mountinfo: unify mountedBy checks

kolyshkin · kolyshkin · commit 03cca996870e · 2021-12-02T19:27:17.000-08:00
Instead of copy/pasting the code to check individual mountedBy*
implementations, add a list and a loop to check them.

The only special thing is, we have to check if the name of the function
being tested is "mountedByStat", to skip erroring out on bind mounts.
Otherwise the code is the same.

Signed-off-by: Kir Kolyshkin &lt;kolyshkin@gmail.com&gt;
diff --git a/mountinfo/mounted_linux_test.go b/mountinfo/mounted_linux_test.go
@@ -5,6 +5,9 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"reflect"
+	"runtime"
+	"strings"
 	"testing"
 
 	"golang.org/x/sys/unix"
@@ -276,8 +279,14 @@ func tryOpenat2() error {
 }
 
 func TestMountedBy(t *testing.T) {
-	openat2Supported := tryOpenat2() == nil
 	checked := false
+
+	// List of individual implementations to check.
+	toCheck := []func(string) (bool, error){mountedByMountinfo, mountedByStat}
+	if tryOpenat2() == nil {
+		toCheck = append(toCheck, mountedByOpenat2)
+	}
+
 	for _, tc := range testMounts {
 		tc := tc
 		t.Run(tc.desc, func(t *testing.T) {
@@ -316,45 +325,29 @@ func TestMountedBy(t *testing.T) {
 				t.Fatalf("normalizePath: %v", err)
 			}
 
-			mounted, err = mountedByMountinfo(m)
-			if err != nil {
-				t.Errorf("mountedByMountinfo error: %v", err)
-				// Check false is returned in error case.
-				if mounted != false {
-					t.Errorf("MountedByMountinfo: expected false on error, got %v", mounted)
-				}
-			} else if mounted != exp {
-				t.Errorf("mountedByMountinfo: expected %v, got %v", exp, mounted)
-			}
-			checked = true
-
-			mounted, err = mountedByStat(m)
-			if err != nil {
-				t.Errorf("mountedByStat error: %v", err)
-				// Check false is returned in error case.
-				if mounted != false {
-					t.Errorf("MountedByStat: expected false on error, got %v", mounted)
-				}
-			} else if mounted != exp && !tc.isBind { // mountedByStat can not detect bind mounts
-				t.Errorf("mountedByStat: expected %v, got %v", exp, mounted)
-			}
-
-			if !openat2Supported {
-				return
-			}
-			mounted, err = mountedByOpenat2(m)
-			if err != nil {
-				t.Errorf("mountedByOpenat2 error: %v", err)
-				// Check false is returned in error case.
-				if mounted != false {
-					t.Errorf("MountedByOpenat2: expected false on error, got %v", mounted)
+			for _, fn := range toCheck {
+				// Figure out function name.
+				name := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
+
+				mounted, err = fn(m)
+				if err != nil {
+					t.Errorf("%s: %v", name, err)
+					// Check false is returned in error case.
+					if mounted != false {
+						t.Errorf("%s: expected false on error, got %v", name, mounted)
+					}
+				} else if mounted != exp {
+					if tc.isBind && strings.HasSuffix(name, "mountedByStat") {
+						// mountedByStat can not detect bind mounts.
+					} else {
+						t.Errorf("%s: expected %v, got %v", name, exp, mounted)
+					}
 				}
-			} else if mounted != exp {
-				t.Errorf("mountedByOpenat2: expected %v, got %v", exp, mounted)
+				checked = true
 			}
 		})
-
 	}
+
 	if !checked {
 		t.Skip("no mounts to check")
 	}
