|author||ZiyangZhang <ZiyangZhang@linux.alibaba.com>||2022-07-28 20:39:15 +0800|
|committer||Jens Axboe <email@example.com>||2022-08-02 21:13:40 -0600|
ublk_cmd.h: add one new ublk command: UBLK_IO_NEED_GET_DATA
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. Reviewed-by: Ming Lei <firstname.lastname@example.org> Signed-off-by: ZiyangZhang <ZiyangZhang@linux.alibaba.com> Link: https://lore.kernel.org/r/c8a64b6b51c78340da7daa9e1054608695e79619.1659011443.git.ZiyangZhang@linux.alibaba.com Signed-off-by: Jens Axboe <email@example.com>
1 files changed, 18 insertions, 0 deletions
diff --git a/include/uapi/linux/ublk_cmd.h b/include/uapi/linux/ublk_cmd.h
index 57d86d0e8c5b..677edaab2b66 100644
@@ -30,12 +30,21 @@
* 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
@@ -56,6 +65,15 @@
#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