run prepare in parallel

run prepare() -- which consists of creating a network namespace and
mounting the container image is now run in parallel.   This saves 25-40ms.

Signed-off-by: baude <bbaude@redhat.com>

3 files changed, 79 insertions, 51 deletions

diff --git a/libpod/container_internal.go b/libpod/container_internal.go
index cb6b940fd..2af216358 100644
--- a/libpod/container_internal.go
+++ b/libpod/container_internal.go
@@ -750,30 +750,31 @@ func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (err e
 // TODO: Add ability to override mount label so we can use this for Mount() too
 // TODO: Can we use this for export? Copying SHM into the export might not be
 // good
-func (c *Container) mountStorage() (err error) {
+func (c *Container) mountStorage() (string, error) {
+	var err error
 	// Container already mounted, nothing to do
 	if c.state.Mounted {
-		return nil
+		return c.state.Mountpoint, nil
 	}
 
 	if !rootless.IsRootless() {
 		// TODO: generalize this mount code so it will mount every mount in ctr.config.Mounts
 		mounted, err := mount.Mounted(c.config.ShmDir)
 		if err != nil {
-			return errors.Wrapf(err, "unable to determine if %q is mounted", c.config.ShmDir)
+			return "", errors.Wrapf(err, "unable to determine if %q is mounted", c.config.ShmDir)
 		}
 
 		if err := os.Chown(c.config.ShmDir, c.RootUID(), c.RootGID()); err != nil {
-			return errors.Wrapf(err, "failed to chown %s", c.config.ShmDir)
+			return "", errors.Wrapf(err, "failed to chown %s", c.config.ShmDir)
 		}
 
 		if !mounted {
 			shmOptions := fmt.Sprintf("mode=1777,size=%d", c.config.ShmSize)
 			if err := c.mountSHM(shmOptions); err != nil {
-				return err
+				return "", err
 			}
 			if err := os.Chown(c.config.ShmDir, c.RootUID(), c.RootGID()); err != nil {
-				return errors.Wrapf(err, "failed to chown %s", c.config.ShmDir)
+				return "", errors.Wrapf(err, "failed to chown %s", c.config.ShmDir)
 			}
 		}
 	}
@@ -782,28 +783,11 @@ func (c *Container) mountStorage() (err error) {
 	if mountPoint == "" {
 		mountPoint, err = c.mount()
 		if err != nil {
-			return err
+			return "", err
 		}
 	}
-	c.state.Mounted = true
-	c.state.Mountpoint = mountPoint
-	if c.state.UserNSRoot == "" {
-		c.state.RealMountpoint = c.state.Mountpoint
-	} else {
-		c.state.RealMountpoint = filepath.Join(c.state.UserNSRoot, "mountpoint")
-	}
-
-	logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint)
-
-	defer func() {
-		if err != nil {
-			if err2 := c.cleanupStorage(); err2 != nil {
-				logrus.Errorf("Error unmounting storage for container %s: %v", c.ID(), err)
-			}
-		}
-	}()
 
-	return c.save()
+	return mountPoint, nil
 }
 
 // cleanupStorage unmounts and cleans up the container's root filesystem
diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index b25645e5c..94704fc04 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -12,10 +12,12 @@ import (
 	"path"
 	"path/filepath"
 	"strings"
+	"sync"
 	"syscall"
 	"time"
 
 	cnitypes "github.com/containernetworking/cni/pkg/types/current"
+	"github.com/containernetworking/plugins/pkg/ns"
 	crioAnnotations "github.com/containers/libpod/pkg/annotations"
 	"github.com/containers/libpod/pkg/chrootuser"
 	"github.com/containers/libpod/pkg/criu"
@@ -49,24 +51,61 @@ func (c *Container) unmountSHM(mount string) error {
 // prepare mounts the container and sets up other required resources like net
 // namespaces
 func (c *Container) prepare() (err error) {
+	var (
+		wg                              sync.WaitGroup
+		netNS                           ns.NetNS
+		networkStatus                   []*cnitypes.Result
+		createNetNSErr, mountStorageErr error
+		mountPoint                      string
+		saveNetworkStatus               bool
+	)
+
+	wg.Add(2)
+
+	go func() {
+		defer wg.Done()
+		// Set up network namespace if not already set up
+		if c.config.CreateNetNS && c.state.NetNS == nil && !c.config.PostConfigureNetNS {
+			saveNetworkStatus = true
+			netNS, networkStatus, createNetNSErr = c.runtime.createNetNS(c)
+		}
+	}()
 	// Mount storage if not mounted
-	if err := c.mountStorage(); err != nil {
-		return err
-	}
+	go func() {
+		defer wg.Done()
+		mountPoint, mountStorageErr = c.mountStorage()
+	}()
 
-	// Set up network namespace if not already set up
-	if c.config.CreateNetNS && c.state.NetNS == nil && !c.config.PostConfigureNetNS {
-		if err := c.runtime.createNetNS(c); err != nil {
-			// Tear down storage before exiting to make sure we
-			// don't leak mounts
-			if err2 := c.cleanupStorage(); err2 != nil {
-				logrus.Errorf("Error cleaning up storage for container %s: %v", c.ID(), err2)
-			}
-			return err
+	wg.Wait()
+	if createNetNSErr != nil {
+		if mountStorageErr != nil {
+			logrus.Error(createNetNSErr)
+			return mountStorageErr
 		}
+		return createNetNSErr
+	}
+	if mountStorageErr != nil {
+		return mountStorageErr
 	}
 
-	return nil
+	// Assign NetNS attributes to container
+	if saveNetworkStatus {
+		c.state.NetNS = netNS
+		c.state.NetworkStatus = networkStatus
+	}
+
+	// Finish up mountStorage
+	c.state.Mounted = true
+	c.state.Mountpoint = mountPoint
+	if c.state.UserNSRoot == "" {
+		c.state.RealMountpoint = c.state.Mountpoint
+	} else {
+		c.state.RealMountpoint = filepath.Join(c.state.UserNSRoot, "mountpoint")
+	}
+
+	logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint)
+	// Save the container
+	return c.save()
 }
 
 // cleanupNetwork unmounts and cleans up the container's network
@@ -104,7 +143,6 @@ func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) {
 			g.AddOrReplaceLinuxNamespace(spec.NetworkNamespace, c.state.NetNS.Path())
 		}
 	}
-
 	// Check if the spec file mounts contain the label Relabel flags z or Z.
 	// If they do, relabel the source directory and then remove the option.
 	for _, m := range g.Mounts() {
diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go
index acb4e2a90..0d9ec2809 100644
--- a/libpod/networking_linux.go
+++ b/libpod/networking_linux.go
@@ -48,12 +48,12 @@ func (r *Runtime) getPodNetwork(id, name, nsPath string, networks []string, port
 }
 
 // Create and configure a new network namespace for a container
-func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) (err error) {
+func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) ([]*cnitypes.Result, error) {
 	podNetwork := r.getPodNetwork(ctr.ID(), ctr.Name(), ctrNS.Path(), ctr.config.Networks, ctr.config.PortMappings, ctr.config.StaticIP)
 
 	results, err := r.netPlugin.SetUpPod(podNetwork)
 	if err != nil {
-		return errors.Wrapf(err, "error configuring network namespace for container %s", ctr.ID())
+		return nil, errors.Wrapf(err, "error configuring network namespace for container %s", ctr.ID())
 	}
 	defer func() {
 		if err != nil {
@@ -63,15 +63,14 @@ func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) (err error) {
 		}
 	}()
 
-	ctr.state.NetNS = ctrNS
-	ctr.state.NetworkStatus = make([]*cnitypes.Result, 0)
+	networkStatus := make([]*cnitypes.Result, 1)
 	for idx, r := range results {
 		logrus.Debugf("[%d] CNI result: %v", idx, r.String())
 		resultCurrent, err := cnitypes.GetResult(r)
 		if err != nil {
-			return errors.Wrapf(err, "error parsing CNI plugin result %q: %v", r.String(), err)
+			return nil, errors.Wrapf(err, "error parsing CNI plugin result %q: %v", r.String(), err)
 		}
-		ctr.state.NetworkStatus = append(ctr.state.NetworkStatus, resultCurrent)
+		networkStatus = append(ctr.state.NetworkStatus, resultCurrent)
 	}
 
 	// Add firewall rules to ensure the container has network access.
@@ -82,18 +81,18 @@ func (r *Runtime) configureNetNS(ctr *Container, ctrNS ns.NetNS) (err error) {
 			PrevResult: netStatus,
 		}
 		if err := r.firewallBackend.Add(firewallConf); err != nil {
-			return errors.Wrapf(err, "error adding firewall rules for container %s", ctr.ID())
+			return nil, errors.Wrapf(err, "error adding firewall rules for container %s", ctr.ID())
 		}
 	}
 
-	return nil
+	return networkStatus, nil
 }
 
 // Create and configure a new network namespace for a container
-func (r *Runtime) createNetNS(ctr *Container) (err error) {
+func (r *Runtime) createNetNS(ctr *Container) (ns.NetNS, []*cnitypes.Result, error) {
 	ctrNS, err := netns.NewNS()
 	if err != nil {
-		return errors.Wrapf(err, "error creating network namespace for container %s", ctr.ID())
+		return nil, nil, errors.Wrapf(err, "error creating network namespace for container %s", ctr.ID())
 	}
 	defer func() {
 		if err != nil {
@@ -104,7 +103,9 @@ func (r *Runtime) createNetNS(ctr *Container) (err error) {
 	}()
 
 	logrus.Debugf("Made network namespace at %s for container %s", ctrNS.Path(), ctr.ID())
-	return r.configureNetNS(ctr, ctrNS)
+
+	networkStatus, err := r.configureNetNS(ctr, ctrNS)
+	return ctrNS, networkStatus, err
 }
 
 // Configure the network namespace for a rootless container
@@ -173,7 +174,12 @@ func (r *Runtime) setupNetNS(ctr *Container) (err error) {
 	if err != nil {
 		return err
 	}
-	return r.configureNetNS(ctr, netNS)
+	networkStatus, err := r.configureNetNS(ctr, netNS)
+
+	// Assign NetNS attributes to container
+	ctr.state.NetNS = netNS
+	ctr.state.NetworkStatus = networkStatus
+	return err
 }
 
 // Join an existing network namespace