net: also flag accepted sockets supporting msghdr originated zerocopy

Without this only the client initiated tcp sockets have SOCK_SUPPORT_ZC.
The listening socket on the server also has it, but the accepted
connections didn't, which meant IORING_OP_SEND[MSG]_ZC will always
fails with -EOPNOTSUPP.

Fixes: e993ffe3da4b ("net: flag sockets supporting msghdr originated zerocopy")
Cc: <stable@vger.kernel.org> # 6.0
CC: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/io-uring/20221024141503.22b4e251@kernel.org/T/#m38aa19b0b825758fb97860a38ad13122051f9dda
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 3dd02396517df599cf4ff3b9ab8463ea959770a1..4728087c42a5cc879d25a935e73d162b4db74e03 100644 (file)
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -754,6 +754,8 @@ int inet_accept(struct socket *sock, struct socket *newsock, int flags,
                  (TCPF_ESTABLISHED | TCPF_SYN_RECV |
                  TCPF_CLOSE_WAIT | TCPF_CLOSE)));
 
+       if (test_bit(SOCK_SUPPORT_ZC, &sock->flags))
+               set_bit(SOCK_SUPPORT_ZC, &newsock->flags);
        sock_graft(sk2, newsock);
 
        newsock->state = SS_CONNECTED;