1 files changed, 27 insertions, 0 deletions
diff --git a/drivers/md/bcache/bset.c b/drivers/md/bcache/bset.c
index 4a7113236034..7f8a7bd21503 100644
--- a/drivers/md/bcache/bset.c
+++ b/drivers/md/bcache/bset.c
@@ -773,6 +773,33 @@ static void bch_bset_fix_lookup_table(struct btree_keys *b,
 		}
 }
 
+/*
+ * Tries to merge l and r: l should be lower than r
+ * Returns true if we were able to merge. If we did merge, l will be the merged
+ * key, r will be untouched.
+ */
+bool bch_bkey_try_merge(struct btree_keys *b, struct bkey *l, struct bkey *r)
+{
+	if (!b->ops->key_merge)
+		return false;
+
+	/*
+	 * Generic header checks
+	 * Assumes left and right are in order
+	 * Left and right must be exactly aligned
+	 */
+	if (KEY_U64s(l) != KEY_U64s(r) ||
+	    KEY_DELETED(l) != KEY_DELETED(r) ||
+	    KEY_CACHED(l) != KEY_CACHED(r) ||
+	    KEY_VERSION(l) != KEY_VERSION(r) ||
+	    KEY_CSUM(l) != KEY_CSUM(r) ||
+	    bkey_cmp(l, &START_KEY(r)))
+		return false;
+
+	return b->ops->key_merge(b, l, r);
+}
+EXPORT_SYMBOL(bch_bkey_try_merge);
+
 void bch_bset_insert(struct btree_keys *b, struct bkey *where,
 		     struct bkey *insert)
 {