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Merge tag 'pm-6.16-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
[linux-block.git] / block / genhd.c
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * gendisk handling
4 *
5 * Portions Copyright (C) 2020 Christoph Hellwig
6 */
7
8#include <linux/module.h>
9#include <linux/ctype.h>
10#include <linux/fs.h>
11#include <linux/kdev_t.h>
12#include <linux/kernel.h>
13#include <linux/blkdev.h>
14#include <linux/backing-dev.h>
15#include <linux/init.h>
16#include <linux/spinlock.h>
17#include <linux/proc_fs.h>
18#include <linux/seq_file.h>
19#include <linux/slab.h>
20#include <linux/kmod.h>
21#include <linux/major.h>
22#include <linux/mutex.h>
23#include <linux/idr.h>
24#include <linux/log2.h>
25#include <linux/pm_runtime.h>
26#include <linux/badblocks.h>
27#include <linux/part_stat.h>
28#include <linux/blktrace_api.h>
29
30#include "blk-throttle.h"
31#include "blk.h"
32#include "blk-mq-sched.h"
33#include "blk-rq-qos.h"
34#include "blk-cgroup.h"
35
36static struct kobject *block_depr;
37
38/*
39 * Unique, monotonically increasing sequential number associated with block
40 * devices instances (i.e. incremented each time a device is attached).
41 * Associating uevents with block devices in userspace is difficult and racy:
42 * the uevent netlink socket is lossy, and on slow and overloaded systems has
43 * a very high latency.
44 * Block devices do not have exclusive owners in userspace, any process can set
45 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
46 * can be reused again and again).
47 * A userspace process setting up a block device and watching for its events
48 * cannot thus reliably tell whether an event relates to the device it just set
49 * up or another earlier instance with the same name.
50 * This sequential number allows userspace processes to solve this problem, and
51 * uniquely associate an uevent to the lifetime to a device.
52 */
53static atomic64_t diskseq;
54
55/* for extended dynamic devt allocation, currently only one major is used */
56#define NR_EXT_DEVT (1 << MINORBITS)
57static DEFINE_IDA(ext_devt_ida);
58
59void set_capacity(struct gendisk *disk, sector_t sectors)
60{
61 if (sectors > BLK_DEV_MAX_SECTORS) {
62 pr_warn_once("%s: truncate capacity from %lld to %lld\n",
63 disk->disk_name, sectors,
64 BLK_DEV_MAX_SECTORS);
65 sectors = BLK_DEV_MAX_SECTORS;
66 }
67
68 bdev_set_nr_sectors(disk->part0, sectors);
69}
70EXPORT_SYMBOL(set_capacity);
71
72/*
73 * Set disk capacity and notify if the size is not currently zero and will not
74 * be set to zero. Returns true if a uevent was sent, otherwise false.
75 */
76bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
77{
78 sector_t capacity = get_capacity(disk);
79 char *envp[] = { "RESIZE=1", NULL };
80
81 set_capacity(disk, size);
82
83 /*
84 * Only print a message and send a uevent if the gendisk is user visible
85 * and alive. This avoids spamming the log and udev when setting the
86 * initial capacity during probing.
87 */
88 if (size == capacity ||
89 !disk_live(disk) ||
90 (disk->flags & GENHD_FL_HIDDEN))
91 return false;
92
93 pr_info("%s: detected capacity change from %lld to %lld\n",
94 disk->disk_name, capacity, size);
95
96 /*
97 * Historically we did not send a uevent for changes to/from an empty
98 * device.
99 */
100 if (!capacity || !size)
101 return false;
102 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
103 return true;
104}
105EXPORT_SYMBOL_GPL(set_capacity_and_notify);
106
107static void part_stat_read_all(struct block_device *part,
108 struct disk_stats *stat)
109{
110 int cpu;
111
112 memset(stat, 0, sizeof(struct disk_stats));
113 for_each_possible_cpu(cpu) {
114 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
115 int group;
116
117 for (group = 0; group < NR_STAT_GROUPS; group++) {
118 stat->nsecs[group] += ptr->nsecs[group];
119 stat->sectors[group] += ptr->sectors[group];
120 stat->ios[group] += ptr->ios[group];
121 stat->merges[group] += ptr->merges[group];
122 }
123
124 stat->io_ticks += ptr->io_ticks;
125 }
126}
127
128static void bdev_count_inflight_rw(struct block_device *part,
129 unsigned int inflight[2], bool mq_driver)
130{
131 int write = 0;
132 int read = 0;
133 int cpu;
134
135 if (mq_driver) {
136 blk_mq_in_driver_rw(part, inflight);
137 return;
138 }
139
140 for_each_possible_cpu(cpu) {
141 read += part_stat_local_read_cpu(part, in_flight[READ], cpu);
142 write += part_stat_local_read_cpu(part, in_flight[WRITE], cpu);
143 }
144
145 /*
146 * While iterating all CPUs, some IOs may be issued from a CPU already
147 * traversed and complete on a CPU that has not yet been traversed,
148 * causing the inflight number to be negative.
149 */
150 inflight[READ] = read > 0 ? read : 0;
151 inflight[WRITE] = write > 0 ? write : 0;
152}
153
154/**
155 * bdev_count_inflight - get the number of inflight IOs for a block device.
156 *
157 * @part: the block device.
158 *
159 * Inflight here means started IO accounting, from bdev_start_io_acct() for
160 * bio-based block device, and from blk_account_io_start() for rq-based block
161 * device.
162 */
163unsigned int bdev_count_inflight(struct block_device *part)
164{
165 unsigned int inflight[2] = {0};
166
167 bdev_count_inflight_rw(part, inflight, false);
168
169 return inflight[READ] + inflight[WRITE];
170}
171EXPORT_SYMBOL_GPL(bdev_count_inflight);
172
173/*
174 * Can be deleted altogether. Later.
175 *
176 */
177#define BLKDEV_MAJOR_HASH_SIZE 255
178static struct blk_major_name {
179 struct blk_major_name *next;
180 int major;
181 char name[16];
182#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
183 void (*probe)(dev_t devt);
184#endif
185} *major_names[BLKDEV_MAJOR_HASH_SIZE];
186static DEFINE_MUTEX(major_names_lock);
187static DEFINE_SPINLOCK(major_names_spinlock);
188
189/* index in the above - for now: assume no multimajor ranges */
190static inline int major_to_index(unsigned major)
191{
192 return major % BLKDEV_MAJOR_HASH_SIZE;
193}
194
195#ifdef CONFIG_PROC_FS
196void blkdev_show(struct seq_file *seqf, off_t offset)
197{
198 struct blk_major_name *dp;
199
200 spin_lock(&major_names_spinlock);
201 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
202 if (dp->major == offset)
203 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
204 spin_unlock(&major_names_spinlock);
205}
206#endif /* CONFIG_PROC_FS */
207
208/**
209 * __register_blkdev - register a new block device
210 *
211 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
212 * @major = 0, try to allocate any unused major number.
