2 * Functions related to sysfs handling
4 #include <linux/kernel.h>
5 #include <linux/slab.h>
6 #include <linux/module.h>
8 #include <linux/blkdev.h>
9 #include <linux/backing-dev.h>
10 #include <linux/blktrace_api.h>
11 #include <linux/blk-mq.h>
12 #include <linux/blk-cgroup.h>
17 struct queue_sysfs_entry {
18 struct attribute attr;
19 ssize_t (*show)(struct request_queue *, char *);
20 ssize_t (*store)(struct request_queue *, const char *, size_t);
24 queue_var_show(unsigned long var, char *page)
26 return sprintf(page, "%lu\n", var);
30 queue_var_store(unsigned long *var, const char *page, size_t count)
35 err = kstrtoul(page, 10, &v);
36 if (err || v > UINT_MAX)
44 static ssize_t queue_requests_show(struct request_queue *q, char *page)
46 return queue_var_show(q->nr_requests, (page));
50 queue_requests_store(struct request_queue *q, const char *page, size_t count)
55 if (!q->request_fn && !q->mq_ops)
58 ret = queue_var_store(&nr, page, count);
62 if (nr < BLKDEV_MIN_RQ)
66 err = blk_update_nr_requests(q, nr);
68 err = blk_mq_update_nr_requests(q, nr);
76 static ssize_t queue_ra_show(struct request_queue *q, char *page)
78 unsigned long ra_kb = q->backing_dev_info.ra_pages <<
79 (PAGE_CACHE_SHIFT - 10);
81 return queue_var_show(ra_kb, (page));
85 queue_ra_store(struct request_queue *q, const char *page, size_t count)
88 ssize_t ret = queue_var_store(&ra_kb, page, count);
93 q->backing_dev_info.ra_pages = ra_kb >> (PAGE_CACHE_SHIFT - 10);
98 static ssize_t queue_max_sectors_show(struct request_queue *q, char *page)
100 int max_sectors_kb = queue_max_sectors(q) >> 1;
102 return queue_var_show(max_sectors_kb, (page));
105 static ssize_t queue_max_segments_show(struct request_queue *q, char *page)
107 return queue_var_show(queue_max_segments(q), (page));
110 static ssize_t queue_max_integrity_segments_show(struct request_queue *q, char *page)
112 return queue_var_show(q->limits.max_integrity_segments, (page));
115 static ssize_t queue_max_segment_size_show(struct request_queue *q, char *page)
117 if (blk_queue_cluster(q))
118 return queue_var_show(queue_max_segment_size(q), (page));
120 return queue_var_show(PAGE_CACHE_SIZE, (page));
123 static ssize_t queue_logical_block_size_show(struct request_queue *q, char *page)
125 return queue_var_show(queue_logical_block_size(q), page);
128 static ssize_t queue_physical_block_size_show(struct request_queue *q, char *page)
130 return queue_var_show(queue_physical_block_size(q), page);
133 static ssize_t queue_io_min_show(struct request_queue *q, char *page)
135 return queue_var_show(queue_io_min(q), page);
138 static ssize_t queue_io_opt_show(struct request_queue *q, char *page)
140 return queue_var_show(queue_io_opt(q), page);
143 static ssize_t queue_discard_granularity_show(struct request_queue *q, char *page)
145 return queue_var_show(q->limits.discard_granularity, page);
148 static ssize_t queue_discard_max_hw_show(struct request_queue *q, char *page)
150 unsigned long long val;
152 val = q->limits.max_hw_discard_sectors << 9;
153 return sprintf(page, "%llu\n", val);
156 static ssize_t queue_discard_max_show(struct request_queue *q, char *page)
158 return sprintf(page, "%llu\n",
159 (unsigned long long)q->limits.max_discard_sectors << 9);
162 static ssize_t queue_discard_max_store(struct request_queue *q,
163 const char *page, size_t count)
165 unsigned long max_discard;
166 ssize_t ret = queue_var_store(&max_discard, page, count);
171 if (max_discard & (q->limits.discard_granularity - 1))
175 if (max_discard > UINT_MAX)
178 if (max_discard > q->limits.max_hw_discard_sectors)
179 max_discard = q->limits.max_hw_discard_sectors;
181 q->limits.max_discard_sectors = max_discard;
185 static ssize_t queue_discard_zeroes_data_show(struct request_queue *q, char *page)
187 return queue_var_show(queue_discard_zeroes_data(q), page);
190 static ssize_t queue_write_same_max_show(struct request_queue *q, char *page)
192 return sprintf(page, "%llu\n",
193 (unsigned long long)q->limits.max_write_same_sectors << 9);
198 queue_max_sectors_store(struct request_queue *q, const char *page, size_t count)
200 unsigned long max_sectors_kb,
201 max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1,
202 page_kb = 1 << (PAGE_CACHE_SHIFT - 10);
203 ssize_t ret = queue_var_store(&max_sectors_kb, page, count);
208 if (max_sectors_kb > max_hw_sectors_kb || max_sectors_kb < page_kb)
211 spin_lock_irq(q->queue_lock);
212 q->limits.max_sectors = max_sectors_kb << 1;
213 spin_unlock_irq(q->queue_lock);
218 static ssize_t queue_max_hw_sectors_show(struct request_queue *q, char *page)
220 int max_hw_sectors_kb = queue_max_hw_sectors(q) >> 1;
222 return queue_var_show(max_hw_sectors_kb, (page));
225 #define QUEUE_SYSFS_BIT_FNS(name, flag, neg) \
227 queue_show_##name(struct request_queue *q, char *page) \
230 bit = test_bit(QUEUE_FLAG_##flag, &q->queue_flags); \
231 return queue_var_show(neg ? !bit : bit, page); \
234 queue_store_##name(struct request_queue *q, const char *page, size_t count) \
238 ret = queue_var_store(&val, page, count); \
244 spin_lock_irq(q->queue_lock); \
246 queue_flag_set(QUEUE_FLAG_##flag, q); \
248 queue_flag_clear(QUEUE_FLAG_##flag, q); \
249 spin_unlock_irq(q->queue_lock); \
253 QUEUE_SYSFS_BIT_FNS(nonrot, NONROT, 1);
254 QUEUE_SYSFS_BIT_FNS(random, ADD_RANDOM, 0);
255 QUEUE_SYSFS_BIT_FNS(iostats, IO_STAT, 0);
256 #undef QUEUE_SYSFS_BIT_FNS
258 static ssize_t queue_nomerges_show(struct request_queue *q, char *page)
260 return queue_var_show((blk_queue_nomerges(q) << 1) |
261 blk_queue_noxmerges(q), page);
264 static ssize_t queue_nomerges_store(struct request_queue *q, const char *page,
268 ssize_t ret = queue_var_store(&nm, page, count);
273 spin_lock_irq(q->queue_lock);
274 queue_flag_clear(QUEUE_FLAG_NOMERGES, q);
275 queue_flag_clear(QUEUE_FLAG_NOXMERGES, q);
277 queue_flag_set(QUEUE_FLAG_NOMERGES, q);
279 queue_flag_set(QUEUE_FLAG_NOXMERGES, q);
280 spin_unlock_irq(q->queue_lock);
285 static ssize_t queue_rq_affinity_show(struct request_queue *q, char *page)
287 bool set = test_bit(QUEUE_FLAG_SAME_COMP, &q->queue_flags);
288 bool force = test_bit(QUEUE_FLAG_SAME_FORCE, &q->queue_flags);
290 return queue_var_show(set << force, page);
294 queue_rq_affinity_store(struct request_queue *q, const char *page, size_t count)
296 ssize_t ret = -EINVAL;
300 ret = queue_var_store(&val, page, count);
304 spin_lock_irq(q->queue_lock);
306 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
307 queue_flag_set(QUEUE_FLAG_SAME_FORCE, q);
308 } else if (val == 1) {
309 queue_flag_set(QUEUE_FLAG_SAME_COMP, q);
310 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
311 } else if (val == 0) {
312 queue_flag_clear(QUEUE_FLAG_SAME_COMP, q);
313 queue_flag_clear(QUEUE_FLAG_SAME_FORCE, q);
315 spin_unlock_irq(q->queue_lock);
320 static struct queue_sysfs_entry queue_requests_entry = {
321 .attr = {.name = "nr_requests", .mode = S_IRUGO | S_IWUSR },
322 .show = queue_requests_show,
323 .store = queue_requests_store,
326 static struct queue_sysfs_entry queue_ra_entry = {
327 .attr = {.name = "read_ahead_kb", .mode = S_IRUGO | S_IWUSR },
328 .show = queue_ra_show,
329 .store = queue_ra_store,
332 static struct queue_sysfs_entry queue_max_sectors_entry = {
333 .attr = {.name = "max_sectors_kb", .mode = S_IRUGO | S_IWUSR },
334 .show = queue_max_sectors_show,
335 .store = queue_max_sectors_store,
338 static struct queue_sysfs_entry queue_max_hw_sectors_entry = {
339 .attr = {.name = "max_hw_sectors_kb", .mode = S_IRUGO },
340 .show = queue_max_hw_sectors_show,
343 static struct queue_sysfs_entry queue_max_segments_entry = {
344 .attr = {.name = "max_segments", .mode = S_IRUGO },
345 .show = queue_max_segments_show,
348 static struct queue_sysfs_entry queue_max_integrity_segments_entry = {
349 .attr = {.name = "max_integrity_segments", .mode = S_IRUGO },
