Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index d13e05f..d11b705 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * linux/net/sunrpc/svc.c
  *
@@ -993,6 +994,58 @@
 	return error;
 }
 
+int svc_rpcbind_set_version(struct net *net,
+			    const struct svc_program *progp,
+			    u32 version, int family,
+			    unsigned short proto,
+			    unsigned short port)
+{
+	dprintk("svc: svc_register(%sv%d, %s, %u, %u)\n",
+		progp->pg_name, version,
+		proto == IPPROTO_UDP?  "udp" : "tcp",
+		port, family);
+
+	return __svc_register(net, progp->pg_name, progp->pg_prog,
+				version, family, proto, port);
+
+}
+EXPORT_SYMBOL_GPL(svc_rpcbind_set_version);
+
+int svc_generic_rpcbind_set(struct net *net,
+			    const struct svc_program *progp,
+			    u32 version, int family,
+			    unsigned short proto,
+			    unsigned short port)
+{
+	const struct svc_version *vers = progp->pg_vers[version];
+	int error;
+
+	if (vers == NULL)
+		return 0;
+
+	if (vers->vs_hidden) {
+		dprintk("svc: svc_register(%sv%d, %s, %u, %u)"
+			" (but not telling portmap)\n",
+			progp->pg_name, version,
+			proto == IPPROTO_UDP?  "udp" : "tcp",
+			port, family);
+		return 0;
+	}
+
+	/*
+	 * Don't register a UDP port if we need congestion
+	 * control.
+	 */
+	if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
+		return 0;
+
+	error = svc_rpcbind_set_version(net, progp, version,
+					family, proto, port);
+
+	return (vers->vs_rpcb_optnl) ? 0 : error;
+}
+EXPORT_SYMBOL_GPL(svc_generic_rpcbind_set);
+
 /**
  * svc_register - register an RPC service with the local portmapper
  * @serv: svc_serv struct for the service to register
@@ -1008,7 +1061,6 @@
 		 const unsigned short port)
 {
 	struct svc_program	*progp;
-	const struct svc_version *vers;
 	unsigned int		i;
 	int			error = 0;
 
@@ -1018,37 +1070,9 @@
 
 	for (progp = serv->sv_program; progp; progp = progp->pg_next) {
 		for (i = 0; i < progp->pg_nvers; i++) {
-			vers = progp->pg_vers[i];
-			if (vers == NULL)
-				continue;
 
-			dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",
-					progp->pg_name,
-					i,
-					proto == IPPROTO_UDP?  "udp" : "tcp",
-					port,
-					family,
-					vers->vs_hidden ?
-					" (but not telling portmap)" : "");
-
-			if (vers->vs_hidden)
-				continue;
-
-			/*
-			 * Don't register a UDP port if we need congestion
-			 * control.
-			 */
-			if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
-				continue;
-
-			error = __svc_register(net, progp->pg_name, progp->pg_prog,
-						i, family, proto, port);
-
-			if (vers->vs_rpcb_optnl) {
-				error = 0;
-				continue;
-			}
-
+			error = progp->pg_rpcbind_set(net, progp, i,
+					family, proto, port);
 			if (error < 0) {
 				printk(KERN_WARNING "svc: failed to register "
 					"%sv%u RPC service (errno %d).\n",
@@ -1144,6 +1168,114 @@
 static __printf(2,3) void svc_printk(struct svc_rqst *rqstp, const char *fmt, ...) {}
 #endif
 
