1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Copyright (C) 1991-1998 Linus Torvalds |
4 | * Re-organised Feb 1998 Russell King |
5 | * Copyright (C) 2020 Christoph Hellwig |
6 | */ |
7 | #include <linux/fs.h> |
8 | #include <linux/major.h> |
9 | #include <linux/slab.h> |
10 | #include <linux/ctype.h> |
11 | #include <linux/vmalloc.h> |
12 | #include <linux/raid/detect.h> |
13 | #include "check.h" |
14 | |
15 | static int (*const check_part[])(struct parsed_partitions *) = { |
16 | /* |
17 | * Probe partition formats with tables at disk address 0 |
18 | * that also have an ADFS boot block at 0xdc0. |
19 | */ |
20 | #ifdef CONFIG_ACORN_PARTITION_ICS |
21 | adfspart_check_ICS, |
22 | #endif |
23 | #ifdef CONFIG_ACORN_PARTITION_POWERTEC |
24 | adfspart_check_POWERTEC, |
25 | #endif |
26 | #ifdef CONFIG_ACORN_PARTITION_EESOX |
27 | adfspart_check_EESOX, |
28 | #endif |
29 | |
30 | /* |
31 | * Now move on to formats that only have partition info at |
32 | * disk address 0xdc0. Since these may also have stale |
33 | * PC/BIOS partition tables, they need to come before |
34 | * the msdos entry. |
35 | */ |
36 | #ifdef CONFIG_ACORN_PARTITION_CUMANA |
37 | adfspart_check_CUMANA, |
38 | #endif |
39 | #ifdef CONFIG_ACORN_PARTITION_ADFS |
40 | adfspart_check_ADFS, |
41 | #endif |
42 | |
43 | #ifdef CONFIG_CMDLINE_PARTITION |
44 | cmdline_partition, |
45 | #endif |
46 | #ifdef CONFIG_EFI_PARTITION |
47 | efi_partition, /* this must come before msdos */ |
48 | #endif |
49 | #ifdef CONFIG_SGI_PARTITION |
50 | sgi_partition, |
51 | #endif |
52 | #ifdef CONFIG_LDM_PARTITION |
53 | ldm_partition, /* this must come before msdos */ |
54 | #endif |
55 | #ifdef CONFIG_MSDOS_PARTITION |
56 | msdos_partition, |
57 | #endif |
58 | #ifdef CONFIG_OSF_PARTITION |
59 | osf_partition, |
60 | #endif |
61 | #ifdef CONFIG_SUN_PARTITION |
62 | sun_partition, |
63 | #endif |
64 | #ifdef CONFIG_AMIGA_PARTITION |
65 | amiga_partition, |
66 | #endif |
67 | #ifdef CONFIG_ATARI_PARTITION |
68 | atari_partition, |
69 | #endif |
70 | #ifdef CONFIG_MAC_PARTITION |
71 | mac_partition, |
72 | #endif |
73 | #ifdef CONFIG_ULTRIX_PARTITION |
74 | ultrix_partition, |
75 | #endif |
76 | #ifdef CONFIG_IBM_PARTITION |
77 | ibm_partition, |
78 | #endif |
79 | #ifdef CONFIG_KARMA_PARTITION |
80 | karma_partition, |
81 | #endif |
82 | #ifdef CONFIG_SYSV68_PARTITION |
83 | sysv68_partition, |
84 | #endif |
85 | NULL |
86 | }; |
87 | |
88 | static struct parsed_partitions *allocate_partitions(struct gendisk *hd) |
89 | { |
90 | struct parsed_partitions *state; |
91 | int nr = DISK_MAX_PARTS; |
92 | |
93 | state = kzalloc(size: sizeof(*state), GFP_KERNEL); |
94 | if (!state) |
95 | return NULL; |
96 | |
97 | state->parts = vzalloc(array_size(nr, sizeof(state->parts[0]))); |
98 | if (!state->parts) { |
99 | kfree(objp: state); |
100 | return NULL; |
101 | } |
102 | |
103 | state->limit = nr; |
104 | |
105 | return state; |
106 | } |
107 | |
108 | static void free_partitions(struct parsed_partitions *state) |
109 | { |
110 | vfree(addr: state->parts); |
111 | kfree(objp: state); |
112 | } |
113 | |
114 | static struct parsed_partitions *check_partition(struct gendisk *hd) |
115 | { |
116 | struct parsed_partitions *state; |
117 | int i, res, err; |
