sock: remove zerocopy sockopt restriction on closed tcp state

Socket option SO_ZEROCOPY determines whether the kernel ignores or
processes flag MSG_ZEROCOPY on subsequent send calls. This to avoid
changing behavior for legacy processes.

Limiting the state change to closed sockets is annoying with passive
sockets and not necessary for correctness. Once created, zerocopy skbs
are processed based on their private state, not this socket flag.

Remove the constraint.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/Documentation/networking/msg_zerocopy.rst b/Documentation/networking/msg_zerocopy.rst
index 291a012649678035b5d0fdc306904093ceedf610..fe46d4867e2dbfa4cde05cc0b900c157d99b67d9 100644 (file)
--- a/Documentation/networking/msg_zerocopy.rst
+++ b/Documentation/networking/msg_zerocopy.rst
@@ -72,11 +72,6 @@ this flag, a process must first signal intent by setting a socket option:
        if (setsockopt(fd, SOL_SOCKET, SO_ZEROCOPY, &one, sizeof(one)))
                error(1, errno, "setsockopt zerocopy");
 
-Setting the socket option only works when the socket is in its initial
-(TCP_CLOSED) state.  Trying to set the option for a socket returned by accept(),
-for example, will lead to an EBUSY error. In this case, the option should be set
-to the listening socket and it will be inherited by the accepted sockets.
-
 Transmission
 ------------
 

diff --git a/net/core/sock.c b/net/core/sock.c
index 27f218bba43fcf27bc6e42f018beec12d39c1930..a8962d9128953e20815165f55f1e1ec83daea0c6 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1052,8 +1052,6 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
                if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6) {
                        if (sk->sk_protocol != IPPROTO_TCP)
                                ret = -ENOTSUPP;
-                       else if (sk->sk_state != TCP_CLOSE)
-                               ret = -EBUSY;
                } else if (sk->sk_family != PF_RDS) {
                        ret = -ENOTSUPP;
                }