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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>
66114cad 11#include <linux/backing-dev.h>
1da177e4
LT
12#include <linux/init.h>
13#include <linux/spinlock.h>
f500975a 14#include <linux/proc_fs.h>
1da177e4
LT
15#include <linux/seq_file.h>
16#include <linux/slab.h>
17#include <linux/kmod.h>
18#include <linux/kobj_map.h>
58383af6 19#include <linux/mutex.h>
bcce3de1 20#include <linux/idr.h>
77ea887e 21#include <linux/log2.h>
25e823c8 22#include <linux/pm_runtime.h>
1da177e4 23
ff88972c
AB
24#include "blk.h"
25
edfaa7c3 26static DEFINE_MUTEX(block_class_lock);
edfaa7c3 27struct kobject *block_depr;
1da177e4 28
bcce3de1 29/* for extended dynamic devt allocation, currently only one major is used */
ce23bba8 30#define NR_EXT_DEVT (1 << MINORBITS)
bcce3de1 31
2da78092 32/* For extended devt allocation. ext_devt_lock prevents look up
bcce3de1
TH
33 * results from going away underneath its user.
34 */
2da78092 35static DEFINE_SPINLOCK(ext_devt_lock);
bcce3de1
TH
36static DEFINE_IDR(ext_devt_idr);
37
1826eadf
AB
38static struct device_type disk_type;
39
12c2bdb2
DB
40static void disk_check_events(struct disk_events *ev,
41 unsigned int *clearing_ptr);
9f53d2fe 42static void disk_alloc_events(struct gendisk *disk);
77ea887e
TH
43static void disk_add_events(struct gendisk *disk);
44static void disk_del_events(struct gendisk *disk);
45static void disk_release_events(struct gendisk *disk);
46
e71bf0d0
TH
47/**
48 * disk_get_part - get partition
49 * @disk: disk to look partition from
50 * @partno: partition number
51 *
52 * Look for partition @partno from @disk. If found, increment
53 * reference count and return it.
54 *
55 * CONTEXT:
56 * Don't care.
57 *
58 * RETURNS:
59 * Pointer to the found partition on success, NULL if not found.
60 */
61struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
62{
540eed56
TH
63 struct hd_struct *part = NULL;
64 struct disk_part_tbl *ptbl;
e71bf0d0 65
540eed56 66 if (unlikely(partno < 0))
e71bf0d0 67 return NULL;
540eed56 68
e71bf0d0 69 rcu_read_lock();
540eed56
TH
70
71 ptbl = rcu_dereference(disk->part_tbl);
72 if (likely(partno < ptbl->len)) {
73 part = rcu_dereference(ptbl->part[partno]);
74 if (part)
75 get_device(part_to_dev(part));
76 }
77
e71bf0d0
TH
78 rcu_read_unlock();
79
80 return part;
81}
82EXPORT_SYMBOL_GPL(disk_get_part);
83
84/**
85 * disk_part_iter_init - initialize partition iterator
86 * @piter: iterator to initialize
87 * @disk: disk to iterate over
88 * @flags: DISK_PITER_* flags
89 *
90 * Initialize @piter so that it iterates over partitions of @disk.
91 *
92 * CONTEXT:
93 * Don't care.
94 */
95void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
96 unsigned int flags)
97{
540eed56
TH
98 struct disk_part_tbl *ptbl;
99
100 rcu_read_lock();
101 ptbl = rcu_dereference(disk->part_tbl);
102
e71bf0d0
TH
103 piter->disk = disk;
104 piter->part = NULL;
105
106 if (flags & DISK_PITER_REVERSE)
540eed56 107 piter->idx = ptbl->len - 1;
71982a40 108 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
e71bf0d0 109 piter->idx = 0;
b5d0b9df
TH
110 else
111 piter->idx = 1;
e71bf0d0
TH
112
113 piter->flags = flags;
540eed56
TH
114
115 rcu_read_unlock();
e71bf0d0
TH
116}
117EXPORT_SYMBOL_GPL(disk_part_iter_init);
118
119/**
120 * disk_part_iter_next - proceed iterator to the next partition and return it
121 * @piter: iterator of interest
122 *
123 * Proceed @piter to the next partition and return it.
124 *
125 * CONTEXT:
126 * Don't care.
127 */
128struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
129{
540eed56 130 struct disk_part_tbl *ptbl;
e71bf0d0
TH
131 int inc, end;
132
133 /* put the last partition */
134 disk_put_part(piter->part);
135 piter->part = NULL;
136
540eed56 137 /* get part_tbl */
e71bf0d0 138 rcu_read_lock();
540eed56 139 ptbl = rcu_dereference(piter->disk->part_tbl);
e71bf0d0
TH
140
141 /* determine iteration parameters */
142 if (piter->flags & DISK_PITER_REVERSE) {
143 inc = -1;
71982a40
TH
144 if (piter->flags & (DISK_PITER_INCL_PART0 |
145 DISK_PITER_INCL_EMPTY_PART0))
b5d0b9df
TH
146 end = -1;
147 else
148 end = 0;
e71bf0d0
TH
149 } else {
150 inc = 1;
540eed56 151 end = ptbl->len;
e71bf0d0
TH
152 }
153
154 /* iterate to the next partition */
155 for (; piter->idx != end; piter->idx += inc) {
156 struct hd_struct *part;
157
540eed56 158 part = rcu_dereference(ptbl->part[piter->idx]);
e71bf0d0
TH
159 if (!part)
160 continue;
c83f6bf9 161 if (!part_nr_sects_read(part) &&
71982a40
TH
162 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
163 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
164 piter->idx == 0))
e71bf0d0
TH
165 continue;
166
ed9e1982 167 get_device(part_to_dev(part));
e71bf0d0
TH
168 piter->part = part;
169 piter->idx += inc;
170 break;
171 }
172
173 rcu_read_unlock();
174
175 return piter->part;
176}
177EXPORT_SYMBOL_GPL(disk_part_iter_next);
178
179/**
180 * disk_part_iter_exit - finish up partition iteration
181 * @piter: iter of interest
182 *
183 * Called when iteration is over. Cleans up @piter.
184 *
185 * CONTEXT:
186 * Don't care.
