From 747f5d256395e42745dc3d0d10f1a102f2570ef3 Mon Sep 17 00:00:00 2001 From: Carl Schwan Date: Fri, 6 Feb 2026 12:09:18 +0100 Subject: [PATCH 1/2] fix(propagator): Improve lock behavior of propagator Fix possible dead locks when running the propagator caused by two requests updating the same amount rows in transactions. - Lock rows always in the same deterministic order by sorting the path_hash first - On all database outside of sqlite, also do first a SELECT FOR UPDATE to lock all the rows used in batch UPDATE calls, afterward to decrease the risk of two requests trying to lock the same rows Signed-off-by: Carl Schwan --- lib/composer/composer/autoload_classmap.php | 1 + lib/composer/composer/autoload_static.php | 1 + .../DB/QueryBuilder/ExtendedQueryBuilder.php | 6 +++++ lib/private/DB/QueryBuilder/QueryBuilder.php | 10 +++++++ lib/private/Files/Cache/Propagator.php | 1 + .../QueryBuilder/ConflictResolutionMode.php | 26 +++++++++++++++++++ lib/public/DB/QueryBuilder/IQueryBuilder.php | 8 ++++++ tests/lib/Files/Cache/PropagatorTest.php | 3 +-- 8 files changed, 54 insertions(+), 2 deletions(-) create mode 100644 lib/public/DB/QueryBuilder/ConflictResolutionMode.php diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php index b7209606baf32..aa548470e07d0 100644 --- a/lib/composer/composer/autoload_classmap.php +++ b/lib/composer/composer/autoload_classmap.php @@ -311,6 +311,7 @@ 'OCP\\DB\\IPreparedStatement' => $baseDir . '/lib/public/DB/IPreparedStatement.php', 'OCP\\DB\\IResult' => $baseDir . '/lib/public/DB/IResult.php', 'OCP\\DB\\ISchemaWrapper' => $baseDir . '/lib/public/DB/ISchemaWrapper.php', + 'OCP\\DB\\QueryBuilder\\ConflictResolutionMode' => $baseDir . '/lib/public/DB/QueryBuilder/ConflictResolutionMode.php', 'OCP\\DB\\QueryBuilder\\ICompositeExpression' => $baseDir . '/lib/public/DB/QueryBuilder/ICompositeExpression.php', 'OCP\\DB\\QueryBuilder\\IExpressionBuilder' => $baseDir . '/lib/public/DB/QueryBuilder/IExpressionBuilder.php', 'OCP\\DB\\QueryBuilder\\IFunctionBuilder' => $baseDir . '/lib/public/DB/QueryBuilder/IFunctionBuilder.php', diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php index 7409cdf224d11..75bcc8d69de9a 100644 --- a/lib/composer/composer/autoload_static.php +++ b/lib/composer/composer/autoload_static.php @@ -352,6 +352,7 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2 'OCP\\DB\\IPreparedStatement' => __DIR__ . '/../../..' . '/lib/public/DB/IPreparedStatement.php', 'OCP\\DB\\IResult' => __DIR__ . '/../../..' . '/lib/public/DB/IResult.php', 'OCP\\DB\\ISchemaWrapper' => __DIR__ . '/../../..' . '/lib/public/DB/ISchemaWrapper.php', + 'OCP\\DB\\QueryBuilder\\ConflictResolutionMode' => __DIR__ . '/../../..' . '/lib/public/DB/QueryBuilder/ConflictResolutionMode.php', 'OCP\\DB\\QueryBuilder\\ICompositeExpression' => __DIR__ . '/../../..' . '/lib/public/DB/QueryBuilder/ICompositeExpression.php', 'OCP\\DB\\QueryBuilder\\IExpressionBuilder' => __DIR__ . '/../../..' . '/lib/public/DB/QueryBuilder/IExpressionBuilder.php', 'OCP\\DB\\QueryBuilder\\IFunctionBuilder' => __DIR__ . '/../../..' . '/lib/public/DB/QueryBuilder/IFunctionBuilder.php', diff --git a/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php b/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php index f928132a123a8..c017412cd180b 100644 --- a/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php +++ b/lib/private/DB/QueryBuilder/ExtendedQueryBuilder.php @@ -10,6 +10,7 @@ use OC\DB\Exceptions\DbalException; use OCP\DB\IResult; +use OCP\DB\QueryBuilder\ConflictResolutionMode; use OCP\DB\QueryBuilder\IQueryBuilder; use OCP\IDBConnection; @@ -306,4 +307,9 @@ public function getOutputColumns(): array { public function prefixTableName(string $table): string { return $this->builder->prefixTableName($table); } + + public function forUpdate(ConflictResolutionMode $conflictResolutionMode = ConflictResolutionMode::Ordinary): self { + $this->builder->forUpdate($conflictResolutionMode); + return $this; + } } diff --git a/lib/private/DB/QueryBuilder/QueryBuilder.php b/lib/private/DB/QueryBuilder/QueryBuilder.php index ea93e57d80d40..9fac22bb181e2 100644 --- a/lib/private/DB/QueryBuilder/QueryBuilder.php +++ b/lib/private/DB/QueryBuilder/QueryBuilder.php @@ -20,12 +20,14 @@ use OC\DB\QueryBuilder\FunctionBuilder\SqliteFunctionBuilder; use OC\SystemConfig; use OCP\DB\IResult; +use OCP\DB\QueryBuilder\ConflictResolutionMode; use OCP\DB\QueryBuilder\ICompositeExpression; use OCP\DB\QueryBuilder\ILiteral; use OCP\DB\QueryBuilder\IParameter; use OCP\DB\QueryBuilder\IQueryBuilder; use OCP\DB\QueryBuilder\IQueryFunction; use OCP\IDBConnection; +use Override; use Psr\Log\LoggerInterface; class QueryBuilder implements IQueryBuilder { @@ -1404,4 +1406,12 @@ public function runAcrossAllShards(): self { return $this; } + #[Override] + public function forUpdate(ConflictResolutionMode $conflictResolutionMode = ConflictResolutionMode::Ordinary): self { + match ($conflictResolutionMode) { + ConflictResolutionMode::Ordinary => $this->queryBuilder->forUpdate(), + ConflictResolutionMode::SkipLocked => $this->queryBuilder->forUpdate(\Doctrine\DBAL\Query\ForUpdate\ConflictResolutionMode::SKIP_LOCKED), + }; + return $this; + } } diff --git a/lib/private/Files/Cache/Propagator.php b/lib/private/Files/Cache/Propagator.php index a6ba87896f4de..a200d00a31238 100644 --- a/lib/private/Files/Cache/Propagator.php +++ b/lib/private/Files/Cache/Propagator.php @@ -77,6 +77,7 @@ public function propagateChange($internalPath, $time, $sizeDifference = 0) { } $parentHashes = array_map('md5', $parents); + sort($parentHashes); // Ensure rows are always locked in the same order $etag = uniqid(); // since we give all folders the same etag we don't ask the storage for the etag $builder = $this->connection->getQueryBuilder(); diff --git a/lib/public/DB/QueryBuilder/ConflictResolutionMode.php b/lib/public/DB/QueryBuilder/ConflictResolutionMode.php new file mode 100644 index 0000000000000..56a59b39099c4 --- /dev/null +++ b/lib/public/DB/QueryBuilder/ConflictResolutionMode.php @@ -0,0 +1,26 @@ + Date: Fri, 6 Feb 2026 16:13:44 +0100 Subject: [PATCH 2/2] fix(propagator): Lock rows also in propagateChange Signed-off-by: Carl Schwan [skip ci] --- lib/private/Files/Cache/Propagator.php | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/lib/private/Files/Cache/Propagator.php b/lib/private/Files/Cache/Propagator.php index a200d00a31238..d0ae8a94f2242 100644 --- a/lib/private/Files/Cache/Propagator.php +++ b/lib/private/Files/Cache/Propagator.php @@ -9,6 +9,7 @@ use OC\DB\Exceptions\DbalException; use OC\Files\Storage\Wrapper\Encryption; +use OCP\DB\QueryBuilder\ILiteral; use OCP\DB\QueryBuilder\IQueryBuilder; use OCP\Files\Cache\IPropagator; use OCP\Files\Storage\IReliableEtagStorage; @@ -81,9 +82,7 @@ public function propagateChange($internalPath, $time, $sizeDifference = 0) { $etag = uniqid(); // since we give all folders the same etag we don't ask the storage for the etag $builder = $this->connection->getQueryBuilder(); - $hashParams = array_map(function ($hash) use ($builder) { - return $builder->expr()->literal($hash); - }, $parentHashes); + $hashParams = array_map(static fn (string $hash): ILiteral => $builder->expr()->literal($hash), $parentHashes); $builder->update('filecache') ->set('mtime', $builder->func()->greatest('mtime', $builder->createNamedParameter($time, IQueryBuilder::PARAM_INT))) @@ -124,9 +123,27 @@ public function propagateChange($internalPath, $time, $sizeDifference = 0) { for ($i = 0; $i < self::MAX_RETRIES; $i++) { try { - $builder->executeStatement(); + if ($this->connection->getDatabaseProvider() !== IDBConnection::PLATFORM_SQLITE) { + $this->connection->beginTransaction(); + // Lock all the rows first with a SELECT FOR UPDATE ordered by path_hash + $forUpdate = $this->connection->getQueryBuilder(); + $forUpdate->select('fileid') + ->from('filecache') + ->where($forUpdate->expr()->eq('storage', $forUpdate->createNamedParameter($storageId, IQueryBuilder::PARAM_INT))) + ->andWhere($forUpdate->expr()->in('path_hash', $hashParams)) + ->orderBy('path_hash') + ->forUpdate() + ->executeQuery(); + $builder->executeStatement(); + $this->connection->commit(); + } else { + $builder->executeStatement(); + } break; } catch (DbalException $e) { + if ($this->connection->getDatabaseProvider() !== IDBConnection::PLATFORM_SQLITE) { + $this->connection->rollBack(); + } if (!$e->isRetryable()) { throw $e; }