Re: [PATCH 13/13] xfs: add CRC checks for quota blocks

["Josef 'Jeff' Sipek" <jeffpc@josefsipek.net>]

On Tue, Feb 10, 2009 at 03:22:54PM -0500, Christoph Hellwig wrote:
> Use the reserved space in struct xfs_dqblk to store a UUID and a crc
> for the quota blocks.
> 
> I'm pondering if we should just move the crc check into xfs_qm_dqcheck
> where all the other validity checks are located.
> 
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Index: xfs/fs/xfs/xfs_quota.h
> ===================================================================
> --- xfs.orig/fs/xfs/xfs_quota.h	2009-02-09 08:47:34.234069111 +0100
> +++ xfs/fs/xfs/xfs_quota.h	2009-02-10 20:15:36.874947481 +0100
> @@ -77,7 +77,13 @@ typedef struct	xfs_disk_dquot {
>   */
>  typedef struct xfs_dqblk {
>  	xfs_disk_dquot_t  dd_diskdq;	/* portion that lives incore as well */
> -	char		  dd_fill[32];	/* filling for posterity */
> +	char		  dd_fill[12];	/* filling for posterity */
> +
> +	/*
> +	 * These two are only present one filesystems with the CRC bits set.
> +	 */
> +	__be32		  dd_crc;	/* checksum */
> +	uuid_t		  dd_uuid;	/* location information */
>  } xfs_dqblk_t;

Again, why put the crc/uuid at the end?

> Index: xfs/fs/xfs/quota/xfs_dquot.c
> ===================================================================
> --- xfs.orig/fs/xfs/quota/xfs_dquot.c	2009-02-10 19:55:01.982070089 +0100
> +++ xfs/fs/xfs/quota/xfs_dquot.c	2009-02-10 20:23:25.618944664 +0100
> @@ -368,6 +369,40 @@ xfs_qm_adjust_dqtimers(
...
> +STATIC int
> +xfs_dquot_verify_crc(
> +	struct xfs_mount	*mp,
> +	struct xfs_buf		*bp)
> +{
> +	struct xfs_dqblk	*d = (struct xfs_dqblk *)XFS_BUF_PTR(bp);
> +	int			i;
> +
> +	for (i = 0; i < XFS_QM_DQPERBLK(mp); i++, d++) {
> +		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
> +				 offsetof(struct xfs_dqblk, dd_crc))) {
> +//		    !uuid_equal(&agfl->agfl_uuid, &mp->m_sb.sb_uuid) ||

Dead code?

Josef 'Jeff' Sipek.

-- 
FORTUNE PROVIDES QUESTIONS FOR THE GREAT ANSWERS: #19
A:      To be or not to be.
Q:      What is the square root of 4b^2?

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs