Re: [PATCH] btrfs: tree-checker: add type and sequence check for inline backrefs

[Josef Bacik <josef@toxicpanda.com>]

On Tue, Oct 24, 2023 at 12:41:11PM +1030, Qu Wenruo wrote:
> [BUG]
> There is a bug report that ntfs2btrfs had a bug that it can lead to
> transaction abort and the filesystem flips to read-only.
> 
> [CAUSE]
> For inline backref items, kernel has a strict requirement for their
> ordered, they must follow the following rules:
> 
> - All btrfs_extent_inline_ref::type should be in an ascending order
> 
> - Within the same type, the items should follow a descending order by
>   their sequence number
> 
>   For EXTENT_DATA_REF type, the sequence number is result from
>   hash_extent_data_ref().
>   For other types, their sequence numbers are
>   btrfs_extent_inline_ref::offset.
> 
> Thus if there is any code not following above rules, the resulted
> inline backrefs can prevent the kernel to locate the needed inline
> backref and lead to transaction abort.
> 
> [FIX]
> Ntrfs2btrfs has already fixed the problem, and btrfs-progs has added the
> ability to detect such problems.
> 
> For kernel, let's be more noisy and be more specific about the order, so
> that the next time kernel hits such problem we would reject it in the
> first place, without leading to transaction abort.
> 
> Link: https://github.com/kdave/btrfs-progs/pull/622
> Signed-off-by: Qu Wenruo <wqu@suse.com>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Does fsck catch this?  If not can you update it so it does?  Thanks,

Josef