pkg/mount: testing for linux sharedsubtree mounts

* shared
* shared/slave
* unbindable
* private

Signed-off-by: Vincent Batts <vbatts@redhat.com>

pkg/mount/sharedsubtree_linux_test.go

@@ -0,0 +1,331 @@
+// +build linux
+
+package mount
+
+import (
+	"os"
+	"path"
+	"syscall"
+	"testing"
+)
+
+// nothing is propogated in or out
+func TestSubtreePrivate(t *testing.T) {
+	tmp := path.Join(os.TempDir(), "mount-tests")
+	if err := os.MkdirAll(tmp, 0777); err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+
+	var (
+		sourceDir   = path.Join(tmp, "source")
+		targetDir   = path.Join(tmp, "target")
+		outside1Dir = path.Join(tmp, "outside1")
+		outside2Dir = path.Join(tmp, "outside2")
+
+		outside1Path      = path.Join(outside1Dir, "file.txt")
+		outside2Path      = path.Join(outside2Dir, "file.txt")
+		outside1CheckPath = path.Join(targetDir, "a", "file.txt")
+		outside2CheckPath = path.Join(sourceDir, "b", "file.txt")
+	)
+	if err := os.MkdirAll(path.Join(sourceDir, "a"), 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(path.Join(sourceDir, "b"), 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(targetDir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(outside1Dir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(outside2Dir, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := createFile(outside1Path); err != nil {
+		t.Fatal(err)
+	}
+	if err := createFile(outside2Path); err != nil {
+		t.Fatal(err)
+	}
+
+	// mount the shared directory to a target
+	if err := Mount(sourceDir, targetDir, "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(targetDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// next, make the target private
+	if err := MakePrivate(targetDir); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(targetDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// mount in an outside path to a mounted path inside the _source_
+	if err := Mount(outside1Dir, path.Join(sourceDir, "a"), "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(path.Join(sourceDir, "a")); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// check that this file _does_not_ show in the _target_
+	if _, err := os.Stat(outside1CheckPath); err != nil && !os.IsNotExist(err) {
+		t.Fatal(err)
+	} else if err == nil {
+		t.Fatalf("%q should not be visible, but is", outside1CheckPath)
+	}
+
+	// next mount outside2Dir into the _target_
+	if err := Mount(outside2Dir, path.Join(targetDir, "b"), "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(path.Join(targetDir, "b")); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// check that this file _does_not_ show in the _source_
+	if _, err := os.Stat(outside2CheckPath); err != nil && !os.IsNotExist(err) {
+		t.Fatal(err)
+	} else if err == nil {
+		t.Fatalf("%q should not be visible, but is", outside2CheckPath)
+	}
+}
+
+// Testing that when a target is a shared mount,
+// then child mounts propogate to the source
+func TestSubtreeShared(t *testing.T) {
+	tmp := path.Join(os.TempDir(), "mount-tests")
+	if err := os.MkdirAll(tmp, 0777); err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+
+	var (
+		sourceDir  = path.Join(tmp, "source")
+		targetDir  = path.Join(tmp, "target")
+		outsideDir = path.Join(tmp, "outside")
+
+		outsidePath     = path.Join(outsideDir, "file.txt")
+		sourceCheckPath = path.Join(sourceDir, "a", "file.txt")
+	)
+
+	if err := os.MkdirAll(path.Join(sourceDir, "a"), 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(targetDir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(outsideDir, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := createFile(outsidePath); err != nil {
+		t.Fatal(err)
+	}
+
+	// mount the source as shared
+	if err := MakeShared(sourceDir); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(sourceDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// mount the shared directory to a target
+	if err := Mount(sourceDir, targetDir, "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(targetDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// mount in an outside path to a mounted path inside the target
+	if err := Mount(outsideDir, path.Join(targetDir, "a"), "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(path.Join(targetDir, "a")); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// NOW, check that the file from the outside directory is avaible in the source directory
+	if _, err := os.Stat(sourceCheckPath); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// testing that mounts to a shared source show up in the slave target,
+// and that mounts into a slave target do _not_ show up in the shared source
+func TestSubtreeSharedSlave(t *testing.T) {
+	tmp := path.Join(os.TempDir(), "mount-tests")
+	if err := os.MkdirAll(tmp, 0777); err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+
+	var (
+		sourceDir   = path.Join(tmp, "source")
+		targetDir   = path.Join(tmp, "target")
+		outside1Dir = path.Join(tmp, "outside1")
+		outside2Dir = path.Join(tmp, "outside2")
+
+		outside1Path      = path.Join(outside1Dir, "file.txt")
+		outside2Path      = path.Join(outside2Dir, "file.txt")
+		outside1CheckPath = path.Join(targetDir, "a", "file.txt")
+		outside2CheckPath = path.Join(sourceDir, "b", "file.txt")
+	)
+	if err := os.MkdirAll(path.Join(sourceDir, "a"), 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(path.Join(sourceDir, "b"), 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(targetDir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(outside1Dir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(outside2Dir, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	if err := createFile(outside1Path); err != nil {
+		t.Fatal(err)
+	}
+	if err := createFile(outside2Path); err != nil {
+		t.Fatal(err)
+	}
+
+	// mount the source as shared
+	if err := MakeShared(sourceDir); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(sourceDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// mount the shared directory to a target
+	if err := Mount(sourceDir, targetDir, "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(targetDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// next, make the target slave
+	if err := MakeSlave(targetDir); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(targetDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// mount in an outside path to a mounted path inside the _source_
+	if err := Mount(outside1Dir, path.Join(sourceDir, "a"), "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(path.Join(sourceDir, "a")); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// check that this file _does_ show in the _target_
+	if _, err := os.Stat(outside1CheckPath); err != nil {
+		t.Fatal(err)
+	}
+
+	// next mount outside2Dir into the _target_
+	if err := Mount(outside2Dir, path.Join(targetDir, "b"), "none", "bind,rw"); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(path.Join(targetDir, "b")); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// check that this file _does_not_ show in the _source_
+	if _, err := os.Stat(outside2CheckPath); err != nil && !os.IsNotExist(err) {
+		t.Fatal(err)
+	} else if err == nil {
+		t.Fatalf("%q should not be visible, but is", outside2CheckPath)
+	}
+}
+
+func TestSubtreeUnbindable(t *testing.T) {
+	tmp := path.Join(os.TempDir(), "mount-tests")
+	if err := os.MkdirAll(tmp, 0777); err != nil {
+		t.Fatal(err)
+	}
+	defer os.RemoveAll(tmp)
+
+	var (
+		sourceDir = path.Join(tmp, "source")
+		targetDir = path.Join(tmp, "target")
+	)
+	if err := os.MkdirAll(sourceDir, 0777); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.MkdirAll(targetDir, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	// next, make the source unbindable
+	if err := MakeUnbindable(sourceDir); err != nil {
+		t.Fatal(err)
+	}
+	defer func() {
+		if err := Unmount(sourceDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+
+	// then attempt to mount it to target. It should fail
+	if err := Mount(sourceDir, targetDir, "none", "bind,rw"); err != nil && err != syscall.EINVAL {
+		t.Fatal(err)
+	} else if err == nil {
+		t.Fatalf("%q should not have been bindable")
+	}
+	defer func() {
+		if err := Unmount(targetDir); err != nil {
+			t.Fatal(err)
+		}
+	}()
+}
+
+func createFile(path string) error {
+	f, err := os.Create(path)
+	if err != nil {
+		return err
+	}
+	f.WriteString("hello world!")
+	return f.Close()
+}