Hi, I saw these two elements are included in struct scsi_device, i.e. device_busy and device_blocked. But I am wondering what the difference between these two variables are?Or in other words, what do these two variables mean? struct scsi_device { struct Scsi_Host *host; struct request_queue *request_queue; /* the next two are protected by the host->host_lock */ struct list_head siblings; /* list of all devices on this host */ struct list_head same_target_siblings; /* just the devices sharing same target id */ /* this is now protected by the request_queue->queue_lock */ unsigned int device_busy; /* commands actually active on * low-level. protected by queue_lock. */ ... unsigned int device_blocked; /* Device returned QUEUE_FULL. */ ... } Thanks Jason - 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