Merge pull request #51920 from nextcloud/newfolder-race-improvements

fix: improve handling of newFolder race condition handling

Author: come-nc

lib/private/Files/Node/Folder.php

@@ -126,8 +126,21 @@ public function newFolder($path) {
 			$fullPath = $this->getFullPath($path);
 			$nonExisting = new NonExistingFolder($this->root, $this->view, $fullPath);
 			$this->sendHooks(['preWrite', 'preCreate'], [$nonExisting]);
-			if (!$this->view->mkdir($fullPath) && !$this->view->is_dir($fullPath)) {
-				throw new NotPermittedException('Could not create folder "' . $fullPath . '"');
+			if (!$this->view->mkdir($fullPath)) {
+				// maybe another concurrent process created the folder already
+				if (!$this->view->is_dir($fullPath)) {
+					throw new NotPermittedException('Could not create folder "' . $fullPath . '"');
+				} else {
+					// we need to ensure we don't return before the concurrent request has finished updating the cache
+					$tries = 5;
+					while (!$this->view->getFileInfo($fullPath)) {
+						if ($tries < 1) {
+							throw new NotPermittedException('Could not create folder "' . $fullPath . '", folder exists but unable to get cache entry');
+						}
+						usleep(5 * 1000);
+						$tries--;
+					}
+				}
 			}
 			$parent = dirname($fullPath) === $this->getPath() ? $this : null;
 			$node = new Folder($this->root, $this->view, $fullPath, null, $parent);