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

[Alex Elder <elder@ieee.org>]

On 03/25/2014 03:21 PM, Olivier Bonvalet wrote:
> 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
> Mar 25 21:17:58 murmillia kernel: [ 2205.255945]     ->flags 0x3
> Mar 25 21:17:58 murmillia kernel: [ 2205.255946]     ->which 1
> 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

The image request has IMG_REQ_CHILD set.  That means it's a request
sent to a parent image.

I see one thing that I'm suspicious of, but I'll need to look at it
a bit to see if it's really a problem.

In rbd_parent_request_destroy(), should this last line:
        rbd_img_request_destroy(kref);
be this instead?
	rbd_img_request_put(parent_request);

And get rid of this line above that:
        img_request_child_clear(parent_request);

Something to look at.  Also the fact that it's a parent
request with two objects involved seems strange, but
again, I'm just speculating at this point.

					-Alex

> Mar 25 21:17:58 murmillia kernel: [ 2205.255957]     ->obj_request_count 1
> 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