[release-branch.go1.7] syscall: use MNT_NOWAIT in TestGetfsstat

Fixes test failure when VMWare's shared folder filesystem is present.

MNT_NOWAIT is what the mount(8) command does.

Fixes #16937

Change-Id: Id436185f544b7069db46c8716d6a0bf580b31da0
Reviewed-on: https://go-review.googlesource.com/28550
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-on: https://go-review.googlesource.com/28650
Run-TryBot: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/syscall/syscall_bsd_test.go b/src/syscall/syscall_bsd_test.go
index c2ea089d50635ebecae7564d914e4de0c670d42d..f2bc3f5147084494d790ff7eb8841d36935a2373 100644 (file)
--- a/src/syscall/syscall_bsd_test.go
+++ b/src/syscall/syscall_bsd_test.go
@@ -7,28 +7,45 @@
 package syscall_test
 
 import (
+       "os/exec"
        "syscall"
        "testing"
 )
 
 const MNT_WAIT = 1
+const MNT_NOWAIT = 2
 
 func TestGetfsstat(t *testing.T) {
-       n, err := syscall.Getfsstat(nil, MNT_WAIT)
+       const flags = MNT_NOWAIT // see Issue 16937
+       n, err := syscall.Getfsstat(nil, flags)
+       t.Logf("Getfsstat(nil, %d) = (%v, %v)", flags, n, err)
        if err != nil {
                t.Fatal(err)
        }
 
        data := make([]syscall.Statfs_t, n)
-       n, err = syscall.Getfsstat(data, MNT_WAIT)
+       n2, err := syscall.Getfsstat(data, flags)
+       t.Logf("Getfsstat([]syscall.Statfs_t, %d) = (%v, %v)", flags, n2, err)
        if err != nil {
                t.Fatal(err)
        }
-
-       empty := syscall.Statfs_t{}
-       for _, stat := range data {
-               if stat == empty {
-                       t.Fatal("an empty Statfs_t struct was returned")
+       if n != n2 {
+               t.Errorf("Getfsstat(nil) = %d, but subsequent Getfsstat(slice) = %d", n, n2)
+       }
+       for i, stat := range data {
+               if stat == (syscall.Statfs_t{}) {
+                       t.Errorf("index %v is an empty Statfs_t struct", i)
+               }
+       }
+       if t.Failed() {
+               for i, stat := range data[:n2] {
+                       t.Logf("data[%v] = %+v", i, stat)
+               }
+               mount, err := exec.Command("mount").CombinedOutput()
+               if err != nil {
+                       t.Logf("mount: %v\n%s", err, mount)
+               } else {
+                       t.Logf("mount: %s", mount)
                }
        }
 }