From: Yehuda Sadeh <yehuda@redhat.com>
Date: Thu, 19 Oct 2017 21:04:03 +0000 (-0700)
Subject: rgw: don't schedule a cr if already scheduled
X-Git-Tag: v13.1.0~270^2~73
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=2760375f874e856fb1f6898e858af8a094596541;p=ceph.git

rgw: don't schedule a cr if already scheduled

This can be triggered when multiple IOs return for the same cr. We
don't want to allow it to be scheduled multiple times, as this
might wake up blocking IOs that shouldn't be woken up. If we try to
block on an IO that we already complete, we won't block anyway.

Signed-off-by: Yehuda Sadeh <yehuda@redhat.com>
---

diff --git a/src/rgw/rgw_coroutine.cc b/src/rgw/rgw_coroutine.cc
index f4e1e0ab1dd07..852fee41f3835 100644
--- a/src/rgw/rgw_coroutine.cc
+++ b/src/rgw/rgw_coroutine.cc
@@ -513,8 +513,10 @@ void RGWCoroutinesManager::handle_unblocked_stack(set<RGWCoroutinesStack *>& con
   }
   stack->set_interval_wait(false);
   if (!stack->is_done()) {
-    scheduled_stacks.push_back(stack);
-    stack->set_is_scheduled(true);
+    if (!stack->is_scheduled) {
+      scheduled_stacks.push_back(stack);
+      stack->set_is_scheduled(true);
+    }
   } else {
     context_stacks.erase(stack);
     stack->put();
@@ -530,8 +532,10 @@ void RGWCoroutinesManager::schedule(RGWCoroutinesEnv *env, RGWCoroutinesStack *s
 void RGWCoroutinesManager::_schedule(RGWCoroutinesEnv *env, RGWCoroutinesStack *stack)
 {
   assert(lock.is_wlocked());
-  env->scheduled_stacks->push_back(stack);
-  stack->set_is_scheduled(true);
+  if (!stack->is_scheduled) {
+    env->scheduled_stacks->push_back(stack);
+    stack->set_is_scheduled(true);
+  }
   set<RGWCoroutinesStack *>& context_stacks = run_contexts[env->run_context];
   context_stacks.insert(stack);
 }
@@ -573,6 +577,8 @@ int RGWCoroutinesManager::run(list<RGWCoroutinesStack *>& stacks)
 
   for (list<RGWCoroutinesStack *>::iterator iter = scheduled_stacks.begin(); iter != scheduled_stacks.end() && !going_down;) {
     RGWCoroutinesStack *stack = *iter;
+    ++iter;
+    scheduled_stacks.pop_front();
 
     if (context_stacks.find(stack) == context_stacks.end()) {
       /* stack was probably schedule more than once due to IO, but was since complete */
@@ -662,10 +668,6 @@ int RGWCoroutinesManager::run(list<RGWCoroutinesStack *>& stacks)
     }
 
 next:
-    ++iter;
-    scheduled_stacks.pop_front();
-
-
     while (scheduled_stacks.empty() && blocked_count > 0) {
       lock.unlock();
       ret = completion_mgr->get_next(&io);