Date: Mon, 18 Aug 2014 12:18:36 -0400
To: kbuild test robot <fengguang.wu@intel.com>
Cc: Trond Myklebust <trond.myklebust@primarydata.com>,
        "J. Bruce Fields" <bfields@redhat.com>, kbuild-all@01.org,
        linux-nfs@vger.kernel.org
Subject: Re: [nfsd:nfsd-next 5/23] net/sunrpc/svc_xprt.c:794:20: error:
 'current_task' undeclared
Message-ID: <20140818161836.GA32603@fieldses.org>
References: <53f0db34.mtq2J6NaXWKpR15G%fengguang.wu@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
In-Reply-To: <53f0db34.mtq2J6NaXWKpR15G%fengguang.wu@intel.com>
From: "J. Bruce Fields" <bfields@fieldses.org>
Sender: linux-nfs-owner@vger.kernel.org

On Mon, Aug 18, 2014 at 12:41:24AM +0800, kbuild test robot wrote:
> tree:   git://linux-nfs.org/~bfields/linux.git nfsd-next
> head:   da8b8f7602ed3b8105c6247a2844455fec72caaa
> commit: 983c684466e02b21f83c025ea539deee6c0aeac0 [5/23] SUNRPC: get rid of the request wait queue
> config: make ARCH=xtensa allyesconfig
> 
> All error/warnings:
> 
>    net/sunrpc/svc_xprt.c: In function 'svc_recv':
> >> net/sunrpc/svc_xprt.c:794:20: error: 'current_task' undeclared (first use in this function)
>       rqstp->rq_task = current_task;
>                        ^
>    net/sunrpc/svc_xprt.c:794:20: note: each undeclared identifier is reported only once for each function it appears in
> 
> vim +/current_task +794 net/sunrpc/svc_xprt.c
> 
>    788			printk(KERN_ERR
>    789				"svc_recv: service %p, transport not NULL!\n",
>    790				 rqstp);
>    791	
>    792		/* Make sure the task pointer is set! */
>    793		if (WARN_ON_ONCE(!rqstp->rq_task))
>  > 794			rqstp->rq_task = current_task;

I appreciate the effort to fail gracefully here, but maybe this would be
a case for simple BUG_ON()?

I don't think there are normally any important locks held here, and I
can't see any other reason why killing a server thread would bring a box
down.

And the first developer to forget to set rq_task on a newly created
server will get an immediate bug, so this should be obvious enough.
Unless there's fear of a race between starting the thread and setting
rq_task?

--b.

>    795	
>    796		err = svc_alloc_arg(rqstp);
>    797		if (err)
> 
> ---
> 0-DAY kernel build testing backend              Open Source Technology Center
> http://lists.01.org/mailman/listinfo/kbuild                 Intel Corporation