From 28062cd6eda04035d8f6ded2001292ac8b496149 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Tue, 1 Aug 2023 19:02:28 +0800 Subject: [PATCH] btrfs: output extra debug info if we failed to find an inline backref [ Upstream commit 7f72f50547b7af4ddf985b07fc56600a4deba281 ] [BUG] Syzbot reported several warning triggered inside lookup_inline_extent_backref(). [CAUSE] As usual, the reproducer doesn't reliably trigger locally here, but at least we know the WARN_ON() is triggered when an inline backref can not be found, and it can only be triggered when @insert is true. (I.e. inserting a new inline backref, which means the backref should already exist) [ENHANCEMENT] After the WARN_ON(), dump all the parameters and the extent tree leaf to help debug. Link: https://syzkaller.appspot.com/bug?extid=d6f9ff86c1d804ba2bc6 Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin --- fs/btrfs/extent-tree.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 0640ef59fe660..08ff10a81cb90 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -863,6 +863,11 @@ int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, err = -ENOENT; goto out; } else if (WARN_ON(ret)) { + btrfs_print_leaf(path->nodes[0]); + btrfs_err(fs_info, +"extent item not found for insert, bytenr %llu num_bytes %llu parent %llu root_objectid %llu owner %llu offset %llu", + bytenr, num_bytes, parent, root_objectid, owner, + offset); err = -EIO; goto out; }