213 * @name: the name of the new block device as a zero terminated string
214 * @probe: pre-devtmpfs / pre-udev callback used to create disks when their
215 * pre-created device node is accessed. When a probe call uses
216 * add_disk() and it fails the driver must cleanup resources. This
217 * interface may soon be removed.
218 *
219 * The @name must be unique within the system.
220 *
221 * The return value depends on the @major input parameter:
222 *
223 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
224 * then the function returns zero on success, or a negative error code
225 * - if any unused major number was requested with @major = 0 parameter
226 * then the return value is the allocated major number in range
227 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
228 *
229 * See Documentation/admin-guide/devices.txt for the list of allocated
230 * major numbers.
231 *
232 * Use register_blkdev instead for any new code.
233 */
234int __register_blkdev(unsigned int major, const char *name,
235 void (*probe)(dev_t devt))
236{
237 struct blk_major_name **n, *p;
238 int index, ret = 0;
239
240 mutex_lock(&major_names_lock);
241
242 /* temporary */
243 if (major == 0) {
244 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
245 if (major_names[index] == NULL)
246 break;
247 }
248
249 if (index == 0) {
250 printk("%s: failed to get major for %s\n",
251 __func__, name);
252 ret = -EBUSY;
253 goto out;
254 }
255 major = index;
256 ret = major;
257 }
258
259 if (major >= BLKDEV_MAJOR_MAX) {
260 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
261 __func__, major, BLKDEV_MAJOR_MAX-1, name);
262
263 ret = -EINVAL;
264 goto out;
265 }
266
267 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
268 if (p == NULL) {
269 ret = -ENOMEM;
270 goto out;
271 }
272
273 p->major = major;
274#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
275 p->probe = probe;
276#endif
277 strscpy(p->name, name, sizeof(p->name));
278 p->next = NULL;
279 index = major_to_index(major);
280
281 spin_lock(&major_names_spinlock);
282 for (n = &major_names[index]; *n; n = &(*n)->next) {
283 if ((*n)->major == major)
284 break;
285 }
286 if (!*n)
287 *n = p;
288 else
289 ret = -EBUSY;
290 spin_unlock(&major_names_spinlock);
291
292 if (ret < 0) {
293 printk("register_blkdev: cannot get major %u for %s\n",
294 major, name);
295 kfree(p);
296 }
297out:
298 mutex_unlock(&major_names_lock);
299 return ret;
300}
301EXPORT_SYMBOL(__register_blkdev);
302
303void unregister_blkdev(unsigned int major, const char *name)
304{
305 struct blk_major_name **n;
306 struct blk_major_name *p = NULL;
307 int index = major_to_index(major);
308
309 mutex_lock(&major_names_lock);
310 spin_lock(&major_names_spinlock);
311 for (n = &major_names[index]; *n; n = &(*n)->next)
312 if ((*n)->major == major)
313 break;
314 if (!*n || strcmp((*n)->name, name)) {
315 WARN_ON(1);
316 } else {
317 p = *n;
318 *n = p->next;
319 }
320 spin_unlock(&major_names_spinlock);
321 mutex_unlock(&major_names_lock);
322 kfree(p);
323}
324
325EXPORT_SYMBOL(unregister_blkdev);
326
327int blk_alloc_ext_minor(void)
328{
329 int idx;
330
331 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT - 1, GFP_KERNEL);
332 if (idx == -ENOSPC)
333 return -EBUSY;
334 return idx;
335}
336
337void blk_free_ext_minor(unsigned int minor)
338{
339 ida_free(&ext_devt_ida, minor);
340}
341
342void disk_uevent(struct gendisk *disk, enum kobject_action action)
343{
344 struct block_device *part;
345 unsigned long idx;
346
347 rcu_read_lock();
348 xa_for_each(&disk->part_tbl, idx, part) {
349 if (bdev_is_partition(part) && !bdev_nr_sectors(part))
350 continue;
351 if (!kobject_get_unless_zero(&part->bd_device.kobj))
352 continue;
353
354 rcu_read_unlock();
355 kobject_uevent(bdev_kobj(part), action);
356 put_device(&part->bd_device);
357 rcu_read_lock();
358 }
359 rcu_read_unlock();
360}
361EXPORT_SYMBOL_GPL(disk_uevent);
362
363int disk_scan_partitions(struct gendisk *disk, blk_mode_t mode)
364{
365 struct file *file;
366 int ret = 0;
367
368 if (!disk_has_partscan(disk))
369 return -EINVAL;
370 if (disk->open_partitions)
371 return -EBUSY;
372
373 /*
374 * If the device is opened exclusively by current thread already, it's
375 * safe to scan partitons, otherwise, use bd_prepare_to_claim() to
376 * synchronize with other exclusive openers and other partition
377 * scanners.
378 */
379 if (!(mode & BLK_OPEN_EXCL)) {
380 ret = bd_prepare_to_claim(disk->part0, disk_scan_partitions,
381 NULL);
382 if (ret)
383 return ret;
384 }
385
386 set_bit(GD_NEED_PART_SCAN, &disk->state);
387 file = bdev_file_open_by_dev(disk_devt(disk), mode & ~BLK_OPEN_EXCL,
388 NULL, NULL);
389 if (IS_ERR(file))
390 ret = PTR_ERR(file);
391 else
392 fput(file);
393
394 /*
395 * If blkdev_get_by_dev() failed early, GD_NEED_PART_SCAN is still set,
396 * and this will cause that re-assemble partitioned raid device will
397 * creat partition for underlying disk.
