fallback to origin IsLikelyNotMountPoint to avoid regression

Signed-off-by: j4ckstraw <[email protected]>

fix compile error

Kubernetes-commit: 47b1002bab47ffee51f2d25679cf9fa1932d5361

Author: j4ckstraw

mount_linux.go

@@ -29,6 +29,7 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/moby/sys/mountinfo"
@@ -403,21 +404,42 @@ func statx(file string) (unix.Statx_t, error) {
 	return stat, nil
 }
 
+func (mounter *Mounter) isLikelyNotMountPoint(file string) (bool, error) {
+	stat, err := os.Stat(file)
+	if err != nil {
+		return true, err
+	}
+	rootStat, err := os.Stat(filepath.Dir(strings.TrimSuffix(file, "/")))
+	if err != nil {
+		return true, err
+	}
+	// If the directory has a different device as parent, then it is a mountpoint.
+	if stat.Sys().(*syscall.Stat_t).Dev != rootStat.Sys().(*syscall.Stat_t).Dev {
+		return false, nil
+	}
+
+	return true, nil
+}
+
 // IsLikelyNotMountPoint determines if a directory is not a mountpoint.
-// If fast check failed, fall back to slow path. If the path is in fact
-// a bind mount from one part of a mount to another it will be detected.
-// It also can distinguish between mountpoints and symbolic links.
+// It is fast but not necessarily ALWAYS correct. If the path is in fact
+// a bind mount from one part of a mount to another it will not be detected.
+// It also can not distinguish between mountpoints and symbolic links.
 // mkdir /tmp/a /tmp/b; mount --bind /tmp/a /tmp/b; IsLikelyNotMountPoint("/tmp/b")
-// will return false. When in fact /tmp/b is a mount point.
+// will return true. When in fact /tmp/b is a mount point. If this situation
+// is of interest to you, don't use this function...
 func (mounter *Mounter) IsLikelyNotMountPoint(file string) (bool, error) {
 	var stat, rootStat unix.Statx_t
 	var err error
 
 	if stat, err = statx(file); err != nil {
 		if errors.Is(err, errStatxNotSupport) {
 			// not support statx, go slow path
-			mnt, mntErr := mounter.IsMountPoint(file)
-			return !mnt, mntErr
+			// mnt, mntErr := mounter.IsMountPoint(file)
+			// return !mnt, mntErr
+
+			// fall back to isLikelyNotMountPoint
+			return mounter.isLikelyNotMountPoint(file)
 		}
 
 		return false, err