feat: Prevent multiple instances of "ipfs routing reprovide" running together.

CHANGELOG.md

@@ -18,6 +18,8 @@ The following emojis are used to highlight certain changes:
 
 ### Changed
 
+- `provider`: Prevent multiple instances of reprovider.Reprovide() from running at the same time. [#834](https://github.com/ipfs/boxo/pull/834)
+
 ### Removed
 
 ### Fixed

provider/reprovider.go

@@ -42,6 +42,7 @@
 	ctx     context.Context
 	close   context.CancelFunc
 	closewg sync.WaitGroup
+	mu      sync.Mutex
 
 	reprovideInterval        time.Duration
 	initalReprovideDelay     time.Duration
@@ -470,6 +471,12 @@
 		return nil
 	}
 
+	ok := s.mu.TryLock()
+	if !ok {
+		return fmt.Errorf("instance of reprovide already running")
+	}
+	defer s.mu.Unlock()
+
 	kch, err := s.keyProvider(ctx)
 	if err != nil {
 		return err