[PATCH 1/3] io_uring/net: move io_sr_msg->retry_flags to io_sr_msg->flags

[Jens Axboe <axboe@kernel.dk>]

There's plenty of space left, we just have to cleanly separate the
UAPI flags and the internal ones. This avoids needing to init them for
request initialization, or clear them separately for request retries.

Add a mask for the UAPI flags so that a BUILD_BUG_ON() can be added if
there's ever any overlap. As of this commit, UAPI uses the bottom 5 bits
and the internal uses are the top two bits. This still leaves room for
an additional 8 UAPI flags.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/uapi/linux/io_uring.h |  9 +++++++++
 io_uring/net.c                | 29 ++++++++++++++++++-----------
 2 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index b8a0e70ee2fd..7c828fe944b1 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -399,6 +399,15 @@ enum io_uring_op {
 #define IORING_SEND_ZC_REPORT_USAGE	(1U << 3)
 #define IORING_RECVSEND_BUNDLE		(1U << 4)
 
+/*
+ * Not immediately useful for application, just a mask of all the exposed flags
+ */
+#define IORING_RECVSEND_FLAGS_ALL	(IORING_RECVSEND_POLL_FIRST |	\
+					 IORING_RECV_MULTISHOT |	\
+					 IORING_RECVSEND_FIXED_BUF |	\
+					 IORING_SEND_ZC_REPORT_USAGE |	\
+					 IORING_RECVSEND_BUNDLE)
+
 /*
  * cqe.res for IORING_CQE_F_NOTIF if
  * IORING_SEND_ZC_REPORT_USAGE was requested
diff --git a/io_uring/net.c b/io_uring/net.c
index 43a43522f406..328301dc9a43 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -75,15 +75,21 @@ struct io_sr_msg {
 	u16				flags;
 	/* initialised and used only by !msg send variants */
 	u16				buf_group;
-	unsigned short			retry_flags;
 	void __user			*msg_control;
 	/* used only for send zerocopy */
 	struct io_kiocb 		*notif;
 };
 
+/*
+ * Can't overlap with the send/sendmsg or recv/recvmsg flags defined in
+ * the UAPI. Start high and work down.
+ */
 enum sr_retry_flags {
-	IO_SR_MSG_RETRY		= 1,
-	IO_SR_MSG_PARTIAL_MAP	= 2,
+	IORING_RECV_RETRY	= (1U << 15),
+	IORING_RECV_PARTIAL_MAP	= (1U << 14),
+
+	IORING_RECV_RETRY_CLEAR	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP,
+	IORING_RECV_INTERNAL	= IORING_RECV_RETRY | IORING_RECV_PARTIAL_MAP,
 };
 
 /*
@@ -190,9 +196,12 @@ static inline void io_mshot_prep_retry(struct io_kiocb *req,
 {
 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 
+	/* internal and external flags must not overlap */
+	BUILD_BUG_ON(IORING_RECVSEND_FLAGS_ALL & IORING_RECV_INTERNAL);
+
 	req->flags &= ~REQ_F_BL_EMPTY;
 	sr->done_io = 0;
-	sr->retry_flags = 0;
+	sr->flags &= ~IORING_RECV_RETRY_CLEAR;
 	sr->len = 0; /* get from the provided buffer */
 }
 
@@ -402,7 +411,6 @@ int io_sendmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 
 	sr->done_io = 0;
-	sr->retry_flags = 0;
 	sr->len = READ_ONCE(sqe->len);
 	sr->flags = READ_ONCE(sqe->ioprio);
 	if (sr->flags & ~SENDMSG_FLAGS)
@@ -756,7 +764,6 @@ int io_recvmsg_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	struct io_sr_msg *sr = io_kiocb_to_cmd(req, struct io_sr_msg);
 
 	sr->done_io = 0;
-	sr->retry_flags = 0;
 
 	if (unlikely(sqe->file_index || sqe->addr2))
 		return -EINVAL;
@@ -828,7 +835,7 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
 
 		cflags |= io_put_kbufs(req, this_ret, io_bundle_nbufs(kmsg, this_ret),
 				      issue_flags);
-		if (sr->retry_flags & IO_SR_MSG_RETRY)
+		if (sr->flags & IORING_RECV_RETRY)
 			cflags = req->cqe.flags | (cflags & CQE_F_MASK);
 		/* bundle with no more immediate buffers, we're done */
 		if (req->flags & REQ_F_BL_EMPTY)
@@ -837,12 +844,13 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
 		 * If more is available AND it was a full transfer, retry and
 		 * append to this one
 		 */
-		if (!sr->retry_flags && kmsg->msg.msg_inq > 1 && this_ret > 0 &&
+		if (!(sr->flags & IORING_RECV_INTERNAL) &&
+		    kmsg->msg.msg_inq > 1 && this_ret > 0 &&
 		    !iov_iter_count(&kmsg->msg.msg_iter)) {
 			req->cqe.flags = cflags & ~CQE_F_MASK;
 			sr->len = kmsg->msg.msg_inq;
 			sr->done_io += this_ret;
-			sr->retry_flags |= IO_SR_MSG_RETRY;
+			sr->flags |= IORING_RECV_RETRY;
 			return false;
 		}
 	} else {
@@ -1088,7 +1096,7 @@ static int io_recv_buf_select(struct io_kiocb *req, struct io_async_msghdr *kmsg
 			req->flags |= REQ_F_NEED_CLEANUP;
 		}
 		if (arg.partial_map)
-			sr->retry_flags |= IO_SR_MSG_PARTIAL_MAP;
+			sr->flags |= IORING_RECV_PARTIAL_MAP;
 
 		/* special case 1 vec, can be a fast path */
 		if (ret == 1) {
@@ -1283,7 +1291,6 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	int ret;
 
 	zc->done_io = 0;
-	zc->retry_flags = 0;
 
 	if (unlikely(READ_ONCE(sqe->__pad2[0]) || READ_ONCE(sqe->addr3)))
 		return -EINVAL;
-- 
2.50.0