From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Monjalon <thomas@monjalon.net>
Subject: Re: [PATCH] bus/vdev: reduce scope of device list lock
Date: Tue, 22 May 2018 11:20:10 +0200
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References: <20180521161156.25724-1-thomas@monjalon.net>
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Cc: dev@dpdk.org, matan@mellanox.com, ferruh.yigit@intel.com
To: "Burakov, Anatoly" <anatoly.burakov@intel.com>
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22/05/2018 11:05, Burakov, Anatoly:
> On 21-May-18 5:11 PM, Thomas Monjalon wrote:
> > The lock vdev_device_list_lock was taken before calling
> > "remove" function for the device.
> > So it prevents to remove sub-devices (as in failsafe) inside
> > its own "remove" function, because of a deadlock.
> > 
> > The lock is now only protecting the device list inside
> > the bus driver.
> > 
> > Fixes: 35f462839b69 ("bus/vdev: add lock on device list")
> > 
> > Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> 
> Without that lock, all of this would be racy - find_dev would iterate a 
> tailq that might change under its feet, and tailq_remove may be called 
> with a pointer that has already been removed.
> 
> How about changing the lock to a recursive lock? Failsafe would be 
> removing devices from within the same thread, correct?

Yes it could work.
I will give it a try.