re-acquired expired shared locks on large file uploads

during large file uploads, the shared lock that we get at the begining can expire
leading to locked errors later on, instead of erroring, try to re-get the lock

Signed-off-by: Robin Appelman <robin@icewind.nl>

diff --git a/apps/dav/lib/Connector/Sabre/File.php b/apps/dav/lib/Connector/Sabre/File.php
index 0767fc9550e84e055b2a3816aad028595b06a8b0..e98ecf5b0a4ea1194589b22dfedfbf4fb28bf5b9 100644 (file)
--- a/apps/dav/lib/Connector/Sabre/File.php
+++ b/apps/dav/lib/Connector/Sabre/File.php
@@ -252,10 +252,22 @@ class File extends Node implements IFile {
                                try {
                                        $this->changeLock(ILockingProvider::LOCK_EXCLUSIVE);
                                } catch (LockedException $e) {
-                                       if ($needsPartFile) {
-                                               $partStorage->unlink($internalPartPath);
+                                       // during very large uploads, the shared lock we got at the start might have been expired
+                                       // meaning that the above lock can fail not just only because somebody else got a shared lock
+                                       // or because there is no existing shared lock to make exclusive
+                                       //
+                                       // Thus we try to get a new exclusive lock, if the original lock failed because of a different shared
+                                       // lock this will still fail, if our original shared lock expired the new lock will be successful and
+                                       // the entire operation will be safe
+
+                                       try {
+                                               $this->acquireLock(ILockingProvider::LOCK_EXCLUSIVE);
+                                       } catch (LockedException $e) {
+                                               if ($needsPartFile) {
+                                                       $partStorage->unlink($internalPartPath);
+                                               }
+                                               throw new FileLocked($e->getMessage(), $e->getCode(), $e);
                                        }
-                                       throw new FileLocked($e->getMessage(), $e->getCode(), $e);
                                }
 
                                // rename to correct path

diff --git a/apps/dav/tests/unit/Connector/Sabre/FileTest.php b/apps/dav/tests/unit/Connector/Sabre/FileTest.php
index 3e3e80f752510bcaecb397142237e1c0824cdd6a..c579a904260bed711d55b99b3dc87a9b809aa189 100644 (file)
--- a/apps/dav/tests/unit/Connector/Sabre/FileTest.php
+++ b/apps/dav/tests/unit/Connector/Sabre/FileTest.php
@@ -1201,4 +1201,25 @@ class FileTest extends TestCase {
 
                $this->assertEquals('new content', $view->file_get_contents('root/file.txt'));
        }
+
+       public function testPutLockExpired() {
+               $view = new \OC\Files\View('/' . $this->user . '/files/');
+
+               $path = 'test-locking.txt';
+               $info = new \OC\Files\FileInfo(
+                       '/' . $this->user . '/files/' . $path,
+                       $this->getMockStorage(),
+                       null,
+                       ['permissions' => \OCP\Constants::PERMISSION_ALL],
+                       null
+               );
+
+               $file = new \OCA\DAV\Connector\Sabre\File($view, $info);
+
+               // don't lock before the PUT to simulate an expired shared lock
+               $this->assertNotEmpty($file->put($this->getStream('test data')));
+
+               // afterMethod unlocks
+               $view->unlockFile($path, ILockingProvider::LOCK_SHARED);
+       }
 }