Re: [BUG] AS-ioscheduler: kernel panic at as_exit_queue

[Jens Axboe <jens.axboe@oracle.com>]

On Thu, Jan 08 2009, ???? ?? wrote:
> 
> Hi Nick & Jens,
> 
>  I met a Kernel Panic with AS, the panic pc is at as_exit_queue, and panic
>  when the function check whether the fifo_list[REQ_SYNC] and
>  fifo_list[REQ_ASYNC] are empty or not, it would Panic if the lists are not
> empty.
> 
>       The k-panic happened when I plugged out my Micro-SD memory card
>  from my phone, the log has been attached onto this mail.
> 
>       I guess there may be some conflicts between AS and Hot-plug
>  mechanism, so I read the code of AS code by code to find anything
>  suspicious. I find that AS might does not consider that do any operations
>  to the fifo_lists when the device driver try to exit its elevator, so there
>  is possibility that when device try to exit, the fifo_lists are not empty,
>  and happen kernel panic, though the possibility is really really very
>  small:).
> 
>       Unfortunately, I have met such k-panic more than two times, so I
>  think I should get your suggestions first, and then try to do some works
>  for this problem:) Look forward for your reply:)
> 
> My Linux version :  2.6.25

Please try a newer version, I _think_ this was fixed in sd. CC'ing
Pierre, just in case.

-- 
Jens Axboe