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

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

Signed-off-by: Gabriel Krisman Bertazi <[email protected]>
---
 io_uring/net.c   | 15 +++++++--------
 io_uring/net.h   |  4 ++++
 io_uring/opdef.c |  4 ++--
 3 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index cceb5c1409ca..1da811100132 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1677,7 +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 io_async_sockaddr *iomsg = req->async_data;
 	struct sockaddr_storage *ss = &iomsg->addr;
 
 	/*
@@ -1772,7 +1772,7 @@ 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 io_async_sockaddr *io;
 
 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
 		return -EINVAL;
@@ -1781,7 +1781,7 @@ 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);
+	io = io_uring_alloc_async_data(NULL, req);
 	if (unlikely(!io))
 		return -ENOMEM;
 
@@ -1791,7 +1791,7 @@ int io_connect_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 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 io_async_sockaddr *io = req->async_data;
 	unsigned file_flags;
 	int ret;
 	bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
@@ -1835,7 +1835,6 @@ 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 +1843,7 @@ 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 io_async_sockaddr *io;
 
 	if (sqe->len || sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
 		return -EINVAL;
@@ -1852,7 +1851,7 @@ 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);
+	io = io_uring_alloc_async_data(NULL, req);
 	if (unlikely(!io))
 		return -ENOMEM;
 	return move_addr_to_kernel(uaddr, bind->addr_len, &io->addr);
@@ -1861,7 +1860,7 @@ int io_bind_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 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 io_async_sockaddr *io = req->async_data;
 	struct socket *sock;
 	int ret;
 
diff --git a/io_uring/net.h b/io_uring/net.h
index 51fda715d3c0..b296ec4eefb2 100644
--- a/io_uring/net.h
+++ b/io_uring/net.h
@@ -5,6 +5,10 @@
 #include <linux/io_uring_types.h>
 #include <uapi/linux/io_uring/bpf_filter.h>
 
+struct io_async_sockaddr {
+	struct sockaddr_storage		addr;
+};
+
 struct io_async_msghdr {
 #if defined(CONFIG_NET)
 	struct iou_vec				vec;
diff --git a/io_uring/opdef.c b/io_uring/opdef.c
index 8ea6bd274607..ffa28224cc8f 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 io_async_sockaddr),
 		.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 io_async_sockaddr),
 #else
 		.prep			= io_eopnotsupp_prep,
 #endif
-- 
2.54.0