Commit | Line | Data |
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94ea4158 AV |
1 | /* |
2 | * Code extracted from drivers/block/genhd.c | |
3 | * Copyright (C) 1991-1998 Linus Torvalds | |
4 | * Re-organised Feb 1998 Russell King | |
5 | * | |
6 | * We now have independent partition support from the | |
7 | * block drivers, which allows all the partition code to | |
8 | * be grouped in one location, and it to be mostly self | |
9 | * contained. | |
10 | */ | |
11 | ||
12 | #include <linux/init.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/fs.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/kmod.h> | |
17 | #include <linux/ctype.h> | |
18 | #include <linux/genhd.h> | |
19 | #include <linux/blktrace_api.h> | |
20 | ||
21 | #include "partitions/check.h" | |
22 | ||
23 | #ifdef CONFIG_BLK_DEV_MD | |
24 | extern void md_autodetect_dev(dev_t dev); | |
25 | #endif | |
26 | ||
27 | /* | |
28 | * disk_name() is used by partition check code and the genhd driver. | |
29 | * It formats the devicename of the indicated disk into | |
30 | * the supplied buffer (of size at least 32), and returns | |
31 | * a pointer to that same buffer (for convenience). | |
32 | */ | |
33 | ||
34 | char *disk_name(struct gendisk *hd, int partno, char *buf) | |
35 | { | |
36 | if (!partno) | |
37 | snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name); | |
38 | else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) | |
39 | snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno); | |
40 | else | |
41 | snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno); | |
42 | ||
43 | return buf; | |
44 | } | |
45 | ||
46 | const char *bdevname(struct block_device *bdev, char *buf) | |
47 | { | |
48 | return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf); | |
49 | } | |
50 | ||
51 | EXPORT_SYMBOL(bdevname); | |
52 | ||
53 | /* | |
54 | * There's very little reason to use this, you should really | |
55 | * have a struct block_device just about everywhere and use | |
56 | * bdevname() instead. | |
57 | */ | |
58 | const char *__bdevname(dev_t dev, char *buffer) | |
59 | { | |
60 | scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)", | |
61 | MAJOR(dev), MINOR(dev)); | |
62 | return buffer; | |
63 | } | |
64 | ||
65 | EXPORT_SYMBOL(__bdevname); | |
66 | ||
67 | static ssize_t part_partition_show(struct device *dev, | |
68 | struct device_attribute *attr, char *buf) | |
69 | { | |
70 | struct hd_struct *p = dev_to_part(dev); | |
71 | ||
72 | return sprintf(buf, "%d\n", p->partno); | |
73 | } | |
74 | ||
75 | static ssize_t part_start_show(struct device *dev, | |
76 | struct device_attribute *attr, char *buf) | |
77 | { | |
78 | struct hd_struct *p = dev_to_part(dev); | |
79 | ||
80 | return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect); | |
81 | } | |
82 | ||
83 | ssize_t part_size_show(struct device *dev, | |
84 | struct device_attribute *attr, char *buf) | |
85 | { | |
86 | struct hd_struct *p = dev_to_part(dev); | |
87 | return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects); | |
88 | } | |
89 | ||
90 | static ssize_t part_ro_show(struct device *dev, | |
91 | struct device_attribute *attr, char *buf) | |
92 | { | |
93 | struct hd_struct *p = dev_to_part(dev); | |
94 | return sprintf(buf, "%d\n", p->policy ? 1 : 0); | |
95 | } | |
96 | ||
97 | static ssize_t part_alignment_offset_show(struct device *dev, | |
98 | struct device_attribute *attr, char *buf) | |
99 | { | |
100 | struct hd_struct *p = dev_to_part(dev); | |
101 | return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset); | |
102 | } | |
103 | ||
104 | static ssize_t part_discard_alignment_show(struct device *dev, | |
105 | struct device_attribute *attr, char *buf) | |
106 | { | |
107 | struct hd_struct *p = dev_to_part(dev); | |
