bcache: Clean up keylist code

More random refactoring.

Signed-off-by: Kent Overstreet <kmo@daterainc.com>
diff --git a/drivers/md/bcache/bset.h b/drivers/md/bcache/bset.h
index a3627d0..8a93056 100644
--- a/drivers/md/bcache/bset.h
+++ b/drivers/md/bcache/bset.h
@@ -227,20 +227,23 @@
 /* Keylists */
 
 struct keylist {
-	struct bkey		*top;
 	union {
-		uint64_t		*list;
-		struct bkey		*bottom;
+		struct bkey		*keys;
+		uint64_t		*keys_p;
+	};
+	union {
+		struct bkey		*top;
+		uint64_t		*top_p;
 	};
 
 	/* Enough room for btree_split's keys without realloc */
 #define KEYLIST_INLINE		16
-	uint64_t		d[KEYLIST_INLINE];
+	uint64_t		inline_keys[KEYLIST_INLINE];
 };
 
 static inline void bch_keylist_init(struct keylist *l)
 {
-	l->top = (void *) (l->list = l->d);
+	l->top_p = l->keys_p = l->inline_keys;
 }
 
 static inline void bch_keylist_push(struct keylist *l)
@@ -256,16 +259,30 @@
 
 static inline bool bch_keylist_empty(struct keylist *l)
 {
-	return l->top == (void *) l->list;
+	return l->top == l->keys;
+}
+
+static inline void bch_keylist_reset(struct keylist *l)
+{
+	l->top = l->keys;
 }
 
 static inline void bch_keylist_free(struct keylist *l)
 {
-	if (l->list != l->d)
-		kfree(l->list);
+	if (l->keys_p != l->inline_keys)
+		kfree(l->keys_p);
 }
 
-void bch_keylist_copy(struct keylist *, struct keylist *);
+static inline size_t bch_keylist_nkeys(struct keylist *l)
+{
+	return l->top_p - l->keys_p;
+}
+
+static inline size_t bch_keylist_bytes(struct keylist *l)
+{
+	return bch_keylist_nkeys(l) * sizeof(uint64_t);
+}
+
 struct bkey *bch_keylist_pop(struct keylist *);
 void bch_keylist_pop_front(struct keylist *);
 int bch_keylist_realloc(struct keylist *, int, struct cache_set *);