Parallelize read-only volume check pass for volume.check.disk. (#7602)

weed/shell/common.go

@@ -2,6 +2,7 @@ package shell
 
 import (
 	"errors"
+	"fmt"
 	"sync"
 )
 
@@ -64,6 +65,13 @@ func (ewg *ErrorWaitGroup) Add(f ErrorWaitGroupTask) {
 	}()
 }
 
+// AddErrorf adds an error to an ErrorWaitGroupTask result, without queueing any goroutines.
+func (ewg *ErrorWaitGroup) AddErrorf(format string, a ...interface{}) {
+	ewg.errorsMu.Lock()
+	ewg.errors = append(ewg.errors, fmt.Errorf(format, a...))
+	ewg.errorsMu.Unlock()
+}
+
 // Wait sleeps until all ErrorWaitGroupTasks are completed, then returns errors for them.
 func (ewg *ErrorWaitGroup) Wait() error {
 	ewg.wg.Wait()