예제 #1
0
/*
 * resolve an indirect backref in the form (root_id, key, level)
 * to a logical address
 */
static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info,
				  struct btrfs_path *path, u64 time_seq,
				  struct __prelim_ref *ref,
				  struct ulist *parents,
				  const u64 *extent_item_pos, u64 total_refs)
{
	struct btrfs_root *root;
	struct btrfs_key root_key;
	struct extent_buffer *eb;
	int ret = 0;
	int root_level;
	int level = ref->level;

	root_key.objectid = ref->root_id;
	root_key.type = BTRFS_ROOT_ITEM_KEY;
	root_key.offset = (u64)-1;

	root = btrfs_read_fs_root(fs_info, &root_key);
	if (IS_ERR(root)) {
		ret = PTR_ERR(root);
		goto out;
	}

	root_level = btrfs_root_level(&root->root_item);

	if (root_level + 1 == level)
		goto out;

	path->lowest_level = level;
	ret = btrfs_search_slot(NULL, root, &ref->key_for_search, path, 0, 0);

	pr_debug("search slot in root %llu (level %d, ref count %d) returned "
		 "%d for key (%llu %u %llu)\n",
		 ref->root_id, level, ref->count, ret,
		 ref->key_for_search.objectid, ref->key_for_search.type,
		 ref->key_for_search.offset);
	if (ret < 0)
		goto out;

	eb = path->nodes[level];
	while (!eb) {
		if (!level) {
			ret = 1;
			WARN_ON(1);
			goto out;
		}
		level--;
		eb = path->nodes[level];
	}

	ret = add_all_parents(root, path, parents, ref, level, time_seq,
			      extent_item_pos, total_refs);
out:
	path->lowest_level = 0;
	btrfs_release_path(path);
	return ret;
}
예제 #2
0
static struct btrfs_fs_info *__open_ctree_fd(int fp, const char *path,
					     u64 sb_bytenr,
					     u64 root_tree_bytenr, int writes,
					     int partial)
{
	u32 sectorsize;
	u32 nodesize;
	u32 leafsize;
	u32 blocksize;
	u32 stripesize;
	u64 generation;
	struct btrfs_key key;
	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;

	if (sb_bytenr == 0)
		sb_bytenr = BTRFS_SUPER_INFO_OFFSET;

	/* try to drop all the caches */
	if (posix_fadvise(fp, 0, 0, POSIX_FADV_DONTNEED))
		fprintf(stderr, "Warning, could not drop caches\n");

	ret = btrfs_scan_one_device(fp, path, &fs_devices,
				    &total_devs, sb_bytenr);

	if (ret) {
		fprintf(stderr, "No valid Btrfs found on %s\n", path);
		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;

	if (!writes)
		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);

	if (writes)
		ret = btrfs_open_devices(fs_devices, O_RDWR);
	else
		ret = btrfs_open_devices(fs_devices, O_RDONLY);
	if (ret)
		goto out_cleanup;

	fs_info->super_bytenr = sb_bytenr;
	disk_super = fs_info->super_copy;
	ret = btrfs_read_dev_super(fs_devices->latest_bdev,
				   disk_super, sb_bytenr);
	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",
		       (unsigned long long)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);
	}

	features = btrfs_super_compat_ro_flags(disk_super) &
		~BTRFS_FEATURE_COMPAT_RO_SUPP;
	if (writes && features) {
		printk("couldn't open RDWR because of unsupported "
		       "option features (%Lx).\n",
		       (unsigned long long)features);
		goto out_devices;
	}

	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 (!extent_buffer_uptodate(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) {
			printk("Couldn't read chunk tree\n");
			goto out_chunk;
		}
	}

	blocksize = btrfs_level_size(tree_root,
				     btrfs_super_root_level(disk_super));
	generation = btrfs_super_generation(disk_super);

	if (!root_tree_bytenr)
		root_tree_bytenr = btrfs_super_root(disk_super);
	tree_root->node = read_tree_block(tree_root,
					  root_tree_bytenr,
					  blocksize, generation);
	if (!extent_buffer_uptodate(tree_root->node)) {
		printk("Couldn't read tree root\n");
		goto out_failed;
	}
	ret = find_and_setup_root(tree_root, fs_info,
				  BTRFS_EXTENT_TREE_OBJECTID, extent_root);
	if (ret) {
		printk("Couldn't setup extent tree\n");
		goto out_failed;
	}
	extent_root->track_dirty = 1;

	ret = find_and_setup_root(tree_root, fs_info,
				  BTRFS_DEV_TREE_OBJECTID, dev_root);
	if (ret) {
		printk("Couldn't setup device tree\n");
		goto out_failed;
	}
	dev_root->track_dirty = 1;

	ret = find_and_setup_root(tree_root, fs_info,
				  BTRFS_CSUM_TREE_OBJECTID, csum_root);
	if (ret) {
		printk("Couldn't setup csum tree\n");
		if (!partial)
			goto out_failed;
	}
	csum_root->track_dirty = 1;

	find_and_setup_log_root(tree_root, fs_info, disk_super);

	fs_info->generation = generation;
	fs_info->last_trans_committed = generation;
	btrfs_read_block_groups(fs_info->tree_root);

	key.objectid = BTRFS_FS_TREE_OBJECTID;
	key.type = BTRFS_ROOT_ITEM_KEY;
	key.offset = (u64)-1;
	fs_info->fs_root = btrfs_read_fs_root(fs_info, &key);

	if (!fs_info->fs_root)
		goto out_failed;

	fs_info->data_alloc_profile = (u64)-1;
	fs_info->metadata_alloc_profile = (u64)-1;
	fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;

	return fs_info;

out_failed:
	if (partial)
		return fs_info;

	if (fs_info->csum_root)
		free_extent_buffer(fs_info->csum_root->node);
	if (fs_info->dev_root)
		free_extent_buffer(fs_info->dev_root->node);
	if (fs_info->extent_root)
		free_extent_buffer(fs_info->extent_root->node);
	if (fs_info->tree_root)
		free_extent_buffer(fs_info->tree_root->node);
out_chunk:
	if (fs_info->chunk_root)
		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;
}