Re: [PATCH 2/4] btrfs: tree-checker: Refactor inode key check into seperate function

[Su Yue <Damenly_Su@gmx.com>]

On 2019/12/9 6:54 PM, Qu Wenruo wrote:
> Inode key check is not as easy as several lines, and it will be called
> in more than one location (INODE_ITEM check and
> DIR_ITEM/DIR_INDEX/XATTR_ITEM location key check).
>
> So here refactor such check into check_inode_key().
>
> And add extra checks for XATTR_ITEM.
>
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>   fs/btrfs/tree-checker.c | 77 +++++++++++++++++++++++++++++++----------
>   1 file changed, 59 insertions(+), 18 deletions(-)
>
> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
> index 6cb49c75c5e1..68dad9ec38dd 100644
> --- a/fs/btrfs/tree-checker.c
> +++ b/fs/btrfs/tree-checker.c
> @@ -359,6 +359,60 @@ static int check_csum_item(struct extent_buffer *leaf, struct btrfs_key *key,
>   	return 0;
>   }
>
> +/* Inode item error output has the same format as dir_item_err() */
> +#define inode_item_err(eb, slot, fmt, ...)			\
> +	dir_item_err(eb, slot, fmt, __VA_ARGS__)
> +
> +static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key,
> +			   int slot)

The function name is confusing to me. It checks xattr which is not
inode related obviously.

I saw the 4th patch. How about introduction of new function
check_location_key(), then calls check_root_key() , check_inode_key()
and checks xatrr case inside?

Others in the patchset seem fine to me.


Thanks
> +{
> +	struct btrfs_key item_key;
> +	bool is_inode_item;
> +
> +	btrfs_item_key_to_cpu(leaf, &item_key, slot);
> +	is_inode_item = (item_key.type == BTRFS_INODE_ITEM_KEY);
> +
> +	/* For XATTR_ITEM, location key should be all 0 */
> +	if (item_key.type == BTRFS_XATTR_ITEM_KEY) {
> +		if (key->type != 0 || key->objectid != 0 || key->offset != 0)
> +			return -EUCLEAN;
> +		return 0;
> +	}
> +
> +	if ((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
> +	     key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
> +	    key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
> +	    key->objectid != BTRFS_FREE_INO_OBJECTID) {
> +		if (is_inode_item)
> +			generic_err(leaf, slot,
> +	"invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
> +				key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
> +				BTRFS_FIRST_FREE_OBJECTID,
> +				BTRFS_LAST_FREE_OBJECTID,
> +				BTRFS_FREE_INO_OBJECTID);
> +		else
> +			dir_item_err(leaf, slot,
> +"invalid location key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
> +				key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
> +				BTRFS_FIRST_FREE_OBJECTID,
> +				BTRFS_LAST_FREE_OBJECTID,
> +				BTRFS_FREE_INO_OBJECTID);
> +		return -EUCLEAN;
> +	}
> +	if (key->offset != 0) {
> +		if (is_inode_item)
> +			inode_item_err(leaf, slot,
> +				       "invalid key offset: has %llu expect 0",
> +				       key->offset);
> +		else
> +			dir_item_err(leaf, slot,
> +				"invalid location key offset:has %llu expect 0",
> +				key->offset);
> +		return -EUCLEAN;
> +	}
> +	return 0;
> +}
> +
>   static int check_dir_item(struct extent_buffer *leaf,
>   			  struct btrfs_key *key, struct btrfs_key *prev_key,
>   			  int slot)
> @@ -798,25 +852,12 @@ static int check_inode_item(struct extent_buffer *leaf,
>   	u64 super_gen = btrfs_super_generation(fs_info->super_copy);
>   	u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
>   	u32 mode;
> +	int ret;
> +
> +	ret = check_inode_key(leaf, key, slot);
> +	if (ret < 0)
> +		return ret;
>
> -	if ((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
> -	     key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
> -	    key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
> -	    key->objectid != BTRFS_FREE_INO_OBJECTID) {
> -		generic_err(leaf, slot,
> -	"invalid key objectid: has %llu expect %llu or [%llu, %llu] or %llu",
> -			    key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
> -			    BTRFS_FIRST_FREE_OBJECTID,
> -			    BTRFS_LAST_FREE_OBJECTID,
> -			    BTRFS_FREE_INO_OBJECTID);
> -		return -EUCLEAN;
> -	}
> -	if (key->offset != 0) {
> -		inode_item_err(leaf, slot,
> -			"invalid key offset: has %llu expect 0",
> -			key->offset);
> -		return -EUCLEAN;
> -	}
>   	iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);
>
>   	/* Here we use super block generation + 1 to handle log tree */
>