add distributed lock manager

weed/server/filer_server.go

@@ -3,6 +3,7 @@ package weed_server
 import (
 	"context"
 	"fmt"
+	"github.com/seaweedfs/seaweedfs/weed/cluster/lock_manager"
 	"net/http"
 	"os"
 	"sync"
@@ -94,6 +95,9 @@ type FilerServer struct {
 	// track known metadata listeners
 	knownListenersLock sync.Mutex
 	knownListeners     map[int32]int32
+
+	// distributed lock manager
+	dlm *lock_manager.LockManager
 }
 
 func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption) (fs *FilerServer, err error) {
@@ -181,6 +185,9 @@ func NewFilerServer(defaultMux, readonlyMux *http.ServeMux, option *FilerOption)
 		fs.filer.Shutdown()
 	})
 
+	fs.dlm = lock_manager.NewLockManager()
+	fs.filer.LockRing.SetTakeSnapshotCallback(fs.OnDlmChangeSnapshot)
+
 	return fs, nil
 }