From: Yan, Zheng <zyan@redhat.com>
Date: Wed, 29 Mar 2017 08:35:15 +0000 (+0800)
Subject: mon/MDSMonitor: only allow deactivating the mds with max rank
X-Git-Tag: v12.1.0~10^2~28^2~17
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=2c08f58ee8353322a342ce043150aafc8dd9c381;p=ceph.git

mon/MDSMonitor: only allow deactivating the mds with max rank

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
---

diff --git a/src/mds/MDSMap.h b/src/mds/MDSMap.h
index 1d8e29b2a36b..b7818437c29e 100644
--- a/src/mds/MDSMap.h
+++ b/src/mds/MDSMap.h
@@ -346,6 +346,10 @@ public:
   unsigned get_num_up_mds() const {
     return up.size();
   }
+  mds_rank_t get_last_in_mds() const {
+    auto p = in.rbegin();
+    return p == in.rend() ? MDS_RANK_NONE : *p;
+  }
   int get_num_failed_mds() const {
     return failed.size();
   }
diff --git a/src/mon/MDSMonitor.cc b/src/mon/MDSMonitor.cc
index 16e455295252..6a3b03437eb8 100644
--- a/src/mon/MDSMonitor.cc
+++ b/src/mon/MDSMonitor.cc
@@ -1328,6 +1328,10 @@ int MDSMonitor::filesystem_command(
       ss << "can't tell the root (" << fs->mds_map.get_root()
 	 << ") or tableserver (" << fs->mds_map.get_tableserver()
 	 << ") to deactivate";
+    } else if (role.rank != fs->mds_map.get_last_in_mds()) {
+      r = -EINVAL;
+      ss << "mds." << role << " doesn't have the max rank ("
+	 << fs->mds_map.get_last_in_mds() << ")";
     } else if (fs->mds_map.get_num_in_mds() <= size_t(fs->mds_map.get_max_mds())) {
       r = -EBUSY;
       ss << "must decrease max_mds or else MDS will immediately reactivate";