Re: [PATCH 2/2] ext2: dump current reservation window info before BUG

From: Jan Kara
Date: Mon Aug 14 2023 - 09:09:15 EST


On Fri 11-08-23 11:38:57, Ye Bin wrote:
> There's report BUG in 'ext2_try_to_allocate_with_rsv()', although there's
> now dump of all reservation windows information. But there's unknown which
> window is being processed.So this is not helpful for locating the issue.
> To better analyze the problem, dump the information about reservation window
> that is being processed.
>
> Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
> ---
> fs/ext2/balloc.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
> index 039f655febfd..0132b8af546e 100644
> --- a/fs/ext2/balloc.c
> +++ b/fs/ext2/balloc.c
> @@ -1131,6 +1131,11 @@ ext2_try_to_allocate_with_rsv(struct super_block *sb, unsigned int group,
>
> if ((my_rsv->rsv_start > group_last_block) ||
> (my_rsv->rsv_end < group_first_block)) {
> + ext2_error(sb, __func__,
> + "Out of group %u range goal %d fsb[%lu,%lu] rsv[%lu, %lu]",
^^^ "Reservation out of group ...."

> + group, grp_goal, group_first_block,
> + group_last_block, my_rsv->rsv_start,
> + my_rsv->rsv_end);
> rsv_window_dump(&EXT2_SB(sb)->s_rsv_window_root, 1);
> BUG();
> }

And we could just bail with error instead of BUG here when we are already
changing the code...

Honza
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR