Re: [PATCH v3] btrfs: don't BUG_ON() NOCOW ordered-extents with checksum list

[Filipe Manana]

On Fri, Oct 4, 2024 at 2:21 PM Johannes Thumshirn <jth@xxxxxxxxxx> wrote:
>
> From: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
>
> Currently we BUG_ON() in btrfs_finish_one_ordered() if we finishing an
> ordered-extent that is flagged as NOCOW, but it's checsum list is non-empty.
>
> This is clearly a logic error which we can recover from by aborting the
> transaction.
>
> For developer builds which enable CONFIG_BTRFS_ASSERT, also ASSERT() that the
> list is empty.
>
> Suggested-by: Filipe Manana <fdmanana@xxxxxxxx>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
> Reviewed-by: Qu Wenruo <wqu@xxxxxxxx>

Reviewed-by: Filipe Manana <fdmanana@xxxxxxxx>

Looks good, thanks.

> ---
> Changes to v2:
> * Move ASSERT() out of if () block (Filipe)
> * goto 'out' after aborting the transaction (Filipe)
>
> Changes to v1:
> * Fixup if () and ASSERT() (Qu)
> * Fix spelling of 'Currently'
> ---
>  fs/btrfs/inode.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 103ec917ca9d..ef82579dfe09 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -3088,7 +3088,12 @@ int btrfs_finish_one_ordered(struct btrfs_ordered_extent *ordered_extent)
>
>         if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
>                 /* Logic error */
> -               BUG_ON(!list_empty(&ordered_extent->list));
> +               ASSERT(list_empty(&ordered_extent->list));
> +               if (!list_empty(&ordered_extent->list)) {
> +                       ret = -EINVAL;
> +                       btrfs_abort_transaction(trans, ret);
> +                       goto out;
> +               }
>
>                 btrfs_inode_safe_disk_i_size_write(inode, 0);
>                 ret = btrfs_update_inode_fallback(trans, inode);
> --
> 2.43.0
>
>