On 6/14/23 16:15, David Ahern wrote:

On 6/14/23 5:07 AM, Breno Leitao wrote:

quoted

diff --git a/include/linux/net.h b/include/linux/net.h
index 8defc8f1d82e..58dea87077af 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h

@@ -182,6 +182,8 @@ struct proto_ops {
  	int	 	(*compat_ioctl) (struct socket *sock, unsigned int cmd,
  				      unsigned long arg);
  #endif
+	int		(*uring_cmd)(struct socket *sock, struct io_uring_cmd *cmd,
+				     unsigned int issue_flags);
  	int		(*gettstamp) (struct socket *sock, void __user *userstamp,
  				      bool timeval, bool time32);
  	int		(*listen)    (struct socket *sock, int len);

diff --git a/include/net/sock.h b/include/net/sock.h
index 62a1b99da349..a49b8b19292b 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h

@@ -111,6 +111,7 @@ typedef struct {
  struct sock;
  struct proto;
  struct net;
+struct io_uring_cmd;
  
  typedef __u32 __bitwise __portpair;
  typedef __u64 __bitwise __addrpair;

@@ -1259,6 +1260,9 @@ struct proto {
  
  	int			(*ioctl)(struct sock *sk, int cmd,
  					 int *karg);
+	int			(*uring_cmd)(struct sock *sk,
+					     struct io_uring_cmd *cmd,
+					     unsigned int issue_flags);
  	int			(*init)(struct sock *sk);
  	void			(*destroy)(struct sock *sk);
  	void			(*shutdown)(struct sock *sk, int how);

@@ -1934,6 +1938,8 @@ int sock_common_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
  			int flags);
  int sock_common_setsockopt(struct socket *sock, int level, int optname,
  			   sockptr_t optval, unsigned int optlen);
+int sock_common_uring_cmd(struct socket *sock, struct io_uring_cmd *cmd,
+			  unsigned int issue_flags);
  
  void sk_common_release(struct sock *sk);
  

diff --git a/net/core/sock.c b/net/core/sock.c
index 1df7e432fec5..339fa74db60f 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c

@@ -3668,6 +3668,18 @@ int sock_common_setsockopt(struct socket *sock, int level, int optname,
  }
  EXPORT_SYMBOL(sock_common_setsockopt);
  
+int sock_common_uring_cmd(struct socket *sock, struct io_uring_cmd *cmd,
+			  unsigned int issue_flags)
+{
+	struct sock *sk = sock->sk;
+
+	if (!sk->sk_prot || !sk->sk_prot->uring_cmd)
+		return -EOPNOTSUPP;
+
+	return sk->sk_prot->uring_cmd(sk, cmd, issue_flags);
+}
+EXPORT_SYMBOL(sock_common_uring_cmd);
+

io_uring is just another in-kernel user of sockets. There is no reason
for io_uring references to be in core net code. It should be using
exposed in-kernel APIs and doing any translation of its op codes in
io_uring/  code.

That callback is all about file dependent operations, just like ioctl.
And as the patch in question is doing socket specific stuff, I think
architecturally it fits well. I also believe Breno wants to extend it
later to support more operations.

Sockets are a large chunk of use cases, it can be implemented as a
separate io_uring request type if nothing else works, but in general
that might not be as scalable.

-- 
Pavel Begunkov