So should a request queue be in bypass mode when the device is being detached and queue is being unregistereed because requests can get queued up? On Mon, Sep 8, 2014 at 9:51 AM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Sun, 7 Sep 2014, Shirish Pargaonkar wrote: > >> I think the problem is, when a gendisk is detached, its request queue >> is not put in bypass mode >> cause when it is re-attached, code tries to put it out of bypass mode, >> hence the warning. >> >> So either of these should work, I have not tested it, just coded it up. > > I'm pretty sure that both of your solutions are wrong. > > Jens and James, it appears the problem is in blk_register_queue(). The > code does this: > > /* > * Initialization must be complete by now. Finish the initial > * bypass from queue allocation. > */ > queue_flag_set_unlocked(QUEUE_FLAG_INIT_DONE, q); > blk_queue_bypass_end(q); > > This doesn't work well if the queue is unregistered later and then > registered again -- which is what happens when the sd driver is unbound > from a device and then bound again. It looks like the code should be: > > if (!queue_flag_test_and_set(QUEUE_FLAG_INIT_DONE, q)) > blk_queue_bypass_end(q); > > Do you agree? If so, I'll send in patch. > > Alan Stern > -- 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
