         .show = queue_physical_block_size_show,
284 };
285
286 static struct queue_sysfs_entry queue_io_min_entry = {
287         .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
288         .show = queue_io_min_show,
289 };
290
291 static struct queue_sysfs_entry queue_io_opt_entry = {
292         .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
293         .show = queue_io_opt_show,
294 };
295
296 static struct queue_sysfs_entry queue_nonrot_entry = {
297         .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
298         .show = queue_nonrot_show,
299         .store = queue_nonrot_store,
300 };
301
302 static struct queue_sysfs_entry queue_nomerges_entry = {
303         .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
304         .show = queue_nomerges_show,
305         .store = queue_nomerges_store,
306 };
307
308 static struct queue_sysfs_entry queue_rq_affinity_entry = {
309         .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
310         .show = queue_rq_affinity_show,
311         .store = queue_rq_affinity_store,
312 };
313
314 static struct queue_sysfs_entry queue_iostats_entry = {
315         .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
316         .show = queue_iostats_show,
317         .store = queue_iostats_store,
318 };
319
320 static struct attribute *default_attrs[] = {
321         &queue_requests_entry.attr,
322         &queue_ra_entry.attr,
323         &queue_max_hw_sectors_entry.attr,
324         &queue_max_sectors_entry.attr,
325         &queue_iosched_entry.attr,
326         &queue_hw_sector_size_entry.attr,
327         &queue_logical_block_size_entry.attr,
328         &queue_physical_block_size_entry.attr,
329         &queue_io_min_entry.attr,
330         &queue_io_opt_entry.attr,
331         &queue_nonrot_entry.attr,
332         &queue_nomerges_entry.attr,
333         &queue_rq_affinity_entry.attr,
334         &queue_iostats_entry.attr,
335         NULL,
336 };
337
338 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
339
340 static ssize_t
341 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
342 {
343         struct queue_sysfs_entry *entry = to_queue(attr);
344         struct request_queue *q =
345                 container_of(kobj, struct request_queue, kobj);
346         ssize_t res;
347
348         if (!entry->show)
349                 return -EIO;
350         mutex_lock(&q->sysfs_lock);
351         if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
352                 mutex_unlock(&q->sysfs_lock);
353                 return -ENOENT;
354         }
355         res = entry->show(q, page);
356         mutex_unlock(&q->sysfs_lock);
357         return res;
358 }
359
360 static ssize_t
361 queue_attr_store(struct kobject *kobj, struct attribute *attr,
362                     const char *page, size_t length)
363 {
364         struct queue_sysfs_entry *entry = to_queue(attr);
365         struct request_queue *q;
366         ssize_t res;
367
368         if (!entry->store)
369                 return -EIO;
370
371         q = container_of(kobj, struct request_queue, kobj);
372         mutex_lock(&q->sysfs_lock);
373         if (test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)) {
374                 mutex_unlock(&q->sysfs_lock);
375                 return -ENOENT;
376         }
377         res = entry->store(q, page, length);
378         mutex_unlock(&q->sysfs_lock);
379         return res;
380 }
381
382 /**
383  * blk_cleanup_queue: - release a &struct request_queue when it is no longer needed
384  * @kobj:    the kobj belonging of the request queue to be released
385  *
386  * Description:
387  *     blk_cleanup_queue is the pair to blk_init_queue() or
388  *     blk_queue_make_request().  It should be called when a request queue is
389  *     being released; typically when a block device is being de-registered.
390  *     Currently, its primary task it to free all the &struct request
391  *     structures that were allocated to the queue and the queue itself.
392  *
393  * Caveat:
394  *     Hopefully the low level driver will have finished any
395  *     outstanding requests first...
396  **/
397 static void blk_release_queue(struct kobject *kobj)
398 {
399         struct request_queue *q =
400                 container_of(kobj, struct request_queue, kobj);
401         struct request_list *rl = &q->rq;
402
403         blk_sync_queue(q);
404
405         if (rl->rq_pool)
406                 mempool_destroy(rl->rq_pool);
407
408         if (q->queue_tags)
409                 __blk_queue_free_tags(q);
410
411         blk_trace_shutdown(q);
412
413         bdi_destroy(&q->backing_dev_info);
414         kmem_cache_free(blk_requestq_cachep, q);
415 }
416
417 static struct sysfs_ops queue_sysfs_ops = {
418         .show   = queue_attr_show,
419         .store  = queue_attr_store,
420 };
421
422 struct kobj_type blk_queue_ktype = {
423         .sysfs_ops      = &queue_sysfs_ops,
424         .default_attrs  = default_attrs,
425         .release        = blk_release_queue,
426 };
427
428 int blk_register_queue(struct gendisk *disk)
429 {
430         int ret;
431         struct device *dev = disk_to_dev(disk);
432
433         struct request_queue *q = disk->queue;
434
435         if (WARN_ON(!q))
436                 return -ENXIO;
437
438         ret = blk_trace_init_sysfs(dev);
439         if (ret)
440                 return ret;
441
442         ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
443         if (ret < 0)
444                 return ret;
445
446         kobject_uevent(&q->kobj, KOBJ_ADD);
447
448         if (!q->request_fn)
449                 return 0;
450
451         ret = elv_register_queue(q);
452         if (ret) {
453                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
454                 kobject_del(&q->kobj);
455                 blk_trace_remove_sysfs(disk_to_dev(disk));
456                 return ret;
457         }
458
459         return 0;
460 }
461
462 void blk_unregister_queue(struct gendisk *disk)
463 {
464         struct request_queue *q = disk->queue;
465
466         if (WARN_ON(!q))
467                 return;
468
469         if (q->request_fn)
470                 elv_unregister_queue(q);
471
472         kobject_uevent(&q->kobj, KOBJ_REMOVE);
473         kobject_del(&q->kobj);
474         blk_trace_remove_sysfs(disk_to_dev(disk));
475         kobject_put(&disk_to_dev(disk)->kobj);
476 }