thin: reworked thin feature detection

Rework thin feature detection to support runtime
section to allow to disable them selectively.

New lvm.conf option is born: global/thin_disabled_features

1 files changed, 10 insertions, 0 deletions

diff --git a/doc/example.conf.in b/doc/example.conf.in
index 1a3ee1b69..872d6ef16 100644
--- a/doc/example.conf.in
+++ b/doc/example.conf.in
@@ -524,6 +524,16 @@ global {
     # String with options passed with thin_check command. By default,
     # option '-q' is for quiet output.
     thin_check_options = [ "-q" ]
+
+    # If set, given features are not used by thin driver.
+    # This can be helpful not just for testing, but i.e. allows to avoid
+    # using problematic implementation of some thin feature.
+    # Features:
+    #   block_size
+    #   discards
+    #   discards_non_power_2
+    #
+    # thin_disabled_features = [ "discards", "block_size" ]
 }
 
 activation {