398 */
399 clear_bit(GD_NEED_PART_SCAN, &disk->state);
400 if (!(mode & BLK_OPEN_EXCL))
401 bd_abort_claiming(disk->part0, disk_scan_partitions);
402 return ret;
403}
404
405static void add_disk_final(struct gendisk *disk)
406{
407 struct device *ddev = disk_to_dev(disk);
408
409 if (!(disk->flags & GENHD_FL_HIDDEN)) {
410 /* Make sure the first partition scan will be proceed */
411 if (get_capacity(disk) && disk_has_partscan(disk))
412 set_bit(GD_NEED_PART_SCAN, &disk->state);
413
414 bdev_add(disk->part0, ddev->devt);
415 if (get_capacity(disk))
416 disk_scan_partitions(disk, BLK_OPEN_READ);
417
418 /*
419 * Announce the disk and partitions after all partitions are
420 * created. (for hidden disks uevents remain suppressed forever)
421 */
422 dev_set_uevent_suppress(ddev, 0);
423 disk_uevent(disk, KOBJ_ADD);
424 }
425
426 blk_apply_bdi_limits(disk->bdi, &disk->queue->limits);
427 disk_add_events(disk);
428 set_bit(GD_ADDED, &disk->state);
429}
430
431static int __add_disk(struct device *parent, struct gendisk *disk,
432 const struct attribute_group **groups,
433 struct fwnode_handle *fwnode)
434
435{
436 struct device *ddev = disk_to_dev(disk);
437 int ret;
438
439 if (WARN_ON_ONCE(bdev_nr_sectors(disk->part0) > BLK_DEV_MAX_SECTORS))
440 return -EINVAL;
441
442 if (queue_is_mq(disk->queue)) {
443 /*
444 * ->submit_bio and ->poll_bio are bypassed for blk-mq drivers.
445 */
446 if (disk->fops->submit_bio || disk->fops->poll_bio)
447 return -EINVAL;
448 } else {
449 if (!disk->fops->submit_bio)
450 return -EINVAL;
451 bdev_set_flag(disk->part0, BD_HAS_SUBMIT_BIO);
452 }
453
454 /*
455 * If the driver provides an explicit major number it also must provide
456 * the number of minors numbers supported, and those will be used to
457 * setup the gendisk.
458 * Otherwise just allocate the device numbers for both the whole device
459 * and all partitions from the extended dev_t space.
460 */
461 ret = -EINVAL;
462 if (disk->major) {
463 if (WARN_ON(!disk->minors))
464 goto out;
465
466 if (disk->minors > DISK_MAX_PARTS) {
467 pr_err("block: can't allocate more than %d partitions\n",
468 DISK_MAX_PARTS);
469 disk->minors = DISK_MAX_PARTS;
470 }
471 if (disk->first_minor > MINORMASK ||
472 disk->minors > MINORMASK + 1 ||
473 disk->first_minor + disk->minors > MINORMASK + 1)
474 goto out;
475 } else {
476 if (WARN_ON(disk->minors))
477 goto out;
478
479 ret = blk_alloc_ext_minor();
480 if (ret < 0)
481 goto out;
482 disk->major = BLOCK_EXT_MAJOR;
483 disk->first_minor = ret;
484 }
485
486 /* delay uevents, until we scanned partition table */
487 dev_set_uevent_suppress(ddev, 1);
488
489 ddev->parent = parent;
490 ddev->groups = groups;
491 dev_set_name(ddev, "%s", disk->disk_name);
492 if (fwnode)
493 device_set_node(ddev, fwnode);
494 if (!(disk->flags & GENHD_FL_HIDDEN))
495 ddev->devt = MKDEV(disk->major, disk->first_minor);
496 ret = device_add(ddev);
497 if (ret)
498 goto out_free_ext_minor;
499
500 ret = disk_alloc_events(disk);
501 if (ret)
502 goto out_device_del;
503
504 ret = sysfs_create_link(block_depr, &ddev->kobj,
505 kobject_name(&ddev->kobj));
506 if (ret)
507 goto out_device_del;
508
509 /*
510 * avoid probable deadlock caused by allocating memory with
511 * GFP_KERNEL in runtime_resume callback of its all ancestor
512 * devices
513 */
514 pm_runtime_set_memalloc_noio(ddev, true);
515
516 disk->part0->bd_holder_dir =
517 kobject_create_and_add("holders", &ddev->kobj);
518 if (!disk->part0->bd_holder_dir) {
519 ret = -ENOMEM;
520 goto out_del_block_link;
521 }
522 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
523 if (!disk->slave_dir) {
524 ret = -ENOMEM;
525 goto out_put_holder_dir;
526 }
527
528 ret = blk_register_queue(disk);
529 if (ret)
530 goto out_put_slave_dir;
531
532 if (!(disk->flags & GENHD_FL_HIDDEN)) {
533 ret = bdi_register(disk->bdi, "%u:%u",
534 disk->major, disk->first_minor);
535 if (ret)
536 goto out_unregister_queue;
537 bdi_set_owner(disk->bdi, ddev);
538 ret = sysfs_create_link(&ddev->kobj,
539 &disk->bdi->dev->kobj, "bdi");
540 if (ret)
541 goto out_unregister_bdi;
542 } else {
543 /*
544 * Even if the block_device for a hidden gendisk is not
545 * registered, it needs to have a valid bd_dev so that the
546 * freeing of the dynamic major works.
547 */
548 disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor);
549 }
550 return 0;
551
552out_unregister_bdi:
553 if (!(disk->flags & GENHD_FL_HIDDEN))
554 bdi_unregister(disk->bdi);
555out_unregister_queue:
556 blk_unregister_queue(disk);
557 rq_qos_exit(disk->queue);
558out_put_slave_dir:
559 kobject_put(disk->slave_dir);
560 disk->slave_dir = NULL;
561out_put_holder_dir:
562 kobject_put(disk->part0->bd_holder_dir);
563out_del_block_link:
564 sysfs_remove_link(block_depr, dev_name(ddev));
565 pm_runtime_set_memalloc_noio(ddev, false);
566out_device_del:
567 device_del(ddev);
568out_free_ext_minor:
569 if (disk->major == BLOCK_EXT_MAJOR)
570 blk_free_ext_minor(disk->first_minor);
571out:
572 return ret;
573}
574
575/**
576 * add_disk_fwnode - add disk information to kernel list with fwnode
577 * @parent: parent device for the disk
578 * @disk: per-device partitioning information
579 * @groups: Additional per-device sysfs groups
580 * @fwnode: attached disk fwnode
581 *
582 * This function registers the partitioning information in @disk
583 * with the kernel. Also attach a fwnode to the disk device.