+__be32
+svc_return_autherr(struct svc_rqst *rqstp, __be32 auth_err)
+{
+	set_bit(RQ_AUTHERR, &rqstp->rq_flags);
+	return auth_err;
+}
+EXPORT_SYMBOL_GPL(svc_return_autherr);
+
+static __be32
+svc_get_autherr(struct svc_rqst *rqstp, __be32 *statp)
+{
+	if (test_and_clear_bit(RQ_AUTHERR, &rqstp->rq_flags))
+		return *statp;
+	return rpc_auth_ok;
+}
+
+static int
+svc_generic_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+{
+	struct kvec *argv = &rqstp->rq_arg.head[0];
+	struct kvec *resv = &rqstp->rq_res.head[0];
+	const struct svc_procedure *procp = rqstp->rq_procinfo;
+
+	/*
+	 * Decode arguments
+	 * XXX: why do we ignore the return value?
+	 */
+	if (procp->pc_decode &&
+	    !procp->pc_decode(rqstp, argv->iov_base)) {
+		*statp = rpc_garbage_args;
+		return 1;
+	}
+
+	*statp = procp->pc_func(rqstp);
+
+	if (*statp == rpc_drop_reply ||
+	    test_bit(RQ_DROPME, &rqstp->rq_flags))
+		return 0;
+
+	if (test_bit(RQ_AUTHERR, &rqstp->rq_flags))
+		return 1;
+
+	if (*statp != rpc_success)
+		return 1;
+
+	/* Encode reply */
+	if (procp->pc_encode &&
+	    !procp->pc_encode(rqstp, resv->iov_base + resv->iov_len)) {
+		dprintk("svc: failed to encode reply\n");
+		/* serv->sv_stats->rpcsystemerr++; */
+		*statp = rpc_system_err;
+	}
+	return 1;
+}
+
+__be32
+svc_generic_init_request(struct svc_rqst *rqstp,
+		const struct svc_program *progp,
+		struct svc_process_info *ret)
+{
+	const struct svc_version *versp = NULL;	/* compiler food */
+	const struct svc_procedure *procp = NULL;
+
+	if (rqstp->rq_vers >= progp->pg_nvers )
+		goto err_bad_vers;
+	versp = progp->pg_vers[rqstp->rq_vers];
+	if (!versp)
+		goto err_bad_vers;
+
+	/*
+	 * Some protocol versions (namely NFSv4) require some form of
+	 * congestion control.  (See RFC 7530 section 3.1 paragraph 2)
+	 * In other words, UDP is not allowed. We mark those when setting
+	 * up the svc_xprt, and verify that here.
+	 *
+	 * The spec is not very clear about what error should be returned
+	 * when someone tries to access a server that is listening on UDP
+	 * for lower versions. RPC_PROG_MISMATCH seems to be the closest
+	 * fit.
+	 */
+	if (versp->vs_need_cong_ctrl && rqstp->rq_xprt &&
+	    !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
+		goto err_bad_vers;
+
+	if (rqstp->rq_proc >= versp->vs_nproc)
+		goto err_bad_proc;
+	rqstp->rq_procinfo = procp = &versp->vs_proc[rqstp->rq_proc];
+	if (!procp)
+		goto err_bad_proc;
+
+	/* Initialize storage for argp and resp */
+	memset(rqstp->rq_argp, 0, procp->pc_argsize);
+	memset(rqstp->rq_resp, 0, procp->pc_ressize);
+
+	/* Bump per-procedure stats counter */
+	versp->vs_count[rqstp->rq_proc]++;
+
+	ret->dispatch = versp->vs_dispatch;
+	return rpc_success;
+err_bad_vers:
+	ret->mismatch.lovers = progp->pg_lovers;
+	ret->mismatch.hivers = progp->pg_hivers;
+	return rpc_prog_mismatch;
+err_bad_proc:
+	return rpc_proc_unavail;
+}
+EXPORT_SYMBOL_GPL(svc_generic_init_request);
+
 /*
  * Common routine for processing the RPC request.
  */
@@ -1151,11 +1283,11 @@
 svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
 {
 	struct svc_program	*progp;
-	const struct svc_version *versp = NULL;	/* compiler food */
 	const struct svc_procedure *procp = NULL;
 	struct svc_serv		*serv = rqstp->rq_server;
+	struct svc_process_info process;
 	__be32			*statp;
-	u32			prog, vers, proc;
+	u32			prog, vers;
 	__be32			auth_stat, rpc_stat;
 	int			auth_res;
 	__be32			*reply_statp;
@@ -1171,9 +1303,6 @@
 	set_bit(RQ_USEDEFERRAL, &rqstp->rq_flags);
 	clear_bit(RQ_DROPME, &rqstp->rq_flags);
 
