Re: [PATCH 06/14] xfs: fix xfs_rename_space_res for non-pptr filesystems

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

On Mon, Sep 21, 2026 at 10:20:01PM -0700, Christoph Hellwig wrote:
> On Sun, Sep 20, 2026 at 11:16:32PM -0700, Darrick J. Wong wrote:
> > From: Darrick J. Wong <djwong@kernel.org>
> > 
> > We don't need to reserve space for a parent pointer update for an
> > existing target if parent pointers are disabled.  Fix this regression
> > (which LOLLM noticed) so that rename reservations go back to what they
> > were before parent pointers.
> > 
> > Cc: <stable@vger.kernel.org> # v6.10
> > Fixes: 5a8338c88284df ("xfs: Add parent pointers to rename")
> 
> This just relaxed a reservation.  I don't think this is a stable/7.3
> candidate and probably should not have a fixes tag that causes folks
> to backport it.

Yes it relaxes a reservation, but only for non-parent pointers
filesystems running on newer kernels.  IOWs, it reduces the reservation
back to what it was before parent pointers, so it actually has some
performance implications for old filesystems.

OTOH nobody's complained about the dip in performance so <shrug> I don't
really care that much either way.

> Otherwise looks good:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks!

--D