On Sun, Apr 05, 2015 at 07:20:19PM +0200, Pali Rohár wrote:

This patch adds dm message commands and option strings to optionally wipe key
from dm-crypt device before entering suspend or hibernate state.

 
Try to avoid 0/1 - use descriptive options instead. 
E.g. key wipe_on_hibernation / key retain_on_hibernation  (message)
     wipe_key_on_hiberation ('dmsetup table' - don't forget the reporting interface!)

Have you tested against every state the driver might be in at the time of
suspend/hibernation?

+static void crypt_suspend_and_wipe_key(struct crypt_config *cc)
+{
+	dm_suspend_md(dm_table_get_md(cc->ti->table));

I'm not particularly keen on this - silently ignoring expected error states
like -EINVAL rather than checking first and not calling the function at all
when it's known not to be needed.

Alasdair