8173910: (fs) java/nio/file/FileSystem/Basic.java should conditionally check FileStores

Summary: On Unix platforms, spawn a 'df' process and skip FileStore check if it hangs
Reviewed-by: alanb

test/java/nio/file/FileSystem/Basic.java

 /*
- * Copyright (c) 2008, 2012, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,9 +27,19 @@
  * @library ..
  */
 
-import java.nio.file.*;
-import java.nio.file.attribute.*;
+import java.io.File;
 import java.io.IOException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.Files;
+import java.nio.file.FileStore;
+import java.nio.file.FileSystem;
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.ProviderNotFoundException;
+import java.util.HashMap;
+import java.util.concurrent.TimeUnit;
 
 /**
  * Simple santity checks for java.nio.file.FileSystem
@@ -41,6 +51,44 @@ public class Basic {
             throw new RuntimeException(msg);
     }
 
+    static void checkFileStores(String os, FileSystem fs) throws IOException {
+        boolean checkFileStores = true;
+        if (!os.equals("Windows")) {
+            // try to check whether 'df' hangs
+            System.out.println("\n--- Begin df output ---");
+            System.out.flush();
+            Process proc = new ProcessBuilder("df").inheritIO().start();
+            try {
+                proc.waitFor(90, TimeUnit.SECONDS);
+            } catch (InterruptedException ignored) {
+            }
+            System.out.println("--- End df output ---\n");
+            System.out.flush();
+            try {
+                int exitValue = proc.exitValue();
+                if (exitValue != 0) {
+                    System.err.printf("df process exited with %d != 0%n",
+                        exitValue);
+                    checkFileStores = false;
+                }
+            } catch (IllegalThreadStateException ignored) {
+                System.err.println("df command apparently hung");
+                checkFileStores = false;
+            }
+        }
+
+        // sanity check method
+        if (checkFileStores) {
+            System.out.println("\n--- Begin FileStores ---");
+            for (FileStore store: fs.getFileStores()) {
+                System.out.println(store);
+            }
+            System.out.println("--- EndFileStores ---\n");
+        } else {
+            System.err.println("Skipping FileStore check due to df failure");
+        }
+    }
+
     static void checkSupported(FileSystem fs, String... views) {
         for (String view: views) {
             check(fs.supportedFileAttributeViews().contains(view),
@@ -48,7 +96,9 @@ public class Basic {
         }
     }
 
-    public static void main(String[] args) throws IOException {
+    public static void main(String[] args)
+        throws IOException, URISyntaxException {
+        String os = System.getProperty("os.name");
         FileSystem fs = FileSystems.getDefault();
 
         // close should throw UOE
@@ -63,15 +113,11 @@ public class Basic {
         check(fs.provider().getScheme().equals("file"),
             "should use 'file' scheme");
 
-        // santity check method - need to re-visit this in future as I/O errors
-        // are possible
-        for (FileStore store: fs.getFileStores()) {
-            System.out.println(store);
-        }
+        // sanity check FileStores
+        checkFileStores(os, fs);
 
         // sanity check supportedFileAttributeViews
         checkSupported(fs, "basic");
-        String os = System.getProperty("os.name");
         if (os.equals("SunOS"))
             checkSupported(fs, "posix", "unix", "owner", "acl", "user");
         if (os.equals("Linux"))