Re: [PATCH 5/8] btrfs: tree-checker: don't fail on empty extent roots for extent tree v2

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2021/11/6 04:49, Josef Bacik wrote:
> For extent tree v2 we can definitely have empty extent roots, so skip
> this particular check if we have that set.

OK I guess the changes in tree-checker is not yet complete.

As I thought there would be more and bigger changes to support those
global roots.

But so far so good for tree-checker.

Reviewed-by: Qu Wenruo <wqu@suse.com>

Thanks,
Qu
>
> Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> ---
>   fs/btrfs/tree-checker.c | 14 +++++++++++++-
>   1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index 7733e8ac0a69..1c33dd0e4afc 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -1633,7 +1633,6 @@ static int check_leaf(struct extent_buffer *leaf, bool check_item_data)
>   		/* These trees must never be empty */
>   		if (unlikely(owner == BTRFS_ROOT_TREE_OBJECTID ||
>   			     owner == BTRFS_CHUNK_TREE_OBJECTID ||
> -			     owner == BTRFS_EXTENT_TREE_OBJECTID ||
>   			     owner == BTRFS_DEV_TREE_OBJECTID ||
>   			     owner == BTRFS_FS_TREE_OBJECTID ||
>   			     owner == BTRFS_DATA_RELOC_TREE_OBJECTID)) {
> @@ -1642,12 +1641,25 @@ static int check_leaf(struct extent_buffer *leaf, bool check_item_data)
>   				    owner);
>   			return -EUCLEAN;
>   		}
> +
>   		/* Unknown tree */
>   		if (unlikely(owner == 0)) {
>   			generic_err(leaf, 0,
>   				"invalid owner, root 0 is not defined");
>   			return -EUCLEAN;
>   		}
> +
> +		/* EXTENT_TREE_V2 can have empty extent trees. */
> +		if (btrfs_fs_incompat(fs_info, EXTENT_TREE_V2))
> +			return 0;
> +
> +		if (unlikely(owner == BTRFS_EXTENT_TREE_OBJECTID)) {
> +			generic_err(leaf, 0,
> +			"invalid root, root %llu must never be empty",
> +				    owner);
> +			return -EUCLEAN;
> +		}
> +
>   		return 0;
>   	}
>
>