dm persistent data: remove debug space map checker

Remove debug space map checker from dm persistent data.

The space map checker is a wrapper for other space maps that double
checks the reference counts are correct.  It holds all these reference
counts in memory rather than on disk, so uses a lot of memory and is
thus restricted to small pools.

As yet, this checker hasn't found any issues, but has caused a few of
its own due to people turning it on by default with larger pools.

Removing.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 0 insertions, 9 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 10f122a3a856..1eee45b69b71 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -260,15 +260,6 @@ config DM_DEBUG_BLOCK_STACK_TRACING
 
           If unsure, say N.
 
-config DM_DEBUG_SPACE_MAPS
-        boolean "Extra validation for thin provisioning space maps"
-        depends on DM_THIN_PROVISIONING
-        ---help---
-          Enable this for messages that may help debug problems with the
-          space maps used by thin provisioning.
-
-          If unsure, say N.
-
 config DM_MIRROR
        tristate "Mirror target"
        depends on BLK_DEV_DM