118 | |
119 | state = allocate_partitions(hd); |
120 | if (!state) |
121 | return NULL; |
122 | state->pp_buf = (char *)__get_free_page(GFP_KERNEL); |
123 | if (!state->pp_buf) { |
124 | free_partitions(state); |
125 | return NULL; |
126 | } |
127 | state->pp_buf[0] = '\0'; |
128 | |
129 | state->disk = hd; |
130 | snprintf(buf: state->name, BDEVNAME_SIZE, fmt: "%s" , hd->disk_name); |
131 | snprintf(buf: state->pp_buf, PAGE_SIZE, fmt: " %s:" , state->name); |
132 | if (isdigit(c: state->name[strlen(state->name)-1])) |
133 | sprintf(buf: state->name, fmt: "p" ); |
134 | |
135 | i = res = err = 0; |
136 | while (!res && check_part[i]) { |
137 | memset(state->parts, 0, state->limit * sizeof(state->parts[0])); |
138 | res = check_part[i++](state); |
139 | if (res < 0) { |
140 | /* |
141 | * We have hit an I/O error which we don't report now. |
142 | * But record it, and let the others do their job. |
143 | */ |
144 | err = res; |
145 | res = 0; |
146 | } |
147 | |
148 | } |
149 | if (res > 0) { |
150 | printk(KERN_INFO "%s" , state->pp_buf); |
151 | |
152 | free_page((unsigned long)state->pp_buf); |
153 | return state; |
154 | } |
155 | if (state->access_beyond_eod) |
156 | err = -ENOSPC; |
157 | /* |
158 | * The partition is unrecognized. So report I/O errors if there were any |
159 | */ |
160 | if (err) |
161 | res = err; |
162 | if (res) { |
163 | strlcat(p: state->pp_buf, |
164 | q: " unable to read partition table\n" , PAGE_SIZE); |
165 | printk(KERN_INFO "%s" , state->pp_buf); |
166 | } |
167 | |
168 | free_page((unsigned long)state->pp_buf); |
169 | free_partitions(state); |
170 | return ERR_PTR(error: res); |
171 | } |
172 | |
173 | static ssize_t part_partition_show(struct device *dev, |
174 | struct device_attribute *attr, char *buf) |
175 | { |
176 | return sprintf(buf, fmt: "%d\n" , dev_to_bdev(dev)->bd_partno); |
177 | } |
178 | |
179 | static ssize_t part_start_show(struct device *dev, |
180 | struct device_attribute *attr, char *buf) |
181 | { |
182 | return sprintf(buf, fmt: "%llu\n" , dev_to_bdev(dev)->bd_start_sect); |
183 | } |
184 | |
185 | static ssize_t part_ro_show(struct device *dev, |
186 | struct device_attribute *attr, char *buf) |
187 | { |
188 | return sprintf(buf, fmt: "%d\n" , bdev_read_only(dev_to_bdev(dev))); |
189 | } |
190 | |
191 | static ssize_t part_alignment_offset_show(struct device *dev, |
192 | struct device_attribute *attr, char *buf) |
193 | { |
194 | return sprintf(buf, fmt: "%u\n" , bdev_alignment_offset(dev_to_bdev(dev))); |
195 | } |
196 | |
197 | static ssize_t part_discard_alignment_show(struct device *dev, |
198 | struct device_attribute *attr, char *buf) |
199 | { |
200 | return sprintf(buf, fmt: "%u\n" , bdev_discard_alignment(dev_to_bdev(dev))); |
201 | } |
202 | |
203 | static DEVICE_ATTR(partition, 0444, part_partition_show, NULL); |
204 | static DEVICE_ATTR(start, 0444, part_start_show, NULL); |
205 | static DEVICE_ATTR(size, 0444, part_size_show, NULL); |
206 | static DEVICE_ATTR(ro, 0444, part_ro_show, NULL); |
207 | static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL); |
208 | static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL); |
209 | static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); |
210 | static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); |
211 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
212 | static struct device_attribute dev_attr_fail = |
213 | __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); |
214 | #endif |
215 | |
216 | static struct attribute *part_attrs[] = { |
217 | &dev_attr_partition.attr, |
218 | &dev_attr_start.attr, |
219 | &dev_attr_size.attr, |
220 | &dev_attr_ro.attr, |
221 | &dev_attr_alignment_offset.attr, |
222 | &dev_attr_discard_alignment.attr, |
223 | &dev_attr_stat.attr, |
224 | &dev_attr_inflight.attr, |
225 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
226 | &dev_attr_fail.attr, |
227 | #endif |
228 | NULL |
229 | }; |
230 | |
231 | static const struct attribute_group part_attr_group = { |
232 | .attrs = part_attrs, |
233 | }; |
234 | |
235 | static const struct attribute_group *part_attr_groups[] = { |
236 | &part_attr_group, |
237 | #ifdef CONFIG_BLK_DEV_IO_TRACE |
238 | &blk_trace_attr_group, |
239 | #endif |
240 | NULL |
241 | }; |
242 | |
243 | static void part_release(struct device *dev) |
244 | { |
245 | put_disk(dev_to_bdev(dev)->bd_disk); |
246 | iput(dev_to_bdev(dev)->bd_inode); |
247 | } |
248 | |
249 | static int part_uevent(const struct device *dev, struct kobj_uevent_env *env) |
250 | { |
251 | const struct block_device *part = dev_to_bdev(dev); |
252 | |
253 | add_uevent_var(env, format: "PARTN=%u" , part->bd_partno); |
254 | if (part->bd_meta_info && part->bd_meta_info->volname[0]) |
255 | add_uevent_var(env, format: "PARTNAME=%s" , part->bd_meta_info->volname); |
256 | return 0; |
257 | } |
258 | |
259 | const struct device_type part_type = { |
260 | .name = "partition" , |
261 | .groups = part_attr_groups, |
262 | .release = part_release, |
263 | .uevent = part_uevent, |
264 | }; |
265 | |
266 | void drop_partition(struct block_device *part) |
267 | { |
268 | lockdep_assert_held(&part->bd_disk->open_mutex); |
269 | |
270 | xa_erase(&part->bd_disk->part_tbl, index: part->bd_partno); |
271 | kobject_put(kobj: part->bd_holder_dir); |
272 | |
273 | device_del(dev: &part->bd_device); |
274 | put_device(dev: &part->bd_device); |
275 | } |
276 | |
277 | static ssize_t whole_disk_show(struct device *dev, |
278 | struct device_attribute *attr, char *buf) |
279 | { |
280 | return 0; |
281 | } |
282 | static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); |
283 | |
284 | /* |
285 | * Must be called either with open_mutex held, before a disk can be opened or |
286 | * after all disk users are gone. |
287 | */ |
288 | static struct block_device *add_partition(struct gendisk *disk, int partno, |
289 | sector_t start, sector_t len, int flags, |
290 | struct partition_meta_info *info) |
291 | { |
292 | dev_t devt = MKDEV(0, 0); |
293 | struct device *ddev = disk_to_dev(disk); |
294 | struct device *pdev; |
295 | struct block_device *bdev; |
296 | const char *dname; |
297 | int err; |
298 | |
299 | lockdep_assert_held(&disk->open_mutex); |
300 | |
301 | if (partno >= DISK_MAX_PARTS) |
302 | return ERR_PTR(error: -EINVAL); |
303 | |
304 | /* |
305 | * Partitions are not supported on zoned block devices that are used as |
306 | * such. |
307 | */ |
308 | if (bdev_is_zoned(bdev: disk->part0)) { |
