linux-kernel - Re: [PATCH 3/5] cgroup: fix mount failure in a corner case

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 20 Jun 2014 15:10:25 -0400
From:	Tejun Heo <tj@...nel.org>
To:	Li Zefan <lizefan@...wei.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Cgroups <cgroups@...r.kernel.org>
Subject: Re: [PATCH 3/5] cgroup: fix mount failure in a corner case

On Thu, Jun 12, 2014 at 02:32:13PM +0800, Li Zefan wrote:
> @@ -1677,6 +1679,22 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
>  		goto out_unlock;
>  	}
>  
> +	/*
> +	 * If some subsystems have been bound to existing cgroup hierarchies,
> +	 * but those hierachies are being destroyed, let's wait a little bit
> +	 * and retry.
> +	 */
> +	for_each_subsys(ss, i) {
> +		if (!(opts.subsys_mask & (1 << i)))
> +			continue;
> +		if (!percpu_ref_alive(&ss->root->cgrp.self.refcnt)) {

Can't we just do tryget_live() instead and then put before retrying?
It's not exactly a hot path and the operations are dirt cheap anyway.

Thanks.

-- 
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/