Re: Bug of dm-crypt?

Milan Broz
2009-02-27T08:41:22Z

Herbert Xu wrote:
> On Fri, Feb 27, 2009 at 01:31:56PM +0800, Huang Ying wrote:
>> I had ever heard from you that the only thing guaranteed in the
>> completion function of async ablkcipher cryption is the req->data has
>> the value you set before. The request pointer itself may be changed. But
>> in dm-crypt, I found they rely on request pointer in completion
>> function: kcryptd_async_done. This makes my AES-NI cryptd usage panic.
>>
>> Do you think that is a bug?
>
> Absolutely.
>
> It should use cc->req instead.

ok, I'll check it and try to fix that.

Can you send me backtrace from that panic?

What's wrong in async callback now - mempool_free using async_req directly?

(Btw in some previous discussuion I asked if cryptd can be used
for some kind of parallel speedup for dm-crypt in async mode and response
was that cryptd "is only meant to be a demo showing how an async
implementation should be written".

So this changed to real working thread for AES-NI?)

Milan
--
mbroz@redhat.com