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 "blk-throttle.h"
29
30 #include "blk.h"
31 #include "blk-mq-sched.h"
32 #include "blk-rq-qos.h"
33 #include "blk-cgroup.h"
34
35 static struct kobject *block_depr;
36
37 /*
38 * Unique, monotonically increasing sequential number associated with block
39 * devices instances (i.e. incremented each time a device is attached).
40 * Associating uevents with block devices in userspace is difficult and racy:
41 * the uevent netlink socket is lossy, and on slow and overloaded systems has
42 * a very high latency.
43 * Block devices do not have exclusive owners in userspace, any process can set
44 * one up (e.g. loop devices). Moreover, device names can be reused (e.g. loop0
45 * can be reused again and again).
46 * A userspace process setting up a block device and watching for its events
47 * cannot thus reliably tell whether an event relates to the device it just set
48 * up or another earlier instance with the same name.
49 * This sequential number allows userspace processes to solve this problem, and
50 * uniquely associate an uevent to the lifetime to a device.
51 */
52 static atomic64_t diskseq;
53
54 /* for extended dynamic devt allocation, currently only one major is used */
55 #define NR_EXT_DEVT (1 << MINORBITS)
56 static DEFINE_IDA(ext_devt_ida);
57
set_capacity(struct gendisk * disk,sector_t sectors)58 void set_capacity(struct gendisk *disk, sector_t sectors)
59 {
60 struct block_device *bdev = disk->part0;
61
62 spin_lock(&bdev->bd_size_lock);
63 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
64 bdev->bd_nr_sectors = sectors;
65 spin_unlock(&bdev->bd_size_lock);
66 }
67 EXPORT_SYMBOL(set_capacity);
68
69 /*
70 * Set disk capacity and notify if the size is not currently zero and will not
71 * be set to zero. Returns true if a uevent was sent, otherwise false.
72 */
set_capacity_and_notify(struct gendisk * disk,sector_t size)73 bool set_capacity_and_notify(struct gendisk *disk, sector_t size)
74 {
75 sector_t capacity = get_capacity(disk);
76 char *envp[] = { "RESIZE=1", NULL };
77
78 set_capacity(disk, size);
79
80 /*
81 * Only print a message and send a uevent if the gendisk is user visible
82 * and alive. This avoids spamming the log and udev when setting the
83 * initial capacity during probing.
84 */
85 if (size == capacity ||
86 !disk_live(disk) ||
87 (disk->flags & GENHD_FL_HIDDEN))
88 return false;
89
90 pr_info("%s: detected capacity change from %lld to %lld\n",
91 disk->disk_name, capacity, size);
92
93 /*
94 * Historically we did not send a uevent for changes to/from an empty
95 * device.
96 */
97 if (!capacity || !size)
98 return false;
99 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
100 return true;
101 }
102 EXPORT_SYMBOL_GPL(set_capacity_and_notify);
103
part_stat_read_all(struct block_device * part,struct disk_stats * stat)104 static void part_stat_read_all(struct block_device *part,
105 struct disk_stats *stat)
106 {
107 int cpu;
108
109 memset(stat, 0, sizeof(struct disk_stats));
110 for_each_possible_cpu(cpu) {
111 struct disk_stats *ptr = per_cpu_ptr(part->bd_stats, cpu);
112 int group;
113
114 for (group = 0; group < NR_STAT_GROUPS; group++) {
115 stat->nsecs[group] += ptr->nsecs[group];
116 stat->sectors[group] += ptr->sectors[group];
117 stat->ios[group] += ptr->ios[group];
118 stat->merges[group] += ptr->merges[group];
119 }
120
121 stat->io_ticks += ptr->io_ticks;
122 }
123 }
124
part_in_flight(struct block_device * part)125 static unsigned int part_in_flight(struct block_device *part)
126 {
127 unsigned int inflight = 0;
128 int cpu;
129
130 for_each_possible_cpu(cpu) {
131 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
132 part_stat_local_read_cpu(part, in_flight[1], cpu);
133 }
134 if ((int)inflight < 0)
135 inflight = 0;
136
137 return inflight;
138 }
139
part_in_flight_rw(struct block_device * part,unsigned int inflight[2])140 static void part_in_flight_rw(struct block_device *part,
141 unsigned int inflight[2])
142 {
143 int cpu;
144
145 inflight[0] = 0;
146 inflight[1] = 0;
147 for_each_possible_cpu(cpu) {
148 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
149 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
150 }
151 if ((int)inflight[0] < 0)
152 inflight[0] = 0;
153 if ((int)inflight[1] < 0)
154 inflight[1] = 0;
155 }
156
157 /*
158 * Can be deleted altogether. Later.
159 *
160 */
161 #define BLKDEV_MAJOR_HASH_SIZE 255
162 static struct blk_major_name {
163 struct blk_major_name *next;
164 int major;
165 char name[16];
166 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
167 void (*probe)(dev_t devt);
168 #endif
169 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
170 static DEFINE_MUTEX(major_names_lock);
171 static DEFINE_SPINLOCK(major_names_spinlock);
172
173 /* index in the above - for now: assume no multimajor ranges */
major_to_index(unsigned major)174 static inline int major_to_index(unsigned major)
175 {
176 return major % BLKDEV_MAJOR_HASH_SIZE;
177 }
178
179 #ifdef CONFIG_PROC_FS
blkdev_show(struct seq_file * seqf,off_t offset)180 void blkdev_show(struct seq_file *seqf, off_t offset)
181 {
182 struct blk_major_name *dp;
183
184 spin_lock(&major_names_spinlock);
185 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
186 if (dp->major == offset)
187 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
188 spin_unlock(&major_names_spinlock);
189 }
190 #endif /* CONFIG_PROC_FS */
191
192 /**
193 * __register_blkdev - register a new block device
194 *
195 * @major: the requested major device number [1..BLKDEV_MAJOR_MAX-1]. If
196 * @major = 0, try to allocate any unused major number.
197 * @name: the name of the new block device as a zero terminated string
198 * @probe: pre-devtmpfs / pre-udev callback used to create disks when their
199 * pre-created device node is accessed. When a probe call uses
200 * add_disk() and it fails the driver must cleanup resources. This
201 * interface may soon be removed.
202 *
203 * The @name must be unique within the system.
