summary refs log tree commit diff
path: root/synapse
diff options
context:
space:
mode:
Diffstat (limited to 'synapse')
-rw-r--r--synapse/__init__.py6
-rwxr-xr-xsynapse/_scripts/synapse_port_db.py7
-rwxr-xr-xsynapse/_scripts/update_synapse_database.py5
-rw-r--r--synapse/app/_base.py4
-rw-r--r--synapse/app/admin_cmd.py5
-rw-r--r--synapse/app/generic_worker.py5
-rw-r--r--synapse/app/homeserver.py6
-rw-r--r--synapse/config/experimental.py3
-rw-r--r--synapse/config/logger.py4
-rw-r--r--synapse/federation/federation_client.py4
-rw-r--r--synapse/federation/sender/per_destination_queue.py31
-rw-r--r--synapse/federation/transport/server/federation.py4
-rw-r--r--synapse/handlers/auth.py8
-rw-r--r--synapse/handlers/device.py33
-rw-r--r--synapse/handlers/federation.py13
-rw-r--r--synapse/handlers/federation_event.py2
-rw-r--r--synapse/handlers/message.py1
-rw-r--r--synapse/metrics/__init__.py4
-rw-r--r--synapse/module_api/__init__.py2
-rw-r--r--synapse/rest/admin/__init__.py5
-rw-r--r--synapse/rest/admin/devices.py2
-rw-r--r--synapse/rest/client/devices.py4
-rw-r--r--synapse/rest/client/logout.py4
-rw-r--r--synapse/rest/client/relations.py13
-rw-r--r--synapse/state/v2.py57
-rw-r--r--synapse/storage/controllers/persist_events.py5
-rw-r--r--synapse/storage/controllers/state.py3
-rw-r--r--synapse/storage/databases/main/devices.py10
-rw-r--r--synapse/storage/databases/main/events.py2
-rw-r--r--synapse/storage/databases/main/receipts.py5
-rw-r--r--synapse/storage/databases/main/room.py2
-rw-r--r--synapse/storage/databases/main/state.py8
-rw-r--r--synapse/storage/engines/__init__.py38
-rw-r--r--synapse/storage/engines/postgres.py24
-rw-r--r--synapse/storage/prepare_database.py3
-rw-r--r--synapse/storage/state.py1
-rw-r--r--synapse/util/__init__.py6
37 files changed, 197 insertions, 142 deletions
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 1613941759..b1369aca8f 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -20,8 +20,6 @@ import json
 import os
 import sys
 
-from matrix_common.versionstring import get_distribution_version_string
-
 # Check that we're not running on an unsupported Python version.
 if sys.version_info < (3, 7):
     print("Synapse requires Python 3.7 or above.")
@@ -70,7 +68,9 @@ try:
 except ImportError:
     pass
 
-__version__ = get_distribution_version_string("matrix-synapse")
+import synapse.util
+
+__version__ = synapse.util.SYNAPSE_VERSION
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/_scripts/synapse_port_db.py b/synapse/_scripts/synapse_port_db.py
index 361b51d2fa..c753dfa7cb 100755
--- a/synapse/_scripts/synapse_port_db.py
+++ b/synapse/_scripts/synapse_port_db.py
@@ -40,7 +40,6 @@ from typing import (
 )
 
 import yaml
-from matrix_common.versionstring import get_distribution_version_string
 from typing_extensions import TypedDict
 
 from twisted.internet import defer, reactor as reactor_
@@ -84,7 +83,7 @@ from synapse.storage.databases.state.bg_updates import StateBackgroundUpdateStor
 from synapse.storage.engines import create_engine
 from synapse.storage.prepare_database import prepare_database
 from synapse.types import ISynapseReactor
-from synapse.util import Clock
+from synapse.util import SYNAPSE_VERSION, Clock
 
 # Cast safety: Twisted does some naughty magic which replaces the
 # twisted.internet.reactor module with a Reactor instance at runtime.
@@ -258,9 +257,7 @@ class MockHomeserver:
         self.clock = Clock(reactor)
         self.config = config
         self.hostname = config.server.server_name
-        self.version_string = "Synapse/" + get_distribution_version_string(
-            "matrix-synapse"
-        )
+        self.version_string = SYNAPSE_VERSION
 
     def get_clock(self) -> Clock:
         return self.clock
diff --git a/synapse/_scripts/update_synapse_database.py b/synapse/_scripts/update_synapse_database.py
index c443522c05..b4aeae6dd5 100755
--- a/synapse/_scripts/update_synapse_database.py
+++ b/synapse/_scripts/update_synapse_database.py
@@ -19,7 +19,6 @@ import sys
 from typing import cast
 
 import yaml
-from matrix_common.versionstring import get_distribution_version_string
 
 from twisted.internet import defer, reactor as reactor_
 
@@ -28,6 +27,7 @@ from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.server import HomeServer
 from synapse.storage import DataStore
 from synapse.types import ISynapseReactor
+from synapse.util import SYNAPSE_VERSION
 
 # Cast safety: Twisted does some naughty magic which replaces the
 # twisted.internet.reactor module with a Reactor instance at runtime.
@@ -43,8 +43,7 @@ class MockHomeserver(HomeServer):
             hostname=config.server.server_name,
             config=config,
             reactor=reactor,
-            version_string="Synapse/"
-            + get_distribution_version_string("matrix-synapse"),
+            version_string=f"Synapse/{SYNAPSE_VERSION}",
         )
 
 
diff --git a/synapse/app/_base.py b/synapse/app/_base.py
index a3446ac6e8..84e389a6cd 100644
--- a/synapse/app/_base.py
+++ b/synapse/app/_base.py
@@ -37,7 +37,6 @@ from typing import (
 )
 
 from cryptography.utils import CryptographyDeprecationWarning
-from matrix_common.versionstring import get_distribution_version_string
 from typing_extensions import ParamSpec
 
 import twisted
@@ -68,6 +67,7 @@ from synapse.metrics import install_gc_manager, register_threadpool
 from synapse.metrics.background_process_metrics import wrap_as_background_process
 from synapse.metrics.jemalloc import setup_jemalloc_stats
 from synapse.types import ISynapseReactor
+from synapse.util import SYNAPSE_VERSION
 from synapse.util.caches.lrucache import setup_expire_lru_cache_entries
 from synapse.util.daemonize import daemonize_process
 from synapse.util.gai_resolver import GAIResolver
@@ -540,7 +540,7 @@ def setup_sentry(hs: "HomeServer") -> None:
 
     sentry_sdk.init(
         dsn=hs.config.metrics.sentry_dsn,
-        release=get_distribution_version_string("matrix-synapse"),
+        release=SYNAPSE_VERSION,
     )
 
