Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Tue, 2006-10-10 at 10:20 +0200, Philipp Reisner wrote:
> 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.
So, will it be used if linux-2.6.15 has connector code in it? I put some
printks in drbd/connector.c cn_add_callback. And didn't see them while
loading the module ( I have connector in kernel).
>
> -Phil
--
Milind
"The world is divided into one group: those who start counting at 0,
and those who don't."