dm cache: policy change version from string to integer set
Separate dm cache policy version string into 3 unsigned numbers
corresponding to major, minor and patchlevel and store them at the end
of the on-disk metadata so we know which version of the policy generated
the hints in case a future version wants to use them differently.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-cache-policy-mq.c b/drivers/md/dm-cache-policy-mq.c
index 9641532..dc112a7 100644
--- a/drivers/md/dm-cache-policy-mq.c
+++ b/drivers/md/dm-cache-policy-mq.c
@@ -14,7 +14,6 @@
#include <linux/vmalloc.h>
#define DM_MSG_PREFIX "cache-policy-mq"
-#define MQ_VERSION "1.0.0"
static struct kmem_cache *mq_entry_cache;
@@ -1133,6 +1132,7 @@
static struct dm_cache_policy_type mq_policy_type = {
.name = "mq",
+ .version = {1, 0, 0},
.hint_size = 4,
.owner = THIS_MODULE,
.create = mq_create
@@ -1140,6 +1140,7 @@
static struct dm_cache_policy_type default_policy_type = {
.name = "default",
+ .version = {1, 0, 0},
.hint_size = 4,
.owner = THIS_MODULE,
.create = mq_create
@@ -1164,7 +1165,10 @@
r = dm_cache_policy_register(&default_policy_type);
if (!r) {
- DMINFO("version " MQ_VERSION " loaded");
+ DMINFO("version %u.%u.%u loaded",
+ mq_policy_type.version[0],
+ mq_policy_type.version[1],
+ mq_policy_type.version[2]);
return 0;
}