Rewrite copy-up to use buildah Copier

The old copy-up implementation was very unhappy with symlinks,
which could cause containers to fail to start for unclear reasons
when a directory we wanted to copy-up contained one. Rewrite to
use the Buildah Copier, which is more recent and should be both
safer and less likely to blow up over links.

At the same time, fix a deadlock in copy-up for volumes requiring
mounting - the Mountpoint() function tried to take the
already-acquired volume lock.

Fixes #6003

Signed-off-by: Matthew Heon <mheon@redhat.com>

1 files changed, 9 insertions, 2 deletions

diff --git a/libpod/volume.go b/libpod/volume.go
index 4c137cb8e..5cc5e7e40 100644
--- a/libpod/volume.go
+++ b/libpod/volume.go
@@ -130,11 +130,18 @@ func (v *Volume) MountPoint() (string, error) {
 		if err := v.update(); err != nil {
 			return "", err
 		}
+	}
+
+	return v.mountPoint(), nil
+}
 
-		return v.state.MountPoint, nil
+// Internal-only helper for volume mountpoint
+func (v *Volume) mountPoint() string {
+	if v.UsesVolumeDriver() {
+		return v.state.MountPoint
 	}
 
-	return v.config.MountPoint, nil
+	return v.config.MountPoint
 }
 
 // Options return the volume's options