1 files changed, 12 insertions, 33 deletions

diff --git a/drivers/md/dm-cache-policy-smq.c b/drivers/md/dm-cache-policy-smq.c
index cf48a617a3a4..c33f4a6e1d7d 100644
--- a/drivers/md/dm-cache-policy-smq.c
+++ b/drivers/md/dm-cache-policy-smq.c
@@ -1359,6 +1359,11 @@ static void smq_clear_dirty(struct dm_cache_policy *p, dm_oblock_t oblock)
 	spin_unlock_irqrestore(&mq->lock, flags);
 }
 
+static unsigned random_level(dm_cblock_t cblock)
+{
+	return hash_32_generic(from_cblock(cblock), 9) & (NR_CACHE_LEVELS - 1);
+}
+
 static int smq_load_mapping(struct dm_cache_policy *p,
 			    dm_oblock_t oblock, dm_cblock_t cblock,
 			    uint32_t hint, bool hint_valid)
@@ -1369,47 +1374,21 @@ static int smq_load_mapping(struct dm_cache_policy *p,
 	e = alloc_particular_entry(&mq->cache_alloc, from_cblock(cblock));
 	e->oblock = oblock;
 	e->dirty = false;	/* this gets corrected in a minute */
-	e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : 1;
+	e->level = hint_valid ? min(hint, NR_CACHE_LEVELS - 1) : random_level(cblock);
 	push(mq, e);
 
 	return 0;
 }
 
-static int smq_save_hints(struct smq_policy *mq, struct queue *q,
-			  policy_walk_fn fn, void *context)
-{
-	int r;
-	unsigned level;
-	struct entry *e;
-
-	for (level = 0; level < q->nr_levels; level++)
-		for (e = l_head(q->es, q->qs + level); e; e = l_next(q->es, e)) {
-			if (!e->sentinel) {
-				r = fn(context, infer_cblock(mq, e),
-				       e->oblock, e->level);
-				if (r)
-					return r;
-			}
-		}
-
-	return 0;
-}
-
-static int smq_walk_mappings(struct dm_cache_policy *p, policy_walk_fn fn,
-			     void *context)
+static uint32_t smq_get_hint(struct dm_cache_policy *p, dm_cblock_t cblock)
 {
 	struct smq_policy *mq = to_smq_policy(p);
-	int r = 0;
+	struct entry *e = get_entry(&mq->cache_alloc, from_cblock(cblock));
 
-	/*
-	 * We don't need to lock here since this method is only called once
-	 * the IO has stopped.
-	 */
-	r = smq_save_hints(mq, &mq->clean, fn, context);
-	if (!r)
-		r = smq_save_hints(mq, &mq->dirty, fn, context);
+	if (!e->allocated)
+		return 0;
 
-	return r;
+	return e->level;
 }
 
 static void __remove_mapping(struct smq_policy *mq, dm_oblock_t oblock)
@@ -1616,7 +1595,7 @@ static void init_policy_functions(struct smq_policy *mq, bool mimic_mq)
 	mq->policy.set_dirty = smq_set_dirty;
 	mq->policy.clear_dirty = smq_clear_dirty;
 	mq->policy.load_mapping = smq_load_mapping;
-	mq->policy.walk_mappings = smq_walk_mappings;
+	mq->policy.get_hint = smq_get_hint;
 	mq->policy.remove_mapping = smq_remove_mapping;
 	mq->policy.remove_cblock = smq_remove_cblock;
 	mq->policy.writeback_work = smq_writeback_work;