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

Christoph Hellwig
2009-02-13T20:11:03Z

On Thu, Feb 12, 2009 at 01:41:28AM -0500, Josef 'Jeff' Sipek wrote:
> > 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?

So that we can add additional infos either to xfs_disk_dquot_t
(preserved in-core) or xfs_dqblk_t (purly on-disk).

> > + 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?

Sorry, sent out a too early version. The final patch actually verifies
the uuid and the correct location in the quota file.