Re: [patch] cciss: Fix problem that deleting multiple logical drives could cause a panic

scameron
2008-12-16T20:49:55Z

On Tue, Dec 16, 2008 at 09:27:30PM +0100, Jens Axboe wrote:
> On Tue, Dec 16 2008, scameron@beardog.cca.cpqcorp.net wrote:
> >
> > Fix problem that deleting multiple logical drives could cause a panic.
>
> This looks like a 2.6.28 candidate, correct?

Yes, and we would like to get it in anywhere else it needs to go
(backport to 2.6.27.x? if that makes sense.)

It fixes a panic which can be easily reproduced in the following
way: Just create several "arrays," each with multiple logical
drives via hpacucli, then delete the first array, and it will blow
up in deregister_disk(), in the call to get_host() when it tries to
dig the hba pointer out of a NULL queue pointer.

The problem has been present since my code to make
rebuild_lun_table behave better went in.

-- steve

>
> >
> > Signed-off-by: Stephen M. Cameron <scameron@beardog.cca.cpqcorp.net>
> > ---
> >
> > drivers/block/cciss.c | 5 +++++
> > 1 file changed, 5 insertions(+)
> >
> > diff -puN drivers/block/cciss.c~fix_rebuild_lun_table_bug drivers/block/cciss.c
> > --- linux-2.6.28-rc8/drivers/block/cciss.c~fix_rebuild_lun_table_bug 2008-12-16 14:00:52.000000000 -0600
> > +++ linux-2.6.28-rc8-root/drivers/block/cciss.c 2008-12-16 14:00:52.000000000 -0600
> > @@ -1693,6 +1693,11 @@ static int rebuild_lun_table(ctlr_info_t
> > for (i = 0; i <= h->highest_lun; i++) {
> > int j;
> > drv_found = 0;
> > +
> > + /* skip holes in the array from already deleted drives */
> > + if (h->drv[i].raid_level == -1)
> > + continue;
> > +
> > for (j = 0; j < num_luns; j++) {
> > memcpy(&lunid, &ld_buff->LUN[j][0], 4);
> > lunid = le32_to_cpu(lunid);
> > _
>
> --
> Jens Axboe
>