On Sat, Jul 01, 2023 at 09:39:43AM +0300, Arseniy Krasnov wrote:
For AF_VSOCK, zerocopy tx mode depends on transport, so this option must
be set in AF_VSOCK implementation where transport is accessible (if
transport is not set during setting SO_ZEROCOPY: for example socket is
not connected, then SO_ZEROCOPY will be enabled, but once transport will
be assigned, support of this type of transmission will be checked).
To handle SO_ZEROCOPY, AF_VSOCK implementation uses SOCK_CUSTOM_SOCKOPT
bit, thus handling SOL_SOCKET option operations, but all of them except
SO_ZEROCOPY will be forwarded to the generic handler by calling
'sock_setsockopt()'.
Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
---
Changelog:
v4 -> v5:
* This patch is totally reworked. Previous version added check for
PF_VSOCK directly to 'net/core/sock.c', thus allowing to set
SO_ZEROCOPY for AF_VSOCK type of socket. This new version catches
attempt to set SO_ZEROCOPY in 'af_vsock.c'. All other options
except SO_ZEROCOPY are forwarded to generic handler. Only this
option is processed in 'af_vsock.c'. Handling this option includes
access to transport to check that MSG_ZEROCOPY transmission is
supported by the current transport (if it is set, if not - transport
will be checked during 'connect()').
Yeah, great, this is much better!
net/vmw_vsock/af_vsock.c | 44 ++++++++++++++++++++++++++++++++++++++--
1 file changed, 42 insertions(+), 2 deletions(-)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index da22ae0ef477..8acc77981d01 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1406,8 +1406,18 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr,
goto out;
}
- if (vsock_msgzerocopy_allow(transport))
+ if (!vsock_msgzerocopy_allow(transport)) {
Can you leave `if (vsock_msgzerocopy_allow(transport))` and just add
the else branch with this new check?
if (vsock_msgzerocopy_allow(transport)) {
...
} else if (sock_flag(sk, SOCK_ZEROCOPY)) {
...
}
+ /* If this option was set before 'connect()',
+ * when transport was unknown, check that this
+ * feature is supported here.
+ */
+ if (sock_flag(sk, SOCK_ZEROCOPY)) {
+ err = -EOPNOTSUPP;
+ goto out;
+ }
+ } else {
set_bit(SOCK_SUPPORT_ZC, &sk->sk_socket->flags);
+ }
err = vsock_auto_bind(vsk);
if (err)
@@ -1643,7 +1653,7 @@ static int vsock_connectible_setsockopt(struct socket *sock,
const struct vsock_transport *transport;
u64 val;
- if (level != AF_VSOCK)
+ if (level != AF_VSOCK && level != SOL_SOCKET)
return -ENOPROTOOPT;
#define COPY_IN(_v) \
@@ -1666,6 +1676,34 @@ static int vsock_connectible_setsockopt(struct socket *sock,
transport = vsk->transport;
+ if (level == SOL_SOCKET) {
We could reduce the indentation here:
if (optname != SO_ZEROCOPY) {
release_sock(sk);
return sock_setsockopt(sock, level, optname, optval, optlen);
}
Then remove the next indentation.
+ if (optname == SO_ZEROCOPY) {
+ int zc_val;
`zerocopy` is more readable.
+
+ /* Use 'int' type here, because variable to
+ * set this option usually has this type.
+ */
+ COPY_IN(zc_val);
+
+ if (zc_val < 0 || zc_val > 1) {
+ err = -EINVAL;
+ goto exit;
+ }
+
+ if (transport && !vsock_msgzerocopy_allow(transport)) {
+ err = -EOPNOTSUPP;
+ goto exit;
+ }
+
+ sock_valbool_flag(sk, SOCK_ZEROCOPY,
+ zc_val ? true : false);
Why not using directly `zc_val`?
The 3rd param of sock_valbool_flag() is an int.
+ goto exit;
+ }
+
+ release_sock(sk);
+ return sock_setsockopt(sock, level, optname, optval, optlen);
+ }
+
switch (optname) {
case SO_VM_SOCKETS_BUFFER_SIZE:
COPY_IN(val);
@@ -2321,6 +2359,8 @@ static int vsock_create(struct net *net, struct socket *sock,
}
}
+ set_bit(SOCK_CUSTOM_SOCKOPT, &sk->sk_socket->flags);
+
vsock_insert_unbound(vsk);
return 0;
--
2.25.1
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