[PATCH] knfsd: SUNRPC: Cache remote peer's address in svc_sock

The remote peer's address won't change after the socket has been accepted.  We
don't need to call ->getname on every incoming request.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: Aurelien Charbon <aurelien.charbon@ext.bull.net>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/sunrpc/svcsock.h

@@ -57,6 +57,9 @@ struct svc_sock {
 
 	/* cache of various info for TCP sockets */
 	void			*sk_info_authunix;
+
+	struct sockaddr_storage	sk_remote;	/* remote peer's address */
+	int			sk_remotelen;	/* length of address */
 };
 
 /*

net/sunrpc/svcsock.c

@@ -568,12 +568,13 @@ svc_recv_available(struct svc_sock *svsk)
 static int
 svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
 {
+	struct svc_sock *svsk = rqstp->rq_sock;
 	struct msghdr	msg;
 	struct socket	*sock;
-	int		len, alen;
+	int		len;
 
 	rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
-	sock = rqstp->rq_sock->sk_sock;
+	sock = svsk->sk_sock;
 
 	msg.msg_name    = &rqstp->rq_addr;
 	msg.msg_namelen = sizeof(rqstp->rq_addr);
@@ -585,11 +586,9 @@ svc_recvfrom(struct svc_rqst *rqstp, struct kvec *iov, int nr, int buflen)
 	len = kernel_recvmsg(sock, &msg, iov, nr, buflen, MSG_DONTWAIT);
 
 	/* sock_recvmsg doesn't fill in the name/namelen, so we must..
-	 * possibly we should cache this in the svc_sock structure
-	 * at accept time. FIXME
 	 */
-	alen = sizeof(rqstp->rq_addr);
-	kernel_getpeername(sock, (struct sockaddr *)&rqstp->rq_addr, &alen);
+	memcpy(&rqstp->rq_addr, &svsk->sk_remote, svsk->sk_remotelen);
+	rqstp->rq_addrlen = svsk->sk_remotelen;
 
 	dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
 		rqstp->rq_sock, iov[0].iov_base, iov[0].iov_len, len);
@@ -938,6 +937,9 @@ svc_tcp_accept(struct svc_sock *svsk)
 	if (!(newsvsk = svc_setup_socket(serv, newsock, &err,
 				 (SVC_SOCK_ANONYMOUS | SVC_SOCK_TEMPORARY))))
 		goto failed;
+	memcpy(&newsvsk->sk_remote, &sin, slen);
+	newsvsk->sk_remotelen = slen;
+
 	svc_sock_received(newsvsk);
 
 	/* make sure that we don't have too many active connections.