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Date: Wed, 17 Jan 2024 13:58:24 +0100
From: Jan Kara <jack@suse.cz>
To: yangerkun <yangerkun@huawei.com>
Cc: tytso@mit.edu, adilger.kernel@dilger.ca, jack@suse.cz,
	linux-ext4@vger.kernel.org, yangerkun@huaweicloud.com
Subject: Re: [PATCH 2/2] ext4: distinguish different error in
 ext4_mb_seq_groups_show
Message-ID: <20240117125824.paah5ncjhmoyzwom@quack3>
References: <20240117115223.80253-1-yangerkun@huawei.com>
 <20240117115223.80253-2-yangerkun@huawei.com>
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In-Reply-To: <20240117115223.80253-2-yangerkun@huawei.com>

On Wed 17-01-24 19:52:23, yangerkun wrote:
> While cat mb_groups for a mounted ext4 image which has some corrupted
> group, the string return to userspace was just "I/O error" which confuse
> me a lot. Use ext4_decode_error to help distinguish different error.
> 
> Signed-off-by: yangerkun <yangerkun@huawei.com>

I guess this is an improvement :). Feel free to add:

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

								Honza

> ---
>  fs/ext4/mballoc.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index 139f232bdbb5..77d6113e2822 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2991,6 +2991,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
>  	struct super_block *sb = pde_data(file_inode(seq->file));
>  	ext4_group_t group = (ext4_group_t) ((unsigned long) v);
>  	int i, err;
> +	char nbuf[16];
>  	struct ext4_buddy e4b;
>  	struct ext4_group_info *grinfo;
>  	unsigned char blocksize_bits = min_t(unsigned char,
> @@ -3017,7 +3018,7 @@ static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
>  	if (unlikely(EXT4_MB_GRP_NEED_INIT(grinfo))) {
>  		err = ext4_mb_load_buddy(sb, group, &e4b);
>  		if (err) {
> -			seq_printf(seq, "#%-5u: I/O error\n", group);
> +			seq_printf(seq, "#%-5u: %s\n", group, ext4_decode_error(NULL, err, nbuf));
>  			return 0;
>  		}
>  		ext4_mb_unload_buddy(&e4b);
> -- 
> 2.39.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR