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 ssize_t
queue_poll_show(struct request_queue
*q
, char *page
)
322 return queue_var_show(test_bit(QUEUE_FLAG_POLL
, &q
->queue_flags
), page
);
325 static ssize_t
queue_poll_store(struct request_queue
*q
, const char *page
,
328 unsigned long poll_on
;
331 if (!q
->mq_ops
|| !q
->mq_ops
->poll
)
334 ret
= queue_var_store(&poll_on
, page
, count
);
338 spin_lock_irq(q
->queue_lock
);
340 queue_flag_set(QUEUE_FLAG_POLL
, q
);
342 queue_flag_clear(QUEUE_FLAG_POLL
, q
);
343 spin_unlock_irq(q
->queue_lock
);
348 static struct queue_sysfs_entry queue_requests_entry
= {
349 .attr
= {.name
= "nr_requests", .mode
= S_IRUGO
| S_IWUSR
},
350 .show
= queue_requests_show
,
351 .store
= queue_requests_store
,
354 static struct queue_sysfs_entry queue_ra_entry
= {
355 .attr
= {.name
= "read_ahead_kb", .mode
= S_IRUGO
| S_IWUSR
},
356 .show
= queue_ra_show
,
357 .store
= queue_ra_store
,
360 static struct queue_sysfs_entry queue_max_sectors_entry
= {
361 .attr
= {.name
= "max_sectors_kb", .mode
= S_IRUGO
| S_IWUSR
},
362 .show
= queue_max_sectors_show
,
363 .store
= queue_max_sectors_store
,
366 static struct queue_sysfs_entry queue_max_hw_sectors_entry
= {
367 .attr
= {.name
= "max_hw_sectors_kb", .mode
= S_IRUGO
},
368 .show
= queue_max_hw_sectors_show
,
371 static struct queue_sysfs_entry queue_max_segments_entry
= {
372 .attr
= {.name
= "max_segments", .mode
= S_IRUGO
},
373 .show
= queue_max_segments_show
,
376 static struct queue_sysfs_entry queue_max_integrity_segments_entry
= {
377 .attr
= {.name
= "max_integrity_segments", .mode
= S_IRUGO
},
378 .show
= queue_max_integrity_segments_show
,
381 static struct queue_sysfs_entry queue_max_segment_size_entry
= {
382 .attr
= {.name
= "max_segment_size", .mode
= S_IRUGO
},
383 .show
= queue_max_segment_size_show
,
386 static struct queue_sysfs_entry queue_iosched_entry
= {
387 .attr
= {.name
= "scheduler", .mode
= S_IRUGO
| S_IWUSR
},
388 .show
= elv_iosched_show
,
389 .store
= elv_iosched_store
,
392 static struct queue_sysfs_entry queue_hw_sector_size_entry
= {
393 .attr
= {.name
= "hw_sector_size", .mode
= S_IRUGO
},
394 .show
= queue_logical_block_size_show
,
397 static struct queue_sysfs_entry queue_logical_block_size_entry
= {
398 .attr
= {.name
= "logical_block_size", .mode
= S_IRUGO
},
399 .show
= queue_logical_block_size_show
,
402 static struct queue_sysfs_entry queue_physical_block_size_entry
= {
403 .attr
= {.name
= "physical_block_size", .mode
= S_IRUGO
},
404 .show
= queue_physical_block_size_show
,
407 static struct queue_sysfs_entry queue_io_min_entry
= {
408 .attr
= {.name
= "minimum_io_size", .mode
= S_IRUGO
},
409 .show
= queue_io_min_show
,
412 static struct queue_sysfs_entry queue_io_opt_entry
= {
413 .attr
= {.name
= "optimal_io_size", .mode
= S_IRUGO
},
414 .show
= queue_io_opt_show
,
417 static struct queue_sysfs_entry queue_discard_granularity_entry
= {
418 .attr
= {.name
= "discard_granularity", .mode
= S_IRUGO
},
419 .show
= queue_discard_granularity_show
,
422 static struct queue_sysfs_entry queue_discard_max_hw_entry
= {
423 .attr
= {.name
= "discard_max_hw_bytes", .mode
= S_IRUGO
},
424 .show
= queue_discard_max_hw_show
,
427 static struct queue_sysfs_entry queue_discard_max_entry
= {
428 .attr
= {.name
= "discard_max_bytes", .mode
= S_IRUGO
| S_IWUSR
},
429 .show
= queue_discard_max_show
,
430 .store
= queue_discard_max_store
,
433 static struct queue_sysfs_entry queue_discard_zeroes_data_entry
= {
434 .attr
= {.name
= "discard_zeroes_data", .mode
= S_IRUGO
},
435 .show
= queue_discard_zeroes_data_show
,
438 static struct queue_sysfs_entry queue_write_same_max_entry
= {
439 .attr
= {.name
= "write_same_max_bytes", .mode
= S_IRUGO
},
440 .show
= queue_write_same_max_show
,
443 static struct queue_sysfs_entry queue_nonrot_entry
= {
444 .attr
= {.name
= "rotational", .mode
= S_IRUGO
| S_IWUSR
},
445 .show
= queue_show_nonrot
,
446 .store
= queue_store_nonrot
,
449 static struct queue_sysfs_entry queue_nomerges_entry
= {
450 .attr
= {.name
= "nomerges", .mode
= S_IRUGO
| S_IWUSR
},
451 .show
= queue_nomerges_show
,
452 .store
= queue_nomerges_store
,
455 static struct queue_sysfs_entry queue_rq_affinity_entry
= {
456 .attr
= {.name
= "rq_affinity", .mode
= S_IRUGO
| S_IWUSR
},
457 .show
= queue_rq_affinity_show
,
458 .store
= queue_rq_affinity_store
,
461 static struct queue_sysfs_entry queue_iostats_entry
= {
462 .attr
= {.name
= "iostats", .mode
= S_IRUGO
| S_IWUSR
},
463 .show
= queue_show_iostats
,
464 .store
= queue_store_iostats
,
467 static struct queue_sysfs_entry queue_random_entry
= {
468 .attr
= {.name
= "add_random", .mode
= S_IRUGO
| S_IWUSR
},
469 .show
= queue_show_random
,
470 .store
= queue_store_random
,
473 static struct queue_sysfs_entry queue_poll_entry
= {
474 .attr
= {.name
= "io_poll", .mode
= S_IRUGO
| S_IWUSR
},
475 .show
= queue_poll_show
,
476 .store
= queue_poll_store
,
479 static struct attribute
*default_attrs
[] = {
480 &queue_requests_entry
.attr
,
481 &queue_ra_entry
.attr
,
482 &queue_max_hw_sectors_entry
.attr
,
483 &queue_max_sectors_entry
.attr
,
484 &queue_max_segments_entry
.attr
,
485 &queue_max_integrity_segments_entry
.attr
,
486 &queue_max_segment_size_entry
.attr
,
487 &queue_iosched_entry
.attr
,
488 &queue_hw_sector_size_entry
.attr
,
489 &queue_logical_block_size_entry
.attr
,
490 &queue_physical_block_size_entry
.attr
,
491 &queue_io_min_entry
.attr
,
492 &queue_io_opt_entry
.attr
,
493 &queue_discard_granularity_entry
.attr
,
494 &queue_discard_max_entry
.attr
,
495 &queue_discard_max_hw_entry
.attr
,
496 &queue_discard_zeroes_data_entry
.attr
,
497 &queue_write_same_max_entry
.attr
,
498 &queue_nonrot_entry
.attr
,
499 &queue_nomerges_entry
.attr
,
500 &queue_rq_affinity_entry
.attr
,
501 &queue_iostats_entry
.attr
,
502 &queue_random_entry
.attr
,
503 &queue_poll_entry
.attr
,
507 #define to_queue(atr) container_of((atr), struct queue_sysfs_entry, attr)
510 queue_attr_show(struct kobject
*kobj
, struct attribute
*attr
, char *page
)
512 struct queue_sysfs_entry
*entry
= to_queue(attr
);
513 struct request_queue
*q
=
514 container_of(kobj
, struct request_queue
, kobj
);
519 mutex_lock(&q
->sysfs_lock
);
520 if (blk_queue_dying(q
)) {
521 mutex_unlock(&q
->sysfs_lock
);
524 res
= entry
->show(q
, page
);
525 mutex_unlock(&q
->sysfs_lock
);
530 queue_attr_store(struct kobject
*kobj
, struct attribute
*attr
,
531 const char *page
, size_t length
)
533 struct queue_sysfs_entry
*entry
= to_queue(attr
);
534 struct request_queue
*q
;
540 q
= container_of(kobj
, struct request_queue
, kobj
);
541 mutex_lock(&q
->sysfs_lock
);
542 if (blk_queue_dying(q
)) {
543 mutex_unlock(&q
->sysfs_lock
);
546 res
= entry
->store(q
, page
, length
);
547 mutex_unlock(&q
->sysfs_lock
);
551 static void blk_free_queue_rcu(struct rcu_head
*rcu_head
)
553 struct request_queue
*q
= container_of(rcu_head
, struct request_queue
,
555 kmem_cache_free(blk_requestq_cachep
, q
);
559 * blk_release_queue: - release a &struct request_queue when it is no longer needed
560 * @kobj: the kobj belonging to the request queue to be released
563 * blk_release_queue is the pair to blk_init_queue() or
564 * blk_queue_make_request(). It should be called when a request queue is
565 * being released; typically when a block device is being de-registered.
