1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 1991-1998 Linus Torvalds
4 * Re-organised Feb 1998 Russell King
5 * Copyright (C) 2020 Christoph Hellwig
8 #include <linux/slab.h>
9 #include <linux/ctype.h>
10 #include <linux/genhd.h>
11 #include <linux/vmalloc.h>
12 #include <linux/blktrace_api.h>
13 #include <linux/raid/detect.h>
16 static int (*check_part[])(struct parsed_partitions *) = {
18 * Probe partition formats with tables at disk address 0
19 * that also have an ADFS boot block at 0xdc0.
21 #ifdef CONFIG_ACORN_PARTITION_ICS
24 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
25 adfspart_check_POWERTEC,
27 #ifdef CONFIG_ACORN_PARTITION_EESOX
32 * Now move on to formats that only have partition info at
33 * disk address 0xdc0. Since these may also have stale
34 * PC/BIOS partition tables, they need to come before
37 #ifdef CONFIG_ACORN_PARTITION_CUMANA
38 adfspart_check_CUMANA,
40 #ifdef CONFIG_ACORN_PARTITION_ADFS
44 #ifdef CONFIG_CMDLINE_PARTITION
47 #ifdef CONFIG_EFI_PARTITION
48 efi_partition, /* this must come before msdos */
50 #ifdef CONFIG_SGI_PARTITION
53 #ifdef CONFIG_LDM_PARTITION
54 ldm_partition, /* this must come before msdos */
56 #ifdef CONFIG_MSDOS_PARTITION
59 #ifdef CONFIG_OSF_PARTITION
62 #ifdef CONFIG_SUN_PARTITION
65 #ifdef CONFIG_AMIGA_PARTITION
68 #ifdef CONFIG_ATARI_PARTITION
71 #ifdef CONFIG_MAC_PARTITION
74 #ifdef CONFIG_ULTRIX_PARTITION
77 #ifdef CONFIG_IBM_PARTITION
80 #ifdef CONFIG_KARMA_PARTITION
83 #ifdef CONFIG_SYSV68_PARTITION
89 static void bdev_set_nr_sectors(struct block_device *bdev, sector_t sectors)
93 spin_lock_irqsave(&bdev->bd_size_lock, flags);
94 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
95 spin_unlock_irqrestore(&bdev->bd_size_lock, flags);
98 static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
100 struct parsed_partitions *state;
103 state = kzalloc(sizeof(*state), GFP_KERNEL);
107 nr = disk_max_parts(hd);
108 state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
119 static void free_partitions(struct parsed_partitions *state)
125 static struct parsed_partitions *check_partition(struct gendisk *hd,
126 struct block_device *bdev)
128 struct parsed_partitions *state;
131 state = allocate_partitions(hd);
134 state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
135 if (!state->pp_buf) {
136 free_partitions(state);
139 state->pp_buf[0] = '\0';
142 disk_name(hd, 0, state->name);
143 snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
144 if (isdigit(state->name[strlen(state->name)-1]))
145 sprintf(state->name, "p");
148 while (!res && check_part[i]) {
149 memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
150 res = check_part[i++](state);
153 * We have hit an I/O error which we don't report now.
154 * But record it, and let the others do their job.
162 printk(KERN_INFO "%s", state->pp_buf);
164 free_page((unsigned long)state->pp_buf);
167 if (state->access_beyond_eod)
170 * The partition is unrecognized. So report I/O errors if there were any
175 strlcat(state->pp_buf,
176 " unable to read partition table\n", PAGE_SIZE);
177 printk(KERN_INFO "%s", state->pp_buf);
180 free_page((unsigned long)state->pp_buf);
181 free_partitions(state);
185 static ssize_t part_partition_show(struct device *dev,
186 struct device_attribute *attr, char *buf)
188 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
191 static ssize_t part_start_show(struct device *dev,
192 struct device_attribute *attr, char *buf)
194 return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
197 static ssize_t part_ro_show(struct device *dev,
198 struct device_attribute *attr, char *buf)
200 return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev)));
203 static ssize_t part_alignment_offset_show(struct device *dev,
204 struct device_attribute *attr, char *buf)
206 struct block_device *bdev = dev_to_bdev(dev);
208 return sprintf(buf, "%u\n",
209 queue_limit_alignment_offset(&bdev->bd_disk->queue->limits,
210 bdev->bd_start_sect));
213 static ssize_t part_discard_alignment_show(struct device *dev,
214 struct device_attribute *attr, char *buf)
216 struct block_device *bdev = dev_to_bdev(dev);
218 return sprintf(buf, "%u\n",
219 queue_limit_discard_alignment(&bdev->bd_disk->queue->limits,
220 bdev->bd_start_sect));
223 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
224 static DEVICE_ATTR(start, 0444, part_start_show, NULL);
225 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
226 static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
227 static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
228 static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
229 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
230 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
231 #ifdef CONFIG_FAIL_MAKE_REQUEST
232 static struct device_attribute dev_attr_fail =
233 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
236 static struct attribute *part_attrs[] = {
237 &dev_attr_partition.attr,
238 &dev_attr_start.attr,
241 &dev_attr_alignment_offset.attr,
242 &dev_attr_discard_alignment.attr,
244 &dev_attr_inflight.attr,
245 #ifdef CONFIG_FAIL_MAKE_REQUEST
251 static struct attribute_group part_attr_group = {
255 static const struct attribute_group *part_attr_groups[] = {
257 #ifdef CONFIG_BLK_DEV_IO_TRACE
258 &blk_trace_attr_group,
263 static void part_release(struct device *dev)
265 blk_free_devt(dev->devt);
266 bdput(dev_to_bdev(dev));
269 static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
271 struct block_device *part = dev_to_bdev(dev);
273 add_uevent_var(env, "PARTN=%u", part->bd_partno);
274 if (part->bd_meta_info && part->bd_meta_info->volname[0])
275 add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
279 struct device_type part_type = {
281 .groups = part_attr_groups,
282 .release = part_release,
283 .uevent = part_uevent,
287 * Must be called either with bd_mutex held, before a disk can be opened or
288 * after all disk users are gone.
290 void delete_partition(struct block_device *part)
292 xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
293 kobject_put(part->bd_holder_dir);
294 device_del(&part->bd_device);
297 * Remove the block device from the inode hash, so that it cannot be
298 * looked up any more even when openers still hold references.
300 remove_inode_hash(part->bd_inode);
302 put_device(&part->bd_device);
305 static ssize_t whole_disk_show(struct device *dev,
306 struct device_attribute *attr, char *buf)
310 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
313 * Must be called either with bd_mutex held, before a disk can be opened or
314 * after all disk users are gone.
316 static struct block_device *add_partition(struct gendisk *disk, int partno,
317 sector_t start, sector_t len, int flags,
318 struct partition_meta_info *info)
320 dev_t devt = MKDEV(0, 0);
321 struct device *ddev = disk_to_dev(disk);
323 struct block_device *bdev;
328 * Partitions are not supported on zoned block devices that are used as
331 switch (disk->queue->limits.zoned) {
333 pr_warn("%s: partitions not supported on host managed zoned block device\n",
335 return ERR_PTR(-ENXIO);
337 pr_info("%s: disabling host aware zoned block device support due to partitions\n",
339 blk_queue_set_zoned(disk, BLK_ZONED_NONE);
345 if (xa_load(&disk->part_tbl, partno))
346 return ERR_PTR(-EBUSY);
348 bdev = bdev_alloc(disk, partno);
350 return ERR_PTR(-ENOMEM);
352 bdev->bd_start_sect = start;
353 bdev_set_nr_sectors(bdev, len);
357 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
358 if (!bdev->bd_meta_info)
362 pdev = &bdev->bd_device;
363 dname = dev_name(ddev);
364 if (isdigit(dname[strlen(dname) - 1]))
365 dev_set_name(pdev, "%sp%d", dname, partno);
367 dev_set_name(pdev, "%s%d", dname, partno);
369 device_initialize(pdev);
370 pdev->class = &block_class;
371 pdev->type = &part_type;
374 err = blk_alloc_devt(bdev, &devt);
379 /* delay uevent until 'holders' subdir is created */
380 dev_set_uevent_suppress(pdev, 1);
381 err = device_add(pdev);
386 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
387 if (!bdev->bd_holder_dir)
390 dev_set_uevent_suppress(pdev, 0);
391 if (flags & ADDPART_FLAG_WHOLEDISK) {
392 err = device_create_file(pdev, &dev_attr_whole_disk);
397 /* everything is up and running, commence */
398 err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
401 bdev_add(bdev, devt);
403 /* suppress uevent if the disk suppresses it */
404 if (!dev_get_uevent_suppress(ddev))
405 kobject_uevent(&pdev->kobj, KOBJ_ADD);
412 kobject_put(bdev->bd_holder_dir);
419 static bool partition_overlaps(struct gendisk *disk, sector_t start,
420 sector_t length, int skip_partno)
422 struct disk_part_iter piter;
423 struct block_device *part;
424 bool overlap = false;
426 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
427 while ((part = disk_part_iter_next(&piter))) {
428 if (part->bd_partno == skip_partno ||
429 start >= part->bd_start_sect + bdev_nr_sectors(part) ||
430 start + length <= part->bd_start_sect)
436 disk_part_iter_exit(&piter);
440 int bdev_add_partition(struct block_device *bdev, int partno,
441 sector_t start, sector_t length)
443 struct block_device *part;
445 mutex_lock(&bdev->bd_mutex);
446 if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
447 mutex_unlock(&bdev->bd_mutex);
451 part = add_partition(bdev->bd_disk, partno, start, length,
452 ADDPART_FLAG_NONE, NULL);
453 mutex_unlock(&bdev->bd_mutex);
454 return PTR_ERR_OR_ZERO(part);
457 int bdev_del_partition(struct block_device *bdev, int partno)
459 struct block_device *part;
462 part = bdget_disk(bdev->bd_disk, partno);
466 mutex_lock(&part->bd_mutex);
467 mutex_lock_nested(&bdev->bd_mutex, 1);
470 if (part->bd_openers)
474 invalidate_bdev(part);
476 delete_partition(part);
479 mutex_unlock(&bdev->bd_mutex);
480 mutex_unlock(&part->bd_mutex);
485 int bdev_resize_partition(struct block_device *bdev, int partno,
486 sector_t start, sector_t length)
488 struct block_device *part;
