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Date:   Sun, 21 Feb 2021 16:52:33 +0000
From:   Al Viro <viro@zeniv.linux.org.uk>
To:     Luo Longjun <luolongjun@huawei.com>
Cc:     jlayton@kernel.org, bfields@fieldses.org,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        sangyan@huawei.com, luchunhua@huawei.com
Subject: Re: [PATCH] fs/locks: print full locks information
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References: <20210220063250.742164-1-luolongjun@huawei.com>
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On Sat, Feb 20, 2021 at 01:32:50AM -0500, Luo Longjun wrote:
>  
> @@ -2844,7 +2845,13 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl,
>  	if (fl->fl_file != NULL)
>  		inode = locks_inode(fl->fl_file);
>  
> -	seq_printf(f, "%lld:%s ", id, pfx);
> +	seq_printf(f, "%lld: ", id);
> +	for (i = 1; i < repeat; i++)
> +		seq_puts(f, " ");
> +
> +	if (repeat)
> +		seq_printf(f, "%s", pfx);

RTFCStandard(printf, %*s), please

> +static int __locks_show(struct seq_file *f, struct file_lock *fl, int level)
> +{
> +	struct locks_iterator *iter = f->private;
> +	struct file_lock *bfl;
> +
> +	lock_get_status(f, fl, iter->li_pos, "-> ", level);
> +
> +	list_for_each_entry(bfl, &fl->fl_blocked_requests, fl_blocked_member)
> +		__locks_show(f, bfl, level + 1);

Er...  What's the maximal depth, again?  Kernel stack is very much finite...