Convert pods to SHM locks

Signed-off-by: Matthew Heon <matthew.heon@gmail.com>

libpod/boltdb_state_internal.go

@@ -323,10 +323,9 @@ func (s *BoltState) getPodFromDB(id []byte, pod *Pod, podBkt *bolt.Bucket) error
 	}
 
 	// Get the lock
-	lockPath := filepath.Join(s.runtime.lockDir, string(id))
-	lock, err := storage.GetLockfile(lockPath)
+	lock, err := s.runtime.lockManager.RetrieveLock(pod.config.LockID)
 	if err != nil {
-		return errors.Wrapf(err, "error retrieving lockfile for pod %s", string(id))
+		return errors.Wrapf(err, "error retrieving lock for pod %s", string(id))
 	}
 	pod.lock = lock
 

libpod/container_internal.go

@@ -451,12 +451,11 @@ func (c *Container) refresh() error {
 	}
 
 	// We need to pick up a new lock
-	lock, err := c.runtime.lockManager.AllocateLock()
+	lock, err := c.runtime.lockManager.RetrieveLock(c.config.LockID)
 	if err != nil {
 		return errors.Wrapf(err, "error acquiring lock for container %s", c.ID())
 	}
 	c.lock = lock
-	c.config.LockID = c.lock.ID()
 
 	if err := c.save(); err != nil {
 		return errors.Wrapf(err, "error refreshing state for container %s", c.ID())

libpod/lock/shm/shm_lock_test.go

@@ -18,7 +18,7 @@ import (
 // We can at least verify that the locks work within the local process.
 
 // 4 * BITMAP_SIZE to ensure we have to traverse bitmaps
-const numLocks uint32 = 4 * BitmapSize
+var numLocks uint32 = 4 * BitmapSize
 
 const lockPath = "/libpod_test"
 
@@ -155,7 +155,8 @@ func TestAllocateTwoLocksGetsDifferentLocks(t *testing.T) {
 func TestAllocateAllLocksSucceeds(t *testing.T) {
 	runLockTest(t, func(t *testing.T, locks *SHMLocks) {
 		sems := make(map[uint32]bool)
-		for i := 0; i < numLocks; i++ {
+		var i uint32
+		for i = 0; i < numLocks; i++ {
 			sem, err := locks.AllocateSemaphore()
 			assert.NoError(t, err)
 
@@ -172,7 +173,8 @@ func TestAllocateAllLocksSucceeds(t *testing.T) {
 func TestAllocateTooManyLocksFails(t *testing.T) {
 	runLockTest(t, func(t *testing.T, locks *SHMLocks) {
 		// Allocate all locks
-		for i := 0; i < numLocks; i++ {
+		var i uint32
+		for i = 0; i < numLocks; i++ {
 			_, err := locks.AllocateSemaphore()
 			assert.NoError(t, err)
 		}
@@ -187,7 +189,8 @@ func TestAllocateTooManyLocksFails(t *testing.T) {
 func TestAllocateDeallocateCycle(t *testing.T) {
 	runLockTest(t, func(t *testing.T, locks *SHMLocks) {
 		// Allocate all locks
-		for i := 0; i < numLocks; i++ {
+		var i uint32
+		for i = 0; i < numLocks; i++ {
 			_, err := locks.AllocateSemaphore()
 			assert.NoError(t, err)
 		}

libpod/pod.go

@@ -3,7 +3,7 @@ package libpod
 import (
 	"time"
 
-	"github.com/containers/storage"
+	"github.com/containers/libpod/libpod/lock"
 	"github.com/cri-o/ocicni/pkg/ocicni"
 	"github.com/pkg/errors"
 )
@@ -26,7 +26,7 @@ type Pod struct {
 
 	valid   bool
 	runtime *Runtime
-	lock    storage.Locker
+	lock    lock.Locker
 }
 
 // PodConfig represents a pod's static configuration
@@ -60,6 +60,9 @@ type PodConfig struct {
 
