[PATCH 1/3] io_uring: add IOSQE_MULTI_CQES/REQ_F_MULTI_CQES for multishot requests

[Hao Xu <haoxu@linux.alibaba.com>]

Since we now have requests that may generate multiple cqes, we need a
new flag to mark them, so that we can maintain features like drain io
easily for them.

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
---
 fs/io_uring.c                 | 5 ++++-
 include/uapi/linux/io_uring.h | 3 +++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 81e5d156af1c..192463bb977a 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -102,7 +102,7 @@
 
 #define SQE_VALID_FLAGS	(IOSQE_FIXED_FILE|IOSQE_IO_DRAIN|IOSQE_IO_LINK|	\
 				IOSQE_IO_HARDLINK | IOSQE_ASYNC | \
-				IOSQE_BUFFER_SELECT)
+				IOSQE_BUFFER_SELECT | IOSQE_MULTI_CQES)
 
 struct io_uring {
 	u32 head ____cacheline_aligned_in_smp;
@@ -700,6 +700,7 @@ enum {
 	REQ_F_HARDLINK_BIT	= IOSQE_IO_HARDLINK_BIT,
 	REQ_F_FORCE_ASYNC_BIT	= IOSQE_ASYNC_BIT,
 	REQ_F_BUFFER_SELECT_BIT	= IOSQE_BUFFER_SELECT_BIT,
+	REQ_F_MULTI_CQES_BIT	= IOSQE_MULTI_CQES_BIT,
 
 	REQ_F_FAIL_LINK_BIT,
 	REQ_F_INFLIGHT_BIT,
@@ -766,6 +767,8 @@ enum {
 	REQ_F_ASYNC_WRITE	= BIT(REQ_F_ASYNC_WRITE_BIT),
 	/* regular file */
 	REQ_F_ISREG		= BIT(REQ_F_ISREG_BIT),
+	/* a request can generate multiple cqes */
+	REQ_F_MULTI_CQES	= BIT(REQ_F_MULTI_CQES_BIT),
 };
 
 struct async_poll {
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 5beaa6bbc6db..303ac8005572 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -70,6 +70,7 @@ enum {
 	IOSQE_IO_HARDLINK_BIT,
 	IOSQE_ASYNC_BIT,
 	IOSQE_BUFFER_SELECT_BIT,
+	IOSQE_MULTI_CQES_BIT,
 };
 
 /*
@@ -87,6 +88,8 @@ enum {
 #define IOSQE_ASYNC		(1U << IOSQE_ASYNC_BIT)
 /* select buffer from sqe->buf_group */
 #define IOSQE_BUFFER_SELECT	(1U << IOSQE_BUFFER_SELECT_BIT)
+/* may generate multiple cqes */
+#define IOSQE_MULTI_CQES	(1U << IOSQE_MULTI_CQES_BIT)
 
 /*
  * io_uring_setup() flags
-- 
1.8.3.1