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)
91 spin_lock(&bdev->bd_size_lock);
92 i_size_write(bdev->bd_inode, (loff_t)sectors << SECTOR_SHIFT);
93 spin_unlock(&bdev->bd_size_lock);
96 static struct parsed_partitions *allocate_partitions(struct gendisk *hd)
98 struct parsed_partitions *state;
101 state = kzalloc(sizeof(*state), GFP_KERNEL);
105 nr = disk_max_parts(hd);
106 state->parts = vzalloc(array_size(nr, sizeof(state->parts[0])));
117 static void free_partitions(struct parsed_partitions *state)
123 static struct parsed_partitions *check_partition(struct gendisk *hd,
124 struct block_device *bdev)
126 struct parsed_partitions *state;
129 state = allocate_partitions(hd);
132 state->pp_buf = (char *)__get_free_page(GFP_KERNEL);
133 if (!state->pp_buf) {
134 free_partitions(state);
137 state->pp_buf[0] = '\0';
140 disk_name(hd, 0, state->name);
141 snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name);
142 if (isdigit(state->name[strlen(state->name)-1]))
143 sprintf(state->name, "p");
146 while (!res && check_part[i]) {
147 memset(state->parts, 0, state->limit * sizeof(state->parts[0]));
148 res = check_part[i++](state);
151 * We have hit an I/O error which we don't report now.
152 * But record it, and let the others do their job.
160 printk(KERN_INFO "%s", state->pp_buf);
162 free_page((unsigned long)state->pp_buf);
165 if (state->access_beyond_eod)
168 * The partition is unrecognized. So report I/O errors if there were any
173 strlcat(state->pp_buf,
174 " unable to read partition table\n", PAGE_SIZE);
175 printk(KERN_INFO "%s", state->pp_buf);
178 free_page((unsigned long)state->pp_buf);
179 free_partitions(state);
183 static ssize_t part_partition_show(struct device *dev,
184 struct device_attribute *attr, char *buf)
186 return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_partno);
189 static ssize_t part_start_show(struct device *dev,
190 struct device_attribute *attr, char *buf)
192 return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect);
195 static ssize_t part_ro_show(struct device *dev,
196 struct device_attribute *attr, char *buf)
198 return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev)));
201 static ssize_t part_alignment_offset_show(struct device *dev,
202 struct device_attribute *attr, char *buf)
204 struct block_device *bdev = dev_to_bdev(dev);
206 return sprintf(buf, "%u\n",
207 queue_limit_alignment_offset(&bdev->bd_disk->queue->limits,
208 bdev->bd_start_sect));
211 static ssize_t part_discard_alignment_show(struct device *dev,
212 struct device_attribute *attr, char *buf)
214 struct block_device *bdev = dev_to_bdev(dev);
216 return sprintf(buf, "%u\n",
217 queue_limit_discard_alignment(&bdev->bd_disk->queue->limits,
218 bdev->bd_start_sect));
221 static DEVICE_ATTR(partition, 0444, part_partition_show, NULL);
222 static DEVICE_ATTR(start, 0444, part_start_show, NULL);
223 static DEVICE_ATTR(size, 0444, part_size_show, NULL);
224 static DEVICE_ATTR(ro, 0444, part_ro_show, NULL);
225 static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL);
226 static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL);
227 static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
228 static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
229 #ifdef CONFIG_FAIL_MAKE_REQUEST
230 static struct device_attribute dev_attr_fail =
231 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
234 static struct attribute *part_attrs[] = {
235 &dev_attr_partition.attr,
236 &dev_attr_start.attr,
239 &dev_attr_alignment_offset.attr,
240 &dev_attr_discard_alignment.attr,
242 &dev_attr_inflight.attr,
243 #ifdef CONFIG_FAIL_MAKE_REQUEST
249 static struct attribute_group part_attr_group = {
253 static const struct attribute_group *part_attr_groups[] = {
255 #ifdef CONFIG_BLK_DEV_IO_TRACE
256 &blk_trace_attr_group,
261 static void part_release(struct device *dev)
263 blk_free_devt(dev->devt);
264 bdput(dev_to_bdev(dev));
267 static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
269 struct block_device *part = dev_to_bdev(dev);
271 add_uevent_var(env, "PARTN=%u", part->bd_partno);
272 if (part->bd_meta_info && part->bd_meta_info->volname[0])
273 add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname);
277 struct device_type part_type = {
279 .groups = part_attr_groups,
280 .release = part_release,
281 .uevent = part_uevent,
285 * Must be called either with bd_mutex held, before a disk can be opened or
286 * after all disk users are gone.
