osd: populate obc watchers even when degraded

Bug #3142 appears to be caused by the following sequence:

 - object X missing on primary and replica
 - [assert-ver,watch], notify, unwatch requests come in, get deferred
 - object is recovered on primary, !missing, create_object_context
   - populate_obc_watchers() does nothing, since still degraded
 - notify happens now (odd but ok?)
 - replica recovered, !degraded
 - watch skips bc of bad assert
 - unwatch trips up on an assert because populate_obc_watchers never
   ran

Fix this by populating the obc watcher when !missing, not when
!degraded.  This conditional dates back to Sam's original watch/notify
cleanup in October 2011.

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

diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index ceafaadd270d450263ad746b2db4d92876070e26..cdc055987cbcd3b5dc2bd92746edeb407ea664db 100644 (file)
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -3966,10 +3966,13 @@ void ReplicatedPG::repop_ack(RepGather *repop, int result, int ack_type,
 
 void ReplicatedPG::populate_obc_watchers(ObjectContext *obc)
 {
-  if (!is_active() || is_degraded_object(obc->obs.oi.soid) ||
-      is_missing_object(obc->obs.oi.soid))
+  if (!is_active() ||
+      is_missing_object(obc->obs.oi.soid)) {
+    dout(10) << "populate_obc_watchers " << obc->obs.oi.soid << " !active or missing, waiting" << dendl;
     return;
+  }
 
+  dout(10) << "populate_obc_watchers " << obc->obs.oi.soid << dendl;
   if (!obc->obs.oi.watchers.empty()) {
     Mutex::Locker l(osd->watch_lock);
     assert(obc->unconnected_watchers.size() == 0);