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

From: Andreas Hindborg (Samsung)
Date: Fri Aug 04 2023 - 06:12:32 EST



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