use only one metadata follow process

weed/mount/filer_conf.go

@@ -3,19 +3,15 @@ package mount
 import (
 	"errors"
 	"fmt"
-	"path/filepath"
-	"sync/atomic"
-	"time"
-
 	"github.com/seaweedfs/seaweedfs/weed/filer"
 	"github.com/seaweedfs/seaweedfs/weed/glog"
-	"github.com/seaweedfs/seaweedfs/weed/pb"
+	"github.com/seaweedfs/seaweedfs/weed/mount/meta_cache"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/util"
+	"path/filepath"
 )
 
-func (wfs *WFS) subscribeFilerConfEvents() (func(), error) {
-	now := time.Now()
+func (wfs *WFS) subscribeFilerConfEvents() (*meta_cache.MetadataFollower, error) {
 	confDir := filer.DirectoryEtcSeaweedFS
 	confName := filer.FilerConfName
 	confFullName := filepath.Join(filer.DirectoryEtcSeaweedFS, filer.FilerConfName)
@@ -71,41 +67,9 @@ func (wfs *WFS) subscribeFilerConfEvents() (func(), error) {
 
 		return nil
 	}
-
-	metadataFollowOption := &pb.MetadataFollowOption{
-		ClientName:             "fuse",
-		ClientId:               wfs.signature,
-		ClientEpoch:            1,
-		SelfSignature:          0,
-		PathPrefix:             confFullName,
-		AdditionalPathPrefixes: nil,
-		StartTsNs:              now.UnixNano(),
-		StopTsNs:               0,
-		EventErrorType:         pb.FatalOnError,
-	}
-
-	return func() {
-		// sync new conf changes
-		util.RetryUntil("followFilerConfChanges", func() error {
-			metadataFollowOption.ClientEpoch++
-			i := atomic.LoadInt32(&wfs.option.filerIndex)
-			n := len(wfs.option.FilerAddresses)
-			err = pb.FollowMetadata(wfs.option.FilerAddresses[i], wfs.option.GrpcDialOption, metadataFollowOption, processEventFn)
-			if err == nil {
-				atomic.StoreInt32(&wfs.option.filerIndex, i)
-				return nil
-			}
-
-			i++
-			if i >= int32(n) {
-				i = 0
-			}
-
-			return err
-		}, func(err error) bool {
-			glog.V(0).Infof("fuse follow filer conf changes: %v", err)
-			return true
-		})
+	return &meta_cache.MetadataFollower{
+		PathPrefixToWatch: confFullName,
+		ProcessEventFn:    processEventFn,
 	}, nil
 }