Re: [PATCH] mkfs.xfs fix sunit size on 512e and 4kN disks.

[Christoph Hellwig <hch@infradead.org>]

On Mon, Sep 29, 2025 at 10:59:24AM +0200, lukas@herbolt.com wrote:
> > You Before/after also contain changes for metadir/zoned, looks like you
> > upgraded to a new xfsprogs for your patch, but not the baseline.
> > 
> Yeah it was fedora rawhide, 6.12, did not notice the metadir/zoned.

Np.  I just started at it to see what you changed.

> > I don't think just picking the data stripe unit is correct here, given
> > that the log can also be external and on a separate device.  Instead
> > we'll need to duplicate the calculation based on ft.log, preferably by
> > factoring it into a helper.
> Hmmm, aren't all the <data|rt|log>.sunit" set by blkid_get_topology()?

Yes.

> So as log is internal lsunit should be equal to dsunit and it can only
> differ if the log is external?

Yes.

> My understanding was the LSU check is there mostly if cli->lsu is set.
> Actually if that's assumption is correct it can be done just like this.

That might be a better idea, and should be done in a prep patch.