RPC,NFSv2/v3/v4: Ensure that xprt_create_proto() and rpc_create_client() return

     full error codes. Should allow the "mount" program to print more useful error
     diagnostics.

fs/lockd/host.c

@@ -188,14 +188,14 @@ nlm_bind_host(struct nlm_host *host)
 		}
 	} else {
 		xprt = xprt_create_proto(host->h_proto, &host->h_addr, NULL);
-		if (xprt == NULL)
+		if (IS_ERR(xprt))
 			goto forgetit;
 
 		xprt_set_timeout(&xprt->timeout, 5, nlmsvc_timeout);
 
 		clnt = rpc_create_client(xprt, host->h_name, &nlm_program,
 					host->h_version, host->h_authflavor);
-		if (clnt == NULL) {
+		if (IS_ERR(clnt)) {
 			xprt_destroy(xprt);
 			goto forgetit;
 		}

fs/lockd/mon.c

@@ -36,10 +36,11 @@ nsm_mon_unmon(struct nlm_host *host, u32 proc, struct nsm_res *res)
 	int		status;
 	struct nsm_args	args;
 
-	status = -EACCES;
 	clnt = nsm_create();
-	if (!clnt)
+	if (IS_ERR(clnt)) {
+		status = PTR_ERR(clnt);
 		goto out;
+	}
 
 	args.addr = host->h_addr.sin_addr.s_addr;
 	args.proto= (host->h_proto<<1) | host->h_server;
@@ -104,7 +105,7 @@ static struct rpc_clnt *
 nsm_create(void)
 {
 	struct rpc_xprt		*xprt;
-	struct rpc_clnt		*clnt = NULL;
+	struct rpc_clnt		*clnt;
 	struct sockaddr_in	sin;
 
 	sin.sin_family = AF_INET;
@@ -112,24 +113,23 @@ nsm_create(void)
 	sin.sin_port = 0;
 
 	xprt = xprt_create_proto(IPPROTO_UDP, &sin, NULL);
-	if (!xprt)
-		goto out;
+	if (IS_ERR(xprt))
+		return (struct rpc_clnt *)xprt;
 
 	clnt = rpc_create_client(xprt, "localhost",
 				&nsm_program, SM_VERSION,
 				RPC_AUTH_NULL);
-	if (!clnt)
+	if (IS_ERR(clnt))
 		goto out_destroy;
 	clnt->cl_softrtry = 1;
 	clnt->cl_chatty   = 1;
 	clnt->cl_oneshot  = 1;
 	xprt->resvport = 1;	/* NSM requires a reserved port */
-out:
 	return clnt;
 
 out_destroy:
 	xprt_destroy(xprt);
-	goto out;
+	return clnt;
 }
 
 /*

fs/nfs/inode.c

@@ -371,13 +371,13 @@ nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
 	/* create transport and client */
 	xprt = xprt_create_proto(tcp ? IPPROTO_TCP : IPPROTO_UDP,
 				 &server->addr, &timeparms);
-	if (xprt == NULL) {
+	if (IS_ERR(xprt)) {
 		printk(KERN_WARNING "NFS: cannot create RPC transport.\n");
-		goto out_fail;
+		return (struct rpc_clnt *)xprt;
 	}
 	clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
 				 server->rpc_ops->version, data->pseudoflavor);
-	if (clnt == NULL) {
+	if (IS_ERR(clnt)) {
 		printk(KERN_WARNING "NFS: cannot create RPC client.\n");
 		goto out_fail;
 	}
@@ -390,9 +390,8 @@ nfs_create_client(struct nfs_server *server, const struct nfs_mount_data *data)
 	return clnt;
 
 out_fail:
-	if (xprt)
 	xprt_destroy(xprt);
-	return NULL;
+	return clnt;
 }
 
 /*
@@ -1492,17 +1491,19 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
 	down_write(&clp->cl_sem);
 	if (clp->cl_rpcclient == NULL) {
 		xprt = xprt_create_proto(proto, &server->addr, &timeparms);
-		if (xprt == NULL) {
+		if (IS_ERR(xprt)) {
 			up_write(&clp->cl_sem);
 			printk(KERN_WARNING "NFS: cannot create RPC transport.\n");
+			err = PTR_ERR(xprt);
 			goto out_fail;
 		}
 		clnt = rpc_create_client(xprt, server->hostname, &nfs_program,
 				server->rpc_ops->version, authflavour);
-		if (clnt == NULL) {
+		if (IS_ERR(clnt)) {
 			up_write(&clp->cl_sem);
 			printk(KERN_WARNING "NFS: cannot create RPC client.\n");
 			xprt_destroy(xprt);
+			err = PTR_ERR(clnt);
 			goto out_fail;
 		}
 		clnt->cl_chatty   = 1;
@@ -1515,14 +1516,17 @@ static int nfs4_fill_super(struct super_block *sb, struct nfs4_mount_data *data,
 		clear_bit(NFS4CLNT_OK, &clp->cl_state);
 	list_add_tail(&server->nfs4_siblings, &clp->cl_superblocks);
 	clnt = rpc_clone_client(clp->cl_rpcclient);
+	if (!IS_ERR(clnt))
 			server->nfs4_state = clp;
 	up_write(&clp->cl_sem);
 	clp = NULL;
 
