}
  }

  /** A reference to a value. */
  interface ValueReference<K, V> {
    /** Returns the value. Does not block or throw exceptions. */
    @CheckForNull
    V get();

    /**
     * Waits for a value that may still be loading. Unlike get(), this method can block (in the case
     * of FutureValueReference).
     *
     * @throws ExecutionException if the loading thread throws an exception

		err = errLockNotInitialized
	default:
		err = errors.New(r.Err)
	}
	return ok, err
}

// RLock calls read lock REST API.
func (c *lockRESTClient) RLock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
	return c.call(ctx, lockRPCRLock, &args)
}

// Lock calls lock REST API.
func (c *lockRESTClient) Lock(ctx context.Context, args dsync.LockArgs) (reply bool, err error) {
	return c.call(ctx, lockRPCLock, &args)
}

		if _, err = xlStorage.ReadFile(context.Background(), volume, "myobject", -1, buf, v); err == nil {
			t.Fatalf("expected: error, got: <nil>")
		}
	}

	for l := 0; l < 2; l++ {
		// Following block validates all ReadFile test cases.
		for i, testCase := range testCases {
			var n int64
			// Common read buffer.
			buf := make([]byte, testCase.bufSize)

- For raw block CSI volumes on Kubernetes, kubelet was incorrectly calling CSI `NodeStageVolume` for every single "map" (i.e. raw block "mount") operation for a volume already attached to the node. This change modified that behavior to ensure it is only called once per volume per node. ([#112403](https://github.com/kubern...

}

// RLockHandler - Acquires an RLock.
func (l *lockRESTServer) RLockHandler(args *dsync.LockArgs) (*dsync.LockResp, *grid.RemoteErr) {
	resp := lockRPCRLock.NewResponse()
	success, err := l.ll.RLock(context.Background(), *args)
	if err == nil && !success {
		err = errLockConflict
	}
	return l.makeResp(resp, err)
}

// RUnlockHandler - releases the acquired read lock.

- Fixed a regression preventing garbage collection of RBAC role and binding objects ([#90534](https://github.com/kubernetes/kubernetes/pull/90534), [@apelisse](https://github.com/apelisse)) [SIG Auth]
- Fixed cleanup of raw block devices after kubelet restart. ([#83451](https://github.com/kubernetes/kubernetes/pull/83451), [@jsafrane](https://github.com/jsafrane)) [SIG Node, Storage and Testing]

			Source:    t.Name(),
			Owner:     "owner",
			Quorum:    &quorum,
		}
		ok, err := l.RLock(ctx, arg)
		if err != nil {
			t.Fatal(err)
		}
		if !ok {
			t.Fatal("did not get read lock")
		}
		// RLock twice
		ok, err = l.RLock(ctx, arg)
		if err != nil {
			t.Fatal(err)
		}
		if !ok {
			t.Fatal("did not get write lock")
		}

		rResources[i] = arg.Resources[0]
	}

package cmd

import (
	"context"
	"os"
	"reflect"
	"sync"
	"testing"

	"github.com/minio/minio/internal/dsync"
)

// Helper function to create a lock server for testing
func createLockTestServer(ctx context.Context, t *testing.T) (string, *lockRESTServer, string) {
	obj, fsDir, err := prepareFS(ctx)
	if err != nil {
		t.Fatal(err)
	}

* Image GC logic should compensate for reserved blocks ([#27996](https://github.com/kubernetes/kubernetes/pull/27996), [@ronnielai](https://github.com/ronnielai))
* Bump minimum API version for docker to 1.21 ([#27208](https://github.com/kubernetes/kubernetes/pull/27208), [@yujuhong](https://github.com/yujuhong))

		time.Sleep(time.Duration(d))
	}

	l.mutex.Lock()
	defer l.mutex.Unlock()
	var locksHeld int64
	if locksHeld, reply = l.lockMap[args.Resources[0]]; !reply { // No lock is held on the given name
		return false, fmt.Errorf("RUnlock attempted on an unlocked entity: %s", args.Resources[0])
	}
	if reply = locksHeld != WriteLock; !reply { // A write-lock is held, cannot release a read lock