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From: Steven Rostedt <rostedt@goodmis.org>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: Bart Van Assche <bvanassche@acm.org>,
	axboe@kernel.dk, viro@zeniv.linux.org.uk,
	gregkh@linuxfoundation.org, mingo@redhat.com, jack@suse.cz,
	ming.lei@redhat.com, nstange@suse.de, akpm@linux-foundation.org,
	mhocko@suse.com, yukuai3@huawei.com, linux-block@vger.kernel.org,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 05/10] blktrace: upgrade warns to BUG_ON() on unexpected circmunstances
Date: Mon, 20 Apr 2020 19:20:09 -0400	[thread overview]
Message-ID: <20200420192009.073a1cec@oasis.local.home> (raw)
In-Reply-To: <20200419230730.GH11244@42.do-not-panic.com>

On Sun, 19 Apr 2020 23:07:30 +0000
Luis Chamberlain <mcgrof@kernel.org> wrote:

> On Sun, Apr 19, 2020 at 03:50:13PM -0700, Bart Van Assche wrote:
> > On 4/19/20 12:45 PM, Luis Chamberlain wrote:  
> > > @@ -498,10 +498,7 @@ static struct dentry *blk_trace_debugfs_dir(struct blk_user_trace_setup *buts,
> > >   	struct dentry *dir = NULL;
> > >   	/* This can only happen if we have a bug on our lower layers */
> > > -	if (!q->kobj.parent) {
> > > -		pr_warn("%s: request_queue parent is gone\n", buts->name);
> > > -		return NULL;
> > > -	}
> > > +	BUG_ON(!q->kobj.parent);  
> > 
> > Does the following quote from Linus also apply to this patch: "there is NO
> > F*CKING EXCUSE to knowingly kill the kernel." See also
> > https://lkml.org/lkml/2016/10/4/1.  
> 
> We can use WARN_ON() and keep the return NULL, sure.
> 

Yes please. This is definitely not something that should kill the system.

-- Steve


  reply	other threads:[~2020-04-20 23:20 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-19 19:45 [PATCH v2 00/10] block: fix blktrace debugfs use after free Luis Chamberlain
2020-04-19 19:45 ` [PATCH v2 01/10] block: move main block debugfs initialization to its own file Luis Chamberlain
2020-04-19 21:06   ` Bart Van Assche
2020-04-19 19:45 ` [PATCH v2 02/10] blktrace: move blktrace debugfs creation to helper function Luis Chamberlain
2020-04-19 21:11   ` Bart Van Assche
2020-04-22  7:12   ` Christoph Hellwig
2020-04-19 19:45 ` [PATCH v2 03/10] blktrace: fix debugfs use after free Luis Chamberlain
2020-04-19 21:55   ` Bart Van Assche
2020-04-20  0:04     ` Luis Chamberlain
2020-04-20  0:38       ` Bart Van Assche
2020-04-20 18:46         ` Luis Chamberlain
2020-04-20 20:16   ` Greg KH
2020-04-20 20:41     ` Luis Chamberlain
2020-04-21  7:00       ` Greg KH
2020-04-22  7:28         ` Luis Chamberlain
2020-04-22  9:43           ` Ming Lei
2020-04-22 10:31             ` Luis Chamberlain
2020-04-24 23:47             ` Luis Chamberlain
2020-04-22  7:29       ` Christoph Hellwig
2020-04-22  7:34         ` Luis Chamberlain
2020-04-22  7:27   ` Christoph Hellwig
2020-04-22  7:48     ` Luis Chamberlain
2020-04-22  8:10       ` Christoph Hellwig
2020-04-22  8:26         ` Luis Chamberlain
2020-04-19 19:45 ` [PATCH v2 04/10] block: revert back to synchronous request_queue removal Luis Chamberlain
2020-04-19 22:23   ` Bart Van Assche
2020-04-20 18:59     ` Luis Chamberlain
2020-04-20 21:11       ` Bart Van Assche
2020-04-20 21:51         ` Luis Chamberlain
2020-04-19 19:45 ` [PATCH v2 05/10] blktrace: upgrade warns to BUG_ON() on unexpected circmunstances Luis Chamberlain
2020-04-19 22:50   ` Bart Van Assche
2020-04-19 23:07     ` Luis Chamberlain
2020-04-20 23:20       ` Steven Rostedt [this message]
2020-04-19 19:45 ` [PATCH v2 06/10] blk-debugfs: upgrade warns to BUG_ON() if directory is already found Luis Chamberlain
2020-04-20 11:36   ` Greg KH
2020-04-25 11:43   ` [blk] 90d38c0e30: kernel_BUG_at_block/blk-debugfs.c kernel test robot
2020-04-19 19:45 ` [PATCH v2 07/10] blktrace: move debugfs file creation to its own function Luis Chamberlain
2020-04-19 22:55   ` Bart Van Assche
2020-04-20 11:37     ` Greg KH
2020-04-19 19:45 ` [PATCH v2 08/10] blktrace: add checks for created debugfs files on setup Luis Chamberlain
2020-04-19 22:57   ` Bart Van Assche
2020-04-19 23:05     ` Luis Chamberlain
2020-04-19 23:17       ` Bart Van Assche
2020-04-20 11:40         ` Greg KH
2020-04-20 18:44           ` Luis Chamberlain
2020-04-20 20:11             ` Greg KH
2020-04-20 20:20               ` Luis Chamberlain
2020-04-21  6:55                 ` Greg KH
2020-04-20 11:39   ` Greg KH
2020-04-19 19:45 ` [PATCH v2 09/10] block: panic if block debugfs dir is not created Luis Chamberlain
2020-04-19 23:08   ` Bart Van Assche
2020-04-20 11:38   ` Greg KH
2020-04-19 19:45 ` [PATCH v2 10/10] block: put_device() if device_add() fails Luis Chamberlain
2020-04-19 23:40   ` Bart Van Assche
2020-04-24 22:32     ` Luis Chamberlain
2020-04-25  1:58       ` Bart Van Assche
2020-04-25  2:12         ` Luis Chamberlain
2020-04-19 19:48 ` [PATCH v2 00/10] block: fix blktrace debugfs use after free Luis Chamberlain

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