Re: [PATCH 3/5] xfs: compute dquot checksum after resetting dd_lsn in repair

["Darrick J. Wong" <djwong@kernel.org>]

On Thu, Sep 03, 2026 at 07:35:17AM +0200, Christoph Hellwig wrote:
> On Wed, Sep 02, 2026 at 08:37:03AM -0700, Darrick J. Wong wrote:
> > On Wed, Sep 02, 2026 at 09:23:41AM +0200, Christoph Hellwig wrote:
> > > On Tue, Sep 01, 2026 at 10:49:16PM -0700, Darrick J. Wong wrote:
> > > > From: Darrick J. Wong <djwong@kernel.org>
> > > > 
> > > > LOLLM complains that xrep_quota_block updates dd_lsn after calculating
> > > > the crc of the ondisk dquot.  That's clearly broken, so fix that.
> > > 
> > > Yeah:
> > > 
> > > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > > 
> > > Also why do we set the lsn to 0, shouldn't that contain a valid value
> > > (probably the current LSN, but I'd have to look deeper at what this
> > > does in detail)
> > 
> > Hmm.  When I wrote this dquot repair code I was mirroring what
> > xfs_qm_init_dquot_blk does (memsets the new dquot buffer to zeroes,
> > doesn't explicitly touch dd_lsn).
> > 
> > It probably ought to be set to the current LSN but we don't really have
> > a dquot log item for determining that, and assigning 0 here means that
> > any subsequent logged dquot item will always be recovered into the
> > ondisk dquot that xrep_quota_block writes.
> 
> Can we capture this for the future in comments somewhere?

Will add that and repost.

--D