Test with stat that doesn't hang.

Signed-off-by: Thomas Hallgren <thomas@datawire.io>

pkg/fs/fuse.go

@@ -29,15 +29,17 @@ func NewHost(fsh fuse.FileSystemInterface, mountPoint string) *FuseHost {
 
 // Start will mount the filesystem on the mountPoint passed to NewHost.
 func (fh *FuseHost) Start(ctx context.Context, startTimeout time.Duration) error {
-	ctx, cancel := context.WithCancel(ctx)
-	fh.cancel = cancel
+	ctx, fh.cancel = context.WithCancel(ctx)
 
 	opts := []string{
 		"-o", "default_permissions",
 		"-o", "auto_cache",
 		"-o", "sync_read",
 		"-o", "allow_root",
 	}
+	if logrus.GetLevel() >= logrus.DebugLevel {
+		opts = append(opts, "-o", "debug")
+	}
 	if runtime.GOOS == "windows" {
 		// WinFsp requires this to create files with the same
 		// user as the one that starts the FUSE mount
@@ -47,9 +49,6 @@ func (fh *FuseHost) Start(ctx context.Context, startTimeout time.Duration) error
 	startCtx, startCancel := context.WithTimeout(ctx, startTimeout)
 	defer startCancel()
 	go fh.detectFuseStarted(startCtx, started)
-	if logrus.GetLevel() >= logrus.DebugLevel {
-		opts = append(opts, "-o", "debug")
-	}
 
 	mCh := make(chan bool, 1)
 	fh.wg.Add(1)

pkg/fs/fuse_started_unix.go

@@ -13,9 +13,8 @@ import (
 )
 
 func (fh *FuseHost) detectFuseStarted(ctx context.Context, started chan error) {
-	time.Sleep(100 * time.Millisecond)
-	var st unix.Stat_t
-	if err := unix.Stat(fh.mountPoint, &st); err != nil {
+	st, err := statWithTimeout(ctx, fh.mountPoint, 10*time.Millisecond)
+	if err != nil {
 		select {
 		case started <- fmt.Errorf("unable to stat mount point %q: %v", fh.mountPoint, err):
 		default:
@@ -39,8 +38,7 @@ func (fh *FuseHost) detectFuseStarted(ctx context.Context, started chan error) {
 			}
 			return
 		case <-ticker.C:
-			var mountSt unix.Stat_t
-			if err := unix.Stat(fh.mountPoint, &mountSt); err != nil {
+			if mountSt, err := statWithTimeout(ctx, fh.mountPoint, 20*time.Millisecond); err != nil {
 				// we don't consider a failure to stat an error here, just a cause for a retry.
 				logrus.Debugf("unable to stat mount point %q: %v", fh.mountPoint, err)
 			} else {
@@ -51,3 +49,24 @@ func (fh *FuseHost) detectFuseStarted(ctx context.Context, started chan error) {
 		}
 	}
 }
+
+// statWithTimeout performs a normal unix.Stat but will not allow that it hangs for
+// more than the given timeout.
+func statWithTimeout(ctx context.Context, path string, timeout time.Duration) (*unix.Stat_t, error) {
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	defer cancel()
+	errCh := make(chan error, 1)
+	mountSt := new(unix.Stat_t)
+	go func() {
+		errCh <- unix.Stat(path, mountSt)
+	}()
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	case err := <-errCh:
+		if err != nil {
+			return nil, err
+		}
+		return mountSt, nil
+	}
+}