Add one new ublk command: UBLK_IO_NEED_GET_DATA. It is prepared for a new feature designed for a user application who wants to allocate IO buffer and set IO buffer address only after it receives an IO request from ublksrv. Signed-off-by: ZiyangZhang <ZiyangZhang@xxxxxxxxxxxxxxxxx> --- include/uapi/linux/ublk_cmd.h | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h index ca33092354ab..c986b4971423 100644 --- a/include/uapi/linux/ublk_cmd.h +++ b/include/uapi/linux/ublk_cmd.h @@ -28,12 +28,21 @@ * this IO request, request's handling result is committed to ublk * driver, meantime FETCH_REQ is piggyback, and FETCH_REQ has to be * handled before completing io request. + * + * NEED_GET_DATA: only used for write requests to set io addr and copy data + * When NEED_GET_DATA is set, ublksrv has to issue UBLK_IO_NEED_GET_DATA + * command after ublk driver returns UBLK_IO_RES_NEED_GET_DATA. + * + * It is only used if ublksrv set UBLK_F_NEED_GET_DATA flag + * while starting a ublk device. */ #define UBLK_IO_FETCH_REQ 0x20 #define UBLK_IO_COMMIT_AND_FETCH_REQ 0x21 +#define UBLK_IO_NEED_GET_DATA 0x22 /* only ABORT means that no re-fetch */ #define UBLK_IO_RES_OK 0 +#define UBLK_IO_RES_NEED_GET_DATA 1 #define UBLK_IO_RES_ABORT (-ENODEV) #define UBLKSRV_CMD_BUF_OFFSET 0 @@ -54,6 +63,15 @@ */ #define UBLK_F_URING_CMD_COMP_IN_TASK (1ULL << 1) +/* + * User should issue io cmd again for write requests to + * set io buffer address and copy data from bio vectors + * to the userspace io buffer. + * + * In this mode, task_work is not used. + */ +#define UBLK_F_NEED_GET_DATA (1UL << 2) + /* device state */ #define UBLK_S_DEV_DEAD 0 #define UBLK_S_DEV_LIVE 1 -- 2.34.1
