On 01/28/2015 10:46 AM, michaelc@xxxxxxxxxxx wrote: > From: Mike Christie <michaelc@xxxxxxxxxxx> > > This fixes a regression caused by commit > 1d5203284d8acbdfdf9b478d434450b34f338f28 > > The bug is that the alua detach() callout will try to access the > sddev->scsi_dh_data, but we have already set it to NULL. This patch > moves the clearing of that field to after detach() is called. > > It looks like the regression was added during 3.19 development, > so it has not been in a released kernel, and so I did not cc > stable. > > Signed-off-by: Mike Christie <michaelc@xxxxxxxxxxx> > > --- > drivers/scsi/device_handler/scsi_dh.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/scsi/device_handler/scsi_dh.c b/drivers/scsi/device_handler/scsi_dh.c > index 1dba62c..1efebc9 100644 > --- a/drivers/scsi/device_handler/scsi_dh.c > +++ b/drivers/scsi/device_handler/scsi_dh.c > @@ -136,11 +136,12 @@ static void __detach_handler (struct kref *kref) > struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; > struct scsi_device *sdev = scsi_dh_data->sdev; > > + scsi_dh->detach(sdev); > + > spin_lock_irq(sdev->request_queue->queue_lock); > sdev->scsi_dh_data = NULL; > spin_unlock_irq(sdev->request_queue->queue_lock); > > - scsi_dh->detach(sdev); > sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name); > module_put(scsi_dh->module); > } > Errm. We save the contents first: > struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; Then set the pointer to NULL: > sdev->scsi_dh_data = NULL; and then call 'detach': > scsi_dh->detach(sdev); So scsi_dh is _not_ NULL, hence it shouldn't oops. NACK. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
