[#364] node: Stop flushing big object when termination signal received

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

pkg/local_object_storage/writecache/flush.go

@@ -35,6 +35,17 @@ const (
 
 // runFlushLoop starts background workers which periodically flush objects to the blobstor.
 func (c *cache) runFlushLoop() {
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	ch := c.closeCh
+	c.wg.Add(1)
+	go func() {
+		<-ch
+		cancel()
+		c.wg.Done()
+	}()
+
 	for i := 0; i < c.workersCount; i++ {
 		c.wg.Add(1)
 		go c.workerFlushSmall()
@@ -42,7 +53,7 @@ func (c *cache) runFlushLoop() {
 
 	c.wg.Add(1)
 	go func() {
-		c.workerFlushBig(context.TODO())
+		c.workerFlushBig(ctx)
 		c.wg.Done()
 	}()
 
@@ -211,7 +222,7 @@ func (c *cache) flushFSTree(ctx context.Context, ignoreErrors bool) error {
 		return nil
 	}
 
-	_, err := c.fsTree.Iterate(prm)
+	_, err := c.fsTree.Iterate(ctx, prm)
 	return err
 }