288 void delete_partition(struct block_device *part)
290 xa_erase(&part->bd_disk->part_tbl, part->bd_partno);
291 kobject_put(part->bd_holder_dir);
292 device_del(&part->bd_device);
295 * Remove the block device from the inode hash, so that it cannot be
296 * looked up any more even when openers still hold references.
298 remove_inode_hash(part->bd_inode);
300 put_device(&part->bd_device);
303 static ssize_t whole_disk_show(struct device *dev,
304 struct device_attribute *attr, char *buf)
308 static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL);
311 * Must be called either with bd_mutex held, before a disk can be opened or
312 * after all disk users are gone.
314 static struct block_device *add_partition(struct gendisk *disk, int partno,
315 sector_t start, sector_t len, int flags,
316 struct partition_meta_info *info)
318 dev_t devt = MKDEV(0, 0);
319 struct device *ddev = disk_to_dev(disk);
321 struct block_device *bdev;
326 * disk_max_parts() won't be zero, either GENHD_FL_EXT_DEVT is set
327 * or 'minors' is passed to alloc_disk().
329 if (partno >= disk_max_parts(disk))
330 return ERR_PTR(-EINVAL);
333 * Partitions are not supported on zoned block devices that are used as
336 switch (disk->queue->limits.zoned) {
338 pr_warn("%s: partitions not supported on host managed zoned block device\n",
340 return ERR_PTR(-ENXIO);
342 pr_info("%s: disabling host aware zoned block device support due to partitions\n",
344 blk_queue_set_zoned(disk, BLK_ZONED_NONE);
350 if (xa_load(&disk->part_tbl, partno))
351 return ERR_PTR(-EBUSY);
353 bdev = bdev_alloc(disk, partno);
355 return ERR_PTR(-ENOMEM);
357 bdev->bd_start_sect = start;
358 bdev_set_nr_sectors(bdev, len);
362 bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL);
363 if (!bdev->bd_meta_info)
367 pdev = &bdev->bd_device;
368 dname = dev_name(ddev);
369 if (isdigit(dname[strlen(dname) - 1]))
370 dev_set_name(pdev, "%sp%d", dname, partno);
372 dev_set_name(pdev, "%s%d", dname, partno);
374 device_initialize(pdev);
375 pdev->class = &block_class;
376 pdev->type = &part_type;
379 err = blk_alloc_devt(bdev, &devt);
384 /* delay uevent until 'holders' subdir is created */
385 dev_set_uevent_suppress(pdev, 1);
386 err = device_add(pdev);
391 bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj);
392 if (!bdev->bd_holder_dir)
395 dev_set_uevent_suppress(pdev, 0);
396 if (flags & ADDPART_FLAG_WHOLEDISK) {
397 err = device_create_file(pdev, &dev_attr_whole_disk);
402 /* everything is up and running, commence */
403 err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL);
406 bdev_add(bdev, devt);
408 /* suppress uevent if the disk suppresses it */
409 if (!dev_get_uevent_suppress(ddev))
410 kobject_uevent(&pdev->kobj, KOBJ_ADD);
417 kobject_put(bdev->bd_holder_dir);
424 static bool partition_overlaps(struct gendisk *disk, sector_t start,
425 sector_t length, int skip_partno)
427 struct disk_part_iter piter;
428 struct block_device *part;
429 bool overlap = false;
431 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
432 while ((part = disk_part_iter_next(&piter))) {
433 if (part->bd_partno == skip_partno ||
434 start >= part->bd_start_sect + bdev_nr_sectors(part) ||
435 start + length <= part->bd_start_sect)
441 disk_part_iter_exit(&piter);
445 int bdev_add_partition(struct block_device *bdev, int partno,
446 sector_t start, sector_t length)
448 struct block_device *part;
450 mutex_lock(&bdev->bd_mutex);
451 if (partition_overlaps(bdev->bd_disk, start, length, -1)) {
452 mutex_unlock(&bdev->bd_mutex);
456 part = add_partition(bdev->bd_disk, partno, start, length,
457 ADDPART_FLAG_NONE, NULL);
458 mutex_unlock(&bdev->bd_mutex);
459 return PTR_ERR_OR_ZERO(part);
462 int bdev_del_partition(struct block_device *bdev, int partno)
464 struct block_device *part;
467 part = bdget_disk(bdev->bd_disk, partno);
471 mutex_lock(&part->bd_mutex);
472 mutex_lock_nested(&bdev->bd_mutex, 1);
475 if (part->bd_openers)
479 invalidate_bdev(part);
481 delete_partition(part);
484 mutex_unlock(&bdev->bd_mutex);
485 mutex_unlock(&part->bd_mutex);
490 int bdev_resize_partition(struct block_device *bdev, int partno,
