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Diffstat (limited to 'drivers/md/dm-cache-policy.h')
-rw-r--r--drivers/md/dm-cache-policy.h15
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/md/dm-cache-policy.h b/drivers/md/dm-cache-policy.h
index f50fe360c546..5524e21e4836 100644
--- a/drivers/md/dm-cache-policy.h
+++ b/drivers/md/dm-cache-policy.h
@@ -70,6 +70,18 @@ enum policy_operation {
};
/*
+ * When issuing a POLICY_REPLACE the policy needs to make a callback to
+ * lock the block being demoted. This doesn't need to occur during a
+ * writeback operation since the block remains in the cache.
+ */
+struct policy_locker;
+typedef int (*policy_lock_fn)(struct policy_locker *l, dm_oblock_t oblock);
+
+struct policy_locker {
+ policy_lock_fn fn;
+};
+
+/*
* This is the instruction passed back to the core target.
*/
struct policy_result {
@@ -122,7 +134,8 @@ struct dm_cache_policy {
*/
int (*map)(struct dm_cache_policy *p, dm_oblock_t oblock,
bool can_block, bool can_migrate, bool discarded_oblock,
- struct bio *bio, struct policy_result *result);
+ struct bio *bio, struct policy_locker *locker,
+ struct policy_result *result);
/*
* Sometimes we want to see if a block is in the cache, without