350 .show = queue_max_integrity_segments_show,
353 static struct queue_sysfs_entry queue_max_segment_size_entry = {
354 .attr = {.name = "max_segment_size", .mode = S_IRUGO },
355 .show = queue_max_segment_size_show,
358 static struct queue_sysfs_entry queue_iosched_entry = {
359 .attr = {.name = "scheduler", .mode = S_IRUGO | S_IWUSR },
360 .show = elv_iosched_show,
361 .store = elv_iosched_store,
364 static struct queue_sysfs_entry queue_hw_sector_size_entry = {
365 .attr = {.name = "hw_sector_size", .mode = S_IRUGO },
366 .show = queue_logical_block_size_show,
369 static struct queue_sysfs_entry queue_logical_block_size_entry = {
370 .attr = {.name = "logical_block_size", .mode = S_IRUGO },
371 .show = queue_logical_block_size_show,
374 static struct queue_sysfs_entry queue_physical_block_size_entry = {
375 .attr = {.name = "physical_block_size", .mode = S_IRUGO },
376 .show = queue_physical_block_size_show,
379 static struct queue_sysfs_entry queue_io_min_entry = {
380 .attr = {.name = "minimum_io_size", .mode = S_IRUGO },
381 .show = queue_io_min_show,
384 static struct queue_sysfs_entry queue_io_opt_entry = {
385 .attr = {.name = "optimal_io_size", .mode = S_IRUGO },
386 .show = queue_io_opt_show,
389 static struct queue_sysfs_entry queue_discard_granularity_entry = {
390 .attr = {.name = "discard_granularity", .mode = S_IRUGO },
391 .show = queue_discard_granularity_show,
394 static struct queue_sysfs_entry queue_discard_max_hw_entry = {
395 .attr = {.name = "discard_max_hw_bytes", .mode = S_IRUGO },
396 .show = queue_discard_max_hw_show,
399 static struct queue_sysfs_entry queue_discard_max_entry = {
400 .attr = {.name = "discard_max_bytes", .mode = S_IRUGO | S_IWUSR },
401 .show = queue_discard_max_show,
402 .store = queue_discard_max_store,
405 static struct queue_sysfs_entry queue_discard_zeroes_data_entry = {
406 .attr = {.name = "discard_zeroes_data", .mode = S_IRUGO },
407 .show = queue_discard_zeroes_data_show,
410 static struct queue_sysfs_entry queue_write_same_max_entry = {
411 .attr = {.name = "write_same_max_bytes", .mode = S_IRUGO },
412 .show = queue_write_same_max_show,
415 static struct queue_sysfs_entry queue_nonrot_entry = {
416 .attr = {.name = "rotational", .mode = S_IRUGO | S_IWUSR },
417 .show = queue_show_nonrot,
418 .store = queue_store_nonrot,
421 static struct queue_sysfs_entry queue_nomerges_entry = {
422 .attr = {.name = "nomerges", .mode = S_IRUGO | S_IWUSR },
423 .show = queue_nomerges_show,
424 .store = queue_nomerges_store,
427 static struct queue_sysfs_entry queue_rq_affinity_entry = {
428 .attr = {.name = "rq_affinity", .mode = S_IRUGO | S_IWUSR },
429 .show = queue_rq_affinity_show,
430 .store = queue_rq_affinity_store,
433 static struct queue_sysfs_entry queue_iostats_entry = {
434 .attr = {.name = "iostats", .mode = S_IRUGO | S_IWUSR },
435 .show = queue_show_iostats,
436 .store = queue_store_iostats,
439 static struct queue_sysfs_entry queue_random_entry = {
440 .attr = {.name = "add_random", .mode = S_IRUGO | S_IWUSR },
441 .show = queue_show_random,
442 .store = queue_store_random,
445 static struct attribute *default_attrs[] = {
446 &queue_requests_entry.attr,
447 &queue_ra_entry.attr,
448 &queue_max_hw_sectors_entry.attr,
449 &queue_max_sectors_entry.attr,
450 &queue_max_segments_entry.attr,
451 &queue_max_integrity_segments_entry.attr,
452 &queue_max_segment_size_entry.attr,
453 &queue_iosched_entry.attr,
454 &queue_hw_sector_size_entry.attr,
455 &queue_logical_block_size_entry.attr,
456 &queue_physical_block_size_entry.attr,
457 &queue_io_min_entry.attr,
458 &queue_io_opt_entry.attr,
459 &queue_discard_granularity_entry.attr,
460 &queue_discard_max_entry.attr,
461 &queue_discard_max_hw_entry.attr,
462 &queue_discard_zeroes_data_entry.attr,
463 &queue_write_same_max_entry.attr,
464 &queue_nonrot_entry.attr,
465 &queue_nomerges_entry.attr,
466 &queue_rq_affinity_entry.attr,
467 &queue_iostats_entry.attr,