491 part = bdget_disk(bdev->bd_disk, partno);
495 mutex_lock(&part->bd_mutex);
496 mutex_lock_nested(&bdev->bd_mutex, 1);
498 if (start != part->bd_start_sect)
502 if (partition_overlaps(bdev->bd_disk, start, length, partno))
505 bdev_set_nr_sectors(part, length);
509 mutex_unlock(&part->bd_mutex);
510 mutex_unlock(&bdev->bd_mutex);
515 static bool disk_unlock_native_capacity(struct gendisk *disk)
517 const struct block_device_operations *bdops = disk->fops;
519 if (bdops->unlock_native_capacity &&
520 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
521 printk(KERN_CONT "enabling native capacity\n");
522 bdops->unlock_native_capacity(disk);
523 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
526 printk(KERN_CONT "truncated\n");
531 int blk_drop_partitions(struct block_device *bdev)
533 struct disk_part_iter piter;
534 struct block_device *part;
536 if (bdev->bd_part_count)
540 invalidate_bdev(bdev);
542 disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY);
543 while ((part = disk_part_iter_next(&piter)))
544 delete_partition(part);
545 disk_part_iter_exit(&piter);
550 /* for historic reasons in the DASD driver */
551 EXPORT_SYMBOL_GPL(blk_drop_partitions);
554 static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
555 struct parsed_partitions *state, int p)
557 sector_t size = state->parts[p].size;
558 sector_t from = state->parts[p].from;
559 struct block_device *part;
564 if (from >= get_capacity(disk)) {
566 "%s: p%d start %llu is beyond EOD, ",
567 disk->disk_name, p, (unsigned long long) from);
568 if (disk_unlock_native_capacity(disk))
573 if (from + size > get_capacity(disk)) {
575 "%s: p%d size %llu extends beyond EOD, ",
576 disk->disk_name, p, (unsigned long long) size);
578 if (disk_unlock_native_capacity(disk))
582 * We can not ignore partitions of broken tables created by for
583 * example camera firmware, but we limit them to the end of the
584 * disk to avoid creating invalid block devices.
586 size = get_capacity(disk) - from;
589 part = add_partition(disk, p, from, size, state->parts[p].flags,
590 &state->parts[p].info);
591 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
592 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
593 disk->disk_name, p, -PTR_ERR(part));
597 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
598 (state->parts[p].flags & ADDPART_FLAG_RAID))
599 md_autodetect_dev(part->bd_dev);
604 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
606 struct parsed_partitions *state;
607 int ret = -EAGAIN, p;
609 if (!disk_part_scan_enabled(disk))
612 state = check_partition(disk, bdev);
617 * I/O error reading the partition table. If we tried to read
618 * beyond EOD, retry after unlocking the native capacity.
620 if (PTR_ERR(state) == -ENOSPC) {
621 printk(KERN_WARNING "%s: partition table beyond EOD, ",
623 if (disk_unlock_native_capacity(disk))
630 * Partitions are not supported on host managed zoned block devices.
632 if (disk->queue->limits.zoned == BLK_ZONED_HM) {
633 pr_warn("%s: ignoring partition table on host managed zoned block device\n",
640 * If we read beyond EOD, try unlocking native capacity even if the
641 * partition table was successfully read as we could be missing some
644 if (state->access_beyond_eod) {
646 "%s: partition table partially beyond EOD, ",
648 if (disk_unlock_native_capacity(disk))
652 /* tell userspace that the media / partition table may have changed */
653 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
655 for (p = 1; p < state->limit; p++)
656 if (!blk_add_partition(disk, bdev, state, p))
661 free_partitions(state);
665 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
667 struct address_space *mapping = state->bdev->bd_inode->i_mapping;
670 if (n >= get_capacity(state->bdev->bd_disk)) {
671 state->access_beyond_eod = true;
675 page = read_mapping_page(mapping,
676 (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL);
683 return (unsigned char *)page_address(page) +
684 ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT);