io_uring: separate header for exported net bits

We're exporting some io_uring bits to networking, e.g. for implementing
a net callback for io_uring cmds, but we don't want to expose more than
needed. Add a separate header for networking.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
Link: https://lore.kernel.org/r/20240409210554.1878789-1-dw@davidwei.uk
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

include/linux/io_uring.h

@@ -11,7 +11,6 @@ void __io_uring_cancel(bool cancel_all);
 void __io_uring_free(struct task_struct *tsk);
 void io_uring_unreg_ringfd(void);
 const char *io_uring_get_opcode(u8 opcode);
-int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
 bool io_is_uring_fops(struct file *file);
 
 static inline void io_uring_files_cancel(void)
@@ -45,11 +44,6 @@ static inline const char *io_uring_get_opcode(u8 opcode)
 {
 	return "";
 }
-static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
-				    unsigned int issue_flags)
-{
-	return -EOPNOTSUPP;
-}
 static inline bool io_is_uring_fops(struct file *file)
 {
 	return false;

include/linux/io_uring/net.h

@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _LINUX_IO_URING_NET_H
+#define _LINUX_IO_URING_NET_H
+
+struct io_uring_cmd;
+
+#if defined(CONFIG_IO_URING)
+int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
+
+#else
+static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
+				    unsigned int issue_flags)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+#endif

io_uring/uring_cmd.c

@@ -3,6 +3,7 @@
 #include <linux/errno.h>
 #include <linux/file.h>
 #include <linux/io_uring/cmd.h>
+#include <linux/io_uring/net.h>
 #include <linux/security.h>
 #include <linux/nospec.h>
 #include <net/sock.h>

net/socket.c

@@ -88,7 +88,7 @@
 #include <linux/xattr.h>
 #include <linux/nospec.h>
 #include <linux/indirect_call_wrapper.h>
-#include <linux/io_uring.h>
+#include <linux/io_uring/net.h>
 
 #include <linux/uaccess.h>
 #include <asm/unistd.h>