config: {thin,cache}_{check,repair}_options are never undefined

Require global/{thin,cache}_{check,repair}_options to be always defined.
If not defined directly by user in the configuration and if there's no
concrete default option to use, make "" (empty string) the default one -
it's then clearly visible in the "lvmconfig --type default" (and
generated lvm.conf) and also it makes its handling in the code more
straightforward so we don't need to handle undefined values.

This means, if there are no default values for these settings defined,
we end up with this generated now:
  {thin,cache}_{check,repair}_options = [ "" ]

So the value is never undefined and if it is, it's an error.

(The cache_repair_options is actually not used in the code at the moment,
but once the code using this setting is in, it will follow the same logic
as used for thin_repair_options.)

1 files changed, 2 insertions, 2 deletions

diff --git a/conf/example.conf.in b/conf/example.conf.in
index 320795566..3900ad41b 100644
--- a/conf/example.conf.in
+++ b/conf/example.conf.in
@@ -876,7 +876,7 @@ global {
 
 	# Configuration option global/thin_repair_options.
 	# List of options passed to the thin_repair command.
-	# This configuration option does not have a default value defined.
+	# thin_repair_options = [ "" ]
 
 	# Configuration option global/thin_disabled_features.
 	# Features to not use in the thin driver.
@@ -924,7 +924,7 @@ global {
 
 	# Configuration option global/cache_repair_options.
 	# List of options passed to the cache_repair command.
-	# This configuration option does not have a default value defined.
+	# cache_repair_options = [ "" ]
 
 	# Configuration option global/system_id_source.
 	# The method LVM uses to set the local system ID.