From: John Spray <john.spray@redhat.com>
Date: Thu, 9 Aug 2018 11:03:51 +0000 (-0400)
Subject: mon: fix idempotent FS creation
X-Git-Tag: v14.0.1~548^2
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=9d4d2ccc1a46346b10d5ee820a6bd992ed56fe23;p=ceph.git

mon: fix idempotent FS creation

In the case that our creation is a no-op, we should tolerate
objects in the metadata pool -- since we're not performing
any action, we can't do harm.

This case comes up if you have MDS daemons starting immediately
on filesystem creation: running the `fs new` command twice will fail
the second time because of the objects the MDS created.

Signed-off-by: John Spray <john.spray@redhat.com>
---

diff --git a/src/mon/FSCommands.cc b/src/mon/FSCommands.cc
index 6c0bab874b00c..ca1e227b003cb 100644
--- a/src/mon/FSCommands.cc
+++ b/src/mon/FSCommands.cc
@@ -105,19 +105,6 @@ class FsNewHandler : public FileSystemCommandHandler
       return -ENOENT;
     }
 
-    string force_str;
-    cmd_getval_throws(g_ceph_context,cmdmap, "force", force_str);
-    bool force = (force_str == "--force");
-    const pool_stat_t *stat = mon->mgrstatmon()->get_pool_stat(metadata);
-    if (stat) {
-      int64_t metadata_num_objects = stat->stats.sum.num_objects;
-      if (!force && metadata_num_objects > 0) {
-	ss << "pool '" << metadata_name
-	   << "' already contains some objects. Use an empty pool instead.";
-	return -EINVAL;
-      }
-    }
-
     string data_name;
     cmd_getval_throws(g_ceph_context, cmdmap, "data", data_name);
     int64_t data = mon->osdmon()->osdmap.lookup_pg_pool_name(data_name);
@@ -152,6 +139,19 @@ class FsNewHandler : public FileSystemCommandHandler
       }
     }
 
+    string force_str;
+    cmd_getval_throws(g_ceph_context,cmdmap, "force", force_str);
+    bool force = (force_str == "--force");
+    const pool_stat_t *stat = mon->mgrstatmon()->get_pool_stat(metadata);
+    if (stat) {
+      int64_t metadata_num_objects = stat->stats.sum.num_objects;
+      if (!force && metadata_num_objects > 0) {
+	ss << "pool '" << metadata_name
+	   << "' already contains some objects. Use an empty pool instead.";
+	return -EINVAL;
+      }
+    }
+
     if (fsmap.filesystem_count() > 0
         && !fsmap.get_enable_multiple()) {
       ss << "Creation of multiple filesystems is disabled.  To enable "