Re: [PATCH 08/25] btrfs: remove BUG_ON() in find_parent_nodes()

On Tue, Nov 23, 2021 at 10:53:07PM +0200, Nikolay Borisov wrote:

On 5.11.21 г. 22:45, Josef Bacik wrote:

quoted

We search for an extent entry with .offset = -1, which shouldn't be a
thing, but corruption happens.  Add an ASSERT() for the developers,
return -EUCLEAN for mortals.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/backref.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 12276ff08dd4..7d942f5d6443 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c

@@ -1210,7 +1210,12 @@ static int find_parent_nodes(struct btrfs_trans_handle *trans,
 	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
 	if (ret < 0)
 		goto out;
-	BUG_ON(ret == 0);
+	if (ret == 0) {
+		/* This shouldn't happen, indicates a bug or fs corruption. */
+		ASSERT(ret != 0);

This can never trigger in this branch, because ret is guaranteed to be 0
o_O?

It'll always trigger right?  ASSERT(false) == BUG_ON(true), and in this case ret
== 0, so we'll BUG_ON() in this case because it's wrong.  Thanks,

Jsoef