From: Sage Weil <sage@redhat.com>
Date: Sat, 15 Sep 2018 19:51:22 +0000 (-0500)
Subject: mon/OSDMonitor: handle ready_to_merge message that cancels the merge
X-Git-Tag: v14.0.1~212^2~4
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=6c6cf6360cb6dd9eecc77ea73f639b1c0c0b1ac5;p=ceph.git

mon/OSDMonitor: handle ready_to_merge message that cancels the merge

Signed-off-by: Sage Weil <sage@redhat.com>
---

diff --git a/src/messages/MOSDPGReadyToMerge.h b/src/messages/MOSDPGReadyToMerge.h
index b286686b761b7..c07c58f4b3ba1 100644
--- a/src/messages/MOSDPGReadyToMerge.h
+++ b/src/messages/MOSDPGReadyToMerge.h
@@ -8,31 +8,36 @@ class MOSDPGReadyToMerge
 public:
   pg_t pgid;
   epoch_t last_epoch_clean = 0;
+  bool ready = true;
 
   MOSDPGReadyToMerge()
     : MessageInstance(MSG_OSD_PG_READY_TO_MERGE, 0)
   {}
-  MOSDPGReadyToMerge(pg_t p, epoch_t lec, epoch_t v)
+  MOSDPGReadyToMerge(pg_t p, epoch_t lec, bool r, epoch_t v)
     : MessageInstance(MSG_OSD_PG_READY_TO_MERGE, v),
       pgid(p),
-      last_epoch_clean(lec)
+      last_epoch_clean(lec),
+      ready(r)
   {}
   void encode_payload(uint64_t features) override {
     using ceph::encode;
     paxos_encode();
     encode(pgid, payload);
     encode(last_epoch_clean, payload);
+    encode(ready, payload);
   }
   void decode_payload() override {
     bufferlist::const_iterator p = payload.begin();
     paxos_decode(p);
     decode(pgid, p);
     decode(last_epoch_clean, p);
+    decode(ready, p);
   }
   const char *get_type_name() const override { return "osd_pg_ready_to_merge"; }
   void print(ostream &out) const {
     out << get_type_name()
         << "(" << pgid << " lec " << last_epoch_clean
+	<< (ready ? " ready" : " NOT READY")
         << " v" << version << ")";
   }
 };
diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index ac2eb6ee6870b..5ef006ee1f41d 100644
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -3295,8 +3295,13 @@ bool OSDMonitor::prepare_pg_ready_to_merge(MonOpRequestRef op)
     return true;
   }
 
-  p.dec_pg_num(m->last_epoch_clean);
-  p.last_change = pending_inc.epoch;
+  if (m->ready) {
+    p.dec_pg_num(m->last_epoch_clean);
+    p.last_change = pending_inc.epoch;
+  } else {
+    // back off the merge attempt!
+    p.set_pg_num_pending(p.get_pg_num());
+  }
 
   // force pre-nautilus clients to resend their ops, since they
   // don't understand pg_num_pending changes form a new interval
@@ -3305,7 +3310,9 @@ bool OSDMonitor::prepare_pg_ready_to_merge(MonOpRequestRef op)
   pending_inc.new_pools[m->pgid.pool()] = p;
 
   auto prob = g_conf().get_val<double>("mon_inject_pg_merge_bounce_probability");
-  if (prob > 0 && prob > (double)(rand() % 1000)/1000.0) {
+  if (m->ready &&
+      prob > 0 &&
+      prob > (double)(rand() % 1000)/1000.0) {
     derr << __func__ << " injecting pg merge pg_num bounce" << dendl;
     auto n = new MMonCommand(mon->monmap->get_fsid());
     n->set_connection(m->get_connection());
diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index cffc61739436c..671034e4be8b2 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -1725,6 +1725,7 @@ void OSDService::_send_ready_to_merge()
       monc->send_mon_message(new MOSDPGReadyToMerge(
 			       src,
 			       p->second,  // PG's last_epoch_clean
+			       true,
 			       osdmap->get_epoch()));
       sent_ready_to_merge_source.insert(src);
     }