linux-kernel - Re: [BUG] act_ife: sleeping functions called in atomic context

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Message-ID: <CAM_iQpUV1OaHCNkXWwGpkAPkSMzk5Rdw0ptijt4QFk9xa0FkxQ@mail.gmail.com>
Date:	Fri, 17 Jun 2016 10:16:44 -0700
From:	Cong Wang <xiyou.wangcong@...il.com>
To:	Alexey Khoroshilov <khoroshilov@...ras.ru>
Cc:	Jamal Hadi Salim <jhs@...atatu.com>,
	"David S. Miller" <davem@...emloft.net>,
	Linux Kernel Network Developers <netdev@...r.kernel.org>,
	LKML <linux-kernel@...r.kernel.org>, ldv-project@...uxtesting.org
Subject: Re: [BUG] act_ife: sleeping functions called in atomic context

On Fri, Jun 17, 2016 at 4:05 AM, Alexey Khoroshilov
<khoroshilov@...ras.ru> wrote:
> On 17.06.2016 08:38, Cong Wang wrote:
>> On Thu, Jun 16, 2016 at 7:14 PM, Cong Wang <xiyou.wangcong@...il.com> wrote:
>>>
>>> I think we can just remove that tcf_lock, I am testing a patch now.
>>
>> Please try the attached patch, I will do more tests tomorrow.
>>
>> Thanks!
>>
>
> Looks good with two notes:
> 1. add_metainfo() still contains
> ret = ops->alloc(mi, metaval);
> that allocates memory with GFP_KERNEL.
> So, I would add gfpflag argument to alloc() operation.

I thought about this too, but we just allocate 32+ bytes here,
not sure if it is really worth to pass a gfp flag.

>
> 2. It makes sense to mention ife_mod_lock in the comment before
> add_metainfo(), because ife_mod_lock is the reason to use GFP_ATOMIC there.

Don't worry, it is in a separated patch, I will explain this
in the changelog. (I sent a combined patch just for review/tests.)

Thanks!