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1 /*
2 * fs/partitions/check.c
3 *
4 * Code extracted from drivers/block/genhd.c
5 * Copyright (C) 1991-1998 Linus Torvalds
6 * Re-organised Feb 1998 Russell King
7 *
8 * We now have independent partition support from the
9 * block drivers, which allows all the partition code to
10 * be grouped in one location, and it to be mostly self
11 * contained.
12 *
13 * Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
14 */
15
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/kmod.h>
20 #include <linux/ctype.h>
21 #include <linux/genhd.h>
22 #include <linux/blktrace_api.h>
23
24 #include "check.h"
25
26 #include "acorn.h"
27 #include "amiga.h"
28 #include "atari.h"
29 #include "ldm.h"
30 #include "mac.h"
31 #include "msdos.h"
32 #include "osf.h"
33 #include "sgi.h"
34 #include "sun.h"
35 #include "ibm.h"
36 #include "ultrix.h"
37 #include "efi.h"
38 #include "karma.h"
39 #include "sysv68.h"
40
41 #ifdef CONFIG_BLK_DEV_MD
42 extern void md_autodetect_dev(dev_t dev);
43 #endif
44
45 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
46
47 static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
48 /*
49 * Probe partition formats with tables at disk address 0
50 * that also have an ADFS boot block at 0xdc0.
51 */
52 #ifdef CONFIG_ACORN_PARTITION_ICS
53 adfspart_check_ICS,
54 #endif
55 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
56 adfspart_check_POWERTEC,
57 #endif
58 #ifdef CONFIG_ACORN_PARTITION_EESOX
59 adfspart_check_EESOX,
60 #endif
61
62 /*
63 * Now move on to formats that only have partition info at
64 * disk address 0xdc0. Since these may also have stale
65 * PC/BIOS partition tables, they need to come before
66 * the msdos entry.
67 */
68 #ifdef CONFIG_ACORN_PARTITION_CUMANA
69 adfspart_check_CUMANA,
70 #endif
71 #ifdef CONFIG_ACORN_PARTITION_ADFS
72 adfspart_check_ADFS,
73 #endif
74
75 #ifdef CONFIG_EFI_PARTITION
76 efi_partition, /* this must come before msdos */
77 #endif
78 #ifdef CONFIG_SGI_PARTITION
79 sgi_partition,
80 #endif
81 #ifdef CONFIG_LDM_PARTITION
82 ldm_partition, /* this must come before msdos */
83 #endif
84 #ifdef CONFIG_MSDOS_PARTITION
85 msdos_partition,
86 #endif
87 #ifdef CONFIG_OSF_PARTITION
88 osf_partition,
89 #endif
90 #ifdef CONFIG_SUN_PARTITION
91 sun_partition,
92 #endif
93 #ifdef CONFIG_AMIGA_PARTITION
94 amiga_partition,
95 #endif
96 #ifdef CONFIG_ATARI_PARTITION
97 atari_partition,
98 #endif
99 #ifdef CONFIG_MAC_PARTITION
100 mac_partition,
101 #endif
102 #ifdef CONFIG_ULTRIX_PARTITION
103 ultrix_partition,
104 #endif
105 #ifdef CONFIG_IBM_PARTITION
106 ibm_partition,
107 #endif
108 #ifdef CONFIG_KARMA_PARTITION
109 karma_partition,
110 #endif
111 #ifdef CONFIG_SYSV68_PARTITION
112 sysv68_partition,
113 #endif
114 NULL
115 };
116
117 /*
118 * disk_name() is used by partition check code and the genhd driver.
119 * It formats the devicename of the indicated disk into
120 * the supplied buffer (of size at least 32), and returns
121 * a pointer to that same buffer (for convenience).
122 */
123
124 char *disk_name(struct gendisk *hd, int partno, char *buf)
125 {
126 if (!partno)
127 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
128 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
129 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
130 else
131 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
132
133 return buf;
134 }
135
136 const char *bdevname(struct block_device *bdev, char *buf)
137 {
138 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
139 }
140
141 EXPORT_SYMBOL(bdevname);
142
143 /*
144 * There's very little reason to use this, you should really
145 * have a struct block_device just about everywhere and use
146 * bdevname() instead.
147 */
148 const char *__bdevname(dev_t dev, char *buffer)
149 {
150 scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
151 MAJOR(dev), MINOR(dev));
152 return buffer;
153 }
154
155 EXPORT_SYMBOL(__bdevname);
156
157 static struct parsed_partitions *
158 check_partition(struct gendisk *hd, struct block_device *bdev)
159 {
160 struct parsed_partitions *state;
161 int i, res, err;
162
163 state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
164 if (!state)
165 return NULL;
166
167 disk_name(hd, 0, state->name);
168 printk(KERN_INFO " %s:", state->name);
169 if (isdigit(state->name[strlen(state->name)-1]))
170 sprintf(state->name, "p");
171
172 state->limit = disk_max_parts(hd);
173 i = res = err = 0;
174 while (!res && check_part[i]) {
175 memset(&state->parts, 0, sizeof(state->parts));
176 res = check_part[i++](state, bdev);
177 if (res < 0) {
178 /* We have hit an I/O error which we don't report now.
179 * But record it, and let the others do their job.
180 */
181 err = res;
182 res = 0;
183 }
184
185 }
186 if (res > 0)
187 return state;
188 if (err)
189 /* The partition is unrecognized. So report I/O errors if there were any */
190 res = err;
191 if (!res)
192 printk(" unknown partition table\n");
193 else if (warn_no_part)
194 printk(" unable to read partition table\n");
195 kfree(state);
196 return ERR_PTR(res);
197 }
198
199 static ssize_t part_partition_show(struct device *dev,
200 struct device_attribute *attr, char *buf)
201 {
202 struct hd_struct *p = dev_to_part(dev);
203
204 return sprintf(buf, "%d\n", p->partno);
205 }
206
207 static ssize_t part_start_show(struct device *dev,
208 struct device_attribute *attr, char *buf)
209 {
210 struct hd_struct *p = dev_to_part(dev);
211
212 return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
213 }
214
215 ssize_t part_size_show(struct device *dev,
216 struct device_attribute *attr, char *buf)
217 {
218 struct hd_struct *p = dev_to_part(dev);
219 return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
220 }
221
222 ssize_t part_alignment_offset_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
224 {
225 struct hd_struct *p = dev_to_part(dev);
226 return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
227 }
228
229 ssize_t part_discard_alignment_show(struct device *dev,
230 struct device_attribute *attr, char *buf)
231 {
232 struct hd_struct *p = dev_to_part(dev);
233 return sprintf(buf, "%u\n", p->discard_alignment);
234 }
235
236 ssize_t part_stat_show(struct device *dev,
237 struct device_attribute *attr, char *buf)
238 {
239 struct hd_struct *p = dev_to_part(dev);
240 int cpu;
241
242 cpu = part_stat_lock();
243 part_round_stats(cpu, p);
244 part_stat_unlock();
245 return sprintf(buf,
246 "%8lu %8lu %8llu %8u "
247 "%8lu %8lu %8llu %8u "
248 "%8u %8u %8u"
249 "\n",
250 part_stat_read(p, ios[READ]),
251 part_stat_read(p, merges[READ]),
252 (unsigned long long)part_stat_read(p, sectors[READ]),
253 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
254 part_stat_read(p, ios[WRITE]),
255 part_stat_read(p, merges[WRITE]),
256 (unsigned long long)part_stat_read(p, sectors[WRITE]),
257 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
258 part_in_flight(p),
259 jiffies_to_msecs(part_stat_read(p, io_ticks)),
260 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
261 }
262
263 ssize_t part_inflight_show(struct device *dev,
264 struct device_attribute *attr, char *buf)
265 {
266 struct hd_struct *p = dev_to_part(dev);
267
268 return sprintf(buf, "%8u %8u\n", p->in_flight[0], p->in_flight[1]);
269 }
270
271 #ifdef CONFIG_FAIL_MAKE_REQUEST
272 ssize_t part_fail_show(struct device *dev,
273 struct device_attribute *attr, char *buf)
274 {
275 struct hd_struct *p = dev_to_part(dev);
276
277 return sprintf(buf, "%d\n", p->make_it_fail);
278 }
279
280 ssize_t part_fail_store(struct device *dev,
281 struct device_attribute *attr,
282 const char *buf, size_t count)
283 {
284 struct hd_struct *p = dev_to_part(dev);
285 int i;
286
287 if (count > 0 && sscanf(buf, "%d", &i) > 0)
288 p->make_it_fail = (i == 0) ? 0 : 1;
289
290 return count;
291 }
292 #endif
293
294 static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
295 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
296 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
297 static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
298 static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
299 NULL);
300 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
301 static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
302 #ifdef CONFIG_FAIL_MAKE_REQUEST
303 static struct device_attribute dev_attr_fail =
304 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
305 #endif
306
307 static struct attribute *part_attrs[] = {
308 &dev_attr_partition.attr,
309 &dev_attr_start.attr,
310 &dev_attr_size.attr,
311 &dev_attr_alignment_offset.attr,
312 &dev_attr_discard_alignment.attr,
313 &dev_attr_stat.attr,
314 &dev_attr_inflight.attr,
315 #ifdef CONFIG_FAIL_MAKE_REQUEST
316 &dev_attr_fail.attr,
317 #endif
318 NULL
319 };
320
321 static struct attribute_group part_attr_group = {
322 .attrs = part_attrs,
323 };
324
325 static const struct attribute_group *part_attr_groups[] = {
326 &part_attr_group,
327 #ifdef CONFIG_BLK_DEV_IO_TRACE
328 &blk_trace_attr_group,
329 #endif
330 NULL
331 };
332
333 static void part_release(struct device *dev)
334 {
335 struct hd_struct *p = dev_to_part(dev);
336 free_part_stats(p);
337 kfree(p);
338 }
339
340 struct device_type part_type = {
341 .name = "partition",
342 .groups = part_attr_groups,
343 .release = part_release,
344 };
345
346 static void delete_partition_rcu_cb(struct rcu_head *head)
347 {
348 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
349
350 part->start_sect = 0;
351 part->nr_sects = 0;
352 part_stat_set_all(part, 0);
353 put_device(part_to_dev(part));
354 }
355
356 void delete_partition(struct gendisk *disk, int partno)
357 {
358 struct disk_part_tbl *ptbl = disk->part_tbl;
359 struct hd_struct *part;
360
361 if (partno >= ptbl->len)
362 return;
363
364 part = ptbl->part[partno];
365 if (!part)
366 return;
367
368 blk_free_devt(part_devt(part));
369 rcu_assign_pointer(ptbl->part[partno], NULL);
370 rcu_assign_pointer(ptbl->last_lookup, NULL);
371 kobject_put(part->holder_dir);
372 device_del(part_to_dev(part));
373
374 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
375 }
376
377 static ssize_t whole_disk_show(struct device *dev,
378 struct device_attribute *attr, char *buf)
379 {
380 return 0;
381 }
382 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
383 whole_disk_show, NULL);
384
385 struct hd_struct *add_partition(struct gendisk *disk, int partno,
386 sector_t start, sector_t len, int flags)
387 {
388 struct hd_struct *p;
389 dev_t devt = MKDEV(0, 0);
390 struct device *ddev = disk_to_dev(disk);
391 struct device *pdev;
392 struct disk_part_tbl *ptbl;
393 const char *dname;
394 int err;
395
396 err = disk_expand_part_tbl(disk, partno);
397 if (err)
398 return ERR_PTR(err);
399 ptbl = disk->part_tbl;
400
401 if (ptbl->part[partno])
402 return ERR_PTR(-EBUSY);
403
404 p = kzalloc(sizeof(*p), GFP_KERNEL);
405 if (!p)
406 return ERR_PTR(-EBUSY);
407
408 if (!init_part_stats(p)) {
409 err = -ENOMEM;
410 goto out_free;
411 }
412 pdev = part_to_dev(p);
413
414 p->start_sect = start;
415 p->alignment_offset =
416 queue_limit_alignment_offset(&disk->queue->limits, start);
417 p->discard_alignment =
418 queue_limit_discard_alignment(&disk->queue->limits, start);
419 p->nr_sects = len;
420 p->partno = partno;
421 p->policy = get_disk_ro(disk);
422
423 dname = dev_name(ddev);
424 if (isdigit(dname[strlen(dname) - 1]))
425 dev_set_name(pdev, "%sp%d", dname, partno);
426 else
427 dev_set_name(pdev, "%s%d", dname, partno);
428
429 device_initialize(pdev);
430 pdev->class = &block_class;
431 pdev->type = &part_type;
432 pdev->parent = ddev;
433
434 err = blk_alloc_devt(p, &devt);
435 if (err)
436 goto out_free_stats;
437 pdev->devt = devt;
438
439 /* delay uevent until 'holders' subdir is created */
440 dev_set_uevent_suppress(pdev, 1);
441 err = device_add(pdev);
442 if (err)
443 goto out_put;
444
445 err = -ENOMEM;
446 p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
447 if (!p->holder_dir)
448 goto out_del;
449
450 dev_set_uevent_suppress(pdev, 0);
451 if (flags & ADDPART_FLAG_WHOLEDISK) {
452 err = device_create_file(pdev, &dev_attr_whole_disk);
453 if (err)
454 goto out_del;
455 }
456
457 /* everything is up and running, commence */
458 INIT_RCU_HEAD(&p->rcu_head);
459 rcu_assign_pointer(ptbl->part[partno], p);
460
461 /* suppress uevent if the disk supresses it */
462 if (!dev_get_uevent_suppress(ddev))
463 kobject_uevent(&pdev->kobj, KOBJ_ADD);
464
465 return p;
466
467 out_free_stats:
468 free_part_stats(p);
469 out_free:
470 kfree(p);
471 return ERR_PTR(err);
472 out_del:
473 kobject_put(p->holder_dir);
474 device_del(pdev);
475 out_put:
476 put_device(pdev);
477 blk_free_devt(devt);
478 return ERR_PTR(err);
479 }
480
481 /* Not exported, helper to add_disk(). */
482 void register_disk(struct gendisk *disk)
483 {
484 struct device *ddev = disk_to_dev(disk);
485 struct block_device *bdev;
486 struct disk_part_iter piter;
487 struct hd_struct *part;
488 int err;
489
490 ddev->parent = disk->driverfs_dev;
491
492 dev_set_name(ddev, disk->disk_name);
493
494 /* delay uevents, until we scanned partition table */
495 dev_set_uevent_suppress(ddev, 1);
496
497 if (device_add(ddev))
498 return;
499 #ifndef CONFIG_SYSFS_DEPRECATED
500 err = sysfs_create_link(block_depr, &ddev->kobj,
501 kobject_name(&ddev->kobj));
502 if (err) {
503 device_del(ddev);
504 return;
505 }
506 #endif
507 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
508 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
509
510 /* No minors to use for partitions */
511 if (!disk_partitionable(disk))
512 goto exit;
513
514 /* No such device (e.g., media were just removed) */
515 if (!get_capacity(disk))
516 goto exit;
517
518 bdev = bdget_disk(disk, 0);
519 if (!bdev)
520 goto exit;
521
522 bdev->bd_invalidated = 1;
523 err = blkdev_get(bdev, FMODE_READ);
524 if (err < 0)
525 goto exit;
526 blkdev_put(bdev, FMODE_READ);
527
528 exit:
529 /* announce disk after possible partitions are created */
530 dev_set_uevent_suppress(ddev, 0);
531 kobject_uevent(&ddev->kobj, KOBJ_ADD);
532
533 /* announce possible partitions */
534 disk_part_iter_init(&piter, disk, 0);
535 while ((part = disk_part_iter_next(&piter)))
536 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
537 disk_part_iter_exit(&piter);
538 }
539
540 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
541 {
542 struct disk_part_iter piter;
543 struct hd_struct *part;
544 struct parsed_partitions *state;
545 int p, highest, res;
546
547 if (bdev->bd_part_count)
548 return -EBUSY;
549 res = invalidate_partition(disk, 0);
550 if (res)
551 return res;
552
553 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
554 while ((part = disk_part_iter_next(&piter)))
555 delete_partition(disk, part->partno);
556 disk_part_iter_exit(&piter);
557
558 if (disk->fops->revalidate_disk)
559 disk->fops->revalidate_disk(disk);
560 check_disk_size_change(disk, bdev);
561 bdev->bd_invalidated = 0;
562 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
563 return 0;
564 if (IS_ERR(state)) /* I/O error reading the partition table */
565 return -EIO;
566
567 /* tell userspace that the media / partition table may have changed */
568 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
569
570 /* Detect the highest partition number and preallocate
571 * disk->part_tbl. This is an optimization and not strictly
572 * necessary.
573 */
574 for (p = 1, highest = 0; p < state->limit; p++)
575 if (state->parts[p].size)
576 highest = p;
577
578 disk_expand_part_tbl(disk, highest);
579
580 /* add partitions */
581 for (p = 1; p < state->limit; p++) {
582 sector_t size, from;
583 try_scan:
584 size = state->parts[p].size;
585 if (!size)
586 continue;
587
588 from = state->parts[p].from;
589 if (from >= get_capacity(disk)) {
590 printk(KERN_WARNING
591 "%s: p%d ignored, start %llu is behind the end of the disk\n",
592 disk->disk_name, p, (unsigned long long) from);
593 continue;
594 }
595
596 if (from + size > get_capacity(disk)) {
597 const struct block_device_operations *bdops = disk->fops;
598 unsigned long long capacity;
599
600 printk(KERN_WARNING
601 "%s: p%d size %llu exceeds device capacity, ",
602 disk->disk_name, p, (unsigned long long) size);
603
604 if (bdops->set_capacity &&
605 (disk->flags & GENHD_FL_NATIVE_CAPACITY) == 0) {
606 printk(KERN_CONT "enabling native capacity\n");
607 capacity = bdops->set_capacity(disk, ~0ULL);
608 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
609 if (capacity > get_capacity(disk)) {
610 set_capacity(disk, capacity);
611 check_disk_size_change(disk, bdev);
612 bdev->bd_invalidated = 0;
613 }
614 goto try_scan;
615 } else {
616 /*
617 * we can not ignore partitions of broken tables
618 * created by for example camera firmware, but
619 * we limit them to the end of the disk to avoid
620 * creating invalid block devices
621 */
622 printk(KERN_CONT "limited to end of disk\n");
623 size = get_capacity(disk) - from;
624 }
625 }
626 part = add_partition(disk, p, from, size,
627 state->parts[p].flags);
628 if (IS_ERR(part)) {
629 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
630 disk->disk_name, p, -PTR_ERR(part));
631 continue;
632 }
633 #ifdef CONFIG_BLK_DEV_MD
634 if (state->parts[p].flags & ADDPART_FLAG_RAID)
635 md_autodetect_dev(part_to_dev(part)->devt);
636 #endif
637 }
638 kfree(state);
639 return 0;
640 }
641
642 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
643 {
644 struct address_space *mapping = bdev->bd_inode->i_mapping;
645 struct page *page;
646
647 page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
648 NULL);
649 if (!IS_ERR(page)) {
650 if (PageError(page))
651 goto fail;
652 p->v = page;
653 return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
654 fail:
655 page_cache_release(page);
656 }
657 p->v = NULL;
658 return NULL;
659 }
660
661 EXPORT_SYMBOL(read_dev_sector);
662
663 void del_gendisk(struct gendisk *disk)
664 {
665 struct disk_part_iter piter;
666 struct hd_struct *part;
667
668 /* invalidate stuff */
669 disk_part_iter_init(&piter, disk,
670 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
671 while ((part = disk_part_iter_next(&piter))) {
672 invalidate_partition(disk, part->partno);
673 delete_partition(disk, part->partno);
674 }
675 disk_part_iter_exit(&piter);
676
677 invalidate_partition(disk, 0);
678 blk_free_devt(disk_to_dev(disk)->devt);
679 set_capacity(disk, 0);
680 disk->flags &= ~GENHD_FL_UP;
681 unlink_gendisk(disk);
682 part_stat_set_all(&disk->part0, 0);
683 disk->part0.stamp = 0;
684
685 kobject_put(disk->part0.holder_dir);
686 kobject_put(disk->slave_dir);
687 disk->driverfs_dev = NULL;
688 #ifndef CONFIG_SYSFS_DEPRECATED
689 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
690 #endif
691 device_del(disk_to_dev(disk));
692 }