[DRBD-user] drbd-8.0pre5

Philipp Reisner philipp.reisner at linbit.com
Tue Oct 10 10:20:37 CEST 2006


Am Montag, 9. Oktober 2006 21:18 schrieb Lars Ellenberg:
> / 2006-10-09 15:13:30 +0530
>
> \ Milind Dumbare:
> > Hi all,
> > 	I have x86_64 ubuntu and I untared drbd-8.0pre5 and tried compiling it.
> > I went good. When I insmod the drbd.ko it gave me following stack trace,
> > what could have went wrong?
> >
> > 	I tested previous drbd pre releases. They work fine.
> >
> > Unable to handle kernel NULL pointer dereference at 0000000000000000
> > RIP:
>

To Milind:
This is a x86 (32bit) Kubuntu box:

root at duck:/home/phil/src/drbd08/user# uname -a
Linux duck 2.6.15-27-386 #1 PREEMPT Sat Sep 16 01:51:59 UTC 2006 i686 GNU/Linux

Loading the module failed at first:

[17181212.412000] drbd: Unknown symbol cn_netlink_send
[17181212.412000] drbd: Unknown symbol cn_del_callback
[17181212.412000] drbd: Unknown symbol cn_add_callback

Then I realized that I have to load the "cn" module.
'modprobe cn'

[17181361.352000] drbd: initialised. Version: 8.0pre5 (api:84/proto:83)
[17181361.352000] drbd: SVN Revision: 2520M build by phil at duck, 2006-10-10 10:07:02
[17181361.352000] drbd: registered as block device major 147

Then the drbd module loaded.

./drbdadm up r0

root at duck:/home/phil/src/drbd08/user# ./drbdsetup /dev/drbd0 show
disk {
        size                    0s _is_default;
        on-io-error             detach;
        fencing                 dont-care _is_default;
}
net {
        timeout                 60 _is_default;
        max-epoch-size          2048 _is_default;
        max-buffers             2048 _is_default;
        unplug-watermark        128 _is_default;
        connect-int             10 _is_default;
        ping-int                10 _is_default;
        sndbuf-size             131070 _is_default;
        ko-count                0 _is_default;
        after-sb-0pri           disconnect _is_default;
        after-sb-1pri           disconnect _is_default;
        after-sb-2pri           disconnect _is_default;
}
syncer {
        rate                    10240k;
        after                   -1 _is_default;
        al-extents              257;
}
protocol C;
_this_host {
        device                  "/dev/drbd0";
        disk                    "/dev/duck-vg/drbd0";
        meta-disk               "/dev/duck-vg/drbd0-md" [ 0 ];
        address                 10.9.9.102:7788;
}
_remote_host {
        address                 192.168.22.12:7788;
}

So, I can not reporduce this on my 32bit kubuntu box here.
What exact kernel version are you using? Do you have one with the connector (cn)
ported back by ubuntu? In case you have an older one you will use 
the connector code that is packaged with drbd.

> possibly in-kernel buffer overflow, fixed by revision 2490 ?
> (did not show up on our test systems, probably because of different
> compiler decisions regarding alignment and sizing of buffers.

To Lars:
No, this one is something else.

I guess Milind is using an older kubuntu kernel, ... and the bug is in the
back-ported connector code, we packaged with drbd.

-Phil
-- 
: Dipl-Ing Philipp Reisner                      Tel +43-1-8178292-50 :
: LINBIT Information Technologies GmbH          Fax +43-1-8178292-82 :
: Schönbrunnerstr 244, 1120 Vienna, Austria    http://www.linbit.com :



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