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CommitLineData
1da177e4
LT
1/*
2 * gendisk handling
3 */
4
1da177e4
LT
5#include <linux/module.h>
6#include <linux/fs.h>
7#include <linux/genhd.h>
b446b60e 8#include <linux/kdev_t.h>
1da177e4
LT
9#include <linux/kernel.h>
10#include <linux/blkdev.h>
11#include <linux/init.h>
12#include <linux/spinlock.h>
f500975a 13#include <linux/proc_fs.h>
1da177e4
LT
14#include <linux/seq_file.h>
15#include <linux/slab.h>
16#include <linux/kmod.h>
17#include <linux/kobj_map.h>
58383af6 18#include <linux/mutex.h>
bcce3de1 19#include <linux/idr.h>
77ea887e 20#include <linux/log2.h>
25e823c8 21#include <linux/pm_runtime.h>
1da177e4 22
ff88972c
AB
23#include "blk.h"
24
edfaa7c3 25static DEFINE_MUTEX(block_class_lock);
edfaa7c3 26struct kobject *block_depr;
1da177e4 27
bcce3de1 28/* for extended dynamic devt allocation, currently only one major is used */
ce23bba8 29#define NR_EXT_DEVT (1 << MINORBITS)
bcce3de1 30
2da78092 31/* For extended devt allocation. ext_devt_lock prevents look up
bcce3de1
TH
32 * results from going away underneath its user.
33 */
2da78092 34static DEFINE_SPINLOCK(ext_devt_lock);
bcce3de1
TH
35static DEFINE_IDR(ext_devt_idr);
36
1826eadf
AB
37static struct device_type disk_type;
38
12c2bdb2
DB
39static void disk_check_events(struct disk_events *ev,
40 unsigned int *clearing_ptr);
9f53d2fe 41static void disk_alloc_events(struct gendisk *disk);
77ea887e
TH
42static void disk_add_events(struct gendisk *disk);
43static void disk_del_events(struct gendisk *disk);
44static void disk_release_events(struct gendisk *disk);
45
e71bf0d0
TH
46/**
47 * disk_get_part - get partition
48 * @disk: disk to look partition from
49 * @partno: partition number
50 *
51 * Look for partition @partno from @disk. If found, increment
52 * reference count and return it.
53 *
54 * CONTEXT:
55 * Don't care.
56 *
57 * RETURNS:
58 * Pointer to the found partition on success, NULL if not found.
59 */
60struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
61{
540eed56
TH
62 struct hd_struct *part = NULL;
63 struct disk_part_tbl *ptbl;
e71bf0d0 64
540eed56 65 if (unlikely(partno < 0))
e71bf0d0 66 return NULL;
540eed56 67
e71bf0d0 68 rcu_read_lock();
540eed56
TH
69
70 ptbl = rcu_dereference(disk->part_tbl);
71 if (likely(partno < ptbl->len)) {
72 part = rcu_dereference(ptbl->part[partno]);
73 if (part)
74 get_device(part_to_dev(part));
75 }
76
e71bf0d0
TH
77 rcu_read_unlock();
78
79 return part;
80}
81EXPORT_SYMBOL_GPL(disk_get_part);
82
83/**
84 * disk_part_iter_init - initialize partition iterator
85 * @piter: iterator to initialize
86 * @disk: disk to iterate over
87 * @flags: DISK_PITER_* flags
88 *
89 * Initialize @piter so that it iterates over partitions of @disk.
90 *
91 * CONTEXT:
92 * Don't care.
93 */
94void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
95 unsigned int flags)
96{
540eed56
TH
97 struct disk_part_tbl *ptbl;
98
99 rcu_read_lock();
100 ptbl = rcu_dereference(disk->part_tbl);
101
e71bf0d0
TH
102 piter->disk = disk;
103 piter->part = NULL;
104
105 if (flags & DISK_PITER_REVERSE)
540eed56 106 piter->idx = ptbl->len - 1;
71982a40 107 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
e71bf0d0 108 piter->idx = 0;
b5d0b9df
TH
109 else
110 piter->idx = 1;
e71bf0d0
TH
111
112 piter->flags = flags;
540eed56
TH
113
114 rcu_read_unlock();
e71bf0d0
TH
115}
116EXPORT_SYMBOL_GPL(disk_part_iter_init);
117
118/**
119 * disk_part_iter_next - proceed iterator to the next partition and return it
120 * @piter: iterator of interest
121 *
122 * Proceed @piter to the next partition and return it.
123 *
124 * CONTEXT:
125 * Don't care.
126 */
127struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
128{
540eed56 129 struct disk_part_tbl *ptbl;
e71bf0d0
TH
130 int inc, end;
131
132 /* put the last partition */
133 disk_put_part(piter->part);
134 piter->part = NULL;
135
540eed56 136 /* get part_tbl */
e71bf0d0 137 rcu_read_lock();
540eed56 138 ptbl = rcu_dereference(piter->disk->part_tbl);
e71bf0d0
TH
139
140 /* determine iteration parameters */
141 if (piter->flags & DISK_PITER_REVERSE) {
142 inc = -1;
71982a40
TH
143 if (piter->flags & (DISK_PITER_INCL_PART0 |
144 DISK_PITER_INCL_EMPTY_PART0))
b5d0b9df
TH
145 end = -1;
146 else
147 end = 0;
e71bf0d0
TH
148 } else {
149 inc = 1;
540eed56 150 end = ptbl->len;
e71bf0d0
TH
151 }
152
153 /* iterate to the next partition */
154 for (; piter->idx != end; piter->idx += inc) {
155 struct hd_struct *part;
156
540eed56 157 part = rcu_dereference(ptbl->part[piter->idx]);
e71bf0d0
TH
158 if (!part)
159 continue;
c83f6bf9 160 if (!part_nr_sects_read(part) &&
71982a40
TH
161 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
162 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
163 piter->idx == 0))
e71bf0d0
TH
164 continue;
165
ed9e1982 166 get_device(part_to_dev(part));
e71bf0d0
TH
167 piter->part = part;
168 piter->idx += inc;
169 break;
170 }
171
172 rcu_read_unlock();
173
174 return piter->part;
175}
176EXPORT_SYMBOL_GPL(disk_part_iter_next);
177
178/**
179 * disk_part_iter_exit - finish up partition iteration
180 * @piter: iter of interest
181 *
182 * Called when iteration is over. Cleans up @piter.
183 *
184 * CONTEXT:
185 * Don't care.
186 */
187void disk_part_iter_exit(struct disk_part_iter *piter)
188{
189 disk_put_part(piter->part);
190 piter->part = NULL;
191}
192EXPORT_SYMBOL_GPL(disk_part_iter_exit);
193
a6f23657
JA
194static inline int sector_in_part(struct hd_struct *part, sector_t sector)
195{
196 return part->start_sect <= sector &&
c83f6bf9 197 sector < part->start_sect + part_nr_sects_read(part);
a6f23657
JA
198}
199
e71bf0d0
TH
200/**
201 * disk_map_sector_rcu - map sector to partition
202 * @disk: gendisk of interest
203 * @sector: sector to map
204 *
205 * Find out which partition @sector maps to on @disk. This is
206 * primarily used for stats accounting.
207 *
208 * CONTEXT:
209 * RCU read locked. The returned partition pointer is valid only
210 * while preemption is disabled.
211 *
212 * RETURNS:
074a7aca 213 * Found partition on success, part0 is returned if no partition matches
e71bf0d0
TH
214 */
215struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
216{
540eed56 217 struct disk_part_tbl *ptbl;
a6f23657 218 struct hd_struct *part;
e71bf0d0
TH
219 int i;
220
540eed56
TH
221 ptbl = rcu_dereference(disk->part_tbl);
222
a6f23657
JA
223 part = rcu_dereference(ptbl->last_lookup);
224 if (part && sector_in_part(part, sector))
225 return part;
226
540eed56 227 for (i = 1; i < ptbl->len; i++) {
a6f23657 228 part = rcu_dereference(ptbl->part[i]);
e71bf0d0 229
a6f23657
JA
230 if (part && sector_in_part(part, sector)) {
231 rcu_assign_pointer(ptbl->last_lookup, part);
e71bf0d0 232 return part;
a6f23657 233 }
e71bf0d0 234 }
074a7aca 235 return &disk->part0;
e71bf0d0
TH
236}
237EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
238
1da177e4
LT
239/*
240 * Can be deleted altogether. Later.
241 *
242 */
243static struct blk_major_name {
244 struct blk_major_name *next;
245 int major;
246 char name[16];
68eef3b4 247} *major_names[BLKDEV_MAJOR_HASH_SIZE];
1da177e4
LT
248
249/* index in the above - for now: assume no multimajor ranges */
e61eb2e9 250static inline int major_to_index(unsigned major)
1da177e4 251{
68eef3b4 252 return major % BLKDEV_MAJOR_HASH_SIZE;
7170be5f
NH
253}
254
68eef3b4 255#ifdef CONFIG_PROC_FS
cf771cb5 256void blkdev_show(struct seq_file *seqf, off_t offset)
7170be5f 257{
68eef3b4 258 struct blk_major_name *dp;
7170be5f 259
68eef3b4 260 if (offset < BLKDEV_MAJOR_HASH_SIZE) {
edfaa7c3 261 mutex_lock(&block_class_lock);
68eef3b4 262 for (dp = major_names[offset]; dp; dp = dp->next)
cf771cb5 263 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
edfaa7c3 264 mutex_unlock(&block_class_lock);
1da177e4 265 }
1da177e4 266}
68eef3b4 267#endif /* CONFIG_PROC_FS */
1da177e4 268
9e8c0bcc
MN
269/**
270 * register_blkdev - register a new block device
271 *
272 * @major: the requested major device number [1..255]. If @major=0, try to
273 * allocate any unused major number.
274 * @name: the name of the new block device as a zero terminated string
275 *
276 * The @name must be unique within the system.
277 *
278 * The return value depends on the @major input parameter.
279 * - if a major device number was requested in range [1..255] then the
280 * function returns zero on success, or a negative error code
281 * - if any unused major number was requested with @major=0 parameter
282 * then the return value is the allocated major number in range
283 * [1..255] or a negative error code otherwise
284 */
1da177e4
LT
285int register_blkdev(unsigned int major, const char *name)
286{
287 struct blk_major_name **n, *p;
288 int index, ret = 0;
289
edfaa7c3 290 mutex_lock(&block_class_lock);
1da177e4
LT
291
292 /* temporary */
293 if (major == 0) {
294 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
295 if (major_names[index] == NULL)
296 break;
297 }
298
299 if (index == 0) {
300 printk("register_blkdev: failed to get major for %s\n",
301 name);
302 ret = -EBUSY;
303 goto out;
304 }
305 major = index;
306 ret = major;
307 }
308
309 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
310 if (p == NULL) {
311 ret = -ENOMEM;
312 goto out;
313 }
314
315 p->major = major;
316 strlcpy(p->name, name, sizeof(p->name));
317 p->next = NULL;
318 index = major_to_index(major);
319
320 for (n = &major_names[index]; *n; n = &(*n)->next) {
321 if ((*n)->major == major)
322 break;
323 }
324 if (!*n)
325 *n = p;
326 else
327 ret = -EBUSY;
328
329 if (ret < 0) {
330 printk("register_blkdev: cannot get major %d for %s\n",
331 major, name);
332 kfree(p);
333 }
334out:
edfaa7c3 335 mutex_unlock(&block_class_lock);
1da177e4
LT
336 return ret;
337}
338
339EXPORT_SYMBOL(register_blkdev);
340
f4480240 341void unregister_blkdev(unsigned int major, const char *name)
1da177e4
LT
342{
343 struct blk_major_name **n;
344 struct blk_major_name *p = NULL;
345 int index = major_to_index(major);
1da177e4 346
edfaa7c3 347 mutex_lock(&block_class_lock);
1da177e4
LT
348 for (n = &major_names[index]; *n; n = &(*n)->next)
349 if ((*n)->major == major)
350 break;
294462a5
AM
351 if (!*n || strcmp((*n)->name, name)) {
352 WARN_ON(1);
294462a5 353 } else {
1da177e4
LT
354 p = *n;
355 *n = p->next;
356 }
edfaa7c3 357 mutex_unlock(&block_class_lock);
1da177e4 358 kfree(p);
1da177e4
LT
359}
360
361EXPORT_SYMBOL(unregister_blkdev);
362
363static struct kobj_map *bdev_map;
364
870d6656
TH
365/**
366 * blk_mangle_minor - scatter minor numbers apart
367 * @minor: minor number to mangle
368 *
369 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
370 * is enabled. Mangling twice gives the original value.
371 *
372 * RETURNS:
373 * Mangled value.
374 *
375 * CONTEXT:
376 * Don't care.
377 */
378static int blk_mangle_minor(int minor)
379{
380#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
381 int i;
382
383 for (i = 0; i < MINORBITS / 2; i++) {
384 int low = minor & (1 << i);
385 int high = minor & (1 << (MINORBITS - 1 - i));
386 int distance = MINORBITS - 1 - 2 * i;
387
388 minor ^= low | high; /* clear both bits */
389 low <<= distance; /* swap the positions */
390 high >>= distance;
391 minor |= low | high; /* and set */
392 }
393#endif
394 return minor;
395}
396
bcce3de1
TH
397/**
398 * blk_alloc_devt - allocate a dev_t for a partition
399 * @part: partition to allocate dev_t for
bcce3de1
TH
400 * @devt: out parameter for resulting dev_t
401 *
402 * Allocate a dev_t for block device.
403 *
404 * RETURNS:
405 * 0 on success, allocated dev_t is returned in *@devt. -errno on
406 * failure.
407 *
408 * CONTEXT:
409 * Might sleep.
410 */
411int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
412{
413 struct gendisk *disk = part_to_disk(part);
bab998d6 414 int idx;
bcce3de1
TH
415
416 /* in consecutive minor range? */
417 if (part->partno < disk->minors) {
418 *devt = MKDEV(disk->major, disk->first_minor + part->partno);
419 return 0;
420 }
421
422 /* allocate ext devt */
2da78092
KB
423 idr_preload(GFP_KERNEL);
424
425 spin_lock(&ext_devt_lock);
426 idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
427 spin_unlock(&ext_devt_lock);
428
429 idr_preload_end();
bab998d6
TH
430 if (idx < 0)
431 return idx == -ENOSPC ? -EBUSY : idx;
bcce3de1 432
870d6656 433 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
bcce3de1
TH
434 return 0;
435}
436
437/**
438 * blk_free_devt - free a dev_t
439 * @devt: dev_t to free
440 *
441 * Free @devt which was allocated using blk_alloc_devt().
442 *
443 * CONTEXT:
444 * Might sleep.
445 */
446void blk_free_devt(dev_t devt)
447{
bcce3de1
TH
448 if (devt == MKDEV(0, 0))
449 return;
450
451 if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
2da78092 452 spin_lock(&ext_devt_lock);
870d6656 453 idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
2da78092 454 spin_unlock(&ext_devt_lock);
bcce3de1
TH
455 }
456}
457
1f014290
TH
458static char *bdevt_str(dev_t devt, char *buf)
459{
460 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
461 char tbuf[BDEVT_SIZE];
462 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
463 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
464 } else
465 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
466
467 return buf;
468}
469
1da177e4
LT
470/*
471 * Register device numbers dev..(dev+range-1)
472 * range must be nonzero
473 * The hash chain is sorted on range, so that subranges can override.
474 */
edfaa7c3 475void blk_register_region(dev_t devt, unsigned long range, struct module *module,
1da177e4
LT
476 struct kobject *(*probe)(dev_t, int *, void *),
477 int (*lock)(dev_t, void *), void *data)
478{
edfaa7c3 479 kobj_map(bdev_map, devt, range, module, probe, lock, data);
1da177e4
LT
480}
481
482EXPORT_SYMBOL(blk_register_region);
483
edfaa7c3 484void blk_unregister_region(dev_t devt, unsigned long range)
1da177e4 485{
edfaa7c3 486 kobj_unmap(bdev_map, devt, range);
1da177e4
LT
487}
488
489EXPORT_SYMBOL(blk_unregister_region);
490
cf771cb5 491static struct kobject *exact_match(dev_t devt, int *partno, void *data)
1da177e4
LT
492{
493 struct gendisk *p = data;
edfaa7c3 494
ed9e1982 495 return &disk_to_dev(p)->kobj;
1da177e4
LT
496}
497
edfaa7c3 498static int exact_lock(dev_t devt, void *data)
1da177e4
LT
499{
500 struct gendisk *p = data;
501
502 if (!get_disk(p))
503 return -1;
504 return 0;
505}
506
4752bc30 507static void register_disk(struct gendisk *disk)
d2bf1b67
TH
508{
509 struct device *ddev = disk_to_dev(disk);
510 struct block_device *bdev;
511 struct disk_part_iter piter;
512 struct hd_struct *part;
513 int err;
514
515 ddev->parent = disk->driverfs_dev;
516
ffc8b308 517 dev_set_name(ddev, "%s", disk->disk_name);
d2bf1b67
TH
518
519 /* delay uevents, until we scanned partition table */
520 dev_set_uevent_suppress(ddev, 1);
521
522 if (device_add(ddev))
523 return;
524 if (!sysfs_deprecated) {
525 err = sysfs_create_link(block_depr, &ddev->kobj,
526 kobject_name(&ddev->kobj));
527 if (err) {
528 device_del(ddev);
529 return;
530 }
531 }
25e823c8
ML
532
533 /*
534 * avoid probable deadlock caused by allocating memory with
535 * GFP_KERNEL in runtime_resume callback of its all ancestor
536 * devices
537 */
538 pm_runtime_set_memalloc_noio(ddev, true);
539
d2bf1b67
TH
540 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
541 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
542
543 /* No minors to use for partitions */
d27769ec 544 if (!disk_part_scan_enabled(disk))
d2bf1b67
TH
545 goto exit;
546
547 /* No such device (e.g., media were just removed) */
548 if (!get_capacity(disk))
549 goto exit;
550
551 bdev = bdget_disk(disk, 0);
552 if (!bdev)
553 goto exit;
554
555 bdev->bd_invalidated = 1;
556 err = blkdev_get(bdev, FMODE_READ, NULL);
557 if (err < 0)
558 goto exit;
559 blkdev_put(bdev, FMODE_READ);
560
561exit:
562 /* announce disk after possible partitions are created */
563 dev_set_uevent_suppress(ddev, 0);
564 kobject_uevent(&ddev->kobj, KOBJ_ADD);
565
566 /* announce possible partitions */
567 disk_part_iter_init(&piter, disk, 0);
568 while ((part = disk_part_iter_next(&piter)))
569 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
570 disk_part_iter_exit(&piter);
571}
572
1da177e4
LT
573/**
574 * add_disk - add partitioning information to kernel list
575 * @disk: per-device partitioning information
576 *
577 * This function registers the partitioning information in @disk
578 * with the kernel.
3e1a7ff8
TH
579 *
580 * FIXME: error handling
1da177e4
LT
581 */
582void add_disk(struct gendisk *disk)
583{
cf0ca9fe 584 struct backing_dev_info *bdi;
3e1a7ff8 585 dev_t devt;
6ffeea77 586 int retval;
cf0ca9fe 587
3e1a7ff8
TH
588 /* minors == 0 indicates to use ext devt from part0 and should
589 * be accompanied with EXT_DEVT flag. Make sure all
590 * parameters make sense.
591 */
592 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
593 WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
594
1da177e4 595 disk->flags |= GENHD_FL_UP;
3e1a7ff8
TH
596
597 retval = blk_alloc_devt(&disk->part0, &devt);
598 if (retval) {
599 WARN_ON(1);
600 return;
601 }
602 disk_to_dev(disk)->devt = devt;
603
604 /* ->major and ->first_minor aren't supposed to be
605 * dereferenced from here on, but set them just in case.
606 */
607 disk->major = MAJOR(devt);
608 disk->first_minor = MINOR(devt);
609
9f53d2fe
SG
610 disk_alloc_events(disk);
611
9f5e4865 612 /* Register BDI before referencing it from bdev */
01ea5063
SJK
613 bdi = &disk->queue->backing_dev_info;
614 bdi_register_dev(bdi, disk_devt(disk));
615
f331c029
TH
616 blk_register_region(disk_devt(disk), disk->minors, NULL,
617 exact_match, exact_lock, disk);
1da177e4
LT
618 register_disk(disk);
619 blk_register_queue(disk);
cf0ca9fe 620
523e1d39
TH
621 /*
622 * Take an extra ref on queue which will be put on disk_release()
623 * so that it sticks around as long as @disk is there.
624 */
09ac46c4 625 WARN_ON_ONCE(!blk_get_queue(disk->queue));
523e1d39 626
ed9e1982
TH
627 retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
628 "bdi");
6ffeea77 629 WARN_ON(retval);
1da177e4 630
77ea887e 631 disk_add_events(disk);
1da177e4 632}
1da177e4 633EXPORT_SYMBOL(add_disk);
1da177e4 634
d2bf1b67 635void del_gendisk(struct gendisk *disk)
1da177e4 636{
d2bf1b67
TH
637 struct disk_part_iter piter;
638 struct hd_struct *part;
639
77ea887e
TH
640 disk_del_events(disk);
641
d2bf1b67
TH
642 /* invalidate stuff */
643 disk_part_iter_init(&piter, disk,
644 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
645 while ((part = disk_part_iter_next(&piter))) {
646 invalidate_partition(disk, part->partno);
647 delete_partition(disk, part->partno);
648 }
649 disk_part_iter_exit(&piter);
650
651 invalidate_partition(disk, 0);
d2bf1b67
TH
652 set_capacity(disk, 0);
653 disk->flags &= ~GENHD_FL_UP;
654
ed9e1982 655 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
cf0ca9fe 656 bdi_unregister(&disk->queue->backing_dev_info);
1da177e4 657 blk_unregister_queue(disk);
f331c029 658 blk_unregister_region(disk_devt(disk), disk->minors);
d2bf1b67
TH
659
660 part_stat_set_all(&disk->part0, 0);
661 disk->part0.stamp = 0;
662
663 kobject_put(disk->part0.holder_dir);
664 kobject_put(disk->slave_dir);
665 disk->driverfs_dev = NULL;
666 if (!sysfs_deprecated)
667 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
25e823c8 668 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
d2bf1b67 669 device_del(disk_to_dev(disk));
1da177e4 670}
d2bf1b67 671EXPORT_SYMBOL(del_gendisk);
1da177e4 672
1da177e4
LT
673/**
674 * get_gendisk - get partitioning information for a given device
710027a4 675 * @devt: device to get partitioning information for
496aa8a9 676 * @partno: returned partition index
1da177e4
LT
677 *
678 * This function gets the structure containing partitioning
710027a4 679 * information for the given device @devt.
1da177e4 680 */
cf771cb5 681struct gendisk *get_gendisk(dev_t devt, int *partno)
1da177e4 682{
bcce3de1
TH
683 struct gendisk *disk = NULL;
684
685 if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
686 struct kobject *kobj;
687
688 kobj = kobj_lookup(bdev_map, devt, partno);
689 if (kobj)
690 disk = dev_to_disk(kobj_to_dev(kobj));
691 } else {
692 struct hd_struct *part;
693
2da78092 694 spin_lock(&ext_devt_lock);
870d6656 695 part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
bcce3de1
TH
696 if (part && get_disk(part_to_disk(part))) {
697 *partno = part->partno;
698 disk = part_to_disk(part);
699 }
2da78092 700 spin_unlock(&ext_devt_lock);
bcce3de1 701 }
edfaa7c3 702
bcce3de1 703 return disk;
1da177e4 704}
b6ac23af 705EXPORT_SYMBOL(get_gendisk);
1da177e4 706
f331c029
TH
707/**
708 * bdget_disk - do bdget() by gendisk and partition number
709 * @disk: gendisk of interest
710 * @partno: partition number
711 *
712 * Find partition @partno from @disk, do bdget() on it.
713 *
714 * CONTEXT:
715 * Don't care.
716 *
717 * RETURNS:
718 * Resulting block_device on success, NULL on failure.
719 */
aeb3d3a8 720struct block_device *bdget_disk(struct gendisk *disk, int partno)
f331c029 721{
548b10eb
TH
722 struct hd_struct *part;
723 struct block_device *bdev = NULL;
f331c029 724
548b10eb 725 part = disk_get_part(disk, partno);
2bbedcb4 726 if (part)
548b10eb
TH
727 bdev = bdget(part_devt(part));
728 disk_put_part(part);
f331c029 729
548b10eb 730 return bdev;
f331c029
TH
731}
732EXPORT_SYMBOL(bdget_disk);
733
5c6f35c5
GKH
734/*
735 * print a full list of all partitions - intended for places where the root
736 * filesystem can't be mounted and thus to give the victim some idea of what
737 * went wrong
738 */
739void __init printk_all_partitions(void)
740{
def4e38d
TH
741 struct class_dev_iter iter;
742 struct device *dev;
743
744 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
745 while ((dev = class_dev_iter_next(&iter))) {
746 struct gendisk *disk = dev_to_disk(dev);
e71bf0d0
TH
747 struct disk_part_iter piter;
748 struct hd_struct *part;
1f014290
TH
749 char name_buf[BDEVNAME_SIZE];
750 char devt_buf[BDEVT_SIZE];
def4e38d
TH
751
752 /*
753 * Don't show empty devices or things that have been
25985edc 754 * suppressed
def4e38d
TH
755 */
756 if (get_capacity(disk) == 0 ||
757 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
758 continue;
759
760 /*
761 * Note, unlike /proc/partitions, I am showing the
762 * numbers in hex - the same format as the root=
763 * option takes.
764 */
074a7aca
TH
765 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
766 while ((part = disk_part_iter_next(&piter))) {
767 bool is_part0 = part == &disk->part0;
def4e38d 768
b5af921e 769 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
1f014290 770 bdevt_str(part_devt(part), devt_buf),
c83f6bf9
VG
771 (unsigned long long)part_nr_sects_read(part) >> 1
772 , disk_name(disk, part->partno, name_buf),
1ad7e899 773 part->info ? part->info->uuid : "");
074a7aca
TH
774 if (is_part0) {
775 if (disk->driverfs_dev != NULL &&
776 disk->driverfs_dev->driver != NULL)
777 printk(" driver: %s\n",
778 disk->driverfs_dev->driver->name);
779 else
780 printk(" (driver?)\n");
781 } else
782 printk("\n");
783 }
e71bf0d0 784 disk_part_iter_exit(&piter);
def4e38d
TH
785 }
786 class_dev_iter_exit(&iter);
dd2a345f
DG
787}
788
1da177e4
LT
789#ifdef CONFIG_PROC_FS
790/* iterator */
def4e38d 791static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
68c4d4a7 792{
def4e38d
TH
793 loff_t skip = *pos;
794 struct class_dev_iter *iter;
795 struct device *dev;
68c4d4a7 796
aeb3d3a8 797 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
def4e38d
TH
798 if (!iter)
799 return ERR_PTR(-ENOMEM);
800
801 seqf->private = iter;
802 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
803 do {
804 dev = class_dev_iter_next(iter);
805 if (!dev)
806 return NULL;
807 } while (skip--);
808
809 return dev_to_disk(dev);
68c4d4a7
GKH
810}
811
def4e38d 812static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
1da177e4 813{
edfaa7c3 814 struct device *dev;
1da177e4 815
def4e38d
TH
816 (*pos)++;
817 dev = class_dev_iter_next(seqf->private);
2ac3cee5 818 if (dev)
68c4d4a7 819 return dev_to_disk(dev);
2ac3cee5 820
1da177e4
LT
821 return NULL;
822}
823
def4e38d 824static void disk_seqf_stop(struct seq_file *seqf, void *v)
27f30251 825{
def4e38d 826 struct class_dev_iter *iter = seqf->private;
27f30251 827
def4e38d
TH
828 /* stop is called even after start failed :-( */
829 if (iter) {
830 class_dev_iter_exit(iter);
831 kfree(iter);
5c0ef6d0 832 }
1da177e4
LT
833}
834
def4e38d 835static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
1da177e4 836{
06768067 837 void *p;
def4e38d
TH
838
839 p = disk_seqf_start(seqf, pos);
b9f985b6 840 if (!IS_ERR_OR_NULL(p) && !*pos)
def4e38d
TH
841 seq_puts(seqf, "major minor #blocks name\n\n");
842 return p;
1da177e4
LT
843}
844
cf771cb5 845static int show_partition(struct seq_file *seqf, void *v)
1da177e4
LT
846{
847 struct gendisk *sgp = v;
e71bf0d0
TH
848 struct disk_part_iter piter;
849 struct hd_struct *part;
1da177e4
LT
850 char buf[BDEVNAME_SIZE];
851
1da177e4 852 /* Don't show non-partitionable removeable devices or empty devices */
d27769ec 853 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
f331c029 854 (sgp->flags & GENHD_FL_REMOVABLE)))
1da177e4
LT
855 return 0;
856 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
857 return 0;
858
859 /* show the full disk and all non-0 size partitions of it */
074a7aca 860 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
e71bf0d0 861 while ((part = disk_part_iter_next(&piter)))
1f014290 862 seq_printf(seqf, "%4d %7d %10llu %s\n",
f331c029 863 MAJOR(part_devt(part)), MINOR(part_devt(part)),
c83f6bf9 864 (unsigned long long)part_nr_sects_read(part) >> 1,
f331c029 865 disk_name(sgp, part->partno, buf));
e71bf0d0 866 disk_part_iter_exit(&piter);
1da177e4
LT
867
868 return 0;
869}
870
f500975a 871static const struct seq_operations partitions_op = {
def4e38d
TH
872 .start = show_partition_start,
873 .next = disk_seqf_next,
874 .stop = disk_seqf_stop,
edfaa7c3 875 .show = show_partition
1da177e4 876};
f500975a
AD
877
878static int partitions_open(struct inode *inode, struct file *file)
879{
880 return seq_open(file, &partitions_op);
881}
882
883static const struct file_operations proc_partitions_operations = {
884 .open = partitions_open,
885 .read = seq_read,
886 .llseek = seq_lseek,
887 .release = seq_release,
888};
1da177e4
LT
889#endif
890
891
cf771cb5 892static struct kobject *base_probe(dev_t devt, int *partno, void *data)
1da177e4 893{
edfaa7c3 894 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
1da177e4 895 /* Make old-style 2.4 aliases work */
edfaa7c3 896 request_module("block-major-%d", MAJOR(devt));
1da177e4
LT
897 return NULL;
898}
899
900static int __init genhd_device_init(void)
901{
e105b8bf
DW
902 int error;
903
904 block_class.dev_kobj = sysfs_dev_block_kobj;
905 error = class_register(&block_class);
ee27a558
RM
906 if (unlikely(error))
907 return error;
edfaa7c3 908 bdev_map = kobj_map_init(base_probe, &block_class_lock);
1da177e4 909 blk_dev_init();
edfaa7c3 910
561ec68e
ZY
911 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
912
edfaa7c3 913 /* create top-level block dir */
e52eec13
AK
914 if (!sysfs_deprecated)
915 block_depr = kobject_create_and_add("block", NULL);
830d3cfb 916 return 0;
1da177e4
LT
917}
918
919subsys_initcall(genhd_device_init);
920
edfaa7c3
KS
921static ssize_t disk_range_show(struct device *dev,
922 struct device_attribute *attr, char *buf)
1da177e4 923{
edfaa7c3 924 struct gendisk *disk = dev_to_disk(dev);
1da177e4 925
edfaa7c3 926 return sprintf(buf, "%d\n", disk->minors);
1da177e4
LT
927}
928
1f014290
TH
929static ssize_t disk_ext_range_show(struct device *dev,
930 struct device_attribute *attr, char *buf)
931{
932 struct gendisk *disk = dev_to_disk(dev);
933
b5d0b9df 934 return sprintf(buf, "%d\n", disk_max_parts(disk));
