Merge git://git.infradead.org/users/eparis/audit
[platform/adaptation/renesas_rcar/renesas_kernel.git] / block / blk-sysfs.c
1 /*
2  * Functions related to sysfs handling
3  */
4 #include <linux/kernel.h>
5 #include <linux/slab.h>
6 #include <linux/module.h>
7 #include <linux/bio.h>
8 #include <linux/blkdev.h>
9 #include <linux/blktrace_api.h>
10 #include <linux/blk-mq.h>
11
12 #include "blk.h"
13 #include "blk-cgroup.h"
14
15 struct queue_sysfs_entry {
16         struct attribute attr;
17         ssize_t (*show)(struct request_queue *, char *);
18         ssize_t (*store)(struct request_queue *, const char *, size_t);
19 };
20
21 static ssize_t
22 queue_var_show(unsigned long var, char *page)
23 {
24         return sprintf(page, "%lu\n", var);
25 }
26
27 static ssize_t
28 queue_var_store(unsigned long *var, const char *page, size_t count)
29 {
30         int err;
31         unsigned long v;
32
33         err = kstrtoul(page, 10, &v);
34         if (err || v > UINT_MAX)
35                 return -EINVAL;
36
37         *var = v;
38
39         return count;
40 }
41
42 static ssize_t queue_requests_show(struct request_queue *q, char *page)
43 {
44         return queue_var_show(q->nr_requests, (page));
45 }
46
47 static ssize_t
48 queue_requests_store(struct request_queue *q, const char *page, size_t count)
49 {
50         struct request_list *rl;
51         unsigned long nr;
52         int ret;
53
54         if (!q->request_fn)
55                 return -EINVAL;
56
57         ret = queue_var_store(&nr, page, count);
58         if (ret < 0)
59                 return ret;
60
61         if (nr < BLKDEV_MIN_RQ)
62                 nr = BLKDEV_MIN_RQ;
63
64         spin_lock_irq(q->queue_lock);
65         q->nr_requests = nr;
66         blk_queue_congestion_threshold(q);
67
68         /* congestion isn't cgroup aware and follows root blkcg for now */
69         rl = &q->root_rl;
70
71         if (rl->count[BLK_RW_SYNC] >= queue_congestion_on_threshold(q))
72                 blk_set_queue_congested(q, BLK_RW_SYNC);
73         else if (rl->count[BLK_RW_SYNC] < queue_congestion_off_threshold(q))
74                 blk_clear_queue_congested(q, BLK_RW_SYNC);
75
76         if (rl->count[BLK_RW_ASYNC] >= queue_congestion_on_threshold(q))
77                 blk_set_queue_congested(q, BLK_RW_ASYNC);
78         else if (rl->count[BLK_RW_ASYNC] < queue_congestion_off_threshold(q))
79                 blk_clear_queue_congested(q, BLK_RW_ASYNC);
80
81         blk_queue_for_each_rl(rl, q) {
82                 if (rl->count[BLK_RW_SYNC] >= q->nr_requests) {
83                         blk_set_rl_full(rl, BLK_RW_SYNC);
84                 } else {
85                         blk_clear_rl_full(rl, BLK_RW_SYNC);
86                         wake_up(&rl->wait[BLK_RW_SYNC]);
87                 }
88
89                 if (rl->count[BLK_RW_ASYNC] >= q->nr_requests) {
90                         blk_set_rl_full(rl, BLK_RW_ASYNC);
91                 } else {
92                         blk_clear_rl_full(rl, BLK_RW_ASYNC);
93                         wake_up(&rl->wait[BLK_RW_ASYNC]);
94                 }
95         }
96
97         spin_unlock_irq(q->queue_lock);
98         return ret;
99 }
100
101 static ssize_t queue_ra_show(struct request_queue *q, char *page)
102 {
103         unsigned long ra_kb = q->backing_dev_info.ra_pages <<
104                                         (PAGE_CACHE_SHIFT - 10);
105
106         return queue_var_show(ra_kb, (page));
107 }
108
109 static ssize_t
110 queue_ra_store(struct request_queue *q, const char *page, size_t count)
111 {
112         unsigned long ra_kb;
113         ssize_t ret = queue_var_store(&ra_kb, page, count);
114
115         if (ret < 0)
116                 return ret;
117
118         q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
119
120         return ret;
121 }
122
123 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
124 {
125         int max_sectors_kb = queue_max_sectors(q) >> 1;
126
127         return queue_var_show(max_sectors_kb, (page));
128 }
129
130 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
131 {
132         return queue_var_show(queue_max_segments(q), (page));
133 }
134
135 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
136 {
137         return queue_var_show(q->limits.max_integrity_segments, (page));
138 }
139
140 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
141 {
142         if (blk_queue_cluster(q))
143                 return queue_var_show(queue_max_segment_size(q), (page));
144
145         return queue_var_show(PAGE_CACHE_SIZE, (page));
146 }
147
148 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
149 {
150         return queue_var_show(queue_logical_block_size(q), page);
151 }
152
153 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
154 {
155         return queue_var_show(queue_physical_block_size(q), page);
156 }
157
158 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
159 {
160         return queue_var_show(queue_io_min(q), page);
161 }
162
163 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
164 {
165         return queue_var_show(queue_io_opt(q), page);
166 }
167
168 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
169 {
170         return queue_var_show(q->limits.discard_granularity, page);
171 }
172
173 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
174 {
175         return sprintf(page, "%llu\n",
176                        (unsigned long long)q->limits.max_discard_sectors << 9);
177 }
178
179 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
180 {
181         return queue_var_show(queue_discard_zeroes_data(q), page);
182 }
183
184 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
185 {
186         return sprintf(page, "%llu\n",
187                 (unsigned long long)q->limits.max_write_same_sectors << 9);
188 }
189
190
191 static ssize_t
192 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
193 {
194         unsigned long max_sectors_kb,
195                 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
196                         page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
197         ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
198
199         if (ret < 0)
200                 return ret;
201
