| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 1991-1998 Linus Torvalds |
| * Re-organised Feb 1998 Russell King |
| * Copyright (C) 2020 Christoph Hellwig |
| */ |
| #include <linux/fs.h> |
| #include <linux/major.h> |
| #include <linux/slab.h> |
| #include <linux/ctype.h> |
| #include <linux/vmalloc.h> |
| #include <linux/raid/detect.h> |
| #include "check.h" |
| |
| static int (*const check_part[])(struct parsed_partitions *) = { |
| /* |
| * Probe partition formats with tables at disk address 0 |
| * that also have an ADFS boot block at 0xdc0. |
| */ |
| #ifdef CONFIG_ACORN_PARTITION_ICS |
| adfspart_check_ICS, |
| #endif |
| #ifdef CONFIG_ACORN_PARTITION_POWERTEC |
| adfspart_check_POWERTEC, |
| #endif |
| #ifdef CONFIG_ACORN_PARTITION_EESOX |
| adfspart_check_EESOX, |
| #endif |
| |
| /* |
| * Now move on to formats that only have partition info at |
| * disk address 0xdc0. Since these may also have stale |
| * PC/BIOS partition tables, they need to come before |
| * the msdos entry. |
| */ |
| #ifdef CONFIG_ACORN_PARTITION_CUMANA |
| adfspart_check_CUMANA, |
| #endif |
| #ifdef CONFIG_ACORN_PARTITION_ADFS |
| adfspart_check_ADFS, |
| #endif |
| |
| #ifdef CONFIG_CMDLINE_PARTITION |
| cmdline_partition, |
| #endif |
| #ifdef CONFIG_EFI_PARTITION |
| efi_partition, /* this must come before msdos */ |
| #endif |
| #ifdef CONFIG_SGI_PARTITION |
| sgi_partition, |
| #endif |
| #ifdef CONFIG_LDM_PARTITION |
| ldm_partition, /* this must come before msdos */ |
| #endif |
| #ifdef CONFIG_MSDOS_PARTITION |
| msdos_partition, |
| #endif |
| #ifdef CONFIG_OSF_PARTITION |
| osf_partition, |
| #endif |
| #ifdef CONFIG_SUN_PARTITION |
| sun_partition, |
| #endif |
| #ifdef CONFIG_AMIGA_PARTITION |
| amiga_partition, |
| #endif |
| #ifdef CONFIG_ATARI_PARTITION |
| atari_partition, |
| #endif |
| #ifdef CONFIG_MAC_PARTITION |
| mac_partition, |
| #endif |
| #ifdef CONFIG_ULTRIX_PARTITION |
| ultrix_partition, |
| #endif |
| #ifdef CONFIG_IBM_PARTITION |
| ibm_partition, |
| #endif |
| #ifdef CONFIG_KARMA_PARTITION |
| karma_partition, |
| #endif |
| #ifdef CONFIG_SYSV68_PARTITION |
| sysv68_partition, |
| #endif |
| NULL |
| }; |
| |
| static struct parsed_partitions *allocate_partitions(struct gendisk *hd) |
| { |
| struct parsed_partitions *state; |
| int nr = DISK_MAX_PARTS; |
| |
| state = kzalloc(sizeof(*state), GFP_KERNEL); |
| if (!state) |
| return NULL; |
| |
| state->parts = vzalloc(array_size(nr, sizeof(state->parts[0]))); |
| if (!state->parts) { |
| kfree(state); |
| return NULL; |
| } |
| |
| state->limit = nr; |
| |
| return state; |
| } |
| |
| static void free_partitions(struct parsed_partitions *state) |
| { |
| vfree(state->parts); |
| kfree(state); |
| } |
| |
| static struct parsed_partitions *check_partition(struct gendisk *hd) |
| { |
| struct parsed_partitions *state; |
| int i, res, err; |
| |
| state = allocate_partitions(hd); |
| if (!state) |
| return NULL; |
| state->pp_buf = (char *)__get_free_page(GFP_KERNEL); |
| if (!state->pp_buf) { |
| free_partitions(state); |
| return NULL; |
| } |
| state->pp_buf[0] = '\0'; |
| |
| state->disk = hd; |
| snprintf(state->name, BDEVNAME_SIZE, "%s", hd->disk_name); |
| snprintf(state->pp_buf, PAGE_SIZE, " %s:", state->name); |
| if (isdigit(state->name[strlen(state->name)-1])) |
| sprintf(state->name, "p"); |
| |
| i = res = err = 0; |
| while (!res && check_part[i]) { |
| memset(state->parts, 0, state->limit * sizeof(state->parts[0])); |
| res = check_part[i++](state); |
| if (res < 0) { |
| /* |
| * We have hit an I/O error which we don't report now. |
| * But record it, and let the others do their job. |
| */ |
| err = res; |
| res = 0; |
| } |
| |
| } |
| if (res > 0) { |
| printk(KERN_INFO "%s", state->pp_buf); |
| |
| free_page((unsigned long)state->pp_buf); |
