Re: Issue #5876 : assertion failure in rbd_img_obj_callback()

[Olivier Bonvalet <ceph.list@daevel.fr>]

Le mardi 25 mars 2014 à 15:24 -0500, Alex Elder a écrit :
> On 03/25/2014 03:21 PM, Olivier Bonvalet wrote:
> > Le mardi 25 mars 2014 à 22:18 +0200, Ilya Dryomov a écrit :
> >> On Tue, Mar 25, 2014 at 9:03 PM, Alex Elder <elder@ieee.org> wrote:
> >>> On 03/25/2014 01:53 PM, Olivier Bonvalet wrote:
> >>>> Le mardi 25 mars 2014 à 12:43 -0500, Alex Elder a écrit :
> >>>>> Please try applying this, on top of the previous patch.
> >>>>> If you can then reproduce the problem we'll have a bunch
> >>>>> of new information about the particular request that's
> >>>>> leading to the failure.  That might tell us what more we
> >>>>> can do to find the root cause.  Thank you.
> >>>>>
> >>>>>                                      -Alex
> >>>>>
> >>>>> PS  I hope my mailer doesn't botch the long lines.  It might.
> >>>>>
> >>>>
> >>>> Here the execution will continue, no more kernel panic after this
> >>>> debugging display. Is it wanted ?
> >>>
> >>>
> >>> I guess it should panic.  I'm glad you mentioned this.
> >>
> >> Just in case, if you haven't done it already: stick rbd_assert(0);
> >> after the last printk in that if statement, so it looks like this:
> >>
> >> if (which != img_request->next_completion) {
> >>         printk("%s: bad image object request information:\n", __func__);
> >>         printk("obj_request %p\n", obj_request);
> >>         printk("    ->object_name <%s>\n", obj_request->object_name);
> >>         ...
> >>
> >>         printk("img_request %p\n", img_request);
> >>         printk("    ->snap 0x%016llx\n", img_request->snap_id);
> >>         ...
> >>         printk("    ->result %d\n", img_request->result);
> >>
> >>         rbd_assert(0);
> >> }
> >>
> >> Thanks,
> >>
> >>                 Ilya
> >>
> > 
> > Without the rbd_assert(0), I add this hang :
> > 
> > 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255933] rbd_img_obj_callback: bad image object request information:
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255938] obj_request ffff88025a2b3c48
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255940]     ->object_name <rb.0.1536881.238e1f29.000000000439>
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255941]     ->offset 0
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255943]     ->length 28672
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255944]     ->type 0x1
> 		BIO request
> 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255945]     ->flags 0x3
> 	IMG_DATA, KNOWN
> 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255946]     ->which 1
> 	Second object in the request
> 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255948]     ->xferred 28672
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255949]     ->result 0
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255950] img_request ffff8802536c4a60
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255952]     ->snap 0xffff880257f85ec0
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255953]     ->offset 4534026240
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255954]     ->length 45056
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255955]     ->flags 0x1
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255957]     ->obj_request_count 1
> 	!!! There is only one request... (?)
> 
> So obj_request_count might be getting computed incorrectly.
> 
> 					-Alex
> 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255958]     ->next_completion 2
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255959]     ->xferred 45056
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255960]     ->result 0
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255962] 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255962] Assertion failure in rbd_img_obj_callback() at line 2162:
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255962] 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255962] 	rbd_assert(which < img_request->obj_request_count);
> > Mar 25 21:17:58 murmillia kernel: [ 2205.255962] 
> > Mar 25 21:17:58 murmillia kernel: [ 2205.256141] ------------[ cut here ]------------
> > Mar 25 21:17:58 murmillia kernel: [ 2205.256178] kernel BUG at drivers/block/rbd.c:2162!
> > 
> > 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


Here I was migrating (xen live migrate) ~20 VM from one host to
"murmillia", just after booting "murmillia" on the new kernel.

--
To unsubscribe from this list: send the line "unsubscribe ceph-devel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html