Re: [PATCH v10 2/3] ublk: move check for empty address field on command submission

[Ming Lei]

Hi Andreas,

On Thu, Aug 03, 2023 at 04:07:00PM +0200, Andreas Hindborg (Samsung) wrote:
> From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
> 
> In preparation for zoned storage support, move the check for empty `addr`
> field into the command handler case statement. Note that the check makes no
> sense for `UBLK_IO_NEED_GET_DATA` because the `addr` field must always be
> set for this command.
> 
> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx>
> ---
>  drivers/block/ublk_drv.c | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index db3523e281a6..5a1ee17636ac 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -1419,11 +1419,6 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>  			^ (_IOC_NR(cmd_op) == UBLK_IO_NEED_GET_DATA))
>  		goto out;
>  
> -	if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
> -		ret = -EINVAL;
> -		goto out;
> -	}
> -
>  	ret = ublk_check_cmd_op(cmd_op);
>  	if (ret)
>  		goto out;
> @@ -1452,6 +1447,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>  				goto out;
>  		}
>  
> +		/* User copy requires addr to be unset */
> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +

Given you have to post v11 for fixing build issue, please convert the
above two 'if' into one 'if else':

		if (!ublk_support_user_copy(ubq)) {
			/*
			 * FETCH_RQ has to provide IO buffer if NEED GET
			 * DATA is not enabled
			 */
			if (!ub_cmd->addr && !ublk_need_get_data(ubq))
				goto out;
		} else {
			if (ub_cmd->addr) {
				ret = -EINVAL;
				goto out;
			}
		}

>  		ublk_fill_io_cmd(io, cmd, ub_cmd->addr);
>  		ublk_mark_io_ready(ub, ubq);
>  		break;
> @@ -1470,6 +1471,13 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
>  						req_op(req) == REQ_OP_READ))
>  				goto out;
>  		}
> +
> +		/* User copy requires addr to be unset */
> +		if (ublk_support_user_copy(ubq) && ub_cmd->addr) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +

Same with above.

BTW, I have verified this patchset with ublk-zoned example in
libublk-rs:

https://github.com/ming1/libublk-rs/tree/zoned.v2

cargo run --example zoned -- add -1 10240
mkfs.btrfs -O zoned /dev/ublkb0
mount & git clone linux-kernel &umount

Hope V11 can be merged.


Thanks,
Ming