584 */
585int __must_check add_disk_fwnode(struct device *parent, struct gendisk *disk,
586 const struct attribute_group **groups,
587 struct fwnode_handle *fwnode)
588{
589 struct blk_mq_tag_set *set;
590 unsigned int memflags;
591 int ret;
592
593 if (queue_is_mq(disk->queue)) {
594 set = disk->queue->tag_set;
595 memflags = memalloc_noio_save();
596 down_read(&set->update_nr_hwq_lock);
597 ret = __add_disk(parent, disk, groups, fwnode);
598 up_read(&set->update_nr_hwq_lock);
599 memalloc_noio_restore(memflags);
600 } else {
601 ret = __add_disk(parent, disk, groups, fwnode);
602 }
603
604 /*
605 * add_disk_final() needn't to read `nr_hw_queues`, so move it out
606 * of read lock `set->update_nr_hwq_lock` for avoiding unnecessary
607 * lock dependency on `disk->open_mutex` from scanning partition.
608 */
609 if (!ret)
610 add_disk_final(disk);
611 return ret;
612}
613EXPORT_SYMBOL_GPL(add_disk_fwnode);
614
615/**
616 * device_add_disk - add disk information to kernel list
617 * @parent: parent device for the disk
618 * @disk: per-device partitioning information
619 * @groups: Additional per-device sysfs groups
620 *
621 * This function registers the partitioning information in @disk
622 * with the kernel.
623 */
624int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
625 const struct attribute_group **groups)
626{
627 return add_disk_fwnode(parent, disk, groups, NULL);
628}
629EXPORT_SYMBOL(device_add_disk);
630
631static void blk_report_disk_dead(struct gendisk *disk, bool surprise)
632{
633 struct block_device *bdev;
634 unsigned long idx;
635
636 /*
637 * On surprise disk removal, bdev_mark_dead() may call into file
638 * systems below. Make it clear that we're expecting to not hold
639 * disk->open_mutex.
640 */
641 lockdep_assert_not_held(&disk->open_mutex);
642
643 rcu_read_lock();
644 xa_for_each(&disk->part_tbl, idx, bdev) {
645 if (!kobject_get_unless_zero(&bdev->bd_device.kobj))
646 continue;
647 rcu_read_unlock();
648
649 bdev_mark_dead(bdev, surprise);
650
651 put_device(&bdev->bd_device);
652 rcu_read_lock();
653 }
654 rcu_read_unlock();
655}
656
657static bool __blk_mark_disk_dead(struct gendisk *disk)
658{
659 /*
660 * Fail any new I/O.
661 */
662 if (test_and_set_bit(GD_DEAD, &disk->state))
663 return false;
664
665 if (test_bit(GD_OWNS_QUEUE, &disk->state))
666 blk_queue_flag_set(QUEUE_FLAG_DYING, disk->queue);
667
668 /*
669 * Stop buffered writers from dirtying pages that can't be written out.
670 */
671 set_capacity(disk, 0);
672
673 /*
674 * Prevent new I/O from crossing bio_queue_enter().
675 */
676 return blk_queue_start_drain(disk->queue);
677}
678
679/**
680 * blk_mark_disk_dead - mark a disk as dead
681 * @disk: disk to mark as dead
682 *
683 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O
684 * to this disk.
685 */
686void blk_mark_disk_dead(struct gendisk *disk)
687{
688 __blk_mark_disk_dead(disk);
689 blk_report_disk_dead(disk, true);
690}
691EXPORT_SYMBOL_GPL(blk_mark_disk_dead);
692
693static void __del_gendisk(struct gendisk *disk)
694{
695 struct request_queue *q = disk->queue;
696 struct block_device *part;
697 unsigned long idx;
698 bool start_drain;
699
700 might_sleep();
701
702 if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN)))
703 return;
704
705 disk_del_events(disk);
706
707 /*
708 * Prevent new openers by unlinked the bdev inode.
709 */
710 mutex_lock(&disk->open_mutex);
711 xa_for_each(&disk->part_tbl, idx, part)
712 bdev_unhash(part);
713 mutex_unlock(&disk->open_mutex);
714
715 /*
716 * Tell the file system to write back all dirty data and shut down if
717 * it hasn't been notified earlier.
718 */
719 if (!test_bit(GD_DEAD, &disk->state))
720 blk_report_disk_dead(disk, false);
721
722 /*
723 * Drop all partitions now that the disk is marked dead.
724 */
725 mutex_lock(&disk->open_mutex);
726 start_drain = __blk_mark_disk_dead(disk);
727 if (start_drain)
728 blk_freeze_acquire_lock(q);
729 xa_for_each_start(&disk->part_tbl, idx, part, 1)
730 drop_partition(part);
731 mutex_unlock(&disk->open_mutex);
732
733 if (!(disk->flags & GENHD_FL_HIDDEN)) {
734 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
735
736 /*
737 * Unregister bdi before releasing device numbers (as they can
738 * get reused and we'd get clashes in sysfs).
739 */
740 bdi_unregister(disk->bdi);
741 }
742
743 blk_unregister_queue(disk);
744
745 kobject_put(disk->part0->bd_holder_dir);
746 kobject_put(disk->slave_dir);
747 disk->slave_dir = NULL;
748
749 part_stat_set_all(disk->part0, 0);
750 disk->part0->bd_stamp = 0;
751 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
752 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
753 device_del(disk_to_dev(disk));
754
755 blk_mq_freeze_queue_wait(q);
756
757 blk_throtl_cancel_bios(disk);
758
759 blk_sync_queue(q);
760 blk_flush_integrity();
761
762 if (queue_is_mq(q))
763 blk_mq_cancel_work_sync(q);
764
765 rq_qos_exit(q);
766
767 /*
768 * If the disk does not own the queue, allow using passthrough requests
769 * again. Else leave the queue frozen to fail all I/O.
770 */
771 if (!test_bit(GD_OWNS_QUEUE, &disk->state))
772 __blk_mq_unfreeze_queue(q, true);
773 else if (queue_is_mq(q))
774 blk_mq_exit_queue(q);
775
776 if (start_drain)
777 blk_unfreeze_release_lock(q);
778}
779
780static void disable_elv_switch(struct request_queue *q)
781{
782 struct blk_mq_tag_set *set = q->tag_set;
783 WARN_ON_ONCE(!queue_is_mq(q));
784
785 down_write(&set->update_nr_hwq_lock);
786 blk_queue_flag_set(QUEUE_FLAG_NO_ELV_SWITCH, q);
787 up_write(&set->update_nr_hwq_lock);
788}
789
790/**
791 * del_gendisk - remove the gendisk
792 * @disk: the struct gendisk to remove
793 *
794 * Removes the gendisk and all its associated resources. This deletes the
795 * partitions associated with the gendisk, and unregisters the associated
796 * request_queue.
797 *
798 * This is the counter to the respective __device_add_disk() call.
