Re: [PATCH 09/12] xfs: break out of zoned reservation loop if signals are pending

[Christoph Hellwig <hch@infradead.org>]

On Thu, Sep 24, 2026 at 09:12:51PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> I noticed that if you run generic/476 for long enough on a zoned
> filesystem that it runs out of space in the zoned section, fsstress gets
> stuck in this loop trying to reserve space, failing, and kicking off the
> gc.

I guess this is not directly fixed here, right?

> The garbage collector in turn is continuously running (so we don't
> break out of the loop) but the process is no longer responsive to
> signals and can't be killed.
> 
> Fix this by backing out to userspace for any pending signal.  This
> should be safe because space reservation is usually the first step in
> any modification to a zoned file.
> 
> Cc: <hch@lst.de>
> Cc: <stable@vger.kernel.org> # v6.15
> Fixes: 0bb2193056b596 ("xfs: add support for zoned space reservations")
> Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
> ---
>  fs/xfs/xfs_zone_space_resv.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> 
> diff --git a/fs/xfs/xfs_zone_space_resv.c b/fs/xfs/xfs_zone_space_resv.c
> index 7aa3c74fb2e01a..8edc82025abbd5 100644
> --- a/fs/xfs/xfs_zone_space_resv.c
> +++ b/fs/xfs/xfs_zone_space_resv.c
> @@ -157,6 +157,11 @@ xfs_zoned_reserve_available(
>  		if (error != -ENOSPC)
>  			break;
>  
> +		if (signal_pending(current)) {
> +			error = -ERESTARTSYS;
> +			break;
> +		}

I don't think normal fs read/write semantics allow for -ERESTARTSYS
on arbitrary signals.  So this should probably be limited to
fatal_signal_pending().