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