204 *
205 * The return value depends on the @major input parameter:
206 *
207 * - if a major device number was requested in range [1..BLKDEV_MAJOR_MAX-1]
208 * then the function returns zero on success, or a negative error code
209 * - if any unused major number was requested with @major = 0 parameter
210 * then the return value is the allocated major number in range
211 * [1..BLKDEV_MAJOR_MAX-1] or a negative error code otherwise
212 *
213 * See Documentation/admin-guide/devices.txt for the list of allocated
214 * major numbers.
215 *
216 * Use register_blkdev instead for any new code.
217 */
__register_blkdev(unsigned int major,const char * name,void (* probe)(dev_t devt))218 int __register_blkdev(unsigned int major, const char *name,
219 void (*probe)(dev_t devt))
220 {
221 struct blk_major_name **n, *p;
222 int index, ret = 0;
223
224 mutex_lock(&major_names_lock);
225
226 /* temporary */
227 if (major == 0) {
228 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
229 if (major_names[index] == NULL)
230 break;
231 }
232
233 if (index == 0) {
234 printk("%s: failed to get major for %s\n",
235 __func__, name);
236 ret = -EBUSY;
237 goto out;
238 }
239 major = index;
240 ret = major;
241 }
242
243 if (major >= BLKDEV_MAJOR_MAX) {
244 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
245 __func__, major, BLKDEV_MAJOR_MAX-1, name);
246
247 ret = -EINVAL;
248 goto out;
249 }
250
251 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
252 if (p == NULL) {
253 ret = -ENOMEM;
254 goto out;
255 }
256
257 p->major = major;
258 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
259 p->probe = probe;
260 #endif
261 strlcpy(p->name, name, sizeof(p->name));
262 p->next = NULL;
263 index = major_to_index(major);
264
265 spin_lock(&major_names_spinlock);
266 for (n = &major_names[index]; *n; n = &(*n)->next) {
267 if ((*n)->major == major)
268 break;
269 }
270 if (!*n)
271 *n = p;
272 else
273 ret = -EBUSY;
274 spin_unlock(&major_names_spinlock);
275
276 if (ret < 0) {
277 printk("register_blkdev: cannot get major %u for %s\n",
278 major, name);
279 kfree(p);
280 }
281 out:
282 mutex_unlock(&major_names_lock);
283 return ret;
284 }
285 EXPORT_SYMBOL(__register_blkdev);
286
unregister_blkdev(unsigned int major,const char * name)287 void unregister_blkdev(unsigned int major, const char *name)
288 {
289 struct blk_major_name **n;
290 struct blk_major_name *p = NULL;
291 int index = major_to_index(major);
292
293 mutex_lock(&major_names_lock);
294 spin_lock(&major_names_spinlock);
295 for (n = &major_names[index]; *n; n = &(*n)->next)
296 if ((*n)->major == major)
297 break;
298 if (!*n || strcmp((*n)->name, name)) {
299 WARN_ON(1);
300 } else {
301 p = *n;
302 *n = p->next;
303 }
304 spin_unlock(&major_names_spinlock);
305 mutex_unlock(&major_names_lock);
306 kfree(p);
307 }
308
309 EXPORT_SYMBOL(unregister_blkdev);
310
blk_alloc_ext_minor(void)311 int blk_alloc_ext_minor(void)
312 {
313 int idx;
314
315 idx = ida_alloc_range(&ext_devt_ida, 0, NR_EXT_DEVT - 1, GFP_KERNEL);
316 if (idx == -ENOSPC)
317 return -EBUSY;
318 return idx;
319 }
320
blk_free_ext_minor(unsigned int minor)321 void blk_free_ext_minor(unsigned int minor)
322 {
323 ida_free(&ext_devt_ida, minor);
324 }
325
bdevt_str(dev_t devt,char * buf)326 static char *bdevt_str(dev_t devt, char *buf)
327 {
328 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
329 char tbuf[BDEVT_SIZE];
330 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
331 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
332 } else
333 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
334
335 return buf;
336 }
337
disk_uevent(struct gendisk * disk,enum kobject_action action)338 void disk_uevent(struct gendisk *disk, enum kobject_action action)
339 {
340 struct block_device *part;
341 unsigned long idx;
342
343 rcu_read_lock();
344 xa_for_each(&disk->part_tbl, idx, part) {
345 if (bdev_is_partition(part) && !bdev_nr_sectors(part))
346 continue;
347 if (!kobject_get_unless_zero(&part->bd_device.kobj))
348 continue;
349
350 rcu_read_unlock();
351 kobject_uevent(bdev_kobj(part), action);
352 put_device(&part->bd_device);
353 rcu_read_lock();
354 }
355 rcu_read_unlock();
356 }
357 EXPORT_SYMBOL_GPL(disk_uevent);
358
disk_scan_partitions(struct gendisk * disk,fmode_t mode,void * owner)359 int disk_scan_partitions(struct gendisk *disk, fmode_t mode, void *owner)
360 {
361 struct block_device *bdev;
362
363 if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN))
364 return -EINVAL;
365 if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state))
366 return -EINVAL;
367 if (disk->open_partitions)
368 return -EBUSY;
369 /* Someone else has bdev exclusively open? */
370 if (disk->part0->bd_holder && disk->part0->bd_holder != owner)
371 return -EBUSY;
372
373 set_bit(GD_NEED_PART_SCAN, &disk->state);
374 bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL);
375 if (IS_ERR(bdev))
376 return PTR_ERR(bdev);
377 blkdev_put(bdev, mode);
378 return 0;
379 }
380
381 /**
382 * device_add_disk - add disk information to kernel list
383 * @parent: parent device for the disk
384 * @disk: per-device partitioning information
385 * @groups: Additional per-device sysfs groups
386 *
387 * This function registers the partitioning information in @disk
388 * with the kernel.
389 */
device_add_disk(struct device * parent,struct gendisk * disk,const struct attribute_group ** groups)390 int __must_check device_add_disk(struct device *parent, struct gendisk *disk,
391 const struct attribute_group **groups)
392
393 {
394 struct device *ddev = disk_to_dev(disk);
395 int ret;
396
397 /* Only makes sense for bio-based to set ->poll_bio */
398 if (queue_is_mq(disk->queue) && disk->fops->poll_bio)
399 return -EINVAL;
400
401 /*
402 * The disk queue should now be all set with enough information about
403 * the device for the elevator code to pick an adequate default
404 * elevator if one is needed, that is, for devices requesting queue
405 * registration.
406 */
407 elevator_init_mq(disk->queue);
408
409 /*
410 * If the driver provides an explicit major number it also must provide
411 * the number of minors numbers supported, and those will be used to
412 * setup the gendisk.
413 * Otherwise just allocate the device numbers for both the whole device
414 * and all partitions from the extended dev_t space.
415 */
416 ret = -EINVAL;
417 if (disk->major) {
418 if (WARN_ON(!disk->minors))
419 goto out_exit_elevator;
420
421 if (disk->minors > DISK_MAX_PARTS) {
422 pr_err("block: can't allocate more than %d partitions\n",
423 DISK_MAX_PARTS);
424 disk->minors = DISK_MAX_PARTS;
425 }
426 if (disk->first_minor + disk->minors > MINORMASK + 1)
427 goto out_exit_elevator;
428 } else {
429 if (WARN_ON(disk->minors))
430 goto out_exit_elevator;
431
432 ret = blk_alloc_ext_minor();
433 if (ret < 0)
434 goto out_exit_elevator;
435 disk->major = BLOCK_EXT_MAJOR;
436 disk->first_minor = ret;
437 }
438
439 /* delay uevents, until we scanned partition table */
440 dev_set_uevent_suppress(ddev, 1);
441
442 ddev->parent = parent;
443 ddev->groups = groups;
444 dev_set_name(ddev, "%s", disk->disk_name);
445 if (!(disk->flags & GENHD_FL_HIDDEN))
446 ddev->devt = MKDEV(disk->major, disk->first_minor);
447 ret = device_add(ddev);
448 if (ret)
449 goto out_free_ext_minor;
450
451 ret = disk_alloc_events(disk);
452 if (ret)
453 goto out_device_del;
454
455 if (!sysfs_deprecated) {
456 ret = sysfs_create_link(block_depr, &ddev->kobj,
457 kobject_name(&ddev->kobj));
458 if (ret)
459 goto out_device_del;
460 }
461
462 /*
463 * avoid probable deadlock caused by allocating memory with
464 * GFP_KERNEL in runtime_resume callback of its all ancestor
465 * devices
466 */
467 pm_runtime_set_memalloc_noio(ddev, true);
468
469 ret = blk_integrity_add(disk);
470 if (ret)
471 goto out_del_block_link;
472
473 disk->part0->bd_holder_dir =
474 kobject_create_and_add("holders", &ddev->kobj);
475 if (!disk->part0->bd_holder_dir) {
476 ret = -ENOMEM;
477 goto out_del_integrity;
478 }
479 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
480 if (!disk->slave_dir) {
481 ret = -ENOMEM;
482 goto out_put_holder_dir;
483 }
484
485 ret = bd_register_pending_holders(disk);
486 if (ret < 0)
487 goto out_put_slave_dir;
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 bdev_add(disk->part0, ddev->devt);
505 if (get_capacity(disk))
506 disk_scan_partitions(disk, FMODE_READ, NULL);
507
508 /*
509 * Announce the disk and partitions after all partitions are
510 * created. (for hidden disks uevents remain suppressed forever)
511 */
512 dev_set_uevent_suppress(ddev, 0);
513 disk_uevent(disk, KOBJ_ADD);
514 } else {
515 /*
516 * Even if the block_device for a hidden gendisk is not
517 * registered, it needs to have a valid bd_dev so that the
518 * freeing of the dynamic major works.
519 */
520 disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor);
521 }
522
523 disk_update_readahead(disk);
524 disk_add_events(disk);
525 set_bit(GD_ADDED, &disk->state);
526 return 0;
527
528 out_unregister_bdi:
529 if (!(disk->flags & GENHD_FL_HIDDEN))
530 bdi_unregister(disk->bdi);
531 out_unregister_queue:
532 blk_unregister_queue(disk);
533 rq_qos_exit(disk->queue);
534 out_put_slave_dir:
535 kobject_put(disk->slave_dir);
536 disk->slave_dir = NULL;
537 out_put_holder_dir:
538 kobject_put(disk->part0->bd_holder_dir);
539 out_del_integrity:
540 blk_integrity_del(disk);
541 out_del_block_link:
542 if (!sysfs_deprecated)
543 sysfs_remove_link(block_depr, dev_name(ddev));
544 out_device_del:
545 device_del(ddev);
546 out_free_ext_minor:
547 if (disk->major == BLOCK_EXT_MAJOR)
548 blk_free_ext_minor(disk->first_minor);
549 out_exit_elevator:
550 if (disk->queue->elevator)
551 elevator_exit(disk->queue);
552 return ret;
553 }
554 EXPORT_SYMBOL(device_add_disk);
555
556 /**
557 * blk_mark_disk_dead - mark a disk as dead
558 * @disk: disk to mark as dead
559 *
560 * Mark as disk as dead (e.g. surprise removed) and don't accept any new I/O
561 * to this disk.
562 */
blk_mark_disk_dead(struct gendisk * disk)563 void blk_mark_disk_dead(struct gendisk *disk)
564 {
565 set_bit(GD_DEAD, &disk->state);
566 blk_queue_start_drain(disk->queue);
567 }
568 EXPORT_SYMBOL_GPL(blk_mark_disk_dead);
569
570 /**
571 * del_gendisk - remove the gendisk
572 * @disk: the struct gendisk to remove
573 *
574 * Removes the gendisk and all its associated resources. This deletes the
575 * partitions associated with the gendisk, and unregisters the associated
576 * request_queue.
577 *
578 * This is the counter to the respective __device_add_disk() call.
579 *
580 * The final removal of the struct gendisk happens when its refcount reaches 0
581 * with put_disk(), which should be called after del_gendisk(), if
582 * __device_add_disk() was used.
583 *
584 * Drivers exist which depend on the release of the gendisk to be synchronous,
585 * it should not be deferred.
586 *
587 * Context: can sleep
588 */
del_gendisk(struct gendisk * disk)589 void del_gendisk(struct gendisk *disk)
590 {
591 struct request_queue *q = disk->queue;
592
593 might_sleep();
594
595 if (WARN_ON_ONCE(!disk_live(disk) && !(disk->flags & GENHD_FL_HIDDEN)))
596 return;
597
598 blk_integrity_del(disk);
599 disk_del_events(disk);
600
601 mutex_lock(&disk->open_mutex);
602 remove_inode_hash(disk->part0->bd_inode);
603 blk_drop_partitions(disk);
604 mutex_unlock(&disk->open_mutex);
605
606 fsync_bdev(disk->part0);
607 __invalidate_device(disk->part0, true);
608
609 /*
610 * Fail any new I/O.