     # We set some default tags that give some context to this instance
diff --git a/synapse/app/admin_cmd.py b/synapse/app/admin_cmd.py
index 6fedf681f8..561621a285 100644
--- a/synapse/app/admin_cmd.py
+++ b/synapse/app/admin_cmd.py
@@ -19,8 +19,6 @@ import sys
 import tempfile
 from typing import List, Optional
 
-from matrix_common.versionstring import get_distribution_version_string
-
 from twisted.internet import defer, task
 
 import synapse
@@ -43,6 +41,7 @@ from synapse.replication.slave.storage.registration import SlavedRegistrationSto
 from synapse.server import HomeServer
 from synapse.storage.databases.main.room import RoomWorkerStore
 from synapse.types import StateMap
+from synapse.util import SYNAPSE_VERSION
 from synapse.util.logcontext import LoggingContext
 
 logger = logging.getLogger("synapse.app.admin_cmd")
@@ -220,7 +219,7 @@ def start(config_options: List[str]) -> None:
     ss = AdminCmdServer(
         config.server.server_name,
         config=config,
-        version_string="Synapse/" + get_distribution_version_string("matrix-synapse"),
+        version_string=f"Synapse/{SYNAPSE_VERSION}",
     )
 
     setup_logging(ss, config, use_worker_options=True)
diff --git a/synapse/app/generic_worker.py b/synapse/app/generic_worker.py
index 89f8998f0e..4a987fb759 100644
--- a/synapse/app/generic_worker.py
+++ b/synapse/app/generic_worker.py
@@ -16,8 +16,6 @@ import logging
 import sys
 from typing import Dict, List, Optional, Tuple
 
-from matrix_common.versionstring import get_distribution_version_string
-
 from twisted.internet import address
 from twisted.web.resource import Resource
 
@@ -121,6 +119,7 @@ from synapse.storage.databases.main.transactions import TransactionWorkerStore
 from synapse.storage.databases.main.ui_auth import UIAuthWorkerStore
 from synapse.storage.databases.main.user_directory import UserDirectoryStore
 from synapse.types import JsonDict
+from synapse.util import SYNAPSE_VERSION
 from synapse.util.httpresourcetree import create_resource_tree
 
 logger = logging.getLogger("synapse.app.generic_worker")
@@ -447,7 +446,7 @@ def start(config_options: List[str]) -> None:
     hs = GenericWorkerServer(
         config.server.server_name,
         config=config,
-        version_string="Synapse/" + get_distribution_version_string("matrix-synapse"),
+        version_string=f"Synapse/{SYNAPSE_VERSION}",
     )
 
     setup_logging(hs, config, use_worker_options=True)
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index 4c6c0658ab..745e704141 100644
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -18,8 +18,6 @@ import os
 import sys
 from typing import Dict, Iterable, List
 
-from matrix_common.versionstring import get_distribution_version_string
-
 from twisted.internet.tcp import Port
 from twisted.web.resource import EncodingResourceWrapper, Resource
 from twisted.web.server import GzipEncoderFactory
@@ -69,7 +67,7 @@ from synapse.rest.synapse.client import build_synapse_client_resource_tree
 from synapse.rest.well_known import well_known_resource
 from synapse.server import HomeServer
 from synapse.storage import DataStore
-from synapse.util.check_dependencies import check_requirements
+from synapse.util.check_dependencies import VERSION, check_requirements
 from synapse.util.httpresourcetree import create_resource_tree
 from synapse.util.module_loader import load_module
 
@@ -371,7 +369,7 @@ def setup(config_options: List[str]) -> SynapseHomeServer:
     hs = SynapseHomeServer(
         config.server.server_name,
         config=config,
-        version_string="Synapse/" + get_distribution_version_string("matrix-synapse"),
+        version_string=f"Synapse/{VERSION}",
     )
 
     synapse.config.logger.setup_logging(hs, config, use_worker_options=False)
diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py
index f2dfd49b07..0a285dba31 100644
--- a/synapse/config/experimental.py
+++ b/synapse/config/experimental.py
@@ -84,3 +84,6 @@ class ExperimentalConfig(Config):
 
         # MSC3772: A push rule for mutual relations.
         self.msc3772_enabled: bool = experimental.get("msc3772_enabled", False)
+
+        # MSC3715: dir param on /relations.
+        self.msc3715_enabled: bool = experimental.get("msc3715_enabled", False)
diff --git a/synapse/config/logger.py b/synapse/config/logger.py
index 470b8b4492..82a5b5fa12 100644
--- a/synapse/config/logger.py
+++ b/synapse/config/logger.py
@@ -22,7 +22,6 @@ from string import Template
 from typing import TYPE_CHECKING, Any, Dict, Optional
 
 import yaml
-from matrix_common.versionstring import get_distribution_version_string
 from zope.interface import implementer
 
 from twisted.logger import (
@@ -37,6 +36,7 @@ from synapse.logging.context import LoggingContextFilter
 from synapse.logging.filter import MetadataFilter
 from synapse.types import JsonDict
 
+from ..util import SYNAPSE_VERSION
 from ._base import Config, ConfigError
 
 if TYPE_CHECKING:
@@ -349,7 +349,7 @@ def setup_logging(
     logging.warning(
         "Server %s version %s",
         sys.argv[0],
-        get_distribution_version_string("matrix-synapse"),
+        SYNAPSE_VERSION,
     )
     logging.info("Server hostname: %s", config.server.server_name)
     logging.info("Instance name: %s", hs.get_instance_name())
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index ad475a913b..66e6305562 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -1642,10 +1642,6 @@ def _validate_hierarchy_event(d: JsonDict) -> None:
     if not isinstance(event_type, str):
         raise ValueError("Invalid event: 'event_type' must be a str")
 
