Re: [PATCH] virtio-blk: Fix zone append sector reporting in batched completion

[Christoph Hellwig]

On Wed, Oct 28, 2026 at 10:27:08AM +0800, shao.mingyin@xxxxxxxxxx wrote:
> I looked into adding blktests coverage, and there is a structural
> problem. blktests cannot issue REQ_OP_ZONE_APPEND from userspace: fio's
> --zone_append goes through the io_uring_cmd NVMe passthrough path, so it
> never reaches the driver's zone-append completion, and zbdioctl has no
> append operation. blktests has no zone-append test today for the same
> reason.

Right.

> That does not fit blktests, which is a block-layer test suite driven
> from userspace. Two options as I see it:
> 
>   1. an XFS reproducer (e.g. xfstests) - the one that actually
>      exercises the append completion path, or
>   2. a blktests zbd test that covers a zoned virtio-blk with poll
>      queues, which would not reach the append part itself.
> 
> I am happy to write either, or to leave it if you think the coverage
> is not worth the churn. Which do you prefer?

We do have some blktests test that use a file system in the zbd
category (zbd/009, zbd/010, zbd/014) so I think we could do this in
blktests.  I.e. do a blktest that tests zoned polled I/O if we're
on a zoned device that support polling.