Re: kernel BUG at ide-cd.c:1726 in 2.6.24-03863-g0ba6c33 && -g8561b089

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

Hi,

On Wednesday 30 January 2008, Kiyoshi Ueda wrote:
> Hi Bart, 
> 
> On Tue, 29 Jan 2008 14:22:53 -0800, Roland Dreier wrote:
> > Hi, I saw the same BUG from ide-cd on one of my systems.  I applied
> > the debugging patch to replace the BUG with blk_dump_rq_flags(), and I
> > got the output below (full boot log and .config attached to this
> > email).
> > 
> > Please let me know if there's anything else that would help debug the
> > problem.
> 
> Thank you for the information, Roland.
> 
>  
> > [    4.072271] Uniform CD-ROM driver Revision: 3.20
> > [    4.098236] ide-cd: rq still having bio: dev hda: type=2, flags=114c8
> > [    4.100269]
> > [    4.100269] sector 1949759, nr/cnr 0/0
> > [    4.100269] bio ffff8102418cc600, biotail ffff8102418cc600, buffer 0000000000000000, d8
> > [    4.100269] cdb: 12 00 00 00 fe 00 00 00 00 00 00 00 00 00 00 00
> > [    4.101005] ide-cd: rq still having bio: dev hda: type=2, flags=114c8
> > [    4.104269]
> > [    4.104269] sector 1949759, nr/cnr 0/0
> > [    4.104269] bio ffff8102418cc600, biotail ffff8102418cc600, buffer 0000000000000000, d2
> > [    4.104269] cdb: 12 00 00 00 fe 00 00 00 00 00 00 00 00 00 00 00
> > [    4.109203] ide-cd: rq still having bio: dev hda: type=2, flags=114c8
> > [    4.112270]
> > [    4.112270] sector 1949759, nr/cnr 0/0
> > [    4.112270] bio ffff8102418cc600, biotail ffff8102418cc600, buffer 0000000000000000, d8
> > [    4.112270] cdb: 12 01 00 00 fe 00 00 00 00 00 00 00 00 00 00 00
> > [    4.112945] ide-cd: rq still having bio: dev hda: type=2, flags=114c8
> > [    4.116270]
> > [    4.116270] sector 1949759, nr/cnr 0/0
> > [    4.116270] bio ffff8102418cc600, biotail ffff8102418cc600, buffer 0000000000000000, d2
> > [    4.116270] cdb: 12 01 00 00 fe 00 00 00 00 00 00 00 00 00 00 00
> 
> Bart,
> This means that the rq still has a bio even after DRQ_STAT is cleared.
> The original ide-cd code was calling only end_that_request_last() there.
> So I thought that the rq should have no bio when DRQ_STAT is cleared,
> otherwise the bio leaks.
> 
> Was my understanding wrong and is that correct behavior in ide-cd?

Added Borislav to cc:.

PS I'm extremely busy with "real-life" (unfortunately IDE hacking is not
my paid job) and the friday is the earliest date on which I would be able
to look in detail into this problem and other outstanding IDE stuff, sorry.

Thanks,
Bart