bcache: Remove unnecessary NULL point check in node allocations

Due to the previous fix of __bch_btree_node_alloc, the return value will
never be a NULL pointer. So IS_ERR is enough to handle the failure
situation. Fix it by replacing IS_ERR_OR_NULL check by an IS_ERR check.

Fixes: cafe563 ("bcache: A block layer cache")
Cc: stable@vger.kernel.org
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20230615121223.22502-5-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/md/bcache/btree.c

@@ -1138,7 +1138,7 @@ static struct btree *btree_node_alloc_replacement(struct btree *b,
 {
 	struct btree *n = bch_btree_node_alloc(b->c, op, b->level, b->parent);
 
-	if (!IS_ERR_OR_NULL(n)) {
+	if (!IS_ERR(n)) {
 		mutex_lock(&n->write_lock);
 		bch_btree_sort_into(&b->keys, &n->keys, &b->c->sort);
 		bkey_copy_key(&n->key, &b->key);
@@ -1340,7 +1340,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
 	memset(new_nodes, 0, sizeof(new_nodes));
 	closure_init_stack(&cl);
 
-	while (nodes < GC_MERGE_NODES && !IS_ERR_OR_NULL(r[nodes].b))
+	while (nodes < GC_MERGE_NODES && !IS_ERR(r[nodes].b))
 		keys += r[nodes++].keys;
 
 	blocks = btree_default_blocks(b->c) * 2 / 3;
@@ -1352,7 +1352,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
 
 	for (i = 0; i < nodes; i++) {
 		new_nodes[i] = btree_node_alloc_replacement(r[i].b, NULL);
-		if (IS_ERR_OR_NULL(new_nodes[i]))
+		if (IS_ERR(new_nodes[i]))
 			goto out_nocoalesce;
 	}
 
@@ -1487,7 +1487,7 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
 	bch_keylist_free(&keylist);
 
 	for (i = 0; i < nodes; i++)
-		if (!IS_ERR_OR_NULL(new_nodes[i])) {
+		if (!IS_ERR(new_nodes[i])) {
 			btree_node_free(new_nodes[i]);
 			rw_unlock(true, new_nodes[i]);
 		}
@@ -1669,7 +1669,7 @@ static int bch_btree_gc_root(struct btree *b, struct btree_op *op,
 	if (should_rewrite) {
 		n = btree_node_alloc_replacement(b, NULL);
 
-		if (!IS_ERR_OR_NULL(n)) {
+		if (!IS_ERR(n)) {
 			bch_btree_node_write_sync(n);
 
 			bch_btree_set_root(n);

drivers/md/bcache/super.c

@@ -1723,7 +1723,7 @@ static void cache_set_flush(struct closure *cl)
 	if (!IS_ERR_OR_NULL(c->gc_thread))
 		kthread_stop(c->gc_thread);
 
-	if (!IS_ERR_OR_NULL(c->root))
+	if (!IS_ERR(c->root))
 		list_add(&c->root->list, &c->btree_cache);
 
 	/*
@@ -2087,7 +2087,7 @@ static int run_cache_set(struct cache_set *c)
 
 		err = "cannot allocate new btree root";
 		c->root = __bch_btree_node_alloc(c, NULL, 0, true, NULL);
-		if (IS_ERR_OR_NULL(c->root))
+		if (IS_ERR(c->root))
 			goto err;
 
 		mutex_lock(&c->root->write_lock);