Btrfs: send, avoid unnecessary inode item lookup in the btree (b46ab97b) · Commits · 戴 / test

Regardless of whether the caller is interested or not in knowing the inode's generation (dir_gen != NULL), get_first_ref always does a btree lookup to get the inode item. Avoid this useless lookup if dir_gen parameter is NULL (which is in some cases). Signed-off-by:

Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by:

Chris Mason <clm@fb.com>

fs/btrfs/send.c

+7 −6

Original line number	Diff line number	Diff line
		@@ -1693,10 +1693,12 @@ static int get_first_ref(struct btrfs_root *root, u64 ino,
		goto out;
		btrfs_release_path(path);

		ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL, NULL,
		NULL, NULL);
		if (dir_gen) {
		ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL,
		NULL, NULL, NULL);
		if (ret < 0)
		goto out;
		}

		*dir = parent_dir;

		@@ -1712,13 +1714,12 @@ static int is_first_ref(struct btrfs_root *root,
		int ret;
		struct fs_path *tmp_name;
		u64 tmp_dir;
		u64 tmp_dir_gen;

		tmp_name = fs_path_alloc();
		if (!tmp_name)
		return -ENOMEM;

		ret = get_first_ref(root, ino, &tmp_dir, &tmp_dir_gen, tmp_name);
		ret = get_first_ref(root, ino, &tmp_dir, NULL, tmp_name);
		if (ret < 0)
		goto out;

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