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

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

在 2024/10/4 18:53, Johannes Thumshirn 写道:
> From: Johannes Thumshirn <johannes.thumshirn@wdc.com>
>
> Curretnly 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@suse.com>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
> ---
>   fs/btrfs/inode.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
> index 103ec917ca9d..19ba101dc09c 100644
> --- a/fs/btrfs/inode.c
> +++ b/fs/btrfs/inode.c
> @@ -3088,7 +3088,10 @@ 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));
> +		if (list_empty(&ordered_extent->list)) {
> +			ASSERT(list_empty(&ordered_extent->list));

Will the ASSERT() really get triggered? We just checked the same
list_empty() one line before.

I guess you mean ASSERT(!list_empty()) instead?

Otherwise changing it to ASSERT() and btrfs_abort_transaction() looks
good to me.

Thanks,
Qu

> +			btrfs_abort_transaction(trans, -EINVAL);
> +		}
>
>   		btrfs_inode_safe_disk_i_size_write(inode, 0);
>   		ret = btrfs_update_inode_fallback(trans, inode);