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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)part_nr_sects_read(p)); |
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 | rcu_assign_pointer(ptbl->part[partno], NULL); |
253 | rcu_assign_pointer(ptbl->last_lookup, NULL); |
254 | kobject_put(part->holder_dir); |
255 | device_del(part_to_dev(part)); |
256 | blk_free_devt(part_devt(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 | |
298 | seqcount_init(&p->nr_sects_seq); |
299 | pdev = part_to_dev(p); |
300 | |
301 | p->start_sect = start; |
302 | p->alignment_offset = |
303 | queue_limit_alignment_offset(&disk->queue->limits, start); |
304 | p->discard_alignment = |
305 | queue_limit_discard_alignment(&disk->queue->limits, start); |
306 | p->nr_sects = len; |
307 | p->partno = partno; |
308 | p->policy = get_disk_ro(disk); |
309 | |
310 | if (info) { |
311 | struct partition_meta_info *pinfo = alloc_part_info(disk); |
312 | if (!pinfo) |
313 | goto out_free_stats; |
314 | memcpy(pinfo, info, sizeof(*info)); |
315 | p->info = pinfo; |
316 | } |
317 | |
318 | dname = dev_name(ddev); |
319 | if (isdigit(dname[strlen(dname) - 1])) |
320 | dev_set_name(pdev, "%sp%d", dname, partno); |
321 | else |
322 | dev_set_name(pdev, "%s%d", dname, partno); |
323 | |
324 | device_initialize(pdev); |
325 | pdev->class = &block_class; |
326 | pdev->type = &part_type; |
327 | pdev->parent = ddev; |
328 | |
329 | err = blk_alloc_devt(p, &devt); |
330 | if (err) |
331 | goto out_free_info; |
332 | pdev->devt = devt; |
333 | |
334 | /* delay uevent until 'holders' subdir is created */ |
335 | dev_set_uevent_suppress(pdev, 1); |
336 | err = device_add(pdev); |
337 | if (err) |
338 | goto out_put; |
339 | |
340 | err = -ENOMEM; |
341 | p->holder_dir = kobject_create_and_add("holders", &pdev->kobj); |
342 | if (!p->holder_dir) |
343 | goto out_del; |
344 | |
345 | dev_set_uevent_suppress(pdev, 0); |
346 | if (flags & ADDPART_FLAG_WHOLEDISK) { |
347 | err = device_create_file(pdev, &dev_attr_whole_disk); |
348 | if (err) |
349 | goto out_del; |
350 | } |
351 | |
352 | /* everything is up and running, commence */ |
353 | rcu_assign_pointer(ptbl->part[partno], p); |
354 | |
355 | /* suppress uevent if the disk suppresses it */ |
356 | if (!dev_get_uevent_suppress(ddev)) |
357 | kobject_uevent(&pdev->kobj, KOBJ_ADD); |
358 | |
359 | hd_ref_init(p); |
360 | return p; |
361 | |
362 | out_free_info: |
363 | free_part_info(p); |
364 | out_free_stats: |
365 | free_part_stats(p); |
366 | out_free: |
367 | kfree(p); |
368 | return ERR_PTR(err); |
369 | out_del: |
370 | kobject_put(p->holder_dir); |
371 | device_del(pdev); |
372 | out_put: |
373 | put_device(pdev); |
374 | blk_free_devt(devt); |
375 | return ERR_PTR(err); |
376 | } |
377 | |
378 | static bool disk_unlock_native_capacity(struct gendisk *disk) |
379 | { |
380 | const struct block_device_operations *bdops = disk->fops; |
381 | |
382 | if (bdops->unlock_native_capacity && |
383 | !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) { |
384 | printk(KERN_CONT "enabling native capacity\n"); |
385 | bdops->unlock_native_capacity(disk); |
386 | disk->flags |= GENHD_FL_NATIVE_CAPACITY; |
387 | return true; |
388 | } else { |
389 | printk(KERN_CONT "truncated\n"); |
390 | return false; |
391 | } |
392 | } |
393 | |
394 | static int drop_partitions(struct gendisk *disk, struct block_device *bdev) |
395 | { |
396 | struct disk_part_iter piter; |
397 | struct hd_struct *part; |
398 | int res; |
399 | |
400 | if (bdev->bd_part_count) |
401 | return -EBUSY; |
402 | res = invalidate_partition(disk, 0); |
403 | if (res) |
404 | return res; |
405 | |
406 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); |
407 | while ((part = disk_part_iter_next(&piter))) |
408 | delete_partition(disk, part->partno); |
409 | disk_part_iter_exit(&piter); |
410 | |
411 | return 0; |
412 | } |
413 | |
414 | int rescan_partitions(struct gendisk *disk, struct block_device *bdev) |
415 | { |
416 | struct parsed_partitions *state = NULL; |
417 | struct hd_struct *part; |
418 | int p, highest, res; |
419 | rescan: |
420 | if (state && !IS_ERR(state)) { |
421 | free_partitions(state); |
422 | state = NULL; |
423 | } |
424 | |
425 | res = drop_partitions(disk, bdev); |
426 | if (res) |
427 | return res; |
428 | |
429 | if (disk->fops->revalidate_disk) |
430 | disk->fops->revalidate_disk(disk); |
431 | check_disk_size_change(disk, bdev); |
