NLM failover - client notification setup

@@ -102,6 +102,7 @@ static inline void svc_putu32(struct kve
 	iov->iov_len += sizeof(u32);
 }
 
+typedef __u32  svc_addr_t;
 	
 /*
  * The context of a single thread, including the request currently being

@@ -138,8 +139,8 @@ struct svc_rqst {
 	unsigned short
 				rq_secure  : 1;	/* secure port */
 
-
-	__u32			rq_daddr;	/* dest addr of request - reply from here */
+	svc_addr_t		rq_daddr;	/* dest addr of request 
+						   - reply from here */
 
 	void *			rq_argp;	/* decoded arguments */
 	void *			rq_resp;	/* xdr'd results */

@@ -39,12 +39,13 @@
 struct nlm_host {
 	struct nlm_host *	h_next;		/* linked list (hash table) */
 	struct sockaddr_in	h_addr;		/* peer address */
+	svc_addr_t		h_server;	/* server ip for NLM failover */
 	struct rpc_clnt	*	h_rpcclnt;	/* RPC client to talk to peer */
 	char			h_name[20];	/* remote hostname */
 	u32			h_version;	/* interface version */
 	unsigned short		h_proto;	/* transport proto */
 	unsigned short		h_reclaiming : 1,
-				h_server     : 1, /* server side, not client side */
+				h_notused    : 1, 
 				h_inuse      : 1,
 				h_killed     : 1,
 				h_monitored  : 1;

@@ -172,7 +173,7 @@ int		  nlmclnt_reclaim(struct nlm_host *
  */
 struct nlm_host * nlmclnt_lookup_host(struct sockaddr_in *, int, int);
 struct nlm_host * nlmsvc_lookup_host(struct svc_rqst *);
-struct nlm_host * nlm_lookup_host(int server, struct sockaddr_in *, int, int);
+struct nlm_host * nlm_lookup_host(svc_addr_t server, struct sockaddr_in *, int, int);
 struct rpc_clnt * nlm_bind_host(struct nlm_host *);
 void		  nlm_rebind_host(struct nlm_host *);
 struct nlm_host * nlm_get_host(struct nlm_host *);

@@ -25,6 +25,7 @@
  */
 struct nsm_args {
 	u32		addr;		/* remote address */
+	u32		serv;		/* server ip address */
 	u32		prog;		/* RPC callback info */
 	u32		vers;
 	u32		proc;

@@ -454,6 +454,7 @@ svc_recvfrom(struct svc_rqst *rqstp, str
 	struct msghdr	msg;
 	struct socket	*sock;
 	int		len, alen;
+	struct sockaddr_in   daddr;
 
 	rqstp->rq_addrlen = sizeof(rqstp->rq_addr);
 	sock = rqstp->rq_sock->sk_sock;

@@ -474,6 +475,10 @@ svc_recvfrom(struct svc_rqst *rqstp, str
 	alen = sizeof(rqstp->rq_addr);
 	sock->ops->getname(sock, (struct sockaddr *)&rqstp->rq_addr, &alen, 1);
 
+	/* add server ip for nlm lock failover */
+	sock->ops->getname(sock, (struct sockaddr *)&daddr, &alen, 0);
+	rqstp->rq_daddr = daddr.sin_addr.s_addr;
+
 	dprintk("svc: socket %p recvfrom(%p, %Zu) = %d\n",
 		rqstp->rq_sock, iov[0].iov_base, iov[0].iov_len, len);
 

@@ -132,6 +132,10 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp
 
 	resp->cookie = argp->cookie;
 
+	if (argp->reclaim) {
+		printk("reclaim arrives before retrieve_args\n");
+	}
+
 	/* Don't accept new lock requests during grace period */
 	if ((nlmsvc_grace_period || (nlm4svc_fo_grace_period(argp))) 
 			&& !argp->reclaim) {

@@ -140,7 +144,7 @@ nlm4svc_proc_lock(struct svc_rqst *rqstp
 	}
 
 	/* Obtain client and file */
-	if (resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file))
+	if ((resp->status = nlm4svc_retrieve_args(rqstp, argp, &host, &file)))
 		return rpc_success;
 