202         if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
203                 return -EINVAL;
204
205         spin_lock_irq(q->queue_lock);
206         q->limits.max_sectors = max_sectors_kb << 1;
207         spin_unlock_irq(q->queue_lock);
208
209         return ret;
210 }
211
212 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
213 {
214         int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
215
216         return queue_var_show(max_hw_sectors_kb, (page));
217 }
218
219 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg)                            \
220 static ssize_t                                                          \
221 queue_show_##name(struct request_queue *q, char *page)                  \
222 {                                                                       \
223         int bit;                                                        \
224         bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags);             \
225         return queue_var_show(neg ? !bit : bit, page);                  \
226 }                                                                       \
227 static ssize_t                                                          \
228 queue_store_##name(struct request_queue *q, const char *page, size_t count) \
229 {                                                                       \
230         unsigned long val;                                              \
231         ssize_t ret;                                                    \
232         ret = queue_var_store(&val, page, count);                       \
233         if (ret < 0)                                                    \
234                  return ret;                                            \
235         if (neg)                                                        \
236                 val = !val;                                             \
237                                                                         \
238         spin_lock_irq(q->queue_lock);                                   \
239         if (val)                                                        \
240                 queue_flag_set(QUEUE_FLAG_##flag, q);                   \
241         else                                                            \
242                 queue_flag_clear(QUEUE_FLAG_##flag, q);                 \
243         spin_unlock_irq(q->queue_lock);                                 \
244         return ret;                                                     \
245 }
246
247 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
248 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
249 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
250 #undef QUEUE_SYSFS_BIT_FNS
251
252 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
253 {
254         return queue_var_show((blk_queue_nomerges(q) << 1) |
255                                blk_queue_noxmerges(q), page);
256 }
257
258 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
259                                     size_t count)
260 {
261         unsigned long nm;
262         ssize_t ret = queue_var_store(&nm, page, count);
263
264         if (ret < 0)
265                 return ret;
266
267         spin_lock_irq(q->queue_lock);
268         queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
269         queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
270         if (nm == 2)
271                 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
272         else if (nm)
273                 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
274         spin_unlock_irq(q->queue_lock);
275
276         return ret;
277 }
278
279 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
280 {
281         bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
282         bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
283
284         return queue_var_show(set << force, page);
285 }
286
287 static ssize_t
288 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
289 {
290         ssize_t ret = -EINVAL;
291 #ifdef CONFIG_SMP
292         unsigned long val;
293
294         ret = queue_var_store(&val, page, count);
295         if (ret < 0)
296                 return ret;
297
298         spin_lock_irq(q->queue_lock);
299         if (val == 2) {
300                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
301                 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
302         } else if (val == 1) {
303                 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
304                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
305         } else if (val == 0) {
306                 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
307                 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
308         }
309         spin_unlock_irq(q->queue_lock);
310 #endif
311         return ret;
312 }
313
314 static struct queue_sysfs_entry queue_requests_entry = {
315         .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
316         .show = queue_requests_show,
317         .store = queue_requests_store,
318 };
319
320 static struct queue_sysfs_entry queue_ra_entry = {
321         .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
322         .show = queue_ra_show,
323         .store = queue_ra_store,
324 };
325
326 static struct queue_sysfs_entry queue_max_sectors_entry = {
327         .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
328         .show = queue_max_sectors_show,
329         .store = queue_max_sectors_store,
330 };
331
332 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
333         .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
334         .show = queue_max_hw_sectors_show,
335 };
336
337 static struct queue_sysfs_entry queue_max_segments_entry = {
338         .attr = {.name = "max_segments", .mode = S_IRUGO },
339         .show = queue_max_segments_show,
340 };
341
342 static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
343         .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
344         .show = queue_max_integrity_segments_show,
345 };
346
347 static struct queue_sysfs_entry queue_max_segment_size_entry = {
348         .attr = {.name = "max_segment_size", .mode = S_IRUGO },