1f014290
TH
935}
936
edfaa7c3
KS
937static ssize_t disk_removable_show(struct device *dev,
938 struct device_attribute *attr, char *buf)
a7fd6706 939{
edfaa7c3 940 struct gendisk *disk = dev_to_disk(dev);
a7fd6706 941
edfaa7c3
KS
942 return sprintf(buf, "%d\n",
943 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
a7fd6706
KS
944}
945
1c9ce527
KS
946static ssize_t disk_ro_show(struct device *dev,
947 struct device_attribute *attr, char *buf)
948{
949 struct gendisk *disk = dev_to_disk(dev);
950
b7db9956 951 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1c9ce527
KS
952}
953
edfaa7c3
KS
954static ssize_t disk_capability_show(struct device *dev,
955 struct device_attribute *attr, char *buf)
86ce18d7 956{
edfaa7c3
KS
957 struct gendisk *disk = dev_to_disk(dev);
958
959 return sprintf(buf, "%x\n", disk->flags);
86ce18d7 960}
edfaa7c3 961
c72758f3
MP
962static ssize_t disk_alignment_offset_show(struct device *dev,
963 struct device_attribute *attr,
964 char *buf)
965{
966 struct gendisk *disk = dev_to_disk(dev);
967
968 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
969}
970
86b37281
MP
971static ssize_t disk_discard_alignment_show(struct device *dev,
972 struct device_attribute *attr,
973 char *buf)
974{
975 struct gendisk *disk = dev_to_disk(dev);
976
dd3d145d 977 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
86b37281
MP
978}
979
edfaa7c3 980static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
1f014290 981static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL);
edfaa7c3 982static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
1c9ce527 983static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
e5610521 984static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
c72758f3 985static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL);
86b37281
MP
986static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show,
987 NULL);
edfaa7c3 988static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
074a7aca 989static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
316d315b 990static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
c17bb495 991#ifdef CONFIG_FAIL_MAKE_REQUEST
edfaa7c3 992static struct device_attribute dev_attr_fail =
eddb2e26 993 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
c17bb495 994#endif
581d4e28
JA
995#ifdef CONFIG_FAIL_IO_TIMEOUT
996static struct device_attribute dev_attr_fail_timeout =
997 __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show,
998 part_timeout_store);
999#endif
edfaa7c3
KS
1000
1001static struct attribute *disk_attrs[] = {
1002 &dev_attr_range.attr,
1f014290 1003 &dev_attr_ext_range.attr,
edfaa7c3 1004 &dev_attr_removable.attr,
1c9ce527 1005 &dev_attr_ro.attr,
edfaa7c3 1006 &dev_attr_size.attr,
c72758f3 1007 &dev_attr_alignment_offset.attr,
86b37281 1008 &dev_attr_discard_alignment.attr,
edfaa7c3
KS
1009 &dev_attr_capability.attr,
1010 &dev_attr_stat.attr,
316d315b 1011 &dev_attr_inflight.attr,
edfaa7c3
KS
1012#ifdef CONFIG_FAIL_MAKE_REQUEST
1013 &dev_attr_fail.attr,
581d4e28
JA
1014#endif
1015#ifdef CONFIG_FAIL_IO_TIMEOUT
1016 &dev_attr_fail_timeout.attr,
edfaa7c3
KS
1017#endif
1018 NULL
1019};
1020
1021static struct attribute_group disk_attr_group = {
1022 .attrs = disk_attrs,
1023};
1024
a4dbd674 1025static const struct attribute_group *disk_attr_groups[] = {
edfaa7c3
KS
1026 &disk_attr_group,
1027 NULL
1da177e4
LT
1028};
1029
540eed56
TH
1030/**
1031 * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way
1032 * @disk: disk to replace part_tbl for
1033 * @new_ptbl: new part_tbl to install
1034 *
1035 * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The
1036 * original ptbl is freed using RCU callback.
1037 *
1038 * LOCKING:
1039 * Matching bd_mutx locked.
1040 */
1041static void disk_replace_part_tbl(struct gendisk *disk,
1042 struct disk_part_tbl *new_ptbl)
1043{
1044 struct disk_part_tbl *old_ptbl = disk->part_tbl;
1045
1046 rcu_assign_pointer(disk->part_tbl, new_ptbl);
a6f23657
JA
1047
1048 if (old_ptbl) {
1049 rcu_assign_pointer(old_ptbl->last_lookup, NULL);
57bdfbf9 1050 kfree_rcu(old_ptbl, rcu_head);
a6f23657 1051 }
540eed56
TH
1052}
1053
1054/**
1055 * disk_expand_part_tbl - expand disk->part_tbl
1056 * @disk: disk to expand part_tbl for
1057 * @partno: expand such that this partno can fit in
1058 *
1059 * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl
1060 * uses RCU to allow unlocked dereferencing for stats and other stuff.
1061 *
1062 * LOCKING:
1063 * Matching bd_mutex locked, might sleep.
1064 *
1065 * RETURNS:
1066 * 0 on success, -errno on failure.
1067 */
1068int disk_expand_part_tbl(struct gendisk *disk, int partno)
1069{
1070 struct disk_part_tbl *old_ptbl = disk->part_tbl;
1071 struct disk_part_tbl *new_ptbl;
1072 int len = old_ptbl ? old_ptbl->len : 0;
1073 int target = partno + 1;
1074 size_t size;
1075 int i;
1076
1077 /* disk_max_parts() is zero during initialization, ignore if so */
1078 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1079 return -EINVAL;
1080
1081 if (target <= len)
1082 return 0;
1083
1084 size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
1085 new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
1086 if (!new_ptbl)
1087 return -ENOMEM;
1088
540eed56
TH
1089 new_ptbl->len = target;
1090
1091 for (i = 0; i < len; i++)
1092 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1093
1094 disk_replace_part_tbl(disk, new_ptbl);
1095 return 0;
1096}
1097
edfaa7c3 1098static void disk_release(struct device *dev)
1da177e4 1099{
edfaa7c3
KS
1100 struct gendisk *disk = dev_to_disk(dev);
1101
2da78092 1102 blk_free_devt(dev->devt);
77ea887e 1103 disk_release_events(disk);
1da177e4 1104 kfree(disk->random);
540eed56 1105 disk_replace_part_tbl(disk, NULL);
074a7aca 1106 free_part_stats(&disk->part0);
6d1d8050 1107 free_part_info(&disk->part0);
523e1d39
TH
1108 if (disk->queue)
1109 blk_put_queue(disk->queue);
1da177e4
LT
1110 kfree(disk);
1111}
edfaa7c3
KS
1112struct class block_class = {
1113 .name = "block",
1da177e4
LT
1114};
1115
3c2670e6 1116static char *block_devnode(struct device *dev, umode_t *mode,
4e4098a3 1117 kuid_t *uid, kgid_t *gid)
b03f38b6
KS
1118{
1119 struct gendisk *disk = dev_to_disk(dev);
1120
e454cea2
KS
1121 if (disk->devnode)
1122 return disk->devnode(disk, mode);
b03f38b6
KS
1123 return NULL;
1124}
1125
1826eadf 1126static struct device_type disk_type = {
edfaa7c3
KS
1127 .name = "disk",
1128 .groups = disk_attr_groups,
1129 .release = disk_release,
e454cea2 1130 .devnode = block_devnode,
1da177e4
LT
1131};
1132
a6e2ba88 1133#ifdef CONFIG_PROC_FS
cf771cb5
TH
1134/*
1135 * aggregate disk stat collector. Uses the same stats that the sysfs
1136 * entries do, above, but makes them available through one seq_file.
1137 *
1138 * The output looks suspiciously like /proc/partitions with a bunch of
1139 * extra fields.
