Improve-worker (#7367)

* ♻️ refactor(worker): remove goto

* ♻️ refactor(worker): let manager loop exit by itself

* ♻️ refactor(worker): fix race condition when closing worker

CloseSend is not safe to call when another
goroutine concurrently calls Send. streamCancel
already handles proper stream closure. Also,
streamExit signal should be called AFTER
sending shutdownMsg

Now the worker has no race condition if stopped
during any moment (hopefully, tested with -race
flag)

* 🐛 fix(task_logger): deadlock in log closure

* 🐛 fix(balance): fix balance task

Removes the outdated "UnloadVolume" step as it is handled by "DeleteVolume".

#7346

weed/worker/worker.go

@@ -7,7 +7,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"sync"
 	"time"
 
 	"github.com/seaweedfs/seaweedfs/weed/glog"
@@ -29,7 +28,6 @@ type Worker struct {
 	cmds           chan workerCommand
 	state          *workerState
 	taskLogHandler *tasks.TaskLogHandler
-	closeOnce      sync.Once
 }
 type workerState struct {
 	running         bool
@@ -201,13 +199,14 @@ func (w *Worker) managerLoop() {
 		stopChan:     make(chan struct{}),
 		currentTasks: make(map[string]*types.TaskInput),
 	}
-
+out:
 	for cmd := range w.cmds {
 		switch cmd.action {
 		case ActionStart:
 			w.handleStart(cmd)
 		case ActionStop:
 			w.handleStop(cmd)
+			break out
 		case ActionGetStatus:
 			respCh := cmd.data.(statusResponse)
 			var currentTasks []types.TaskInput
@@ -495,15 +494,15 @@ func (w *Worker) Stop() error {
 	// Wait for tasks to finish
 	timeout := time.NewTimer(30 * time.Second)
 	defer timeout.Stop()
+out:
 	for w.getTaskLoad() > 0 {
 		select {
 		case <-timeout.C:
 			glog.Warningf("Worker %s stopping with %d tasks still running", w.id, w.getTaskLoad())
-			goto end_wait
+			break out
 		case <-time.After(100 * time.Millisecond):
 		}
 	}
-end_wait:
 
 	// Disconnect from admin server
 	if adminClient := w.getAdmin(); adminClient != nil {
@@ -511,10 +510,6 @@ end_wait:
 			glog.Errorf("Error disconnecting from admin server: %v", err)
 		}
 	}
-
-	w.closeOnce.Do(func() {
-		close(w.cmds)
-	})
 	glog.Infof("Worker %s stopped", w.id)
 	return nil
 }
@@ -731,7 +726,6 @@ func (w *Worker) executeTask(task *types.TaskInput) {
 			fileLogger.Info("Task %s completed successfully", task.ID)
 		}
 	}
-	return
 }
 
 // completeTask reports task completion to admin server