-	/* Setup reply header */
-	rqstp->rq_xprt->xpt_ops->xpo_prep_reply_hdr(rqstp);
-
 	svc_putu32(resv, rqstp->rq_xid);
 
 	vers = svc_getnl(argv);
@@ -1190,8 +1319,8 @@
 	svc_putnl(resv, 0);		/* ACCEPT */
 
 	rqstp->rq_prog = prog = svc_getnl(argv);	/* program number */
-	rqstp->rq_vers = vers = svc_getnl(argv);	/* version number */
-	rqstp->rq_proc = proc = svc_getnl(argv);	/* procedure number */
+	rqstp->rq_vers = svc_getnl(argv);	/* version number */
+	rqstp->rq_proc = svc_getnl(argv);	/* procedure number */
 
 	for (progp = serv->sv_program; progp; progp = progp->pg_next)
 		if (prog == progp->pg_prog)
@@ -1229,29 +1358,22 @@
 	if (progp == NULL)
 		goto err_bad_prog;
 
-	if (vers >= progp->pg_nvers ||
-	  !(versp = progp->pg_vers[vers]))
+	rpc_stat = progp->pg_init_request(rqstp, progp, &process);
+	switch (rpc_stat) {
+	case rpc_success:
+		break;
+	case rpc_prog_unavail:
+		goto err_bad_prog;
+	case rpc_prog_mismatch:
 		goto err_bad_vers;
-
-	/*
-	 * Some protocol versions (namely NFSv4) require some form of
-	 * congestion control.  (See RFC 7530 section 3.1 paragraph 2)
-	 * In other words, UDP is not allowed. We mark those when setting
-	 * up the svc_xprt, and verify that here.
-	 *
-	 * The spec is not very clear about what error should be returned
-	 * when someone tries to access a server that is listening on UDP
-	 * for lower versions. RPC_PROG_MISMATCH seems to be the closest
-	 * fit.
-	 */
-	if (versp->vs_need_cong_ctrl &&
-	    !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
-		goto err_bad_vers;
-
-	procp = versp->vs_proc + proc;
-	if (proc >= versp->vs_nproc || !procp->pc_func)
+	case rpc_proc_unavail:
 		goto err_bad_proc;
-	rqstp->rq_procinfo = procp;
+	}
+
+	procp = rqstp->rq_procinfo;
+	/* Should this check go into the dispatcher? */
+	if (!procp || !procp->pc_func)
+		goto err_bad_proc;
 
 	/* Syntactic check complete */
 	serv->sv_stats->rpccnt++;
@@ -1261,13 +1383,6 @@
 	statp = resv->iov_base +resv->iov_len;
 	svc_putnl(resv, RPC_SUCCESS);
 
-	/* Bump per-procedure stats counter */
-	versp->vs_count[proc]++;
-
-	/* Initialize storage for argp and resp */
-	memset(rqstp->rq_argp, 0, procp->pc_argsize);
-	memset(rqstp->rq_resp, 0, procp->pc_ressize);
-
 	/* un-reserve some of the out-queue now that we have a
 	 * better idea of reply size
 	 */
@@ -1275,43 +1390,18 @@
 		svc_reserve_auth(rqstp, procp->pc_xdrressize<<2);
 
 	/* Call the function that processes the request. */
-	if (!versp->vs_dispatch) {
-		/*
-		 * Decode arguments
-		 * XXX: why do we ignore the return value?
-		 */
-		if (procp->pc_decode &&
-		    !procp->pc_decode(rqstp, argv->iov_base))
+	if (!process.dispatch) {
+		if (!svc_generic_dispatch(rqstp, statp))
+			goto release_dropit;
+		if (*statp == rpc_garbage_args)
 			goto err_garbage;
-
-		*statp = procp->pc_func(rqstp);
-
-		/* Encode reply */
-		if (*statp == rpc_drop_reply ||
-		    test_bit(RQ_DROPME, &rqstp->rq_flags)) {
-			if (procp->pc_release)
-				procp->pc_release(rqstp);
-			goto dropit;
-		}
-		if (*statp == rpc_autherr_badcred) {
-			if (procp->pc_release)
-				procp->pc_release(rqstp);
-			goto err_bad_auth;
-		}
-		if (*statp == rpc_success && procp->pc_encode &&
-		    !procp->pc_encode(rqstp, resv->iov_base + resv->iov_len)) {
-			dprintk("svc: failed to encode reply\n");
-			/* serv->sv_stats->rpcsystemerr++; */
-			*statp = rpc_system_err;
-		}
+		auth_stat = svc_get_autherr(rqstp, statp);
+		if (auth_stat != rpc_auth_ok)
+			goto err_release_bad_auth;
 	} else {
 		dprintk("svc: calling dispatcher\n");
-		if (!versp->vs_dispatch(rqstp, statp)) {
-			/* Release reply info */
-			if (procp->pc_release)
-				procp->pc_release(rqstp);
-			goto dropit;
-		}
+		if (!process.dispatch(rqstp, statp))
+			goto release_dropit; /* Release reply info */
 	}
 
