[pve-devel] [PATCH storage] fix #1063: wait for librbd timeout when removing image

[Fabian Grünbichler]

upon a client crash/kill, there is a 30 second timeout until
the associated watcher is removed. until then, removing the
image is not possible.

krbd does not suffer from this, because "rbd map/unmap"
makes the watcher creation and destruction explicit.
---
Note: the pve-access-control patch series for worker stopping
is not strictly required for this to work, but makes the
user experience a lot better.

 PVE/Storage/RBDPlugin.pm | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/PVE/Storage/RBDPlugin.pm b/PVE/Storage/RBDPlugin.pm
index 7a08ff5..96b41e5 100644
--- a/PVE/Storage/RBDPlugin.pm
+++ b/PVE/Storage/RBDPlugin.pm
@@ -458,7 +458,18 @@ sub free_image {
     run_rbd_command($cmd, errmsg => "rbd snap purge '$volname' error");
 
     $cmd = &$rbd_cmd($scfg, $storeid, 'rm', $name);
-    run_rbd_command($cmd, errmsg => "rbd rm '$volname' error");
+    eval {
+	run_rbd_command($cmd, errmsg => "rbd rm '$volname' error");
+    };
+    my $err = $@;
+
+    if ($err && !$scfg->{krbd} && $err =~ m/image still has watchers$/) {
+	warn "Waiting 30s for rbd client to timeout before removing\n";
+	sleep 30;
+	run_rbd_command($cmd, errmsg => "rbd rm '$volname' error");
+    } else {
+	die $err if $err;
+    }
 
     return undef;
 }
-- 
2.1.4