From a62d7bd966ae6ad64c5dbc77db2e2a1ecb692729 Mon Sep 17 00:00:00 2001
From: Thomas Lamprecht <t.lamprecht@proxmox.com>
Date: Fri, 23 Nov 2018 18:49:46 +0100
Subject: [PATCH] api: cephfs: wait for MDS to become active

A MDS gets only active once a FS is there, and we need an MDS active
to be able to add a storage, as the CephFS plugin does an immediate
mount check. As an MDS needs some time to get active we had a
problematic time window where this mounting could fail.

Wait for a MDS to get in active state.

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
---
 PVE/API2/Ceph/FS.pm | 15 ++++++++++++++-
 PVE/CephTools.pm    | 18 ++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/PVE/API2/Ceph/FS.pm b/PVE/API2/Ceph/FS.pm
index a76d6a56..f934bbc1 100644
--- a/PVE/API2/Ceph/FS.pm
+++ b/PVE/API2/Ceph/FS.pm
@@ -185,9 +185,22 @@ __PACKAGE__->register_method ({
 
 		die "$err\n";
 	    }
+	    print "Successfully create CephFS '$fs_name'\n";
 
 	    if ($param->{add_storage}) {
-		my $err;
+		print "Adding '$fs_name' to storage configuration...\n";
+
+		my $waittime = 0;
+		while (!PVE::CephTools::is_any_mds_active()) {
+		    if ($waittime >= 10) {
+			die "Need MDS to add storage, but none got active!\n";
+		    }
+
+		    print "Waiting for an MDS to become active\n";
+		    sleep(1);
+		    $waittime++;
+		}
+
 		eval {
 		    PVE::API2::Storage::Config->create({
 			type => 'cephfs',
diff --git a/PVE/CephTools.pm b/PVE/CephTools.pm
index 825fc22f..d80e2b65 100644
--- a/PVE/CephTools.pm
+++ b/PVE/CephTools.pm
@@ -364,6 +364,24 @@ sub get_cluster_mds_state {
     return $mds_state;
 }
 
+sub is_any_mds_active {
+    my ($rados) = @_;
+
+    if (!defined($rados)) {
+	$rados = PVE::RADOS->new();
+    }
+
+    my $mds_dump = $rados->mon_command({ prefix => 'mds stat' });
+    my $fs = $mds_dump->{fsmap}->{filesystems};
+
+    if (!($fs && scalar(@$fs) > 0)) {
+	return undef;
+    }
+    my $active_mds = $fs->[0]->{mdsmap}->{info};
+
+    return scalar(keys %$active_mds) > 0;
+}
+
 sub create_mds {
     my ($id, $rados) = @_;