611 */
612 set_bit(GD_DEAD, &disk->state);
613 if (test_bit(GD_OWNS_QUEUE, &disk->state))
614 blk_queue_flag_set(QUEUE_FLAG_DYING, q);
615 set_capacity(disk, 0);
616
617 /*
618 * Prevent new I/O from crossing bio_queue_enter().
619 */
620 blk_queue_start_drain(q);
621
622 if (!(disk->flags & GENHD_FL_HIDDEN)) {
623 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
624
625 /*
626 * Unregister bdi before releasing device numbers (as they can
627 * get reused and we'd get clashes in sysfs).
628 */
629 bdi_unregister(disk->bdi);
630 }
631
632 blk_unregister_queue(disk);
633
634 kobject_put(disk->part0->bd_holder_dir);
635 kobject_put(disk->slave_dir);
636 disk->slave_dir = NULL;
637
638 part_stat_set_all(disk->part0, 0);
639 disk->part0->bd_stamp = 0;
640 if (!sysfs_deprecated)
641 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
642 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
643 device_del(disk_to_dev(disk));
644
645 blk_mq_freeze_queue_wait(q);
646
647 blk_throtl_cancel_bios(disk);
648
649 blk_sync_queue(q);
650 blk_flush_integrity();
651 blk_mq_cancel_work_sync(q);
652
653 blk_mq_quiesce_queue(q);
654 if (q->elevator) {
655 mutex_lock(&q->sysfs_lock);
656 elevator_exit(q);
657 mutex_unlock(&q->sysfs_lock);
658 }
659 rq_qos_exit(q);
660 blk_mq_unquiesce_queue(q);
661
662 /*
663 * If the disk does not own the queue, allow using passthrough requests
664 * again. Else leave the queue frozen to fail all I/O.
665 */
666 if (!test_bit(GD_OWNS_QUEUE, &disk->state)) {
667 blk_queue_flag_clear(QUEUE_FLAG_INIT_DONE, q);
668 __blk_mq_unfreeze_queue(q, true);
669 } else {
670 if (queue_is_mq(q))
671 blk_mq_exit_queue(q);
672 }
673 }
674 EXPORT_SYMBOL(del_gendisk);
675
676 /**
677 * invalidate_disk - invalidate the disk
678 * @disk: the struct gendisk to invalidate
679 *
680 * A helper to invalidates the disk. It will clean the disk's associated
681 * buffer/page caches and reset its internal states so that the disk
682 * can be reused by the drivers.
683 *
684 * Context: can sleep
685 */
invalidate_disk(struct gendisk * disk)686 void invalidate_disk(struct gendisk *disk)
687 {
688 struct block_device *bdev = disk->part0;
689
690 invalidate_bdev(bdev);
691 bdev->bd_inode->i_mapping->wb_err = 0;
692 set_capacity(disk, 0);
693 }
694 EXPORT_SYMBOL(invalidate_disk);
695
696 /* sysfs access to bad-blocks list. */
disk_badblocks_show(struct device * dev,struct device_attribute * attr,char * page)697 static ssize_t disk_badblocks_show(struct device *dev,
698 struct device_attribute *attr,
699 char *page)
700 {
701 struct gendisk *disk = dev_to_disk(dev);
702
703 if (!disk->bb)
704 return sprintf(page, "\n");
705
706 return badblocks_show(disk->bb, page, 0);
707 }
708
disk_badblocks_store(struct device * dev,struct device_attribute * attr,const char * page,size_t len)709 static ssize_t disk_badblocks_store(struct device *dev,
710 struct device_attribute *attr,
711 const char *page, size_t len)
712 {
713 struct gendisk *disk = dev_to_disk(dev);
714
715 if (!disk->bb)
716 return -ENXIO;
717
718 return badblocks_store(disk->bb, page, len, 0);
719 }
720
721 #ifdef CONFIG_BLOCK_LEGACY_AUTOLOAD
blk_request_module(dev_t devt)722 void blk_request_module(dev_t devt)
723 {
724 unsigned int major = MAJOR(devt);
725 struct blk_major_name **n;
726
727 mutex_lock(&major_names_lock);
728 for (n = &major_names[major_to_index(major)]; *n; n = &(*n)->next) {
729 if ((*n)->major == major && (*n)->probe) {
730 (*n)->probe(devt);
731 mutex_unlock(&major_names_lock);
732 return;
733 }
734 }
735 mutex_unlock(&major_names_lock);
736
737 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
738 /* Make old-style 2.4 aliases work */
739 request_module("block-major-%d", MAJOR(devt));
740 }
741 #endif /* CONFIG_BLOCK_LEGACY_AUTOLOAD */
742
743 /*
744 * print a full list of all partitions - intended for places where the root
745 * filesystem can't be mounted and thus to give the victim some idea of what
746 * went wrong
747 */
printk_all_partitions(void)748 void __init printk_all_partitions(void)
749 {
750 struct class_dev_iter iter;
751 struct device *dev;
752
753 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
754 while ((dev = class_dev_iter_next(&iter))) {
755 struct gendisk *disk = dev_to_disk(dev);
756 struct block_device *part;
757 char devt_buf[BDEVT_SIZE];
758 unsigned long idx;
759
760 /*
761 * Don't show empty devices or things that have been
762 * suppressed
763 */
764 if (get_capacity(disk) == 0 || (disk->flags & GENHD_FL_HIDDEN))
765 continue;
766
767 /*
768 * Note, unlike /proc/partitions, I am showing the numbers in
769 * hex - the same format as the root= option takes.
770 */
771 rcu_read_lock();
772 xa_for_each(&disk->part_tbl, idx, part) {
773 if (!bdev_nr_sectors(part))
774 continue;
775 printk("%s%s %10llu %pg %s",
776 bdev_is_partition(part) ? " " : "",
777 bdevt_str(part->bd_dev, devt_buf),
778 bdev_nr_sectors(part) >> 1, part,
779 part->bd_meta_info ?
