/* * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include "kerncompat.h" #include #include #include #include #include #include #include #include "kernel-lib/sizes.h" #include "kernel-shared/accessors.h" #include "kernel-shared/extent_io.h" #include "kernel-shared/uapi/btrfs.h" #include "kernel-shared/uapi/btrfs_tree.h" #include "kernel-shared/ctree.h" #include "kernel-shared/disk-io.h" #include "crypto/crc32c.h" #include "common/device-utils.h" #include "common/messages.h" #include "image/metadump.h" #include "image/common.h" const struct dump_version dump_versions[] = { /* * The original format, which only supports tree blocks and free space * cache dump. */ { .version = 0, .max_pending_size = SZ_256K, .magic_cpu = 0xbd5c25e27295668bULL, .extra_sb_flags = 1 }, #if EXPERIMENTAL /* * The new format, with much larger item size to contain any data * extents. */ { .version = 1, .max_pending_size = SZ_256M, .magic_cpu = 0x31765f506d55445fULL, /* ascii _DUmP_v1, no null */ .extra_sb_flags = 0 }, #endif }; const struct dump_version *current_version = &dump_versions[0]; int detect_version(FILE *in) { struct meta_cluster *cluster; u8 buf[IMAGE_BLOCK_SIZE]; bool found = false; int i; int ret; if (fseek(in, 0, SEEK_SET) < 0) { error("seek failed: %m"); return -errno; } ret = fread(buf, IMAGE_BLOCK_SIZE, 1, in); if (!ret) { error("failed to read header"); return -EIO; } fseek(in, 0, SEEK_SET); cluster = (struct meta_cluster *)buf; for (i = 0; i < ARRAY_SIZE(dump_versions); i++) { if (le64_to_cpu(cluster->header.magic) == dump_versions[i].magic_cpu) { found = true; current_version = &dump_versions[i]; break; } } if (!found) { error("unrecognized header format"); return -EINVAL; } return 0; } void csum_block(u8 *buf, size_t len) { u16 csum_size = btrfs_csum_type_size(BTRFS_CSUM_TYPE_CRC32); u8 result[csum_size]; u32 crc = ~(u32)0; crc = crc32c(crc, buf + BTRFS_CSUM_SIZE, len - BTRFS_CSUM_SIZE); put_unaligned_le32(~crc, result); memcpy(buf, result, csum_size); } void write_backup_supers(int fd, u8 *buf) { struct btrfs_super_block *super = (struct btrfs_super_block *)buf; struct stat st; u64 size; u64 bytenr; int i; int ret; if (fstat(fd, &st)) { error( "cannot stat restore point, won't be able to write backup supers: %m"); return; } size = device_get_partition_size_fd_stat(fd, &st); for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); if (bytenr + BTRFS_SUPER_INFO_SIZE > size) break; btrfs_set_super_bytenr(super, bytenr); csum_block(buf, BTRFS_SUPER_INFO_SIZE); ret = pwrite(fd, buf, BTRFS_SUPER_INFO_SIZE, bytenr); if (ret < BTRFS_SUPER_INFO_SIZE) { if (ret < 0) error( "problem writing out backup super block %d: %m", i); else error("short write writing out backup super block"); break; } } } int update_disk_super_on_device(struct btrfs_fs_info *info, const char *other_dev, u64 cur_devid) { struct btrfs_key key; struct extent_buffer *leaf; struct btrfs_path path = { 0 }; struct btrfs_dev_item *dev_item; struct btrfs_super_block disk_super; char dev_uuid[BTRFS_UUID_SIZE]; char fs_uuid[BTRFS_UUID_SIZE]; u64 devid, type, io_align, io_width; u64 sector_size, total_bytes, bytes_used; int fp = -1; int ret; key.objectid = BTRFS_DEV_ITEMS_OBJECTID; key.type = BTRFS_DEV_ITEM_KEY; key.offset = cur_devid; ret = btrfs_search_slot(NULL, info->chunk_root, &key, &path, 0, 0); if (ret) { error("search key failed: %d", ret); ret = -EIO; goto out; } leaf = path.nodes[0]; dev_item = btrfs_item_ptr(leaf, path.slots[0], struct btrfs_dev_item); devid = btrfs_device_id(leaf, dev_item); if (devid != cur_devid) { error("devid mismatch: %llu != %llu", devid, cur_devid); ret = -EIO; goto out; } type = btrfs_device_type(leaf, dev_item); io_align = btrfs_device_io_align(leaf, dev_item); io_width = btrfs_device_io_width(leaf, dev_item); sector_size = btrfs_device_sector_size(leaf, dev_item); total_bytes = btrfs_device_total_bytes(leaf, dev_item); bytes_used = btrfs_device_bytes_used(leaf, dev_item); read_extent_buffer(leaf, dev_uuid, (unsigned long)btrfs_device_uuid(dev_item), BTRFS_UUID_SIZE); read_extent_buffer(leaf, fs_uuid, (unsigned long)btrfs_device_fsid(dev_item), BTRFS_UUID_SIZE); btrfs_release_path(&path); printf("update disk super on %s devid=%llu\n", other_dev, devid); /* update other devices' super block */ fp = open(other_dev, O_CREAT | O_RDWR, 0600); if (fp < 0) { error("could not open %s: %m", other_dev); ret = -EIO; goto out; } memcpy(&disk_super, info->super_copy, BTRFS_SUPER_INFO_SIZE); dev_item = &disk_super.dev_item; btrfs_set_stack_device_type(dev_item, type); btrfs_set_stack_device_id(dev_item, devid); btrfs_set_stack_device_total_bytes(dev_item, total_bytes); btrfs_set_stack_device_bytes_used(dev_item, bytes_used); btrfs_set_stack_device_io_align(dev_item, io_align); btrfs_set_stack_device_io_width(dev_item, io_width); btrfs_set_stack_device_sector_size(dev_item, sector_size); memcpy(dev_item->uuid, dev_uuid, BTRFS_UUID_SIZE); memcpy(dev_item->fsid, fs_uuid, BTRFS_UUID_SIZE); csum_block((u8 *)&disk_super, BTRFS_SUPER_INFO_SIZE); ret = pwrite(fp, &disk_super, BTRFS_SUPER_INFO_SIZE, BTRFS_SUPER_INFO_OFFSET); if (ret != BTRFS_SUPER_INFO_SIZE) { if (ret < 0) { errno = ret; error("cannot write superblock: %m"); } else { error("cannot write superblock"); } ret = -EIO; goto out; } write_backup_supers(fp, (u8 *)&disk_super); out: if (fp != -1) close(fp); return ret; }