| return state; |
| } |
| if (state->access_beyond_eod) |
| err = -ENOSPC; |
| /* |
| * The partition is unrecognized. So report I/O errors if there were any |
| */ |
| if (err) |
| res = err; |
| if (res) { |
| strlcat(state->pp_buf, |
| " unable to read partition table\n", PAGE_SIZE); |
| printk(KERN_INFO "%s", state->pp_buf); |
| } |
| |
| free_page((unsigned long)state->pp_buf); |
| free_partitions(state); |
| return ERR_PTR(res); |
| } |
| |
| static ssize_t part_partition_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", bdev_partno(dev_to_bdev(dev))); |
| } |
| |
| static ssize_t part_start_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%llu\n", dev_to_bdev(dev)->bd_start_sect); |
| } |
| |
| static ssize_t part_ro_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev))); |
| } |
| |
| static ssize_t part_alignment_offset_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%u\n", bdev_alignment_offset(dev_to_bdev(dev))); |
| } |
| |
| static ssize_t part_discard_alignment_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%u\n", bdev_discard_alignment(dev_to_bdev(dev))); |
| } |
| |
| static DEVICE_ATTR(partition, 0444, part_partition_show, NULL); |
| static DEVICE_ATTR(start, 0444, part_start_show, NULL); |
| static DEVICE_ATTR(size, 0444, part_size_show, NULL); |
| static DEVICE_ATTR(ro, 0444, part_ro_show, NULL); |
| static DEVICE_ATTR(alignment_offset, 0444, part_alignment_offset_show, NULL); |
| static DEVICE_ATTR(discard_alignment, 0444, part_discard_alignment_show, NULL); |
| static DEVICE_ATTR(stat, 0444, part_stat_show, NULL); |
| static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL); |
| #ifdef CONFIG_FAIL_MAKE_REQUEST |
| static struct device_attribute dev_attr_fail = |
| __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store); |
| #endif |
| |
| static struct attribute *part_attrs[] = { |
| &dev_attr_partition.attr, |
| &dev_attr_start.attr, |
| &dev_attr_size.attr, |
| &dev_attr_ro.attr, |
| &dev_attr_alignment_offset.attr, |
| &dev_attr_discard_alignment.attr, |
| &dev_attr_stat.attr, |
| &dev_attr_inflight.attr, |
| #ifdef CONFIG_FAIL_MAKE_REQUEST |
| &dev_attr_fail.attr, |
| #endif |
| NULL |
| }; |
| |
| static const struct attribute_group part_attr_group = { |
| .attrs = part_attrs, |
| }; |
| |
| static const struct attribute_group *part_attr_groups[] = { |
| &part_attr_group, |
| #ifdef CONFIG_BLK_DEV_IO_TRACE |
| &blk_trace_attr_group, |
| #endif |
| NULL |
| }; |
| |
| static void part_release(struct device *dev) |
| { |
| put_disk(dev_to_bdev(dev)->bd_disk); |
| bdev_drop(dev_to_bdev(dev)); |
| } |
| |
| static int part_uevent(const struct device *dev, struct kobj_uevent_env *env) |
| { |
| const struct block_device *part = dev_to_bdev(dev); |
| |
| add_uevent_var(env, "PARTN=%u", bdev_partno(part)); |
| if (part->bd_meta_info && part->bd_meta_info->volname[0]) |
| add_uevent_var(env, "PARTNAME=%s", part->bd_meta_info->volname); |
| return 0; |
| } |
| |
| const struct device_type part_type = { |
| .name = "partition", |
| .groups = part_attr_groups, |
| .release = part_release, |
| .uevent = part_uevent, |
| }; |
| |
| void drop_partition(struct block_device *part) |
| { |
| lockdep_assert_held(&part->bd_disk->open_mutex); |
| |
| xa_erase(&part->bd_disk->part_tbl, bdev_partno(part)); |
| kobject_put(part->bd_holder_dir); |
| |
| device_del(&part->bd_device); |
| put_device(&part->bd_device); |
| } |
| |
| static ssize_t whole_disk_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return 0; |
| } |
| static const DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); |
| |
| /* |
| * Must be called either with open_mutex held, before a disk can be opened or |
| * after all disk users are gone. |
| */ |