 #if 0

@@ -463,7 +467,7 @@ nlm4svc_proc_sm_notify(struct svc_rqst *
 	} else {
 		/* If we run on an NFS server, delete all locks held by the client */
 
-		if ((host = nlm_lookup_host(1, &saddr, prot, vers)) != NULL) {
+		if ((host = nlm_lookup_host(rqstp->rq_daddr, &saddr, prot, vers)) != NULL) {
 			nlmsvc_free_host_resources(host);
 			nlm_release_host(host);
 		}

@@ -491,7 +491,7 @@ nlmsvc_proc_sm_notify(struct svc_rqst *r
 		}
 	} else {
 		/* If we run on an NFS server, delete all locks held by the client */
-		if ((host = nlm_lookup_host(1, &saddr, prot, vers)) != NULL) {
+		if ((host = nlm_lookup_host(rqstp->rq_daddr, &saddr, prot, vers)) != NULL) {
 			nlmsvc_free_host_resources(host);
 			nlm_release_host(host);
 		}

@@ -47,7 +47,8 @@ nsm_mon_unmon(struct nlm_host *host, u32
 	}
 
 	args.addr = host->h_addr.sin_addr.s_addr;
-	args.proto= (host->h_proto<<1) | host->h_server;
+	args.serv = host->h_server;
+	args.proto= (host->h_proto<<1) | (host->h_server ? 1:0);
 	args.prog = NLM_PROGRAM;
 	args.vers = host->h_version;
 	args.proc = NLMPROC_NSM_NOTIFY;

@@ -135,6 +136,13 @@ out_err:
 	return clnt;
 }
 
+/* We want "buffer" in xdr_encode_common() to hold
+ * either the system_utsname.nodename string (__NEW_UTS_LEN+1)
+ * or IPv4 dot notation (16 bytes+1) for now.
+ */ 
+
+#define	XDR_ENCODE_BUF_LEN __NEW_UTS_LEN+1	
+
 /*
  * XDR functions for NSM.
  */

@@ -142,7 +150,7 @@ out_err:
 static u32 *
 xdr_encode_common(struct rpc_rqst *rqstp, u32 *p, struct nsm_args *argp)
 {
-	char	buffer[20];
+	char	buffer[XDR_ENCODE_BUF_LEN];
 
 	/*
 	 * Use the dotted-quad IP address of the remote host as

@@ -151,8 +159,13 @@ xdr_encode_common(struct rpc_rqst *rqstp
 	 * so this works alright.
 	 */
 	sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->addr));
-	if (!(p = xdr_encode_string(p, buffer))
-	 || !(p = xdr_encode_string(p, system_utsname.nodename)))
+	if (!(p = xdr_encode_string(p, buffer)))
+		return ERR_PTR(-EIO);
+	if (argp->serv)
+		sprintf(buffer, "%u.%u.%u.%u", NIPQUAD(argp->serv));
+	else
+		sprintf(buffer, "%s", system_utsname.nodename);
+	if (!(p = xdr_encode_string(p, buffer)))
 		return ERR_PTR(-EIO);
 	*p++ = htonl(argp->prog);
 	*p++ = htonl(argp->vers);

@@ -51,7 +51,7 @@ nlmclnt_lookup_host(struct sockaddr_in *
 struct nlm_host *
 nlmsvc_lookup_host(struct svc_rqst *rqstp)
 {
-	return nlm_lookup_host(1, &rqstp->rq_addr,
+	return nlm_lookup_host(rqstp->rq_daddr, &rqstp->rq_addr,
 			       rqstp->rq_prot, rqstp->rq_vers);
 }
 

@@ -59,7 +59,7 @@ nlmsvc_lookup_host(struct svc_rqst *rqst
  * Common host lookup routine for server & client
  */
 struct nlm_host *
-nlm_lookup_host(int server, struct sockaddr_in *sin,
+nlm_lookup_host(svc_addr_t server, struct sockaddr_in *sin,
 					int proto, int version)
 {
 	struct nlm_host	*host, **hp;