-    room_id = d.get("room_id")
-    if not isinstance(room_id, str):
-        raise ValueError("Invalid event: 'room_id' must be a str")
-
     state_key = d.get("state_key")
     if not isinstance(state_key, str):
         raise ValueError("Invalid event: 'state_key' must be a str")
diff --git a/synapse/federation/sender/per_destination_queue.py b/synapse/federation/sender/per_destination_queue.py
index 333ca9a97f..41d8b937af 100644
--- a/synapse/federation/sender/per_destination_queue.py
+++ b/synapse/federation/sender/per_destination_queue.py
@@ -37,6 +37,7 @@ from synapse.metrics import sent_transactions_counter
 from synapse.metrics.background_process_metrics import run_as_background_process
 from synapse.types import ReadReceipt
 from synapse.util.retryutils import NotRetryingDestination, get_retry_limiter
+from synapse.visibility import filter_events_for_server
 
 if TYPE_CHECKING:
     import synapse.server
@@ -77,6 +78,7 @@ class PerDestinationQueue:
     ):
         self._server_name = hs.hostname
         self._clock = hs.get_clock()
+        self._storage_controllers = hs.get_storage_controllers()
         self._store = hs.get_datastores().main
         self._transaction_manager = transaction_manager
         self._instance_name = hs.get_instance_name()
@@ -442,6 +444,12 @@ class PerDestinationQueue:
                     "This should not happen." % event_ids
                 )
 
+            logger.info(
+                "Catching up destination %s with %d PDUs",
+                self._destination,
+                len(catchup_pdus),
+            )
+
             # We send transactions with events from one room only, as its likely
             # that the remote will have to do additional processing, which may
             # take some time. It's better to give it small amounts of work
@@ -487,19 +495,20 @@ class PerDestinationQueue:
                         ):
                             continue
 
-                        # Filter out events where the server is not in the room,
-                        # e.g. it may have left/been kicked. *Ideally* we'd pull
-                        # out the kick and send that, but it's a rare edge case
-                        # so we don't bother for now (the server that sent the
-                        # kick should send it out if its online).
-                        hosts = await self._state.get_hosts_in_room_at_events(
-                            p.room_id, [p.event_id]
-                        )
-                        if self._destination not in hosts:
-                            continue
-
                         new_pdus.append(p)
 
+                    # Filter out events where the server is not in the room,
+                    # e.g. it may have left/been kicked. *Ideally* we'd pull
+                    # out the kick and send that, but it's a rare edge case
+                    # so we don't bother for now (the server that sent the
+                    # kick should send it out if its online).
+                    new_pdus = await filter_events_for_server(
+                        self._storage_controllers,
+                        self._destination,
+                        new_pdus,
+                        redact=False,
+                    )
+
                     # If we've filtered out all the extremities, fall back to
                     # sending the original event. This should ensure that the
                     # server gets at least some of missed events (especially if
diff --git a/synapse/federation/transport/server/federation.py b/synapse/federation/transport/server/federation.py
index 7dfb890661..f7884bfbe0 100644
--- a/synapse/federation/transport/server/federation.py
+++ b/synapse/federation/transport/server/federation.py
@@ -24,7 +24,6 @@ from typing import (
     Union,
 )
 
-from matrix_common.versionstring import get_distribution_version_string
 from typing_extensions import Literal
 
 from synapse.api.constants import EduTypes
@@ -42,6 +41,7 @@ from synapse.http.servlet import (
     parse_strings_from_args,
 )
 from synapse.types import JsonDict
+from synapse.util import SYNAPSE_VERSION
 from synapse.util.ratelimitutils import FederationRateLimiter
 
 if TYPE_CHECKING:
@@ -622,7 +622,7 @@ class FederationVersionServlet(BaseFederationServlet):
             {
                 "server": {
                     "name": "Synapse",
-                    "version": get_distribution_version_string("matrix-synapse"),
+                    "version": SYNAPSE_VERSION,
                 }
             },
         )
diff --git a/synapse/handlers/auth.py b/synapse/handlers/auth.py
index fbafbbee6b..6e15028b0a 100644
--- a/synapse/handlers/auth.py
+++ b/synapse/handlers/auth.py
@@ -81,6 +81,8 @@ if TYPE_CHECKING:
 
 logger = logging.getLogger(__name__)
 
+INVALID_USERNAME_OR_PASSWORD = "Invalid username or password"
+
 
 def convert_client_dict_legacy_fields_to_identifier(
     submission: JsonDict,
@@ -1215,7 +1217,9 @@ class AuthHandler:
                     await self._failed_login_attempts_ratelimiter.can_do_action(
                         None, (medium, address)
                     )
-                raise LoginError(403, "", errcode=Codes.FORBIDDEN)
+                raise LoginError(
+                    403, msg=INVALID_USERNAME_OR_PASSWORD, errcode=Codes.FORBIDDEN
+                )
 
             identifier_dict = {"type": "m.id.user", "user": user_id}
 
@@ -1341,7 +1345,7 @@ class AuthHandler:
 
         # We raise a 403 here, but note that if we're doing user-interactive
         # login, it turns all LoginErrors into a 401 anyway.
-        raise LoginError(403, "Invalid password", errcode=Codes.FORBIDDEN)
+        raise LoginError(403, msg=INVALID_USERNAME_OR_PASSWORD, errcode=Codes.FORBIDDEN)
 
     async def check_password_provider_3pid(
         self, medium: str, address: str, password: str
diff --git a/synapse/handlers/device.py b/synapse/handlers/device.py
index a0cbeedc30..b79c551703 100644
--- a/synapse/handlers/device.py
+++ b/synapse/handlers/device.py
@@ -398,35 +398,6 @@ class DeviceHandler(DeviceWorkerHandler):
             await self.delete_devices(user_id, user_devices)
 
