int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info)
{
    struct btrfs_trans_handle *trans;
    struct btrfs_root *tree_root = fs_info->tree_root;
    struct btrfs_root *free_space_root;
    struct btrfs_block_group_cache *block_group;
    struct rb_node *node;
    int ret;

    trans = btrfs_start_transaction(tree_root, 0);
    if (IS_ERR(trans))
        return PTR_ERR(trans);

    fs_info->creating_free_space_tree = 1;
    free_space_root = btrfs_create_tree(trans, fs_info,
                                        BTRFS_FREE_SPACE_TREE_OBJECTID);
    if (IS_ERR(free_space_root)) {
        ret = PTR_ERR(free_space_root);
        goto abort;
    }
    fs_info->free_space_root = free_space_root;

    node = rb_first(&fs_info->block_group_cache_tree);
    while (node) {
        block_group = rb_entry(node, struct btrfs_block_group_cache,
                               cache_node);
        ret = populate_free_space_tree(trans, fs_info, block_group);
        if (ret)
            goto abort;
        node = rb_next(node);
    }

    btrfs_set_fs_compat_ro(fs_info, FREE_SPACE_TREE);
    fs_info->creating_free_space_tree = 0;

    ret = btrfs_commit_transaction(trans, tree_root);
    if (ret)
        return ret;

    return 0;

abort:
    fs_info->creating_free_space_tree = 0;
    btrfs_abort_transaction(trans, ret);
    btrfs_end_transaction(trans, tree_root);
    return ret;
}
Ejemplo n.º 2
0
int btrfs_dedup_enable(struct btrfs_fs_info *fs_info, u16 type, u16 backend,
		       u64 blocksize, u64 limit)
{
	struct btrfs_dedup_info *dedup_info;
	struct btrfs_root *dedup_root;
	struct btrfs_key key;
	struct btrfs_trans_handle *trans;
	struct btrfs_path *path;
	struct btrfs_dedup_status_item *status;
	int create_tree;
	u64 compat_ro_flag = btrfs_super_compat_ro_flags(fs_info->super_copy);
	int ret = 0;

	/* Sanity check */
	if (blocksize > BTRFS_DEDUP_BLOCKSIZE_MAX ||
	    blocksize < BTRFS_DEDUP_BLOCKSIZE_MIN ||
	    blocksize < fs_info->tree_root->sectorsize ||
	    !is_power_of_2(blocksize))
		return -EINVAL;
	if (type > ARRAY_SIZE(btrfs_dedup_sizes))
		return -EINVAL;
	if (backend >= BTRFS_DEDUP_BACKEND_LAST)
		return -EINVAL;
	if (backend == BTRFS_DEDUP_BACKEND_INMEMORY && limit == 0)
		limit = 4096; /* default value */
	if (backend == BTRFS_DEDUP_BACKEND_ONDISK && limit != 0)
		limit = 0;

	/*
	 * If current fs doesn't support DEDUP feature, don't enable
	 * on-disk dedup.
	 */
	if (!(compat_ro_flag & BTRFS_FEATURE_COMPAT_RO_DEDUP) &&
	    backend == BTRFS_DEDUP_BACKEND_ONDISK)
		return -EINVAL;

	/* Meaningless and unable to enable dedup for RO fs */
	if (fs_info->sb->s_flags & MS_RDONLY)
		return -EINVAL;

	if (fs_info->dedup_info) {
		dedup_info = fs_info->dedup_info;

		/* Check if we are re-enable for different dedup config */
		if (dedup_info->blocksize != blocksize ||
		    dedup_info->hash_type != type ||
		    dedup_info->backend != backend) {
			btrfs_dedup_disable(fs_info);
			goto enable;
		}

		/* On-fly limit change is OK */
		mutex_lock(&dedup_info->lock);
		fs_info->dedup_info->limit_nr = limit;
		mutex_unlock(&dedup_info->lock);
		return 0;
	}

enable:
	create_tree = compat_ro_flag & BTRFS_FEATURE_COMPAT_RO_DEDUP;

	ret = init_dedup_info(fs_info, type, backend, blocksize, limit);
	dedup_info = fs_info->dedup_info;
	if (ret < 0)
		goto out;

	if (!create_tree)
		goto out;

	/* Create dedup tree for status at least */
	path = btrfs_alloc_path();
	if (!path) {
		ret = -ENOMEM;
		goto out;
	}

	trans = btrfs_start_transaction(fs_info->tree_root, 2);
	if (IS_ERR(trans)) {
		ret = PTR_ERR(trans);
		btrfs_free_path(path);
		goto out;
	}

	dedup_root = btrfs_create_tree(trans, fs_info,
				       BTRFS_DEDUP_TREE_OBJECTID);
	if (IS_ERR(dedup_root)) {
		ret = PTR_ERR(dedup_root);
		btrfs_abort_transaction(trans, fs_info->tree_root, ret);
		btrfs_free_path(path);
		goto out;
	}

	dedup_info->dedup_root = dedup_root;

	key.objectid = 0;
	key.type = BTRFS_DEDUP_STATUS_ITEM_KEY;
	key.offset = 0;

	ret = btrfs_insert_empty_item(trans, dedup_root, path, &key,
				      sizeof(*status));
	if (ret < 0) {
		btrfs_abort_transaction(trans, fs_info->tree_root, ret);
		btrfs_free_path(path);
		goto out;
	}
	status = btrfs_item_ptr(path->nodes[0], path->slots[0],
				struct btrfs_dedup_status_item);
	btrfs_set_dedup_status_blocksize(path->nodes[0], status, blocksize);
	btrfs_set_dedup_status_limit(path->nodes[0], status, limit);
	btrfs_set_dedup_status_hash_type(path->nodes[0], status, type);
	btrfs_set_dedup_status_backend(path->nodes[0], status, backend);
	btrfs_mark_buffer_dirty(path->nodes[0]);

	btrfs_free_path(path);
	ret = btrfs_commit_transaction(trans, fs_info->tree_root);

out:
	if (ret < 0) {
		kfree(dedup_info);
		fs_info->dedup_info = NULL;
	}
	return ret;
}