Re: Fix soft lockup with iSeries viocd driver

From: Jens Axboe
Date: Wed Feb 28 2007 - 07:17:44 EST


On Wed, Feb 28 2007, Tony Breeds wrote:
> On Tue, Feb 27, 2007 at 03:33:34PM +0100, Jens Axboe wrote:
>
> > It looks ok (better than end_request()), though it would still be nice
> > to properly end requests. See the recent thread on the lguest block
> > driver.
>
> Hi Jens,
> I read through the lguest thread and came up with the patch
> below, I hope I understood correctly. We still need to do the check to
> make sure we ask for at least one sector to be processed in
> end_that_request_first(), as the request that triggers the lockup here
> (an sg_io ioctl in this case), has both req->hard_nr_sectors and
> req->hard_cur_sectors = 0.

Yep that looks better.

> From: Tony Breeds <tony@xxxxxxxxxxxxxxxxxx>
>
> Fix soft lockup with iSeries viocd driver, caused by eventually calling
> end_that_request_first() with nr_bytes 0.
>
> The lockup is triggered by hald, interrogating the device.
>
> Signed-off-by: Tony Breeds <tony@xxxxxxxxxxxxxxxxxx>

Signed-off-by: Jens Axboe <jens.axboe@xxxxxxxxxx>

--
Jens Axboe

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