| static struct block_device *add_partition(struct gendisk *disk, int partno, |
| sector_t start, sector_t len, int flags, |
| struct partition_meta_info *info) |
| { |
| dev_t devt = MKDEV(0, 0); |
| struct device *ddev = disk_to_dev(disk); |
| struct device *pdev; |
| struct block_device *bdev; |
| const char *dname; |
| int err; |
| |
| lockdep_assert_held(&disk->open_mutex); |
| |
| if (partno >= DISK_MAX_PARTS) |
| return ERR_PTR(-EINVAL); |
| |
| /* |
| * Partitions are not supported on zoned block devices that are used as |
| * such. |
| */ |
| if (bdev_is_zoned(disk->part0)) { |
| pr_warn("%s: partitions not supported on host managed zoned block device\n", |
| disk->disk_name); |
| return ERR_PTR(-ENXIO); |
| } |
| |
| if (xa_load(&disk->part_tbl, partno)) |
| return ERR_PTR(-EBUSY); |
| |
| /* ensure we always have a reference to the whole disk */ |
| get_device(disk_to_dev(disk)); |
| |
| err = -ENOMEM; |
| bdev = bdev_alloc(disk, partno); |
| if (!bdev) |
| goto out_put_disk; |
| |
| bdev->bd_start_sect = start; |
| bdev_set_nr_sectors(bdev, len); |
| |
| pdev = &bdev->bd_device; |
| dname = dev_name(ddev); |
| if (isdigit(dname[strlen(dname) - 1])) |
| dev_set_name(pdev, "%sp%d", dname, partno); |
| else |
| dev_set_name(pdev, "%s%d", dname, partno); |
| |
| device_initialize(pdev); |
| pdev->class = &block_class; |
| pdev->type = &part_type; |
| pdev->parent = ddev; |
| |
| /* in consecutive minor range? */ |
| if (bdev_partno(bdev) < disk->minors) { |
| devt = MKDEV(disk->major, disk->first_minor + bdev_partno(bdev)); |
| } else { |
| err = blk_alloc_ext_minor(); |
| if (err < 0) |
| goto out_put; |
| devt = MKDEV(BLOCK_EXT_MAJOR, err); |
| } |
| pdev->devt = devt; |
| |
| if (info) { |
| err = -ENOMEM; |
| bdev->bd_meta_info = kmemdup(info, sizeof(*info), GFP_KERNEL); |
| if (!bdev->bd_meta_info) |
| goto out_put; |
| } |
| |
| /* delay uevent until 'holders' subdir is created */ |
| dev_set_uevent_suppress(pdev, 1); |
| err = device_add(pdev); |
| if (err) |
| goto out_put; |
| |
| err = -ENOMEM; |
| bdev->bd_holder_dir = kobject_create_and_add("holders", &pdev->kobj); |
| if (!bdev->bd_holder_dir) |
| goto out_del; |
| |
| dev_set_uevent_suppress(pdev, 0); |
| if (flags & ADDPART_FLAG_WHOLEDISK) { |
| err = device_create_file(pdev, &dev_attr_whole_disk); |
| if (err) |
| goto out_del; |
| } |
| |
| /* everything is up and running, commence */ |
| err = xa_insert(&disk->part_tbl, partno, bdev, GFP_KERNEL); |
| if (err) |
| goto out_del; |
| bdev_add(bdev, devt); |
| |
| /* suppress uevent if the disk suppresses it */ |
| if (!dev_get_uevent_suppress(ddev)) |
| kobject_uevent(&pdev->kobj, KOBJ_ADD); |
| return bdev; |
| |
| out_del: |
| kobject_put(bdev->bd_holder_dir); |
| device_del(pdev); |
| out_put: |
| put_device(pdev); |
| return ERR_PTR(err); |
| out_put_disk: |
| put_disk(disk); |
| return ERR_PTR(err); |
| } |
| |
| static bool partition_overlaps(struct gendisk *disk, sector_t start, |
| sector_t length, int skip_partno) |
| { |
| struct block_device *part; |
| bool overlap = false; |
| unsigned long idx; |
| |
| rcu_read_lock(); |
| xa_for_each_start(&disk->part_tbl, idx, part, 1) { |
| if (bdev_partno(part) != skip_partno && |
| start < part->bd_start_sect + bdev_nr_sectors(part) && |
| start + length > part->bd_start_sect) { |
| overlap = true; |
| break; |
| } |
| } |
| rcu_read_unlock(); |
| |
| return overlap; |
| } |
| |
| int bdev_add_partition(struct gendisk *disk, int partno, sector_t start, |
| sector_t length) |
| { |
| struct block_device *part; |
| int ret; |
| |
| mutex_lock(&disk->open_mutex); |
| if (!disk_live(disk)) { |
| ret = -ENXIO; |
| goto out; |
| } |
| |
| if (disk->flags & GENHD_FL_NO_PART) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| if (partition_overlaps(disk, start, length, -1)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| |
