[PATCH V3 04/16] io_uring: support OP_SEND_ZC/OP_RECV for fused slave request

[Ming Lei <ming.lei@redhat.com>]

Start to allow fused slave request to support OP_SEND_ZC/OP_RECV, and
the buffer can be retrieved from master request.

Once the slave request is completed, the master buffer will be returned
back.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 io_uring/net.c   | 30 ++++++++++++++++++++++++++++--
 io_uring/opdef.c |  3 +++
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index b7f190ca528e..78fb2d08ecd0 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -16,6 +16,7 @@
 #include "net.h"
 #include "notif.h"
 #include "rsrc.h"
+#include "fused_cmd.h"
 
 #if defined(CONFIG_NET)
 struct io_shutdown {
@@ -68,6 +69,13 @@ struct io_sr_msg {
 	struct io_kiocb 		*notif;
 };
 
+#define user_ptr_to_u64(x) (		\
+{					\
+	typecheck(void __user *, (x));		\
+	(u64)(unsigned long)(x);	\
+}					\
+)
+
 static inline bool io_check_multishot(struct io_kiocb *req,
 				      unsigned int issue_flags)
 {
@@ -378,7 +386,11 @@ int io_send(struct io_kiocb *req, unsigned int issue_flags)
 	if (unlikely(!sock))
 		return -ENOTSOCK;
 
-	ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &msg.msg_iter);
+	if (!(req->flags & REQ_F_FUSED_SLAVE))
+		ret = import_ubuf(ITER_SOURCE, sr->buf, sr->len, &msg.msg_iter);
+	else
+		ret = io_import_kbuf_for_slave(user_ptr_to_u64(sr->buf),
+				sr->len, ITER_SOURCE, &msg.msg_iter, req);
 	if (unlikely(ret))
 		return ret;
 
@@ -869,7 +881,11 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags)
 		sr->buf = buf;
 	}
 
-	ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
+	if (!(req->flags & REQ_F_FUSED_SLAVE))
+		ret = import_ubuf(ITER_DEST, sr->buf, len, &msg.msg_iter);
+	else
+		ret = io_import_kbuf_for_slave(user_ptr_to_u64(sr->buf),
+				sr->len, ITER_DEST, &msg.msg_iter, req);
 	if (unlikely(ret))
 		goto out_free;
 
@@ -983,6 +999,9 @@ int io_send_zc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	if (zc->flags & IORING_RECVSEND_FIXED_BUF) {
 		unsigned idx = READ_ONCE(sqe->buf_index);
 
+		if (req->flags & REQ_F_FUSED_SLAVE)
+			return -EINVAL;
+
 		if (unlikely(idx >= ctx->nr_user_bufs))
 			return -EFAULT;
 		idx = array_index_nospec(idx, ctx->nr_user_bufs);
@@ -1119,8 +1138,15 @@ int io_send_zc(struct io_kiocb *req, unsigned int issue_flags)
 		if (unlikely(ret))
 			return ret;
 		msg.sg_from_iter = io_sg_from_iter;
+	} else if (req->flags & REQ_F_FUSED_SLAVE) {
+		ret = io_import_kbuf_for_slave(user_ptr_to_u64(zc->buf),
+				zc->len, ITER_SOURCE, &msg.msg_iter, req);
+		if (unlikely(ret))
+			return ret;
+		msg.sg_from_iter = io_sg_from_iter;
 	} else {
 		io_notif_set_extended(zc->notif);
+
 		ret = import_ubuf(ITER_SOURCE, zc->buf, zc->len, &msg.msg_iter);
 		if (unlikely(ret))
 			return ret;
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index f044629e5475..0a9d39a9db16 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -271,6 +271,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.audit_skip		= 1,
 		.ioprio			= 1,
 		.manual_alloc		= 1,
+		.fused_slave		= 1,
 #if defined(CONFIG_NET)
 		.prep			= io_sendmsg_prep,
 		.issue			= io_send,
@@ -285,6 +286,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.buffer_select		= 1,
 		.audit_skip		= 1,
 		.ioprio			= 1,
+		.fused_slave		= 1,
 #if defined(CONFIG_NET)
 		.prep			= io_recvmsg_prep,
 		.issue			= io_recv,
@@ -411,6 +413,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.audit_skip		= 1,
 		.ioprio			= 1,
 		.manual_alloc		= 1,
+		.fused_slave		= 1,
 #if defined(CONFIG_NET)
 		.prep			= io_send_zc_prep,
 		.issue			= io_send_zc,
-- 
2.39.2