Now that we have already checked for a valid checksum type before calling btrfs_check_super_csum(), it can be simplified even further.
While at it get rid of the implicit size assumption of the resulting checksum as well. Signed-off-by: Johannes Thumshirn <jthumsh...@suse.de> Reviewed-by: Nikolay Borisov <nbori...@suse.com> --- Changes to v1: - Check for disk_sb->csum instead of raw buffer (Nikolay) --- fs/btrfs/disk-io.c | 37 +++++++++++++------------------------ 1 file changed, 13 insertions(+), 24 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 74937effaed4..edb8bc79b01b 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -375,33 +375,22 @@ static int btrfs_check_super_csum(struct btrfs_fs_info *fs_info, { struct btrfs_super_block *disk_sb = (struct btrfs_super_block *)raw_disk_sb; - 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)]; + u32 crc = ~(u32)0; + char result[BTRFS_CSUM_SIZE]; - /* - * The super_block structure does not span the whole - * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space - * is filled with zeros and is included in the checksum. - */ - crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE, - crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); - btrfs_csum_final(crc, result); + /* + * The super_block structure does not span the whole + * BTRFS_SUPER_INFO_SIZE range, we expect that the unused space + * is filled with zeros and is included in the checksum. + */ + crc = btrfs_csum_data(raw_disk_sb + BTRFS_CSUM_SIZE, + crc, BTRFS_SUPER_INFO_SIZE - BTRFS_CSUM_SIZE); + btrfs_csum_final(crc, result); - if (memcmp(raw_disk_sb, result, sizeof(result))) - ret = 1; - } + if (memcmp(disk_sb->csum, result, btrfs_super_csum_size(disk_sb))) + return 1; - return ret; + return 0; } int btrfs_verify_level_key(struct extent_buffer *eb, int level, -- 2.16.4