| part = add_partition(disk, partno, start, length, |
| ADDPART_FLAG_NONE, NULL); |
| ret = PTR_ERR_OR_ZERO(part); |
| out: |
| mutex_unlock(&disk->open_mutex); |
| return ret; |
| } |
| |
| int bdev_del_partition(struct gendisk *disk, int partno) |
| { |
| struct block_device *part = NULL; |
| int ret = -ENXIO; |
| |
| mutex_lock(&disk->open_mutex); |
| part = xa_load(&disk->part_tbl, partno); |
| if (!part) |
| goto out_unlock; |
| |
| ret = -EBUSY; |
| if (atomic_read(&part->bd_openers)) |
| goto out_unlock; |
| |
| /* |
| * We verified that @part->bd_openers is zero above and so |
| * @part->bd_holder{_ops} can't be set. And since we hold |
| * @disk->open_mutex the device can't be claimed by anyone. |
| * |
| * So no need to call @part->bd_holder_ops->mark_dead() here. |
| * Just delete the partition and invalidate it. |
| */ |
| |
| bdev_unhash(part); |
| invalidate_bdev(part); |
| drop_partition(part); |
| ret = 0; |
| out_unlock: |
| mutex_unlock(&disk->open_mutex); |
| return ret; |
| } |
| |
| int bdev_resize_partition(struct gendisk *disk, int partno, sector_t start, |
| sector_t length) |
| { |
| struct block_device *part = NULL; |
| int ret = -ENXIO; |
| |
| mutex_lock(&disk->open_mutex); |
| part = xa_load(&disk->part_tbl, partno); |
| if (!part) |
| goto out_unlock; |
| |
| ret = -EINVAL; |
| if (start != part->bd_start_sect) |
| goto out_unlock; |
| |
| ret = -EBUSY; |
| if (partition_overlaps(disk, start, length, partno)) |
| goto out_unlock; |
| |
| bdev_set_nr_sectors(part, length); |
| |
| ret = 0; |
| out_unlock: |
| mutex_unlock(&disk->open_mutex); |
| return ret; |
| } |
| |
| static bool disk_unlock_native_capacity(struct gendisk *disk) |
| { |
| if (!disk->fops->unlock_native_capacity || |
| test_and_set_bit(GD_NATIVE_CAPACITY, &disk->state)) { |
| printk(KERN_CONT "truncated\n"); |
| return false; |
| } |
| |
| printk(KERN_CONT "enabling native capacity\n"); |
| disk->fops->unlock_native_capacity(disk); |
| return true; |
| } |
| |
| static bool blk_add_partition(struct gendisk *disk, |
| struct parsed_partitions *state, int p) |
| { |
| sector_t size = state->parts[p].size; |
| sector_t from = state->parts[p].from; |
| struct block_device *part; |
| |
| if (!size) |
| return true; |
| |
| if (from >= get_capacity(disk)) { |
| printk(KERN_WARNING |
| "%s: p%d start %llu is beyond EOD, ", |
| disk->disk_name, p, (unsigned long long) from); |
| if (disk_unlock_native_capacity(disk)) |
| return false; |
| return true; |
| } |
| |
| if (from + size > get_capacity(disk)) { |
| printk(KERN_WARNING |
| "%s: p%d size %llu extends beyond EOD, ", |
| disk->disk_name, p, (unsigned long long) size); |
| |
| if (disk_unlock_native_capacity(disk)) |
| return false; |
| |
| /* |
| * We can not ignore partitions of broken tables created by for |
| * example camera firmware, but we limit them to the end of the |
| * disk to avoid creating invalid block devices. |
| */ |
| size = get_capacity(disk) - from; |
| } |
| |
| part = add_partition(disk, p, from, size, state->parts[p].flags, |
| &state->parts[p].info); |
| if (IS_ERR(part) && PTR_ERR(part) != -ENXIO) { |
| printk(KERN_ERR " %s: p%d could not be added: %pe\n", |
| disk->disk_name, p, part); |
| return true; |
| } |
| |
| if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && |
| (state->parts[p].flags & ADDPART_FLAG_RAID)) |
| md_autodetect_dev(part->bd_dev); |
| |
| return true; |
| } |
| |
| static int blk_add_partitions(struct gendisk *disk) |
| { |
| struct parsed_partitions *state; |
| int ret = -EAGAIN, p; |
| |
| if (!disk_has_partscan(disk)) |
| return 0; |
| |
| state = check_partition(disk); |
| if (!state) |
| return 0; |
| if (IS_ERR(state)) { |
| /* |
| * I/O error reading the partition table. If we tried to read |
