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Date: Tue, 13 Feb 2024 11:21:39 +0100
From: Jan Kara <jack@suse.cz>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Jan Kara <jack@suse.com>, Arnd Bergmann <arnd@arndb.de>,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] quota: avoid printing an uninitialized blk number
Message-ID: <20240213102139.gnfh5sq24rwu7wnp@quack3>
References: <20240213101733.461544-1-arnd@kernel.org>
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On Tue 13-02-24 11:17:28, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> The error path of find_tree_dqentry() now prints a variable that is
> never initialized:
> 
> fs/quota/quota_tree.c:674:8: error: variable 'blk' is uninitialized when used here [-Werror,-Wuninitialized]
>                             blk);
>                             ^~~
> include/linux/quotaops.h:34:41: note: expanded from macro 'quota_error'
>         __quota_error((sb), __func__, fmt , ## args)
>                                                ^~~~
> 
> Move the calculation of the block number slightly up to make it
> show a sensible number.
> 
> Fixes: 223bfb57631b ("quota: Detect loops in quota tree")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Arnd, this should be fixed in my tree as of yesterday and I can see that
you've even based your patch on a fixed kernel :)

								Honza

> ---
>  fs/quota/quota_tree.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
> index afceef3ddfaa..05ae39f9b1ac 100644
> --- a/fs/quota/quota_tree.c
> +++ b/fs/quota/quota_tree.c
> @@ -669,13 +669,13 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
>  	if (!buf)
>  		return -ENOMEM;
>  	ret = read_blk(info, blks[depth], buf);
> +	blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
>  	if (ret < 0) {
>  		quota_error(dquot->dq_sb, "Can't read quota tree block %u",
>  			    blks[depth]);
>  		goto out_buf;
>  	}
>  	ret = 0;
> -	blk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
>  	if (!blk)	/* No reference? */
>  		goto out_buf;
>  	ret = do_check_range(dquot->dq_sb, "block", blk, QT_TREEOFF,
> -- 
> 2.39.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR