From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pavel Emelyanov <xemul@parallels.com>
Subject: Re: [rfc 3/4] fs, eventfd: Add procfs fdinfo helper
Date: Thu, 17 May 2012 20:34:59 +0400
Message-ID: <4FB528B3.8000406@parallels.com>
References: <20120517160738.116113099@openvz.org> <20120517162534.755208902@openvz.org>
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Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	James Bottomley <jbottomley@parallels.com>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
To: Cyrill Gorcunov <gorcunov@openvz.org>
Return-path: <linux-kernel-owner@vger.kernel.org>
In-Reply-To: <20120517162534.755208902@openvz.org>
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List-Id: linux-fsdevel.vger.kernel.org

> +static void *seq_start(struct seq_file *m, loff_t *pos)
> +{
> +	struct proc_fdinfo_extra *extra = m->private;
> +	return *pos == 1 ? extra->fd_file : NULL;
> +}
> +
> +static void seq_stop(struct seq_file *m, void *v)
> +{
> +}
> +
> +static void *seq_next(struct seq_file *m, void *p, loff_t *pos)
> +{
> +	struct proc_fdinfo_extra *extra = m->private;
> +	return ++*pos == 1 ? extra->fd_file : NULL;
> +}
> +

<snip>

> +static const struct seq_operations eventfd_fdinfo_ops = {
> +	.start	= seq_start,
> +	.next	= seq_next,
> +	.stop	= seq_stop,
> +	.show	= seq_show,

I think, you can use the single_ part of the seq files engine.

> +};

Thanks,
Pavel