mon/MDSMonitor: return mon_mds_force_trim_to even if equal to current epoch

The PaxosService code already excludes the value returned by
PaxosService::get_trim_to as the upper bound of the range of epochs to
trim. Without this fix, you need to set mon_mds_force_trim_to to one
greater than the epoch you want to trim _and_ force the current epoch to
be one greater than that; the net result being that you can only force
trimming up to 2 epochs behind the current epoch.

This change is helpful for resolving issue 51673, but not strictly
necessary.

Related-to: https://tracker.ceph.com/issues/51673
Signed-off-by: Patrick Donnelly <pdonnell@redhat.com>
(cherry picked from commit d9dc2f11d56fb4341ba5823f8d17459d10f3b2c1)

Conflicts:
	src/common/options/mon.yaml.in: drop doc change

diff --git a/src/mon/MDSMonitor.cc b/src/mon/MDSMonitor.cc
index 994531da181c7c0690579c7ff8444acb034a5dc5..0ce59c79c41094e84c37bed2838031a7f9b4799a 100644 (file)
--- a/src/mon/MDSMonitor.cc
+++ b/src/mon/MDSMonitor.cc
@@ -264,7 +264,7 @@ version_t MDSMonitor::get_trim_to() const
 {
   version_t floor = 0;
   if (g_conf()->mon_mds_force_trim_to > 0 &&
-      g_conf()->mon_mds_force_trim_to < (int)get_last_committed()) {
+      g_conf()->mon_mds_force_trim_to <= (int)get_last_committed()) {
     floor = g_conf()->mon_mds_force_trim_to;
     dout(10) << __func__ << " explicit mon_mds_force_trim_to = "
              << floor << dendl;