Re: [Xen-devel] netback Oops then xenwatch stuck in D state

[David Vrabel <david.vrabel@xxxxxxxxxx>]

On 14/02/13 11:48, Jan Beulich wrote:
>>>> On 14.02.13 at 12:20, Wei Liu <wei.liu2@xxxxxxxxxx> wrote:
> 
>> If this is a bug, and, if my previous patch fixes Christopher's OOPS, he
>> will hit this bug soon when shutting down DomU.
> 
> I don't think this patch will fix his problems, which - as described
> yesterday - I'm relatively certain result from the harsh action
> netbk_fatal_tx_err() does.

I can't see anything broken in netbk_fatal_tx_err().

However, a call to netbk_fatal_tx_err() may result in the vif's ref
count going to 1 which means a simutaneous attempt to shutdown the vif
will free the net device.

Netback thread              Xenwatch thread

netbk_fatal_tx_err()        netback_remove()
                              xenvif_disconnect()
                                ...
                                free_netdev()
netbk_tx_err() Oops!

David

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