PG: start flush on primary only after we process the master log

Once we start serving reads, stray objects must have already
been removed.  Therefore, we have to flush all operations
up to the transaction writing out the authoritative log.
On replicas, we flush in Stray() if we will not eventually
be activated and in ReplicaActive if we are in the acting
set.  This way a replica won't serve a replica read until
the store is consistent.

Signed-off-by: Samuel Just <sam.just@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>

diff --git a/src/osd/PG.cc b/src/osd/PG.cc
index 0663b86665dcc01b45083ad0c2884b00a8113744..bf522c8d9e157f47e6a054f63974d053e3b2782e 100644 (file)
--- a/src/osd/PG.cc
+++ b/src/osd/PG.cc
@@ -5163,11 +5163,6 @@ PG::RecoveryState::Started::Started(my_context ctx)
 {
   state_name = "Started";
   context< RecoveryMachine >().log_enter(state_name);
-  PG *pg = context< RecoveryMachine >().pg;
-  pg->start_flush(
-    context< RecoveryMachine >().get_cur_transaction(),
-    context< RecoveryMachine >().get_on_applied_context_list(),
-    context< RecoveryMachine >().get_on_safe_context_list());
 }
 
 boost::statechart::result
@@ -6131,6 +6126,12 @@ PG::RecoveryState::ReplicaActive::ReplicaActive(my_context ctx)
   state_name = "Started/ReplicaActive";
 
   context< RecoveryMachine >().log_enter(state_name);
+
+  PG *pg = context< RecoveryMachine >().pg;
+  pg->start_flush(
+    context< RecoveryMachine >().get_cur_transaction(),
+    context< RecoveryMachine >().get_on_applied_context_list(),
+    context< RecoveryMachine >().get_on_safe_context_list());
 }
 
 
@@ -6219,6 +6220,11 @@ PG::RecoveryState::Stray::Stray(my_context ctx)
   assert(!pg->is_active());
   assert(!pg->is_peering());
   assert(!pg->is_primary());
+  if (!pg->is_replica()) // stray, need to flush for pulls
+    pg->start_flush(
+      context< RecoveryMachine >().get_cur_transaction(),
+      context< RecoveryMachine >().get_on_applied_context_list(),
+      context< RecoveryMachine >().get_on_safe_context_list());
 }
 
 boost::statechart::result PG::RecoveryState::Stray::react(const MLogRec& logevt)
@@ -6565,6 +6571,10 @@ boost::statechart::result PG::RecoveryState::GetLog::react(const GotLog&)
                        msg->info, msg->log, msg->missing, 
                        newest_update_osd);
   }
+  pg->start_flush(
+    context< RecoveryMachine >().get_cur_transaction(),
+    context< RecoveryMachine >().get_on_applied_context_list(),
+    context< RecoveryMachine >().get_on_safe_context_list());
   return transit< GetMissing >();
 }