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

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

[shao.mingyin]

From: Shao Mingyin <shao.mingyin@zte.com.cn>

For zone append, the block layer copies req->__sector back into the
bio in blk_zone_append_update_request_bio(), so the driver must update
req->__sector with the sector reported by the device.
virtblk_request_done() does that, but the batched completion path used
by virtblk_poll() only unmaps and cleans up the requests before calling
blk_mq_end_request_batch().

A zone append completed through polling therefore keeps the sector that
was assigned at submission time, and the file system or application sees
the wrong LBA for the written data.

Move the sector update into a helper and call it from both completion
paths.

Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn>
---
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index c8bfbf8435ac..cc29b8238a4d 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -331,18 +331,25 @@ static inline u8 virtblk_vbr_status(struct virtblk_req *vbr)
 	return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1);
 }

+static inline void virtblk_update_zone_append_sector(struct request *req,
+						     struct virtblk_req *vbr)
+{
+	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
+
+	if (req_op(req) == REQ_OP_ZONE_APPEND)
+		req->__sector = virtio64_to_cpu(vblk->vdev,
+						vbr->in_hdr.zone_append.sector);
+}
+
 static inline void virtblk_request_done(struct request *req)
 {
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
 	blk_status_t status = virtblk_result(virtblk_vbr_status(vbr));
-	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;

 	virtblk_unmap_data(req, vbr);
 	virtblk_cleanup_cmd(req);

-	if (req_op(req) == REQ_OP_ZONE_APPEND)
-		req->__sector = virtio64_to_cpu(vblk->vdev,
-						vbr->in_hdr.zone_append.sector);
+	virtblk_update_zone_append_sector(req, vbr);

 	blk_mq_end_request(req, status);
 }
@@ -1196,8 +1203,11 @@ static void virtblk_complete_batch(struct io_comp_batch *iob)
 	struct request *req;

 	rq_list_for_each(&iob->req_list, req) {
-		virtblk_unmap_data(req, blk_mq_rq_to_pdu(req));
+		struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
+
+		virtblk_unmap_data(req, vbr);
 		virtblk_cleanup_cmd(req);
+		virtblk_update_zone_append_sector(req, vbr);
 	}
 	blk_mq_end_request_batch(iob);
 }

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

[Christoph Hellwig]

On Mon, Oct 26, 2026 at 07:55:19PM +0800, shao.mingyin@zte.com.cn wrote:
> From: Shao Mingyin <shao.mingyin@zte.com.cn>
> 
> For zone append, the block layer copies req->__sector back into the
> bio in blk_zone_append_update_request_bio(), so the driver must update
> req->__sector with the sector reported by the device.
> virtblk_request_done() does that, but the batched completion path used
> by virtblk_poll() only unmaps and cleans up the requests before calling
> blk_mq_end_request_batch().
> 
> A zone append completed through polling therefore keeps the sector that
> was assigned at submission time, and the file system or application sees
> the wrong LBA for the written data.
> 
> Move the sector update into a helper and call it from both completion
> paths.

Looks good:

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

Can you add something to blktests to exercises this?

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

[Stefan Hajnoczi]

On Mon, Oct 26, 2026 at 07:55:19PM +0800, shao.mingyin@zte.com.cn wrote:
> From: Shao Mingyin <shao.mingyin@zte.com.cn>
> 
> For zone append, the block layer copies req->__sector back into the
> bio in blk_zone_append_update_request_bio(), so the driver must update
> req->__sector with the sector reported by the device.
> virtblk_request_done() does that, but the batched completion path used
> by virtblk_poll() only unmaps and cleans up the requests before calling
> blk_mq_end_request_batch().
> 
> A zone append completed through polling therefore keeps the sector that
> was assigned at submission time, and the file system or application sees
> the wrong LBA for the written data.
> 
> Move the sector update into a helper and call it from both completion
> paths.
> 
> Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
> Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn>

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

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

[Michael S. Tsirkin]

On Mon, Oct 26, 2026 at 07:55:19PM +0800, shao.mingyin@zte.com.cn wrote:
> From: Shao Mingyin <shao.mingyin@zte.com.cn>
> 
> For zone append, the block layer copies req->__sector back into the
> bio in blk_zone_append_update_request_bio(), so the driver must update
> req->__sector with the sector reported by the device.
> virtblk_request_done() does that, but the batched completion path used
> by virtblk_poll() only unmaps and cleans up the requests before calling
> blk_mq_end_request_batch().
> 
> A zone append completed through polling therefore keeps the sector that
> was assigned at submission time, and the file system or application sees
> the wrong LBA for the written data.
> 
> Move the sector update into a helper and call it from both completion
> paths.
> 
> Fixes: 95bfec41bd3d ("virtio-blk: add support for zoned block devices")
> Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
> diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
> index c8bfbf8435ac..cc29b8238a4d 100644
> --- a/drivers/block/virtio_blk.c
> +++ b/drivers/block/virtio_blk.c
> @@ -331,18 +331,25 @@ static inline u8 virtblk_vbr_status(struct virtblk_req *vbr)
>  	return *((u8 *)&vbr->in_hdr + vbr->in_hdr_len - 1);
>  }
> 
> +static inline void virtblk_update_zone_append_sector(struct request *req,
> +						     struct virtblk_req *vbr)
> +{
> +	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
> +
> +	if (req_op(req) == REQ_OP_ZONE_APPEND)
> +		req->__sector = virtio64_to_cpu(vblk->vdev,
> +						vbr->in_hdr.zone_append.sector);
> +}
> +
>  static inline void virtblk_request_done(struct request *req)
>  {
>  	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
>  	blk_status_t status = virtblk_result(virtblk_vbr_status(vbr));
> -	struct virtio_blk *vblk = req->mq_hctx->queue->queuedata;
> 
>  	virtblk_unmap_data(req, vbr);
>  	virtblk_cleanup_cmd(req);
> 
> -	if (req_op(req) == REQ_OP_ZONE_APPEND)
> -		req->__sector = virtio64_to_cpu(vblk->vdev,
> -						vbr->in_hdr.zone_append.sector);
> +	virtblk_update_zone_append_sector(req, vbr);
> 
>  	blk_mq_end_request(req, status);
>  }
> @@ -1196,8 +1203,11 @@ static void virtblk_complete_batch(struct io_comp_batch *iob)
>  	struct request *req;
> 
>  	rq_list_for_each(&iob->req_list, req) {
> -		virtblk_unmap_data(req, blk_mq_rq_to_pdu(req));
> +		struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
> +
> +		virtblk_unmap_data(req, vbr);
>  		virtblk_cleanup_cmd(req);
> +		virtblk_update_zone_append_sector(req, vbr);
>  	}
>  	blk_mq_end_request_batch(iob);
>  }