309 | pr_warn("%s: partitions not supported on host managed zoned block device\n" , |
310 | disk->disk_name); |
311 | return ERR_PTR(error: -ENXIO); |
312 | } |
313 | |
314 | if (xa_load(&disk->part_tbl, index: partno)) |
315 | return ERR_PTR(error: -EBUSY); |
316 | |
317 | /* ensure we always have a reference to the whole disk */ |
318 | get_device(disk_to_dev(disk)); |
319 | |
320 | err = -ENOMEM; |
321 | bdev = bdev_alloc(disk, partno); |
322 | if (!bdev) |
323 | goto out_put_disk; |
324 | |
325 | bdev->bd_start_sect = start; |
326 | bdev_set_nr_sectors(bdev, sectors: len); |
327 | |
328 | pdev = &bdev->bd_device; |
329 | dname = dev_name(dev: ddev); |
330 | if (isdigit(c: dname[strlen(dname) - 1])) |
331 | dev_set_name(dev: pdev, name: "%sp%d" , dname, partno); |
332 | else |
333 | dev_set_name(dev: pdev, name: "%s%d" , dname, partno); |
334 | |
335 | device_initialize(dev: pdev); |
336 | pdev->class = &block_class; |
337 | pdev->type = &part_type; |
338 | pdev->parent = ddev; |
339 | |
340 | /* in consecutive minor range? */ |
341 | if (bdev->bd_partno < disk->minors) { |
342 | devt = MKDEV(disk->major, disk->first_minor + bdev->bd_partno); |
343 | } else { |
344 | err = blk_alloc_ext_minor(); |
345 | if (err < 0) |
346 | goto out_put; |
347 | devt = MKDEV(BLOCK_EXT_MAJOR, err); |
348 | } |
349 | pdev->devt = devt; |
350 | |
351 | if (info) { |
352 | err = -ENOMEM; |
353 | bdev->bd_meta_info = kmemdup(p: info, size: sizeof(*info), GFP_KERNEL); |
354 | if (!bdev->bd_meta_info) |
355 | goto out_put; |
356 | } |
357 | |
358 | /* delay uevent until 'holders' subdir is created */ |
359 | dev_set_uevent_suppress(dev: pdev, val: 1); |
360 | err = device_add(dev: pdev); |
361 | if (err) |
362 | goto out_put; |
363 | |
364 | err = -ENOMEM; |
365 | bdev->bd_holder_dir = kobject_create_and_add(name: "holders" , parent: &pdev->kobj); |
366 | if (!bdev->bd_holder_dir) |
367 | goto out_del; |
368 | |
369 | dev_set_uevent_suppress(dev: pdev, val: 0); |
370 | if (flags & ADDPART_FLAG_WHOLEDISK) { |
371 | err = device_create_file(device: pdev, entry: &dev_attr_whole_disk); |
372 | if (err) |
373 | goto out_del; |
374 | } |
375 | |
376 | /* everything is up and running, commence */ |
377 | err = xa_insert(xa: &disk->part_tbl, index: partno, entry: bdev, GFP_KERNEL); |
378 | if (err) |
379 | goto out_del; |
380 | bdev_add(bdev, dev: devt); |
381 | |
382 | /* suppress uevent if the disk suppresses it */ |
383 | if (!dev_get_uevent_suppress(dev: ddev)) |
384 | kobject_uevent(kobj: &pdev->kobj, action: KOBJ_ADD); |
385 | return bdev; |
386 | |
387 | out_del: |
388 | kobject_put(kobj: bdev->bd_holder_dir); |
389 | device_del(dev: pdev); |
390 | out_put: |
391 | put_device(dev: pdev); |
392 | return ERR_PTR(error: err); |
393 | out_put_disk: |
394 | put_disk(disk); |
395 | return ERR_PTR(error: err); |
396 | } |
397 | |
398 | static bool partition_overlaps(struct gendisk *disk, sector_t start, |
399 | sector_t length, int skip_partno) |
400 | { |
401 | struct block_device *part; |
402 | bool overlap = false; |
403 | unsigned long idx; |
404 | |
405 | rcu_read_lock(); |
406 | xa_for_each_start(&disk->part_tbl, idx, part, 1) { |
407 | if (part->bd_partno != skip_partno && |
408 | start < part->bd_start_sect + bdev_nr_sectors(bdev: part) && |
409 | start + length > part->bd_start_sect) { |
410 | overlap = true; |
411 | break; |
412 | } |
413 | } |
414 | rcu_read_unlock(); |
415 | |
416 | return overlap; |
417 | } |
418 | |
419 | int bdev_add_partition(struct gendisk *disk, int partno, sector_t start, |
420 | sector_t length) |
421 | { |
422 | struct block_device *part; |
423 | int ret; |
424 | |
425 | mutex_lock(&disk->open_mutex); |
426 | if (!disk_live(disk)) { |
427 | ret = -ENXIO; |
428 | goto out; |
429 | } |
430 | |
431 | if (disk->flags & GENHD_FL_NO_PART) { |
432 | ret = -EINVAL; |
433 | goto out; |
434 | } |
435 | |
436 | if (partition_overlaps(disk, start, length, skip_partno: -1)) { |
437 | ret = -EBUSY; |
438 | goto out; |
439 | } |
440 | |
441 | part = add_partition(disk, partno, start, len: length, |
442 | ADDPART_FLAG_NONE, NULL); |
443 | ret = PTR_ERR_OR_ZERO(ptr: part); |
444 | out: |
445 | mutex_unlock(lock: &disk->open_mutex); |
446 | return ret; |
447 | } |
448 | |
449 | int bdev_del_partition(struct gendisk *disk, int partno) |
450 | { |
451 | struct block_device *part = NULL; |
452 | int ret = -ENXIO; |
453 | |
454 | mutex_lock(&disk->open_mutex); |
455 | part = xa_load(&disk->part_tbl, index: partno); |
456 | if (!part) |
457 | goto out_unlock; |
458 | |
459 | ret = -EBUSY; |
460 | if (atomic_read(v: &part->bd_openers)) |
461 | goto out_unlock; |
462 | |
463 | /* |
464 | * We verified that @part->bd_openers is zero above and so |
465 | * @part->bd_holder{_ops} can't be set. And since we hold |
466 | * @disk->open_mutex the device can't be claimed by anyone. |
467 | * |
468 | * So no need to call @part->bd_holder_ops->mark_dead() here. |
469 | * Just delete the partition and invalidate it. |
470 | */ |
471 | |
472 | remove_inode_hash(inode: part->bd_inode); |
473 | invalidate_bdev(bdev: part); |
474 | drop_partition(part); |
475 | ret = 0; |
476 | out_unlock: |
477 | mutex_unlock(lock: &disk->open_mutex); |
478 | return ret; |
479 | } |
480 | |
481 | int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start, |
482 | sector_t length) |
483 | { |
484 | struct block_device *part = NULL; |
485 | int ret = -ENXIO; |
486 | |
487 | mutex_lock(&disk->open_mutex); |
488 | part = xa_load(&disk->part_tbl, index: partno); |
489 | if (!part) |
490 | goto out_unlock; |
491 | |
492 | ret = -EINVAL; |
493 | if (start != part->bd_start_sect) |
494 | goto out_unlock; |
495 | |
496 | ret = -EBUSY; |
497 | if (partition_overlaps(disk, start, length, skip_partno: partno)) |
498 | goto out_unlock; |
499 | |
500 | bdev_set_nr_sectors(bdev: part, sectors: length); |
501 | |
502 | ret = 0; |
503 | out_unlock: |
504 | mutex_unlock(lock: &disk->open_mutex); |
505 | return ret; |
506 | } |
507 | |
508 | static bool disk_unlock_native_capacity(struct gendisk *disk) |
509 | { |
510 | if (!disk->fops->unlock_native_capacity || |
511 | test_and_set_bit(GD_NATIVE_CAPACITY, addr: &disk->state)) { |
512 | printk(KERN_CONT "truncated\n" ); |
513 | return false; |
514 | } |
515 | |
516 | printk(KERN_CONT "enabling native capacity\n" ); |
517 | disk->fops->unlock_native_capacity(disk); |
518 | return true; |
519 | } |
520 | |
521 | static bool blk_add_partition(struct gendisk *disk, |
522 | struct parsed_partitions *state, int p) |
523 | { |