 	// Time pod was created
 	CreatedTime time.Time `json:"created"`
+
+	// ID of the pod's lock
+	LockID uint32 `json:"lockID"`
 }
 
 // podState represents a pod's state

libpod/pod_easyjson.go

@@ -501,6 +501,8 @@ func easyjsonBe091417DecodeGithubComContainersLibpodLibpod4(in *jlexer.Lexer, ou
 			if data := in.Raw(); in.Ok() {
 				in.AddError((out.CreatedTime).UnmarshalJSON(data))
 			}
+		case "lockID":
+			out.LockID = uint32(in.Uint32())
 		default:
 			in.SkipRecursive()
 		}
@@ -675,6 +677,16 @@ func easyjsonBe091417EncodeGithubComContainersLibpodLibpod4(out *jwriter.Writer,
 		}
 		out.Raw((in.CreatedTime).MarshalJSON())
 	}
+	{
+		const prefix string = ",\"lockID\":"
+		if first {
+			first = false
+			out.RawString(prefix[1:])
+		} else {
+			out.RawString(prefix)
+		}
+		out.Uint32(uint32(in.LockID))
+	}
 	out.RawByte('}')
 }
 

libpod/pod_internal.go

@@ -7,7 +7,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/stringid"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -24,15 +23,6 @@ func newPod(lockDir string, runtime *Runtime) (*Pod, error) {
 	pod.state = new(podState)
 	pod.runtime = runtime
 
-	// Path our lock file will reside at
-	lockPath := filepath.Join(lockDir, pod.config.ID)
-	// Grab a lockfile at the given path
-	lock, err := storage.GetLockfile(lockPath)
-	if err != nil {
-		return nil, errors.Wrapf(err, "error creating lockfile for new pod")
-	}
-	pod.lock = lock
-
 	return pod, nil
 }
 
@@ -55,6 +45,8 @@ func (p *Pod) save() error {
 }
 
 // Refresh a pod's state after restart
+// This cannot lock any other pod, but may lock individual containers, as those
+// will have refreshed by the time pod refresh runs.
 func (p *Pod) refresh() error {
 	// Need to to an update from the DB to pull potentially-missing state
 	if err := p.runtime.state.UpdatePod(p); err != nil {
@@ -65,6 +57,13 @@ func (p *Pod) refresh() error {
 		return ErrPodRemoved
 	}
 
+	// Retrieve the pod's lock
+	lock, err := p.runtime.lockManager.RetrieveLock(p.config.LockID)
+	if err != nil {
+		return errors.Wrapf(err, "error retrieving lock for pod %s", p.ID())
+	}
+	p.lock = lock
+
 	// We need to recreate the pod's cgroup
 	if p.config.UsePodCgroup {
 		switch p.runtime.config.CgroupManager {

libpod/runtime_ctr.go

@@ -81,7 +81,11 @@ func (r *Runtime) newContainer(ctx context.Context, rSpec *spec.Spec, options ..
 		return nil, errors.Wrapf(err, "error allocating lock for new container")
 	}
 	ctr.lock = lock
-	ctr.config.LockID = c.lock.ID()
+	ctr.config.LockID = ctr.lock.ID()
+
+	ctr.valid = true
+	ctr.state.State = ContainerStateConfigured
+	ctr.runtime = r
 
 	ctr.valid = true
 	ctr.state.State = ContainerStateConfigured

libpod/runtime_pod_linux.go

@@ -48,6 +48,14 @@ func (r *Runtime) NewPod(ctx context.Context, options ...PodCreateOption) (*Pod,
 		pod.config.Name = name
 	}
 
+	// Allocate a lock for the pod
+	lock, err := r.lockManager.AllocateLock()
+	if err != nil {
+		return nil, errors.Wrapf(err, "error allocating lock for new pod")
+	}
+	pod.lock = lock
+	pod.config.LockID = pod.lock.ID()
+
 	pod.valid = true
 
 	// Check CGroup parent sanity, and set it if it was not set