// SPDX-License-Identifier: GPL-2.0 /* * Code extracted from drivers/block/genhd.c * Copyright (C) 1991-1998 Linus Torvalds * Re-organised Feb 1998 Russell King * * We now have independent partition support from the * block drivers, which allows all the partition code to * be grouped in one location, and it to be mostly self * contained. */ #include #include #include #include #include #include #include #include #include "partitions/check.h" #ifdef CONFIG_BLK_DEV_MD extern void md_autodetect_dev(dev_t dev); #endif /* * disk_name() is used by partition check code and the genhd driver. * It formats the devicename of the indicated disk into * the supplied buffer (of size at least 32), and returns * a pointer to that same buffer (for convenience). */ char *disk_name(struct gendisk *hd, int partno, char *buf) { if (!partno) snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name); else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1])) snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno); else snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno); return buf; } const char *bdevname(struct block_device *bdev, char *buf) { return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf); } EXPORT_SYMBOL(bdevname); const char *bio_devname(struct bio *bio, char *buf) { return disk_name(bio->bi_disk, bio->bi_partno, buf); } EXPORT_SYMBOL(bio_devname); /* * There's very little reason to use this, you should really * have a struct block_device just about everywhere and use * bdevname() instead. */ const char *__bdevname(dev_t dev, char *buffer) { scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)", MAJOR(dev), MINOR(dev)); return buffer; } EXPORT_SYMBOL(__bdevname); 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); } ssize_t part_size_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)part_nr_sects_read(p)); } 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); } ssize_t part_stat_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); struct request_queue *q = part_to_disk(p)->queue; unsigned int inflight; inflight = part_in_flight(q, p); return sprintf(buf, "%8lu %8lu %8llu %8u " "%8lu %8lu %8llu %8u " "%8u %8u %8u " "%8lu %8lu %8llu %8u " "%8lu %8u" "\n", part_stat_read(p, ios[STAT_READ]), part_stat_read(p, merges[STAT_READ]), (unsigned long long)part_stat_read(p, sectors[STAT_READ]), (unsigned int)part_stat_read_msecs(p, STAT_READ), part_stat_read(p, ios[STAT_WRITE]), part_stat_read(p, merges[STAT_WRITE]), (unsigned long long)part_stat_read(p, sectors[STAT_WRITE]), (unsigned int)part_stat_read_msecs(p, STAT_WRITE), inflight, jiffies_to_msecs(part_stat_read(p, io_ticks)), jiffies_to_msecs(part_stat_read(p, time_in_queue)), part_stat_read(p, ios[STAT_DISCARD]), part_stat_read(p, merges[STAT_DISCARD]), (unsigned long long)part_stat_read(p, sectors[STAT_DISCARD]), (unsigned int)part_stat_read_msecs(p, STAT_DISCARD), part_stat_read(p, ios[STAT_FLUSH]), (unsigned int)part_stat_read_msecs(p, STAT_FLUSH)); } ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); struct request_queue *q = part_to_disk(p)->queue; unsigned int inflight[2]; part_in_flight_rw(q, p, inflight); return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]); } #ifdef CONFIG_FAIL_MAKE_REQUEST ssize_t part_fail_show(struct device *dev, struct device_attribute *attr, char *buf) { struct hd_struct *p = dev_to_part(dev); return sprintf(buf, "%d\n", p->make_it_fail); } ssize_t part_fail_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct hd_struct *p = dev_to_part(dev); int i; if (count > 0 && sscanf(buf, "%d", &i) > 0) p->make_it_fail = (i == 0) ? 0 : 1; return count; } #endif 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 delete_partition_work_fn(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)); } void __delete_partition(struct percpu_ref *ref) { struct hd_struct *part = container_of(ref, struct hd_struct, ref); INIT_RCU_WORK(&part->rcu_work, delete_partition_work_fn); queue_rcu_work(system_wq, &part->rcu_work); } /* * 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, int partno) { struct disk_part_tbl *ptbl = rcu_dereference_protected(disk->part_tbl, 1); struct hd_struct *part; if (partno >= ptbl->len) return; part = rcu_dereference_protected(ptbl->part[partno], 1); if (!part) return; rcu_assign_pointer(ptbl->part[partno], NULL); rcu_assign_pointer(ptbl->last_lookup, 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)); hd_struct_kill(part); } 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. */ 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; 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); if (!init_part_stats(p)) { err = -ENOMEM; goto out_free; } seqcount_init(&p->nr_sects_seq); 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 = alloc_part_info(disk); 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: free_part_info(p); out_free_stats: free_part_stats(p); 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 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 gendisk *disk, struct block_device *bdev) { struct disk_part_iter piter; struct hd_struct *part; int res; if (!disk_part_scan_enabled(disk)) return 0; if (bdev->bd_part_count || bdev->bd_super) return -EBUSY; res = invalidate_partition(disk, 0); if (res) return res; disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); while ((part = disk_part_iter_next(&piter))) delete_partition(disk, part->partno); disk_part_iter_exit(&piter); return 0; } 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)) { printk(KERN_ERR " %s: p%d could not be added: %ld\n", disk->disk_name, p, -PTR_ERR(part)); return true; } #ifdef CONFIG_BLK_DEV_MD if (state->parts[p].flags & ADDPART_FLAG_RAID) md_autodetect_dev(part_to_dev(part)->devt); #endif 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 zoned block devices. */ if (bdev_is_zoned(bdev)) { pr_warn("%s: ignoring partition table on 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; } unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p) { struct address_space *mapping = bdev->bd_inode->i_mapping; struct page *page; page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)), NULL); if (!IS_ERR(page)) { if (PageError(page)) goto fail; p->v = page; return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << 9); fail: put_page(page); } p->v = NULL; return NULL; } EXPORT_SYMBOL(read_dev_sector);