osd: subscribe osdmaps if any pending pgs

subscribe from monitor continously for new osdmaps so osd is able to get
the osdmap instructing it to delete PGs even if nobody is poking it.

Fixes: http://tracker.ceph.com/issues/22113
Signed-off-by: Kefu Chai <kchai@redhat.com>

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 298b95b73d2d5681ee21c46a361dc3d5d4faaf60..c49477aec22bc6d34feda01c54f5009bfe0b1430 100644 (file)
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -4185,6 +4185,7 @@ static vector<int32_t> twiddle(const vector<int>& acting) {
 void OSD::resume_creating_pg()
 {
   bool do_sub_pg_creates = false;
+  bool have_pending_creates = false;
   MOSDPGTemp *pgtemp = nullptr;
   {
     const auto max_pgs_per_osd =
@@ -4217,14 +4218,40 @@ void OSD::resume_creating_pg()
       pg = pending_creates_from_osd.erase(pg);
       spare_pgs--;
     }
+    have_pending_creates = (pending_creates_from_mon > 0 ||
+                           !pending_creates_from_osd.empty());
   }
+
+  bool do_renew_subs = false;
   if (do_sub_pg_creates) {
     if (monc->sub_want("osd_pg_creates", last_pg_create_epoch, 0)) {
       dout(4) << __func__ << ": resolicit pg creates from mon since "
              << last_pg_create_epoch << dendl;
-      monc->renew_subs();
+      do_renew_subs = true;
+    }
+  }
+  version_t start = osdmap->get_epoch() + 1;
+  if (have_pending_creates) {
+    // don't miss any new osdmap deleting PGs
+    if (monc->sub_want("osdmap", start, 0)) {
+      dout(4) << __func__ << ": resolicit osdmap from mon since "
+             << start << dendl;
+      do_renew_subs = true;
+    }
+  } else if (pgtemp || do_sub_pg_creates) {
+    // no need to subscribe the osdmap continuously anymore
+    // once the pgtemp and/or mon_subscribe(pg_creates) is sent
+    if (monc->sub_want_increment("osdmap", start, CEPH_SUBSCRIBE_ONETIME)) {
+      dout(4) << __func__ << ": re-subscribe osdmap(onetime) since"
+             << start << dendl;
+      do_renew_subs = true;
     }
   }
+
+  if (do_renew_subs) {
+    monc->renew_subs();
+  }
+
   if (pgtemp) {
     pgtemp->forced = true;
     monc->send_mon_message(pgtemp);