780 part->bd_meta_info->uuid : "");
781 if (bdev_is_partition(part))
782 printk("\n");
783 else if (dev->parent && dev->parent->driver)
784 printk(" driver: %s\n",
785 dev->parent->driver->name);
786 else
787 printk(" (driver?)\n");
788 }
789 rcu_read_unlock();
790 }
791 class_dev_iter_exit(&iter);
792 }
793
794 #ifdef CONFIG_PROC_FS
795 /* iterator */
disk_seqf_start(struct seq_file * seqf,loff_t * pos)796 static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
797 {
798 loff_t skip = *pos;
799 struct class_dev_iter *iter;
800 struct device *dev;
801
802 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
803 if (!iter)
804 return ERR_PTR(-ENOMEM);
805
806 seqf->private = iter;
807 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
808 do {
809 dev = class_dev_iter_next(iter);
810 if (!dev)
811 return NULL;
812 } while (skip--);
813
814 return dev_to_disk(dev);
815 }
816
disk_seqf_next(struct seq_file * seqf,void * v,loff_t * pos)817 static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
818 {
819 struct device *dev;
820
821 (*pos)++;
822 dev = class_dev_iter_next(seqf->private);
823 if (dev)
824 return dev_to_disk(dev);
825
826 return NULL;
827 }
828
disk_seqf_stop(struct seq_file * seqf,void * v)829 static void disk_seqf_stop(struct seq_file *seqf, void *v)
830 {
831 struct class_dev_iter *iter = seqf->private;
832
833 /* stop is called even after start failed :-( */
834 if (iter) {
835 class_dev_iter_exit(iter);
836 kfree(iter);
837 seqf->private = NULL;
838 }
839 }
840
show_partition_start(struct seq_file * seqf,loff_t * pos)841 static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
842 {
843 void *p;
844
845 p = disk_seqf_start(seqf, pos);
846 if (!IS_ERR_OR_NULL(p) && !*pos)
847 seq_puts(seqf, "major minor #blocks name\n\n");
848 return p;
849 }
850
show_partition(struct seq_file * seqf,void * v)851 static int show_partition(struct seq_file *seqf, void *v)
852 {
853 struct gendisk *sgp = v;
854 struct block_device *part;
855 unsigned long idx;
856
857 if (!get_capacity(sgp) || (sgp->flags & GENHD_FL_HIDDEN))
858 return 0;
859
860 rcu_read_lock();
861 xa_for_each(&sgp->part_tbl, idx, part) {
862 if (!bdev_nr_sectors(part))
863 continue;
864 seq_printf(seqf, "%4d %7d %10llu %pg\n",
865 MAJOR(part->bd_dev), MINOR(part->bd_dev),
866 bdev_nr_sectors(part) >> 1, part);
867 }
868 rcu_read_unlock();
869 return 0;
870 }
871
872 static const struct seq_operations partitions_op = {
873 .start = show_partition_start,
874 .next = disk_seqf_next,
875 .stop = disk_seqf_stop,
876 .show = show_partition
877 };
878 #endif
879
genhd_device_init(void)880 static int __init genhd_device_init(void)
881 {
882 int error;
883
884 block_class.dev_kobj = sysfs_dev_block_kobj;
885 error = class_register(&block_class);
886 if (unlikely(error))
887 return error;
888 blk_dev_init();
889
890 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
891
892 /* create top-level block dir */
893 if (!sysfs_deprecated)
894 block_depr = kobject_create_and_add("block", NULL);
895 return 0;
896 }
897
898 subsys_initcall(genhd_device_init);
899
disk_range_show(struct device * dev,struct device_attribute * attr,char * buf)900 static ssize_t disk_range_show(struct device *dev,
901 struct device_attribute *attr, char *buf)
902 {
903 struct gendisk *disk = dev_to_disk(dev);
904
905 return sprintf(buf, "%d\n", disk->minors);
906 }
907
disk_ext_range_show(struct device * dev,struct device_attribute * attr,char * buf)908 static ssize_t disk_ext_range_show(struct device *dev,
909 struct device_attribute *attr, char *buf)
910 {
911 struct gendisk *disk = dev_to_disk(dev);
912
913 return sprintf(buf, "%d\n",
914 (disk->flags & GENHD_FL_NO_PART) ? 1 : DISK_MAX_PARTS);
915 }
916
disk_removable_show(struct device * dev,struct device_attribute * attr,char * buf)917 static ssize_t disk_removable_show(struct device *dev,
918 struct device_attribute *attr, char *buf)
919 {
920 struct gendisk *disk = dev_to_disk(dev);
921
922 return sprintf(buf, "%d\n",
923 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
924 }
925
disk_hidden_show(struct device * dev,struct device_attribute * attr,char * buf)926 static ssize_t disk_hidden_show(struct device *dev,
927 struct device_attribute *attr, char *buf)
928 {
929 struct gendisk *disk = dev_to_disk(dev);
930
931 return sprintf(buf, "%d\n",
932 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
933 }
934
disk_ro_show(struct device * dev,struct device_attribute * attr,char * buf)935 static ssize_t disk_ro_show(struct device *dev,
936 struct device_attribute *attr, char *buf)
937 {
938 struct gendisk *disk = dev_to_disk(dev);
939
940 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
941 }
942
part_size_show(struct device * dev,struct device_attribute * attr,char * buf)943 ssize_t part_size_show(struct device *dev,
944 struct device_attribute *attr, char *buf)
945 {
946 return sprintf(buf, "%llu\n", bdev_nr_sectors(dev_to_bdev(dev)));
947 }
948
part_stat_show(struct device * dev,struct device_attribute * attr,char * buf)949 ssize_t part_stat_show(struct device *dev,
950 struct device_attribute *attr, char *buf)
951 {
952 struct block_device *bdev = dev_to_bdev(dev);
953 struct request_queue *q = bdev_get_queue(bdev);
954 struct disk_stats stat;
955 unsigned int inflight;
956
957 if (queue_is_mq(q))
958 inflight = blk_mq_in_flight(q, bdev);
959 else
960 inflight = part_in_flight(bdev);
961
962 if (inflight) {
963 part_stat_lock();
964 update_io_ticks(bdev, jiffies, true);
965 part_stat_unlock();
966 }
967 part_stat_read_all(bdev, &stat);
968 return sprintf(buf,
969 "%8lu %8lu %8llu %8u "
970 "%8lu %8lu %8llu %8u "
971 "%8u %8u %8u "
972 "%8lu %8lu %8llu %8u "
973 "%8lu %8u"
974 "\n",
975 stat.ios[STAT_READ],
976 stat.merges[STAT_READ],
977 (unsigned long long)stat.sectors[STAT_READ],
978 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
979 stat.ios[STAT_WRITE],
980 stat.merges[STAT_WRITE],
981 (unsigned long long)stat.sectors[STAT_WRITE],
982 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
