Ensure volumes can be removed when they fail to unmount

Also, ensure that we don't try to mount them without root - it
appears that it can somehow not error and report that mount was
successful when it clearly did not succeed, which can induce this
case.

We reuse the `--force` flag to indicate that a volume should be
removed even after unmount errors. It seems fairly natural to
expect that --force will remove a volume that is otherwise
presenting problems.

Finally, ignore EINVAL on unmount - if the mount point no longer
exists our job is done.

Fixes: #4247
Fixes: #4248

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

1 files changed, 8 insertions, 1 deletions

diff --git a/libpod/runtime_volume_linux.go b/libpod/runtime_volume_linux.go
index 9df93faf3..ba4fff4be 100644
--- a/libpod/runtime_volume_linux.go
+++ b/libpod/runtime_volume_linux.go
@@ -157,7 +157,14 @@ func (r *Runtime) removeVolume(ctx context.Context, v *Volume, force bool) error
 
 	// If the volume is still mounted - force unmount it
 	if err := v.unmount(true); err != nil {
-		return errors.Wrapf(err, "error unmounting volume %s", v.Name())
+		if force {
+			// If force is set, evict the volume, even if errors
+			// occur. Otherwise we'll never be able to get rid of
+			// them.
+			logrus.Errorf("Error unmounting volume %s: %v", v.Name(), err)
+		} else {
+			return errors.Wrapf(err, "error unmounting volume %s", v.Name())
+		}
 	}
 
 	// Set volume as invalid so it can no longer be used