Re: [PATCH] pci/switchtec: fix stream_open.cocci warnings (fwd)

Bjorn Helgaas
2019-06-19T20:19:05Z

On Wed, Jun 19, 2019 at 04:27:52PM +0000, Kirill Smelkov wrote:
> Hi Julia, everyone.
>
> On Wed, Jun 19, 2019 at 12:28:47PM +0200, Julia Lawall wrote:
> > Hi,
> >
> > Can you forward this patch to the people below if you think it is
> > appropriate?
>
> Yes, this patch is appropriate. It was actually part of
> git.kernel.org/linus/c5bf68fe0c86 . It should be safe, (and desirable as
> it removes a chance for deadlock) to apply it.
>
> Sebastian, Kurt, Logan, Bjorn, please consider picking it up.

I don't get it. This appeared in v5.2-rc1 as c5bf68fe0c86 ("*: convert
stream-like files from nonseekable_open -> stream_open"), so it looks like
this is already done. What would you like me to do with it?

> > Could I tell the kbuild people to add you to the CC list for
> > this semantic patch?
>
> Yes, sure. Please feel free to add me to CC list for stream_open.cocci
> related patches.
>
> Kirill
>
>
> > thanks,
> > julia
> >
> > ---------- Forwarded message ----------
> > Date: Wed, 19 Jun 2019 18:23:18 +0800
> > From: kbuild test robot <lkp@intel.com>
> > To: kbuild@01.org
> > Cc: Julia Lawall <julia.lawall@lip6.fr>
> > Subject: [PATCH] pci/switchtec: fix stream_open.cocci warnings
> >
> > CC: kbuild-all@01.org
> > TO: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > CC: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
> > CC: Logan Gunthorpe <logang@deltatee.com>
> > CC: Bjorn Helgaas <helgaas@kernel.org>
> > CC: linux-pci@vger.kernel.org
> > CC: linux-kernel@vger.kernel.org
> >
> > From: kbuild test robot <lkp@intel.com>
> >
> > drivers/pci/switch/switchtec.c:395:1-17: ERROR: switchtec_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix.
> >
> > Generated by: scripts/coccinelle/api/stream_open.cocci
> >
> > Fixes: a3a1e895d4fa ("pci/switchtec: Don't use completion's wait queue")
> > Signed-off-by: kbuild test robot <lkp@intel.com>
> > ---
> >
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-5.0.y-rt-rebase
> > head: 31cc76d5590f5e60c2f26f029e40bc7d0441d93f
> > commit: a3a1e895d4fa0508e11ac9107ace883a5b2a4d3b [171/305] pci/switchtec: Don't use completion's wait queue
> > :::::: branch date: 6 days ago
> > :::::: commit date: 6 days ago
> >
> > Please take the patch only if it's a positive warning. Thanks!
> >
> > switchtec.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > --- a/drivers/pci/switch/switchtec.c
> > +++ b/drivers/pci/switch/switchtec.c
> > @@ -392,7 +392,7 @@ static int switchtec_dev_open(struct ino
> > return PTR_ERR(stuser);
> >
> > filp->private_data = stuser;
> > - nonseekable_open(inode, filp);
> > + stream_open(inode, filp);
> >
> > dev_dbg(&stdev->dev, "%s: %p\n", __func__, stuser);
> >