[prev in list] [next in list] [prev in thread] [next in thread] 

List:       linux-ext4
Subject:    Re: [PATCH, E2FSPROGS] On-disk format definition group desciptor checksums
From:       Andreas Dilger <adilger () clusterfs ! com>
Date:       2006-10-18 19:28:37
Message-ID: 20061018192837.GE3509 () schatzie ! adilger ! int
[Download RAW message or body]

On Oct 18, 2006  02:23 -0400, Theodore Ts'o wrote:
> On-disk format definition for group descriptor checksums
> 
> - EXT4_FEATURE_RO_COMPAT_GDT_CSUM (0x0010?) - store a crc16 checksum in
>   the group descriptor (s_uuid[16] | __u32 group | ext3_group_desc
>   (excluding gd_checksum itself)).  This allows the kernel to more safely
>   manage UNINIT groups.
> 
> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Looks good to me.

> Index: e2fsprogs/lib/ext2fs/ext2_fs.h
> ===================================================================
> --- e2fsprogs.orig/lib/ext2fs/ext2_fs.h	2006-10-18 02:20:35.000000000 -0400
> +++ e2fsprogs/lib/ext2fs/ext2_fs.h	2006-10-18 02:20:41.000000000 -0400
> @@ -144,7 +144,9 @@
>  	__u16	bg_free_inodes_count;	/* Free inodes count */
>  	__u16	bg_used_dirs_count;	/* Directories count */
>  	__u16	bg_flags;
> -	__u32	bg_reserved[3];
> +	__u32	bg_reserved[2];
> +	__u16	bg_itable_unused;	/* Unused inodes count */
> +	__u16	bg_checksum;		/* crc16(s_uuid+grouo_num+group_desc)*/
>  };
>  
>  struct ext4_group_desc
> @@ -601,6 +603,7 @@
>  #define EXT2_FEATURE_RO_COMPAT_LARGE_FILE	0x0002
>  /* #define EXT2_FEATURE_RO_COMPAT_BTREE_DIR	0x0004 not used */
>  #define EXT4_FEATURE_RO_COMPAT_HUGE_FILE	0x0008
> +#define EXT4_FEATURE_RO_COMPAT_GDT_CSUM		0x0010
>  
>  #define EXT2_FEATURE_INCOMPAT_COMPRESSION	0x0001
>  #define EXT2_FEATURE_INCOMPAT_FILETYPE		0x0002

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.

-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
[prev in list] [next in list] [prev in thread] [next in thread]