- u32 sectorsize;
- u32 nodesize;
- u32 leafsize;
- u32 blocksize;
- u32 stripesize;
- u64 generation;
- struct btrfs_root *tree_root = malloc(sizeof(struct btrfs_root));
- struct btrfs_root *extent_root = malloc(sizeof(struct btrfs_root));
- struct btrfs_root *chunk_root = malloc(sizeof(struct btrfs_root));
- struct btrfs_root *dev_root = malloc(sizeof(struct btrfs_root));
- struct btrfs_root *csum_root = malloc(sizeof(struct btrfs_root));
- struct btrfs_fs_info *fs_info = malloc(sizeof(*fs_info));
- int ret;
- struct btrfs_super_block *disk_super;
- struct btrfs_fs_devices *fs_devices = NULL;
- u64 total_devs;
- u64 features;
-
- ret = btrfs_scan_one_device(fd, device, &fs_devices,
- &total_devs, BTRFS_SUPER_INFO_OFFSET);
-
- if (ret) {
- fprintf(stderr, "No valid Btrfs found on %s\n", device);
- goto out;
- }
-
- if (total_devs != 1) {
- ret = btrfs_scan_for_fsid(fs_devices, total_devs, 1);
- if (ret)
- goto out;
- }
-
- memset(fs_info, 0, sizeof(*fs_info));
- fs_info->super_copy = calloc(1, BTRFS_SUPER_INFO_SIZE);
- fs_info->tree_root = tree_root;
- fs_info->extent_root = extent_root;
- fs_info->chunk_root = chunk_root;
- fs_info->dev_root = dev_root;
- fs_info->csum_root = csum_root;
-
- fs_info->readonly = 1;
-
- extent_io_tree_init(&fs_info->extent_cache);
- extent_io_tree_init(&fs_info->free_space_cache);
- extent_io_tree_init(&fs_info->block_group_cache);
- extent_io_tree_init(&fs_info->pinned_extents);
- extent_io_tree_init(&fs_info->pending_del);
- extent_io_tree_init(&fs_info->extent_ins);
- cache_tree_init(&fs_info->fs_root_cache);
-
- cache_tree_init(&fs_info->mapping_tree.cache_tree);
-
- mutex_init(&fs_info->fs_mutex);
- fs_info->fs_devices = fs_devices;
- INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
- INIT_LIST_HEAD(&fs_info->space_info);
-
- __setup_root(4096, 4096, 4096, 4096, tree_root,
- fs_info, BTRFS_ROOT_TREE_OBJECTID);
-
- ret = btrfs_open_devices(fs_devices, O_RDONLY);
- if (ret)
- goto out_cleanup;
-
- fs_info->super_bytenr = BTRFS_SUPER_INFO_OFFSET;
- disk_super = fs_info->super_copy;
- ret = btrfs_read_dev_super(fs_devices->latest_bdev,
- disk_super, BTRFS_SUPER_INFO_OFFSET);
- if (ret) {
- printk("No valid btrfs found\n");
- goto out_devices;
- }
-
- memcpy(fs_info->fsid, &disk_super->fsid, BTRFS_FSID_SIZE);
-
-
- features = btrfs_super_incompat_flags(disk_super) &
- ~BTRFS_FEATURE_INCOMPAT_SUPP;
- if (features) {
- printk("couldn't open because of unsupported "
- "option features (%Lx).\n", features);
- goto out_devices;
- }
-
- features = btrfs_super_incompat_flags(disk_super);
- if (!(features & BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF)) {
- features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
- btrfs_set_super_incompat_flags(disk_super, features);
- }
-
- nodesize = btrfs_super_nodesize(disk_super);
- leafsize = btrfs_super_leafsize(disk_super);
- sectorsize = btrfs_super_sectorsize(disk_super);
- stripesize = btrfs_super_stripesize(disk_super);
- tree_root->nodesize = nodesize;
- tree_root->leafsize = leafsize;
- tree_root->sectorsize = sectorsize;
- tree_root->stripesize = stripesize;
-
- ret = btrfs_read_sys_array(tree_root);
- if (ret)
- goto out_devices;
- blocksize = btrfs_level_size(tree_root,
- btrfs_super_chunk_root_level(disk_super));
- generation = btrfs_super_chunk_root_generation(disk_super);
-
- __setup_root(nodesize, leafsize, sectorsize, stripesize,
- chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
-
- chunk_root->node = read_tree_block(chunk_root,
- btrfs_super_chunk_root(disk_super),
- blocksize, generation);
- if (!chunk_root->node) {
- printk("Couldn't read chunk root\n");
- goto out_devices;
- }
-
- read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
- (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
- BTRFS_UUID_SIZE);
-
- if (!(btrfs_super_flags(disk_super) & BTRFS_SUPER_FLAG_METADUMP)) {
- ret = btrfs_read_chunk_tree(chunk_root);
- if (ret)
- goto out_chunk;
- }
-
- return fs_info->chunk_root;
-out_chunk:
- free_extent_buffer(fs_info->chunk_root->node);
-out_devices:
- close_all_devices(fs_info);
-out_cleanup:
- extent_io_tree_cleanup(&fs_info->extent_cache);
- extent_io_tree_cleanup(&fs_info->free_space_cache);
- extent_io_tree_cleanup(&fs_info->block_group_cache);
- extent_io_tree_cleanup(&fs_info->pinned_extents);
- extent_io_tree_cleanup(&fs_info->pending_del);
- extent_io_tree_cleanup(&fs_info->extent_ins);
-out:
- free(tree_root);
- free(extent_root);
- free(chunk_root);
- free(dev_root);
- free(csum_root);
- free(fs_info);
- return NULL;