187 */
188void disk_part_iter_exit(struct disk_part_iter *piter)
189{
190 disk_put_part(piter->part);
191 piter->part = NULL;
192}
193EXPORT_SYMBOL_GPL(disk_part_iter_exit);
194
a6f23657
JA
195static inline int sector_in_part(struct hd_struct *part, sector_t sector)
196{
197 return part->start_sect <= sector &&
c83f6bf9 198 sector < part->start_sect + part_nr_sects_read(part);
a6f23657
JA
199}
200
e71bf0d0
TH
201/**
202 * disk_map_sector_rcu - map sector to partition
203 * @disk: gendisk of interest
204 * @sector: sector to map
205 *
206 * Find out which partition @sector maps to on @disk. This is
207 * primarily used for stats accounting.
208 *
209 * CONTEXT:
210 * RCU read locked. The returned partition pointer is valid only
211 * while preemption is disabled.
212 *
213 * RETURNS:
074a7aca 214 * Found partition on success, part0 is returned if no partition matches
e71bf0d0
TH
215 */
216struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
217{
540eed56 218 struct disk_part_tbl *ptbl;
a6f23657 219 struct hd_struct *part;
e71bf0d0
TH
220 int i;
221
540eed56
TH
222 ptbl = rcu_dereference(disk->part_tbl);
223
a6f23657
JA
224 part = rcu_dereference(ptbl->last_lookup);
225 if (part && sector_in_part(part, sector))
226 return part;
227
540eed56 228 for (i = 1; i < ptbl->len; i++) {
a6f23657 229 part = rcu_dereference(ptbl->part[i]);
e71bf0d0 230
a6f23657
JA
231 if (part && sector_in_part(part, sector)) {
232 rcu_assign_pointer(ptbl->last_lookup, part);
e71bf0d0 233 return part;
a6f23657 234 }
e71bf0d0 235 }
074a7aca 236 return &disk->part0;
e71bf0d0
TH
237}
238EXPORT_SYMBOL_GPL(disk_map_sector_rcu);
239
1da177e4
LT
240/*
241 * Can be deleted altogether. Later.
242 *
243 */
244static struct blk_major_name {
245 struct blk_major_name *next;
246 int major;
247 char name[16];
68eef3b4 248} *major_names[BLKDEV_MAJOR_HASH_SIZE];
1da177e4
LT
249
250/* index in the above - for now: assume no multimajor ranges */
e61eb2e9 251static inline int major_to_index(unsigned major)
1da177e4 252{
68eef3b4 253 return major % BLKDEV_MAJOR_HASH_SIZE;
7170be5f
NH
254}
255
68eef3b4 256#ifdef CONFIG_PROC_FS
cf771cb5 257void blkdev_show(struct seq_file *seqf, off_t offset)
7170be5f 258{
68eef3b4 259 struct blk_major_name *dp;
7170be5f 260
68eef3b4 261 if (offset < BLKDEV_MAJOR_HASH_SIZE) {
edfaa7c3 262 mutex_lock(&block_class_lock);
68eef3b4 263 for (dp = major_names[offset]; dp; dp = dp->next)
cf771cb5 264 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
edfaa7c3 265 mutex_unlock(&block_class_lock);
1da177e4 266 }
1da177e4 267}
68eef3b4 268#endif /* CONFIG_PROC_FS */
1da177e4 269
9e8c0bcc
MN
270/**
271 * register_blkdev - register a new block device
272 *
273 * @major: the requested major device number [1..255]. If @major=0, try to
274 * allocate any unused major number.
275 * @name: the name of the new block device as a zero terminated string
276 *
277 * The @name must be unique within the system.
278 *
279 * The return value depends on the @major input parameter.
280 * - if a major device number was requested in range [1..255] then the
281 * function returns zero on success, or a negative error code
282 * - if any unused major number was requested with @major=0 parameter
283 * then the return value is the allocated major number in range
284 * [1..255] or a negative error code otherwise
285 */
1da177e4
LT
286int register_blkdev(unsigned int major, const char *name)
287{
288 struct blk_major_name **n, *p;
289 int index, ret = 0;
290
edfaa7c3 291 mutex_lock(&block_class_lock);
1da177e4
LT
292
293 /* temporary */
294 if (major == 0) {
295 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
296 if (major_names[index] == NULL)
297 break;
298 }
299
300 if (index == 0) {
301 printk("register_blkdev: failed to get major for %s\n",
302 name);
303 ret = -EBUSY;
304 goto out;
305 }
306 major = index;
307 ret = major;
308 }
309
310 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
311 if (p == NULL) {
312 ret = -ENOMEM;
313 goto out;
314 }
315
316 p->major = major;
317 strlcpy(p->name, name, sizeof(p->name));
318 p->next = NULL;
319 index = major_to_index(major);
320
321 for (n = &major_names[index]; *n; n = &(*n)->next) {
322 if ((*n)->major == major)
323 break;
324 }
325 if (!*n)
326 *n = p;
327 else
328 ret = -EBUSY;
329
330 if (ret < 0) {
331 printk("register_blkdev: cannot get major %d for %s\n",
332 major, name);
333 kfree(p);
334 }
335out:
edfaa7c3 336 mutex_unlock(&block_class_lock);
1da177e4
LT
337 return ret;
338}
339
340EXPORT_SYMBOL(register_blkdev);
341
f4480240 342void unregister_blkdev(unsigned int major, const char *name)
1da177e4
LT
343{
344 struct blk_major_name **n;
345 struct blk_major_name *p = NULL;
346 int index = major_to_index(major);
1da177e4 347
edfaa7c3 348 mutex_lock(&block_class_lock);
1da177e4
LT
349 for (n = &major_names[index]; *n; n = &(*n)->next)
350 if ((*n)->major == major)
351 break;
294462a5
AM
352 if (!*n || strcmp((*n)->name, name)) {
353 WARN_ON(1);
294462a5 354 } else {
1da177e4
LT
355 p = *n;
356 *n = p->next;
357 }
edfaa7c3 358 mutex_unlock(&block_class_lock);
1da177e4 359 kfree(p);
1da177e4
LT
360}
361
362EXPORT_SYMBOL(unregister_blkdev);
363
364static struct kobj_map *bdev_map;
365
870d6656
TH
366/**
367 * blk_mangle_minor - scatter minor numbers apart
368 * @minor: minor number to mangle
369 *
370 * Scatter consecutively allocated @minor number apart if MANGLE_DEVT
371 * is enabled. Mangling twice gives the original value.
372 *
373 * RETURNS:
374 * Mangled value.
375 *
376 * CONTEXT:
377 * Don't care.
