RFC: Fail on unmount/rmdir in overlay.Driver.Put

instead of only logging a debug-level failure. We are seeing layers being mounted while our metadata claims that they are unmounted, and this seems to be a way how that could happen without leaving a visible trace. It's unclear to me why this silently succeeds; this behavior is very long-standing. Signed-off-by: Miloslav Trmač <[email protected]>
containers · May 22, 2023 · da0df59 · da0df59
1 parent 9e425af
commit da0df59
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/drivers/overlay/overlay.go b/drivers/overlay/overlay.go
@@ -1770,11 +1770,13 @@ func (d *Driver) Put(id string) error {
 	if !unmounted {
 		if err := unix.Unmount(mountpoint, unix.MNT_DETACH); err != nil && !os.IsNotExist(err) {
 			logrus.Debugf("Failed to unmount %s overlay: %s - %v", id, mountpoint, err)
+			return fmt.Errorf("unmounting %q: %w", mountpoint, err)
 		}
 	}
 
 	if err := unix.Rmdir(mountpoint); err != nil && !os.IsNotExist(err) {
 		logrus.Debugf("Failed to remove mountpoint %s overlay: %s - %v", id, mountpoint, err)
+		return fmt.Errorf("removing mount point %q: %w", mountpoint, err)
 	}
 
 	return nil