566 * Currently, its primary task it to free all the &struct request
567 * structures that were allocated to the queue and the queue itself.
570 * The low level driver must have finished any outstanding requests first
571 * via blk_cleanup_queue().
573 static void blk_release_queue(struct kobject
*kobj
)
575 struct request_queue
*q
=
576 container_of(kobj
, struct request_queue
, kobj
);
578 bdi_exit(&q
->backing_dev_info
);
582 spin_lock_irq(q
->queue_lock
);
584 spin_unlock_irq(q
->queue_lock
);
585 elevator_exit(q
->elevator
);
588 blk_exit_rl(&q
->root_rl
);
591 __blk_queue_free_tags(q
);
594 blk_free_flush_queue(q
->fq
);
598 blk_trace_shutdown(q
);
601 bioset_free(q
->bio_split
);
603 ida_simple_remove(&blk_queue_ida
, q
->id
);
604 call_rcu(&q
->rcu_head
, blk_free_queue_rcu
);
607 static const struct sysfs_ops queue_sysfs_ops
= {
608 .show
= queue_attr_show
,
609 .store
= queue_attr_store
,
612 struct kobj_type blk_queue_ktype
= {
613 .sysfs_ops
= &queue_sysfs_ops
,
614 .default_attrs
= default_attrs
,
615 .release
= blk_release_queue
,
618 int blk_register_queue(struct gendisk
*disk
)
621 struct device
*dev
= disk_to_dev(disk
);
622 struct request_queue
*q
= disk
->queue
;
628 * SCSI probing may synchronously create and destroy a lot of
629 * request_queues for non-existent devices. Shutting down a fully
630 * functional queue takes measureable wallclock time as RCU grace
631 * periods are involved. To avoid excessive latency in these
632 * cases, a request_queue starts out in a degraded mode which is
633 * faster to shut down and is made fully functional here as
634 * request_queues for non-existent devices never get registered.
636 if (!blk_queue_init_done(q
)) {
637 queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE
, q
);
638 percpu_ref_switch_to_percpu(&q
->q_usage_counter
);
639 blk_queue_bypass_end(q
);
642 ret
= blk_trace_init_sysfs(dev
);
646 ret
= kobject_add(&q
->kobj
, kobject_get(&dev
->kobj
), "%s", "queue");
648 blk_trace_remove_sysfs(dev
);
652 kobject_uevent(&q
->kobj
, KOBJ_ADD
);
655 blk_mq_register_disk(disk
);
660 ret
= elv_register_queue(q
);
662 kobject_uevent(&q
->kobj
, KOBJ_REMOVE
);
663 kobject_del(&q
->kobj
);
664 blk_trace_remove_sysfs(dev
);
665 kobject_put(&dev
->kobj
);
672 void blk_unregister_queue(struct gendisk
*disk
)
674 struct request_queue
*q
= disk
->queue
;
680 blk_mq_unregister_disk(disk
);
683 elv_unregister_queue(q
);
685 kobject_uevent(&q
->kobj
, KOBJ_REMOVE
);
686 kobject_del(&q
->kobj
);
687 blk_trace_remove_sysfs(disk_to_dev(disk
));
688 kobject_put(&disk_to_dev(disk
)->kobj
);