reverse mode: implement -one-file-system

Fixes https://github.com/rfjakob/gocryptfs/issues/475

1 files changed, 77 insertions, 0 deletions

diff --git a/tests/reverse/one_file_system_test.go b/tests/reverse/one_file_system_test.go
new file mode 100644
index 0000000..5d8b76b
--- /dev/null
+++ b/tests/reverse/one_file_system_test.go
@@ -0,0 +1,77 @@
+package reverse
+
+import (
+	"io/ioutil"
+	"net/url"
+	"os"
+	"runtime"
+	"syscall"
+	"testing"
+
+	"github.com/rfjakob/gocryptfs/tests/test_helpers"
+)
+
+func doTestOneFileSystem(t *testing.T, plaintextnames bool) {
+	// Let's not explode with "TempDir: pattern contains path separator"
+	myEscapedName := url.PathEscape(t.Name())
+	mnt, err := ioutil.TempDir(test_helpers.TmpDir, myEscapedName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	cliArgs := []string{"-reverse", "-zerokey", "-one-file-system"}
+	if plaintextnames {
+		cliArgs = append(cliArgs, "-plaintextnames")
+	}
+	test_helpers.MountOrFatal(t, "/", mnt, cliArgs...)
+	defer test_helpers.UnmountErr(mnt)
+
+	// Copied from inomap
+	const maxPassthruIno = 1<<48 - 1
+
+	entries, err := os.ReadDir(mnt)
+	if err != nil {
+		t.Fatal(err)
+	}
+	mountpoints := []string{}
+	for _, e := range entries {
+		i, err := e.Info()
+		if err != nil {
+			continue
+		}
+		if !e.IsDir() {
+			// We are only interested in directories
+			continue
+		}
+		st := i.Sys().(*syscall.Stat_t)
+		// The inode numbers of files with a different device number are remapped
+		// to something above maxPassthruIno
+		if st.Ino > maxPassthruIno {
+			mountpoints = append(mountpoints, e.Name())
+		}
+	}
+	if len(mountpoints) == 0 {
+		t.Skip("no mountpoints found, nothing to test")
+	}
+	for _, m := range mountpoints {
+		e, err := os.ReadDir(mnt + "/" + m)
+		if err != nil {
+			t.Error(err)
+		}
+		expected := 1
+		if plaintextnames {
+			expected = 0
+		}
+		if len(e) != expected {
+			t.Errorf("mountpoint %q does not look empty: %v", m, e)
+		}
+	}
+	t.Logf("tested %d mountpoints: %v", len(mountpoints), mountpoints)
+}
+
+func TestOneFileSystem(t *testing.T) {
+	if runtime.GOOS != "linux" {
+		t.Skip("only works on linux")
+	}
+	t.Run("normal", func(t *testing.T) { doTestOneFileSystem(t, false) })
+	t.Run("plaintextnames", func(t *testing.T) { doTestOneFileSystem(t, true) })
+}