osd: fix off-by-one in map gap logic

If we have map 250, and monitor's first is 251, but sends 260, we can
request the intervening range.

Fixes: #5784
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Samuel Just <sam.just@inktank.com>

diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index e3a7c227e155323cdf2828b8608494d1727a67da..3fd818e04e3d6122bdd07db22f2b6e7d00f03d9a 100644 (file)
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -4958,7 +4958,7 @@ void OSD::handle_osd_map(MOSDMap *m)
     dout(10) << "handle_osd_map message skips epochs " << osdmap->get_epoch() + 1
             << ".." << (first-1) << dendl;
     if ((m->oldest_map < first && osdmap->get_epoch() == 0) ||
-       m->oldest_map <= osdmap->get_epoch()) {
+       m->oldest_map <= osdmap->get_epoch() + 1) {
       monc->sub_want("osdmap", osdmap->get_epoch()+1, CEPH_SUBSCRIBE_ONETIME);
       monc->renew_subs();
       m->put();