799 *
800 * The final removal of the struct gendisk happens when its refcount reaches 0
801 * with put_disk(), which should be called after del_gendisk(), if
802 * __device_add_disk() was used.
803 *
804 * Drivers exist which depend on the release of the gendisk to be synchronous,
805 * it should not be deferred.
806 *
807 * Context: can sleep
808 */
809void del_gendisk(struct gendisk *disk)
810{
811 struct blk_mq_tag_set *set;
812 unsigned int memflags;
813
814 if (!queue_is_mq(disk->queue)) {
815 __del_gendisk(disk);
816 } else {
817 set = disk->queue->tag_set;
818
819 disable_elv_switch(disk->queue);
820
821 memflags = memalloc_noio_save();
822 down_read(&set->update_nr_hwq_lock);
823 __del_gendisk(disk);
824 up_read(&set->update_nr_hwq_lock);
825 memalloc_noio_restore(memflags);
826 }
827}
828EXPORT_SYMBOL(del_gendisk);
829
830/**
831 * invalidate_disk - invalidate the disk
832 * @disk: the struct gendisk to invalidate
833 *
834 * A helper to invalidates the disk. It will clean the disk's associated
835 * buffer/page caches and reset its internal states so that the disk
836 * can be reused by the drivers.
837 *
838 * Context: can sleep
839 */
840void invalidate_disk(struct gendisk *disk)
841{
842 struct block_device *bdev = disk->part0;
843
844 invalidate_bdev(bdev);
845 bdev->bd_mapping->wb_err = 0;
846 set_capacity(disk, 0);
847}
848EXPORT_SYMBOL(invalidate_disk);
849
850/* sysfs access to bad-blocks list. */
851static ssize_t disk_badblocks_show(struct device *dev,
852 struct device_attribute *attr,
853 char *page)
854{
855 struct gendisk *disk = dev_to_disk(dev);
856
857 if (!disk->bb)
858 return sysfs_emit(page, "\n");
859
860 return badblocks_show(disk->bb, page, 0);
861}
862
863static ssize_t disk_badblocks_store(struct device *dev,
864 struct device_attribute *attr,
865 const char *page, size_t len)
866{
867 struct gendisk *disk = dev_to_disk(dev);
868
869 if (!disk->bb)
870 return -ENXIO;
871
872 return badblocks_store(disk->bb, page, len, 0);
873}
874
875#ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
876static bool blk_probe_dev(dev_t devt)
877{
878 unsigned int major = MAJOR(devt);
879 struct blk_major_name **n;
880
881 mutex_lock(&major_names_lock);
882 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
883 if ((*n)->major == major && (*n)->probe) {
884 (*n)->probe(devt);
885 mutex_unlock(&major_names_lock);
886 return true;
887 }
888 }
889 mutex_unlock(&major_names_lock);
890 return false;
891}
892
893void blk_request_module(dev_t devt)
894{
895 int error;
896
897 if (blk_probe_dev(devt))
898 return;
899
900 error = request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt));
901 /* Make old-style 2.4 aliases work */
902 if (error > 0)
903 error = request_module("block-major-%d", MAJOR(devt));
904 if (!error)
905 blk_probe_dev(devt);
906}
907#endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */
908
909#ifdef CONFIG_PROC_FS
910/* iterator */
911static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
912{
913 loff_t skip = *pos;
914 struct class_dev_iter *iter;
915 struct device *dev;
916
917 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
918 if (!iter)
919 return ERR_PTR(-ENOMEM);
920
921 seqf->private = iter;
922 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
923 do {
924 dev = class_dev_iter_next(iter);
925 if (!dev)
926 return NULL;
927 } while (skip--);
928
929 return dev_to_disk(dev);
930}
931
932static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
933{
934 struct device *dev;
935
936 (*pos)++;
937 dev = class_dev_iter_next(seqf->private);
938 if (dev)
939 return dev_to_disk(dev);
940
941 return NULL;
942}
943
944static void disk_seqf_stop(struct seq_file *seqf, void *v)
945{
946 struct class_dev_iter *iter = seqf->private;
947
948 /* stop is called even after start failed :-( */
949 if (iter) {
950 class_dev_iter_exit(iter);
951 kfree(iter);
952 seqf->private = NULL;
953 }
954}
955
956static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
957{
958 void *p;
959
960 p = disk_seqf_start(seqf, pos);
961 if (!IS_ERR_OR_NULL(p) && !*pos)
962 seq_puts(seqf, "major minor #blocks name\n\n");
963 return p;
964}
965
966static int show_partition(struct seq_file *seqf, void *v)
967{
968 struct gendisk *sgp = v;
969 struct block_device *part;
970 unsigned long idx;
971
972 if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN))
973 return 0;
974
975 rcu_read_lock();
976 xa_for_each(&sgp->part_tbl, idx, part) {
977 if (!bdev_nr_sectors(part))
978 continue;
979 seq_printf(seqf, "%4d %7d %10llu %pg\n",
980 MAJOR(part->bd_dev), MINOR(part->bd_dev),
981 bdev_nr_sectors(part) >> 1, part);
982 }
983 rcu_read_unlock();
984 return 0;
985}
986
987static const struct seq_operations partitions_op = {
988 .start = show_partition_start,
989 .next = disk_seqf_next,
990 .stop = disk_seqf_stop,
991 .show = show_partition
992};
993#endif
994
995static int __init genhd_device_init(void)
996{
997 int error;
998
999 error = class_register(&block_class);
1000 if (unlikely(error))
1001 return error;
1002 blk_dev_init();
1003
1004 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
1005
1006 /* create top-level block dir */
1007 block_depr = kobject_create_and_add("block", NULL);
1008 return 0;
1009}
1010
1011subsys_initcall(genhd_device_init);
1012
1013static ssize_t disk_range_show(struct device *dev,
1014 struct device_attribute *attr, char *buf)
1015{
1016 struct gendisk *disk = dev_to_disk(dev);
1017
1018 return sysfs_emit(buf, "%d\n", disk->minors);
1019}
1020
1021static ssize_t disk_ext_range_show(struct device *dev,
1022 struct device_attribute *attr, char *buf)
1023{
1024 struct gendisk *disk = dev_to_disk(dev);
1025
1026 return sysfs_emit(buf, "%d\n",
1027 (disk->flags & GENHD_FL_NO_PART) ? 1 : DISK_MAX_PARTS);
1028}
1029
1030static ssize_t disk_removable_show(struct device *dev,
1031 struct device_attribute *attr, char *buf)
1032{
1033 struct gendisk *disk = dev_to_disk(dev);
1034
1035 return sysfs_emit(buf, "%d\n",
1036 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
1037}
1038
1039static ssize_t disk_hidden_show(struct device *dev,
1040 struct device_attribute *attr, char *buf)
1041{
1042 struct gendisk *disk = dev_to_disk(dev);
1043
1044 return sysfs_emit(buf, "%d\n",
1045 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
1046}
1047
1048static ssize_t disk_ro_show(struct device *dev,
1049 struct device_attribute *attr, char *buf)
1050{
1051 struct gendisk *disk = dev_to_disk(dev);
1052
1053 return sysfs_emit(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1054}
1055
1056ssize_t part_size_show(struct device *dev,
1057 struct device_attribute *attr, char *buf)