     @trace
-    async def delete_device(self, user_id: str, device_id: str) -> None:
-        """Delete the given device
-
-        Args:
-            user_id: The user to delete the device from.
-            device_id: The device to delete.
-        """
-
-        try:
-            await self.store.delete_device(user_id, device_id)
-        except errors.StoreError as e:
-            if e.code == 404:
-                # no match
-                set_tag("error", True)
-                log_kv(
-                    {"reason": "User doesn't have device id.", "device_id": device_id}
-                )
-            else:
-                raise
-
-        await self._auth_handler.delete_access_tokens_for_user(
-            user_id, device_id=device_id
-        )
-
-        await self.store.delete_e2e_keys_by_device(user_id=user_id, device_id=device_id)
-
-        await self.notify_device_update(user_id, [device_id])
-
-    @trace
     async def delete_all_devices_for_user(
         self, user_id: str, except_device_id: Optional[str] = None
     ) -> None:
@@ -591,7 +562,7 @@ class DeviceHandler(DeviceWorkerHandler):
             user_id, device_id, device_data
         )
         if old_device_id is not None:
-            await self.delete_device(user_id, old_device_id)
+            await self.delete_devices(user_id, [old_device_id])
         return device_id
 
     async def get_dehydrated_device(
@@ -638,7 +609,7 @@ class DeviceHandler(DeviceWorkerHandler):
         await self.store.update_device(user_id, device_id, old_device["display_name"])
         # can't call self.delete_device because that will clobber the
         # access token so call the storage layer directly
-        await self.store.delete_device(user_id, old_device_id)
+        await self.store.delete_devices(user_id, [old_device_id])
         await self.store.delete_e2e_keys_by_device(
             user_id=user_id, device_id=old_device_id
         )
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 6310f0ef27..1e5694244a 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -545,6 +545,7 @@ class FederationHandler:
             if ret.partial_state:
                 # TODO(faster_joins): roll this back if we don't manage to start the
                 #   background resync (eg process_remote_join fails)
+                #   https://github.com/matrix-org/synapse/issues/12998
                 await self.store.store_partial_state_room(room_id, ret.servers_in_room)
 
             max_stream_id = await self._federation_event_handler.process_remote_join(
@@ -1498,14 +1499,17 @@ class FederationHandler:
         # TODO(faster_joins): do we need to lock to avoid races? What happens if other
         #   worker processes kick off a resync in parallel? Perhaps we should just elect
         #   a single worker to do the resync.
+        #   https://github.com/matrix-org/synapse/issues/12994
         #
         # TODO(faster_joins): what happens if we leave the room during a resync? if we
         #   really leave, that might mean we have difficulty getting the room state over
         #   federation.
+        #   https://github.com/matrix-org/synapse/issues/12802
         #
         # TODO(faster_joins): we need some way of prioritising which homeservers in
         #   `other_destinations` to try first, otherwise we'll spend ages trying dead
         #   homeservers for large rooms.
+        #   https://github.com/matrix-org/synapse/issues/12999
 
         if initial_destination is None and len(other_destinations) == 0:
             raise ValueError(
@@ -1535,9 +1539,11 @@ class FederationHandler:
                 # all the events are updated, so we can update current state and
                 # clear the lazy-loading flag.
                 logger.info("Updating current state for %s", room_id)
+                # TODO(faster_joins): support workers
+                #   https://github.com/matrix-org/synapse/issues/12994
                 assert (
                     self._storage_controllers.persistence is not None
-                ), "TODO(faster_joins): support for workers"
+                ), "worker-mode deployments not currently supported here"
                 await self._storage_controllers.persistence.update_current_state(
                     room_id
                 )
@@ -1551,6 +1557,8 @@ class FederationHandler:
                     )
 
                     # TODO(faster_joins) update room stats and user directory?
+                    #   https://github.com/matrix-org/synapse/issues/12814
+                    #   https://github.com/matrix-org/synapse/issues/12815
                     return
 
                 # we raced against more events arriving with partial state. Go round
@@ -1558,6 +1566,8 @@ class FederationHandler:
                 # TODO(faster_joins): there is still a race here, whereby incoming events which raced
                 #   with us will fail to be persisted after the call to `clear_partial_state_room` due to
                 #   having partial state.
+                #   https://github.com/matrix-org/synapse/issues/12988
+                #
                 continue
 
             events = await self.store.get_events_as_list(
@@ -1580,6 +1590,7 @@ class FederationHandler:
                             #   indefinitely is also not the right thing to do if we can
                             #   reach all homeservers and they all claim they don't have
                             #   the state we want.
+                            #   https://github.com/matrix-org/synapse/issues/13000
                             logger.error(
                                 "Failed to get state for %s at %s from %s because %s, "
                                 "giving up!",
diff --git a/synapse/handlers/federation_event.py b/synapse/handlers/federation_event.py
index 9488fef297..6c9e6a00b5 100644
--- a/synapse/handlers/federation_event.py
+++ b/synapse/handlers/federation_event.py
@@ -532,6 +532,7 @@ class FederationEventHandler:
                 #
                 # TODO(faster_joins): we probably need to be more intelligent, and
                 #    exclude partial-state prev_events from consideration
+                #    https://github.com/matrix-org/synapse/issues/13001
                 logger.warning(
                     "%s still has partial state: can't de-partial-state it yet",
                     event.event_id,
@@ -777,6 +778,7 @@ class FederationEventHandler:
             state_ids = await self._resolve_state_at_missing_prevs(origin, event)
             # TODO(faster_joins): make sure that _resolve_state_at_missing_prevs does
             #   not return partial state
+            #   https://github.com/matrix-org/synapse/issues/13002
 
             await self._process_received_pdu(
                 origin, event, state_ids=state_ids, backfilled=backfilled
diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index c8bbcfd8c2..9b17939163 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -1102,6 +1102,7 @@ class EventCreationHandler:
             #
             # TODO(faster_joins): figure out how this works, and make sure that the
             #   old state is complete.
+            #   https://github.com/matrix-org/synapse/issues/13003
             metadata = await self.store.get_metadata_for_events(state_event_ids)
 
             state_map_for_event: MutableStateMap[str] = {}
diff --git a/synapse/metrics/__init__.py b/synapse/metrics/__init__.py
index fffd83546c..496fce2ecc 100644
--- a/synapse/metrics/__init__.py
+++ b/synapse/metrics/__init__.py
@@ -35,7 +35,6 @@ from typing import (
 )
 
 import attr
-from matrix_common.versionstring import get_distribution_version_string
 from prometheus_client import CollectorRegistry, Counter, Gauge, Histogram, Metric
 from prometheus_client.core import (
     REGISTRY,
@@ -54,6 +53,7 @@ from synapse.metrics._exposition import (
 )
 from synapse.metrics._gc import MIN_TIME_BETWEEN_GCS, install_gc_manager
 from synapse.metrics._types import Collector
+from synapse.util import SYNAPSE_VERSION
 
 logger = logging.getLogger(__name__)
 
@@ -419,7 +419,7 @@ build_info = Gauge(
 )
 build_info.labels(
     " ".join([platform.python_implementation(), platform.python_version()]),
-    get_distribution_version_string("matrix-synapse"),
+    SYNAPSE_VERSION,
     " ".join([platform.system(), platform.release()]),
 ).set(1)
 
diff --git a/synapse/module_api/__init__.py b/synapse/module_api/__init__.py
index a8ad575fcd..30b2aeffdd 100644
--- a/synapse/module_api/__init__.py
+++ b/synapse/module_api/__init__.py
@@ -799,7 +799,7 @@ class ModuleApi:
         if device_id:
             # delete the device, which will also delete its access tokens
             yield defer.ensureDeferred(
-                self._hs.get_device_handler().delete_device(user_id, device_id)
+                self._hs.get_device_handler().delete_devices(user_id, [device_id])
             )
         else:
             # no associated device. Just delete the access token.
diff --git a/synapse/rest/admin/__init__.py b/synapse/rest/admin/__init__.py
index 1aa08f8d95..fa3266720b 100644
--- a/synapse/rest/admin/__init__.py
+++ b/synapse/rest/admin/__init__.py
@@ -20,8 +20,6 @@ import platform
 from http import HTTPStatus
 from typing import TYPE_CHECKING, Optional, Tuple
 
-from matrix_common.versionstring import get_distribution_version_string
-
 from synapse.api.errors import Codes, NotFoundError, SynapseError
 from synapse.http.server import HttpServer, JsonResource
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
@@ -88,6 +86,7 @@ from synapse.rest.admin.users import (
     WhoisRestServlet,
 )
 from synapse.types import JsonDict, RoomStreamToken
+from synapse.util import SYNAPSE_VERSION
 
 if TYPE_CHECKING:
     from synapse.server import HomeServer
@@ -100,7 +99,7 @@ class VersionServlet(RestServlet):
 
     def __init__(self, hs: "HomeServer"):
         self.res = {
-            "server_version": get_distribution_version_string("matrix-synapse"),
+            "server_version": SYNAPSE_VERSION,
             "python_version": platform.python_version(),
         }
 
diff --git a/synapse/rest/admin/devices.py b/synapse/rest/admin/devices.py
index cef46ba0dd..d934880102 100644
--- a/synapse/rest/admin/devices.py
+++ b/synapse/rest/admin/devices.py
@@ -80,7 +80,7 @@ class DeviceRestServlet(RestServlet):
         if u is None:
             raise NotFoundError("Unknown user")
 
-        await self.device_handler.delete_device(target_user.to_string(), device_id)
+        await self.device_handler.delete_devices(target_user.to_string(), [device_id])
         return HTTPStatus.OK, {}
 
     async def on_PUT(
diff --git a/synapse/rest/client/devices.py b/synapse/rest/client/devices.py
index ad6fd6492b..6fab102437 100644
--- a/synapse/rest/client/devices.py
+++ b/synapse/rest/client/devices.py
@@ -147,7 +147,9 @@ class DeviceRestServlet(RestServlet):
             can_skip_ui_auth=True,
         )
 
-        await self.device_handler.delete_device(requester.user.to_string(), device_id)
+        await self.device_handler.delete_devices(
+            requester.user.to_string(), [device_id]
+        )
         return 200, {}
 
     async def on_PUT(
diff --git a/synapse/rest/client/logout.py b/synapse/rest/client/logout.py
index 193a6951b9..23dfa4518f 100644
--- a/synapse/rest/client/logout.py
+++ b/synapse/rest/client/logout.py
@@ -45,8 +45,8 @@ class LogoutRestServlet(RestServlet):
             access_token = self.auth.get_access_token_from_request(request)
             await self._auth_handler.delete_access_token(access_token)
         else:
-            await self._device_handler.delete_device(
-                requester.user.to_string(), requester.device_id
+            await self._device_handler.delete_devices(
+                requester.user.to_string(), [requester.device_id]
             )
 
         return 200, {}
diff --git a/synapse/rest/client/relations.py b/synapse/rest/client/relations.py
index 3cae6d2b55..ce97080013 100644
--- a/synapse/rest/client/relations.py
+++ b/synapse/rest/client/relations.py
@@ -43,6 +43,7 @@ class RelationPaginationServlet(RestServlet):
         self.auth = hs.get_auth()
         self.store = hs.get_datastores().main
         self._relations_handler = hs.get_relations_handler()
+        self._msc3715_enabled = hs.config.experimental.msc3715_enabled
 
     async def on_GET(
         self,
@@ -55,9 +56,15 @@ class RelationPaginationServlet(RestServlet):
         requester = await self.auth.get_user_by_req(request, allow_guest=True)
 
         limit = parse_integer(request, "limit", default=5)
-        direction = parse_string(
-            request, "org.matrix.msc3715.dir", default="b", allowed_values=["f", "b"]
-        )
+        if self._msc3715_enabled:
+            direction = parse_string(
+                request,
+                "org.matrix.msc3715.dir",
+                default="b",
+                allowed_values=["f", "b"],
+            )
+        else:
+            direction = "b"
         from_token_str = parse_string(request, "from")
         to_token_str = parse_string(request, "to")
 
diff --git a/synapse/state/v2.py b/synapse/state/v2.py
index 041ccac59e..6a16f38a15 100644
--- a/synapse/state/v2.py
+++ b/synapse/state/v2.py
@@ -17,12 +17,14 @@ import itertools
 import logging
 from typing import (
     Any,
+    Awaitable,
     Callable,
     Collection,
     Dict,
     Generator,
     Iterable,
     List,
+    Mapping,
     Optional,
     Sequence,
     Set,
@@ -30,33 +32,58 @@ from typing import (
     overload,
 )
 
-from typing_extensions import Literal
+from typing_extensions import Literal, Protocol
 
-import synapse.state
 from synapse import event_auth
 from synapse.api.constants import EventTypes
 from synapse.api.errors import AuthError
 from synapse.api.room_versions import RoomVersion
 from synapse.events import EventBase
 from synapse.types import MutableStateMap, StateMap
-from synapse.util import Clock
 
 logger = logging.getLogger(__name__)
 
 
+class Clock(Protocol):
+    # This is usually synapse.util.Clock, but it's replaced with a FakeClock in tests.
+    # We only ever sleep(0) though, so that other async functions can make forward
+    # progress without waiting for stateres to complete.
+    def sleep(self, duration_ms: float) -> Awaitable[None]:
+        ...
+
+
+class StateResolutionStore(Protocol):
+    # This is usually synapse.state.StateResolutionStore, but it's replaced with a
+    # TestStateResolutionStore in tests.
+    def get_events(
+        self, event_ids: Collection[str], allow_rejected: bool = False
+    ) -> Awaitable[Dict[str, EventBase]]:
+        ...
+
+    def get_auth_chain_difference(
+        self, room_id: str, state_sets: List[Set[str]]
+    ) -> Awaitable[Set[str]]:
+        ...
+
+
 # We want to await to the reactor occasionally during state res when dealing
 # with large data sets, so that we don't exhaust the reactor. This is done by
 # awaiting to reactor during loops every N iterations.
 _AWAIT_AFTER_ITERATIONS = 100
 
 
+__all__ = [
+    "resolve_events_with_store",
+]
+
+
 async def resolve_events_with_store(
     clock: Clock,
     room_id: str,
     room_version: RoomVersion,
     state_sets: Sequence[StateMap[str]],
     event_map: Optional[Dict[str, EventBase]],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
 ) -> StateMap[str]:
     """Resolves the state using the v2 state resolution algorithm
 
@@ -194,7 +221,7 @@ async def _get_power_level_for_sender(
     room_id: str,
     event_id: str,
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
 ) -> int:
     """Return the power level of the sender of the given event according to
     their auth events.
@@ -243,9 +270,9 @@ async def _get_power_level_for_sender(
 
 async def _get_auth_chain_difference(
     room_id: str,
-    state_sets: Sequence[StateMap[str]],
+    state_sets: Sequence[Mapping[Any, str]],
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
 ) -> Set[str]:
     """Compare the auth chains of each state set and return the set of events
     that only appear in some but not all of the auth chains.
@@ -406,7 +433,7 @@ async def _add_event_and_auth_chain_to_graph(
     room_id: str,
     event_id: str,
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
     auth_diff: Set[str],
 ) -> None:
     """Helper function for _reverse_topological_power_sort that add the event
@@ -440,7 +467,7 @@ async def _reverse_topological_power_sort(
     room_id: str,
     event_ids: Iterable[str],
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
     auth_diff: Set[str],
 ) -> List[str]:
     """Returns a list of the event_ids sorted by reverse topological ordering,
@@ -501,7 +528,7 @@ async def _iterative_auth_checks(
     event_ids: List[str],
     base_state: StateMap[str],
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
 ) -> MutableStateMap[str]:
     """Sequentially apply auth checks to each event in given list, updating the
     state as it goes along.
@@ -569,7 +596,7 @@ async def _mainline_sort(
     event_ids: List[str],
     resolved_power_event_id: Optional[str],
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
 ) -> List[str]:
     """Returns a sorted list of event_ids sorted by mainline ordering based on
     the given event resolved_power_event_id
@@ -638,7 +665,7 @@ async def _get_mainline_depth_for_event(
     event: EventBase,
     mainline_map: Dict[str, int],
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
 ) -> int:
     """Get the mainline depths for the given event based on the mainline map
 
@@ -682,7 +709,7 @@ async def _get_event(
     room_id: str,
     event_id: str,
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
     allow_none: Literal[False] = False,
 ) -> EventBase:
     ...
@@ -693,7 +720,7 @@ async def _get_event(
     room_id: str,
     event_id: str,
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
     allow_none: Literal[True],
 ) -> Optional[EventBase]:
     ...
@@ -703,7 +730,7 @@ async def _get_event(
     room_id: str,
     event_id: str,
     event_map: Dict[str, EventBase],
-    state_res_store: "synapse.state.StateResolutionStore",
+    state_res_store: StateResolutionStore,
     allow_none: bool = False,
 ) -> Optional[EventBase]:
     """Helper function to look up event in event_map, falling back to looking
diff --git a/synapse/storage/controllers/persist_events.py b/synapse/storage/controllers/persist_events.py
index 4caaa81808..4bcb99d06e 100644
--- a/synapse/storage/controllers/persist_events.py
+++ b/synapse/storage/controllers/persist_events.py
@@ -388,10 +388,13 @@ class EventsPersistenceStorageController:
 
         # TODO(faster_joins): get a real stream ordering, to make this work correctly
         #    across workers.
+        #    https://github.com/matrix-org/synapse/issues/12994
         #
         # TODO(faster_joins): this can race against event persistence, in which case we
         #    will end up with incorrect state. Perhaps we should make this a job we
-        #    farm out to the event persister, somehow.
+        #    farm out to the event persister thread, somehow.
+        #    https://github.com/matrix-org/synapse/issues/13007
+        #
         stream_id = self.main_store.get_room_max_stream_ordering()
         await self.persist_events_store.update_current_state(room_id, delta, stream_id)
 
diff --git a/synapse/storage/controllers/state.py b/synapse/storage/controllers/state.py
index 3b4cdb67eb..d3a44bc876 100644
--- a/synapse/storage/controllers/state.py
+++ b/synapse/storage/controllers/state.py
@@ -452,6 +452,9 @@ class StateStorageController:
                  up to date.
         """
         # FIXME(faster_joins): what do we do here?
+        #   https://github.com/matrix-org/synapse/issues/12814
+        #   https://github.com/matrix-org/synapse/issues/12815
+        #   https://github.com/matrix-org/synapse/issues/13008
 
         return await self.stores.main.get_partial_current_state_deltas(
             prev_stream_id, max_stream_id
diff --git a/synapse/storage/databases/main/devices.py b/synapse/storage/databases/main/devices.py
index d900064c07..71e7863dd8 100644
--- a/synapse/storage/databases/main/devices.py
+++ b/synapse/storage/databases/main/devices.py
@@ -1433,16 +1433,6 @@ class DeviceStore(DeviceWorkerStore, DeviceBackgroundUpdateStore):
             )
             raise StoreError(500, "Problem storing device.")
 
