diff options
Diffstat (limited to 'src/mongo/db/db_raii.cpp')
| -rw-r--r-- | src/mongo/db/db_raii.cpp | 135 |
1 files changed, 28 insertions, 107 deletions
diff --git a/src/mongo/db/db_raii.cpp b/src/mongo/db/db_raii.cpp index b3e66797bfd..f9544eab063 100644 --- a/src/mongo/db/db_raii.cpp +++ b/src/mongo/db/db_raii.cpp @@ -127,22 +127,11 @@ void assertCollectionChangesCompatibleWithReadTimestamp(OperationContext* opCtx, } /** - * Performs some sanity checks on the collection and database. + * Performs validation of special locking requirements for certain namespaces. */ -void verifyDbAndCollectionReadIntent(OperationContext* opCtx, - LockMode modeColl, - const NamespaceStringOrUUID& nsOrUUID, - const NamespaceString& resolvedNss, - CollectionPtr& coll, - Database* db) { - invariant(!nsOrUUID.uuid() || coll, - str::stream() << "Collection for " << resolvedNss.ns() - << " disappeared after successfully resolving " << nsOrUUID.toString()); - - invariant(!nsOrUUID.uuid() || db, - str::stream() << "Database for " << resolvedNss.ns() - << " disappeared after successfully resolving " << nsOrUUID.toString()); - +void verifyNamespaceLockingRequirements(OperationContext* opCtx, + LockMode modeColl, + const NamespaceString& resolvedNss) { // In most cases we expect modifications for system.views to upgrade MODE_IX to MODE_X before // taking the lock. One exception is a query by UUID of system.views in a transaction. Usual // queries of system.views (by name, not UUID) within a transaction are rejected. However, if @@ -474,32 +463,6 @@ void checkInvariantsForReadOptions(const NamespaceString& nss, } } -/** - * Returns a collection reference compatible with the specified 'readTimestamp'. Creates and places - * a compatible PIT collection reference in the 'catalog' if needed and the collection exists at - * that PIT. - */ -CollectionPtr fetchOrCreatePITCollection(OperationContext* opCtx, - const CollectionCatalog* catalog, - const NamespaceString nss, - boost::optional<Timestamp> readTimestamp, - bool isPrimaryNs) { - if (catalog->needsOpenCollection(opCtx, nss, readTimestamp)) { - // Getting this far means that either the collection is not present in the catalog (it may - // have been dropped) or the read timestamp is earlier than the last DDL operation - // (minValidSnapshot). So try to create a valid past Collection instance for the - // readTimestamp. - (void)catalog->openCollection(opCtx, nss, readTimestamp); - } - - // TODO SERVER-70846: openCollection does not set a yield handler on the CollectionPtr - // returned. Therefore, it is necessary to lookup the collection again via a different - // lookup fn to fetch a yielding-aware CollectionPtr from the catalog. - CollectionPtr coll = catalog->lookupCollectionByNamespace(opCtx, nss); - coll.makeYieldable(opCtx, LockedCollectionYieldRestore{opCtx, coll}); - return coll; -} - } // namespace AutoStatsTracker::AutoStatsTracker( @@ -760,7 +723,6 @@ AutoGetCollectionForReadPITCatalog::AutoGetCollectionForReadPITCatalog( [&](const BSONObj& data) { sleepFor(Milliseconds(data["waitForMillis"].numberInt())); }); auto catalog = CollectionCatalog::get(opCtx); - auto databaseHolder = DatabaseHolder::get(opCtx); _resolvedNss = catalog->resolveNamespaceStringOrUUID(opCtx, nsOrUUID); @@ -780,14 +742,15 @@ AutoGetCollectionForReadPITCatalog::AutoGetCollectionForReadPITCatalog( const auto readSource = opCtx->recoveryUnit()->getTimestampReadSource(); const auto readTimestamp = opCtx->recoveryUnit()->getPointInTimeReadTimestamp(opCtx); - // Check that the collections are all safe to use. First acquire collection from our catalog. - _coll = fetchOrCreatePITCollection( - opCtx, catalog.get(), _resolvedNss, readTimestamp, true /* isPrimaryNs */); + // Check that the collections are all safe to use. First acquire collection