From 78b3a418afe15540cbff56d7b57f26286564e753 Mon Sep 17 00:00:00 2001
From: Robin Appelman <robin@icewind.nl>
Date: Tue, 6 Sep 2022 15:05:11 +0200
Subject: [PATCH] enable locking for upload chunks

Signed-off-by: Robin Appelman <robin@icewind.nl>
---
 apps/dav/lib/Connector/Sabre/Directory.php | 19 +++++++++++++++++--
 lib/private/Files/View.php                 |  6 +++---
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/apps/dav/lib/Connector/Sabre/Directory.php b/apps/dav/lib/Connector/Sabre/Directory.php
index b575a051b2a..fa87aa1dd21 100644
--- a/apps/dav/lib/Connector/Sabre/Directory.php
+++ b/apps/dav/lib/Connector/Sabre/Directory.php
@@ -144,9 +144,24 @@ class Directory extends \OCA\DAV\Connector\Sabre\Node implements \Sabre\DAV\ICol
 			}
 			$node = new \OCA\DAV\Connector\Sabre\File($this->fileView, $info);
 
-			// only allow 1 process to upload a file at once but still allow reading the file while writing the part file
+
+			/** @var LoggerInterface $logger */
+			$logger = \OC::$server->get(LoggerInterface::class);
+
+			// we get a shared lock on the file being uploaded and an exclusive lock on a virtual '.upload.part' file.
+			//
+			// The shared lock prevents writes or deletes during the upload while still allowing reading the file.
+			// The exclusive lock stops concurrent upload requests.
+			//
+			// Additionally, the shared lock will be changed into an exclusive one for the actual file write
 			$node->acquireLock(ILockingProvider::LOCK_SHARED);
-			$this->fileView->lockFile($path . '.upload.part', ILockingProvider::LOCK_EXCLUSIVE);
+			try {
+				$logger->debug("Getting lock for upload: $path");
+				$this->fileView->lockFile($path . '.upload.part', ILockingProvider::LOCK_EXCLUSIVE);
+			} catch (LockedException $e) {
+				$logger->error("Failed to acquire lock for upload: $path", ['exception' => $e]);
+				throw $e;
+			}
 
 			$result = $node->put($data);
 
diff --git a/lib/private/Files/View.php b/lib/private/Files/View.php
index e5394e72ffe..51eff754cb1 100644
--- a/lib/private/Files/View.php
+++ b/lib/private/Files/View.php
@@ -1957,7 +1957,7 @@ class View {
 			} catch (LockedException $e) {
 				// rethrow with the a human-readable path
 				throw new LockedException(
-					$this->getPathRelativeToFiles($absolutePath),
+					$this->getRelativePath($absolutePath),
 					$e,
 					$e->getExistingLock()
 				);
@@ -2000,7 +2000,7 @@ class View {
 				try {
 					// rethrow with the a human-readable path
 					throw new LockedException(
-						$this->getPathRelativeToFiles($absolutePath),
+						$this->getRelativePath($absolutePath),
 						$e,
 						$e->getExistingLock()
 					);
@@ -2115,7 +2115,7 @@ class View {
 		$pathSegments = explode('/', $path);
 		if (isset($pathSegments[2])) {
 			// E.g.: /username/files/path-to-file
-			return ($pathSegments[2] === 'files') && (count($pathSegments) > 3);
+			return ($pathSegments[2] === 'files' || $pathSegments[2] === 'uploads') && (count($pathSegments) > 3);
 		}
 
 		return strpos($path, '/appdata_') !== 0;