sunrpc: Use userns friendly constants.

Instead of (uid_t)0 use GLOBAL_ROOT_UID.
Instead of (gid_t)0 use GLOBAL_ROOT_GID.
Instead of (uid_t)-1 use INVALID_UID
Instead of (gid_t)-1 use INVALID_GID.
Instead of NOGROUP use INVALID_GID.

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

net/sunrpc/auth.c

@@ -519,8 +519,8 @@ rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags)
 {
 	struct rpc_auth *auth = task->tk_client->cl_auth;
 	struct auth_cred acred = {
-		.uid = 0,
-		.gid = 0,
+		.uid = GLOBAL_ROOT_UID,
+		.gid = GLOBAL_ROOT_GID,
 	};
 
 	dprintk("RPC: %5u looking up %s cred\n",

net/sunrpc/auth_generic.c

@@ -18,8 +18,8 @@
 # define RPCDBG_FACILITY	RPCDBG_AUTH
 #endif
 
-#define RPC_MACHINE_CRED_USERID		((uid_t)0)
-#define RPC_MACHINE_CRED_GROUPID	((gid_t)0)
+#define RPC_MACHINE_CRED_USERID		GLOBAL_ROOT_UID
+#define RPC_MACHINE_CRED_GROUPID	GLOBAL_ROOT_GID
 
 struct generic_cred {
 	struct rpc_cred gc_base;

net/sunrpc/auth_unix.c

@@ -85,7 +85,7 @@ unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 		cred->uc_gids[i] = gid;
 	}
 	if (i < NFS_NGROUPS)
-		cred->uc_gids[i] = NOGROUP;
+		cred->uc_gids[i] = INVALID_GID;
 
 	return &cred->uc_base;
 }
@@ -137,7 +137,7 @@ unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
 			return 0;
 	}
 	if (groups < NFS_NGROUPS &&
-	    cred->uc_gids[groups] != NOGROUP)
+	    cred->uc_gids[groups] != INVALID_GID)
 		return 0;
 	return 1;
 }
@@ -166,7 +166,7 @@ unx_marshal(struct rpc_task *task, __be32 *p)
 	*p++ = htonl((u32) cred->uc_uid);
 	*p++ = htonl((u32) cred->uc_gid);
 	hold = p++;
-	for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
+	for (i = 0; i < 16 && cred->uc_gids[i] != INVALID_GID; i++)
 		*p++ = htonl((u32) cred->uc_gids[i]);
 	*hold = htonl(p - hold - 1);		/* gid array length */
 	*base = htonl((p - base - 1) << 2);	/* cred length */

net/sunrpc/svcauth_unix.c

@@ -750,8 +750,8 @@ svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
 	}
 
 	/* Signal that mapping to nobody uid/gid is required */
-	cred->cr_uid = (uid_t) -1;
-	cred->cr_gid = (gid_t) -1;
+	cred->cr_uid = INVALID_UID;
+	cred->cr_gid = INVALID_GID;
 	cred->cr_group_info = groups_alloc(0);
 	if (cred->cr_group_info == NULL)
 		return SVC_CLOSE; /* kmalloc failure - client must retry */