On 04/11/12 16:10, Martin K. Petersen wrote: > diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c > index 2cfcbff..386f0c5 100644 > --- a/drivers/scsi/scsi_error.c > +++ b/drivers/scsi/scsi_error.c > @@ -835,7 +835,7 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, unsigned char *cmnd, > > scsi_eh_restore_cmnd(scmd, &ses); > > - if (sdrv->eh_action) > + if (sdrv && sdrv->eh_action) > rtn = sdrv->eh_action(scmd, cmnd, cmnd_size, rtn); > > return rtn; > diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h > index 377df4a..1e11985 100644 > --- a/include/scsi/scsi_cmnd.h > +++ b/include/scsi/scsi_cmnd.h > @@ -134,6 +134,9 @@ struct scsi_cmnd { > > static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd) > { > + if (!cmd->request->rq_disk) > + return NULL; > + > return *(struct scsi_driver **)cmd->request->rq_disk->private_data; > } What if the rq_disk pointer is cleared by another kernel thread after it has been checked but before it is used ? Personally I would feel more comfortable if code inside sd_eh_action() / sd_show_max_medium_access_timeouts() / sd_store_max_medium_access_timeouts() would be moved inside the SCSI core such that scsi_send_eh_cmnd() doesn't have to access struct scsi_driver. Bart. -- 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