Re: [PATCH 1/2] Disk hot removal causing oopses and fixes

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Jarkko Lavinen wrote:
> Hi Steven
> 
> Sorry for late reply.
> 
>> It has to reference-count its objects so that they are not freed as long
>> as they are used by upper layers,
> 
> The block layer and device removal seems to be designed from
> top-down approach.  Althouh disc is referenced from
> __blkdev_get(), disc's request queue is not.  Also
> blk_cleanup_queue() calls elevator_exit() without caring if
> anyone still uses the elevator.
[...]

I still don't understand how there can be a problem here.  Shouldn't the
sequence be:

 1. low-level determines that a device went away
 2. low-level takes note that from now on no new requests must be
    enqueued anymore
 3. low-level calls blk_cleanup_queue
 4. blk_cleanup_queue waits until remaining requests are done
    (it calls blk_sync_queue)
 5. blk_cleanup_queue cleans up block layer data
 6. low-level can now clean up/ free its own data

Does the MMC layer miss step 2?  Because without this, step 4 would be
in vain.
-- 
Stefan Richter
-=====-==--= =-== ---==
http://arcgraph.de/sr/
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux