[PATCH 3.12 082/118] dm stats: initialize read-only module parameter

Greg Kroah-Hartman
2013-12-18T21:25:31Z

From: Mikulas Patocka <mpatocka@redhat.com>

commit 76f5bee5c3b45c617f91243e85547fc8f67bc678 upstream.

The module parameter stats_current_allocated_bytes in dm-mod is
read-only. This parameter informs the user about memory
consumption. It is not supposed to be changed by the user.

However, despite being read-only, this parameter can be set on
modprobe or insmod command line:
modprobe dm-mod stats_current_allocated_bytes=12345

The kernel doesn't expect that this variable can be non-zero at module
initialization and if the user sets it, it results in warning.

This patch initializes the variable in the module init routine, so
that user-supplied value is ignored.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/md/dm-stats.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/md/dm-stats.c
+++ b/drivers/md/dm-stats.c
@@ -964,6 +964,7 @@ int dm_stats_message(struct mapped_devic

int __init dm_statistics_init(void)
{
+ shared_memory_amount = 0;
dm_stat_need_rcu_barrier = 0;
return 0;
}