Messages in this thread | | | Subject | Re: [PATCH v3 part1 1/4] sg_io: pass request_queue to blk_verify_command | From | James Bottomley <> | Date | Sat, 25 May 2013 00:14:07 -0400 |
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On Fri, 2013-05-24 at 10:32 +0200, Paolo Bonzini wrote: > Il 24/05/2013 10:03, James Bottomley ha scritto: > >>>>> > >>> Does anyone in the real world actually care about this bug? > >>>> > >> > >>>> > >> Yes, or I would move on and not waste so much time on this. > >>> > > > >>> > > Fine, so produce a simple fix for this bug which we can discuss that's > >>> > > not tied to this feature. > >> > > >> > Honestly, I have no idea how this is even possible. > > Really? It looks to me like a simple block on the commands for disk > > devices in the opcode switch would do it (with a corresponding change to > > sg.c:sg_allow_access). > > Which switch? What I can do is something like this in blk_verify_command:
not in blk_verify_command: outside of it, in the three places it's used.
> if (q->sgio_type == TYPE_ROM) > return 0; > if (rq->cmd[0] == 0xA4) > return -EPERM; > if (!is_write && > (req->cmd[0] == ... || rq->cmd[0] == ...)) > return -EPERM; > > But then the particular patch you're replying to is still necessary, > and you're slowing down blk_verify_command.
It's a set if if switches in non performance critical code.
> It may be fine for stable > and -rc, but IMHO it calls for a better implementation in 3.11.
What goes into stable should be what goes into the real kernel and it helps separate the bug fix from feature argument.
James
> (Besides, I did it like this because it is what Tejun suggested).
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