983 inflight,
984 jiffies_to_msecs(stat.io_ticks),
985 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
986 stat.nsecs[STAT_WRITE] +
987 stat.nsecs[STAT_DISCARD] +
988 stat.nsecs[STAT_FLUSH],
989 NSEC_PER_MSEC),
990 stat.ios[STAT_DISCARD],
991 stat.merges[STAT_DISCARD],
992 (unsigned long long)stat.sectors[STAT_DISCARD],
993 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
994 stat.ios[STAT_FLUSH],
995 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
996 }
997
part_inflight_show(struct device * dev,struct device_attribute * attr,char * buf)998 ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
999 char *buf)
1000 {
1001 struct block_device *bdev = dev_to_bdev(dev);
1002 struct request_queue *q = bdev_get_queue(bdev);
1003 unsigned int inflight[2];
1004
1005 if (queue_is_mq(q))
1006 blk_mq_in_flight_rw(q, bdev, inflight);
1007 else
1008 part_in_flight_rw(bdev, inflight);
1009
1010 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
1011 }
1012
disk_capability_show(struct device * dev,struct device_attribute * attr,char * buf)1013 static ssize_t disk_capability_show(struct device *dev,
1014 struct device_attribute *attr, char *buf)
1015 {
1016 struct gendisk *disk = dev_to_disk(dev);
1017
1018 return sprintf(buf, "%x\n", disk->flags);
1019 }
1020
disk_alignment_offset_show(struct device * dev,struct device_attribute * attr,char * buf)1021 static ssize_t disk_alignment_offset_show(struct device *dev,
1022 struct device_attribute *attr,
1023 char *buf)
1024 {
1025 struct gendisk *disk = dev_to_disk(dev);
1026
1027 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0));
1028 }
1029
disk_discard_alignment_show(struct device * dev,struct device_attribute * attr,char * buf)1030 static ssize_t disk_discard_alignment_show(struct device *dev,
1031 struct device_attribute *attr,
1032 char *buf)
1033 {
1034 struct gendisk *disk = dev_to_disk(dev);
1035
1036 return sprintf(buf, "%d\n", bdev_alignment_offset(disk->part0));
1037 }
1038
diskseq_show(struct device * dev,struct device_attribute * attr,char * buf)1039 static ssize_t diskseq_show(struct device *dev,
1040 struct device_attribute *attr, char *buf)
1041 {
1042 struct gendisk *disk = dev_to_disk(dev);
1043
1044 return sprintf(buf, "%llu\n", disk->diskseq);
1045 }
1046
1047 static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1048 static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1049 static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1050 static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1051 static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1052 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1053 static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1054 static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1055 static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1056 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1057 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1058 static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1059 static DEVICE_ATTR(diskseq, 0444, diskseq_show, NULL);
1060
1061 #ifdef CONFIG_FAIL_MAKE_REQUEST
part_fail_show(struct device * dev,struct device_attribute * attr,char * buf)1062 ssize_t part_fail_show(struct device *dev,
1063 struct device_attribute *attr, char *buf)
1064 {
1065 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_make_it_fail);
1066 }
1067
part_fail_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)1068 ssize_t part_fail_store(struct device *dev,
1069 struct device_attribute *attr,
1070 const char *buf, size_t count)
1071 {
1072 int i;
1073
1074 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1075 dev_to_bdev(dev)->bd_make_it_fail = i;
1076
1077 return count;
1078 }
1079
1080 static struct device_attribute dev_attr_fail =
1081 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1082 #endif /* CONFIG_FAIL_MAKE_REQUEST */
1083
1084 #ifdef CONFIG_FAIL_IO_TIMEOUT
1085 static struct device_attribute dev_attr_fail_timeout =
1086 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1087 #endif
1088
1089 static struct attribute *disk_attrs[] = {
1090 &dev_attr_range.attr,
1091 &dev_attr_ext_range.attr,
1092 &dev_attr_removable.attr,
1093 &dev_attr_hidden.attr,
1094 &dev_attr_ro.attr,
1095 &dev_attr_size.attr,
1096 &dev_attr_alignment_offset.attr,
1097 &dev_attr_discard_alignment.attr,
1098 &dev_attr_capability.attr,
1099 &dev_attr_stat.attr,
1100 &dev_attr_inflight.attr,
1101 &dev_attr_badblocks.attr,
1102 &dev_attr_events.attr,
1103 &dev_attr_events_async.attr,
1104 &dev_attr_events_poll_msecs.attr,
1105 &dev_attr_diskseq.attr,
1106 #ifdef CONFIG_FAIL_MAKE_REQUEST
1107 &dev_attr_fail.attr,
1108 #endif
1109 #ifdef CONFIG_FAIL_IO_TIMEOUT
1110 &dev_attr_fail_timeout.attr,
1111 #endif
1112 NULL
1113 };
1114
disk_visible(struct kobject * kobj,struct attribute * a,int n)1115 static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1116 {
1117 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1118 struct gendisk *disk = dev_to_disk(dev);
1119
1120 if (a == &dev_attr_badblocks.attr && !disk->bb)
1121 return 0;
1122 return a->mode;
1123 }
1124
1125 static struct attribute_group disk_attr_group = {
1126 .attrs = disk_attrs,
1127 .is_visible = disk_visible,
1128 };
1129
1130 static const struct attribute_group *disk_attr_groups[] = {
1131 &disk_attr_group,
1132 #ifdef CONFIG_BLK_DEV_IO_TRACE
1133 &blk_trace_attr_group,
1134 #endif
1135 NULL
1136 };
1137
1138 /**
1139 * disk_release - releases all allocated resources of the gendisk
1140 * @dev: the device representing this disk
1141 *
1142 * This function releases all allocated resources of the gendisk.
1143 *
1144 * Drivers which used __device_add_disk() have a gendisk with a request_queue
1145 * assigned. Since the request_queue sits on top of the gendisk for these
1146 * drivers we also call blk_put_queue() for them, and we expect the
1147 * request_queue refcount to reach 0 at this point, and so the request_queue
1148 * will also be freed prior to the disk.