-	if (clnt == NULL) {
+	if (IS_ERR(clnt)) {
 		printk(KERN_WARNING "NFS: cannot create RPC client.\n");
+		err = PTR_ERR(clnt);
 		goto out_remove_list;
 	}
+	err = -ENOMEM;
 	if (server->nfs4_state->cl_idmap == NULL) {
 		printk(KERN_WARNING "NFS: failed to create idmapper.\n");
 		goto out_shutdown;

fs/nfs/mount_clnt.c

@@ -57,8 +57,9 @@ nfsroot_mount(struct sockaddr_in *addr, char *path, struct nfs_fh *fh,
 			(unsigned)ntohl(addr->sin_addr.s_addr), path);
 
 	sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(addr->sin_addr.s_addr));
-	if (!(mnt_clnt = mnt_create(hostname, addr, version, protocol)))
-		return -EACCES;
+	mnt_clnt = mnt_create(hostname, addr, version, protocol);
+	if (IS_ERR(mnt_clnt))
+		return PTR_ERR(mnt_clnt);
 
 	call = (version == NFS_MNT3_VERSION) ? MOUNTPROC3_MNT : MNTPROC_MNT;
 	status = rpc_call(mnt_clnt, call, path, &result, 0);
@@ -72,13 +73,14 @@ mnt_create(char *hostname, struct sockaddr_in *srvaddr, int version,
 	struct rpc_xprt	*xprt;
 	struct rpc_clnt	*clnt;
 
-	if (!(xprt = xprt_create_proto(protocol, srvaddr, NULL)))
-		return NULL;
+	xprt = xprt_create_proto(protocol, srvaddr, NULL);
+	if (IS_ERR(xprt))
+		return (struct rpc_clnt *)xprt;
 
 	clnt = rpc_create_client(xprt, hostname,
 				&mnt_program, version,
-				RPC_AUTH_NULL);
-	if (!clnt) {
+				RPC_AUTH_UNIX);
+	if (IS_ERR(clnt)) {
 		xprt_destroy(xprt);
 	} else {
 		clnt->cl_softrtry = 1;

net/sunrpc/clnt.c

@@ -102,19 +102,22 @@ rpc_create_client(struct rpc_xprt *xprt, char *servname,
 {
 	struct rpc_version	*version;
 	struct rpc_clnt		*clnt = NULL;
+	int err;
 	int len;
 
 	dprintk("RPC: creating %s client for %s (xprt %p)\n",
 		program->name, servname, xprt);
 
+	err = -EINVAL;
 	if (!xprt)
-		goto out;
+		goto out_err;
 	if (vers >= program->nrvers || !(version = program->version[vers]))
-		goto out;
+		goto out_err;
 
+	err = -ENOMEM;
 	clnt = (struct rpc_clnt *) kmalloc(sizeof(*clnt), GFP_KERNEL);
 	if (!clnt)
-		goto out_no_clnt;
+		goto out_err;
 	memset(clnt, 0, sizeof(*clnt));
 	atomic_set(&clnt->cl_users, 0);
 	atomic_set(&clnt->cl_count, 1);
@@ -149,9 +152,11 @@ rpc_create_client(struct rpc_xprt *xprt, char *servname,
 	clnt->cl_rtt = &clnt->cl_rtt_default;
 	rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
 
-	if (rpc_setup_pipedir(clnt, program->pipe_dir_name) < 0)
+	err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
+	if (err < 0)
 		goto out_no_path;
 
+	err = -ENOMEM;
 	if (!rpcauth_create(flavor, clnt)) {
 		printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
 				flavor);
@@ -163,20 +168,16 @@ rpc_create_client(struct rpc_xprt *xprt, char *servname,
 	if (clnt->cl_nodelen > UNX_MAXNODENAME)
 		clnt->cl_nodelen = UNX_MAXNODENAME;
 	memcpy(clnt->cl_nodename, system_utsname.nodename, clnt->cl_nodelen);
-out:
 	return clnt;
 
-out_no_clnt:
-	printk(KERN_INFO "RPC: out of memory in rpc_create_client\n");
-	goto out;
 out_no_auth:
 	rpc_rmdir(clnt->cl_pathname);
 out_no_path:
 	if (clnt->cl_server != clnt->cl_inline_name)
 		kfree(clnt->cl_server);
 	kfree(clnt);
-	clnt = NULL;
-	goto out;
+out_err:
+	return ERR_PTR(err);
 }
 
