From f3ceaf432365bce77cff71116fb6c7d38e61c9ab Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Fri, 11 Oct 2019 11:22:36 +0100
Subject: [PATCH 1/2] Trace non-JSON APIs, /media, /key etc

---
 synapse/http/server.py         |  2 +-
 synapse/logging/opentracing.py | 14 ++++++++++----
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/synapse/http/server.py b/synapse/http/server.py
index cb9158fe1be2..2ccb210fd651 100644
--- a/synapse/http/server.py
+++ b/synapse/http/server.py
@@ -388,7 +388,7 @@ def render(self, request):
         if not callback:
             return super().render(request)
 
-        resp = callback(request)
+        resp = trace_servlet(self.__class__.__name__)(callback)(request)
 
         # If it's a coroutine, turn it into a Deferred
         if isinstance(resp, types.CoroutineType):
diff --git a/synapse/logging/opentracing.py b/synapse/logging/opentracing.py
index cd1ff6a51883..0638cec429d0 100644
--- a/synapse/logging/opentracing.py
+++ b/synapse/logging/opentracing.py
@@ -169,6 +169,7 @@ def set_fates(clotho, lachesis, atropos, father="Zues", mother="Themis"):
 import inspect
 import logging
 import re
+import types
 from functools import wraps
 from typing import Dict
 
@@ -778,8 +779,7 @@ def _trace_servlet_inner_1(func):
             return func
 
         @wraps(func)
-        @defer.inlineCallbacks
-        def _trace_servlet_inner(request, *args, **kwargs):
+        async def _trace_servlet_inner(request, *args, **kwargs):
             request_tags = {
                 "request_id": request.get_request_id(),
                 tags.SPAN_KIND: tags.SPAN_KIND_RPC_SERVER,
@@ -796,8 +796,14 @@ def _trace_servlet_inner(request, *args, **kwargs):
                 scope = start_active_span(servlet_name, tags=request_tags)
 
             with scope:
-                result = yield defer.maybeDeferred(func, request, *args, **kwargs)
-                return result
+                result = func(request, *args, **kwargs)
+
+                if not isinstance(result, (types.CoroutineType, defer.Deferred)):
+                    # Some servlets aren't async and just return results
+                    # directly, so we handle that here.
+                    return result
+
+                return await result
 
         return _trace_servlet_inner
 

From de3a1764266536fdc4bf87b01ed873632213eb12 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Fri, 11 Oct 2019 11:24:08 +0100
Subject: [PATCH 2/2] Newsfile

---
 changelog.d/6195.bugfix | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/6195.bugfix

diff --git a/changelog.d/6195.bugfix b/changelog.d/6195.bugfix
new file mode 100644
index 000000000000..d22935dbcd38
--- /dev/null
+++ b/changelog.d/6195.bugfix
@@ -0,0 +1 @@
+Fix tracing of non-JSON APIs, /media, /key etc.