mon: MDSMonitor: Forbid removal of first data pool

Because inodes from other pools now store their backtrace
on the first/default data pool, it is special and may not
be removed.

Fixes: 7109
Signed-off-by: John Spray <john.spray@inktank.com>

diff --git a/src/mon/MDSMonitor.cc b/src/mon/MDSMonitor.cc
index 0f7bf274eb4591eb8df5ad941d43f75a05de085c..1e81eba9ad802b4c7734e1a6b1f6964a612b3cd6 100644 (file)
--- a/src/mon/MDSMonitor.cc
+++ b/src/mon/MDSMonitor.cc
@@ -1046,6 +1046,13 @@ bool MDSMonitor::prepare_command(MMonCommand *m)
        ss << "pool '" << poolname << "' does not exist";
       }
     }
+
+    if (pending_mdsmap.get_first_data_pool() == poolid) {
+      r = -EINVAL;
+      poolid = -1;
+      ss << "cannot remove default data pool";
+    }
+
     if (poolid >= 0) {
       cmd_getval(g_ceph_context, cmdmap, "poolid", poolid);
       r = pending_mdsmap.remove_data_pool(poolid);