tailscale: update tailfs file and package names (#11590)

This change updates the tailfs file and package names to their new
naming convention.

Updates #tailscale/corp#16827

Signed-off-by: Charlotte Brandhorst-Satzkorn <charlotte@tailscale.com>

drive/driveimpl/compositedav/stat_cache_test.go

@@ -0,0 +1,75 @@
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package compositedav
+
+import (
+	"bytes"
+	"testing"
+	"time"
+
+	"tailscale.com/tstest"
+)
+
+var (
+	val  = []byte("1")
+	file = "file"
+)
+
+func TestStatCacheNoTimeout(t *testing.T) {
+	// Make sure we don't leak goroutines
+	tstest.ResourceCheck(t)
+
+	c := &StatCache{TTL: 5 * time.Second}
+	defer c.stop()
+
+	// check get before set
+	fetched := c.get(file, 1)
+	if fetched != nil {
+		t.Errorf("got %q, want nil", fetched)
+	}
+
+	// set new stat
+	c.set(file, 1, val)
+	fetched = c.get(file, 1)
+	if !bytes.Equal(fetched, val) {
+		t.Errorf("got %q, want %q", fetched, val)
+	}
+
+	// fetch stat again, should still be cached
+	fetched = c.get(file, 1)
+	if !bytes.Equal(fetched, val) {
+		t.Errorf("got %q, want %q", fetched, val)
+	}
+}
+
+func TestStatCacheTimeout(t *testing.T) {
+	// Make sure we don't leak goroutines
+	tstest.ResourceCheck(t)
+
+	c := &StatCache{TTL: 250 * time.Millisecond}
+	defer c.stop()
+
+	// set new stat
+	c.set(file, 1, val)
+	fetched := c.get(file, 1)
+	if !bytes.Equal(fetched, val) {
+		t.Errorf("got %q, want %q", fetched, val)
+	}
+
+	// wait for cache to expire and refetch stat, should be empty now
+	time.Sleep(c.TTL * 2)
+
+	fetched = c.get(file, 1)
+	if fetched != nil {
+		t.Errorf("invalidate should have cleared cached value")
+	}
+
+	c.set(file, 1, val)
+	// invalidate the cache and make sure nothing is returned
+	c.invalidate()
+	fetched = c.get(file, 1)
+	if fetched != nil {
+		t.Errorf("invalidate should have cleared cached value")
+	}
+}