NEO: enable cksumvfs by default

This is not backward compatible: you'll need to either fix your DB
or disable explicitly.

software/neoppod/buildout.hash.cfg

@@ -30,7 +30,7 @@ md5sum = 9f27195d770b2f57461c60a82c851ab9
 
 [instance-neo]
 filename = instance-neo.cfg.in
-md5sum = bc647a29f9d6ece2e4117ce8f04d27c5
+md5sum = 9bfb9e94363d63b801b29e559b7a0c8d
 
 [template-neo-my-cnf]
 filename = my.cnf.in

software/neoppod/instance-neo-input-schema.json

@@ -133,6 +133,15 @@
                   "description": "When enabled, sets synchronous = OFF and journal_mode = MEMORY - RTFM, those options are dangerous.",
                   "default": false,
                   "type": "boolean"
+                },
+                "cksumvfs": {
+                  "description": "See https://www.sqlite.org/cksumvfs.html. It can be safely disabled if the underlying storage layer is already checksumming, e.g. Btrfs (on this FS, you should also set journal_mode=TRUNCATE).",
+                  "default": 1,
+                  "type": "integer",
+                  "enum": [
+                    0,
+                    1
+                  ]
                 }
               },
               "additionalProperties": {

software/neoppod/instance-neo.cfg.in

@@ -79,6 +79,9 @@ command = mysql
 {% elif storage_type == 'SQLite' -%}
 {%   set extra_dict = slapparameter_dict.get('sqlite') or {} -%}
 
+{%   if extra_dict.setdefault('cksumvfs', 1) == 0 -%}
+{%     do extra_dict.pop('cksumvfs') -%}
+{%   endif -%}
 {%   if extra_dict.pop('relaxed-writes', False) -%}
 {%     do extra_dict.setdefault('synchronous', 'OFF') -%}
 {%     do extra_dict.setdefault('journal_mode', 'MEMORY') -%}