// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 1991-1998 Linus Torvalds * Re-organised Feb 1998 Russell King */ #include #include #include #include #include #include #include #include "check.h" static int (*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; state = kzalloc(sizeof(*state), GFP_KERNEL); if (!state) return NULL; nr = disk_max_parts(hd); 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 block_device *bdev) { 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->bdev = bdev; disk_name(hd, 0, state->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) { struct hd_struct *p = dev_to_part(dev); return sprintf(buf, "%d\n", p->partno); } static ssize_t part_start_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect); } static ssize_t part_ro_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); return sprintf(buf, "%d\n", p->policy ? 1 : 0); } static ssize_t part_alignment_offset_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset); } static ssize_t part_discard_alignment_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); return sprintf(buf, "%u\n", p->discard_alignment); } 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 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) { struct hd_struct *p = dev_to_part(dev); blk_free_devt(dev->devt); hd_free_part(p); kfree(p); } static int part_uevent(struct device *dev, struct kobj_uevent_env *env) { struct hd_struct *part = dev_to_part(dev); add_uevent_var(env, "PARTN=%u", part->partno); if (part->info && part->info->volname[0]) add_uevent_var(env, "PARTNAME=%s", part->info->volname); return 0; } struct device_type part_type = { .name = "partition", .groups = part_attr_groups, .release = part_release, .uevent = part_uevent, }; static void hd_struct_free_work(struct work_struct *work) { struct hd_struct *part = container_of(to_rcu_work(work), struct hd_struct, rcu_work); part->start_sect = 0; part->nr_sects = 0; part_stat_set_all(part, 0); put_device(part_to_dev(part)); } static void hd_struct_free(struct percpu_ref *ref) { struct hd_struct *part = container_of(ref, struct hd_struct, ref); struct gendisk *disk = part_to_disk(part); struct disk_part_tbl *ptbl = rcu_dereference_protected(disk->part_tbl, 1); rcu_assign_pointer(ptbl->last_lookup, NULL); put_device(disk_to_dev(disk)); INIT_RCU_WORK(&part->rcu_work, hd_struct_free_work); queue_rcu_work(system_wq, &part->rcu_work); } int hd_ref_init(struct hd_struct *part) { if (percpu_ref_init(&part->ref, hd_struct_free, 0, GFP_KERNEL)) return -ENOMEM; return 0; } /* * Must be called either with bd_mutex held, before a disk can be opened or * after all disk users are gone. */ void delete_partition(struct gendisk *disk, struct hd_struct *part) { struct disk_part_tbl *ptbl = rcu_dereference_protected(disk->part_tbl, 1); /* * ->part_tbl is referenced in this part's release handler, so * we have to hold the disk device */ get_device(disk_to_dev(part_to_disk(part))); rcu_assign_pointer(ptbl->part[part->partno], NULL); kobject_put(part->holder_dir); device_del(part_to_dev(part)); /* * Remove gendisk pointer from idr so that it cannot be looked up * while RCU period before freeing gendisk is running to prevent * use-after-free issues. Note that the device number stays * "in-use" until we really free the gendisk. */ blk_invalidate_devt(part_devt(part)); percpu_ref_kill(&part->ref); } static ssize_t whole_disk_show(struct device *dev, struct device_attribute *attr, char *buf) { return 0; } static DEVICE_ATTR(whole_disk, 0444, whole_disk_show, NULL); /* * Must be called either with bd_mutex held, before a disk can be opened or * after all disk users are gone. */ static struct hd_struct *add_partition(struct gendisk *disk, int partno, sector_t start, sector_t len, int flags, struct partition_meta_info *info) { struct