Re: [PATCH 09/17] btrfs: add common checksum type validation

[Nikolay Borisov <nborisov@suse.com>]

On 10.05.19 г. 14:15 ч., Johannes Thumshirn wrote:
> Currently btrfs is only supporting CRC32C as checksumming algorithm. As
> this is about to change provide a function to validate the checksum type in
> the superblock against all possible algorithms.
> 
> This makes adding new algorithms easier as there are fewer places to adjust
> when adding new algorithms.
> 
> Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  fs/btrfs/disk-io.c | 24 +++++++++++++++++-------
>  1 file changed, 17 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> index 663efce22d98..ab13282d91d2 100644
> --- a/fs/btrfs/disk-io.c
> +++ b/fs/btrfs/disk-io.c
> @@ -356,6 +356,16 @@ static int verify_parent_transid(struct extent_io_tree *io_tree,
>  	return ret;
>  }
>  
> +static bool btrfs_supported_super_csum(struct btrfs_super_block *sb)
> +{
> +	switch (btrfs_super_csum_type(sb)) {
> +	case BTRFS_CSUM_TYPE_CRC32:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
>  /*
>   * Return 0 if the superblock checksum type matches the checksum value of that
>   * algorithm. Pass the raw disk superblock data.
> @@ -368,6 +378,12 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  	u16 csum_type = btrfs_super_csum_type(disk_sb);
>  	int ret = 0;
>  
> +	if (!btrfs_supported_super_csum(disk_sb)) {
> +		btrfs_err(fs_info, "unsupported checksum algorithm %u",
> +			  csum_type);
> +		ret = 1;
> +	}
> +
>  	if (csum_type == BTRFS_CSUM_TYPE_CRC32) {
>  		u32 crc = ~(u32)0;
>  		char result[sizeof(crc)];
> @@ -385,12 +401,6 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info,
>  			ret = 1;
>  	}
>  
> -	if (csum_type >= ARRAY_SIZE(btrfs_csum_sizes)) {
> -		btrfs_err(fs_info, "unsupported checksum algorithm %u",
> -				csum_type);
> -		ret = 1;
> -	}
> -
>  	return ret;
>  }
>  
> @@ -2577,7 +2587,7 @@ static int btrfs_validate_write_super(struct btrfs_fs_info *fs_info,
>  	ret = validate_super(fs_info, sb, -1);
>  	if (ret < 0)
>  		goto out;
> -	if (btrfs_super_csum_type(sb) != BTRFS_CSUM_TYPE_CRC32) {
> +	if (!btrfs_supported_super_csum(sb)) {
>  		ret = -EUCLEAN;
>  		btrfs_err(fs_info, "invalid csum type, has %u want %u",
>  			  btrfs_super_csum_type(sb), BTRFS_CSUM_TYPE_CRC32);
>