nfs4: Make Inode::Access() use cached attributes

src/add-ons/kernel/file_systems/nfs4/Inode.cpp

@@ -445,6 +445,32 @@ Inode::ReadLink(void* buffer, size_t* length)
 status_t
 Inode::Access(int mode)
 {
+	int acc = 0;
+
+	if (fFileSystem->IsAttrSupported(FATTR4_MODE)) {
+		status_t result = _UpdateAttrCache();
+		if (result != B_OK)
+			return result;
+
+		// Root squashing and owner mapping problems may make this function
+		// return false values. However, since due to race condition it can
+		// not be used for anything critical, it is not a serius problem.
+
+		mode_t nodeMode = fAttrCache.st_mode;
+		uint8 userMode = (nodeMode & S_IRWXU) >> 6;
+		uint8 groupMode = (nodeMode & S_IRWXG) >> 3;
+		uint8 otherMode = (nodeMode & S_IRWXO);
+
+		uid_t uid = geteuid();
+		if (uid == 0)
+			acc = userMode | groupMode | otherMode | R_OK | W_OK;
+		else if (uid == fAttrCache.st_uid)
+			acc = userMode;
+		else if (getegid() == fAttrCache.st_gid)
+			acc = groupMode;
+		else
+			acc = otherMode;
+	} else {
 		do {
 			RPC::Server* serv = fFileSystem->Server();
 			Request request(serv);
@@ -469,7 +495,6 @@ Inode::Access(int mode)
 			if (result != B_OK)
 				return result;
 
-		int acc = 0;
 			if ((allowed & ACCESS4_READ) != 0)
 				acc |= R_OK;
 
@@ -482,11 +507,14 @@ Inode::Access(int mode)
 			if ((allowed & ACCESS4_MODIFY) != 0)
 				acc |= W_OK;
 
+			break;
+		} while (true);
+	}
+
 	if ((mode & acc) != mode)
 		return B_NOT_ALLOWED;
 
 	return B_OK;
-	} while (true);
 }