diff --git a/lib/private/lock/abstractlockingprovider.php b/lib/private/lock/abstractlockingprovider.php
new file mode 100644
index 0000000000..290bb77e52
--- /dev/null
+++ b/lib/private/lock/abstractlockingprovider.php
@@ -0,0 +1,96 @@
+<?php
+/**
+ * @author Morris Jobke <hey@morrisjobke.de>
+ * @author Robin Appelman <icewind@owncloud.com>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @copyright Copyright (c) 2015, ownCloud, Inc.
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+namespace OC\Lock;
+
+use OCP\Lock\ILockingProvider;
+
+abstract class AbstractLockingProvider implements ILockingProvider {
+	protected $acquiredLocks = [
+		'shared' => [],
+		'exclusive' => []
+	];
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markAcquire($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			if (!isset($this->acquiredLocks['shared'][$path])) {
+				$this->acquiredLocks['shared'][$path] = 0;
+			}
+			$this->acquiredLocks['shared'][$path]++;
+		} else {
+			$this->acquiredLocks['exclusive'][$path] = true;
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @param int $type self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markRelease($path, $type) {
+		if ($type === self::LOCK_SHARED) {
+			if (isset($this->acquiredLocks['shared'][$path]) and $this->acquiredLocks['shared'][$path] > 0) {
+				$this->acquiredLocks['shared'][$path]--;
+			}
+		} else if ($type === self::LOCK_EXCLUSIVE) {
+			unset($this->acquiredLocks['exclusive'][$path]);
+		}
+	}
+
+	/**
+	 * Change the type of an existing lock
+	 *
+	 * @param string $path
+	 * @param int $targetType self::LOCK_SHARED or self::LOCK_EXCLUSIVE
+	 */
+	protected function markChange($path, $targetType) {
+		if ($targetType === self::LOCK_SHARED) {
+			unset($this->acquiredLocks['exclusive'][$path]);
+			if (!isset($this->acquiredLocks['shared'][$path])) {
+				$this->acquiredLocks['shared'][$path] = 0;
+			}
+			$this->acquiredLocks['shared'][$path]++;
+		} else if ($targetType === self::LOCK_EXCLUSIVE) {
+			$this->acquiredLocks['exclusive'][$path] = true;
+			$this->acquiredLocks['shared'][$path]--;
+		}
+	}
+
+	/**
+	 * release all lock acquired by this instance
+	 */
+	public function releaseAll() {
+		foreach ($this->acquiredLocks['shared'] as $path => $count) {
+			for ($i = 0; $i < $count; $i++) {
+				$this->releaseLock($path, self::LOCK_SHARED);
+			}
+		}
+
+		foreach ($this->acquiredLocks['exclusive'] as $path => $hasLock) {
+			$this->releaseLock($path, self::LOCK_EXCLUSIVE);
+		}
+	}
+}
diff --git a/lib/private/lock/memcachelockingprovider.php b/lib/private/lock/memcachelockingprovider.php
index 5f2b5e5a4b..871572f7e3 100644
--- a/lib/private/lock/memcachelockingprovider.php
+++ b/lib/private/lock/memcachelockingprovider.php
@@ -23,21 +23,15 @@
 
 namespace OC\Lock;
 
-use OCP\Lock\ILockingProvider;
 use OCP\Lock\LockedException;
 use OCP\IMemcache;
 
-class MemcacheLockingProvider implements ILockingProvider {
+class MemcacheLockingProvider extends AbstractLockingProvider {
 	/**
 	 * @var \OCP\IMemcache
 	 */
 	private $memcache;
 
-	private $acquiredLocks = [
-		'shared' => [],
-		'exclusive' => []
-	];
-
 	/**
 	 * @param \OCP\IMemcache $memcache
 	 */
@@ -71,17 +65,13 @@ class MemcacheLockingProvider implements ILockingProvider {
 			if (!$this->memcache->inc($path)) {
 				throw new LockedException($path);
 			}
-			if (!isset($this->acquiredLocks['shared'][$path])) {
-				$this->acquiredLocks['shared'][$path] = 0;
-			}
-			$this->acquiredLocks['shared'][$path]++;
 		} else {
 			$this->memcache->add($path, 0);
 			if (!$this->memcache->cas($path, 0, 'exclusive')) {
 				throw new LockedException($path);
 			}
-			$this->acquiredLocks['exclusive'][$path] = true;
 		}
+		$this->markAcquire($path, $type);
 	}
 
