Re: [PATCH 9/9] Amiga SmartFileSystem

[Matthew Wilcox <matthew@wil.cx>]

On Mon, Feb 09, 2009 at 09:57:21AM +0300, Pavel Fedin wrote:
> +struct fsBlockHeader {
> +       u32 id;                 /* 4 character id string of this block */
> +       u32 checksum;           /* The checksum */
> +       u32 ownblock;           /* The blocknumber of the block this
> block is stored at */
> +};

This (and other) on-disc structs can be annotated so that automated
tools like sparse can tell you if you've omitted an endian conversion
somewhere.  You can see examples of this in ext2:

struct ext2_group_desc
{
        __le32  bg_block_bitmap;                /* Blocks bitmap block */
        __le32  bg_inode_bitmap;                /* Inodes bitmap block */
        __le32  bg_inode_table;         /* Inodes table block */
        __le16  bg_free_blocks_count;   /* Free blocks count */
        __le16  bg_free_inodes_count;   /* Free inodes count */
        __le16  bg_used_dirs_count;     /* Directories count */
        __le16  bg_pad;
        __le32  bg_reserved[3];
};

Obviously, you'd want to use __be32 instead of __le32, but the principle
is there.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."