Re: [PATCH 02/37] libext2fs: Add metadata checksum flag

[Andreas Dilger <aedilger@gmail.com>]

On 2011-08-31, at 6:35 PM, "Darrick J. Wong" <djwong@us.ibm.com> wrote:
> Add a feature flag to enable metadata checksumming in e2fsprogs.  Also add a
> runtime flag to disable checksum verification; this flag will be used by
> debugfs to salvage filesystems and tune2fs when resetting checksums.
> 
> Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
> ---
> lib/blkid/probe.h    |    1 +
> lib/e2p/feature.c    |    2 ++
> lib/ext2fs/ext2_fs.h |    1 +
> lib/ext2fs/ext2fs.h  |    4 +++-
> 4 files changed, 7 insertions(+), 1 deletions(-)
> 
> 
> diff --git a/lib/blkid/probe.h b/lib/blkid/probe.h
> index 37e80ef..d6809e1 100644
> --- a/lib/blkid/probe.h
> +++ b/lib/blkid/probe.h
> @@ -110,6 +110,7 @@ struct ext2_super_block {
> #define EXT4_FEATURE_RO_COMPAT_DIR_NLINK    0x0020
> #define EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE    0x0040
> #define EXT4_FEATURE_RO_COMPAT_QUOTA        0x0100
> +#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400

There is really no reason to add every feature flag to probe.h. This was only used for distinguishing ext2/3/4. The blkid code officially lives in util-linux anyway.  Probably better to remove the ones that are not actually used. 

> /* for s_feature_incompat */
> #define EXT2_FEATURE_INCOMPAT_FILETYPE        0x0002
> diff --git a/lib/e2p/feature.c b/lib/e2p/feature.c
> index 16fba53..07b700d 100644
> --- a/lib/e2p/feature.c
> +++ b/lib/e2p/feature.c
> @@ -59,6 +59,8 @@ static struct feature feature_list[] = {
>            "quota" },
>    {    E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_BIGALLOC,
>            "bigalloc"},
> +    {    E2P_FEATURE_RO_INCOMPAT, EXT4_FEATURE_RO_COMPAT_METADATA_CSUM,
> +            "metadata_csum"},
> 
>    {    E2P_FEATURE_INCOMPAT, EXT2_FEATURE_INCOMPAT_COMPRESSION,
>            "compression" },
> diff --git a/lib/ext2fs/ext2_fs.h b/lib/ext2fs/ext2_fs.h
> index e342bf0..ae7662e 100644
> --- a/lib/ext2fs/ext2_fs.h
> +++ b/lib/ext2fs/ext2_fs.h
> @@ -635,6 +635,7 @@ struct ext2_super_block {
> #define EXT4_FEATURE_RO_COMPAT_HAS_SNAPSHOT    0x0080
> #define EXT4_FEATURE_RO_COMPAT_QUOTA        0x0100
> #define EXT4_FEATURE_RO_COMPAT_BIGALLOC        0x0200
> +#define EXT4_FEATURE_RO_COMPAT_METADATA_CSUM    0x0400
> 
> #define EXT2_FEATURE_INCOMPAT_COMPRESSION    0x0001
> #define EXT2_FEATURE_INCOMPAT_FILETYPE        0x0002
> diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
> index b290a1f..e638169 100644
> --- a/lib/ext2fs/ext2fs.h
> +++ b/lib/ext2fs/ext2fs.h
> @@ -195,6 +195,7 @@ typedef struct ext2_file *ext2_file_t;
> #define EXT2_FLAG_64BITS        0x20000
> #define EXT2_FLAG_PRINT_PROGRESS    0x40000
> #define EXT2_FLAG_DIRECT_IO        0x80000
> +#define EXT2_FLAG_IGNORE_CSUM_ERRORS    0x100000
> 
> /*
>  * Special flag in the ext2 inode i_flag field that means that this is
> @@ -564,7 +565,8 @@ typedef struct ext2_icount *ext2_icount_t;
>                     EXT4_FEATURE_RO_COMPAT_DIR_NLINK|\
>                     EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE|\
>                     EXT4_FEATURE_RO_COMPAT_GDT_CSUM|\
> -                     EXT4_FEATURE_RO_COMPAT_BIGALLOC)
> +                     EXT4_FEATURE_RO_COMPAT_BIGALLOC|\
> +                     EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)
> 
> /*
>  * These features are only allowed if EXT2_FLAG_SOFTSUPP_FEATURES is passed
> 
> --
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