-    async def delete_device(self, user_id: str, device_id: str) -> None:
-        """Delete a device and its device_inbox.
-
-        Args:
-            user_id: The ID of the user which owns the device
-            device_id: The ID of the device to delete
-        """
-
-        await self.delete_devices(user_id, [device_id])
-
     async def delete_devices(self, user_id: str, device_ids: List[str]) -> None:
         """Deletes several devices.
 
diff --git a/synapse/storage/databases/main/events.py b/synapse/storage/databases/main/events.py
index 17e35cf63e..a8773374be 100644
--- a/synapse/storage/databases/main/events.py
+++ b/synapse/storage/databases/main/events.py
@@ -46,7 +46,7 @@ from synapse.storage.database import (
 )
 from synapse.storage.databases.main.events_worker import EventCacheEntry
 from synapse.storage.databases.main.search import SearchEntry
-from synapse.storage.engines.postgres import PostgresEngine
+from synapse.storage.engines import PostgresEngine
 from synapse.storage.util.id_generators import AbstractStreamIdGenerator
 from synapse.storage.util.sequence import SequenceGenerator
 from synapse.types import JsonDict, StateMap, get_domain_from_id
diff --git a/synapse/storage/databases/main/receipts.py b/synapse/storage/databases/main/receipts.py
index 21e954ccc1..b6106affa6 100644
--- a/synapse/storage/databases/main/receipts.py
+++ b/synapse/storage/databases/main/receipts.py
@@ -36,6 +36,7 @@ from synapse.storage.database import (
     LoggingTransaction,
 )
 from synapse.storage.engines import PostgresEngine
+from synapse.storage.engines._base import IsolationLevel
 from synapse.storage.util.id_generators import (
     AbstractStreamIdTracker,
     MultiWriterIdGenerator,
@@ -764,6 +765,10 @@ class ReceiptsWorkerStore(SQLBaseStore):
                 linearized_event_id,
                 data,
                 stream_id=stream_id,
+                # Read committed is actually beneficial here because we check for a receipt with
+                # greater stream order, and checking the very latest data at select time is better
+                # than the data at transaction start time.
+                isolation_level=IsolationLevel.READ_COMMITTED,
             )
 
         # If the receipt was older than the currently persisted one, nothing to do.
diff --git a/synapse/storage/databases/main/room.py b/synapse/storage/databases/main/room.py
index 68d4fc2e64..5760d3428e 100644
--- a/synapse/storage/databases/main/room.py
+++ b/synapse/storage/databases/main/room.py
@@ -1112,6 +1112,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
         # this can race with incoming events, so we watch out for FK errors.
         # TODO(faster_joins): this still doesn't completely fix the race, since the persist process
         #   is not atomic. I fear we need an application-level lock.
+        #   https://github.com/matrix-org/synapse/issues/12988
         try:
             await self.db_pool.runInteraction(
                 "clear_partial_state_room", self._clear_partial_state_room_txn, room_id
@@ -1119,6 +1120,7 @@ class RoomWorkerStore(CacheInvalidationWorkerStore):
             return True
         except self.db_pool.engine.module.DatabaseError as e:
             # TODO(faster_joins): how do we distinguish between FK errors and other errors?
+            #   https://github.com/matrix-org/synapse/issues/12988
             logger.warning(
                 "Exception while clearing lazy partial-state-room %s, retrying: %s",
                 room_id,
diff --git a/synapse/storage/databases/main/state.py b/synapse/storage/databases/main/state.py
index bdd00273cd..9674c4a757 100644
--- a/synapse/storage/databases/main/state.py
+++ b/synapse/storage/databases/main/state.py
@@ -127,13 +127,8 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
             NotFoundError: if the room is unknown
         """
 
-        # First we try looking up room version from the database, but for old
-        # rooms we might not have added the room version to it yet so we fall
-        # back to previous behaviour and look in current state events.
-        #
         # We really should have an entry in the rooms table for every room we
-        # care about, but let's be a bit paranoid (at least while the background
-        # update is happening) to avoid breaking existing rooms.
+        # care about, but let's be a bit paranoid.
         room_version = self.db_pool.simple_select_one_onecol_txn(
             txn,
             table="rooms",
@@ -440,6 +435,7 @@ class StateGroupWorkerStore(EventsWorkerStore, SQLBaseStore):
         )
 
         # TODO(faster_joins): need to do something about workers here
+        #   https://github.com/matrix-org/synapse/issues/12994
         txn.call_after(self.is_partial_state_event.invalidate, (event.event_id,))
         txn.call_after(
             self._get_state_group_for_event.prefill,
diff --git a/synapse/storage/engines/__init__.py b/synapse/storage/engines/__init__.py
index f51b3d228e..a182e8a098 100644
--- a/synapse/storage/engines/__init__.py
+++ b/synapse/storage/engines/__init__.py
@@ -11,11 +11,35 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-from typing import Any, Mapping
+from typing import Any, Mapping, NoReturn
 
 from ._base import BaseDatabaseEngine, IncorrectDatabaseSetup
-from .postgres import PostgresEngine
-from .sqlite import Sqlite3Engine
+
+# The classes `PostgresEngine` and `Sqlite3Engine` must always be importable, because
+# we use `isinstance(engine, PostgresEngine)` to write different queries for postgres
+# and sqlite. But the database driver modules are both optional: they may not be
+# installed. To account for this, create dummy classes on import failure so we can
+# still run `isinstance()` checks.
+try:
+    from .postgres import PostgresEngine
+except ImportError:
+
+    class PostgresEngine(BaseDatabaseEngine):  # type: ignore[no-redef]
+        def __new__(cls, *args: object, **kwargs: object) -> NoReturn:  # type: ignore[misc]
+            raise RuntimeError(
+                f"Cannot create {cls.__name__} -- psycopg2 module is not installed"
+            )
+
+
+try:
+    from .sqlite import Sqlite3Engine
+except ImportError:
+
+    class Sqlite3Engine(BaseDatabaseEngine):  # type: ignore[no-redef]
+        def __new__(cls, *args: object, **kwargs: object) -> NoReturn:  # type: ignore[misc]
+            raise RuntimeError(
+                f"Cannot create {cls.__name__} -- sqlite3 module is not installed"
+            )
 
 
 def create_engine(database_config: Mapping[str, Any]) -> BaseDatabaseEngine:
@@ -30,4 +54,10 @@ def create_engine(database_config: Mapping[str, Any]) -> BaseDatabaseEngine:
     raise RuntimeError("Unsupported database engine '%s'" % (name,))
 
