[Devel] [PATCH] Fix Issue: When VirtIO Backend providing VIRTIO_BLK_F_MQ feature, The file system of the front-end OS fails to be mounted.

[Andrey Zhadchenko]

Hi

Thank you for the patch.
vhost-blk didn't spark enough interest to be reviewed and merged into 
the upstream and the code is not present here.
I have forwarded your patch to relevant openvz kernel mailing list.

On 5/17/24 07:34, Lynch wrote:
> ---
>   drivers/vhost/blk.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/vhost/blk.c b/drivers/vhost/blk.c
> index 44fbf253e773..0e946d9dfc33 100644
> --- a/drivers/vhost/blk.c
> +++ b/drivers/vhost/blk.c
> @@ -251,6 +251,7 @@ static int vhost_blk_bio_make(struct vhost_blk_req *req,
>   	struct page **pages, *page;
>   	struct bio *bio = NULL;
>   	int bio_nr = 0;
> +	sector_t sector_tmp;
>   
>   	if (unlikely(req->bi_opf == REQ_OP_FLUSH))
>   		return vhost_blk_bio_make_simple(req, bdev);
> @@ -270,6 +271,7 @@ static int vhost_blk_bio_make(struct vhost_blk_req *req,
>   		req->bio = req->inline_bio;
>   	}
>   
> +	sector_tmp = req->sector;
>   	req->iov_nr = 0;
>   	for (i = 0; i < iov_nr; i++) {
>   		int pages_nr = iov_num_pages(&iov[i]);
> @@ -302,7 +304,7 @@ static int vhost_blk_bio_make(struct vhost_blk_req *req,
>   				bio = bio_alloc(GFP_KERNEL, pages_nr_total);
>   				if (!bio)
>   					goto fail;
> -				bio->bi_iter.bi_sector  = req->sector;
> +				bio->bi_iter.bi_sector  = sector_tmp;
>   				bio_set_dev(bio, bdev);
>   				bio->bi_private = req;
>   				bio->bi_end_io  = vhost_blk_req_done;
> @@ -314,7 +316,7 @@ static int vhost_blk_bio_make(struct vhost_blk_req *req,
>   			iov_len		-= len;
>   
>   			pos = (iov_base & VHOST_BLK_SECTOR_MASK) + iov_len;
> -			req->sector += pos >> VHOST_BLK_SECTOR_BITS;
> +			sector_tmp += pos >> VHOST_BLK_SECTOR_BITS;
>   		}
>   
>   		pages += pages_nr;