432 | bdev->bd_invalidated = 0; |
433 | if (!get_capacity(disk) || !(state = check_partition(disk, bdev))) |
434 | return 0; |
435 | if (IS_ERR(state)) { |
436 | /* |
437 | * I/O error reading the partition table. If any |
438 | * partition code tried to read beyond EOD, retry |
439 | * after unlocking native capacity. |
440 | */ |
441 | if (PTR_ERR(state) == -ENOSPC) { |
442 | printk(KERN_WARNING "%s: partition table beyond EOD, ", |
443 | disk->disk_name); |
444 | if (disk_unlock_native_capacity(disk)) |
445 | goto rescan; |
446 | } |
447 | return -EIO; |
448 | } |
449 | /* |
450 | * If any partition code tried to read beyond EOD, try |
451 | * unlocking native capacity even if partition table is |
452 | * successfully read as we could be missing some partitions. |
453 | */ |
454 | if (state->access_beyond_eod) { |
455 | printk(KERN_WARNING |
456 | "%s: partition table partially beyond EOD, ", |
457 | disk->disk_name); |
458 | if (disk_unlock_native_capacity(disk)) |
459 | goto rescan; |
460 | } |
461 | |
462 | /* tell userspace that the media / partition table may have changed */ |
463 | kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); |
464 | |
465 | /* Detect the highest partition number and preallocate |
466 | * disk->part_tbl. This is an optimization and not strictly |
467 | * necessary. |
468 | */ |
469 | for (p = 1, highest = 0; p < state->limit; p++) |
470 | if (state->parts[p].size) |
471 | highest = p; |
472 | |
473 | disk_expand_part_tbl(disk, highest); |
474 | |
475 | /* add partitions */ |
476 | for (p = 1; p < state->limit; p++) { |
477 | sector_t size, from; |
478 | struct partition_meta_info *info = NULL; |
479 | |
480 | size = state->parts[p].size; |
481 | if (!size) |
482 | continue; |
483 | |
484 | from = state->parts[p].from; |
485 | if (from >= get_capacity(disk)) { |
486 | printk(KERN_WARNING |
487 | "%s: p%d start %llu is beyond EOD, ", |
488 | disk->disk_name, p, (unsigned long long) from); |
489 | if (disk_unlock_native_capacity(disk)) |
490 | goto rescan; |
491 | continue; |
492 | } |
493 | |
494 | if (from + size > get_capacity(disk)) { |
495 | printk(KERN_WARNING |
496 | "%s: p%d size %llu extends beyond EOD, ", |
497 | disk->disk_name, p, (unsigned long long) size); |
498 | |
499 | if (disk_unlock_native_capacity(disk)) { |
500 | /* free state and restart */ |
501 | goto rescan; |
502 | } else { |
503 | /* |
504 | * we can not ignore partitions of broken tables |
505 | * created by for example camera firmware, but |
506 | * we limit them to the end of the disk to avoid |
507 | * creating invalid block devices |
508 | */ |
509 | size = get_capacity(disk) - from; |
510 | } |
511 | } |
512 | |
513 | if (state->parts[p].has_info) |
514 | info = &state->parts[p].info; |
515 | part = add_partition(disk, p, from, size, |
516 | state->parts[p].flags, |
517 | &state->parts[p].info); |
518 | if (IS_ERR(part)) { |
519 | printk(KERN_ERR " %s: p%d could not be added: %ld\n", |
520 | disk->disk_name, p, -PTR_ERR(part)); |
521 | continue; |
522 | } |
523 | #ifdef CONFIG_BLK_DEV_MD |
524 | if (state->parts[p].flags & ADDPART_FLAG_RAID) |
525 | md_autodetect_dev(part_to_dev(part)->devt); |
526 | #endif |
527 | } |
528 | free_partitions(state); |
529 | return 0; |
530 | } |
531 | |
532 | int invalidate_partitions(struct gendisk *disk, struct block_device *bdev) |
533 | { |
534 | int res; |
535 | |
536 | if (!bdev->bd_invalidated) |
537 | return 0; |
538 | |
539 | res = drop_partitions(disk, bdev); |
540 | if (res) |
541 | return res; |
542 | |
543 | set_capacity(disk, 0); |
544 | check_disk_size_change(disk, bdev); |
545 | bdev->bd_invalidated = 0; |
546 | /* tell userspace that the media / partition table may have changed */ |
547 | kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); |
548 | |
549 | return 0; |
550 | } |
551 | |
552 | unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) |
553 | { |
554 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
555 | struct page *page; |
556 | |
557 | page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)), |
558 | NULL); |
559 | if (!IS_ERR(page)) { |
560 | if (PageError(page)) |
561 | goto fail; |
562 | p->v = page; |
563 | return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9); |
564 | fail: |
565 | page_cache_release(page); |
566 | } |
567 | p->v = NULL; |
568 | return NULL; |
569 | } |
570 | |
571 | EXPORT_SYMBOL(read_dev_sector); |
572 |
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