 /*
@@ -198,11 +199,10 @@ rpc_clone_client(struct rpc_clnt *clnt)
 	atomic_inc(&new->cl_parent->cl_count);
 	if (new->cl_auth)
 		atomic_inc(&new->cl_auth->au_count);
-out:
 	return new;
 out_no_clnt:
 	printk(KERN_INFO "RPC: out of memory in %s\n", __FUNCTION__);
-	goto out;
+	return ERR_PTR(-ENOMEM);
 }
 
 /*

net/sunrpc/pmap_clnt.c

@@ -65,9 +65,11 @@ rpc_getport(struct rpc_task *task, struct rpc_clnt *clnt)
 	map->pm_binding = 1;
 	spin_unlock(&pmap_lock);
 
-	task->tk_status = -EACCES; /* why set this? returns -EIO below */
-	if (!(pmap_clnt = pmap_create(clnt->cl_server, sap, map->pm_prot)))
+	pmap_clnt = pmap_create(clnt->cl_server, sap, map->pm_prot);
+	if (IS_ERR(pmap_clnt)) {
+		task->tk_status = PTR_ERR(pmap_clnt);
 		goto bailout;
+	}
 	task->tk_status = 0;
 
 	/*
@@ -110,8 +112,9 @@ rpc_getport_external(struct sockaddr_in *sin, __u32 prog, __u32 vers, int prot)
 			NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
 
 	sprintf(hostname, "%u.%u.%u.%u", NIPQUAD(sin->sin_addr.s_addr));
-	if (!(pmap_clnt = pmap_create(hostname, sin, prot)))
-		return -EACCES;
+	pmap_clnt = pmap_create(hostname, sin, prot);
+	if (IS_ERR(pmap_clnt))
+		return PTR_ERR(pmap_clnt);
 
 	/* Setup the call info struct */
 	status = rpc_call(pmap_clnt, PMAP_GETPORT, &map, &map.pm_port, 0);
@@ -161,16 +164,18 @@ rpc_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
 	struct sockaddr_in	sin;
 	struct rpc_portmap	map;
 	struct rpc_clnt		*pmap_clnt;
-	unsigned int		error = 0;
+	int error = 0;
 
 	dprintk("RPC: registering (%d, %d, %d, %d) with portmapper.\n",
 			prog, vers, prot, port);
 
 	sin.sin_family = AF_INET;
 	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-	if (!(pmap_clnt = pmap_create("localhost", &sin, IPPROTO_UDP))) {
-		dprintk("RPC: couldn't create pmap client\n");
-		return -EACCES;
+	pmap_clnt = pmap_create("localhost", &sin, IPPROTO_UDP);
+	if (IS_ERR(pmap_clnt)) {
+		error = PTR_ERR(pmap_clnt);
+		dprintk("RPC: couldn't create pmap client. Error = %d\n", error);
+		return error;
 	}
 
 	map.pm_prog = prog;
@@ -199,15 +204,16 @@ pmap_create(char *hostname, struct sockaddr_in *srvaddr, int proto)
 	struct rpc_clnt	*clnt;
 
 	/* printk("pmap: create xprt\n"); */
-	if (!(xprt = xprt_create_proto(proto, srvaddr, NULL)))
-		return NULL;
+	xprt = xprt_create_proto(proto, srvaddr, NULL);
+	if (IS_ERR(xprt))
+		return (struct rpc_clnt *)xprt;
 	xprt->addr.sin_port = htons(RPC_PMAP_PORT);
 
 	/* printk("pmap: create clnt\n"); */
 	clnt = rpc_create_client(xprt, hostname,
 				&pmap_program, RPC_PMAP_VERSION,
 				RPC_AUTH_NULL);
-	if (!clnt) {
+	if (IS_ERR(clnt)) {
 		xprt_destroy(xprt);
 	} else {
 		clnt->cl_softrtry = 1;

net/sunrpc/xprt.c

@@ -1421,7 +1421,7 @@ xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to)
 				proto == IPPROTO_UDP? "UDP" : "TCP");
 
 	if ((xprt = kmalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 	memset(xprt, 0, sizeof(*xprt)); /* Nnnngh! */
 
 	xprt->addr = *ap;
@@ -1597,16 +1597,11 @@ xprt_create_proto(int proto, struct sockaddr_in *sap, struct rpc_timeout *to)
 	struct rpc_xprt	*xprt;
 
 	xprt = xprt_setup(proto, sap, to);
-	if (!xprt)
-		goto out_bad;
-
+	if (IS_ERR(xprt))
+		dprintk("RPC:      xprt_create_proto failed\n");
+	else
 		dprintk("RPC:      xprt_create_proto created xprt %p\n", xprt);
 	return xprt;
- out_bad:
-	dprintk("RPC:      xprt_create_proto failed\n");
-	if (xprt)
-		kfree(xprt);
-	return NULL;
 }
 
 /*