 	/**
@@ -92,13 +82,12 @@ class MemcacheLockingProvider implements ILockingProvider {
 		if ($type === self::LOCK_SHARED) {
 			if (isset($this->acquiredLocks['shared'][$path]) and $this->acquiredLocks['shared'][$path] > 0) {
 				$this->memcache->dec($path);
-				$this->acquiredLocks['shared'][$path]--;
 				$this->memcache->cad($path, 0);
 			}
 		} else if ($type === self::LOCK_EXCLUSIVE) {
 			$this->memcache->cad($path, 'exclusive');
-			unset($this->acquiredLocks['exclusive'][$path]);
 		}
+		$this->markRelease($path, $type);
 	}
 
 	/**
@@ -113,33 +102,12 @@ class MemcacheLockingProvider implements ILockingProvider {
 			if (!$this->memcache->cas($path, 'exclusive', 1)) {
 				throw new LockedException($path);
 			}
-			unset($this->acquiredLocks['exclusive'][$path]);
-			if (!isset($this->acquiredLocks['shared'][$path])) {
-				$this->acquiredLocks['shared'][$path] = 0;
-			}
-			$this->acquiredLocks['shared'][$path]++;
 		} else if ($targetType === self::LOCK_EXCLUSIVE) {
 			// we can only change a shared lock to an exclusive if there's only a single owner of the shared lock
 			if (!$this->memcache->cas($path, 1, 'exclusive')) {
 				throw new LockedException($path);
 			}
-			$this->acquiredLocks['exclusive'][$path] = true;
-			$this->acquiredLocks['shared'][$path]--;
-		}
-	}
-
-	/**
-	 * release all lock acquired by this instance
-	 */
-	public function releaseAll() {
-		foreach ($this->acquiredLocks['shared'] as $path => $count) {
-			for ($i = 0; $i < $count; $i++) {
-				$this->releaseLock($path, self::LOCK_SHARED);
-			}
-		}
-
-		foreach ($this->acquiredLocks['exclusive'] as $path => $hasLock) {
-			$this->releaseLock($path, self::LOCK_EXCLUSIVE);
 		}
+		$this->markChange($path, $targetType);
 	}
 }
diff --git a/tests/lib/lock/lockingprovider.php b/tests/lib/lock/lockingprovider.php
index efd6e1939f..ca72c1bb7f 100644
--- a/tests/lib/lock/lockingprovider.php
+++ b/tests/lib/lock/lockingprovider.php
@@ -120,6 +120,36 @@ abstract class LockingProvider extends TestCase {
 		$this->assertFalse($this->instance->isLocked('asd', ILockingProvider::LOCK_EXCLUSIVE));
 	}
 
+	public function testReleaseAllAfterChange() {
+		$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
+		$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
+		$this->instance->acquireLock('bar', ILockingProvider::LOCK_SHARED);
+		$this->instance->acquireLock('asd', ILockingProvider::LOCK_EXCLUSIVE);
+
+		$this->instance->changeLock('bar', ILockingProvider::LOCK_EXCLUSIVE);
+
+		$this->instance->releaseAll();
+
+		$this->assertFalse($this->instance->isLocked('foo', ILockingProvider::LOCK_SHARED));
+		$this->assertFalse($this->instance->isLocked('bar', ILockingProvider::LOCK_SHARED));
+		$this->assertFalse($this->instance->isLocked('bar', ILockingProvider::LOCK_EXCLUSIVE));
+		$this->assertFalse($this->instance->isLocked('asd', ILockingProvider::LOCK_EXCLUSIVE));
+	}
+
+	public function testReleaseAllAfterUnlock() {
+		$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
+		$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
+		$this->instance->acquireLock('bar', ILockingProvider::LOCK_SHARED);
+		$this->instance->acquireLock('asd', ILockingProvider::LOCK_EXCLUSIVE);
+
+		$this->instance->releaseLock('bar', ILockingProvider::LOCK_SHARED);
+
+		$this->instance->releaseAll();
+
+		$this->assertFalse($this->instance->isLocked('foo', ILockingProvider::LOCK_SHARED));
+		$this->assertFalse($this->instance->isLocked('asd', ILockingProvider::LOCK_EXCLUSIVE));
+	}
+
 	public function testReleaseAfterReleaseAll() {
 		$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);
 		$this->instance->acquireLock('foo', ILockingProvider::LOCK_SHARED);