From c0e17bbe1bfbfdb93b7ab6baffc4a53d94ad7937 Mon Sep 17 00:00:00 2001 From: Neil Alexander Date: Fri, 9 Sep 2022 13:13:04 +0100 Subject: [PATCH] Fix transactions around assigning NIDs --- .../storage/shared/membership_updater.go | 6 +-- roomserver/storage/shared/storage.go | 44 ++++++++++++------- 2 files changed, 30 insertions(+), 20 deletions(-) diff --git a/roomserver/storage/shared/membership_updater.go b/roomserver/storage/shared/membership_updater.go index 07fb697f9..f9c889cb1 100644 --- a/roomserver/storage/shared/membership_updater.go +++ b/roomserver/storage/shared/membership_updater.go @@ -26,11 +26,11 @@ func NewMembershipUpdater( var targetUserNID types.EventStateKeyNID var err error err = d.Writer.Do(d.DB, txn, func(txn *sql.Tx) error { - roomNID, err = d.assignRoomNID(ctx, roomID, roomVersion) + roomNID, err = d.assignRoomNID(ctx, txn, roomID, roomVersion) if err != nil { return err } - targetUserNID, err = d.assignStateKeyNID(ctx, targetUserID) + targetUserNID, err = d.assignStateKeyNID(ctx, txn, targetUserID) if err != nil { return err } @@ -101,7 +101,7 @@ func (u *MembershipUpdater) Update(newMembership tables.MembershipState, event * var inserted bool // Did the query result in a membership change? var retired []string // Did we retire any updates in the process? return inserted, retired, u.d.Writer.Do(u.d.DB, u.txn, func(txn *sql.Tx) error { - senderUserNID, err := u.d.assignStateKeyNID(u.ctx, event.Sender()) + senderUserNID, err := u.d.assignStateKeyNID(u.ctx, u.txn, event.Sender()) if err != nil { return fmt.Errorf("u.d.AssignStateKeyNID: %w", err) } diff --git a/roomserver/storage/shared/storage.go b/roomserver/storage/shared/storage.go index f35592a76..00a17e5cb 100644 --- a/roomserver/storage/shared/storage.go +++ b/roomserver/storage/shared/storage.go @@ -402,7 +402,7 @@ func (d *Database) RemoveRoomAlias(ctx context.Context, alias string) error { func (d *Database) GetMembership(ctx context.Context, roomNID types.RoomNID, requestSenderUserID string) (membershipEventNID types.EventNID, stillInRoom, isRoomforgotten bool, err error) { var requestSenderUserNID types.EventStateKeyNID err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error { - requestSenderUserNID, err = d.assignStateKeyNID(ctx, requestSenderUserID) + requestSenderUserNID, err = d.assignStateKeyNID(ctx, txn, requestSenderUserID) return err }) if err != nil { @@ -596,7 +596,9 @@ func (d *Database) storeEvent( if updater != nil && updater.txn != nil { txn = updater.txn } - err = d.Writer.Do(d.DB, txn, func(txn *sql.Tx) error { + // First writer is with a database-provided transaction, so that NIDs are assigned + // globally outside of the updater context, to help avoid races. + err = d.Writer.Do(d.DB, nil, func(txn *sql.Tx) error { // TODO: Here we should aim to have two different code paths for new rooms // vs existing ones. @@ -611,11 +613,11 @@ func (d *Database) storeEvent( return fmt.Errorf("extractRoomVersionFromCreateEvent: %w", err) } - if roomNID, err = d.assignRoomNID(ctx, event.RoomID(), roomVersion); err != nil { + if roomNID, err = d.assignRoomNID(ctx, txn, event.RoomID(), roomVersion); err != nil { return fmt.Errorf("d.assignRoomNID: %w", err) } - if eventTypeNID, err = d.assignEventTypeNID(ctx, event.Type()); err != nil { + if eventTypeNID, err = d.assignEventTypeNID(ctx, txn, event.Type()); err != nil { return fmt.Errorf("d.assignEventTypeNID: %w", err) } @@ -623,11 +625,19 @@ func (d *Database) storeEvent( // Assigned a numeric ID for the state_key if there is one present. // Otherwise