378 */
379static int blk_mangle_minor(int minor)
380{
381#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
382 int i;
383
384 for (i = 0; i < MINORBITS / 2; i++) {
385 int low = minor & (1 << i);
386 int high = minor & (1 << (MINORBITS - 1 - i));
387 int distance = MINORBITS - 1 - 2 * i;
388
389 minor ^= low | high; /* clear both bits */
390 low <<= distance; /* swap the positions */
391 high >>= distance;
392 minor |= low | high; /* and set */
393 }
394#endif
395 return minor;
396}
397
bcce3de1
TH
398/**
399 * blk_alloc_devt - allocate a dev_t for a partition
400 * @part: partition to allocate dev_t for
bcce3de1
TH
401 * @devt: out parameter for resulting dev_t
402 *
403 * Allocate a dev_t for block device.
404 *
405 * RETURNS:
406 * 0 on success, allocated dev_t is returned in *@devt. -errno on
407 * failure.
408 *
409 * CONTEXT:
410 * Might sleep.
411 */
412int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
413{
414 struct gendisk *disk = part_to_disk(part);
bab998d6 415 int idx;
bcce3de1
TH
416
417 /* in consecutive minor range? */
418 if (part->partno < disk->minors) {
419 *devt = MKDEV(disk->major, disk->first_minor + part->partno);
420 return 0;
421 }
422
423 /* allocate ext devt */
2da78092
KB
424 idr_preload(GFP_KERNEL);
425
4d66e5e9 426 spin_lock_bh(&ext_devt_lock);
2da78092 427 idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
4d66e5e9 428 spin_unlock_bh(&ext_devt_lock);
2da78092
KB
429
430 idr_preload_end();
bab998d6
TH
431 if (idx < 0)
432 return idx == -ENOSPC ? -EBUSY : idx;
bcce3de1 433
870d6656 434 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
bcce3de1
TH
435 return 0;
436}
437
438/**
439 * blk_free_devt - free a dev_t
440 * @devt: dev_t to free
441 *
442 * Free @devt which was allocated using blk_alloc_devt().
443 *
444 * CONTEXT:
445 * Might sleep.
446 */
447void blk_free_devt(dev_t devt)
448{
bcce3de1
TH
449 if (devt == MKDEV(0, 0))
450 return;
451
452 if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
4d66e5e9 453 spin_lock_bh(&ext_devt_lock);
870d6656 454 idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
4d66e5e9 455 spin_unlock_bh(&ext_devt_lock);
bcce3de1
TH
456 }
457}
458
1f014290
TH
459static char *bdevt_str(dev_t devt, char *buf)
460{
461 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
462 char tbuf[BDEVT_SIZE];
463 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
464 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
465 } else
466 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
467
468 return buf;
469}
470
1da177e4
LT
471/*
472 * Register device numbers dev..(dev+range-1)
473 * range must be nonzero
474 * The hash chain is sorted on range, so that subranges can override.
475 */
edfaa7c3 476void blk_register_region(dev_t devt, unsigned long range, struct module *module,
1da177e4
LT
477 struct kobject *(*probe)(dev_t, int *, void *),
478 int (*lock)(dev_t, void *), void *data)
479{
edfaa7c3 480 kobj_map(bdev_map, devt, range, module, probe, lock, data);
1da177e4
LT
481}
482
483EXPORT_SYMBOL(blk_register_region);
484
edfaa7c3 485void blk_unregister_region(dev_t devt, unsigned long range)
1da177e4 486{
edfaa7c3 487 kobj_unmap(bdev_map, devt, range);
1da177e4
LT
488}
489
490EXPORT_SYMBOL(blk_unregister_region);
491
cf771cb5 492static struct kobject *exact_match(dev_t devt, int *partno, void *data)
1da177e4
LT
493{
494 struct gendisk *p = data;
edfaa7c3 495
ed9e1982 496 return &disk_to_dev(p)->kobj;
1da177e4
LT
497}
498
edfaa7c3 499static int exact_lock(dev_t devt, void *data)
1da177e4
LT
500{
501 struct gendisk *p = data;
502
503 if (!get_disk(p))
504 return -1;
505 return 0;
506}
507
4752bc30 508static void register_disk(struct gendisk *disk)
d2bf1b67
TH
509{
510 struct device *ddev = disk_to_dev(disk);
511 struct block_device *bdev;
512 struct disk_part_iter piter;
513 struct hd_struct *part;
514 int err;
515
516 ddev->parent = disk->driverfs_dev;
517
ffc8b308 518 dev_set_name(ddev, "%s", disk->disk_name);
d2bf1b67
TH
519
520 /* delay uevents, until we scanned partition table */
521 dev_set_uevent_suppress(ddev, 1);
522
523 if (device_add(ddev))
524 return;
525 if (!sysfs_deprecated) {
526 err = sysfs_create_link(block_depr, &ddev->kobj,
527 kobject_name(&ddev->kobj));
528 if (err) {
529 device_del(ddev);
530 return;
531 }
532 }
25e823c8
ML
533
534 /*
535 * avoid probable deadlock caused by allocating memory with
536 * GFP_KERNEL in runtime_resume callback of its all ancestor
537 * devices
538 */
539 pm_runtime_set_memalloc_noio(ddev, true);
540
d2bf1b67
TH
541 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
542 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
543
544 /* No minors to use for partitions */
d27769ec 545 if (!disk_part_scan_enabled(disk))
d2bf1b67
TH
546 goto exit;
547
548 /* No such device (e.g., media were just removed) */
549 if (!get_capacity(disk))
550 goto exit;
551
552 bdev = bdget_disk(disk, 0);
553 if (!bdev)
554 goto exit;
555
556 bdev->bd_invalidated = 1;
557 err = blkdev_get(bdev, FMODE_READ, NULL);
558 if (err < 0)
559 goto exit;
560 blkdev_put(bdev, FMODE_READ);
561
562exit:
563 /* announce disk after possible partitions are created */
564 dev_set_uevent_suppress(ddev, 0);
565 kobject_uevent(&ddev->kobj, KOBJ_ADD);
566
567 /* announce possible partitions */
568 disk_part_iter_init(&piter, disk, 0);
569 while ((part = disk_part_iter_next(&piter)))
570 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
571 disk_part_iter_exit(&piter);
572}
573
1da177e4
LT
574/**
575 * add_disk - add partitioning information to kernel list
576 * @disk: per-device partitioning information
577 *
578 * This function registers the partitioning information in @disk
579 * with the kernel.
3e1a7ff8
TH
580 *
581 * FIXME: error handling
1da177e4
LT
582 */
583void add_disk(struct gendisk *disk)
584{
cf0ca9fe 585 struct backing_dev_info *bdi;
3e1a7ff8 586 dev_t devt;
6ffeea77 587 int retval;
cf0ca9fe 588
3e1a7ff8
TH
589 /* minors == 0 indicates to use ext devt from part0 and should
590 * be accompanied with EXT_DEVT flag. Make sure all
591 * parameters make sense.
592 */
593 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
594 WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT));
595
1da177e4 596 disk->flags |= GENHD_FL_UP;
3e1a7ff8
TH
597
598 retval = blk_alloc_devt(&disk->part0, &devt);
599 if (retval) {
600 WARN_ON(1);
601 return;
602 }
603 disk_to_dev(disk)->devt = devt;
604
605 /* ->major and ->first_minor aren't supposed to be
606 * dereferenced from here on, but set them just in case.
607 */
608 disk->major = MAJOR(devt);
609 disk->first_minor = MINOR(devt);
610
9f53d2fe
SG
611 disk_alloc_events(disk);
612
9f5e4865 613 /* Register BDI before referencing it from bdev */
01ea5063
SJK
614 bdi = &disk->queue->backing_dev_info;
615 bdi_register_dev(bdi, disk_devt(disk));
616
f331c029
TH
617 blk_register_region(disk_devt(disk), disk->minors, NULL,
618 exact_match, exact_lock, disk);
1da177e4
LT
619 register_disk(disk);
620 blk_register_queue(disk);
cf0ca9fe 621
523e1d39
TH
622 /*
623 * Take an extra ref on queue which will be put on disk_release()
624 * so that it sticks around as long as @disk is there.
625 */
09ac46c4 626 WARN_ON_ONCE(!blk_get_queue(disk->queue));
523e1d39 627
ed9e1982
TH
628 retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj,
629 "bdi");
6ffeea77 630 WARN_ON(retval);
1da177e4 631
77ea887e 632 disk_add_events(disk);
1da177e4 633}
1da177e4 634EXPORT_SYMBOL(add_disk);
1da177e4 635
d2bf1b67 636void del_gendisk(struct gendisk *disk)
1da177e4 637{
d2bf1b67
TH
638 struct disk_part_iter piter;
639 struct hd_struct *part;
640
77ea887e
TH
641 disk_del_events(disk);
642
d2bf1b67
TH
643 /* invalidate stuff */
644 disk_part_iter_init(&piter, disk,
645 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
646 while ((part = disk_part_iter_next(&piter))) {
647 invalidate_partition(disk, part->partno);
648 delete_partition(disk, part->partno);
649 }
650 disk_part_iter_exit(&piter);
651
652 invalidate_partition(disk, 0);
d2bf1b67
TH
653 set_capacity(disk, 0);
654 disk->flags &= ~GENHD_FL_UP;
655
ed9e1982 656 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
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
4d66e5e9 694 spin_lock_bh(&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 }
4d66e5e9 700 spin_unlock_bh(&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;
5fabcb4c 1073 int i, target;
540eed56 1074 size_t size;
5fabcb4c
JA
1075
1076 /*
1077 * check for int overflow, since we can get here from blkpg_ioctl()
1078 * with a user passed 'partno'.
1079 */
1080 target = partno + 1;
1081 if (target < 0)
1082 return -EINVAL;
540eed56
TH
1083
1084 /* disk_max_parts() is zero during initialization, ignore if so */
1085 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1086 return -EINVAL;
1087
1088 if (target <= len)
1089 return 0;
1090
1091 size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]);
1092 new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id);
1093 if (!new_ptbl)
1094 return -ENOMEM;
1095
540eed56
TH
1096 new_ptbl->len = target;
1097
1098 for (i = 0; i < len; i++)
1099 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1100
1101 disk_replace_part_tbl(disk, new_ptbl);
1102 return 0;
1103}
1104
edfaa7c3 1105static void disk_release(struct device *dev)
1da177e4 1106{
edfaa7c3
KS
1107 struct gendisk *disk = dev_to_disk(dev);
1108
2da78092 1109 blk_free_devt(dev->devt);
77ea887e 1110 disk_release_events(disk);
1da177e4 1111 kfree(disk->random);
540eed56 1112 disk_replace_part_tbl(disk, NULL);
074a7aca 1113 free_part_stats(&disk->part0);
6d1d8050 1114 free_part_info(&disk->part0);
523e1d39
TH
1115 if (disk->queue)
1116 blk_put_queue(disk->queue);
1da177e4
LT
1117 kfree(disk);
1118}
edfaa7c3
KS
1119struct class block_class = {
1120 .name = "block",
1da177e4
LT
1121};
1122
3c2670e6 1123static char *block_devnode(struct device *dev, umode_t *mode,
4e4098a3 1124 kuid_t *uid, kgid_t *gid)
b03f38b6
KS
1125{
1126 struct gendisk *disk = dev_to_disk(dev);
1127
e454cea2
KS
1128 if (disk->devnode)
1129 return disk->devnode(disk, mode);
b03f38b6
KS
1130 return NULL;
1131}
1132
1826eadf 1133static struct device_type disk_type = {
edfaa7c3
KS
1134 .name = "disk",
1135 .groups = disk_attr_groups,
1136 .release = disk_release,
e454cea2 1137 .devnode = block_devnode,
1da177e4
LT
1138};
1139
a6e2ba88 1140#ifdef CONFIG_PROC_FS
cf771cb5
TH
1141/*
1142 * aggregate disk stat collector. Uses the same stats that the sysfs
1143 * entries do, above, but makes them available through one seq_file.
1144 *
1145 * The output looks suspiciously like /proc/partitions with a bunch of
1146 * extra fields.
