diff --git a/fs/bcachefs/io_read.c b/fs/bcachefs/io_read.c
index 3c574d8873a1..8a556e6d1ab6 100644
--- a/fs/bcachefs/io_read.c
+++ b/fs/bcachefs/io_read.c
@@ -174,7 +174,7 @@ static struct promote_op *__promote_alloc(struct btree_trans *trans,
 	if (!bch2_write_ref_tryget(c, BCH_WRITE_REF_promote))
 		return ERR_PTR(-BCH_ERR_nopromote_no_writes);
 
-	op = kzalloc(sizeof(*op) + sizeof(struct bio_vec) * pages, GFP_KERNEL);
+	op = kzalloc(struct_size(op, bi_inline_vecs, pages), GFP_KERNEL);
 	if (!op) {
 		ret = -BCH_ERR_nopromote_enomem;
 		goto err;
diff --git a/fs/bcachefs/journal_seq_blacklist.c b/fs/bcachefs/journal_seq_blacklist.c
index 5acc1276675c..b5303874fc35 100644
--- a/fs/bcachefs/journal_seq_blacklist.c
+++ b/fs/bcachefs/journal_seq_blacklist.c
@@ -141,8 +141,7 @@ int bch2_blacklist_table_initialize(struct bch_fs *c)
 	if (!bl)
 		return 0;
 
-	t = kzalloc(sizeof(*t) + sizeof(t->entries[0]) * nr,
-		    GFP_KERNEL);
+	t = kzalloc(struct_size(t, entries, nr), GFP_KERNEL);
 	if (!t)
 		return -BCH_ERR_ENOMEM_blacklist_table_init;