From: Samuel Just <sjust@redhat.com>
Date: Thu, 28 Apr 2016 20:47:48 +0000 (-0700)
Subject: OSDMonitor: avoid underflow in reweight-by-utilization if max_change=1
X-Git-Tag: v0.94.7~1^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=76c33decdeba83d4d977a9556e76e68fa964465f;p=ceph.git

OSDMonitor: avoid underflow in reweight-by-utilization if max_change=1

Fixes: http://tracker.ceph.com/issues/15655
Signed-off-by: Samuel Just <sjust@redhat.com>
(cherry picked from commit c121bc51a5a877a49094cfbd3bd16af1f3ae5090)
---

diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index 8eadf0afe71e..f12f753b2222 100644
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -615,7 +615,8 @@ int OSDMonitor::reweight_by_utilization(int oload,
       // to represent e.g. differing storage capacities
       unsigned weight = osdmap.get_weight(p->first);
       unsigned new_weight = (unsigned)((average_util / util) * (float)weight);
-      new_weight = MAX(new_weight, weight - max_change);
+      if (weight > max_change)
+	new_weight = MAX(new_weight, weight - max_change);
       newinc.new_weight[p->first] = new_weight;
       if (!dry_run) {
 	pending_inc.new_weight[p->first] = new_weight;