set the numeric ID for the state_key to 0. if eventStateKey != nil { - if eventStateKeyNID, err = d.assignStateKeyNID(ctx, *eventStateKey); err != nil { + if eventStateKeyNID, err = d.assignStateKeyNID(ctx, txn, *eventStateKey); err != nil { return fmt.Errorf("d.assignStateKeyNID: %w", err) } } + return nil + }) + if err != nil { + return 0, 0, types.StateAtEvent{}, nil, "", fmt.Errorf("d.Writer.Do: %w", err) + } + // Second writer is using the database-provided transaction, probably from the + // room updater, for easy roll-back if required. + err = d.Writer.Do(d.DB, txn, func(txn *sql.Tx) error { if eventNID, stateNID, err = d.EventsTable.InsertEvent( ctx, txn, @@ -749,48 +759,48 @@ func (d *Database) MissingAuthPrevEvents( } func (d *Database) assignRoomNID( - ctx context.Context, roomID string, roomVersion gomatrixserverlib.RoomVersion, + ctx context.Context, txn *sql.Tx, roomID string, roomVersion gomatrixserverlib.RoomVersion, ) (types.RoomNID, error) { // Check if we already have a numeric ID in the database. - roomNID, err := d.RoomsTable.SelectRoomNID(ctx, nil, roomID) + roomNID, err := d.RoomsTable.SelectRoomNID(ctx, txn, roomID) if err == sql.ErrNoRows { // We don't have a numeric ID so insert one into the database. - roomNID, err = d.RoomsTable.InsertRoomNID(ctx, nil, roomID, roomVersion) + roomNID, err = d.RoomsTable.InsertRoomNID(ctx, txn, roomID, roomVersion) if err == sql.ErrNoRows { // We raced with another insert so run the select again. - roomNID, err = d.RoomsTable.SelectRoomNID(ctx, nil, roomID) + roomNID, err = d.RoomsTable.SelectRoomNID(ctx, txn, roomID) } } return roomNID, err } func (d *Database) assignEventTypeNID( - ctx context.Context, eventType string, + ctx context.Context, txn *sql.Tx, eventType string, ) (types.EventTypeNID, error) { // Check if we already have a numeric ID in the database. - eventTypeNID, err := d.EventTypesTable.SelectEventTypeNID(ctx, nil, eventType) + eventTypeNID, err := d.EventTypesTable.SelectEventTypeNID(ctx, txn, eventType) if err == sql.ErrNoRows { // We don't have a numeric ID so insert one into the database. - eventTypeNID, err = d.EventTypesTable.InsertEventTypeNID(ctx, nil, eventType) + eventTypeNID, err = d.EventTypesTable.InsertEventTypeNID(ctx, txn, eventType) if err == sql.ErrNoRows { // We raced with another insert so run the select again. - eventTypeNID, err = d.EventTypesTable.SelectEventTypeNID(ctx, nil, eventType) + eventTypeNID, err = d.EventTypesTable.SelectEventTypeNID(ctx, txn, eventType) } } return eventTypeNID, err } func (d *Database) assignStateKeyNID( - ctx context.Context, eventStateKey string, + ctx context.Context, txn *sql.Tx, eventStateKey string, ) (types.EventStateKeyNID, error) { // Check if we already have a numeric ID in the database. - eventStateKeyNID, err := d.EventStateKeysTable.SelectEventStateKeyNID(ctx, nil, eventStateKey) + eventStateKeyNID, err := d.EventStateKeysTable.SelectEventStateKeyNID(ctx, txn, eventStateKey) if err == sql.ErrNoRows { // We don't have a numeric ID so insert one into the database. - eventStateKeyNID, err = d.EventStateKeysTable.InsertEventStateKeyNID(ctx, nil, eventStateKey) + eventStateKeyNID, err = d.EventStateKeysTable.InsertEventStateKeyNID(ctx, txn, eventStateKey) if err == sql.ErrNoRows { // We raced with another insert so run the select again. - eventStateKeyNID, err = d.EventStateKeysTable.SelectEventStateKeyNID(ctx, nil, eventStateKey) + eventStateKeyNID, err = d.EventStateKeysTable.SelectEventStateKeyNID(ctx, txn, eventStateKey) } } return eventStateKeyNID, err