524 | sector_t size = state->parts[p].size; |
525 | sector_t from = state->parts[p].from; |
526 | struct block_device *part; |
527 | |
528 | if (!size) |
529 | return true; |
530 | |
531 | if (from >= get_capacity(disk)) { |
532 | printk(KERN_WARNING |
533 | "%s: p%d start %llu is beyond EOD, " , |
534 | disk->disk_name, p, (unsigned long long) from); |
535 | if (disk_unlock_native_capacity(disk)) |
536 | return false; |
537 | return true; |
538 | } |
539 | |
540 | if (from + size > get_capacity(disk)) { |
541 | printk(KERN_WARNING |
542 | "%s: p%d size %llu extends beyond EOD, " , |
543 | disk->disk_name, p, (unsigned long long) size); |
544 | |
545 | if (disk_unlock_native_capacity(disk)) |
546 | return false; |
547 | |
548 | /* |
549 | * We can not ignore partitions of broken tables created by for |
550 | * example camera firmware, but we limit them to the end of the |
551 | * disk to avoid creating invalid block devices. |
552 | */ |
553 | size = get_capacity(disk) - from; |
554 | } |
555 | |
556 | part = add_partition(disk, partno: p, start: from, len: size, flags: state->parts[p].flags, |
557 | info: &state->parts[p].info); |
558 | if (IS_ERR(ptr: part) && PTR_ERR(ptr: part) != -ENXIO) { |
559 | printk(KERN_ERR " %s: p%d could not be added: %pe\n" , |
560 | disk->disk_name, p, part); |
561 | return true; |
562 | } |
563 | |
564 | if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && |
565 | (state->parts[p].flags & ADDPART_FLAG_RAID)) |
566 | md_autodetect_dev(dev: part->bd_dev); |
567 | |
568 | return true; |
569 | } |
570 | |
571 | static int blk_add_partitions(struct gendisk *disk) |
572 | { |
573 | struct parsed_partitions *state; |
574 | int ret = -EAGAIN, p; |
575 | |
576 | if (disk->flags & GENHD_FL_NO_PART) |
577 | return 0; |
578 | |
579 | if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) |
580 | return 0; |
581 | |
582 | state = check_partition(hd: disk); |
583 | if (!state) |
584 | return 0; |
585 | if (IS_ERR(ptr: state)) { |
586 | /* |
587 | * I/O error reading the partition table. If we tried to read |
588 | * beyond EOD, retry after unlocking the native capacity. |
589 | */ |
590 | if (PTR_ERR(ptr: state) == -ENOSPC) { |
591 | printk(KERN_WARNING "%s: partition table beyond EOD, " , |
592 | disk->disk_name); |
593 | if (disk_unlock_native_capacity(disk)) |
594 | return -EAGAIN; |
595 | } |
596 | return -EIO; |
597 | } |
598 | |
599 | /* |
600 | * Partitions are not supported on host managed zoned block devices. |
601 | */ |
602 | if (bdev_is_zoned(bdev: disk->part0)) { |
603 | pr_warn("%s: ignoring partition table on host managed zoned block device\n" , |
604 | disk->disk_name); |
605 | ret = 0; |
606 | goto out_free_state; |
607 | } |
608 | |
609 | /* |
610 | * If we read beyond EOD, try unlocking native capacity even if the |
611 | * partition table was successfully read as we could be missing some |
612 | * partitions. |
613 | */ |
614 | if (state->access_beyond_eod) { |
615 | printk(KERN_WARNING |
616 | "%s: partition table partially beyond EOD, " , |
617 | disk->disk_name); |
618 | if (disk_unlock_native_capacity(disk)) |
619 | goto out_free_state; |
620 | } |
621 | |
622 | /* tell userspace that the media / partition table may have changed */ |
