| Message ID | 20190510111547.15310-12-jthumshirn@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add support for SHA-256 checksums | expand |
On 10.05.19 г. 14:15 ч., Johannes Thumshirn wrote: > 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 <jthumshirn@suse.de> Reviewed-by: Nikolay Borisov <nborisov@suse.com> , albeit one small nit below. > --- > 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..21ae9daf52b7 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(raw_disk_sb, result, btrfs_super_csum_size(disk_sb))) nit: I'd rather have the on-disk csum be referred to as : disk_sb->csum it's more self-documenting. > + return 1; > > - return ret; > + return 0; > } > > int btrfs_verify_level_key(struct extent_buffer *eb, int level, >
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 74937effaed4..21ae9daf52b7 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(raw_disk_sb, result, btrfs_super_csum_size(disk_sb))) + return 1; - return ret; + return 0; } int btrfs_verify_level_key(struct extent_buffer *eb, int level,
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 <jthumshirn@suse.de> --- fs/btrfs/disk-io.c | 37 +++++++++++++------------------------ 1 file changed, 13 insertions(+), 24 deletions(-)