1147 */
1148static int diskstats_show(struct seq_file *seqf, void *v)
1da177e4
LT
1149{
1150 struct gendisk *gp = v;
e71bf0d0
TH
1151 struct disk_part_iter piter;
1152 struct hd_struct *hd;
1da177e4 1153 char buf[BDEVNAME_SIZE];
c9959059 1154 int cpu;
1da177e4
LT
1155
1156 /*
ed9e1982 1157 if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next)
cf771cb5 1158 seq_puts(seqf, "major minor name"
1da177e4
LT
1159 " rio rmerge rsect ruse wio wmerge "
1160 "wsect wuse running use aveq"
1161 "\n\n");
1162 */
9f5e4865 1163
71982a40 1164 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
e71bf0d0 1165 while ((hd = disk_part_iter_next(&piter))) {
074a7aca 1166 cpu = part_stat_lock();
c9959059 1167 part_round_stats(cpu, hd);
074a7aca 1168 part_stat_unlock();
f95fe9cf
HP
1169 seq_printf(seqf, "%4d %7d %s %lu %lu %lu "
1170 "%u %lu %lu %lu %u %u %u %u\n",
f331c029
TH
1171 MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
1172 disk_name(gp, hd->partno, buf),
53f22956
LY
1173 part_stat_read(hd, ios[READ]),
1174 part_stat_read(hd, merges[READ]),
f95fe9cf 1175 part_stat_read(hd, sectors[READ]),
53f22956
LY
1176 jiffies_to_msecs(part_stat_read(hd, ticks[READ])),
1177 part_stat_read(hd, ios[WRITE]),
1178 part_stat_read(hd, merges[WRITE]),
f95fe9cf 1179 part_stat_read(hd, sectors[WRITE]),
53f22956 1180 jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])),
316d315b 1181 part_in_flight(hd),
28f39d55
JM
1182 jiffies_to_msecs(part_stat_read(hd, io_ticks)),
1183 jiffies_to_msecs(part_stat_read(hd, time_in_queue))
1184 );
1da177e4 1185 }
e71bf0d0 1186 disk_part_iter_exit(&piter);
9f5e4865 1187
1da177e4
LT
1188 return 0;
1189}
1190
31d85ab2 1191static const struct seq_operations diskstats_op = {
def4e38d
TH
1192 .start = disk_seqf_start,
1193 .next = disk_seqf_next,
1194 .stop = disk_seqf_stop,
1da177e4
LT
1195 .show = diskstats_show
1196};
f500975a 1197
31d85ab2
AD
1198static int diskstats_open(struct inode *inode, struct file *file)
1199{
1200 return seq_open(file, &diskstats_op);
1201}
1202
1203static const struct file_operations proc_diskstats_operations = {
1204 .open = diskstats_open,
1205 .read = seq_read,
1206 .llseek = seq_lseek,
1207 .release = seq_release,
1208};
1209
f500975a
AD
1210static int __init proc_genhd_init(void)
1211{
31d85ab2 1212 proc_create("diskstats", 0, NULL, &proc_diskstats_operations);
f500975a
AD
1213 proc_create("partitions", 0, NULL, &proc_partitions_operations);
1214 return 0;
1215}
1216module_init(proc_genhd_init);
a6e2ba88 1217#endif /* CONFIG_PROC_FS */
1da177e4 1218
cf771cb5 1219dev_t blk_lookup_devt(const char *name, int partno)
a142be85 1220{
def4e38d
TH
1221 dev_t devt = MKDEV(0, 0);
1222 struct class_dev_iter iter;
1223 struct device *dev;
a142be85 1224
def4e38d
TH
1225 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1226 while ((dev = class_dev_iter_next(&iter))) {
a142be85 1227 struct gendisk *disk = dev_to_disk(dev);
548b10eb 1228 struct hd_struct *part;
a142be85 1229
3ada8b7e 1230 if (strcmp(dev_name(dev), name))
f331c029 1231 continue;
f331c029 1232
41b8c853
NB
1233 if (partno < disk->minors) {
1234 /* We need to return the right devno, even
1235 * if the partition doesn't exist yet.
1236 */
1237 devt = MKDEV(MAJOR(dev->devt),
1238 MINOR(dev->devt) + partno);
1239 break;
1240 }
548b10eb 1241 part = disk_get_part(disk, partno);
2bbedcb4 1242 if (part) {
f331c029 1243 devt = part_devt(part);
e71bf0d0 1244 disk_put_part(part);
548b10eb 1245 break;
def4e38d 1246 }
548b10eb 1247 disk_put_part(part);
5c0ef6d0 1248 }
def4e38d 1249 class_dev_iter_exit(&iter);
edfaa7c3
KS
1250 return devt;
1251}
edfaa7c3
KS
1252EXPORT_SYMBOL(blk_lookup_devt);
1253
1da177e4
LT
1254struct gendisk *alloc_disk(int minors)
1255{
c304a51b 1256 return alloc_disk_node(minors, NUMA_NO_NODE);
1946089a 1257}
689d6fac 1258EXPORT_SYMBOL(alloc_disk);
1946089a
CL
1259
1260struct gendisk *alloc_disk_node(int minors, int node_id)
1261{
1262 struct gendisk *disk;
1263
c1b511eb 1264 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1da177e4 1265 if (disk) {
074a7aca 1266 if (!init_part_stats(&disk->part0)) {
1da177e4
LT
1267 kfree(disk);
1268 return NULL;
1269 }
bf91db18 1270 disk->node_id = node_id;
540eed56
TH
1271 if (disk_expand_part_tbl(disk, 0)) {
1272 free_part_stats(&disk->part0);
b5d0b9df
TH
1273 kfree(disk);
1274 return NULL;
1da177e4 1275 }
540eed56 1276 disk->part_tbl->part[0] = &disk->part0;
6c23a968 1277
c83f6bf9
VG
1278 /*
1279 * set_capacity() and get_capacity() currently don't use
1280 * seqcounter to read/update the part0->nr_sects. Still init
1281 * the counter as we can read the sectors in IO submission
1282 * patch using seqence counters.
1283 *
1284 * TODO: Ideally set_capacity() and get_capacity() should be
1285 * converted to make use of bd_mutex and sequence counters.