 
-__all__ = ["create_engine", "BaseDatabaseEngine", "IncorrectDatabaseSetup"]
+__all__ = [
+    "create_engine",
+    "BaseDatabaseEngine",
+    "PostgresEngine",
+    "Sqlite3Engine",
+    "IncorrectDatabaseSetup",
+]
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
index 391f8ed24a..517f9d5f98 100644
--- a/synapse/storage/engines/postgres.py
+++ b/synapse/storage/engines/postgres.py
@@ -15,6 +15,8 @@
 import logging
 from typing import TYPE_CHECKING, Any, Mapping, NoReturn, Optional, Tuple, cast
 
+import psycopg2.extensions
+
 from synapse.storage.engines._base import (
     BaseDatabaseEngine,
     IncorrectDatabaseSetup,
@@ -23,18 +25,14 @@ from synapse.storage.engines._base import (
 from synapse.storage.types import Cursor
 
 if TYPE_CHECKING:
-    import psycopg2  # noqa: F401
-
     from synapse.storage.database import LoggingDatabaseConnection
 
 
 logger = logging.getLogger(__name__)
 
 
-class PostgresEngine(BaseDatabaseEngine["psycopg2.connection"]):
+class PostgresEngine(BaseDatabaseEngine[psycopg2.extensions.connection]):
     def __init__(self, database_config: Mapping[str, Any]):
-        import psycopg2.extensions
-
         super().__init__(psycopg2, database_config)
         psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
 
@@ -69,7 +67,9 @@ class PostgresEngine(BaseDatabaseEngine["psycopg2.connection"]):
         return collation, ctype
 
     def check_database(
-        self, db_conn: "psycopg2.connection", allow_outdated_version: bool = False
+        self,
+        db_conn: psycopg2.extensions.connection,
+        allow_outdated_version: bool = False,
     ) -> None:
         # Get the version of PostgreSQL that we're using. As per the psycopg2
         # docs: The number is formed by converting the major, minor, and
@@ -176,8 +176,6 @@ class PostgresEngine(BaseDatabaseEngine["psycopg2.connection"]):
         return True
 
     def is_deadlock(self, error: Exception) -> bool:
-        import psycopg2.extensions
-
         if isinstance(error, psycopg2.DatabaseError):
             # https://www.postgresql.org/docs/current/static/errcodes-appendix.html
             # "40001" serialization_failure
@@ -185,7 +183,7 @@ class PostgresEngine(BaseDatabaseEngine["psycopg2.connection"]):
             return error.pgcode in ["40001", "40P01"]
         return False
 
-    def is_connection_closed(self, conn: "psycopg2.connection") -> bool:
+    def is_connection_closed(self, conn: psycopg2.extensions.connection) -> bool:
         return bool(conn.closed)
 
     def lock_table(self, txn: Cursor, table: str) -> None:
@@ -205,18 +203,16 @@ class PostgresEngine(BaseDatabaseEngine["psycopg2.connection"]):
         else:
             return "%i.%i.%i" % (numver / 10000, (numver % 10000) / 100, numver % 100)
 
-    def in_transaction(self, conn: "psycopg2.connection") -> bool:
-        import psycopg2.extensions
-
+    def in_transaction(self, conn: psycopg2.extensions.connection) -> bool:
         return conn.status != psycopg2.extensions.STATUS_READY
 
     def attempt_to_set_autocommit(
-        self, conn: "psycopg2.connection", autocommit: bool
+        self, conn: psycopg2.extensions.connection, autocommit: bool
     ) -> None:
         return conn.set_session(autocommit=autocommit)
 
     def attempt_to_set_isolation_level(
-        self, conn: "psycopg2.connection", isolation_level: Optional[int]
+        self, conn: psycopg2.extensions.connection, isolation_level: Optional[int]
     ) -> None:
         if isolation_level is None:
             isolation_level = self.default_isolation_level
diff --git a/synapse/storage/prepare_database.py b/synapse/storage/prepare_database.py
index c33df42084..09a2b58f4c 100644
--- a/synapse/storage/prepare_database.py
+++ b/synapse/storage/prepare_database.py
@@ -23,8 +23,7 @@ from typing_extensions import Counter as CounterType
 
 from synapse.config.homeserver import HomeServerConfig
 from synapse.storage.database import LoggingDatabaseConnection
-from synapse.storage.engines import BaseDatabaseEngine
-from synapse.storage.engines.postgres import PostgresEngine
+from synapse.storage.engines import BaseDatabaseEngine, PostgresEngine
 from synapse.storage.schema import SCHEMA_COMPAT_VERSION, SCHEMA_VERSION
 from synapse.storage.types import Cursor
 
diff --git a/synapse/storage/state.py b/synapse/storage/state.py
index 96aaffb53c..af3bab2c15 100644
--- a/synapse/storage/state.py
+++ b/synapse/storage/state.py
@@ -546,6 +546,7 @@ class StateFilter:
         #  the sender of a piece of state wasn't actually in the room, then clearly that
         #  state shouldn't have been returned.
         #  We should at least add some tests around this to see what happens.
+        #  https://github.com/matrix-org/synapse/issues/13006
 
         # if we haven't requested membership events, then it depends on the value of
         # 'include_others'
diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index d8046b7553..6323d452e7 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -19,6 +19,7 @@ from typing import Any, Callable, Dict, Generator, Optional
 
 import attr
 from frozendict import frozendict
+from matrix_common.versionstring import get_distribution_version_string
 
 from twisted.internet import defer, task
 from twisted.internet.defer import Deferred
@@ -183,3 +184,8 @@ def log_failure(
     if not consumeErrors:
         return failure
     return None
+
+
+# Version string with git info. Computed here once so that we don't invoke git multiple
+# times.
+SYNAPSE_VERSION = get_distribution_version_string("matrix-synapse", __file__)