From 449d099bd3f1d666472dd5753355ec48be16a1be Mon Sep 17 00:00:00 2001
From: Andras Bacsai <5845193+andrasbacsai@users.noreply.github.com>
Date: Fri, 16 Oct 2026 22:41:15 +0200
Subject: [PATCH] fix(backups): accept tar exit code 1 in volume backups

GNU tar exits with 1 when a file changes while it is read. The archive
is still valid, so only exit codes above 1 fail the backup.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 app/Jobs/VolumeBackupJob.php       | 13 ++++++++++---
 tests/Feature/VolumeBackupTest.php | 19 +++++++++++++++++++
 2 files changed, 29 insertions(+), 3 deletions(-)

diff --git a/app/Jobs/VolumeBackupJob.php b/app/Jobs/VolumeBackupJob.php
index 6d39ce6b42..0bf27ad35f 100644
--- a/app/Jobs/VolumeBackupJob.php
+++ b/app/Jobs/VolumeBackupJob.php
@@ -92,8 +92,7 @@ class VolumeBackupJob implements ShouldBeEncrypted, ShouldQueue
                 ? 'docker volume inspect '.escapeshellarg($source).' >/dev/null'
                 : 'test -d '.escapeshellarg($source);
 
-            $compressorCommand = BackupCompression::compressorCommand($compressionCpuPercentage);
-            $archiveScript = "compressor=\$({$compressorCommand}); tar -I \"\$compressor\" -cf - -C /volume .";
+            $archiveScript = self::archiveScript($compressionCpuPercentage);
             if ($streamToS3) {
                 $this->execution->update(['local_storage_deleted' => true]);
                 $archiveCommand = $this->streamToS3Command($archiveScript, $backupLocation, $source, $containerName, $image);
@@ -289,8 +288,16 @@ class VolumeBackupJob implements ShouldBeEncrypted, ShouldQueue
     }
 
     /**
-     * @return array<int, string>
+     * GNU tar exits with 1 when a file changes while it is read (for example, an app that writes to the volume
+     * during a live backup). The archive is still valid, so only exit codes above 1 fail the backup.
      */
+    public static function archiveScript(int $compressionCpuPercentage): string
+    {
+        $compressorCommand = BackupCompression::compressorCommand($compressionCpuPercentage);
+
+        return "compressor=\$({$compressorCommand}); { tar -I \"\$compressor\" -cf - -C /volume . || { status=\$?; [ \$status -eq 1 ] || exit \$status; }; }";
+    }
+
     /**
      * Containers can exit and be removed (e.g. `--rm` backup helpers) between `docker ps` and
      * `docker inspect`. Skip those, but still fail when an existing container cannot be inspected.
diff --git a/tests/Feature/VolumeBackupTest.php b/tests/Feature/VolumeBackupTest.php
index 02b8676e11..4938287315 100644
--- a/tests/Feature/VolumeBackupTest.php
+++ b/tests/Feature/VolumeBackupTest.php
@@ -2969,3 +2969,22 @@ it('records a missed volume backup that is too old to run late as a failed execu
     Notification::assertSentToTimes($team, BackupFailed::class, 1);
     Notification::assertSentTo($team, BackupFailed::class, fn (BackupFailed $notification) => $notification->output === 'Skipped: the queued job did not start within 60 minutes.');
 });
+
+it('fails the volume archive only on fatal tar errors', function (int $tarExitCode, int $expectedExitCode) {
+    $bin = sys_get_temp_dir().'/volume-backup-tar-'.uniqid();
+    mkdir($bin);
+    file_put_contents($bin.'/tar', "#!/bin/sh\nexit {$tarExitCode}\n");
+    chmod($bin.'/tar', 0755);
+
+    $result = Process::env(['PATH' => $bin.':/usr/bin:/bin'])
+        ->run(['sh', '-c', VolumeBackupJob::archiveScript(50)]);
+
+    unlink($bin.'/tar');
+    rmdir($bin);
+
+    expect($result->exitCode())->toBe($expectedExitCode);
+})->with([
+    'success' => [0, 0],
+    'file changed as we read it' => [1, 0],
+    'fatal error' => [2, 2],
+]);