1286 */
1287 seqcount_init(&disk->part0.nr_sects_seq);
6c23a968 1288 hd_ref_init(&disk->part0);
b5d0b9df 1289
1da177e4 1290 disk->minors = minors;
1da177e4 1291 rand_initialize_disk(disk);
ed9e1982
TH
1292 disk_to_dev(disk)->class = &block_class;
1293 disk_to_dev(disk)->type = &disk_type;
1294 device_initialize(disk_to_dev(disk));
1da177e4
LT
1295 }
1296 return disk;
1297}
1946089a 1298EXPORT_SYMBOL(alloc_disk_node);
1da177e4
LT
1299
1300struct kobject *get_disk(struct gendisk *disk)
1301{
1302 struct module *owner;
1303 struct kobject *kobj;
1304
1305 if (!disk->fops)
1306 return NULL;
1307 owner = disk->fops->owner;
1308 if (owner && !try_module_get(owner))
1309 return NULL;
ed9e1982 1310 kobj = kobject_get(&disk_to_dev(disk)->kobj);
1da177e4
LT
1311 if (kobj == NULL) {
1312 module_put(owner);
1313 return NULL;
1314 }
1315 return kobj;
1316
1317}
1318
1319EXPORT_SYMBOL(get_disk);
1320
1321void put_disk(struct gendisk *disk)
1322{
1323 if (disk)
ed9e1982 1324 kobject_put(&disk_to_dev(disk)->kobj);
1da177e4
LT
1325}
1326
1327EXPORT_SYMBOL(put_disk);
1328
e3264a4d
HR
1329static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1330{
1331 char event[] = "DISK_RO=1";
1332 char *envp[] = { event, NULL };
1333
1334 if (!ro)
1335 event[8] = '0';
1336 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1337}
1338
1da177e4
LT
1339void set_device_ro(struct block_device *bdev, int flag)
1340{
b7db9956 1341 bdev->bd_part->policy = flag;
1da177e4
LT
1342}
1343
1344EXPORT_SYMBOL(set_device_ro);
1345
1346void set_disk_ro(struct gendisk *disk, int flag)
1347{
e71bf0d0
TH
1348 struct disk_part_iter piter;
1349 struct hd_struct *part;
1350
e3264a4d
HR
1351 if (disk->part0.policy != flag) {
1352 set_disk_ro_uevent(disk, flag);
1353 disk->part0.policy = flag;
1354 }
1355
1356 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
e71bf0d0
TH
1357 while ((part = disk_part_iter_next(&piter)))
1358 part->policy = flag;
1359 disk_part_iter_exit(&piter);
1da177e4
LT
1360}
1361
1362EXPORT_SYMBOL(set_disk_ro);
1363
1364int bdev_read_only(struct block_device *bdev)
1365{
1366 if (!bdev)
1367 return 0;
b7db9956 1368 return bdev->bd_part->policy;
1da177e4
LT
1369}
1370
1371EXPORT_SYMBOL(bdev_read_only);
1372
cf771cb5 1373int invalidate_partition(struct gendisk *disk, int partno)
1da177e4
LT
1374{
1375 int res = 0;
cf771cb5 1376 struct block_device *bdev = bdget_disk(disk, partno);
1da177e4 1377 if (bdev) {
2ef41634 1378 fsync_bdev(bdev);
93b270f7 1379 res = __invalidate_device(bdev, true);
1da177e4
LT
1380 bdput(bdev);
1381 }
1382 return res;
1383}
1384
1385EXPORT_SYMBOL(invalidate_partition);
77ea887e
TH
1386
1387/*
1388 * Disk events - monitor disk events like media change and eject request.
1389 */
1390struct disk_events {
1391 struct list_head node; /* all disk_event's */
1392 struct gendisk *disk; /* the associated disk */
1393 spinlock_t lock;
1394
fdd514e1 1395 struct mutex block_mutex; /* protects blocking */
77ea887e
TH
1396 int block; /* event blocking depth */
1397 unsigned int pending; /* events already sent out */
1398 unsigned int clearing; /* events being cleared */
1399
1400 long poll_msecs; /* interval, -1 for default */
1401 struct delayed_work dwork;
1402};
1403
1404static const char *disk_events_strs[] = {
1405 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1406 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1407};
1408
1409static char *disk_uevents[] = {
1410 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1411 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1412};
1413
1414/* list of all disk_events */
1415static DEFINE_MUTEX(disk_events_mutex);
1416static LIST_HEAD(disk_events);
1417
1418/* disable in-kernel polling by default */
1419static unsigned long disk_events_dfl_poll_msecs = 0;
1420
1421static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1422{
1423 struct disk_events *ev = disk->ev;
1424 long intv_msecs = 0;
1425
1426 /*
1427 * If device-specific poll interval is set, always use it. If
1428 * the default is being used, poll iff there are events which
1429 * can't be monitored asynchronously.
1430 */
1431 if (ev->poll_msecs >= 0)
1432 intv_msecs = ev->poll_msecs;
1433 else if (disk->events & ~disk->async_events)
1434 intv_msecs = disk_events_dfl_poll_msecs;
1435
1436 return msecs_to_jiffies(intv_msecs);
1437}
1438
c3af54af
TH
1439/**
1440 * disk_block_events - block and flush disk event checking
1441 * @disk: disk to block events for
1442 *
1443 * On return from this function, it is guaranteed that event checking
1444 * isn't in progress and won't happen until unblocked by
1445 * disk_unblock_events(). Events blocking is counted and the actual
1446 * unblocking happens after the matching number of unblocks are done.
1447 *
1448 * Note that this intentionally does not block event checking from
1449 * disk_clear_events().
1450 *
1451 * CONTEXT:
1452 * Might sleep.
1453 */
1454void disk_block_events(struct gendisk *disk)
77ea887e
TH
1455{
1456 struct disk_events *ev = disk->ev;
1457 unsigned long flags;
1458 bool cancel;
1459
c3af54af
TH
1460 if (!ev)
1461 return;
1462
fdd514e1
TH
1463 /*
1464 * Outer mutex ensures that the first blocker completes canceling
1465 * the event work before further blockers are allowed to finish.
1466 */
1467 mutex_lock(&ev->block_mutex);
1468
77ea887e
TH
1469 spin_lock_irqsave(&ev->lock, flags);
1470 cancel = !ev->block++;
1471 spin_unlock_irqrestore(&ev->lock, flags);
1472
c3af54af
TH
1473 if (cancel)
1474 cancel_delayed_work_sync(&disk->ev->dwork);
fdd514e1
TH
1475
1476 mutex_unlock(&ev->block_mutex);
77ea887e
TH
1477}
1478
1479static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1480{
1481 struct disk_events *ev = disk->ev;
1482 unsigned long intv;
1483 unsigned long flags;
1484
1485 spin_lock_irqsave(&ev->lock, flags);
1486
1487 if (WARN_ON_ONCE(ev->block <= 0))
1488 goto out_unlock;
1489
1490 if (--ev->block)
1491 goto out_unlock;
1492
1493 /*
1494 * Not exactly a latency critical operation, set poll timer
1495 * slack to 25% and kick event check.