hd_struct *p; dev_t devt = MKDEV(0, 0); struct device *ddev = disk_to_dev(disk); struct device *pdev; struct disk_part_tbl *ptbl; const char *dname; int err; /* * Partitions are not supported on zoned block devices that are used as * such. */ switch (disk->queue->limits.zoned) { case BLK_ZONED_HM: pr_warn("%s: partitions not supported on host managed zoned block device\n", disk->disk_name); return ERR_PTR(-ENXIO); case BLK_ZONED_HA: pr_info("%s: disabling host aware zoned block device support due to partitions\n", disk->disk_name); disk->queue->limits.zoned = BLK_ZONED_NONE; break; case BLK_ZONED_NONE: break; } err = disk_expand_part_tbl(disk, partno); if (err) return ERR_PTR(err); ptbl = rcu_dereference_protected(disk->part_tbl, 1); if (ptbl->part[partno]) return ERR_PTR(-EBUSY); p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) return ERR_PTR(-EBUSY); p->dkstats = alloc_percpu(struct disk_stats); if (!p->dkstats) { err = -ENOMEM; goto out_free; } hd_sects_seq_init(p); pdev = part_to_dev(p); p->start_sect = start; p->alignment_offset = queue_limit_alignment_offset(&disk->queue->limits, start); p->discard_alignment = queue_limit_discard_alignment(&disk->queue->limits, start); p->nr_sects = len; p->partno = partno; p->policy = get_disk_ro(disk); if (info) { struct partition_meta_info *pinfo; pinfo = kzalloc_node(sizeof(*pinfo), GFP_KERNEL, disk->node_id); if (!pinfo) { err = -ENOMEM; goto out_free_stats; } memcpy(pinfo, info, sizeof(*info)); p->info = pinfo; } 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; err = blk_alloc_devt(p, &devt); if (err) goto out_free_info; pdev->devt = devt; /* delay uevent until 'holders' subdir is created */ dev_set_uevent_suppress(pdev, 1); err = device_add(pdev); if (err) goto out_put; err = -ENOMEM; p->holder_dir = kobject_create_and_add("holders", &pdev->kobj); if (!p->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; } err = hd_ref_init(p); if (err) { if (flags & ADDPART_FLAG_WHOLEDISK) goto out_remove_file; goto out_del; } /* everything is up and running, commence */ rcu_assign_pointer(ptbl->part[partno], p); /* suppress uevent if the disk suppresses it */ if (!dev_get_uevent_suppress(ddev)) kobject_uevent(&pdev->kobj, KOBJ_ADD); return p; out_free_info: kfree(p->info); out_free_stats: free_percpu(p->dkstats); out_free: kfree(p); return ERR_PTR(err); out_remove_file: device_remove_file(pdev, &dev_attr_whole_disk); out_del: kobject_put(p->holder_dir); device_del(pdev); out_put: put_device(pdev); return ERR_PTR(err); } static bool partition_overlaps(struct gendisk *disk, sector_t start, sector_t length, int skip_partno) { struct disk_part_iter piter; struct hd_struct *part; bool overlap = false; disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); while ((part = disk_part_iter_next(&piter))) { if (part->partno == skip_partno || start >= part->start_sect + part->nr_sects || start + length <= part->start_sect) continue; overlap = true; break; } disk_part_iter_exit(&piter); return overlap; } int bdev_add_partition(struct block_device *bdev, int partno, sector_t start, sector_t length) { struct hd_struct *part; mutex_lock(&bdev->bd_mutex); if (partition_overlaps(bdev->bd_disk, start, length, -1)) { mutex_unlock(&bdev->bd_mutex); return -EBUSY; } part = add_partition(bdev->bd_disk, partno, start, length, ADDPART_FLAG_NONE, NULL); mutex_unlock(&bdev->bd_mutex); return PTR_ERR_OR_ZERO(part); } int bdev_del_partition(struct block_device *bdev, int partno) { struct block_device *bdevp; struct hd_struct *part; int ret = 0; part = disk_get_part(bdev->bd_disk, partno); if (!part) return -ENXIO; ret = -ENOMEM; bdevp = bdget(part_devt(part)); if (!bdevp) goto out_put_part; mutex_lock(&bdevp->bd_mutex); ret = -EBUSY; if (bdevp->bd_openers) goto out_unlock; sync_blockdev(bdevp); invalidate_bdev(bdevp); mutex_lock_nested(&bdev->bd_mutex, 