108 | return sprintf(buf, "%u\n", p->discard_alignment); | |
109 | } | |
110 | ||
111 | ssize_t part_stat_show(struct device *dev, | |
112 | struct device_attribute *attr, char *buf) | |
113 | { | |
114 | struct hd_struct *p = dev_to_part(dev); | |
115 | int cpu; | |
116 | ||
117 | cpu = part_stat_lock(); | |
118 | part_round_stats(cpu, p); | |
119 | part_stat_unlock(); | |
120 | return sprintf(buf, | |
121 | "%8lu %8lu %8llu %8u " | |
122 | "%8lu %8lu %8llu %8u " | |
123 | "%8u %8u %8u" | |
124 | "\n", | |
125 | part_stat_read(p, ios[READ]), | |
126 | part_stat_read(p, merges[READ]), | |
127 | (unsigned long long)part_stat_read(p, sectors[READ]), | |
128 | jiffies_to_msecs(part_stat_read(p, ticks[READ])), | |
129 | part_stat_read(p, ios[WRITE]), | |
130 | part_stat_read(p, merges[WRITE]), | |
131 | (unsigned long long)part_stat_read(p, sectors[WRITE]), | |
132 | jiffies_to_msecs(part_stat_read(p, ticks[WRITE])), | |
133 | part_in_flight(p), | |
134 | jiffies_to_msecs(part_stat_read(p, io_ticks)), | |
135 | jiffies_to_msecs(part_stat_read(p, time_in_queue))); | |
136 | } | |
137 | ||
138 | ssize_t part_inflight_show(struct device *dev, | |
139 | struct device_attribute *attr, char *buf) | |
140 | { | |
141 | struct hd_struct *p = dev_to_part(dev); | |
142 | ||
143 | return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]), | |
144 | atomic_read(&p->in_flight[1])); | |
145 | } | |
146 | ||
147 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
148 | ssize_t part_fail_show(struct device *dev, | |
149 | struct device_attribute *attr, char *buf) | |
150 | { | |
151 | struct hd_struct *p = dev_to_part(dev); | |
152 | ||
153 | return sprintf(buf, "%d\n", p->make_it_fail); | |
154 | } | |
155 | ||
156 | ssize_t part_fail_store(struct device *dev, | |
157 | struct device_attribute *attr, | |
158 | const char *buf, size_t count) | |
159 | { | |
160 | struct hd_struct *p = dev_to_part(dev); | |
161 | int i; | |
162 | ||
163 | if (count > 0 && sscanf(buf, "%d", &i) > 0) | |
164 | p->make_it_fail = (i == 0) ? 0 : 1; | |
165 | ||
166 | return count; | |
167 | } | |
168 | #endif | |
169 | ||
170 | static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL); | |
171 | static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL); | |
172 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); | |
173 | static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL); | |
174 | static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL); | |
175 | static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show, | |
176 | NULL); | |
177 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); | |
178 | static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); | |
179 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
180 | static struct device_attribute dev_attr_fail = | |
181 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); | |
182 | #endif | |
183 | ||
184 | static struct attribute *part_attrs[] = { | |
185 | &dev_attr_partition.attr, | |
186 | &dev_attr_start.attr, | |
187 | &dev_attr_size.attr, | |
188 | &dev_attr_ro.attr, | |
189 | &dev_attr_alignment_offset.attr, | |
190 | &dev_attr_discard_alignment.attr, | |
191 | &dev_attr_stat.attr, | |
192 | &dev_attr_inflight.attr, | |
193 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
194 | &dev_attr_fail.attr, | |
195 | #endif | |
196 | NULL | |
197 | }; | |
198 | ||
199 | static struct attribute_group part_attr_group = { | |
200 | .attrs = part_attrs, | |
201 | }; | |
202 | ||
203 | static const struct attribute_group *part_attr_groups[] = { | |
204 | &part_attr_group, | |
205 | #ifdef CONFIG_BLK_DEV_IO_TRACE | |
206 | &blk_trace_attr_group, | |
207 | #endif | |
208 | NULL | |
209 | }; | |
210 | ||
211 | static void part_release(struct device *dev) | |
212 | { | |
213 | struct hd_struct *p = dev_to_part(dev); | |