349         .show = queue_max_segment_size_show,
350 };
351
352 static struct queue_sysfs_entry queue_iosched_entry = {
353         .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
354         .show = elv_iosched_show,
355         .store = elv_iosched_store,
356 };
357
358 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
359         .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
360         .show = queue_logical_block_size_show,
361 };
362
363 static struct queue_sysfs_entry queue_logical_block_size_entry = {
364         .attr = {.name = "logical_block_size", .mode = S_IRUGO },
365         .show = queue_logical_block_size_show,
366 };
367
368 static struct queue_sysfs_entry queue_physical_block_size_entry = {
369         .attr = {.name = "physical_block_size", .mode = S_IRUGO },
370         .show = queue_physical_block_size_show,
371 };
372
373 static struct queue_sysfs_entry queue_io_min_entry = {
374         .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
375         .show = queue_io_min_show,
376 };
377
378 static struct queue_sysfs_entry queue_io_opt_entry = {
379         .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
380         .show = queue_io_opt_show,
381 };
382
383 static struct queue_sysfs_entry queue_discard_granularity_entry = {
384         .attr = {.name = "discard_granularity", .mode = S_IRUGO },
385         .show = queue_discard_granularity_show,
386 };
387
388 static struct queue_sysfs_entry queue_discard_max_entry = {
389         .attr = {.name = "discard_max_bytes", .mode = S_IRUGO },
390         .show = queue_discard_max_show,
391 };
392
393 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
394         .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
395         .show = queue_discard_zeroes_data_show,
396 };
397
398 static struct queue_sysfs_entry queue_write_same_max_entry = {
399         .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
400         .show = queue_write_same_max_show,
401 };
402
403 static struct queue_sysfs_entry queue_nonrot_entry = {
404         .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
405         .show = queue_show_nonrot,
406         .store = queue_store_nonrot,
407 };
408
409 static struct queue_sysfs_entry queue_nomerges_entry = {
410         .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
411         .show = queue_nomerges_show,
412         .store = queue_nomerges_store,
413 };
414
415 static struct queue_sysfs_entry queue_rq_affinity_entry = {
416         .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
417         .show = queue_rq_affinity_show,
418         .store = queue_rq_affinity_store,
419 };
420
421 static struct queue_sysfs_entry queue_iostats_entry = {
422         .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
423         .show = queue_show_iostats,
424         .store = queue_store_iostats,
425 };
426
427 static struct queue_sysfs_entry queue_random_entry = {
428         .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
429         .show = queue_show_random,
430         .store = queue_store_random,
431 };
432
433 static struct attribute *default_attrs[] = {
434         &queue_requests_entry.attr,
435         &queue_ra_entry.attr,
436         &queue_max_hw_sectors_entry.attr,
437         &queue_max_sectors_entry.attr,
438         &queue_max_segments_entry.attr,
439         &queue_max_integrity_segments_entry.attr,
440         &queue_max_segment_size_entry.attr,
441         &queue_iosched_entry.attr,
442         &queue_hw_sector_size_entry.attr,
443         &queue_logical_block_size_entry.attr,
444         &queue_physical_block_size_entry.attr,
445         &queue_io_min_entry.attr,
446         &queue_io_opt_entry.attr,
447         &queue_discard_granularity_entry.attr,
448         &queue_discard_max_entry.attr,
449         &queue_discard_zeroes_data_entry.attr,
450         &queue_write_same_max_entry.attr,
451         &queue_nonrot_entry.attr,
452         &queue_nomerges_entry.attr,
453         &queue_rq_affinity_entry.attr,
454         &queue_iostats_entry.attr,
455         &queue_random_entry.attr,
456         NULL,
457 };
458
459 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
460
461 static ssize_t
462 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
463 {
464         struct queue_sysfs_entry *entry = to_queue(attr);
465         struct request_queue *q =
466                 container_of(kobj, struct request_queue, kobj);
467         ssize_t res;
468
469         if (!entry->show)
470                 return -EIO;
471         mutex_lock(&q->sysfs_lock);
472         if (blk_queue_dying(q)) {
473                 mutex_unlock(&q->sysfs_lock);
474                 return -ENOENT;
475         }
476         res = entry->show(q, page);
477         mutex_unlock(&q->sysfs_lock);
478         return res;
479 }
480
481 static ssize_t
482 queue_attr_store(struct kobject *kobj, struct attribute *attr,
483                     const char *page, size_t length)
484 {
485         struct queue_sysfs_entry *entry = to_queue(attr);
486         struct request_queue *q;
487         ssize_t res;
488
489         if (!entry->store)
490                 return -EIO;
491
492         q = container_of(kobj, struct request_queue, kobj);
493         mutex_lock(&q->sysfs_lock);
494         if (blk_queue_dying(q)) {
495                 mutex_unlock(&q->sysfs_lock);
496                 return -ENOENT;
497         }
498         res = entry->store(q, page, length);
499         mutex_unlock(&q->sysfs_lock);
500         return res;
501 }
502
503 static void blk_free_queue_rcu(struct rcu_head *rcu_head)
504 {
505         struct request_queue *q = container_of(rcu_head, struct request_queue,
506                                                rcu_head);
507         kmem_cache_free(blk_requestq_cachep, q);
508 }
509
510 /**
511  * blk_release_queue: - release a &struct request_queue when it is no longer needed
512  * @kobj:    the kobj belonging to the request queue to be released
513  *
514  * Description:
515  *     blk_release_queue is the pair to blk_init_queue() or
516  *     blk_queue_make_request().  It should be called when a request queue is
517  *     being released; typically when a block device is being de-registered.
