Fix update of `SeaweedFS_volumeServer_volumes` gauge metrics when EC shards are unmounted (#6776)

weed/storage/erasure_coding/ec_shard.go

@@ -45,11 +45,19 @@ func NewEcVolumeShard(diskType types.DiskType, dirname string, collection string
 	}
 	v.ecdFileSize = ecdFi.Size()
 
-	stats.VolumeServerVolumeGauge.WithLabelValues(v.Collection, "ec_shards").Inc()
+	v.Mount()
 
 	return
 }
 
+func (shard *EcVolumeShard) Mount() {
+	stats.VolumeServerVolumeGauge.WithLabelValues(shard.Collection, "ec_shards").Inc()
+}
+
+func (shard *EcVolumeShard) Unmount() {
+	stats.VolumeServerVolumeGauge.WithLabelValues(shard.Collection, "ec_shards").Dec()
+}
+
 func (shard *EcVolumeShard) Size() int64 {
 	return shard.ecdFileSize
 }
@@ -88,8 +96,8 @@ func (shard *EcVolumeShard) Close() {
 }
 
 func (shard *EcVolumeShard) Destroy() {
+	shard.Unmount()
 	os.Remove(shard.FileName() + ToExt(int(shard.ShardId)))
-	stats.VolumeServerVolumeGauge.WithLabelValues(shard.Collection, "ec_shards").Dec()
 }
 
 func (shard *EcVolumeShard) ReadAt(buf []byte, offset int64) (int, error) {

weed/storage/erasure_coding/ec_volume.go

@@ -111,7 +111,7 @@ func (ev *EcVolume) DeleteEcVolumeShard(shardId ShardId) (ecVolumeShard *EcVolum
 	}
 
 	ecVolumeShard = ev.Shards[foundPosition]
-
+	ecVolumeShard.Unmount()
 	ev.Shards = append(ev.Shards[:foundPosition], ev.Shards[foundPosition+1:]...)
 	return ecVolumeShard, true
 }