from our catalog + // compatible with the specified 'readTimestamp'. Creates and places a compatible PIT collection + // reference in the 'catalog' if needed and the collection exists at that PIT. + _coll = catalog->establishConsistentCollection(opCtx, nsOrUUID, readTimestamp); + _coll.makeYieldable(opCtx, LockedCollectionYieldRestore{opCtx, _coll}); // Validate primary collection. checkCollectionUUIDMismatch(opCtx, _resolvedNss, _coll, options._expectedUUID); - verifyDbAndCollectionReadIntent( - opCtx, modeColl, nsOrUUID, _resolvedNss, _coll, _autoDb.getDb()); + verifyNamespaceLockingRequirements(opCtx, modeColl, _resolvedNss); // Check secondary collections and verify they are valid for use. if (!secondaryNssOrUUIDs.empty()) { @@ -800,18 +763,13 @@ AutoGetCollectionForReadPITCatalog::AutoGetCollectionForReadPITCatalog( if (!_secondaryNssIsAViewOrSharded) { // Ensure that the readTimestamp is compatible with the latest Collection instances or // create PIT instances in the 'catalog' (if the collections existed at that PIT). - for (const auto& secondaryNss : *resolvedSecondaryNamespaces) { - auto secondaryCollectionAtPIT = fetchOrCreatePITCollection( - opCtx, catalog.get(), secondaryNss, readTimestamp, false /* isPrimaryNs */); + for (const auto& secondaryNssOrUUID : secondaryNssOrUUIDs) { + auto secondaryCollectionAtPIT = catalog->establishConsistentCollection( + opCtx, secondaryNssOrUUID, readTimestamp); if (secondaryCollectionAtPIT) { invariant(secondaryCollectionAtPIT->ns().dbName() == _resolvedNss.dbName()); - verifyDbAndCollectionReadIntent( - opCtx, - MODE_IS, - secondaryNss, - secondaryNss, - secondaryCollectionAtPIT, - databaseHolder->getDb(opCtx, secondaryNss.dbName())); + verifyNamespaceLockingRequirements( + opCtx, MODE_IS, secondaryCollectionAtPIT->ns()); } } } @@ -1197,42 +1155,7 @@ std::shared_ptr<const ViewDefinition> lookupView( return view; } -const Collection* getCollectionFromCatalog(OperationContext* opCtx, - const std::shared_ptr<const CollectionCatalog>& catalog, - const NamespaceStringOrUUID& nsOrUUID, - const boost::optional<Timestamp>& readTimestamp) { - if (catalog->needsOpenCollection(opCtx, nsOrUUID, readTimestamp)) { - auto coll = catalog->openCollection(opCtx, nsOrUUID, readTimestamp).get(); - if (coll) { - if (auto capSnap = - CappedSnapshots::get(opCtx).getSnapshot(coll->getRecordStore()->getIdent())) { - // The only way openCollection can be required for a collection that uses capped - // snapshots (i.e. a collection that is unreplicated and capped) is: - // * The present read operation is reading without a timestamp (since unreplicated - // collections don't support timestamped reads), and - // * When opening the storage snapshot (and thus when establishing the capped - // snapshot), there was a DDL operation pending on the namespace or UUID - // requested for this read (because this is the only time openCollection is - // called for an untimestamped read). - // - // Because DDL operations require a collection X lock, there cannot have been any - // ongoing concurrent writes to the collection while establishing the capped - // snapshot. This means that if there was a capped snapshot, it should not have - // contained any uncommitted writes, and so the _lowestUncommittedRecord must be - // null. - invariant(!capSnap->hasUncommittedRecords()); - } - } - return coll; - } else { - // It's safe to extract the raw pointer from the CollectionPtr returned by lookupCollection - // because it is owned by the catalog, which will remain valid for as long as we're using - // the collection returned here. - return catalog->lookupCollectionByNamespaceOrUUID(opCtx, nsOrUUID).get(); - } -} - -std::tuple<NamespaceString, const Collection*, std::shared_ptr<const ViewDefinition>> +std::tuple<NamespaceString, CollectionPtr, std::shared_ptr<const ViewDefinition>> getCollectionForLockFreeRead(OperationContext* opCtx, const std::shared_ptr<const CollectionCatalog>& catalog, boost::optional<Timestamp> readTimestamp, @@ -1250,8 +1173,11 @@ getCollectionForLockFreeRead(OperationContext* opCtx, opCtx->getLogicalSessionId()->getId() == UUID::fromCDR(data["lsid"].uuid()); }); - auto coll = getCollectionFromCatalog(opCtx, catalog, nsOrUUID, readTimestamp); + // Returns a collection reference compatible with the specified 'readTimestamp'. Creates and + // places a compatible PIT collection reference in the 'catalog' if needed and the collection + // exists at that PIT. + CollectionPtr coll = catalog->establishConsistentCollection(opCtx, nsOrUUID, readTimestamp); // TODO (SERVER-71222): This is broken if the UUID doesn't exist in the latest catalog. // // Note: This call to resolveNamespaceStringOrUUID must happen after getCollectionFromCatalog @@ -1260,7 +1186,9 @@ getCollectionForLockFreeRead(OperationContext* opCtx, const auto nss = catalog->resolveNamespaceStringOrUUID(opCtx, nsOrUUID); checkCollectionUUIDMismatch(opCtx, catalog, nss, coll, options._expectedUUID); - return {nss, coll, coll ? nullptr : lookupView(opCtx, catalog, nss, options._viewMode)}; + std::shared_ptr<const ViewDefinition> viewDefinition = + coll ? nullptr : lookupView(opCtx, catalog, nss, options._viewMode); + return {nss, std::move(coll), std::move(viewDefinition)}; } static const Lock::GlobalLockSkipOptions kLockFreeReadsGlobalLockOptions{[] { @@ -1269,16 +1197,11 @@ static const Lock::GlobalLockSkipOptions kLockFreeReadsGlobalLockOptions{[] { return options; }()}; -CollectionPtr makeCollectionPtrForLockFreeReadSubOperation(OperationContext* opCtx, - const Collection* coll) { - return {coll}; -} - struct CatalogStateForNamespace { std::shared_ptr<const CollectionCatalog> catalog; bool isAnySecondaryNssShardedOrAView; NamespaceString resolvedNss; - const Collection* collection; + CollectionPtr collection; std::shared_ptr<const ViewDefinition> view; }; @@ -1300,7 +1223,7 @@ CatalogStateForNamespace acquireCatalogStateForNamespace( getCollectionForLockFreeRead(opCtx, catalog, readTimestamp, nsOrUUID, options); return CatalogStateForNamespace{ - catalog, isAnySecondaryNssShardedOrAView, resolvedNss, collection, view}; + catalog, isAnySecondaryNssShardedOrAView, resolvedNss, std::move(collection), view}; } boost::optional<ShouldNotConflictWithSecondaryBatchApplicationBlock> @@ -1339,7 +1262,7 @@ CollectionPtr::RestoreFn AutoGetCollectionForReadLockFreePITCatalog::_makeRestor _view = catalogStateForNamespace.view; _catalogStasher.stash(std::move(catalogStateForNamespace.catalog)); - return catalogStateForNamespace.collection; + return catalogStateForNamespace.collection.get(); } catch (const ExceptionFor<ErrorCodes::NamespaceNotFound>&) { // Calls to CollectionCatalog::resolveNamespaceStringOrUUID (called from // acquireCatalogStateForNamespace) will result in a NamespaceNotFound error if the @@ -1397,7 +1320,7 @@ AutoGetCollectionForReadLockFreePITCatalog::AutoGetCollectionForReadLockFreePITC if (_view) { _lockFreeReadsBlock.reset(); } - _collectionPtr = makeCollectionPtrForLockFreeReadSubOperation(opCtx, collection); + _collectionPtr = std::move(collection); } else { auto catalogStateForNamespace = acquireCatalogStateForNamespace(opCtx, @@ -1415,9 +1338,7 @@ AutoGetCollectionForReadLockFreePITCatalog::AutoGetCollectionForReadLockFreePITC _catalogStasher.stash(std::move(catalogStateForNamespace.catalog)); _secondaryNssIsAViewOrSharded = catalogStateForNamespace.isAnySecondaryNssShardedOrAView; - _collectionPtr = CollectionPtr( - - catalogStateForNamespace.collection); + _collectionPtr = std::move(catalogStateForNamespace.collection); _collectionPtr.makeYieldable( opCtx, _makeRestoreFromYieldFn(options, |