[PATCH v2 1/3] io_uring/net: Avoid msghdr on op_connect/op_bind async data

Both IORING_OP_CONNECT and IORING_OP_BIND reuse the msghdr object just
to store the sockaddr.  Beyond allocating a much larger object than
needed, msghdr can also wrap an iovec, which will be recycled
unnecessarily.  This uses the sockaddr directly.

Signed-off-by: Gabriel Krisman Bertazi <[email protected]>

---
Since v1:
  - use sockaddr directly
---
 io_uring/net.c   | 30 ++++++++++++++----------------
 io_uring/opdef.c |  4 ++--
 2 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index cceb5c1409ca..7ff5975e118b 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1677,8 +1677,7 @@ void io_socket_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
 void io_connect_bpf_populate(struct io_uring_bpf_ctx *bctx, struct io_kiocb *req)
 {
 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
-	struct io_async_msghdr *iomsg = req->async_data;
-	struct sockaddr_storage *ss = &iomsg->addr;
+	struct sockaddr_storage *ss = req->async_data;
 
 	/*
 	 * move_addr_to_kernel() skips the copy for addr_len == 0, so
@@ -1772,7 +1771,7 @@ int io_socket(struct io_kiocb *req, unsigned int issue_flags)
 int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	struct io_connect *conn = io_kiocb_to_cmd(req, struct io_connect);
-	struct io_async_msghdr *io;
+	struct sockaddr_storage *addr;
 
 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
 		return -EINVAL;
@@ -1781,17 +1780,17 @@ int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	conn->addr_len =  READ_ONCE(sqe->addr2);
 	conn->in_progress = conn->seen_econnaborted = false;
 
-	io = io_msg_alloc_async(req);
-	if (unlikely(!io))
+	addr = io_uring_alloc_async_data(NULL, req);
+	if (unlikely(!addr))
 		return -ENOMEM;
 
-	return move_addr_to_kernel(conn->addr, conn->addr_len, &io->addr);
+	return move_addr_to_kernel(conn->addr, conn->addr_len, addr);
 }
 
 int io_connect(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_connect *connect = io_kiocb_to_cmd(req, struct io_connect);
-	struct io_async_msghdr *io = req->async_data;
+	struct sockaddr_storage *addr = req->async_data;
 	unsigned file_flags;
 	int ret;
 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -1805,8 +1804,7 @@ int io_connect(struct io_kiocb *req, unsigned int issue_flags)
 
 	file_flags = force_nonblock ? O_NONBLOCK : 0;
 
-	ret = __sys_connect_file(req->file, &io->addr, connect->addr_len,
-				 file_flags);
+	ret = __sys_connect_file(req->file, addr, connect->addr_len, file_flags);
 	if ((ret == -EAGAIN || ret == -EINPROGRESS || ret == -ECONNABORTED)
 	    && force_nonblock) {
 		if (ret == -EINPROGRESS) {
@@ -1835,7 +1833,6 @@ int io_connect(struct io_kiocb *req, unsigned int issue_flags)
 out:
 	if (ret < 0)
 		req_set_fail(req);
-	io_req_msg_cleanup(req, issue_flags);
 	io_req_set_res(req, ret, 0);
 	return IOU_COMPLETE;
 }
@@ -1844,7 +1841,7 @@ int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
 	struct sockaddr __user *uaddr;
-	struct io_async_msghdr *io;
+	struct sockaddr_storage *addr;
 
 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
 		return -EINVAL;
@@ -1852,16 +1849,17 @@ int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	uaddr = u64_to_user_ptr(READ_ONCE(sqe->addr));
 	bind->addr_len =  READ_ONCE(sqe->addr2);
 
-	io = io_msg_alloc_async(req);
-	if (unlikely(!io))
+	addr = io_uring_alloc_async_data(NULL, req);
+	if (unlikely(!addr))
 		return -ENOMEM;
-	return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
+	return move_addr_to_kernel(uaddr, bind->addr_len, addr);
 }
 
+
 int io_bind(struct io_kiocb *req, unsigned int issue_flags)
 {
 	struct io_bind *bind = io_kiocb_to_cmd(req, struct io_bind);
-	struct io_async_msghdr *io = req->async_data;
+	struct sockaddr_storage *addr = req->async_data;
 	struct socket *sock;
 	int ret;
 
@@ -1869,7 +1867,7 @@ int io_bind(struct io_kiocb *req, unsigned int issue_flags)
 	if (unlikely(!sock))
 		return -ENOTSOCK;
 
-	ret = __sys_bind_socket(sock, &io->addr, bind->addr_len);
+	ret = __sys_bind_socket(sock, addr, bind->addr_len);
 	if (ret < 0)
 		req_set_fail(req);
 	io_req_set_res(req, ret, 0);
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 8ea6bd274607..517bad015505 100644
--- a/io_uring/opdef.c
+++ b/io_uring/opdef.c
@@ -204,7 +204,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.pollout		= 1,
 #if defined(CONFIG_NET)
 		.filter_pdu_size	= sizeof_field(struct io_uring_bpf_ctx, connect),
-		.async_size		= sizeof(struct io_async_msghdr),
+		.async_size		= sizeof(struct sockaddr_storage),
 		.prep			= io_connect_prep,
 		.issue			= io_connect,
 		.filter_populate	= io_connect_bpf_populate,
@@ -505,7 +505,7 @@ const struct io_issue_def io_issue_defs[] = {
 		.needs_file		= 1,
 		.prep			= io_bind_prep,
 		.issue			= io_bind,
-		.async_size		= sizeof(struct io_async_msghdr),
+		.async_size		= sizeof(struct sockaddr_storage),
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif
-- 
2.54.0