HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage()
[linux/fpc-iii.git] / block / partition-generic.c
blob29521753fb23dcbbf8605ad03592822c5aa160ec
1 /*
2 * Code extracted from drivers/block/genhd.c
3 * Copyright (C) 1991-1998 Linus Torvalds
4 * Re-organised Feb 1998 Russell King
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.
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>
21 #include "partitions/check.h"
23 #ifdef CONFIG_BLK_DEV_MD
24 extern void md_autodetect_dev(dev_t dev);
25 #endif
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).
34 char *disk_name(struct gendisk *hd, int partno, char *buf)
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);
43 return buf;
46 const char *bdevname(struct block_device *bdev, char *buf)
48 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
51 EXPORT_SYMBOL(bdevname);
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.
58 const char *__bdevname(dev_t dev, char *buffer)
60 scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
61 MAJOR(dev), MINOR(dev));
62 return buffer;
65 EXPORT_SYMBOL(__bdevname);
67 static ssize_t part_partition_show(struct device *dev,
68 struct device_attribute *attr, char *buf)
70 struct hd_struct *p = dev_to_part(dev);
72 return sprintf(buf, "%d\n", p->partno);
75 static ssize_t part_start_show(struct device *dev,
76 struct device_attribute *attr, char *buf)
78 struct hd_struct *p = dev_to_part(dev);
80 return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
83 ssize_t part_size_show(struct device *dev,
84 struct device_attribute *attr, char *buf)
86 struct hd_struct *p = dev_to_part(dev);
87 return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p));
90 static ssize_t part_ro_show(struct device *dev,
91 struct device_attribute *attr, char *buf)
93 struct hd_struct *p = dev_to_part(dev);
94 return sprintf(buf, "%d\n", p->policy ? 1 : 0);
97 static ssize_t part_alignment_offset_show(struct device *dev,
98 struct device_attribute *attr, char *buf)
100 struct hd_struct *p = dev_to_part(dev);
101 return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
104 static ssize_t part_discard_alignment_show(struct device *dev,
105 struct device_attribute *attr, char *buf)
107 struct hd_struct *p = dev_to_part(dev);
108 return sprintf(buf, "%u\n", p->discard_alignment);
111 ssize_t part_stat_show(struct device *dev,
112 struct device_attribute *attr, char *buf)
114 struct hd_struct *p = dev_to_part(dev);
115 int cpu;
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)));
138 ssize_t part_inflight_show(struct device *dev,
139 struct device_attribute *attr, char *buf)
141 struct hd_struct *p = dev_to_part(dev);
143 return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),
144 atomic_read(&p->in_flight[1]));
147 #ifdef CONFIG_FAIL_MAKE_REQUEST
148 ssize_t part_fail_show(struct device *dev,
149 struct device_attribute *attr, char *buf)
151 struct hd_struct *p = dev_to_part(dev);
153 return sprintf(buf, "%d\n", p->make_it_fail);
156 ssize_t part_fail_store(struct device *dev,
157 struct device_attribute *attr,
158 const char *buf, size_t count)
160 struct hd_struct *p = dev_to_part(dev);
161 int i;
163 if (count > 0 && sscanf(buf, "%d", &i) > 0)
164 p->make_it_fail = (i == 0) ? 0 : 1;
166 return count;
168 #endif
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
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
199 static struct attribute_group part_attr_group = {
200 .attrs = part_attrs,
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
211 static void part_release(struct device *dev)
213 struct hd_struct *p = dev_to_part(dev);
214 blk_free_devt(dev->devt);
215 hd_free_part(p);
216 kfree(p);
219 struct device_type part_type = {
220 .name = "partition",
221 .groups = part_attr_groups,
222 .release = part_release,
225 static void delete_partition_rcu_cb(struct rcu_head *head)
227 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
229 part->start_sect = 0;
230 part->nr_sects = 0;
231 part_stat_set_all(part, 0);
232 put_device(part_to_dev(part));
235 void __delete_partition(struct percpu_ref *ref)
237 struct hd_struct *part = container_of(ref, struct hd_struct, ref);
238 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
241 void delete_partition(struct gendisk *disk, int partno)
243 struct disk_part_tbl *ptbl = disk->part_tbl;
244 struct hd_struct *part;
246 if (partno >= ptbl->len)
247 return;
249 part = ptbl->part[partno];
250 if (!part)
251 return;
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));
258 hd_struct_kill(part);
261 static ssize_t whole_disk_show(struct device *dev,
262 struct device_attribute *attr, char *buf)
264 return 0;
266 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
267 whole_disk_show, NULL);
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)
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;
281 err = disk_expand_part_tbl(disk, partno);
282 if (err)
283 return ERR_PTR(err);
284 ptbl = disk->part_tbl;
286 if (ptbl->part[partno])
287 return ERR_PTR(-EBUSY);
289 p = kzalloc(sizeof(*p), GFP_KERNEL);
290 if (!p)
291 return ERR_PTR(-EBUSY);
293 if (!init_part_stats(p)) {
294 err = -ENOMEM;
295 goto out_free;
298 seqcount_init(&p->nr_sects_seq);
299 pdev = part_to_dev(p);
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);
310 if (info) {
311 struct partition_meta_info *pinfo = alloc_part_info(disk);
312 if (!pinfo) {
313 err = -ENOMEM;
314 goto out_free_stats;
316 memcpy(pinfo, info, sizeof(*info));
317 p->info = pinfo;
320 dname = dev_name(ddev);
321 if (isdigit(dname[strlen(dname) - 1]))
322 dev_set_name(pdev, "%sp%d", dname, partno);
323 else
324 dev_set_name(pdev, "%s%d", dname, partno);
326 device_initialize(pdev);
327 pdev->class = &block_class;
328 pdev->type = &part_type;
329 pdev->parent = ddev;
331 err = blk_alloc_devt(p, &devt);
332 if (err)
333 goto out_free_info;
334 pdev->devt = devt;
336 /* delay uevent until 'holders' subdir is created */
337 dev_set_uevent_suppress(pdev, 1);
338 err = device_add(pdev);
339 if (err)
340 goto out_put;
342 err = -ENOMEM;
343 p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
344 if (!p->holder_dir)
345 goto out_del;
347 dev_set_uevent_suppress(pdev, 0);
348 if (flags & ADDPART_FLAG_WHOLEDISK) {
349 err = device_create_file(pdev, &dev_attr_whole_disk);
350 if (err)
351 goto out_del;
354 err = hd_ref_init(p);
355 if (err) {
356 if (flags & ADDPART_FLAG_WHOLEDISK)
357 goto out_remove_file;
358 goto out_del;
361 /* everything is up and running, commence */
362 rcu_assign_pointer(ptbl->part[partno], p);
364 /* suppress uevent if the disk suppresses it */
365 if (!dev_get_uevent_suppress(ddev))
366 kobject_uevent(&pdev->kobj, KOBJ_ADD);
367 return p;
369 out_free_info:
370 free_part_info(p);
371 out_free_stats:
372 free_part_stats(p);
373 out_free:
374 kfree(p);
375 return ERR_PTR(err);
376 out_remove_file:
377 device_remove_file(pdev, &dev_attr_whole_disk);
378 out_del:
379 kobject_put(p->holder_dir);
380 device_del(pdev);
381 out_put:
382 put_device(pdev);
383 blk_free_devt(devt);
384 return ERR_PTR(err);
387 static bool disk_unlock_native_capacity(struct gendisk *disk)
389 const struct block_device_operations *bdops = disk->fops;
391 if (bdops->unlock_native_capacity &&
392 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
393 printk(KERN_CONT "enabling native capacity\n");
394 bdops->unlock_native_capacity(disk);
395 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
396 return true;
397 } else {
398 printk(KERN_CONT "truncated\n");
399 return false;
403 static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
405 struct disk_part_iter piter;
406 struct hd_struct *part;
407 int res;
409 if (bdev->bd_part_count || bdev->bd_super)
410 return -EBUSY;
411 res = invalidate_partition(disk, 0);
412 if (res)
413 return res;
415 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
416 while ((part = disk_part_iter_next(&piter)))
417 delete_partition(disk, part->partno);
418 disk_part_iter_exit(&piter);
420 return 0;
423 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
425 struct parsed_partitions *state = NULL;
426 struct hd_struct *part;
427 int p, highest, res;
428 rescan:
429 if (state && !IS_ERR(state)) {
430 free_partitions(state);
431 state = NULL;
434 res = drop_partitions(disk, bdev);
435 if (res)
436 return res;
438 if (disk->fops->revalidate_disk)
439 disk->fops->revalidate_disk(disk);
440 check_disk_size_change(disk, bdev);
441 bdev->bd_invalidated = 0;
442 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
443 return 0;
444 if (IS_ERR(state)) {
446 * I/O error reading the partition table. If any
447 * partition code tried to read beyond EOD, retry
448 * after unlocking native capacity.
450 if (PTR_ERR(state) == -ENOSPC) {
451 printk(KERN_WARNING "%s: partition table beyond EOD, ",
452 disk->disk_name);
453 if (disk_unlock_native_capacity(disk))
454 goto rescan;
456 return -EIO;
459 * If any partition code tried to read beyond EOD, try
460 * unlocking native capacity even if partition table is
461 * successfully read as we could be missing some partitions.
463 if (state->access_beyond_eod) {
464 printk(KERN_WARNING
465 "%s: partition table partially beyond EOD, ",
466 disk->disk_name);
467 if (disk_unlock_native_capacity(disk))
468 goto rescan;
471 /* tell userspace that the media / partition table may have changed */
472 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
474 /* Detect the highest partition number and preallocate
475 * disk->part_tbl. This is an optimization and not strictly
476 * necessary.
478 for (p = 1, highest = 0; p < state->limit; p++)
479 if (state->parts[p].size)
480 highest = p;
482 disk_expand_part_tbl(disk, highest);
484 /* add partitions */
485 for (p = 1; p < state->limit; p++) {
486 sector_t size, from;
487 struct partition_meta_info *info = NULL;
489 size = state->parts[p].size;
490 if (!size)
491 continue;
493 from = state->parts[p].from;
494 if (from >= get_capacity(disk)) {
495 printk(KERN_WARNING
496 "%s: p%d start %llu is beyond EOD, ",
497 disk->disk_name, p, (unsigned long long) from);
498 if (disk_unlock_native_capacity(disk))
499 goto rescan;
500 continue;
503 if (from + size > get_capacity(disk)) {
504 printk(KERN_WARNING
505 "%s: p%d size %llu extends beyond EOD, ",
506 disk->disk_name, p, (unsigned long long) size);
508 if (disk_unlock_native_capacity(disk)) {
509 /* free state and restart */
510 goto rescan;
511 } else {
513 * we can not ignore partitions of broken tables
514 * created by for example camera firmware, but
515 * we limit them to the end of the disk to avoid
516 * creating invalid block devices
518 size = get_capacity(disk) - from;
522 if (state->parts[p].has_info)
523 info = &state->parts[p].info;
524 part = add_partition(disk, p, from, size,
525 state->parts[p].flags,
526 &state->parts[p].info);
527 if (IS_ERR(part)) {
528 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
529 disk->disk_name, p, -PTR_ERR(part));
530 continue;
532 #ifdef CONFIG_BLK_DEV_MD
533 if (state->parts[p].flags & ADDPART_FLAG_RAID)
534 md_autodetect_dev(part_to_dev(part)->devt);
535 #endif
537 free_partitions(state);
538 return 0;
541 int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
543 int res;
545 if (!bdev->bd_invalidated)
546 return 0;
548 res = drop_partitions(disk, bdev);
549 if (res)
550 return res;
552 set_capacity(disk, 0);
553 check_disk_size_change(disk, bdev);
554 bdev->bd_invalidated = 0;
555 /* tell userspace that the media / partition table may have changed */
556 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
558 return 0;
561 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
563 struct address_space *mapping = bdev->bd_inode->i_mapping;
564 struct page *page;
566 page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
567 NULL);
568 if (!IS_ERR(page)) {
569 if (PageError(page))
570 goto fail;
571 p->v = page;
572 return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
573 fail:
574 page_cache_release(page);
576 p->v = NULL;
577 return NULL;
580 EXPORT_SYMBOL(read_dev_sector);