From 704f515175c0001ae11a949571445eacf4962242 Mon Sep 17 00:00:00 2001
From: Roeland Jago Douma <roeland@famdouma.nl>
Date: Mon, 31 Aug 2020 12:25:20 +0200
Subject: [PATCH 1/2] Don't lose filecache entry on s3 overwrite error

If the object store errors we should not always delete the filecache
entry. As this might lead to people losing access to their files.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>
---
 .../Files/ObjectStore/ObjectStoreStorage.php  | 21 ++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/lib/private/Files/ObjectStore/ObjectStoreStorage.php b/lib/private/Files/ObjectStore/ObjectStoreStorage.php
index a5112bcbba..b2ec094a71 100644
--- a/lib/private/Files/ObjectStore/ObjectStoreStorage.php
+++ b/lib/private/Files/ObjectStore/ObjectStoreStorage.php
@@ -465,11 +465,22 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 				$this->objectStore->writeObject($urn, $stream);
 			}
 		} catch (\Exception $ex) {
-			$this->getCache()->remove($uploadPath);
-			$this->logger->logException($ex, [
-				'app' => 'objectstore',
-				'message' => 'Could not create object ' . $urn . ' for ' . $path,
-			]);
+			if (!$exists) {
+				/*
+				 * Only remove the entry if we are dealing with a new file.
+				 * Else people lose access to existing files
+				 */
+				$this->getCache()->remove($uploadPath);
+				$this->logger->logException($ex, [
+					'app' => 'objectstore',
+					'message' => 'Could not create object ' . $urn . ' for ' . $path,
+				]);
+			} else {
+				$this->logger->logException($ex, [
+					'app' => 'objectstore',
+					'message' => 'Could not update object ' . $urn . ' for ' . $path,
+				]);
+			}
 			throw $ex; // make this bubble up
 		}
 

From 952ec3370e2f096f9489863edc8c48842e3fd8af Mon Sep 17 00:00:00 2001
From: Roeland Jago Douma <roeland@famdouma.nl>
Date: Mon, 31 Aug 2020 12:28:04 +0200
Subject: [PATCH 2/2] Only update the filecache entry once the file has been
 written to S3

If we already update before we have no way to revert if the upload
fails.

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>
---
 .../Files/ObjectStore/ObjectStoreStorage.php        | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/lib/private/Files/ObjectStore/ObjectStoreStorage.php b/lib/private/Files/ObjectStore/ObjectStoreStorage.php
index b2ec094a71..faa0342935 100644
--- a/lib/private/Files/ObjectStore/ObjectStoreStorage.php
+++ b/lib/private/Files/ObjectStore/ObjectStoreStorage.php
@@ -446,7 +446,13 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 
 		$exists = $this->getCache()->inCache($path);
 		$uploadPath = $exists ? $path : $path . '.part';
-		$fileId = $this->getCache()->put($uploadPath, $stat);
+
+		if ($exists) {
+			$fileId = $stat['fileid'];
+		} else {
+			$fileId = $this->getCache()->put($uploadPath, $stat);
+		}
+
 		$urn = $this->getURN($fileId);
 		try {
 			//upload to object storage
@@ -461,6 +467,7 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 				if (is_resource($countStream)) {
 					fclose($countStream);
 				}
+				$stat['size'] = $size;
 			} else {
 				$this->objectStore->writeObject($urn, $stream);
 			}
@@ -484,7 +491,9 @@ class ObjectStoreStorage extends \OC\Files\Storage\Common {
 			throw $ex; // make this bubble up
 		}
 
-		if (!$exists) {
+		if ($exists) {
+			$this->getCache()->update($fileId, $stat);
+		} else {
 			if ($this->objectStore->objectExists($urn)) {
 				$this->getCache()->move($uploadPath, $path);
 			} else {