214 | free_part_stats(p); | |
215 | free_part_info(p); | |
216 | kfree(p); | |
217 | } | |
218 | ||
219 | struct device_type part_type = { | |
220 | .name = "partition", | |
221 | .groups = part_attr_groups, | |
222 | .release = part_release, | |
223 | }; | |
224 | ||
225 | static void delete_partition_rcu_cb(struct rcu_head *head) | |
226 | { | |
227 | struct hd_struct *part = container_of(head, struct hd_struct, rcu_head); | |
228 | ||
229 | part->start_sect = 0; | |
230 | part->nr_sects = 0; | |
231 | part_stat_set_all(part, 0); | |
232 | put_device(part_to_dev(part)); | |
233 | } | |
234 | ||
235 | void __delete_partition(struct hd_struct *part) | |
236 | { | |
237 | call_rcu(&part->rcu_head, delete_partition_rcu_cb); | |
238 | } | |
239 | ||
240 | void delete_partition(struct gendisk *disk, int partno) | |
241 | { | |
242 | struct disk_part_tbl *ptbl = disk->part_tbl; | |
243 | struct hd_struct *part; | |
244 | ||
245 | if (partno >= ptbl->len) | |
246 | return; | |
247 | ||
248 | part = ptbl->part[partno]; | |
249 | if (!part) | |
250 | return; | |
251 | ||
252 | blk_free_devt(part_devt(part)); | |
253 | rcu_assign_pointer(ptbl->part[partno], NULL); | |
254 | rcu_assign_pointer(ptbl->last_lookup, NULL); | |
255 | kobject_put(part->holder_dir); | |
256 | device_del(part_to_dev(part)); | |
257 | ||
258 | hd_struct_put(part); | |
259 | } | |
260 | ||
261 | static ssize_t whole_disk_show(struct device *dev, | |
262 | struct device_attribute *attr, char *buf) | |
263 | { | |
264 | return 0; | |
265 | } | |
266 | static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH, | |
267 | whole_disk_show, NULL); | |
268 | ||
269 | struct hd_struct *add_partition(struct gendisk *disk, int partno, | |
270 | sector_t start, sector_t len, int flags, | |
271 | struct partition_meta_info *info) | |
272 | { | |
273 | struct hd_struct *p; | |
274 | dev_t devt = MKDEV(0, 0); | |
275 | struct device *ddev = disk_to_dev(disk); | |
276 | struct device *pdev; | |
277 | struct disk_part_tbl *ptbl; | |
278 | const char *dname; | |
279 | int err; | |
280 | ||
281 | err = disk_expand_part_tbl(disk, partno); | |
282 | if (err) | |
283 | return ERR_PTR(err); | |
284 | ptbl = disk->part_tbl; | |
285 | ||
286 | if (ptbl->part[partno]) | |
287 | return ERR_PTR(-EBUSY); | |
288 | ||
289 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
290 | if (!p) | |
291 | return ERR_PTR(-EBUSY); | |
292 | ||
293 | if (!init_part_stats(p)) { | |
294 | err = -ENOMEM; | |
295 | goto out_free; | |
296 | } | |
297 | pdev = part_to_dev(p); | |
298 | ||
299 | p->start_sect = start; | |
300 | p->alignment_offset = | |
301 | queue_limit_alignment_offset(&disk->queue->limits, start); | |
302 | p->discard_alignment = | |
303 | queue_limit_discard_alignment(&disk->queue->limits, start); | |
304 | p->nr_sects = len; | |
305 | p->partno = partno; | |
306 | p->policy = get_disk_ro(disk); | |
307 | ||
308 | if (info) { | |
309 | struct partition_meta_info *pinfo = alloc_part_info(disk); | |
310 | if (!pinfo) | |
311 | goto out_free_stats; | |
312 | memcpy(pinfo, info, sizeof(*info)); | |
313 | p->info = pinfo; | |
314 | } | |
315 | ||
316 | dname = dev_name(ddev); | |
317 | if (isdigit(dname[strlen(dname) - 1])) | |
318 | dev_set_name(pdev, "%sp%d", dname, partno); | |
319 | else | |
320 | dev_set_name(pdev, "%s%d", dname, partno); | |
321 | ||
322 | device_initialize(pdev); | |
323 | pdev->class = &block_class; | |
324 | pdev->type = &part_type; | |
325 | pdev->parent = ddev; | |
326 | ||
327 | err = blk_alloc_devt(p, &devt); | |
328 | if (err) | |
329 | goto out_free_info; | |
330 | pdev->devt = devt; | |
331 | ||
332 | /* delay uevent until 'holders' subdir is created */ | |
333 | dev_set_uevent_suppress(pdev, 1); | |
334 | err = device_add(pdev); | |
335 | if (err) | |
336 | goto out_put; | |
337 | ||
338 | err = -ENOMEM; | |
339 | p->holder_dir = kobject_create_and_add("holders", &pdev->kobj); | |
340 | if (!p->holder_dir) | |
341 | goto out_del; | |
342 | ||
343 | dev_set_uevent_suppress(pdev, 0); | |
344 | if (flags & ADDPART_FLAG_WHOLEDISK) { | |
345 | err = device_create_file(pdev, &dev_attr_whole_disk); | |
346 | if (err) | |
347 | goto out_del; | |
348 | } | |
349 | ||
350 | /* everything is up and running, commence */ | |
351 | rcu_assign_pointer(ptbl->part[partno], p); | |
352 | ||
353 | /* suppress uevent if the disk suppresses it */ | |
354 | if (!dev_get_uevent_suppress(ddev)) | |
355 | kobject_uevent(&pdev->kobj, KOBJ_ADD); | |
356 | ||
357 | hd_ref_init(p); | |
358 | return p; | |
359 | ||
360 | out_free_info: | |
361 | free_part_info(p); | |
362 | out_free_stats: | |
363 | free_part_stats(p); | |
364 | out_free: | |
365 | kfree(p); | |
366 | return ERR_PTR(err); | |
367 | out_del: | |
368 | kobject_put(p->holder_dir); | |
369 | device_del(pdev); | |
370 | out_put: | |
371 | put_device(pdev); | |
372 | blk_free_devt(devt); | |
373 | return ERR_PTR(err); | |
374 | } | |
375 | ||
376 | static bool disk_unlock_native_capacity(struct gendisk *disk) | |
377 | { | |
378 | const struct block_device_operations *bdops = disk->fops; | |
379 | ||
380 | if (bdops->unlock_native_capacity && | |
381 | !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) { | |
382 | printk(KERN_CONT "enabling native capacity\n"); | |
383 | bdops->unlock_native_capacity(disk); | |
384 | disk->flags |= GENHD_FL_NATIVE_CAPACITY; | |
385 | return true; | |
386 | } else { | |
387 | printk(KERN_CONT "truncated\n"); | |
388 | return false; | |
389 | } | |
390 | } | |
391 | ||
fe316bf2 | 392 | static int drop_partitions(struct gendisk *disk, struct block_device *bdev) |
94ea4158 | 393 | { |
94ea4158 AV |
394 | struct disk_part_iter piter; |
395 | struct hd_struct *part; | |
fe316bf2 | 396 | int res; |
94ea4158 AV |
397 | |
398 | if (bdev->bd_part_count) | |
399 | return -EBUSY; | |
400 | res = invalidate_partition(disk, 0); | |
401 | if (res) | |
402 | return res; | |
403 | ||
404 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); | |
405 | while ((part = disk_part_iter_next(&piter))) | |
406 | delete_partition(disk, part->partno); | |
407 | disk_part_iter_exit(&piter); | |
408 | ||
fe316bf2 JN |
409 | return 0; |
410 | } | |
411 | ||
412 | int rescan_partitions(struct gendisk *disk, struct block_device *bdev) | |
413 | { | |
414 | struct parsed_partitions *state = NULL; | |
415 | struct hd_struct *part; | |
416 | int p, highest, res; | |
417 | rescan: | |
418 | if (state && !IS_ERR(state)) { | |
419 | kfree(state); | |
420 | state = NULL; | |
421 | } | |
422 | ||
423 | res = drop_partitions(disk, bdev); | |
424 | if (res) | |
425 | return res; | |
426 | ||
94ea4158 AV |
427 | if (disk->fops->revalidate_disk) |
428 | disk->fops->revalidate_disk(disk); | |
429 | check_disk_size_change(disk, bdev); | |
430 | bdev->bd_invalidated = 0; | |
431 | if (!get_capacity(disk) || !(state = check_partition(disk, bdev))) | |
432 | return 0; | |
433 | if (IS_ERR(state)) { | |
434 | /* | |
435 | * I/O error reading the partition table. If any | |
436 | * partition code tried to read beyond EOD, retry | |
437 | * after unlocking native capacity. | |
438 | */ | |
439 | if (PTR_ERR(state) == -ENOSPC) { | |
440 | printk(KERN_WARNING "%s: partition table beyond EOD, ", | |
441 | disk->disk_name); | |
442 | if (disk_unlock_native_capacity(disk)) | |
443 | goto rescan; | |
444 | } | |
445 | return -EIO; | |
446 | } | |
447 | /* | |
448 | * If any partition code tried to read beyond EOD, try | |
449 | * unlocking native capacity even if partition table is | |
450 | * successfully read as we could be missing some partitions. | |
451 | */ | |
452 | if (state->access_beyond_eod) { | |
