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

[Andreas Hindborg (Samsung)]

Ming Lei <tom.leiming@xxxxxxxxx> writes:

> 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;
> 			}
> 		}

Alright. I was debating with myself one over the other 😅

>
>>  		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

Thanks!

BR Andreas