1058{
1059 return sysfs_emit(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
1060}
1061
1062ssize_t part_stat_show(struct device *dev,
1063 struct device_attribute *attr, char *buf)
1064{
1065 struct block_device *bdev = dev_to_bdev(dev);
1066 struct disk_stats stat;
1067 unsigned int inflight;
1068
1069 inflight = bdev_count_inflight(bdev);
1070 if (inflight) {
1071 part_stat_lock();
1072 update_io_ticks(bdev, jiffies, true);
1073 part_stat_unlock();
1074 }
1075 part_stat_read_all(bdev, &stat);
1076 return sysfs_emit(buf,
1077 "%8lu %8lu %8llu %8u "
1078 "%8lu %8lu %8llu %8u "
1079 "%8u %8u %8u "
1080 "%8lu %8lu %8llu %8u "
1081 "%8lu %8u"
1082 "\n",
1083 stat.ios[STAT_READ],
1084 stat.merges[STAT_READ],
1085 (unsigned long long)stat.sectors[STAT_READ],
1086 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
1087 stat.ios[STAT_WRITE],
1088 stat.merges[STAT_WRITE],
1089 (unsigned long long)stat.sectors[STAT_WRITE],
1090 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
1091 inflight,
1092 jiffies_to_msecs(stat.io_ticks),
1093 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1094 stat.nsecs[STAT_WRITE] +
1095 stat.nsecs[STAT_DISCARD] +
1096 stat.nsecs[STAT_FLUSH],
1097 NSEC_PER_MSEC),
1098 stat.ios[STAT_DISCARD],
1099 stat.merges[STAT_DISCARD],
1100 (unsigned long long)stat.sectors[STAT_DISCARD],
1101 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
1102 stat.ios[STAT_FLUSH],
1103 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
1104}
1105
1106/*
1107 * Show the number of IOs issued to driver.
1108 * For bio-based device, started from bdev_start_io_acct();
1109 * For rq-based device, started from blk_mq_start_request();
1110 */
1111ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
1112 char *buf)
1113{
1114 struct block_device *bdev = dev_to_bdev(dev);
1115 struct request_queue *q = bdev_get_queue(bdev);
1116 unsigned int inflight[2] = {0};
1117
1118 bdev_count_inflight_rw(bdev, inflight, queue_is_mq(q));
1119
1120 return sysfs_emit(buf, "%8u %8u\n", inflight[READ], inflight[WRITE]);
1121}
1122
1123static ssize_t disk_capability_show(struct device *dev,
1124 struct device_attribute *attr, char *buf)
1125{
1126 dev_warn_once(dev, "the capability attribute has been deprecated.\n");
1127 return sysfs_emit(buf, "0\n");
1128}
1129
1130static ssize_t disk_alignment_offset_show(struct device *dev,
1131 struct device_attribute *attr,
1132 char *buf)
1133{
1134 struct gendisk *disk = dev_to_disk(dev);
1135
1136 return sysfs_emit(buf, "%d\n", bdev_alignment_offset(disk->part0));
1137}
1138
1139static ssize_t disk_discard_alignment_show(struct device *dev,
1140 struct device_attribute *attr,
1141 char *buf)
1142{
1143 struct gendisk *disk = dev_to_disk(dev);
1144
1145 return sysfs_emit(buf, "%d\n", bdev_alignment_offset(disk->part0));
1146}
1147
1148static ssize_t diskseq_show(struct device *dev,
1149 struct device_attribute *attr, char *buf)
1150{
1151 struct gendisk *disk = dev_to_disk(dev);
1152
1153 return sysfs_emit(buf, "%llu\n", disk->diskseq);
1154}
1155
1156static ssize_t partscan_show(struct device *dev,
1157 struct device_attribute *attr, char *buf)
1158{
1159 return sysfs_emit(buf, "%u\n", disk_has_partscan(dev_to_disk(dev)));
1160}
1161
1162static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1163static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1164static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1165static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1166static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1167static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1168static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1169static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1170static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1171static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1172static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1173static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1174static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);
1175static DEVICE_ATTR(partscan, 0444, partscan_show, NULL);
1176
1177#ifdef CONFIG_FAIL_MAKE_REQUEST
1178ssize_t part_fail_show(struct device *dev,
1179 struct device_attribute *attr, char *buf)
1180{
1181 return sysfs_emit(buf, "%d\n",
1182 bdev_test_flag(dev_to_bdev(dev), BD_MAKE_IT_FAIL));
1183}
1184
1185ssize_t part_fail_store(struct device *dev,
1186 struct device_attribute *attr,
1187 const char *buf, size_t count)
1188{
1189 int i;
1190
1191 if (count > 0 && sscanf(buf, "%d", &i) > 0) {
1192 if (i)
1193 bdev_set_flag(dev_to_bdev(dev), BD_MAKE_IT_FAIL);
1194 else
1195 bdev_clear_flag(dev_to_bdev(dev), BD_MAKE_IT_FAIL);
1196 }
1197 return count;
1198}
1199
1200static struct device_attribute dev_attr_fail =
1201 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1202#endif /* CONFIG_FAIL_MAKE_REQUEST */
1203
1204#ifdef CONFIG_FAIL_IO_TIMEOUT
1205static struct device_attribute dev_attr_fail_timeout =
1206 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1207#endif
1208
1209static struct attribute *disk_attrs[] = {
1210 &dev_attr_range.attr,
1211 &dev_attr_ext_range.attr,
1212 &dev_attr_removable.attr,
1213 &dev_attr_hidden.attr,
1214 &dev_attr_ro.attr,
1215 &dev_attr_size.attr,
1216 &dev_attr_alignment_offset.attr,
1217 &dev_attr_discard_alignment.attr,
1218 &dev_attr_capability.attr,
1219 &dev_attr_stat.attr,
1220 &dev_attr_inflight.attr,
1221 &dev_attr_badblocks.attr,
1222 &dev_attr_events.attr,
1223 &dev_attr_events_async.attr,
1224 &dev_attr_events_poll_msecs.attr,
1225 &dev_attr_diskseq.attr,
1226 &dev_attr_partscan.attr,
1227#ifdef CONFIG_FAIL_MAKE_REQUEST
1228 &dev_attr_fail.attr,
1229#endif
1230#ifdef CONFIG_FAIL_IO_TIMEOUT
1231 &dev_attr_fail_timeout.attr,
1232#endif
1233 NULL
1234};
1235
1236static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1237{
1238 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1239 struct gendisk *disk = dev_to_disk(dev);
1240
1241 if (a == &dev_attr_badblocks.attr && !disk->bb)
1242 return 0;
1243 return a->mode;
1244}
1245
1246static struct attribute_group disk_attr_group = {
1247 .attrs = disk_attrs,
1248 .is_visible = disk_visible,
1249};
1250
1251static const struct attribute_group *disk_attr_groups[] = {
1252 &disk_attr_group,
1253#ifdef CONFIG_BLK_DEV_IO_TRACE
1254 &blk_trace_attr_group,
1255#endif
1256#ifdef CONFIG_BLK_DEV_INTEGRITY
1257 &blk_integrity_attr_group,
1258#endif
1259 NULL
1260};
1261
1262/**
1263 * disk_release - releases all allocated resources of the gendisk
1264 * @dev: the device representing this disk
1265 *
1266 * This function releases all allocated resources of the gendisk.
1267 *
1268 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1269 * assigned. Since the request_queue sits on top of the gendisk for these
1270 * drivers we also call blk_put_queue() for them, and we expect the
1271 * request_queue refcount to reach 0 at this point, and so the request_queue
1272 * will also be freed prior to the disk.
1273 *
1274 * Context: can sleep
1275 */
1276static void disk_release(struct device *dev)
1277{
1278 struct gendisk *disk = dev_to_disk(dev);
1279
1280 might_sleep();
1281 WARN_ON_ONCE(disk_live(disk));
1282
1283 blk_trace_remove(disk->queue);
1284
1285 /*
1286 * To undo the all initialization from blk_mq_init_allocated_queue in
1287 * case of a probe failure where add_disk is never called we have to
1288 * call blk_mq_exit_queue here. We can't do this for the more common
1289 * teardown case (yet) as the tagset can be gone by the time the disk
1290 * is released once it was added.
1291 */
1292 if (queue_is_mq(disk->queue) &&
1293 test_bit(GD_OWNS_QUEUE, &disk->state) &&
1294 !test_bit(GD_ADDED, &disk->state))
1295 blk_mq_exit_queue(disk->queue);
1296
1297 blkcg_exit_disk(disk);
1298
1299 bioset_exit(&disk->bio_split);
1300
1301 disk_release_events(disk);
1302 kfree(disk->random);
1303 disk_free_zone_resources(disk);
1304 xa_destroy(&disk->part_tbl);
1305
1306 disk->queue->disk = NULL;
1307 blk_put_queue(disk->queue);
1308
1309 if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk)
1310 disk->fops->free_disk(disk);
1311
1312 bdev_drop(disk->part0); /* frees the disk */
1313}
1314
1315static int block_uevent(const struct device *dev, struct kobj_uevent_env *env)
1316{
1317 const struct gendisk *disk = dev_to_disk(dev);
1318
1319 return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq);
1320}
1321
1322const struct class block_class = {
1323 .name = "block",
1324 .dev_uevent = block_uevent,
1325};
1326
1327static char *block_devnode(const struct device *dev, umode_t *mode,
1328 kuid_t *uid, kgid_t *gid)
1329{
1330 struct gendisk *disk = dev_to_disk(dev);
1331
1332 if (disk->fops->devnode)
1333 return disk->fops->devnode(disk, mode);
1334 return NULL;
1335}
1336
1337const struct device_type disk_type = {
1338 .name = "disk",
1339 .groups = disk_attr_groups,
1340 .release = disk_release,
1341 .devnode = block_devnode,
1342};
1343
1344#ifdef CONFIG_PROC_FS
1345/*
1346 * aggregate disk stat collector. Uses the same stats that the sysfs
1347 * entries do, above, but makes them available through one seq_file.
1348 *
1349 * The output looks suspiciously like /proc/partitions with a bunch of
1350 * extra fields.
1351 */
1352static int diskstats_show(struct seq_file *seqf, void *v)
1353{
1354 struct gendisk *gp = v;
1355 struct block_device *hd;
1356 unsigned int inflight;
1357 struct disk_stats stat;
1358 unsigned long idx;
1359
1360 /*
1361 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1362 seq_puts(seqf, "major minor name"
1363 " rio rmerge rsect ruse wio wmerge "
1364 "wsect wuse running use aveq"
1365 "\n\n");
1366 */
1367
1368 rcu_read_lock();
1369 xa_for_each(&gp->part_tbl, idx, hd) {
1370 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
1371 continue;
1372
1373 inflight = bdev_count_inflight(hd);
1374 if (inflight) {
1375 part_stat_lock();
1376 update_io_ticks(hd, jiffies, true);
1377 part_stat_unlock();
1378 }
1379 part_stat_read_all(hd, &stat);
1380 seq_put_decimal_ull_width(seqf, "", MAJOR(hd->bd_dev), 4);
1381 seq_put_decimal_ull_width(seqf, " ", MINOR(hd->bd_dev), 7);
1382 seq_printf(seqf, " %pg", hd);
1383 seq_put_decimal_ull(seqf, " ", stat.ios[STAT_READ]);
1384 seq_put_decimal_ull(seqf, " ", stat.merges[STAT_READ]);
1385 seq_put_decimal_ull(seqf, " ", stat.sectors[STAT_READ]);
1386 seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_READ],
1387 NSEC_PER_MSEC));
1388 seq_put_decimal_ull(seqf, " ", stat.ios[STAT_WRITE]);
1389 seq_put_decimal_ull(seqf, " ", stat.merges[STAT_WRITE]);
1390 seq_put_decimal_ull(seqf, " ", stat.sectors[STAT_WRITE]);
1391 seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1392 NSEC_PER_MSEC));
1393 seq_put_decimal_ull(seqf, " ", inflight);
1394 seq_put_decimal_ull(seqf, " ", jiffies_to_msecs(stat.io_ticks));
1395 seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1396 stat.nsecs[STAT_WRITE] +
1397 stat.nsecs[STAT_DISCARD] +
1398 stat.nsecs[STAT_FLUSH],
1399 NSEC_PER_MSEC));
1400 seq_put_decimal_ull(seqf, " ", stat.ios[STAT_DISCARD]);
1401 seq_put_decimal_ull(seqf, " ", stat.merges[STAT_DISCARD]);
1402 seq_put_decimal_ull(seqf, " ", stat.sectors[STAT_DISCARD]);
1403 seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1404 NSEC_PER_MSEC));
1405 seq_put_decimal_ull(seqf, " ", stat.ios[STAT_FLUSH]);
1406 seq_put_decimal_ull(seqf, " ", (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1407 NSEC_PER_MSEC));
1408 seq_putc(seqf, '\n');
1409 }
1410 rcu_read_unlock();
