From: Kent Overstreet <kent.overstreet@linux.dev>
Date: Mon, 13 Feb 2023 23:21:40 +0000 (-0500)
Subject: bcachefs: Fix verify_update_old_key()
X-Git-Tag: io_uring-6.7-2023-11-10~119^2~512
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=70f0b0fd7e9b85a14fdb8b3f229572b7439d8915;p=linux-block.git

bcachefs: Fix verify_update_old_key()

This fixes a very-rare race in our assertion, with needs_whiteout being
modified in the btree key.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
---

diff --git a/fs/bcachefs/btree_update_leaf.c b/fs/bcachefs/btree_update_leaf.c
index cefe62d28cc0..3773439d031a 100644
--- a/fs/bcachefs/btree_update_leaf.c
+++ b/fs/bcachefs/btree_update_leaf.c
@@ -56,9 +56,10 @@ static void verify_update_old_key(struct btree_trans *trans, struct btree_insert
 			k = bkey_i_to_s_c(j_k);
 	}
 
-	i->old_k.needs_whiteout = k.k->needs_whiteout;
+	u = *k.k;
+	u.needs_whiteout = i->old_k.needs_whiteout;
 
-	BUG_ON(memcmp(&i->old_k, k.k, sizeof(struct bkey)));
+	BUG_ON(memcmp(&i->old_k, &u, sizeof(struct bkey)));
 	BUG_ON(i->old_v != k.v);
 #endif
 }