518  *     Currently, its primary task it to free all the &struct request
519  *     structures that were allocated to the queue and the queue itself.
520  *
521  * Caveat:
522  *     Hopefully the low level driver will have finished any
523  *     outstanding requests first...
524  **/
525 static void blk_release_queue(struct kobject *kobj)
526 {
527         struct request_queue *q =
528                 container_of(kobj, struct request_queue, kobj);
529
530         blk_sync_queue(q);
531
532         blkcg_exit_queue(q);
533
534         if (q->elevator) {
535                 spin_lock_irq(q->queue_lock);
536                 ioc_clear_queue(q);
537                 spin_unlock_irq(q->queue_lock);
538                 elevator_exit(q->elevator);
539         }
540
541         blk_exit_rl(&q->root_rl);
542
543         if (q->queue_tags)
544                 __blk_queue_free_tags(q);
545
546         percpu_counter_destroy(&q->mq_usage_counter);
547
548         if (q->mq_ops)
549                 blk_mq_free_queue(q);
550
551         blk_trace_shutdown(q);
552
553         bdi_destroy(&q->backing_dev_info);
554
555         ida_simple_remove(&blk_queue_ida, q->id);
556         call_rcu(&q->rcu_head, blk_free_queue_rcu);
557 }
558
559 static const struct sysfs_ops queue_sysfs_ops = {
560         .show   = queue_attr_show,
561         .store  = queue_attr_store,
562 };
563
564 struct kobj_type blk_queue_ktype = {
565         .sysfs_ops      = &queue_sysfs_ops,
566         .default_attrs  = default_attrs,
567         .release        = blk_release_queue,
568 };
569
570 int blk_register_queue(struct gendisk *disk)
571 {
572         int ret;
573         struct device *dev = disk_to_dev(disk);
574         struct request_queue *q = disk->queue;
575
576         if (WARN_ON(!q))
577                 return -ENXIO;
578
579         /*
580          * Initialization must be complete by now.  Finish the initial
581          * bypass from queue allocation.
582          */
583         blk_queue_bypass_end(q);
584         queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
585
586         ret = blk_trace_init_sysfs(dev);
587         if (ret)
588                 return ret;
589
590         ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
591         if (ret < 0) {
592                 blk_trace_remove_sysfs(dev);
593                 return ret;
594         }
595
596         kobject_uevent(&q->kobj, KOBJ_ADD);
597
598         if (q->mq_ops)
599                 blk_mq_register_disk(disk);
600
601         if (!q->request_fn)
602                 return 0;
603
604         ret = elv_register_queue(q);
605         if (ret) {
606                 kobject_uevent(&q->kobj, KOBJ_REMOVE);
607                 kobject_del(&q->kobj);
608                 blk_trace_remove_sysfs(dev);
609                 kobject_put(&dev->kobj);
610                 return ret;
611         }
612
613         return 0;
614 }
615
616 void blk_unregister_queue(struct gendisk *disk)
617 {
618         struct request_queue *q = disk->queue;
619
620         if (WARN_ON(!q))
621                 return;
622
623         if (q->mq_ops)
624                 blk_mq_unregister_disk(disk);
625
626         if (q->request_fn)
627                 elv_unregister_queue(q);
628
629         kobject_uevent(&q->kobj, KOBJ_REMOVE);
630         kobject_del(&q->kobj);
631         blk_trace_remove_sysfs(disk_to_dev(disk));
632         kobject_put(&disk_to_dev(disk)->kobj);
633 }