 	/* Check RPC status result */
@@ -1330,13 +1420,16 @@
 		goto close;
 	return 1;		/* Caller can now send it */
 
+release_dropit:
+	if (procp->pc_release)
+		procp->pc_release(rqstp);
  dropit:
 	svc_authorise(rqstp);	/* doesn't hurt to call this twice */
 	dprintk("svc: svc_process dropit\n");
 	return 0;
 
  close:
-	if (test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
+	if (rqstp->rq_xprt && test_bit(XPT_TEMP, &rqstp->rq_xprt->xpt_flags))
 		svc_close_xprt(rqstp->rq_xprt);
 	dprintk("svc: svc_process close\n");
 	return 0;
@@ -1354,6 +1447,9 @@
 	svc_putnl(resv, 2);
 	goto sendit;
 
+err_release_bad_auth:
+	if (procp->pc_release)
+		procp->pc_release(rqstp);
 err_bad_auth:
 	dprintk("svc: authentication failed (%d)\n", ntohl(auth_stat));
 	serv->sv_stats->rpcbadauth++;
@@ -1372,16 +1468,16 @@
 
 err_bad_vers:
 	svc_printk(rqstp, "unknown version (%d for prog %d, %s)\n",
-		       vers, prog, progp->pg_name);
+		       rqstp->rq_vers, rqstp->rq_prog, progp->pg_name);
 
 	serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, RPC_PROG_MISMATCH);
-	svc_putnl(resv, progp->pg_lovers);
-	svc_putnl(resv, progp->pg_hivers);
+	svc_putnl(resv, process.mismatch.lovers);
+	svc_putnl(resv, process.mismatch.hivers);
 	goto sendit;
 
 err_bad_proc:
-	svc_printk(rqstp, "unknown procedure (%d)\n", proc);
+	svc_printk(rqstp, "unknown procedure (%d)\n", rqstp->rq_proc);
 
 	serv->sv_stats->rpcbadfmt++;
 	svc_putnl(resv, RPC_PROC_UNAVAIL);
@@ -1431,6 +1527,10 @@
 		goto out_drop;
 	}
 
+	/* Reserve space for the record marker */
+	if (rqstp->rq_prot == IPPROTO_TCP)
+		svc_putnl(resv, 0);
+
 	/* Returns 1 for send, 0 for drop */
 	if (likely(svc_process_common(rqstp, argv, resv)))
 		return svc_send(rqstp);
@@ -1459,10 +1559,10 @@
 	dprintk("svc: %s(%p)\n", __func__, req);
 
 	/* Build the svc_rqst used by the common processing routine */
-	rqstp->rq_xprt = serv->sv_bc_xprt;
 	rqstp->rq_xid = req->rq_xid;
 	rqstp->rq_prot = req->rq_xprt->prot;
 	rqstp->rq_server = serv;
+	rqstp->rq_bc_net = req->rq_xprt->xprt_net;
 
 	rqstp->rq_addrlen = sizeof(req->rq_xprt->addr);
 	memcpy(&rqstp->rq_addr, &req->rq_xprt->addr, rqstp->rq_addrlen);
@@ -1495,13 +1595,13 @@
 	/* Parse and execute the bc call */
 	proc_error = svc_process_common(rqstp, argv, resv);
 
-	atomic_inc(&req->rq_xprt->bc_free_slots);
+	atomic_dec(&req->rq_xprt->bc_slot_count);
 	if (!proc_error) {
 		/* Processing error: drop the request */
 		xprt_free_bc_request(req);
-		return 0;
+		error = -EINVAL;
+		goto out;
 	}
-
 	/* Finally, send the reply synchronously */
 	memcpy(&req->rq_snd_buf, &rqstp->rq_res, sizeof(req->rq_snd_buf));
 	task = rpc_run_bc_task(req);