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