Re: [PATCH] xfs: fix XFS_ERRTAG_FORCE_ZERO_RANGE for zoned file system

[Christoph Hellwig <hch@lst.de>]

On Wed, Dec 10, 2025 at 10:36:55AM -0500, Brian Foster wrote:
> Is there a reason in particular for testing this with the zone mode?
> It's just a DEBUG thing for the zeroing mechanism. Why not just filter
> out the is_zoned_inode() case at the injection site?

Because I also want to be able to test the zeroing code for zoned
file systems, especially given zeroing is a bit of painful area
for out of place write file systems like zoned XFS.

> I suppose you could argue there is a point if we have separate zoned
> mode iomap callbacks and whatnot, but I agree the factoring here is a
> little unfortunate. I wonder if it would be nicer if we could set a flag
> or something on an ac and toggle the zone mode off that, but on a quick
> look I don't see a flag field in the zone ctx.

I don't really follow what you mean here.

> Hmm.. I wonder if we could still do something more clever where the zone
> mode has its own injection site to bump the res, and then the lower
> level logic just checks whether the reservation is sufficient for a full
> zero..? I'm not totally sure if that's ultimately cleaner, but maybe
> worth a thought..

We could have a different site for that injection, but we'd still need
to move the current one or at least make it conditional so that it
can't trigger for zoned mode.  I doubt that's less ugly than this
version.