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Diffstat (limited to 'drivers/md/dm-cache-policy.h')
-rw-r--r--drivers/md/dm-cache-policy.h27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/md/dm-cache-policy.h b/drivers/md/dm-cache-policy.h
index 33369ca9614..f50fe360c54 100644
--- a/drivers/md/dm-cache-policy.h
+++ b/drivers/md/dm-cache-policy.h
@@ -135,9 +135,6 @@ struct dm_cache_policy {
*/
int (*lookup)(struct dm_cache_policy *p, dm_oblock_t oblock, dm_cblock_t *cblock);
- /*
- * oblock must be a mapped block. Must not block.
- */
void (*set_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
void (*clear_dirty)(struct dm_cache_policy *p, dm_oblock_t oblock);
@@ -159,8 +156,24 @@ struct dm_cache_policy {
void (*force_mapping)(struct dm_cache_policy *p, dm_oblock_t current_oblock,
dm_oblock_t new_oblock);
- int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock);
+ /*
+ * This is called via the invalidate_cblocks message. It is
+ * possible the particular cblock has already been removed due to a
+ * write io in passthrough mode. In which case this should return
+ * -ENODATA.
+ */
+ int (*remove_cblock)(struct dm_cache_policy *p, dm_cblock_t cblock);
+ /*
+ * Provide a dirty block to be written back by the core target.
+ *
+ * Returns:
+ *
+ * 0 and @cblock,@oblock: block to write back provided
+ *
+ * -ENODATA: no dirty blocks available
+ */
+ int (*writeback_work)(struct dm_cache_policy *p, dm_oblock_t *oblock, dm_cblock_t *cblock);
/*
* How full is the cache?
@@ -210,6 +223,12 @@ struct dm_cache_policy_type {
unsigned version[CACHE_POLICY_VERSION_SIZE];
/*
+ * For use by an alias dm_cache_policy_type to point to the
+ * real dm_cache_policy_type.
+ */
+ struct dm_cache_policy_type *real;
+
+ /*
* Policies may store a hint for each each cache block.
* Currently the size of this hint must be 0 or 4 bytes but we
* expect to relax this in future.