1149 *
1150 * Context: can sleep
1151 */
disk_release(struct device * dev)1152 static void disk_release(struct device *dev)
1153 {
1154 struct gendisk *disk = dev_to_disk(dev);
1155
1156 might_sleep();
1157 WARN_ON_ONCE(disk_live(disk));
1158
1159 /*
1160 * To undo the all initialization from blk_mq_init_allocated_queue in
1161 * case of a probe failure where add_disk is never called we have to
1162 * call blk_mq_exit_queue here. We can't do this for the more common
1163 * teardown case (yet) as the tagset can be gone by the time the disk
1164 * is released once it was added.
1165 */
1166 if (queue_is_mq(disk->queue) &&
1167 test_bit(GD_OWNS_QUEUE, &disk->state) &&
1168 !test_bit(GD_ADDED, &disk->state))
1169 blk_mq_exit_queue(disk->queue);
1170
1171 blkcg_exit_disk(disk);
1172
1173 bioset_exit(&disk->bio_split);
1174
1175 disk_release_events(disk);
1176 kfree(disk->random);
1177 disk_free_zone_bitmaps(disk);
1178 xa_destroy(&disk->part_tbl);
1179
1180 disk->queue->disk = NULL;
1181 blk_put_queue(disk->queue);
1182
1183 if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk)
1184 disk->fops->free_disk(disk);
1185
1186 iput(disk->part0->bd_inode); /* frees the disk */
1187 }
1188
block_uevent(struct device * dev,struct kobj_uevent_env * env)1189 static int block_uevent(struct device *dev, struct kobj_uevent_env *env)
1190 {
1191 struct gendisk *disk = dev_to_disk(dev);
1192
1193 return add_uevent_var(env, "DISKSEQ=%llu", disk->diskseq);
1194 }
1195
1196 struct class block_class = {
1197 .name = "block",
1198 .dev_uevent = block_uevent,
1199 };
1200
block_devnode(struct device * dev,umode_t * mode,kuid_t * uid,kgid_t * gid)1201 static char *block_devnode(struct device *dev, umode_t *mode,
1202 kuid_t *uid, kgid_t *gid)
1203 {
1204 struct gendisk *disk = dev_to_disk(dev);
1205
1206 if (disk->fops->devnode)
1207 return disk->fops->devnode(disk, mode);
1208 return NULL;
1209 }
1210
1211 const struct device_type disk_type = {
1212 .name = "disk",
1213 .groups = disk_attr_groups,
1214 .release = disk_release,
1215 .devnode = block_devnode,
1216 };
1217
1218 #ifdef CONFIG_PROC_FS
1219 /*
1220 * aggregate disk stat collector. Uses the same stats that the sysfs
1221 * entries do, above, but makes them available through one seq_file.
1222 *
1223 * The output looks suspiciously like /proc/partitions with a bunch of
1224 * extra fields.
1225 */
diskstats_show(struct seq_file * seqf,void * v)1226 static int diskstats_show(struct seq_file *seqf, void *v)
1227 {
1228 struct gendisk *gp = v;
1229 struct block_device *hd;
1230 unsigned int inflight;
1231 struct disk_stats stat;
1232 unsigned long idx;
1233
1234 /*
1235 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
1236 seq_puts(seqf, "major minor name"
1237 " rio rmerge rsect ruse wio wmerge "
1238 "wsect wuse running use aveq"
1239 "\n\n");
1240 */
1241
1242 rcu_read_lock();
1243 xa_for_each(&gp->part_tbl, idx, hd) {
1244 if (bdev_is_partition(hd) && !bdev_nr_sectors(hd))
1245 continue;
1246 if (queue_is_mq(gp->queue))
1247 inflight = blk_mq_in_flight(gp->queue, hd);
1248 else
1249 inflight = part_in_flight(hd);
1250
1251 if (inflight) {
1252 part_stat_lock();
1253 update_io_ticks(hd, jiffies, true);
1254 part_stat_unlock();
1255 }
1256 part_stat_read_all(hd, &stat);
1257 seq_printf(seqf, "%4d %7d %pg "
1258 "%lu %lu %lu %u "
1259 "%lu %lu %lu %u "
1260 "%u %u %u "
1261 "%lu %lu %lu %u "
1262 "%lu %u"
1263 "\n",
1264 MAJOR(hd->bd_dev), MINOR(hd->bd_dev), hd,
1265 stat.ios[STAT_READ],
1266 stat.merges[STAT_READ],
1267 stat.sectors[STAT_READ],
1268 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1269 NSEC_PER_MSEC),
1270 stat.ios[STAT_WRITE],
1271 stat.merges[STAT_WRITE],
1272 stat.sectors[STAT_WRITE],
1273 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1274 NSEC_PER_MSEC),
1275 inflight,
1276 jiffies_to_msecs(stat.io_ticks),
1277 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1278 stat.nsecs[STAT_WRITE] +
1279 stat.nsecs[STAT_DISCARD] +
1280 stat.nsecs[STAT_FLUSH],
1281 NSEC_PER_MSEC),
1282 stat.ios[STAT_DISCARD],
1283 stat.merges[STAT_DISCARD],
1284 stat.sectors[STAT_DISCARD],
1285 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1286 NSEC_PER_MSEC),
1287 stat.ios[STAT_FLUSH],
1288 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1289 NSEC_PER_MSEC)
1290 );
1291 }
1292 rcu_read_unlock();
1293
1294 return 0;
1295 }
1296
1297 static const struct seq_operations diskstats_op = {
1298 .start = disk_seqf_start,
1299 .next = disk_seqf_next,
1300 .stop = disk_seqf_stop,
1301 .show = diskstats_show
1302 };
1303
proc_genhd_init(void)1304 static int __init proc_genhd_init(void)
1305 {
1306 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1307 proc_create_seq("partitions", 0, NULL, &partitions_op);
1308 return 0;
1309 }
1310 module_init(proc_genhd_init);
1311 #endif /* CONFIG_PROC_FS */
1312
part_devt(struct gendisk * disk,u8 partno)1313 dev_t part_devt(struct gendisk *disk, u8 partno)
1314 {
1315 struct block_device *part;
1316 dev_t devt = 0;
1317
1318 rcu_read_lock();
1319 part = xa_load(&disk->part_tbl, partno);
1320 if (part)
1321 devt = part->bd_dev;
1322 rcu_read_unlock();
1323
1324 return devt;
1325 }
1326
blk_lookup_devt(const char * name,int partno)1327 dev_t blk_lookup_devt(const char *name, int partno)
1328 {
1329 dev_t devt = MKDEV(0, 0);
1330 struct class_dev_iter iter;
1331 struct device *dev;
1332
1333 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1334 while ((dev = class_dev_iter_next(&iter))) {
1335 struct gendisk *disk = dev_to_disk(dev);
1336
1337 if (strcmp(dev_name(dev), name))
1338 continue;
1339
1340 if (partno < disk->minors) {
1341 /* We need to return the right devno, even
1342 * if the partition doesn't exist yet.
1343 */
1344 devt = MKDEV(MAJOR(dev->devt),
1345 MINOR(dev->devt) + partno);
1346 } else {
1347 devt = part_devt(disk, partno);
1348 if (devt)
1349 break;
1350 }
1351 }
1352 class_dev_iter_exit(&iter);
1353 return devt;
1354 }
1355
__alloc_disk_node(struct request_queue * q,int node_id,struct lock_class_key * lkclass)1356 struct gendisk *__alloc_disk_node(struct request_queue *q, int node_id,
1357 struct lock_class_key *lkclass)
1358 {
1359 struct gendisk *disk;
1360
1361 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1362 if (!disk)
1363 return NULL;
1364
1365 if (bioset_init(&disk->bio_split, BIO_POOL_SIZE, 0, 0))
1366 goto out_free_disk;
1367
1368 disk->bdi = bdi_alloc(node_id);
1369 if (!disk->bdi)
1370 goto out_free_bioset;
1371
1372 /* bdev_alloc() might need the queue, set before the first call */
1373 disk->queue = q;
1374
1375 disk->part0 = bdev_alloc(disk, 0);
1376 if (!disk->part0)
1377 goto out_free_bdi;
1378
1379 disk->node_id = node_id;
1380 mutex_init(&disk->open_mutex);
1381 xa_init(&disk->part_tbl);
1382 if (xa_insert(&disk->part_tbl, 0, disk->part0, GFP_KERNEL))
1383 goto out_destroy_part_tbl;
1384
1385 if (blkcg_init_disk(disk))
1386 goto out_erase_part0;
1387
1388 rand_initialize_disk(disk);
1389 disk_to_dev(disk)->class = &block_class;
1390 disk_to_dev(disk)->type = &disk_type;
1391 device_initialize(disk_to_dev(disk));
1392 inc_diskseq(disk);
1393 q->disk = disk;
1394 lockdep_init_map(&disk->lockdep_map, "(bio completion)", lkclass, 0);
1395 #ifdef CONFIG_BLOCK_HOLDER_DEPRECATED
1396 INIT_LIST_HEAD(&disk->slave_bdevs);
1397 #endif
1398 return disk;
1399
1400 out_erase_part0:
1401 xa_erase(&disk->part_tbl, 0);
1402 out_destroy_part_tbl:
1403 xa_destroy(&disk->part_tbl);
1404 disk->part0->bd_disk = NULL;
1405 iput(disk->part0->bd_inode);
1406 out_free_bdi:
1407 bdi_put(disk->bdi);
1408 out_free_bioset:
1409 bioset_exit(&disk->bio_split);
1410 out_free_disk:
1411 kfree(disk);
1412 return NULL;
1413 }
1414
__blk_alloc_disk(int node,struct lock_class_key * lkclass)1415 struct gendisk *__blk_alloc_disk(int node, struct lock_class_key *lkclass)
1416 {
1417 struct request_queue *q;
1418 struct gendisk *disk;
1419
1420 q = blk_alloc_queue(node, false);
1421 if (!q)
1422 return NULL;
1423
1424 disk = __alloc_disk_node(q, node, lkclass);
1425 if (!disk) {
1426 blk_put_queue(q);
1427 return NULL;
1428 }
1429 set_bit(GD_OWNS_QUEUE, &disk->state);
1430 return disk;
1431 }
1432 EXPORT_SYMBOL(__blk_alloc_disk);
1433
1434 /**
1435 * put_disk - decrements the gendisk refcount
1436 * @disk: the struct gendisk to decrement the refcount for
1437 *
1438 * This decrements the refcount for the struct gendisk. When this reaches 0
1439 * we'll have disk_release() called.
1440 *
1441 * Note: for blk-mq disk put_disk must be called before freeing the tag_set
1442 * when handling probe errors (that is before add_disk() is called).
1443 *
1444 * Context: Any context, but the last reference must not be dropped from
1445 * atomic context.
1446 */
put_disk(struct gendisk * disk)1447 void put_disk(struct gendisk *disk)
1448 {
1449 if (disk)
1450 put_device(disk_to_dev(disk));
1451 }
1452 EXPORT_SYMBOL(put_disk);
1453
set_disk_ro_uevent(struct gendisk * gd,int ro)1454 static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1455 {
1456 char event[] = "DISK_RO=1";
1457 char *envp[] = { event, NULL };
1458
1459 if (!ro)
1460 event[8] = '0';
1461 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1462 }
1463
1464 /**
1465 * set_disk_ro - set a gendisk read-only
1466 * @disk: gendisk to operate on
1467 * @read_only: %true to set the disk read-only, %false set the disk read/write
1468 *
1469 * This function is used to indicate whether a given disk device should have its
1470 * read-only flag set. set_disk_ro() is typically used by device drivers to
1471 * indicate whether the underlying physical device is write-protected.
1472 */
set_disk_ro(struct gendisk * disk,bool read_only)1473 void set_disk_ro(struct gendisk *disk, bool read_only)
1474 {
1475 if (read_only) {
1476 if (test_and_set_bit(GD_READ_ONLY, &disk->state))
1477 return;
1478 } else {
1479 if (!test_and_clear_bit(GD_READ_ONLY, &disk->state))
1480 return;
1481 }
1482 set_disk_ro_uevent(disk, read_only);
1483 }
1484 EXPORT_SYMBOL(set_disk_ro);
1485
inc_diskseq(struct gendisk * disk)1486 void inc_diskseq(struct gendisk *disk)
1487 {
1488 disk->diskseq = atomic64_inc_return(&diskseq);
1489 }
1490