Fix critical race condition and goroutine leak

weed/command/iam.go

@@ -15,6 +15,7 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/security"
 	"github.com/seaweedfs/seaweedfs/weed/util"
+	"github.com/seaweedfs/seaweedfs/weed/util/grace"
 
 	// Import credential stores to register them
 	_ "github.com/seaweedfs/seaweedfs/weed/credential/filer_etc"
@@ -89,8 +90,10 @@ func (iamopt *IamOptions) startIamServer() bool {
 		glog.Fatalf("IAM API Server startup error: %v", iamApiServer_err)
 	}
 	
-	// Ensure cleanup on shutdown
-	defer iamApiServer.Shutdown()
+	// Register shutdown handler to prevent goroutine leak
+	grace.OnInterrupt(func() {
+		iamApiServer.Shutdown()
+	})
 
 	listenAddress := fmt.Sprintf(":%d", *iamopt.port)
 	iamApiListener, iamApiLocalListener, err := util.NewIpAndLocalListeners(*iamopt.ip, *iamopt.port, time.Duration(10)*time.Second)

weed/wdclient/filer_client.go

@@ -470,6 +470,11 @@ func (p *filerVolumeProvider) LookupVolumeIds(ctx context.Context, volumeIds []s
 		for x := int32(0); x < n; x++ {
 			// Get current filer address and health with read lock
 			fc.filerAddressesMu.RLock()
+			if len(fc.filerAddresses) == 0 {
+				fc.filerAddressesMu.RUnlock()
+				lastErr = fmt.Errorf("no filers available")
+				break
+			}
 			if i >= int32(len(fc.filerAddresses)) {
 				// Filer list changed, reset index
 				i = 0