1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991-1998 Linus Torvalds
4 * Re-organised Feb 1998 Russell King
7 #include <linux/slab.h>
8 #include <linux/ctype.h>
9 #include <linux/genhd.h>
10 #include <linux/vmalloc.h>
11 #include <linux/blktrace_api.h>
12 #include <linux/raid/detect.h>
15 static int (*check_part[])(struct parsed_partitions *) = {
17 * Probe partition formats with tables at disk address 0
18 * that also have an ADFS boot block at 0xdc0.
20 #ifdef CONFIG_ACORN_PARTITION_ICS
23 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
24 adfspart_check_POWERTEC,
26 #ifdef CONFIG_ACORN_PARTITION_EESOX
31 * Now move on to formats that only have partition info at
32 * disk address 0xdc0. Since these may also have stale
33 * PC/BIOS partition tables, they need to come before
36 #ifdef CONFIG_ACORN_PARTITION_CUMANA
37 adfspart_check_CUMANA,
39 #ifdef CONFIG_ACORN_PARTITION_ADFS
43 #ifdef CONFIG_CMDLINE_PARTITION
46 #ifdef CONFIG_EFI_PARTITION
47 efi_partition, /* this must come before msdos */
49 #ifdef CONFIG_SGI_PARTITION
52 #ifdef CONFIG_LDM_PARTITION
53 ldm_partition, /* this must come before msdos */
55 #ifdef CONFIG_MSDOS_PARTITION
58 #ifdef CONFIG_OSF_PARTITION
61 #ifdef CONFIG_SUN_PARTITION
64 #ifdef CONFIG_AMIGA_PARTITION
67 #ifdef CONFIG_ATARI_PARTITION
70 #ifdef CONFIG_MAC_PARTITION
73 #ifdef CONFIG_ULTRIX_PARTITION
76 #ifdef CONFIG_IBM_PARTITION
79 #ifdef CONFIG_KARMA_PARTITION
82 #ifdef CONFIG_SYSV68_PARTITION
88 static void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors)
90 spin_lock(&bdev->bd_size_lock);
91 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
92 spin_unlock(&bdev->bd_size_lock);
95 static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
97 struct parsed_partitions *state;
100 state = kzalloc(sizeof(*state), GFP_KERNEL);
104 nr = disk_max_parts(hd);
105 state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
116 static void free_partitions(struct parsed_partitions *state)
122 static struct parsed_partitions *check_partition(struct gendisk *hd,
123 struct block_device *bdev)
125 struct parsed_partitions *state;
128 state = allocate_partitions(hd);
131 state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
132 if (!state->pp_buf) {
133 free_partitions(state);
136 state->pp_buf[0] = '\0';
139 disk_name(hd, 0, state->name);
140 snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
141 if (isdigit(state->name[strlen(state->name)-1]))
142 sprintf(state->name, "p");
145 while (!res && check_part[i]) {
146 memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
147 res = check_part[i++](state);
150 * We have hit an I/O error which we don't report now.
151 * But record it, and let the others do their job.
159 printk(KERN_INFO "%s", state->pp_buf);
161 free_page((unsigned long)state->pp_buf);
164 if (state->access_beyond_eod)
167 * The partition is unrecognized. So report I/O errors if there were any
172 strlcat(state->pp_buf,
173 " unable to read partition table\n", PAGE_SIZE);
174 printk(KERN_INFO "%s", state->pp_buf);
177 free_page((unsigned long)state->pp_buf);
178 free_partitions(state);
182 static ssize_t part_partition_show(struct device *dev,
183 struct device_attribute *attr, char *buf)
185 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
188 static ssize_t part_start_show(struct device *dev,
189 struct device_attribute *attr, char *buf)
191 return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
194 static ssize_t part_ro_show(struct device *dev,
195 struct device_attribute *attr, char *buf)
197 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_read_only);
200 static ssize_t part_alignment_offset_show(struct device *dev,
201 struct device_attribute *attr, char *buf)
203 struct block_device *bdev = dev_to_bdev(dev);
205 return sprintf(buf, "%u\n",
206 queue_limit_alignment_offset(&bdev->bd_disk->queue->limits,
207 bdev->bd_start_sect));
210 static ssize_t part_discard_alignment_show(struct device *dev,
211 struct device_attribute *attr, char *buf)
213 struct block_device *bdev = dev_to_bdev(dev);
215 return sprintf(buf, "%u\n",
216 queue_limit_discard_alignment(&bdev->bd_disk->queue->limits,
217 bdev->bd_start_sect));
220 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
221 static DEVICE_ATTR(start, 0444, part_start_show, NULL);
222 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
223 static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
224 static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
225 static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
226 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
227 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
228 #ifdef CONFIG_FAIL_MAKE_REQUEST
229 static struct device_attribute dev_attr_fail =
230 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
233 static struct attribute *part_attrs[] = {
234 &dev_attr_partition.attr,
235 &dev_attr_start.attr,
238 &dev_attr_alignment_offset.attr,
239 &dev_attr_discard_alignment.attr,
241 &dev_attr_inflight.attr,
242 #ifdef CONFIG_FAIL_MAKE_REQUEST
248 static struct attribute_group part_attr_group = {
252 static const struct attribute_group *part_attr_groups[] = {
254 #ifdef CONFIG_BLK_DEV_IO_TRACE
255 &blk_trace_attr_group,
260 static void part_release(struct device *dev)
262 blk_free_devt(dev->devt);
263 bdput(dev_to_bdev(dev));
266 static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
268 struct block_device *part = dev_to_bdev(dev);
270 add_uevent_var(env, "PARTN=%u", part->bd_partno);
271 if (part->bd_meta_info && part->bd_meta_info->volname[0])
272 add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
276 struct device_type part_type = {
278 .groups = part_attr_groups,
279 .release = part_release,
280 .uevent = part_uevent,
284 * Must be called either with bd_mutex held, before a disk can be opened or
285 * after all disk users are gone.