1); delete_partition(bdev->bd_disk, part); mutex_unlock(&bdev->bd_mutex); ret = 0; out_unlock: mutex_unlock(&bdevp->bd_mutex); bdput(bdevp); out_put_part: disk_put_part(part); return ret; } int bdev_resize_partition(struct block_device *bdev, int partno, sector_t start, sector_t length) { struct block_device *bdevp; struct hd_struct *part; int ret = 0; part = disk_get_part(bdev->bd_disk, partno); if (!part) return -ENXIO; ret = -ENOMEM; bdevp = bdget(part_devt(part)); if (!bdevp) goto out_put_part; mutex_lock(&bdevp->bd_mutex); mutex_lock_nested(&bdev->bd_mutex, 1); ret = -EINVAL; if (start != part->start_sect) goto out_unlock; ret = -EBUSY; if (partition_overlaps(bdev->bd_disk, start, length, partno)) goto out_unlock; part_nr_sects_write(part, (sector_t)length); i_size_write(bdevp->bd_inode, length << SECTOR_SHIFT); ret = 0; out_unlock: mutex_unlock(&bdevp->bd_mutex); mutex_unlock(&bdev->bd_mutex); bdput(bdevp); out_put_part: disk_put_part(part); return ret; } static bool disk_unlock_native_capacity(struct gendisk *disk) { const struct block_device_operations *bdops = disk->fops; if (bdops->unlock_native_capacity && !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) { printk(KERN_CONT "enabling native capacity\n"); bdops->unlock_native_capacity(disk); disk->flags |= GENHD_FL_NATIVE_CAPACITY; return true; } else { printk(KERN_CONT "truncated\n"); return false; } } int blk_drop_partitions(struct block_device *bdev) { struct disk_part_iter piter; struct hd_struct *part; if (!disk_part_scan_enabled(bdev->bd_disk)) return 0; if (bdev->bd_part_count) return -EBUSY; sync_blockdev(bdev); invalidate_bdev(bdev); disk_part_iter_init(&piter, bdev->bd_disk, DISK_PITER_INCL_EMPTY); while ((part = disk_part_iter_next(&piter))) delete_partition(bdev->bd_disk, part); disk_part_iter_exit(&piter); return 0; } #ifdef CONFIG_S390 /* for historic reasons in the DASD driver */ EXPORT_SYMBOL_GPL(blk_drop_partitions); #endif static bool blk_add_partition(struct gendisk *disk, struct block_device *bdev, struct parsed_partitions *state, int p) { sector_t size = state->parts[p].size; sector_t from = state->parts[p].from; struct hd_struct *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: %ld\n", disk->disk_name, p, -PTR_ERR(part)); return true; } if (IS_BUILTIN(CONFIG_BLK_DEV_MD) && (state->parts[p].flags & ADDPART_FLAG_RAID)) md_autodetect_dev(part_to_dev(part)->devt); return true; } int blk_add_partitions(struct gendisk *disk, struct block_device *bdev) { struct parsed_partitions *state; int ret = -EAGAIN, p, highest; if (!disk_part_scan_enabled(disk)) return 0; state = check_partition(disk, bdev); 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 (disk->queue->limits.zoned == BLK_ZONED_HM) { 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); /* * Detect the highest partition number and preallocate disk->part_tbl. * This is an optimization and not strictly necessary. */ for (p = 1, highest = 0; p < state->limit; p++) if (state->parts[p].size) highest = p; disk_expand_part_tbl(disk, highest); for (p = 1; p < state->limit; p++) if (!blk_add_partition(disk, bdev, state, p)) goto out_free_state; ret = 0; out_free_state: free_partitions(state); return ret; } void *read_part_sector(struct parsed_partitions *state, sector_t n, Sector *p) { struct address_space *mapping = state->bdev->bd_inode->i_mapping; struct page *page; if (n >= get_capacity(state->bdev->bd_disk)) { state->access_beyond_eod = true; return NULL; } page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT - 9)), NULL); if (IS_ERR(page)) goto out; if (PageError(page)) goto out_put_page; p->v = page; return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << SECTOR_SHIFT); out_put_page: put_page(page); out: p->v = NULL; return NULL; }