491 sector_t start, sector_t length)
493 struct block_device *part;
496 part = bdget_disk(bdev->bd_disk, partno);
500 mutex_lock(&part->bd_mutex);
501 mutex_lock_nested(&bdev->bd_mutex, 1);
503 if (start != part->bd_start_sect)
507 if (partition_overlaps(bdev->bd_disk, start, length, partno))
510 bdev_set_nr_sectors(part, length);
514 mutex_unlock(&part->bd_mutex);
515 mutex_unlock(&bdev->bd_mutex);
520 static bool disk_unlock_native_capacity(struct gendisk *disk)
522 const struct block_device_operations *bdops = disk->fops;
524 if (bdops->unlock_native_capacity &&
525 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
526 printk(KERN_CONT "enabling native capacity\n");
527 bdops->unlock_native_capacity(disk);
528 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
531 printk(KERN_CONT "truncated\n");
536 int blk_drop_partitions(struct block_device *bdev)
538 struct disk_part_iter piter;
539 struct block_device *part;
541 if (bdev->bd_part_count)
545 invalidate_bdev(bdev);
547 disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY);
548 while ((part = disk_part_iter_next(&piter)))
549 delete_partition(part);
550 disk_part_iter_exit(&piter);
555 /* for historic reasons in the DASD driver */
556 EXPORT_SYMBOL_GPL(blk_drop_partitions);
559 static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev,
560 struct parsed_partitions *state, int p)
562 sector_t size = state->parts[p].size;
563 sector_t from = state->parts[p].from;
564 struct block_device *part;
569 if (from >= get_capacity(disk)) {
571 "%s: p%d start %llu is beyond EOD, ",
572 disk->disk_name, p, (unsigned long long) from);
573 if (disk_unlock_native_capacity(disk))
578 if (from + size > get_capacity(disk)) {
580 "%s: p%d size %llu extends beyond EOD, ",
581 disk->disk_name, p, (unsigned long long) size);
583 if (disk_unlock_native_capacity(disk))
587 * We can not ignore partitions of broken tables created by for
588 * example camera firmware, but we limit them to the end of the
589 * disk to avoid creating invalid block devices.
591 size = get_capacity(disk) - from;
594 part = add_partition(disk, p, from, size, state->parts[p].flags,
595 &state->parts[p].info);
596 if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) {
597 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
598 disk->disk_name, p, -PTR_ERR(part));
602 if (IS_BUILTIN(CONFIG_BLK_DEV_MD) &&
603 (state->parts[p].flags & ADDPART_FLAG_RAID))
604 md_autodetect_dev(part->bd_dev);
609 int blk_add_partitions(struct gendisk *disk, struct block_device *bdev)
611 struct parsed_partitions *state;
612 int ret = -EAGAIN, p;
614 if (!disk_part_scan_enabled(disk))
617 state = check_partition(disk, bdev);
622 * I/O error reading the partition table. If we tried to read
623 * beyond EOD, retry after unlocking the native capacity.
625 if (PTR_ERR(state) == -ENOSPC) {
626 printk(KERN_WARNING "%s: partition table beyond EOD, ",
628 if (disk_unlock_native_capacity(disk))
635 * Partitions are not supported on host managed zoned block devices.
637 if (disk->queue->limits.zoned == BLK_ZONED_HM) {
638 pr_warn("%s: ignoring partition table on host managed zoned block device\n",
645 * If we read beyond EOD, try unlocking native capacity even if the
646 * partition table was successfully read as we could be missing some
649 if (state->access_beyond_eod) {
651 "%s: partition table partially beyond EOD, ",
653 if (disk_unlock_native_capacity(disk))
657 /* tell userspace that the media / partition table may have changed */
658 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
660 for (p = 1; p < state->limit; p++)
661 if (!blk_add_partition(disk, bdev, state, p))
666 free_partitions(state);
670 void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p)
672 struct address_space *mapping = state->bdev->bd_inode->i_mapping;
675 if (n >= get_capacity(state->bdev->bd_disk)) {
676 state->access_beyond_eod = true;
680 page = read_mapping_page(mapping,
681 (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL);
688 return (unsigned char *)page_address(page) +
689 ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT);