Merge pull request #4624 from mheon/refresh_volume_locks

Ensure volumes reacquire locks on state refresh

2 files changed, 26 insertions, 4 deletions

diff --git a/libpod/runtime.go b/libpod/runtime.go
index 42e6782e9..3873079ce 100644
--- a/libpod/runtime.go
+++ b/libpod/runtime.go
@@ -625,7 +625,8 @@ func (r *Runtime) refresh(alivePath string) error {
 	}
 
 	// Next refresh the state of all containers to recreate dirs and
-	// namespaces, and all the pods to recreate cgroups
+	// namespaces, and all the pods to recreate cgroups.
+	// Containers, pods, and volumes must also reacquire their locks.
 	ctrs, err := r.state.AllContainers()
 	if err != nil {
 		return errors.Wrapf(err, "error retrieving all containers from state")
@@ -634,10 +635,14 @@ func (r *Runtime) refresh(alivePath string) error {
 	if err != nil {
 		return errors.Wrapf(err, "error retrieving all pods from state")
 	}
-	// No locks are taken during pod and container refresh.
-	// Furthermore, the pod and container refresh() functions are not
+	vols, err := r.state.AllVolumes()
+	if err != nil {
+		return errors.Wrapf(err, "error retrieving all volumes from state")
+	}
+	// No locks are taken during pod, volume, and container refresh.
+	// Furthermore, the pod/volume/container refresh() functions are not
 	// allowed to take locks themselves.
-	// We cannot assume that any pod or container has a valid lock until
+	// We cannot assume that any pod/volume/container has a valid lock until
 	// after this function has returned.
 	// The runtime alive lock should suffice to provide mutual exclusion
 	// until this has run.
@@ -651,6 +656,11 @@ func (r *Runtime) refresh(alivePath string) error {
 			logrus.Errorf("Error refreshing pod %s: %v", pod.ID(), err)
 		}
 	}
+	for _, vol := range vols {
+		if err := vol.refresh(); err != nil {
+			logrus.Errorf("Error refreshing volume %s: %v", vol.Name(), err)
+		}
+	}
 
 	// Create a file indicating the runtime is alive and ready
 	file, err := os.OpenFile(alivePath, os.O_RDONLY|os.O_CREATE, 0644)
diff --git a/libpod/volume_internal.go b/libpod/volume_internal.go
index 42b935e7c..e89b3484d 100644
--- a/libpod/volume_internal.go
+++ b/libpod/volume_internal.go
@@ -5,6 +5,7 @@ import (
 	"path/filepath"
 
 	"github.com/containers/libpod/libpod/define"
+	"github.com/pkg/errors"
 )
 
 // Creates a new volume
@@ -46,3 +47,14 @@ func (v *Volume) update() error {
 func (v *Volume) save() error {
 	return v.runtime.state.SaveVolume(v)
 }
+
+// Refresh volume state after a restart.
+func (v *Volume) refresh() error {
+	lock, err := v.runtime.lockManager.AllocateAndRetrieveLock(v.config.LockID)
+	if err != nil {
+		return errors.Wrapf(err, "error acquiring lock %d for volume %s", v.config.LockID, v.Name())
+	}
+	v.lock = lock
+
+	return nil
+}