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From: "Michael S. Tsirkin" <mst@redhat.com>
To: Gerd Hoffmann <kraxel@redhat.com>
Cc: "Gabriel L. Somlo" <somlo@cmu.edu>,
	qemu-devel@nongnu.org, "Gabriel L. Somlo" <gsomlo@gmail.com>,
	pbonzini@redhat.com, lersek@redhat.com
Subject: Re: [Qemu-devel] fw cfg files cross-version migration races
Date: Wed, 3 Jun 2015 18:03:05 +0200	[thread overview]
Message-ID: <20150603180200-mutt-send-email-mst@redhat.com> (raw)
In-Reply-To: <1433229074.1637.7.camel@nilsson.home.kraxel.org>

On Tue, Jun 02, 2015 at 09:11:14AM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > I guess the only reason this isn't a problem is that nobody currently
> > attempts to access fw_cfg after a migration ? :)
> 
> Accessing fw_cfg after migration is fine.  Problem is this ...
> 
>   (1) read directory
>   (2) migrate
>   (3) read file
> 
> ... in case the file ordering happens to be different on the destination
> host due to initialization order changes.
> 
> So, sorting entries (and the index assigned too) should fix this, right?
> That looks easiest to me.
> 
> cheers,
>   Gerd

Right. The only issue is we are introducing a breakage even if
there was otherwise no reason for it otherwise.
I'll let you make the decision.

-- 
MST

  parent reply	other threads:[~2015-06-03 16:03 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-01 14:10 [Qemu-devel] fw cfg files cross-version migration races Michael S. Tsirkin
2015-06-01 14:13 ` Daniel P. Berrange
2015-06-01 15:32   ` Gabriel L. Somlo
2015-06-01 15:44     ` Michael S. Tsirkin
2015-06-01 18:00       ` Gabriel L. Somlo
2015-06-01 20:31         ` Gabriel L. Somlo
2015-06-02  7:04           ` Laszlo Ersek
2015-06-02  7:11           ` Gerd Hoffmann
2015-06-03  8:31             ` Paolo Bonzini
2015-06-03 16:03             ` Michael S. Tsirkin [this message]
2015-06-05 16:05             ` Gabriel L. Somlo
2015-06-08  7:21               ` Gerd Hoffmann
2015-06-08  9:43                 ` Michael S. Tsirkin
2015-06-08 11:19                   ` Gerd Hoffmann
2015-06-08 11:44                     ` Paolo Bonzini
2015-06-08 12:23                       ` Gabriel L. Somlo
2015-06-08 12:28                         ` Paolo Bonzini
2015-06-08 12:33                         ` Gerd Hoffmann
2015-06-08 13:32                           ` Gabriel L. Somlo
2015-06-08 15:53                             ` Michael S. Tsirkin

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