1496 */
1497 intv = disk_events_poll_jiffies(disk);
1498 set_timer_slack(&ev->dwork.timer, intv / 4);
1499 if (check_now)
695588f9
VK
1500 queue_delayed_work(system_freezable_power_efficient_wq,
1501 &ev->dwork, 0);
77ea887e 1502 else if (intv)
695588f9
VK
1503 queue_delayed_work(system_freezable_power_efficient_wq,
1504 &ev->dwork, intv);
77ea887e
TH
1505out_unlock:
1506 spin_unlock_irqrestore(&ev->lock, flags);
1507}
1508
77ea887e
TH
1509/**
1510 * disk_unblock_events - unblock disk event checking
1511 * @disk: disk to unblock events for
1512 *
1513 * Undo disk_block_events(). When the block count reaches zero, it
1514 * starts events polling if configured.
1515 *
1516 * CONTEXT:
1517 * Don't care. Safe to call from irq context.
1518 */
1519void disk_unblock_events(struct gendisk *disk)
1520{
1521 if (disk->ev)
facc31dd 1522 __disk_unblock_events(disk, false);
77ea887e
TH
1523}
1524
1525/**
85ef06d1
TH
1526 * disk_flush_events - schedule immediate event checking and flushing
1527 * @disk: disk to check and flush events for
1528 * @mask: events to flush
77ea887e 1529 *
85ef06d1
TH
1530 * Schedule immediate event checking on @disk if not blocked. Events in
1531 * @mask are scheduled to be cleared from the driver. Note that this
1532 * doesn't clear the events from @disk->ev.
77ea887e
TH
1533 *
1534 * CONTEXT:
85ef06d1 1535 * If @mask is non-zero must be called with bdev->bd_mutex held.
77ea887e 1536 */
85ef06d1 1537void disk_flush_events(struct gendisk *disk, unsigned int mask)
77ea887e 1538{
a9dce2a3 1539 struct disk_events *ev = disk->ev;
a9dce2a3
TH
1540
1541 if (!ev)
1542 return;
1543
85ef06d1
TH
1544 spin_lock_irq(&ev->lock);
1545 ev->clearing |= mask;
41f63c53 1546 if (!ev->block)
695588f9
VK
1547 mod_delayed_work(system_freezable_power_efficient_wq,
1548 &ev->dwork, 0);
85ef06d1 1549 spin_unlock_irq(&ev->lock);
77ea887e 1550}
77ea887e
TH
1551
1552/**
1553 * disk_clear_events - synchronously check, clear and return pending events
1554 * @disk: disk to fetch and clear events from
da3dae54 1555 * @mask: mask of events to be fetched and cleared
77ea887e
TH
1556 *
1557 * Disk events are synchronously checked and pending events in @mask
1558 * are cleared and returned. This ignores the block count.
1559 *
1560 * CONTEXT:
1561 * Might sleep.
1562 */
1563unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
1564{
1565 const struct block_device_operations *bdops = disk->fops;
1566 struct disk_events *ev = disk->ev;
1567 unsigned int pending;
12c2bdb2 1568 unsigned int clearing = mask;
77ea887e
TH
1569
1570 if (!ev) {
1571 /* for drivers still using the old ->media_changed method */
1572 if ((mask & DISK_EVENT_MEDIA_CHANGE) &&
1573 bdops->media_changed && bdops->media_changed(disk))
1574 return DISK_EVENT_MEDIA_CHANGE;
1575 return 0;
1576 }
1577
12c2bdb2
DB
1578 disk_block_events(disk);
1579
1580 /*
1581 * store the union of mask and ev->clearing on the stack so that the
1582 * race with disk_flush_events does not cause ambiguity (ev->clearing
1583 * can still be modified even if events are blocked).
1584 */
77ea887e 1585 spin_lock_irq(&ev->lock);
12c2bdb2
DB
1586 clearing |= ev->clearing;
1587 ev->clearing = 0;
77ea887e
TH
1588 spin_unlock_irq(&ev->lock);
1589
12c2bdb2 1590 disk_check_events(ev, &clearing);
aea24a8b 1591 /*
12c2bdb2
DB
1592 * if ev->clearing is not 0, the disk_flush_events got called in the
1593 * middle of this function, so we want to run the workfn without delay.
aea24a8b 1594 */
12c2bdb2 1595 __disk_unblock_events(disk, ev->clearing ? true : false);
77ea887e
TH
1596
1597 /* then, fetch and clear pending events */
1598 spin_lock_irq(&ev->lock);
77ea887e
TH
1599 pending = ev->pending & mask;
1600 ev->pending &= ~mask;
1601 spin_unlock_irq(&ev->lock);
12c2bdb2 1602 WARN_ON_ONCE(clearing & mask);
77ea887e
TH
1603
1604 return pending;
1605}
1606
12c2bdb2
DB
1607/*
1608 * Separate this part out so that a different pointer for clearing_ptr can be
1609 * passed in for disk_clear_events.
1610 */
77ea887e
TH
1611static void disk_events_workfn(struct work_struct *work)
1612{
1613 struct delayed_work *dwork = to_delayed_work(work);
1614 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
12c2bdb2
DB
1615
1616 disk_check_events(ev, &ev->clearing);
1617}
1618
1619static void disk_check_events(struct disk_events *ev,
1620 unsigned int *clearing_ptr)
1621{
77ea887e
TH
1622 struct gendisk *disk = ev->disk;
1623 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
12c2bdb2 1624 unsigned int clearing = *clearing_ptr;
77ea887e
TH
1625 unsigned int events;
1626 unsigned long intv;
1627 int nr_events = 0, i;
1628
1629 /* check events */
1630 events = disk->fops->check_events(disk, clearing);
1631
1632 /* accumulate pending events and schedule next poll if necessary */
1633 spin_lock_irq(&ev->lock);
1634
1635 events &= ~ev->pending;
1636 ev->pending |= events;
12c2bdb2 1637 *clearing_ptr &= ~clearing;
77ea887e
TH
1638
1639 intv = disk_events_poll_jiffies(disk);
1640 if (!ev->block && intv)
695588f9
VK
1641 queue_delayed_work(system_freezable_power_efficient_wq,
1642 &ev->dwork, intv);
77ea887e
TH
1643
1644 spin_unlock_irq(&ev->lock);
1645
7c88a168
TH
1646 /*
1647 * Tell userland about new events. Only the events listed in
1648 * @disk->events are reported. Unlisted events are processed the
1649 * same internally but never get reported to userland.