1140 */
1141static int diskstats_show(struct seq_file *seqf, void *v)
1da177e4
LT
1142{
1143 struct gendisk *gp = v;
e71bf0d0
TH
1144 struct disk_part_iter piter;
1145 struct hd_struct *hd;
1da177e4 1146 char buf[BDEVNAME_SIZE];
c9959059 1147 int cpu;
1da177e4
LT
1148
1149 /*
ed9e1982 1150 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
cf771cb5 1151 seq_puts(seqf, "major minor name"
1da177e4
LT
1152 " rio rmerge rsect ruse wio wmerge "
1153 "wsect wuse running use aveq"
1154 "\n\n");
1155 */
9f5e4865 1156
71982a40 1157 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
e71bf0d0 1158 while ((hd = disk_part_iter_next(&piter))) {
074a7aca 1159 cpu = part_stat_lock();
c9959059 1160 part_round_stats(cpu, hd);
074a7aca 1161 part_stat_unlock();
f95fe9cf
HP
1162 seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
1163 "%u %lu %lu %lu %u %u %u %u\n",
f331c029
TH
1164 MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
1165 disk_name(gp, hd->partno, buf),
53f22956
LY
1166 part_stat_read(hd, ios[READ]),
1167 part_stat_read(hd, merges[READ]),
f95fe9cf 1168 part_stat_read(hd, sectors[READ]),
53f22956
LY
1169 jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
1170 part_stat_read(hd, ios[WRITE]),
1171 part_stat_read(hd, merges[WRITE]),
f95fe9cf 1172 part_stat_read(hd, sectors[WRITE]),
53f22956 1173 jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
316d315b 1174 part_in_flight(hd),
28f39d55
JM
1175 jiffies_to_msecs(part_stat_read(hd, io_ticks)),
1176 jiffies_to_msecs(part_stat_read(hd, time_in_queue))
1177 );
1da177e4 1178 }
e71bf0d0 1179 disk_part_iter_exit(&piter);
9f5e4865 1180
1da177e4
LT
1181 return 0;
1182}
1183
31d85ab2 1184static const struct seq_operations diskstats_op = {
def4e38d
TH
1185 .start = disk_seqf_start,
1186 .next = disk_seqf_next,
1187 .stop = disk_seqf_stop,
1da177e4
LT
1188 .show = diskstats_show
1189};
f500975a 1190
31d85ab2
AD
1191static int diskstats_open(struct inode *inode, struct file *file)
1192{
1193 return seq_open(file, &diskstats_op);
1194}
1195
1196static const struct file_operations proc_diskstats_operations = {
1197 .open = diskstats_open,
1198 .read = seq_read,
1199 .llseek = seq_lseek,
1200 .release = seq_release,
1201};
1202
f500975a
AD
1203static int __init proc_genhd_init(void)
1204{
31d85ab2 1205 proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
f500975a
AD
1206 proc_create("partitions", 0, NULL, &proc_partitions_operations);
1207 return 0;
1208}
1209module_init(proc_genhd_init);
a6e2ba88 1210#endif /* CONFIG_PROC_FS */
1da177e4 1211
cf771cb5 1212dev_t blk_lookup_devt(const char *name, int partno)
a142be85 1213{
def4e38d
TH
1214 dev_t devt = MKDEV(0, 0);
1215 struct class_dev_iter iter;
1216 struct device *dev;
a142be85 1217
def4e38d
TH
1218 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1219 while ((dev = class_dev_iter_next(&iter))) {
a142be85 1220 struct gendisk *disk = dev_to_disk(dev);
548b10eb 1221 struct hd_struct *part;
a142be85 1222
3ada8b7e 1223 if (strcmp(dev_name(dev), name))
f331c029 1224 continue;
f331c029 1225
41b8c853
NB
1226 if (partno < disk->minors) {
1227 /* We need to return the right devno, even
1228 * if the partition doesn't exist yet.
1229 */
1230 devt = MKDEV(MAJOR(dev->devt),
1231 MINOR(dev->devt) + partno);
1232 break;
1233 }
548b10eb 1234 part = disk_get_part(disk, partno);
2bbedcb4 1235 if (part) {
f331c029 1236 devt = part_devt(part);
e71bf0d0 1237 disk_put_part(part);
548b10eb 1238 break;
def4e38d 1239 }
548b10eb 1240 disk_put_part(part);
5c0ef6d0 1241 }
def4e38d 1242 class_dev_iter_exit(&iter);
edfaa7c3
KS
1243 return devt;
1244}
edfaa7c3
KS
1245EXPORT_SYMBOL(blk_lookup_devt);
1246
1da177e4
LT
1247struct gendisk *alloc_disk(int minors)
1248{
c304a51b 1249 return alloc_disk_node(minors, NUMA_NO_NODE);
1946089a 1250}
689d6fac 1251EXPORT_SYMBOL(alloc_disk);
1946089a
CL
1252
1253struct gendisk *alloc_disk_node(int minors, int node_id)
1254{
1255 struct gendisk *disk;
1256
c1b511eb 1257 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1da177e4 1258 if (disk) {
074a7aca 1259 if (!init_part_stats(&disk->part0)) {
1da177e4
LT
1260 kfree(disk);
1261 return NULL;
1262 }
bf91db18 1263 disk->node_id = node_id;
540eed56
TH
1264 if (disk_expand_part_tbl(disk, 0)) {
1265 free_part_stats(&disk->part0);
b5d0b9df
TH
1266 kfree(disk);
1267 return NULL;
1da177e4 1268 }
540eed56 1269 disk->part_tbl->part[0] = &disk->part0;
6c23a968 1270
c83f6bf9
VG
1271 /*
1272 * set_capacity() and get_capacity() currently don't use
1273 * seqcounter to read/update the part0->nr_sects. Still init
1274 * the counter as we can read the sectors in IO submission
1275 * patch using seqence counters.
1276 *
1277 * TODO: Ideally set_capacity() and get_capacity() should be
1278 * converted to make use of bd_mutex and sequence counters.
1279 */
1280 seqcount_init(&disk->part0.nr_sects_seq);
6c23a968 1281 hd_ref_init(&disk->part0);
b5d0b9df 1282
1da177e4 1283 disk->minors = minors;
1da177e4 1284 rand_initialize_disk(disk);
ed9e1982
TH
1285 disk_to_dev(disk)->class = &block_class;
1286 disk_to_dev(disk)->type = &disk_type;
1287 device_initialize(disk_to_dev(disk));
1da177e4
LT
1288 }
1289 return disk;
1290}
1946089a 1291EXPORT_SYMBOL(alloc_disk_node);
1da177e4
LT
1292
1293struct kobject *get_disk(struct gendisk *disk)
1294{
1295 struct module *owner;
1296 struct kobject *kobj;
1297
1298 if (!disk->fops)
1299 return NULL;
1300 owner = disk->fops->owner;
1301 if (owner && !try_module_get(owner))
1302 return NULL;
ed9e1982 1303 kobj = kobject_get(&disk_to_dev(disk)->kobj);
1da177e4
LT
1304 if (kobj == NULL) {
1305 module_put(owner);
1306 return NULL;
1307 }
1308 return kobj;
1309
1310}
1311
1312EXPORT_SYMBOL(get_disk);
1313
1314void put_disk(struct gendisk *disk)
1315{
1316 if (disk)
ed9e1982 1317 kobject_put(&disk_to_dev(disk)->kobj);
1da177e4
LT
1318}
1319
1320EXPORT_SYMBOL(put_disk);
1321
e3264a4d
HR
1322static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1323{
1324 char event[] = "DISK_RO=1";
1325 char *envp[] = { event, NULL };
1326
1327 if (!ro)
1328 event[8] = '0';
1329 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1330}
1331
1da177e4
LT
1332void set_device_ro(struct block_device *bdev, int flag)
1333{
b7db9956 1334 bdev->bd_part->policy = flag;
1da177e4
LT
1335}
1336
1337EXPORT_SYMBOL(set_device_ro);
1338
1339void set_disk_ro(struct gendisk *disk, int flag)
1340{
e71bf0d0
TH
1341 struct disk_part_iter piter;
1342 struct hd_struct *part;
1343
e3264a4d
HR
1344 if (disk->part0.policy != flag) {
1345 set_disk_ro_uevent(disk, flag);
1346 disk->part0.policy = flag;
1347 }
1348
1349 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
e71bf0d0
TH
1350 while ((part = disk_part_iter_next(&piter)))
1351 part->policy = flag;
1352 disk_part_iter_exit(&piter);
1da177e4
LT
1353}
1354
1355EXPORT_SYMBOL(set_disk_ro);
1356
1357int bdev_read_only(struct block_device *bdev)
1358{
1359 if (!bdev)
1360 return 0;
b7db9956 1361 return bdev->bd_part->policy;
1da177e4
LT
1362}
1363
1364EXPORT_SYMBOL(bdev_read_only);
1365
cf771cb5 1366int invalidate_partition(struct gendisk *disk, int partno)
1da177e4
LT
1367{
1368 int res = 0;
cf771cb5 1369 struct block_device *bdev = bdget_disk(disk, partno);
1da177e4 1370 if (bdev) {
2ef41634 1371 fsync_bdev(bdev);
93b270f7 1372 res = __invalidate_device(bdev, true);
1da177e4
LT
1373 bdput(bdev);
1374 }
1375 return res;
1376}
1377
1378EXPORT_SYMBOL(invalidate_partition);
77ea887e
TH
1379
1380/*
1381 * Disk events - monitor disk events like media change and eject request.