453 | printk(KERN_WARNING | |
454 | "%s: partition table partially beyond EOD, ", | |
455 | disk->disk_name); | |
456 | if (disk_unlock_native_capacity(disk)) | |
457 | goto rescan; | |
458 | } | |
459 | ||
460 | /* tell userspace that the media / partition table may have changed */ | |
461 | kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); | |
462 | ||
463 | /* Detect the highest partition number and preallocate | |
464 | * disk->part_tbl. This is an optimization and not strictly | |
465 | * necessary. | |
466 | */ | |
467 | for (p = 1, highest = 0; p < state->limit; p++) | |
468 | if (state->parts[p].size) | |
469 | highest = p; | |
470 | ||
471 | disk_expand_part_tbl(disk, highest); | |
472 | ||
473 | /* add partitions */ | |
474 | for (p = 1; p < state->limit; p++) { | |
475 | sector_t size, from; | |
476 | struct partition_meta_info *info = NULL; | |
477 | ||
478 | size = state->parts[p].size; | |
479 | if (!size) | |
480 | continue; | |
481 | ||
482 | from = state->parts[p].from; | |
483 | if (from >= get_capacity(disk)) { | |
484 | printk(KERN_WARNING | |
485 | "%s: p%d start %llu is beyond EOD, ", | |
486 | disk->disk_name, p, (unsigned long long) from); | |
487 | if (disk_unlock_native_capacity(disk)) | |
488 | goto rescan; | |
489 | continue; | |
490 | } | |
491 | ||
492 | if (from + size > get_capacity(disk)) { | |
493 | printk(KERN_WARNING | |
494 | "%s: p%d size %llu extends beyond EOD, ", | |
495 | disk->disk_name, p, (unsigned long long) size); | |
496 | ||
497 | if (disk_unlock_native_capacity(disk)) { | |
498 | /* free state and restart */ | |
499 | goto rescan; | |
500 | } else { | |
501 | /* | |
502 | * we can not ignore partitions of broken tables | |
503 | * created by for example camera firmware, but | |
504 | * we limit them to the end of the disk to avoid | |
505 | * creating invalid block devices | |
506 | */ | |
507 | size = get_capacity(disk) - from; | |
508 | } | |
509 | } | |
510 | ||
511 | if (state->parts[p].has_info) | |
512 | info = &state->parts[p].info; | |
513 | part = add_partition(disk, p, from, size, | |
514 | state->parts[p].flags, | |
515 | &state->parts[p].info); | |
516 | if (IS_ERR(part)) { | |
517 | printk(KERN_ERR " %s: p%d could not be added: %ld\n", | |
518 | disk->disk_name, p, -PTR_ERR(part)); | |
519 | continue; | |
520 | } | |
521 | #ifdef CONFIG_BLK_DEV_MD | |
522 | if (state->parts[p].flags & ADDPART_FLAG_RAID) | |
523 | md_autodetect_dev(part_to_dev(part)->devt); | |
524 | #endif | |
525 | } | |
526 | kfree(state); | |
527 | return 0; | |
528 | } | |
529 | ||
fe316bf2 JN |
530 | int invalidate_partitions(struct gendisk *disk, struct block_device *bdev) |
531 | { | |
532 | int res; | |
533 | ||
534 | if (!bdev->bd_invalidated) | |
535 | return 0; | |
536 | ||
537 | res = drop_partitions(disk, bdev); | |
538 | if (res) | |
539 | return res; | |
540 | ||
541 | set_capacity(disk, 0); | |
542 | check_disk_size_change(disk, bdev); | |
543 | bdev->bd_invalidated = 0; | |
544 | /* tell userspace that the media / partition table may have changed */ | |
545 | kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); | |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
94ea4158 AV |
550 | unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) |
551 | { | |
552 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
553 | struct page *page; | |
554 | ||
555 | page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)), | |
556 | NULL); | |
557 | if (!IS_ERR(page)) { | |
558 | if (PageError(page)) | |
559 | goto fail; | |
560 | p->v = page; | |
561 | return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9); | |
562 | fail: | |
563 | page_cache_release(page); | |
564 | } | |
565 | p->v = NULL; | |
566 | return NULL; | |
567 | } | |
568 | ||
569 | EXPORT_SYMBOL(read_dev_sector); |