From 19c51f3f3cca08ee27e0acd45a1ceeb841af0802 Mon Sep 17 00:00:00 2001
From: Frank <fwessels@xs4all.nl>
Date: Wed, 19 Oct 2016 18:27:36 +0200
Subject: [PATCH] Added ForceUnlock to namespace-lock (#2990)

---
 cmd/namespace-lock.go      | 23 +++++++++++++++++++++++
 cmd/namespace-lock_test.go | 36 +++++++++++++++++++++++++++++++++---
 2 files changed, 56 insertions(+), 3 deletions(-)

diff --git a/cmd/namespace-lock.go b/cmd/namespace-lock.go
index 4b379f3af..a510f4320 100644
--- a/cmd/namespace-lock.go
+++ b/cmd/namespace-lock.go
@@ -245,3 +245,26 @@ func (n *nsLockMap) RUnlock(volume, path, opsID string) {
 	readLock := true
 	n.unlock(volume, path, opsID, readLock)
 }
+
+// ForceUnlock - forcefully unlock a lock based on name.
+func (n *nsLockMap) ForceUnlock(volume, path string) {
+	n.lockMapMutex.Lock()
+	defer n.lockMapMutex.Unlock()
+
+	if n.isDist { // For distributed mode, broadcast ForceUnlock message.
+		dsync.NewDRWMutex(pathutil.Join(volume, path)).ForceUnlock()
+	}
+
+	param := nsParam{volume, path}
+	if _, found := n.lockMap[param]; found {
+		// Remove lock from the map.
+		delete(n.lockMap, param)
+
+		// delete the lock state entry for given
+		// <volume, path> pair.
+		err := n.deleteLockInfoEntryForVolumePath(param)
+		if err != nil {
+			errorIf(err, "Failed to delete lock info entry.")
+		}
+	}
+}
diff --git a/cmd/namespace-lock_test.go b/cmd/namespace-lock_test.go
index ac53133a5..e41d91512 100644
--- a/cmd/namespace-lock_test.go
+++ b/cmd/namespace-lock_test.go
@@ -68,7 +68,7 @@ func TestNamespaceLockTest(t *testing.T) {
 	if !ok && testCase.shouldPass {
 		t.Errorf("Lock in map missing.")
 	}
-	// Validate loced ref count.
+	// Validate locked ref count.
 	if testCase.lockedRefCount != nsLk.ref && testCase.shouldPass {
 		t.Errorf("Test %d fails, expected to pass. Wanted ref count is %d, got %d", 1, testCase.lockedRefCount, nsLk.ref)
 	}
@@ -91,7 +91,7 @@ func TestNamespaceLockTest(t *testing.T) {
 	if !ok && testCase.shouldPass {
 		t.Errorf("Lock in map missing.")
 	}
-	// Validate loced ref count.
+	// Validate locked ref count.
 	if testCase.lockedRefCount != nsLk.ref && testCase.shouldPass {
 		t.Errorf("Test %d fails, expected to pass. Wanted ref count is %d, got %d", 1, testCase.lockedRefCount, nsLk.ref)
 	}
@@ -114,7 +114,7 @@ func TestNamespaceLockTest(t *testing.T) {
 	if !ok && testCase.shouldPass {
 		t.Errorf("Lock in map missing.")
 	}
-	// Validate loced ref count.
+	// Validate locked ref count.
 	if testCase.lockedRefCount != nsLk.ref && testCase.shouldPass {
 		t.Errorf("Test %d fails, expected to pass. Wanted ref count is %d, got %d", 3, testCase.lockedRefCount, nsLk.ref)
 	}
@@ -380,5 +380,35 @@ func TestLockStats(t *testing.T) {
 	expectedLockStats = expectedResult[7]
 	// verify the actual lock info with the expected one.
 	verifyGlobalLockStats(expectedLockStats, t, 8)
+}
+
+// Tests functionality to forcefully unlock locks.
+func TestNamespaceForceUnlockTest(t *testing.T) {
+
+	// Create lock.
+	nsMutex.Lock("bucket", "object", "11-11")
+	// Forcefully unlock lock.
+	nsMutex.ForceUnlock("bucket", "object")
+
+	ch := make(chan struct{}, 1)
+
+	go func() {
+		// Try to claim lock again.
+		nsMutex.Lock("bucket", "object", "22-22")
+		// And signal succes.
+		ch <- struct{}{}
+	}()
+
+	select {
+		case <-ch:
+			// Signalled so all is fine.
+			break
+
+		case <-time.After(100*time.Millisecond):
+			// In case we hit the time out, the lock has not been cleared.
+			t.Errorf("Lock not cleared.")
+	}
 
+	// Clean up lock.
+	nsMutex.ForceUnlock("bucket", "object")
 }