Re: oops w/ 2.6.2-mm1 on ppc32

[Andrew Morton <akpm@osdl.org>]

Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
>
> On Sun, 2004-02-15 at 18:41, Marc Heckmann wrote:
> > It happened while the machine was waking up from sleep. There were no
> > UDF or ISO filesystems mounted at the time, in fact, there wasn't even
> > a cd in the drive. The "autorun" process was running though (polls the
> > cdrom drive, to see if a disc has been inserted...). There were some
> > request timeouts on the cdrom drive (hdc) just before, it went to
> > sleep (system was idle at the time, I wasn't even at home).
> > 
> > Here is the kernel output before and after the machine went to sleep. The Oops
> > is at the bottom.
> 
> Looks like CD went berserk, and something didn't deal with the
> error correctly... I don't know those code path in there
> very well... Can you paste more of the ide-cd errors,
> those are weird.

Note that isofs_fill_super() calls sb_bread() before setting the blocksize.
For this it is relying on blockdev.bd_block_size being set up
appropriately.

Which all tends to imply that the underlying queue's ->hardsect_size is
very wrong.

The code which is responsible for setting up the queue's hardsect_size
appears to live in cdrom_read_toc():

	/* Check to see if the existing data is still valid.
	   If it is, just return. */
	(void) cdrom_check_status(drive, sense);

	if (CDROM_STATE_FLAGS(drive)->toc_valid)
		return 0;

	/* Try to get the total cdrom capacity and sector size. */
	stat = cdrom_read_capacity(drive, &toc->capacity, &sectors_per_frame,
				   sense);
	if (stat)
		toc->capacity = 0x1fffff;

	set_capacity(drive->disk, toc->capacity * sectors_per_frame);
	blk_queue_hardsect_size(drive->queue,
				sectors_per_frame << SECTOR_BITS);

I'm wondering about that `return 0;' in there.  That will return "success"
even though we haven't set up half the things which should have been set
up.

Jens, should we be returning some sort of error code there?