1382 */
1383struct disk_events {
1384 struct list_head node; /* all disk_event's */
1385 struct gendisk *disk; /* the associated disk */
1386 spinlock_t lock;
1387
fdd514e1 1388 struct mutex block_mutex; /* protects blocking */
77ea887e
TH
1389 int block; /* event blocking depth */
1390 unsigned int pending; /* events already sent out */
1391 unsigned int clearing; /* events being cleared */
1392
1393 long poll_msecs; /* interval, -1 for default */
1394 struct delayed_work dwork;
1395};
1396
1397static const char *disk_events_strs[] = {
1398 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1399 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1400};
1401
1402static char *disk_uevents[] = {
1403 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1404 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1405};
1406
1407/* list of all disk_events */
1408static DEFINE_MUTEX(disk_events_mutex);
1409static LIST_HEAD(disk_events);
1410
1411/* disable in-kernel polling by default */
1412static unsigned long disk_events_dfl_poll_msecs = 0;
1413
1414static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1415{
1416 struct disk_events *ev = disk->ev;
1417 long intv_msecs = 0;
1418
1419 /*
1420 * If device-specific poll interval is set, always use it. If
1421 * the default is being used, poll iff there are events which
1422 * can't be monitored asynchronously.
1423 */
1424 if (ev->poll_msecs >= 0)
1425 intv_msecs = ev->poll_msecs;
1426 else if (disk->events & ~disk->async_events)
1427 intv_msecs = disk_events_dfl_poll_msecs;
1428
1429 return msecs_to_jiffies(intv_msecs);
1430}
1431
c3af54af
TH
1432/**
1433 * disk_block_events - block and flush disk event checking
1434 * @disk: disk to block events for
1435 *
1436 * On return from this function, it is guaranteed that event checking
1437 * isn't in progress and won't happen until unblocked by
1438 * disk_unblock_events(). Events blocking is counted and the actual
1439 * unblocking happens after the matching number of unblocks are done.
1440 *
1441 * Note that this intentionally does not block event checking from
1442 * disk_clear_events().
1443 *
1444 * CONTEXT:
1445 * Might sleep.
1446 */
1447void disk_block_events(struct gendisk *disk)
77ea887e
TH
1448{
1449 struct disk_events *ev = disk->ev;
1450 unsigned long flags;
1451 bool cancel;
1452
c3af54af
TH
1453 if (!ev)
1454 return;
1455
fdd514e1
TH
1456 /*
1457 * Outer mutex ensures that the first blocker completes canceling
1458 * the event work before further blockers are allowed to finish.
1459 */
1460 mutex_lock(&ev->block_mutex);
1461
77ea887e
TH
1462 spin_lock_irqsave(&ev->lock, flags);
1463 cancel = !ev->block++;
1464 spin_unlock_irqrestore(&ev->lock, flags);
1465
c3af54af
TH
1466 if (cancel)
1467 cancel_delayed_work_sync(&disk->ev->dwork);
fdd514e1
TH
1468
1469 mutex_unlock(&ev->block_mutex);
77ea887e
TH
1470}
1471
1472static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1473{
1474 struct disk_events *ev = disk->ev;
1475 unsigned long intv;
1476 unsigned long flags;
1477
1478 spin_lock_irqsave(&ev->lock, flags);
1479
1480 if (WARN_ON_ONCE(ev->block <= 0))
1481 goto out_unlock;
1482
1483 if (--ev->block)
1484 goto out_unlock;
1485
1486 /*
1487 * Not exactly a latency critical operation, set poll timer
1488 * slack to 25% and kick event check.
1489 */
1490 intv = disk_events_poll_jiffies(disk);
1491 set_timer_slack(&ev->dwork.timer, intv / 4);
1492 if (check_now)
695588f9
VK
1493 queue_delayed_work(system_freezable_power_efficient_wq,
1494 &ev->dwork, 0);
77ea887e 1495 else if (intv)
695588f9
VK
1496 queue_delayed_work(system_freezable_power_efficient_wq,
1497 &ev->dwork, intv);
77ea887e
TH
1498out_unlock:
1499 spin_unlock_irqrestore(&ev->lock, flags);
1500}
1501
77ea887e
TH
1502/**
1503 * disk_unblock_events - unblock disk event checking
1504 * @disk: disk to unblock events for
1505 *
1506 * Undo disk_block_events(). When the block count reaches zero, it
1507 * starts events polling if configured.
1508 *
1509 * CONTEXT:
1510 * Don't care. Safe to call from irq context.
1511 */
1512void disk_unblock_events(struct gendisk *disk)
1513{
1514 if (disk->ev)
facc31dd 1515 __disk_unblock_events(disk, false);
77ea887e
TH
1516}
1517
1518/**
85ef06d1
TH
1519 * disk_flush_events - schedule immediate event checking and flushing
1520 * @disk: disk to check and flush events for
1521 * @mask: events to flush
77ea887e 1522 *
85ef06d1
TH
1523 * Schedule immediate event checking on @disk if not blocked. Events in
1524 * @mask are scheduled to be cleared from the driver. Note that this
1525 * doesn't clear the events from @disk->ev.
77ea887e
TH
1526 *
1527 * CONTEXT:
85ef06d1 1528 * If @mask is non-zero must be called with bdev->bd_mutex held.
77ea887e 1529 */
85ef06d1 1530void disk_flush_events(struct gendisk *disk, unsigned int mask)
77ea887e 1531{
a9dce2a3 1532 struct disk_events *ev = disk->ev;
a9dce2a3
TH
1533
1534 if (!ev)
1535 return;
1536
85ef06d1
TH
1537 spin_lock_irq(&ev->lock);
1538 ev->clearing |= mask;
41f63c53 1539 if (!ev->block)
695588f9
VK
1540 mod_delayed_work(system_freezable_power_efficient_wq,
1541 &ev->dwork, 0);
85ef06d1 1542 spin_unlock_irq(&ev->lock);
77ea887e 1543}
77ea887e
TH
1544
1545/**
1546 * disk_clear_events - synchronously check, clear and return pending events
1547 * @disk: disk to fetch and clear events from
da3dae54 1548 * @mask: mask of events to be fetched and cleared
77ea887e
TH
1549 *
1550 * Disk events are synchronously checked and pending events in @mask
1551 * are cleared and returned. This ignores the block count.
1552 *
1553 * CONTEXT:
1554 * Might sleep.
1555 */
1556unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1557{
1558 const struct block_device_operations *bdops = disk->fops;
1559 struct disk_events *ev = disk->ev;
1560 unsigned int pending;
12c2bdb2 1561 unsigned int clearing = mask;
77ea887e
TH
1562
1563 if (!ev) {
1564 /* for drivers still using the old ->media_changed method */
1565 if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
1566 bdops->media_changed && bdops->media_changed(disk))
1567 return DISK_EVENT_MEDIA_CHANGE;
1568 return 0;
1569 }
1570
12c2bdb2
DB
1571 disk_block_events(disk);
1572
1573 /*
1574 * store the union of mask and ev->clearing on the stack so that the
1575 * race with disk_flush_events does not cause ambiguity (ev->clearing
1576 * can still be modified even if events are blocked).
1577 */
77ea887e 1578 spin_lock_irq(&ev->lock);
12c2bdb2
DB
1579 clearing |= ev->clearing;
1580 ev->clearing = 0;
77ea887e
TH
1581 spin_unlock_irq(&ev->lock);
1582
12c2bdb2 1583 disk_check_events(ev, &clearing);
aea24a8b 1584 /*
12c2bdb2
DB
1585 * if ev->clearing is not 0, the disk_flush_events got called in the
1586 * middle of this function, so we want to run the workfn without delay.
aea24a8b 1587 */
12c2bdb2 1588 __disk_unblock_events(disk, ev->clearing ? true : false);
77ea887e
TH
1589
1590 /* then, fetch and clear pending events */
1591 spin_lock_irq(&ev->lock);
77ea887e
TH
1592 pending = ev->pending & mask;
1593 ev->pending &= ~mask;
1594 spin_unlock_irq(&ev->lock);
12c2bdb2 1595 WARN_ON_ONCE(clearing & mask);
77ea887e
TH
1596
1597 return pending;
1598}
1599
12c2bdb2
DB
1600/*
1601 * Separate this part out so that a different pointer for clearing_ptr can be
1602 * passed in for disk_clear_events.
1603 */
77ea887e
TH
1604static void disk_events_workfn(struct work_struct *work)
1605{
1606 struct delayed_work *dwork = to_delayed_work(work);
1607 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
12c2bdb2
DB
1608
1609 disk_check_events(ev, &ev->clearing);
1610}
1611
1612static void disk_check_events(struct disk_events *ev,
1613 unsigned int *clearing_ptr)
1614{
77ea887e
TH
1615 struct gendisk *disk = ev->disk;
1616 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
12c2bdb2 1617 unsigned int clearing = *clearing_ptr;
77ea887e
TH
1618 unsigned int events;
1619 unsigned long intv;
1620 int nr_events = 0, i;
1621
1622 /* check events */
1623 events = disk->fops->check_events(disk, clearing);
1624
1625 /* accumulate pending events and schedule next poll if necessary */
1626 spin_lock_irq(&ev->lock);
1627
1628 events &= ~ev->pending;
1629 ev->pending |= events;
12c2bdb2 1630 *clearing_ptr &= ~clearing;
77ea887e
TH
1631
1632 intv = disk_events_poll_jiffies(disk);
1633 if (!ev->block && intv)
695588f9
VK
1634 queue_delayed_work(system_freezable_power_efficient_wq,
1635 &ev->dwork, intv);
77ea887e
TH
1636
1637 spin_unlock_irq(&ev->lock);
1638
7c88a168
TH
1639 /*
1640 * Tell userland about new events. Only the events listed in
1641 * @disk->events are reported. Unlisted events are processed the
1642 * same internally but never get reported to userland.
1643 */
77ea887e 1644 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
7c88a168 1645 if (events & disk->events & (1 << i))
77ea887e
TH
1646 envp[nr_events++] = disk_uevents[i];
1647
1648 if (nr_events)
1649 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1650}
1651
1652/*
1653 * A disk events enabled device has the following sysfs nodes under
1654 * its /sys/block/X/ directory.
1655 *
1656 * events : list of all supported events
1657 * events_async : list of events which can be detected w/o polling
1658 * events_poll_msecs : polling interval, 0: disable, -1: system default
1659 */
1660static ssize_t __disk_events_show(unsigned int events, char *buf)
1661{
1662 const char *delim = "";
1663 ssize_t pos = 0;
1664 int i;
1665
1666 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1667 if (events & (1 << i)) {
1668 pos += sprintf(buf + pos, "%s%s",
1669 delim, disk_events_strs[i]);
1670 delim = " ";
1671 }
1672 if (pos)
1673 pos += sprintf(buf + pos, "\n");
1674 return pos;
1675}
1676
1677static ssize_t disk_events_show(struct device *dev,
1678 struct device_attribute *attr, char *buf)
1679{
1680 struct gendisk *disk = dev_to_disk(dev);
1681
1682 return __disk_events_show(disk->events, buf);
1683}
1684
1685static ssize_t disk_events_async_show(struct device *dev,
1686 struct device_attribute *attr, char *buf)
1687{
1688 struct gendisk *disk = dev_to_disk(dev);
1689
1690 return __disk_events_show(disk->async_events, buf);
1691}
1692
1693static ssize_t disk_events_poll_msecs_show(struct device *dev,
1694 struct device_attribute *attr,
1695 char *buf)
1696{
1697 struct gendisk *disk = dev_to_disk(dev);
1698
1699 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
1700}
1701
1702static ssize_t disk_events_poll_msecs_store(struct device *dev,
1703 struct device_attribute *attr,
1704 const char *buf, size_t count)
1705{
1706 struct gendisk *disk = dev_to_disk(dev);
1707 long intv;
1708
1709 if (!count || !sscanf(buf, "%ld", &intv))
1710 return -EINVAL;
1711
1712 if (intv < 0 && intv != -1)
1713 return -EINVAL;
1714
c3af54af 1715 disk_block_events(disk);
77ea887e
TH
1716 disk->ev->poll_msecs = intv;
1717 __disk_unblock_events(disk, true);
1718
1719 return count;
1720}
1721
1722static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
1723static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
1724static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
1725 disk_events_poll_msecs_show,
1726 disk_events_poll_msecs_store);
1727
1728static const struct attribute *disk_events_attrs[] = {
1729 &dev_attr_events.attr,
1730 &dev_attr_events_async.attr,
1731 &dev_attr_events_poll_msecs.attr,
1732 NULL,
1733};
1734
1735/*
1736 * The default polling interval can be specified by the kernel
1737 * parameter block.events_dfl_poll_msecs which defaults to 0
1738 * (disable). This can also be modified runtime by writing to
1739 * /sys/module/block/events_dfl_poll_msecs.
1740 */
1741static int disk_events_set_dfl_poll_msecs(const char *val,
1742 const struct kernel_param *kp)
1743{
1744 struct disk_events *ev;
1745 int ret;
1746
1747 ret = param_set_ulong(val, kp);
1748 if (ret < 0)
1749 return ret;
1750
1751 mutex_lock(&disk_events_mutex);
1752
1753 list_for_each_entry(ev, &disk_events, node)
85ef06d1 1754 disk_flush_events(ev->disk, 0);
77ea887e
TH
1755
1756 mutex_unlock(&disk_events_mutex);
1757
1758 return 0;
1759}
1760
1761static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
1762 .set = disk_events_set_dfl_poll_msecs,
1763 .get = param_get_ulong,
1764};
1765
1766#undef MODULE_PARAM_PREFIX
1767#define MODULE_PARAM_PREFIX "block."
1768
1769module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
1770 &disk_events_dfl_poll_msecs, 0644);
1771
1772/*
9f53d2fe 1773 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
77ea887e 1774 */
9f53d2fe 1775static void disk_alloc_events(struct gendisk *disk)
77ea887e
TH
1776{
1777 struct disk_events *ev;
1778
75e3f3ee 1779 if (!disk->fops->check_events)
77ea887e
TH
1780 return;
1781
1782 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1783 if (!ev) {
1784 pr_warn("%s: failed to initialize events\n", disk->disk_name);
1785 return;
1786 }
1787
77ea887e
TH
1788 INIT_LIST_HEAD(&ev->node);
1789 ev->disk = disk;
1790 spin_lock_init(&ev->lock);
fdd514e1 1791 mutex_init(&ev->block_mutex);
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TH
1792 ev->block = 1;
1793 ev->poll_msecs = -1;
1794 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
1795
9f53d2fe
SG
1796 disk->ev = ev;
1797}
1798
1799static void disk_add_events(struct gendisk *disk)
1800{
1801 if (!disk->ev)
1802 return;
1803
1804 /* FIXME: error handling */
1805 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
1806 pr_warn("%s: failed to create sysfs files for events\n",
1807 disk->disk_name);
1808
77ea887e 1809 mutex_lock(&disk_events_mutex);
9f53d2fe 1810 list_add_tail(&disk->ev->node, &disk_events);
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TH
1811 mutex_unlock(&disk_events_mutex);
1812
1813 /*
1814 * Block count is initialized to 1 and the following initial
1815 * unblock kicks it into action.
1816 */
1817 __disk_unblock_events(disk, true);
1818}
1819
1820static void disk_del_events(struct gendisk *disk)
1821{
1822 if (!disk->ev)
1823 return;
1824
c3af54af 1825 disk_block_events(disk);
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TH
1826
1827 mutex_lock(&disk_events_mutex);
1828 list_del_init(&disk->ev->node);
1829 mutex_unlock(&disk_events_mutex);
1830
1831 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
1832}
1833
1834static void disk_release_events(struct gendisk *disk)
1835{
1836 /* the block count should be 1 from disk_del_events() */
1837 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
1838 kfree(disk->ev);
1839}