623 | kobject_uevent(kobj: &disk_to_dev(disk)->kobj, action: KOBJ_CHANGE); |
624 | |
625 | for (p = 1; p < state->limit; p++) |
626 | if (!blk_add_partition(disk, state, p)) |
627 | goto out_free_state; |
628 | |
629 | ret = 0; |
630 | out_free_state: |
631 | free_partitions(state); |
632 | return ret; |
633 | } |
634 | |
635 | int bdev_disk_changed(struct gendisk *disk, bool invalidate) |
636 | { |
637 | struct block_device *part; |
638 | unsigned long idx; |
639 | int ret = 0; |
640 | |
641 | lockdep_assert_held(&disk->open_mutex); |
642 | |
643 | if (!disk_live(disk)) |
644 | return -ENXIO; |
645 | |
646 | rescan: |
647 | if (disk->open_partitions) |
648 | return -EBUSY; |
649 | sync_blockdev(bdev: disk->part0); |
650 | invalidate_bdev(bdev: disk->part0); |
651 | |
652 | xa_for_each_start(&disk->part_tbl, idx, part, 1) { |
653 | /* |
654 | * Remove the block device from the inode hash, so that |
655 | * it cannot be looked up any more even when openers |
656 | * still hold references. |
657 | */ |
658 | remove_inode_hash(inode: part->bd_inode); |
659 | |
660 | /* |
661 | * If @disk->open_partitions isn't elevated but there's |
662 | * still an active holder of that block device things |
663 | * are broken. |
664 | */ |
665 | WARN_ON_ONCE(atomic_read(&part->bd_openers)); |
666 | invalidate_bdev(bdev: part); |
667 | drop_partition(part); |
668 | } |
669 | clear_bit(GD_NEED_PART_SCAN, addr: &disk->state); |
670 | |
671 | /* |
672 | * Historically we only set the capacity to zero for devices that |
673 | * support partitions (independ of actually having partitions created). |
674 | * Doing that is rather inconsistent, but changing it broke legacy |
675 | * udisks polling for legacy ide-cdrom devices. Use the crude check |
676 | * below to get the sane behavior for most device while not breaking |
677 | * userspace for this particular setup. |
678 | */ |
679 | if (invalidate) { |
680 | if (!(disk->flags & GENHD_FL_NO_PART) || |
681 | !(disk->flags & GENHD_FL_REMOVABLE)) |
682 | set_capacity(disk, size: 0); |
683 | } |
684 | |
685 | if (get_capacity(disk)) { |
686 | ret = blk_add_partitions(disk); |
687 | if (ret == -EAGAIN) |
688 | goto rescan; |
689 | } else if (invalidate) { |
690 | /* |
691 | * Tell userspace that the media / partition table may have |
692 | * changed. |
693 | */ |
694 | kobject_uevent(kobj: &disk_to_dev(disk)->kobj, action: KOBJ_CHANGE); |
695 | } |
696 | |
697 | return ret; |
698 | } |
699 | /* |
700 | * Only exported for loop and dasd for historic reasons. Don't use in new |
701 | * code! |
702 | */ |
703 | EXPORT_SYMBOL_GPL(bdev_disk_changed); |
704 | |
705 | void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) |
706 | { |
707 | struct address_space *mapping = state->disk->part0->bd_inode->i_mapping; |
708 | struct folio *folio; |
709 | |
710 | if (n >= get_capacity(disk: state->disk)) { |
711 | state->access_beyond_eod = true; |
712 | goto out; |
713 | } |
714 | |
715 | folio = read_mapping_folio(mapping, index: n >> PAGE_SECTORS_SHIFT, NULL); |
716 | if (IS_ERR(ptr: folio)) |
717 | goto out; |
718 | |
719 | p->v = folio; |
720 | return folio_address(folio) + offset_in_folio(folio, n * SECTOR_SIZE); |
721 | out: |
722 | p->v = NULL; |
723 | return NULL; |
724 | } |
725 | |