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Date:   Mon, 14 Aug 2023 15:08:30 +0200
From:   Jan Kara <jack@suse.cz>
To:     Ye Bin <yebin10@huawei.com>
Cc:     jack@suse.cz, linux-ext4@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] ext2: dump current reservation window info before BUG
Message-ID: <20230814130830.kizeni4hk5vjtqkm@quack3>
References: <20230811033857.1800578-1-yebin10@huawei.com>
 <20230811033857.1800578-3-yebin10@huawei.com>
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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@huawei.com>
> ---
>  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@suse.com>
SUSE Labs, CR