From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ian Jackson <Ian.Jackson@eu.citrix.com>
Subject: Re: [PATCH v2] xenconsole: Ensure exclusive access to
	console using locks
Date: Fri, 24 Jul 2015 16:07:14 +0100
Message-ID: <21938.21666.285588.16673@mariner.uk.xensource.com>
References: <20150724134222.GF25338@nodbug.lucina.net>
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To: Martin Lucina <martin@lucina.net>
Cc: xen-devel@lists.xenproject.org, Wei Liu <wei.liu2@citrix.com>, Ian Campbell <ian.campbell@citrix.com>, Stefano Stabellini <stefano.stabellini@eu.citrix.com>
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Martin Lucina writes ("[PATCH v2] xenconsole: Ensure exclusive access to console using locks"):
> If more than one instance of xenconsole is run against the same DOMID
> then each instance will only get some data. This change ensures
> exclusive access to the console by obtaining an exclusive lock on
> <XEN_LOCK_DIR>/xenconsole.<DOMID>.
...
> +static void console_unlock(void)
> +{
> +	if (lockfile[0])
> +		unlink(lockfile);
> +	if (lockfd != -1)
> +		close(lockfd);
> +}

If called when unlocked this could unlink the lockfile anyway.

Ian.