287 void delete_partition(struct block_device *part)
289 struct gendisk *disk = part->bd_disk;
290 struct disk_part_tbl *ptbl =
291 rcu_dereference_protected(disk->part_tbl, 1);
293 rcu_assign_pointer(ptbl->part[part->bd_partno], NULL);
294 rcu_assign_pointer(ptbl->last_lookup, NULL);
296 kobject_put(part->bd_holder_dir);
297 device_del(&part->bd_device);
300 * Remove the block device from the inode hash, so that it cannot be
301 * looked up any more even when openers still hold references.
303 remove_inode_hash(part->bd_inode);
305 put_device(&part->bd_device);
308 static ssize_t whole_disk_show(struct device *dev,
309 struct device_attribute *attr, char *buf)
313 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
316 * Must be called either with bd_mutex held, before a disk can be opened or
317 * after all disk users are gone.
319 static struct block_device *add_partition(struct gendisk *disk, int partno,
320 sector_t start, sector_t len, int flags,
321 struct partition_meta_info *info)
323 dev_t devt = MKDEV(0, 0);
324 struct device *ddev = disk_to_dev(disk);
326 struct block_device *bdev;
327 struct disk_part_tbl *ptbl;
332 * Partitions are not supported on zoned block devices that are used as
335 switch (disk->queue->limits.zoned) {
337 pr_warn("%s: partitions not supported on host managed zoned block device\n",
339 return ERR_PTR(-ENXIO);
341 pr_info("%s: disabling host aware zoned block device support due to partitions\n",
343 disk->queue->limits.zoned = BLK_ZONED_NONE;
349 err = disk_expand_part_tbl(disk, partno);
352 ptbl = rcu_dereference_protected(disk->part_tbl, 1);
354 if (ptbl->part[partno])
355 return ERR_PTR(-EBUSY);
357 bdev = bdev_alloc(disk, partno);
359 return ERR_PTR(-ENOMEM);
361 bdev->bd_start_sect = start;
362 bdev_set_nr_sectors(bdev, len);
363 bdev->bd_read_only = get_disk_ro(disk);
367 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
368 if (!bdev->bd_meta_info)
372 pdev = &bdev->bd_device;
373 dname = dev_name(ddev);
374 if (isdigit(dname[strlen(dname) - 1]))
375 dev_set_name(pdev, "%sp%d", dname, partno);
377 dev_set_name(pdev, "%s%d", dname, partno);
379 device_initialize(pdev);
380 pdev->class = &block_class;
381 pdev->type = &part_type;
384 err = blk_alloc_devt(bdev, &devt);
389 /* delay uevent until 'holders' subdir is created */
390 dev_set_uevent_suppress(pdev, 1);
391 err = device_add(pdev);
396 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
397 if (!bdev->bd_holder_dir)
400 dev_set_uevent_suppress(pdev, 0);
401 if (flags & ADDPART_FLAG_WHOLEDISK) {
402 err = device_create_file(pdev, &dev_attr_whole_disk);
407 /* everything is up and running, commence */
408 bdev_add(bdev, devt);
409 rcu_assign_pointer(ptbl->part[partno], bdev);
411 /* suppress uevent if the disk suppresses it */
412 if (!dev_get_uevent_suppress(ddev))
413 kobject_uevent(&pdev->kobj, KOBJ_ADD);
420 kobject_put(bdev->bd_holder_dir);
427 static bool partition_overlaps(struct gendisk *disk, sector_t start,
428 sector_t length, int skip_partno)
430 struct disk_part_iter piter;
431 struct block_device *part;
432 bool overlap = false;
434 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
435 while ((part = disk_part_iter_next(&piter))) {
436 if (part->bd_partno == skip_partno ||
437 start >= part->bd_start_sect + bdev_nr_sectors(part) ||
438 start + length <= part->bd_start_sect)
444 disk_part_iter_exit(&piter);
448 int bdev_add_partition(struct block_device *bdev, int partno,
449 sector_t start, sector_t length)
451 struct block_device *part;
453 mutex_lock(&bdev->bd_mutex);
454 if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
455 mutex_unlock(&bdev->bd_mutex);
459 part = add_partition(bdev->bd_disk, partno, start, length,
460 ADDPART_FLAG_NONE, NULL);
461 mutex_unlock(&bdev->bd_mutex);
462 return PTR_ERR_OR_ZERO(part);
465 int bdev_del_partition(struct block_device *bdev, int partno)
467 struct block_device *part;
470 part = bdget_disk(bdev->bd_disk, partno);
474 mutex_lock(&part->bd_mutex);
475 mutex_lock_nested(&bdev->bd_mutex, 1);
478 if (part->bd_openers)
482 invalidate_bdev(part);
484 delete_partition(part);
487 mutex_unlock(&bdev->bd_mutex);
488 mutex_unlock(&part->bd_mutex);
493 int bdev_resize_partition(struct block_device *bdev, int partno,
494 sector_t start, sector_t length)
496 struct block_device *part;
499 part = bdget_disk(bdev->bd_disk, partno);
503 mutex_lock(&part->bd_mutex);
504 mutex_lock_nested(&bdev->bd_mutex, 1);
506 if (start != part->bd_start_sect)
510 if (partition_overlaps(bdev->bd_disk, start, length, partno))
513 bdev_set_nr_sectors(part, length);
517 mutex_unlock(&part->bd_mutex);
518 mutex_unlock(&bdev->bd_mutex);
523 static bool disk_unlock_native_capacity(struct gendisk *disk)
525 const struct block_device_operations *bdops = disk->fops;
527 if (bdops->unlock_native_capacity &&
528 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
529 printk(KERN_CONT "enabling native capacity\n");
530 bdops->unlock_native_capacity(disk);
531 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
534 printk(KERN_CONT "truncated\n");
539 int blk_drop_partitions(struct block_device *bdev)
541 struct disk_part_iter piter;
542 struct block_device *part;
544 if (bdev->bd_part_count)
548 invalidate_bdev(bdev);
550 disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY);
551 while ((part = disk_part_iter_next(&piter)))
552 delete_partition(part);
553 disk_part_iter_exit(&piter);
558 /* for historic reasons in the DASD driver */
559 EXPORT_SYMBOL_GPL(blk_drop_partitions);
562 static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
563 struct parsed_partitions *state, int p)
565 sector_t size = state->parts[p].size;
566 sector_t from = state->parts[p].from;
567 struct block_device *part;
572 if (from >= get_capacity(disk)) {
574 "%s: p%d start %llu is beyond EOD, ",
575 disk->disk_name, p, (unsigned long long) from);
576 if (disk_unlock_native_capacity(disk))
581 if (from + size > get_capacity(disk)) {
583 "%s: p%d size %llu extends beyond EOD, ",
584 disk->disk_name, p, (unsigned long long) size);
586 if (disk_unlock_native_capacity(disk))
590 * We can not ignore partitions of broken tables created by for
591 * example camera firmware, but we limit them to the end of the
592 * disk to avoid creating invalid block devices.
594 size = get_capacity(disk) - from;
597 part = add_partition(disk, p, from, size, state->parts[p].flags,
598 &state->parts[p].info);
599 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
600 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
601 disk->disk_name, p, -PTR_ERR(part));
605 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
606 (state->parts[p].flags & ADDPART_FLAG_RAID))
607 md_autodetect_dev(part->bd_dev);
612 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
614 struct parsed_partitions *state;
615 int ret = -EAGAIN, p, highest;
617 if (!disk_part_scan_enabled(disk))
620 state = check_partition(disk, bdev);
625 * I/O error reading the partition table. If we tried to read
626 * beyond EOD, retry after unlocking the native capacity.
628 if (PTR_ERR(state) == -ENOSPC) {
629 printk(KERN_WARNING "%s: partition table beyond EOD, ",
631 if (disk_unlock_native_capacity(disk))
638 * Partitions are not supported on host managed zoned block devices.
640 if (disk->queue->limits.zoned == BLK_ZONED_HM) {
641 pr_warn("%s: ignoring partition table on host managed zoned block device\n",
648 * If we read beyond EOD, try unlocking native capacity even if the
649 * partition table was successfully read as we could be missing some
652 if (state->access_beyond_eod) {
654 "%s: partition table partially beyond EOD, ",
656 if (disk_unlock_native_capacity(disk))
660 /* tell userspace that the media / partition table may have changed */
661 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
664 * Detect the highest partition number and preallocate disk->part_tbl.
665 * This is an optimization and not strictly necessary.
667 for (p = 1, highest = 0; p < state->limit; p++)
668 if (state->parts[p].size)
670 disk_expand_part_tbl(disk, highest);
672 for (p = 1; p < state->limit; p++)
673 if (!blk_add_partition(disk, bdev, state, p))
678 free_partitions(state);
682 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
684 struct address_space *mapping = state->bdev->bd_inode->i_mapping;
687 if (n >= get_capacity(state->bdev->bd_disk)) {
688 state->access_beyond_eod = true;
692 page = read_mapping_page(mapping,
693 (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL);
700 return (unsigned char *)page_address(page) +
701 ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT);