Re: [PATCH net-next] net: socket: add the case sock_no_xxx support
From: <hidden>
Date: 2021-09-18 02:54:23
Also in:
lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
September 18, 2021 9:33 AM, "Jakub Kicinski" [off-list ref] wrote:
On Thu, 16 Sep 2021 20:29:43 +0800 Yajun Deng wrote:quoted
Those sock_no_{mmap, socketpair, listen, accept, connect, shutdown, sendpage} functions are used many times in struct proto_ops, but they are meaningless. So we can add them support in socket and delete them in struct proto_ops.So the reason to do this is.. what exactly? Removing a couple empty helpers (which is not even part of this patch)? I'm not sold, sorry.
When we define a struct proto_ops xxx, we only need to assign meaningful member variables that we need.
Those {mmap, socketpair, listen, accept, connect, shutdown, sendpage} members we don't need assign
it if we don't need. We just need do once in socket, not in every struct proto_ops.
These members are assigned meaningless values far more often than meaningful ones, so this patch I used likely(!!sock->ops->xxx) for this case. This is the reason why I send this patch.
I would send a set of patchs remove most of the meaningless members assigned rather than remove sock_no_{mmap, socketpair, listen, accept, connect, shutdown, sendpage} functions if this patch was accepted.
e.g.
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 1d816a5fd3eb..86422eb440cb 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c@@ -1059,20 +1059,16 @@ const struct proto_ops inet_dgram_ops = { .release = inet_release, .bind = inet_bind, .connect = inet_dgram_connect, - .socketpair = sock_no_socketpair, - .accept = sock_no_accept, --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c
@@ -1059,20 +1059,16 @@ const struct proto_ops inet_dgram_ops = { .release = inet_release, .bind = inet_bind, .connect = inet_dgram_connect, - .socketpair = sock_no_socketpair, - .accept = sock_no_accept, .getname = inet_getname, .gettstamp = sock_gettstamp, - .listen = sock_no_listen, .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = inet_sendmsg, .read_sock = udp_read_sock, .recvmsg = inet_recvmsg, - .mmap = sock_no_mmap, .sendpage = inet_sendpage, .set_peek_off = sk_set_peek_off, #ifdef CONFIG_COMPAT
@@ -1091,19 +1087,15 @@ static const struct proto_ops inet_sockraw_ops = { .release = inet_release, .bind = inet_bind, .connect = inet_dgram_connect, - .socketpair = sock_no_socketpair, - .accept = sock_no_accept, .getname = inet_getname, .poll = datagram_poll, .ioctl = inet_ioctl, .gettstamp = sock_gettstamp, - .listen = sock_no_listen, .shutdown = inet_shutdown, .setsockopt = sock_common_setsockopt, .getsockopt = sock_common_getsockopt, .sendmsg = inet_sendmsg, .recvmsg = inet_recvmsg, - .mmap = sock_no_mmap, .sendpage = inet_sendpage, #ifdef CONFIG_COMPAT .compat_ioctl = inet_compat_ioctl,