468 &queue_random_entry.attr,
472 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
475 queue_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
477 struct queue_sysfs_entry *entry = to_queue(attr);
478 struct request_queue *q =
479 container_of(kobj, struct request_queue, kobj);
484 mutex_lock(&q->sysfs_lock);
485 if (blk_queue_dying(q)) {
486 mutex_unlock(&q->sysfs_lock);
489 res = entry->show(q, page);
490 mutex_unlock(&q->sysfs_lock);
495 queue_attr_store(struct kobject *kobj, struct attribute *attr,
496 const char *page, size_t length)
498 struct queue_sysfs_entry *entry = to_queue(attr);
499 struct request_queue *q;
505 q = container_of(kobj, struct request_queue, kobj);
506 mutex_lock(&q->sysfs_lock);
507 if (blk_queue_dying(q)) {
508 mutex_unlock(&q->sysfs_lock);
511 res = entry->store(q, page, length);
512 mutex_unlock(&q->sysfs_lock);
516 static void blk_free_queue_rcu(struct rcu_head *rcu_head)
518 struct request_queue *q = container_of(rcu_head, struct request_queue,
520 kmem_cache_free(blk_requestq_cachep, q);
524 * blk_release_queue: - release a &struct request_queue when it is no longer needed
525 * @kobj: the kobj belonging to the request queue to be released
528 * blk_release_queue is the pair to blk_init_queue() or
529 * blk_queue_make_request(). It should be called when a request queue is
530 * being released; typically when a block device is being de-registered.
531 * Currently, its primary task it to free all the &struct request
532 * structures that were allocated to the queue and the queue itself.
535 * The low level driver must have finished any outstanding requests first
536 * via blk_cleanup_queue().
538 static void blk_release_queue(struct kobject *kobj)
540 struct request_queue *q =
541 container_of(kobj, struct request_queue, kobj);
543 bdi_exit(&q->backing_dev_info);
547 spin_lock_irq(q->queue_lock);
549 spin_unlock_irq(q->queue_lock);
550 elevator_exit(q->elevator);
553 blk_exit_rl(&q->root_rl);
556 __blk_queue_free_tags(q);
559 blk_free_flush_queue(q->fq);
563 blk_trace_shutdown(q);
566 bioset_free(q->bio_split);
568 ida_simple_remove(&blk_queue_ida, q->id);
569 call_rcu(&q->rcu_head, blk_free_queue_rcu);
572 static const struct sysfs_ops queue_sysfs_ops = {
573 .show = queue_attr_show,
574 .store = queue_attr_store,
577 struct kobj_type blk_queue_ktype = {
578 .sysfs_ops = &queue_sysfs_ops,
579 .default_attrs = default_attrs,
580 .release = blk_release_queue,
583 int blk_register_queue(struct gendisk *disk)
586 struct device *dev = disk_to_dev(disk);
587 struct request_queue *q = disk->queue;
593 * SCSI probing may synchronously create and destroy a lot of
594 * request_queues for non-existent devices. Shutting down a fully
595 * functional queue takes measureable wallclock time as RCU grace
596 * periods are involved. To avoid excessive latency in these
597 * cases, a request_queue starts out in a degraded mode which is
598 * faster to shut down and is made fully functional here as
599 * request_queues for non-existent devices never get registered.
601 if (!blk_queue_init_done(q)) {
602 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q);
603 percpu_ref_switch_to_percpu(&q->q_usage_counter);
604 blk_queue_bypass_end(q);
607 ret = blk_trace_init_sysfs(dev);
611 ret = kobject_add(&q->kobj, kobject_get(&dev->kobj), "%s", "queue");
613 blk_trace_remove_sysfs(dev);
617 kobject_uevent(&q->kobj, KOBJ_ADD);
620 blk_mq_register_disk(disk);
625 ret = elv_register_queue(q);
627 kobject_uevent(&q->kobj, KOBJ_REMOVE);
628 kobject_del(&q->kobj);
629 blk_trace_remove_sysfs(dev);
630 kobject_put(&dev->kobj);
637 void blk_unregister_queue(struct gendisk *disk)
639 struct request_queue *q = disk->queue;
645 blk_mq_unregister_disk(disk);
648 elv_unregister_queue(q);
650 kobject_uevent(&q->kobj, KOBJ_REMOVE);
651 kobject_del(&q->kobj);
652 blk_trace_remove_sysfs(disk_to_dev(disk));
653 kobject_put(&disk_to_dev(disk)->kobj);