1411
1412 return 0;
1413}
1414
1415static const struct seq_operations diskstats_op = {
1416 .start = disk_seqf_start,
1417 .next = disk_seqf_next,
1418 .stop = disk_seqf_stop,
1419 .show = diskstats_show
1420};
1421
1422static int __init proc_genhd_init(void)
1423{
1424 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1425 proc_create_seq("partitions", 0, NULL, &partitions_op);
1426 return 0;
1427}
1428module_init(proc_genhd_init);
1429#endif /* CONFIG_PROC_FS */
1430
1431dev_t part_devt(struct gendisk *disk, u8 partno)
1432{
1433 struct block_device *part;
1434 dev_t devt = 0;
1435
1436 rcu_read_lock();
1437 part = xa_load(&disk->part_tbl, partno);
1438 if (part)
1439 devt = part->bd_dev;
1440 rcu_read_unlock();
1441
1442 return devt;
1443}
1444
1445struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
1446 struct lock_class_key *lkclass)
1447{
1448 struct gendisk *disk;
1449
1450 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1451 if (!disk)
1452 return NULL;
1453
1454 if (bioset_init(&disk->bio_split, BIO_POOL_SIZE, 0, 0))
1455 goto out_free_disk;
1456
1457 disk->bdi = bdi_alloc(node_id);
1458 if (!disk->bdi)
1459 goto out_free_bioset;
1460
1461 /* bdev_alloc() might need the queue, set before the first call */
1462 disk->queue = q;
1463
1464 disk->part0 = bdev_alloc(disk, 0);
1465 if (!disk->part0)
1466 goto out_free_bdi;
1467
1468 disk->node_id = node_id;
1469 mutex_init(&disk->open_mutex);
1470 xa_init(&disk->part_tbl);
1471 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
1472 goto out_destroy_part_tbl;
1473
1474 if (blkcg_init_disk(disk))
1475 goto out_erase_part0;
1476
1477 disk_init_zone_resources(disk);
1478 rand_initialize_disk(disk);
1479 disk_to_dev(disk)->class = &block_class;
1480 disk_to_dev(disk)->type = &disk_type;
1481 device_initialize(disk_to_dev(disk));
1482 inc_diskseq(disk);
1483 q->disk = disk;
1484 lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);
1485#ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
1486 INIT_LIST_HEAD(&disk->slave_bdevs);
1487#endif
1488 mutex_init(&disk->rqos_state_mutex);
1489 return disk;
1490
1491out_erase_part0:
1492 xa_erase(&disk->part_tbl, 0);
1493out_destroy_part_tbl:
1494 xa_destroy(&disk->part_tbl);
1495 disk->part0->bd_disk = NULL;
1496 bdev_drop(disk->part0);
1497out_free_bdi:
1498 bdi_put(disk->bdi);
1499out_free_bioset:
1500 bioset_exit(&disk->bio_split);
1501out_free_disk:
1502 kfree(disk);
1503 return NULL;
1504}
1505
1506struct gendisk *__blk_alloc_disk(struct queue_limits *lim, int node,
1507 struct lock_class_key *lkclass)
1508{
1509 struct queue_limits default_lim = { };
1510 struct request_queue *q;
1511 struct gendisk *disk;
1512
1513 q = blk_alloc_queue(lim ? lim : &default_lim, node);
1514 if (IS_ERR(q))
1515 return ERR_CAST(q);
1516
1517 disk = __alloc_disk_node(q, node, lkclass);
1518 if (!disk) {
1519 blk_put_queue(q);
1520 return ERR_PTR(-ENOMEM);
1521 }
1522 set_bit(GD_OWNS_QUEUE, &disk->state);
1523 return disk;
1524}
1525EXPORT_SYMBOL(__blk_alloc_disk);
1526
1527/**
1528 * put_disk - decrements the gendisk refcount
1529 * @disk: the struct gendisk to decrement the refcount for
1530 *
1531 * This decrements the refcount for the struct gendisk. When this reaches 0
1532 * we'll have disk_release() called.
1533 *
1534 * Note: for blk-mq disk put_disk must be called before freeing the tag_set
1535 * when handling probe errors (that is before add_disk() is called).
1536 *
1537 * Context: Any context, but the last reference must not be dropped from
1538 * atomic context.
1539 */
1540void put_disk(struct gendisk *disk)
1541{
1542 if (disk)
1543 put_device(disk_to_dev(disk));
1544}
1545EXPORT_SYMBOL(put_disk);
1546
1547static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1548{
1549 char event[] = "DISK_RO=1";
1550 char *envp[] = { event, NULL };
1551
1552 if (!ro)
1553 event[8] = '0';
1554 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1555}
1556
1557/**
1558 * set_disk_ro - set a gendisk read-only
1559 * @disk: gendisk to operate on
1560 * @read_only: %true to set the disk read-only, %false set the disk read/write
1561 *
1562 * This function is used to indicate whether a given disk device should have its
1563 * read-only flag set. set_disk_ro() is typically used by device drivers to
1564 * indicate whether the underlying physical device is write-protected.
1565 */
1566void set_disk_ro(struct gendisk *disk, bool read_only)
1567{
1568 if (read_only) {
1569 if (test_and_set_bit(GD_READ_ONLY, &disk->state))
1570 return;
1571 } else {
1572 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
1573 return;
1574 }
1575 set_disk_ro_uevent(disk, read_only);
1576}
1577EXPORT_SYMBOL(set_disk_ro);
1578
1579void inc_diskseq(struct gendisk *disk)
1580{
1581 disk->diskseq = atomic64_inc_return(&diskseq);
1582}
Linux 6.x block layer and io_uring tree(s)