linux-kernel - Re: [PATCH 2/4] ext4: do not trim the group with corrupted block bitmap

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Date: Mon, 18 Dec 2023 16:02:53 +0100
From: Jan Kara <jack@...e.cz>
To: Baokun Li <libaokun1@...wei.com>
Cc: linux-ext4@...r.kernel.org, tytso@....edu, adilger.kernel@...ger.ca,
	jack@...e.cz, ritesh.list@...il.com, linux-kernel@...r.kernel.org,
	yi.zhang@...wei.com, yangerkun@...wei.com, yukuai3@...wei.com
Subject: Re: [PATCH 2/4] ext4: do not trim the group with corrupted block
 bitmap

On Mon 18-12-23 22:18:12, Baokun Li wrote:
> Otherwise operating on an incorrupted block bitmap can lead to all sorts
> of unknown problems.
> 
> Signed-off-by: Baokun Li <libaokun1@...wei.com>

I agree this is a safer option. Feel free to add:

Reviewed-by: Jan Kara <jack@...e.cz>

								Honza

> ---
>  fs/ext4/mballoc.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index d72b5e3c92ec..a95fa6e2b0f9 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -6757,6 +6757,9 @@ __releases(ext4_group_lock_ptr(sb, e4b->bd_group))
>  	bool set_trimmed = false;
>  	void *bitmap;
>  
> +	if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)))
> +		return 0;
> +
>  	bitmap = e4b->bd_bitmap;
>  	if (start == 0 && max >= ext4_last_grp_cluster(sb, e4b->bd_group))
>  		set_trimmed = true;
> -- 
> 2.31.1
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR