--- zzzz-none-000/linux-3.10.107/drivers/md/dm-exception-store.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/md/dm-exception-store.c	2021-02-04 17:41:59.000000000 +0000
@@ -183,7 +183,7 @@
 
 	store->chunk_size = chunk_size;
 	store->chunk_mask = chunk_size - 1;
-	store->chunk_shift = ffs(chunk_size) - 1;
+	store->chunk_shift = __ffs(chunk_size);
 
 	return 0;
 }
@@ -203,7 +203,7 @@
 		return -EINVAL;
 	}
 
-	tmp_store = kmalloc(sizeof(*tmp_store), GFP_KERNEL);
+	tmp_store = kzalloc(sizeof(*tmp_store), GFP_KERNEL);
 	if (!tmp_store) {
 		ti->error = "Exception store allocation failed";
 		return -ENOMEM;
@@ -215,7 +215,7 @@
 	else if (persistent == 'N')
 		type = get_type("N");
 	else {
-		ti->error = "Persistent flag is not P or N";
+		ti->error = "Exception store type is not P or N";
 		r = -EINVAL;
 		goto bad_type;
 	}
@@ -233,7 +233,7 @@
 	if (r)
 		goto bad;
 
-	r = type->ctr(tmp_store, 0, NULL);
+	r = type->ctr(tmp_store, (strlen(argv[0]) > 1 ? &argv[0][1] : NULL));
 	if (r) {
 		ti->error = "Exception store type constructor failed";
 		goto bad;