Re: [PATCH] scsi: libsas: Grab the host lock in sas_ata_device_link_abort()

[Jason Yan]

On 2022/12/21 8:36, Damien Le Moal wrote:
> On 2022/12/20 23:59, John Garry wrote:
> > On 20/12/2022 12:53, Xingui Yang wrote:
> > > Grab the host lock in sas_ata_device_link_abort() before calling
> >
> > This is should be the ata port lock, right? I know that the ata comments
> > say differently.
> >
> > > ata_link_abort(), as the comment in ata_link_abort() mentions.
> >
> > Can you please add a fixes tag?
> >
> > > Signed-off-by: Xingui Yang <yangxingui@xxxxxxxxxx>
> >
> > Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>
> >
> > > ---
> > >    drivers/scsi/libsas/sas_ata.c | 3 +++
> > >    1 file changed, 3 insertions(+)
> > >
> > > diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
> > > index f7439bf9cdc6..4f2017b21e6d 100644
> > > --- a/drivers/scsi/libsas/sas_ata.c
> > > +++ b/drivers/scsi/libsas/sas_ata.c
> > > @@ -889,7 +889,9 @@ void sas_ata_device_link_abort(struct domain_device *device, bool force_reset)
> > >    {
> > >    	struct ata_port *ap = device->sata_dev.ap;
> > >    	struct ata_link *link = &ap->link;
> > > +	unsigned long flags;
> > >    
> > > +	spin_lock_irqsave(ap->lock, flags);
> > >    	device->sata_dev.fis[2] = ATA_ERR | ATA_DRDY; /* tf status */
> > >    	device->sata_dev.fis[3] = ATA_ABORTED; /* tf error */
> > >    
> > > @@ -897,6 +899,7 @@ void sas_ata_device_link_abort(struct domain_device *device, bool force_reset)
> > >    	if (force_reset)
> > >    		link->eh_info.action |= ATA_EH_RESET;
> > >    	ata_link_abort(link);
>
> Really need to add lockdep annotations in libata to avoid/catch such bugs...
> Will work on that.

Actually in libata there are many places calling ata_link_abort() not 
holding port lock. And some places are holding the real host 
lock(ata_host->lock) while calling ata_link_abort(). So if you add the 
lockdep annotations, there may be too many warnings. If these are real 
issues, we should fix them first.

Thanks,
Jason