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From: Keith Busch <keith.busch@intel.com>
To: Lukas Wunner <lukas@wunner.de>
Cc: Linux PCI <linux-pci@vger.kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH] pci/sriov: Hold rescan lock while enumerating
Date: Thu, 9 Aug 2018 12:05:34 -0600	[thread overview]
Message-ID: <20180809180534.GA18816@localhost.localdomain> (raw)
In-Reply-To: <20180809175819.42j6laq5gxtpnlxy@wunner.de>

On Thu, Aug 09, 2018 at 07:58:19PM +0200, Lukas Wunner wrote:
> On Thu, Aug 09, 2018 at 10:33:56AM -0600, Keith Busch wrote:
> > --- a/drivers/pci/pci-sysfs.c
> > +++ b/drivers/pci/pci-sysfs.c
> > @@ -591,6 +591,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,
> >  	if (num_vfs > pci_sriov_get_totalvfs(pdev))
> >  		return -ERANGE;
> >  
> > +	pci_lock_rescan_remove();
> >  	device_lock(&pdev->dev);
> 
> Doesn't this obviate the need to hold the device_lock()?  What could
> otherwise run concurrently that doesn't hold pci_lock_rescan_remove()
> and would cause a race condition?

The device_lock is still needed to protect against concurrent
pci_reset_function.

  reply	other threads:[~2018-08-09 20:30 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-09 16:33 [PATCH] pci/sriov: Hold rescan lock while enumerating Keith Busch
2018-08-09 17:58 ` Lukas Wunner
2018-08-09 18:05   ` Keith Busch [this message]
2018-09-05 20:58 ` Bjorn Helgaas
2018-09-05 21:12   ` Keith Busch
2018-09-05 22:13     ` Bjorn Helgaas

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