1650 */
77ea887e 1651 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
7c88a168 1652 if (events & disk->events & (1 << i))
77ea887e
TH
1653 envp[nr_events++] = disk_uevents[i];
1654
1655 if (nr_events)
1656 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
1657}
1658
1659/*
1660 * A disk events enabled device has the following sysfs nodes under
1661 * its /sys/block/X/ directory.
1662 *
1663 * events : list of all supported events
1664 * events_async : list of events which can be detected w/o polling
1665 * events_poll_msecs : polling interval, 0: disable, -1: system default
1666 */
1667static ssize_t __disk_events_show(unsigned int events, char *buf)
1668{
1669 const char *delim = "";
1670 ssize_t pos = 0;
1671 int i;
1672
1673 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
1674 if (events & (1 << i)) {
1675 pos += sprintf(buf + pos, "%s%s",
1676 delim, disk_events_strs[i]);
1677 delim = " ";
1678 }
1679 if (pos)
1680 pos += sprintf(buf + pos, "\n");
1681 return pos;
1682}
1683
1684static ssize_t disk_events_show(struct device *dev,
1685 struct device_attribute *attr, char *buf)
1686{
1687 struct gendisk *disk = dev_to_disk(dev);
1688
1689 return __disk_events_show(disk->events, buf);
1690}
1691
1692static ssize_t disk_events_async_show(struct device *dev,
1693 struct device_attribute *attr, char *buf)
1694{
1695 struct gendisk *disk = dev_to_disk(dev);
1696
1697 return __disk_events_show(disk->async_events, buf);
1698}
1699
1700static ssize_t disk_events_poll_msecs_show(struct device *dev,
1701 struct device_attribute *attr,
1702 char *buf)
1703{
1704 struct gendisk *disk = dev_to_disk(dev);
1705
1706 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
1707}
1708
1709static ssize_t disk_events_poll_msecs_store(struct device *dev,
1710 struct device_attribute *attr,
1711 const char *buf, size_t count)
1712{
1713 struct gendisk *disk = dev_to_disk(dev);
1714 long intv;
1715
1716 if (!count || !sscanf(buf, "%ld", &intv))
1717 return -EINVAL;
1718
1719 if (intv < 0 && intv != -1)
1720 return -EINVAL;
1721
c3af54af 1722 disk_block_events(disk);
77ea887e
TH
1723 disk->ev->poll_msecs = intv;
1724 __disk_unblock_events(disk, true);
1725
1726 return count;
1727}
1728
1729static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL);
1730static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL);
1731static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR,
1732 disk_events_poll_msecs_show,
1733 disk_events_poll_msecs_store);
1734
1735static const struct attribute *disk_events_attrs[] = {
1736 &dev_attr_events.attr,
1737 &dev_attr_events_async.attr,
1738 &dev_attr_events_poll_msecs.attr,
1739 NULL,
1740};
1741
1742/*
1743 * The default polling interval can be specified by the kernel
1744 * parameter block.events_dfl_poll_msecs which defaults to 0
1745 * (disable). This can also be modified runtime by writing to
1746 * /sys/module/block/events_dfl_poll_msecs.
1747 */
1748static int disk_events_set_dfl_poll_msecs(const char *val,
1749 const struct kernel_param *kp)
1750{
1751 struct disk_events *ev;
1752 int ret;
1753
1754 ret = param_set_ulong(val, kp);
1755 if (ret < 0)
1756 return ret;
1757
1758 mutex_lock(&disk_events_mutex);
1759
1760 list_for_each_entry(ev, &disk_events, node)
85ef06d1 1761 disk_flush_events(ev->disk, 0);
77ea887e
TH
1762
1763 mutex_unlock(&disk_events_mutex);
1764
1765 return 0;
1766}
1767
1768static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
1769 .set = disk_events_set_dfl_poll_msecs,
1770 .get = param_get_ulong,
1771};
1772
1773#undef MODULE_PARAM_PREFIX
1774#define MODULE_PARAM_PREFIX "block."
1775
1776module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
1777 &disk_events_dfl_poll_msecs, 0644);
1778
1779/*
9f53d2fe 1780 * disk_{alloc|add|del|release}_events - initialize and destroy disk_events.
77ea887e 1781 */
9f53d2fe 1782static void disk_alloc_events(struct gendisk *disk)
77ea887e
TH
1783{
1784 struct disk_events *ev;
1785
75e3f3ee 1786 if (!disk->fops->check_events)
77ea887e
TH
1787 return;
1788
1789 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
1790 if (!ev) {
1791 pr_warn("%s: failed to initialize events\n", disk->disk_name);
1792 return;
1793 }
1794
77ea887e
TH
1795 INIT_LIST_HEAD(&ev->node);
1796 ev->disk = disk;
1797 spin_lock_init(&ev->lock);
fdd514e1 1798 mutex_init(&ev->block_mutex);
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TH
1799 ev->block = 1;
1800 ev->poll_msecs = -1;
1801 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
1802
9f53d2fe
SG
1803 disk->ev = ev;
1804}
1805
1806static void disk_add_events(struct gendisk *disk)
1807{
1808 if (!disk->ev)
1809 return;
1810
1811 /* FIXME: error handling */
1812 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
1813 pr_warn("%s: failed to create sysfs files for events\n",
1814 disk->disk_name);
1815
77ea887e 1816 mutex_lock(&disk_events_mutex);
9f53d2fe 1817 list_add_tail(&disk->ev->node, &disk_events);
77ea887e
TH
1818 mutex_unlock(&disk_events_mutex);
1819
1820 /*
1821 * Block count is initialized to 1 and the following initial
1822 * unblock kicks it into action.
1823 */
1824 __disk_unblock_events(disk, true);
1825}
1826
1827static void disk_del_events(struct gendisk *disk)
1828{
1829 if (!disk->ev)
1830 return;
1831
c3af54af 1832 disk_block_events(disk);
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TH
1833
1834 mutex_lock(&disk_events_mutex);
1835 list_del_init(&disk->ev->node);
1836 mutex_unlock(&disk_events_mutex);
1837
1838 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
1839}
1840
1841static void disk_release_events(struct gendisk *disk)
1842{
1843 /* the block count should be 1 from disk_del_events() */
1844 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
1845 kfree(disk->ev);
1846}