Re: [2.6.24 REGRESSION] BUG: Soft lockup - with VFS

From: FUJITA Tomonori
Date: Mon Feb 11 2008 - 20:55:18 EST


On Fri, 8 Feb 2008 23:46:19 -0800
Pete Zaitcev <zaitcev@xxxxxxxxxx> wrote:

> On Tue, 5 Feb 2008 14:05:06 -0800, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> > > > http://students.zipernowsky.hu/~oliverp/kernel/regression_2624/
>
> > I think ub.c is basically abandoned in favour of usb-storage.
> > If so, perhaps we should remove or disble ub.c?
>
> Looks like it's just Tomo or Jens made a mistake when converting to
> the new s/g API. Nothing to be too concerned about. I know I should've
> reviewed their patch closer, but it seemed too simple...

I guess I can put the blame for this on Jens' commit (45711f1a) ;)

On a serious note, it seems that two scatter lists per request leaded
to this bug. Can the scatter list in struct ub_request be removed?

Thanks,

> -- Pete
>
> Fix up the conversion to sg_init_table().
>
> Signed-off-by: Pete Zaitcev <zaitcev@xxxxxxxxxx>
>
> --- a/drivers/block/ub.c
> +++ b/drivers/block/ub.c
> @@ -657,7 +657,6 @@ static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
> if ((cmd = ub_get_cmd(lun)) == NULL)
> return -1;
> memset(cmd, 0, sizeof(struct ub_scsi_cmd));
> - sg_init_table(cmd->sgv, UB_MAX_REQ_SG);
>
> blkdev_dequeue_request(rq);
>
> @@ -668,6 +667,7 @@ static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
> /*
> * get scatterlist from block layer
> */
> + sg_init_table(&urq->sgv[0], UB_MAX_REQ_SG);
> n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
> if (n_elem < 0) {
> /* Impossible, because blk_rq_map_sg should not hit ENOMEM. */
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/