From 3046d17f61d1fa11fe2f35f7cfe9428312a78593 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@redhat.com>
Date: Tue, 2 Apr 2019 16:50:08 -0500
Subject: [PATCH] mon/MonmapMonitor: clean up empty created stamp in monmap

Some old clusters have an empty created timestamp.  This is mostly
harmless, but it is confusing/wrong, and it does currently break the
telemetry module with errors like

 ValueError: time data '0.000000' does not match format '%Y-%m-%d %H:%M:%S.%f'

from 'ceph telemetry show'.

If we detect an empty created stamp, look at old monmap and use the oldest
modified stamp we can find.

Fixes: http://tracker.ceph.com/issues/39085
Signed-off-by: Sage Weil <sage@redhat.com>
---
 src/mon/MonmapMonitor.cc | 35 +++++++++++++++++++++++++++++++++++
 src/mon/MonmapMonitor.h  |  2 ++
 2 files changed, 37 insertions(+)

diff --git a/src/mon/MonmapMonitor.cc b/src/mon/MonmapMonitor.cc
index 2497dadd4f7..f15a36185df 100644
--- a/src/mon/MonmapMonitor.cc
+++ b/src/mon/MonmapMonitor.cc
@@ -928,3 +928,38 @@ void MonmapMonitor::check_sub(Subscription *sub)
     }
   }
 }
+
+void MonmapMonitor::tick()
+{
+  if (!is_active() ||
+      !mon->is_leader()) {
+    return;
+  }
+
+  if (mon->monmap->created.is_zero()) {
+    dout(10) << __func__ << " detected empty created stamp" << dendl;
+    utime_t ctime;
+    for (version_t v = 1; v <= get_last_committed(); v++) {
+      bufferlist bl;
+      int r = get_version(v, bl);
+      if (r < 0) {
+	continue;
+      }
+      MonMap m;
+      auto p = bl.cbegin();
+      decode(m, p);
+      if (!m.last_changed.is_zero()) {
+	dout(10) << __func__ << " first monmap with last_changed is "
+		 << v << " with " << m.last_changed << dendl;
+	ctime = m.last_changed;
+	break;
+      }
+    }
+    if (ctime.is_zero()) {
+      ctime = ceph_clock_now();
+    }
+    dout(10) << __func__ << " updating created stamp to " << ctime << dendl;
+    pending_map.created = ctime;
+    propose_pending();
+  }
+}
diff --git a/src/mon/MonmapMonitor.h b/src/mon/MonmapMonitor.h
index ced31e8d3e1..fc0bfdbde22 100644
--- a/src/mon/MonmapMonitor.h
+++ b/src/mon/MonmapMonitor.h
@@ -72,6 +72,8 @@ class MonmapMonitor : public PaxosService {
 
   void check_sub(Subscription *sub);
 
+  void tick() override;
+
 private:
   void check_subs();
   bufferlist monmap_bl;