Re: CPU lock-ups with 4.12.0+ kernels related to usb_storage

[Arthur Marsh <arthur.marsh@xxxxxxxxxxxxxxxx>]

Arthur Marsh wrote on 14/07/17 04:18:
> Alan Stern wrote on 14/07/17 02:30:
>
> > All right.  In the meantime, changing usb-storage won't hurt.
> > Arthur, can you test the patch below?
> >
> > Alan Stern
> >
> >
> >
> > Index: usb-4.x/drivers/usb/storage/usb.c
> > ===================================================================
> > --- usb-4.x.orig/drivers/usb/storage/usb.c
> > +++ usb-4.x/drivers/usb/storage/usb.c
> > @@ -315,6 +315,7 @@ static int usb_stor_control_thread(void
> >   {
> >       struct us_data *us = (struct us_data *)__us;
> >       struct Scsi_Host *host = us_to_host(us);
> > +    struct scsi_cmnd *srb;
> >       for (;;) {
> >           usb_stor_dbg(us, "*** thread sleeping\n");
> > @@ -330,6 +331,7 @@ static int usb_stor_control_thread(void
> >           scsi_lock(host);
> >           /* When we are called with no command pending, we're done */
> > +        srb = us->srb;
> >           if (us->srb == NULL) {
> >               scsi_unlock(host);
> >               mutex_unlock(&us->dev_mutex);
> > @@ -398,14 +400,11 @@ static int usb_stor_control_thread(void
> >           /* lock access to the state */
> >           scsi_lock(host);
> > -        /* indicate that the command is done */
> > -        if (us->srb->result != DID_ABORT << 16) {
> > -            usb_stor_dbg(us, "scsi cmd done, result=0x%x\n",
> > -                     us->srb->result);
> > -            us->srb->scsi_done(us->srb);
> > -        } else {
> > +        /* was the command aborted? */
> > +        if (us->srb->result == DID_ABORT << 16) {
> >   SkipForAbort:
> >               usb_stor_dbg(us, "scsi command aborted\n");
> > +            srb = NULL;    /* Don't call srb->scsi_done() */
> >           }
> >           /*
> > @@ -429,6 +428,13 @@ SkipForAbort:
> >           /* unlock the device pointers */
> >           mutex_unlock(&us->dev_mutex);
> > +
> > +        /* now that the locks are released, notify the SCSI core */
> > +        if (srb) {
> > +            usb_stor_dbg(us, "scsi cmd done, result=0x%x\n",
> > +                    srb->result);
> > +            srb->scsi_done(srb);
> > +        }
> >       } /* for (;;) */
> >       /* Wait until we are told to stop */

Hi, just to confirm no further lock-ups occurred in the last 4 days with 
this patch applied.

Arthur.