On Wed, Jul 2, 2025 at 12:04 AM Ming Lei <ming.lei@xxxxxxxxxx> wrote:
>
> Refactor ublk_commit_and_fetch() in the following way for removing
> parameter of `struct ublksrv_io_cmd *`:
>
> - return `struct request *` from ublk_fill_io_cmd(), so that we can
> use request reference reliably in this way cause both request and
> io_uring_cmd reference share same storage
>
> - move ublk_fill_io_cmd() before calling into ublk_commit_and_fetch(),
> so that ublk_fill_io_cmd() could be run with per-io lock held for
> supporting command batch.
>
> - pass ->zone_append_lba to ublk_commit_and_fetch() directly
>
> The main motivation is to reproduce ublk_commit_and_fetch() for fetching
> io command batch with multishot uring_cmd.
>
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
> drivers/block/ublk_drv.c | 43 ++++++++++++++++++++++++++--------------
> 1 file changed, 28 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
> index 2dc6962c804a..1780f9ce3a24 100644
> --- a/drivers/block/ublk_drv.c
> +++ b/drivers/block/ublk_drv.c
> @@ -1983,10 +1983,13 @@ static inline int ublk_check_cmd_op(u32 cmd_op)
> return 0;
> }
>
> -static inline void ublk_fill_io_cmd(struct ublk_io *io,
> - struct io_uring_cmd *cmd, unsigned long buf_addr,
> - int result)
> +/* Once we return, `io->req` can't be used any more */
> +static inline struct request *
> +ublk_fill_io_cmd(struct ublk_io *io, struct io_uring_cmd *cmd,
> + unsigned long buf_addr, int result)
> {
> + struct request *req = io->req;
> +
> io->cmd = cmd;
> io->flags |= UBLK_IO_FLAG_ACTIVE;
> io->addr = buf_addr;
> @@ -1994,6 +1997,8 @@ static inline void ublk_fill_io_cmd(struct ublk_io *io,
>
> /* now this cmd slot is owned by ublk driver */
> io->flags &= ~UBLK_IO_FLAG_OWNED_BY_SRV;
> +
> + return req;
This is nice symmetry with __ublk_prep_compl_io_cmd().
Reviewed-by: Caleb Sander Mateos <csander@xxxxxxxxxxxxxxx>
> }
>
> static inline void ublk_prep_cancel(struct io_uring_cmd *cmd,
> @@ -2159,10 +2164,8 @@ static int ublk_fetch(struct io_uring_cmd *cmd, struct ublk_queue *ubq,
> return ret;
> }
>
> -static int ublk_commit_and_fetch(const struct ublk_queue *ubq,
> - struct ublk_io *io, struct io_uring_cmd *cmd,
> - const struct ublksrv_io_cmd *ub_cmd,
> - unsigned int issue_flags)
> +static int ublk_check_commit_and_fetch(const struct ublk_queue *ubq,
> + struct ublk_io *io, __u64 buf_addr)
> {
> struct request *req = io->req;
>
> @@ -2171,10 +2174,10 @@ static int ublk_commit_and_fetch(const struct ublk_queue *ubq,
> * COMMIT_AND_FETCH_REQ has to provide IO buffer if
> * NEED GET DATA is not enabled or it is Read IO.
> */
> - if (!ub_cmd->addr && (!ublk_need_get_data(ubq) ||
> + if (!buf_addr && (!ublk_need_get_data(ubq) ||
> req_op(req) == REQ_OP_READ))
> return -EINVAL;
> - } else if (req_op(req) != REQ_OP_ZONE_APPEND && ub_cmd->addr) {
> + } else if (req_op(req) != REQ_OP_ZONE_APPEND && buf_addr) {
> /*
> * User copy requires addr to be unset when command is
> * not zone append
> @@ -2182,6 +2185,14 @@ static int ublk_commit_and_fetch(const struct ublk_queue *ubq,
> return -EINVAL;
> }
>
> + return 0;
> +}
> +
> +static int ublk_commit_and_fetch(const struct ublk_queue *ubq,
> + struct ublk_io *io, struct io_uring_cmd *cmd,
> + struct request *req, unsigned int issue_flags,
> + __u64 zone_append_lba)
> +{
> if (ublk_support_auto_buf_reg(ubq)) {
> int ret;
>
> @@ -2207,10 +2218,8 @@ static int ublk_commit_and_fetch(const struct ublk_queue *ubq,
> return ret;
> }
>
> - ublk_fill_io_cmd(io, cmd, ub_cmd->addr, ub_cmd->result);
> -
> if (req_op(req) == REQ_OP_ZONE_APPEND)
> - req->__sector = ub_cmd->zone_append_lba;
> + req->__sector = zone_append_lba;
>
> if (ublk_need_req_ref(ubq))
> ublk_sub_req_ref(io, req);
> @@ -2316,7 +2325,12 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
> return ublk_daemon_register_io_buf(cmd, ubq, io, ub_cmd->addr,
> issue_flags);
> case UBLK_IO_COMMIT_AND_FETCH_REQ:
> - ret = ublk_commit_and_fetch(ubq, io, cmd, ub_cmd, issue_flags);
> + ret = ublk_check_commit_and_fetch(ubq, io, ub_cmd->addr);
> + if (ret)
> + goto out;
> + req = ublk_fill_io_cmd(io, cmd, ub_cmd->addr, ub_cmd->result);
> + ret = ublk_commit_and_fetch(ubq, io, cmd, req, issue_flags,
> + ub_cmd->zone_append_lba);
> if (ret)
> goto out;
> break;
> @@ -2326,8 +2340,7 @@ static int __ublk_ch_uring_cmd(struct io_uring_cmd *cmd,
> * uring_cmd active first and prepare for handling new requeued
> * request
> */
> - req = io->req;
> - ublk_fill_io_cmd(io, cmd, ub_cmd->addr, 0);
> + req = ublk_fill_io_cmd(io, cmd, ub_cmd->addr, 0);
> if (likely(ublk_get_data(ubq, io, req))) {
> __ublk_prep_compl_io_cmd(io, req);
> return UBLK_IO_RES_OK;
> --
> 2.47.0
>
