Re: [PATCH 3/5] generic/746: skip on zoned btrfs

[Johannes Thumshirn <johannes.thumshirn@wdc.com>]

On Mon, Jul 20, 2026 at 10:37:38AM -0700, Christoph Hellwig wrote:
> On Mon, Jul 20, 2026 at 01:18:47PM +0200, Johannes Thumshirn wrote:
> > The test relies on loop device discards punching holes in the backing
> > image file (holes are then detected via fiemap on the backing file).
> > Zoned btrfs does not support fallocate/punch hole, so fstrim on the
> > loop device cannot free space in the backing file and the test cannot
> > work.
> > 
> > Skip the test on zoned devices, but only for btrfs so that other
> > filesystems (e.g. zoned XFS/f2fs) can still run it.
> 
> This should use feature detection and not hard code file systems.

I didn't find anything for that. Only using _require_xfs_io_command
"fpunch", but the test is not using ot so it felt wrong. 

> 
> I'm also a bit surprised that zoned btrfs doesn't support hole
> punches.  Unlike classic unwritten extents there is nothing in a
> zone model preventing them from working.  Did you try just enabling
> hole punches in btrfs?
>

It is not the zoned device model that prevents us but a desciccion we
did in zoned BTRFS when doing the initial support for it. I can look
into hole punching but I got a lot of other more urgent fires to put out
and features people are waiting for first.