| * beyond EOD, retry after unlocking the native capacity. |
| */ |
| if (PTR_ERR(state) == -ENOSPC) { |
| printk(KERN_WARNING "%s: partition table beyond EOD, ", |
| disk->disk_name); |
| if (disk_unlock_native_capacity(disk)) |
| return -EAGAIN; |
| } |
| return -EIO; |
| } |
| |
| /* |
| * Partitions are not supported on host managed zoned block devices. |
| */ |
| if (bdev_is_zoned(disk->part0)) { |
| pr_warn("%s: ignoring partition table on host managed zoned block device\n", |
| disk->disk_name); |
| ret = 0; |
| goto out_free_state; |
| } |
| |
| /* |
| * If we read beyond EOD, try unlocking native capacity even if the |
| * partition table was successfully read as we could be missing some |
| * partitions. |
| */ |
| if (state->access_beyond_eod) { |
| printk(KERN_WARNING |
| "%s: partition table partially beyond EOD, ", |
| disk->disk_name); |
| if (disk_unlock_native_capacity(disk)) |
| goto out_free_state; |
| } |
| |
| /* tell userspace that the media / partition table may have changed */ |
| kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); |
| |
| for (p = 1; p < state->limit; p++) |
| if (!blk_add_partition(disk, state, p)) |
| goto out_free_state; |
| |
| ret = 0; |
| out_free_state: |
| free_partitions(state); |
| return ret; |
| } |
| |
| int bdev_disk_changed(struct gendisk *disk, bool invalidate) |
| { |
| struct block_device *part; |
| unsigned long idx; |
| int ret = 0; |
| |
| lockdep_assert_held(&disk->open_mutex); |
| |
| if (!disk_live(disk)) |
| return -ENXIO; |
| |
| rescan: |
| if (disk->open_partitions) |
| return -EBUSY; |
| sync_blockdev(disk->part0); |
| invalidate_bdev(disk->part0); |
| |
| xa_for_each_start(&disk->part_tbl, idx, part, 1) { |
| /* |
| * Remove the block device from the inode hash, so that |
| * it cannot be looked up any more even when openers |
| * still hold references. |
| */ |
| bdev_unhash(part); |
| |
| /* |
| * If @disk->open_partitions isn't elevated but there's |
| * still an active holder of that block device things |
| * are broken. |
| */ |
| WARN_ON_ONCE(atomic_read(&part->bd_openers)); |
| invalidate_bdev(part); |
| drop_partition(part); |
| } |
| clear_bit(GD_NEED_PART_SCAN, &disk->state); |
| |
| /* |
| * Historically we only set the capacity to zero for devices that |
| * support partitions (independ of actually having partitions created). |
| * Doing that is rather inconsistent, but changing it broke legacy |
| * udisks polling for legacy ide-cdrom devices. Use the crude check |
| * below to get the sane behavior for most device while not breaking |
| * userspace for this particular setup. |
| */ |
| if (invalidate) { |
| if (!(disk->flags & GENHD_FL_NO_PART) || |
| !(disk->flags & GENHD_FL_REMOVABLE)) |
| set_capacity(disk, 0); |
| } |
| |
| if (get_capacity(disk)) { |
| ret = blk_add_partitions(disk); |
| if (ret == -EAGAIN) |
| goto rescan; |
| } else if (invalidate) { |
| /* |
| * Tell userspace that the media / partition table may have |
| * changed. |
| */ |
| kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); |
| } |
| |
| return ret; |
| } |
| /* |
| * Only exported for loop and dasd for historic reasons. Don't use in new |
| * code! |
| */ |
| EXPORT_SYMBOL_GPL(bdev_disk_changed); |
| |
| void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) |
| { |
| struct address_space *mapping = state->disk->part0->bd_mapping; |
| struct folio *folio; |
| |
| if (n >= get_capacity(state->disk)) { |
| state->access_beyond_eod = true; |
| goto out; |
| } |
| |
| folio = read_mapping_folio(mapping, n >> PAGE_SECTORS_SHIFT, NULL); |
| if (IS_ERR(folio)) |
| goto out; |
| |
| p->v = folio; |
| return folio_address(folio) + offset_in_folio(folio, n * SECTOR_SIZE); |
| out: |
| p->v = NULL; |
| return NULL; |
| } |