Re: IDE crash...

[Jens Axboe <jens.axboe@oracle.com>]

On Tue, Oct 23 2007, FUJITA Tomonori wrote:
> On Tue, 23 Oct 2007 12:58:11 +0200
> Jens Axboe <jens.axboe@oracle.com> wrote:
> 
> > On Tue, Oct 23 2007, Jens Axboe wrote:
> > > On Tue, Oct 23 2007, FUJITA Tomonori wrote:
> > > > On Tue, 23 Oct 2007 00:43:21 -0700 (PDT)
> > > > David Miller <davem@davemloft.net> wrote:
> > > > 
> > > > > From: Jens Axboe <jens.axboe@oracle.com>
> > > > > Date: Tue, 23 Oct 2007 09:23:59 +0200
> > > > > 
> > > > > > On Tue, Oct 23 2007, David Miller wrote:
> > > > > > > From: Jens Axboe <jens.axboe@oracle.com>
> > > > > > > Date: Tue, 23 Oct 2007 09:09:33 +0200
> > > > > > > 
> > > > > > > > Eh this wont work, it's the wrong entry... Here's a temporary
> > > > > > > > work-around.
> > > > > > > > 
> > > > > > > > diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
> > > > > > > > index c89f0d3..108202b 100644
> > > > > > > > --- a/drivers/ide/ide-io.c
> > > > > > > > +++ b/drivers/ide/ide-io.c
> > > > > > > > @@ -822,6 +822,7 @@ void ide_map_sg(ide_drive_t *drive, struct request *rq)
> > > > > > > >  		return;
> > > > > > > >  
> > > > > > > >  	if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
> > > > > > > > +		sg_init_table(hwif->sg_table, hwif->sg_max_nents);
> > > > > > > >  		hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
> > > > > > > >  	} else {
> > > > > > > >  		sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
> > > > > > > 
> > > > > > > That's the exact patch I'm about to boot test :-)
> > > > > > 
> > > > > > That should work - once you verify that, would you mind testing this one
> > > > > > as well? Thanks!
> > > > > 
> > > > > This one works here too, thanks.
> > > > 
> > > > BTW, we avoid calling sg_init_table() for every I/O request due to Jens'
> > > > trick. And Jens will remove the code to clear sg_dma_len/addr in
> > > > blk_rq_map_sg(). So sparc64 iommu needs to do that for itself?
> > > > 
> > > > http://marc.info/?l=linux-scsi&m=119261920425120&w=2
> > > 
> > > It does - Dave, do you agree with the patch? I think it should be added,
> > > so that sparc64 isn't the odd-arch-out in this respect. I've tentatively
> > > applied the patch, Davem?
> > 
> > BTW, you sure that should not include to check whether sg_next() returns
> > non-NULL?
> 
> Yeah, the following part checks that:
> 
> +	if (dma_sg != sg) {

Ah good, thanks for confirming.

-- 
Jens Axboe