Re: Kernel Oops while closing iSCSI connection [transport_free_dev_tasks]

["Nicholas A. Bellinger" <nab@xxxxxxxxxxxxxxx>]

On Mon, 2012-04-09 at 23:26 +0200, Henning Becker wrote:
> Am Mittwoch, 4. April 2012, 14:08:36 schrieb Nicholas A. Bellinger:
> > On Tue, 2012-04-03 at 08:56 +0200, Henning Becker wrote:
> > > Am Montag, 2. April 2012, 19:27:25 schrieben Sie:
> > > > On Sat, 2012-03-31 at 21:49 +0200, Henning Becker wrote:
> > > > > Hello,
> > > > > I'm using LIO iSCSI target on top of a pacemaker cluster, to provide a
> > > > > redundant replicated storage.
> > > > > 
> > > > > I randomly get Kernel Oops in transport_free_dev_tasks, while moving
> > > > > the
> > > > > target from one node to the other.
> > > > > 
> > > > > Kernel log says the following (Kernel 3.3.0-rc6):
> > > > > http://pastebin.com/tvm3tK7Z Another log (Kernel 3.2.0):
> > > > > http://pastebin.com/wMNER3We
> > > > > 
> > > > > Distribution is Debian and it seems only to happen, if there is an
> > > > > iscsi
> > > > > connection.
> > > > > 
> > > > > Any hints?
> > > > 
> > > > Hello Henning,
> > > > 
> > > > It would be helpful to know a bit more about the target configuration
> > > > that is triggering this bug, and what the cluster resource callbacks are
> > > > being invoked to individual /sys/kernel/config/target/iscsi/ endpoint
> > > > shutdown to perform the move..
> > > 
> > > Hello Nicholas,
> > > I've written an inotify log of /sys/kernel/config for you. It's here:
> > > http://pastebin.com/vNEe6vR5
> > 
> > Hi again Henning,
> > 
> > Thanks for the setup info and the nice inotify log.
> > 
> > > It seems, the Oops happens while disabling target (writing "0" to
> > > tpgt_1/enable)
> > 
> > Ok, please verify if this session is attached to an explicit fabric
> > initiator NodeACL (iSCSI InitiatorName) configfs group, or attached to a
> > dynamically generated se_node_acl->acl_group using the TPG attrib
> > generate_node_acl=1 to allow 'demo mode' operation (eg: all initiators
> > can login to the endpoint)..?
> 
> Hi Nicholas,
> thanks for your fast answer and sorry, that it took so long for me.
> 
> I'm currently using demo mode without any NodeACL. Portal group is initiated 
> with lio_node --permissive and write protection is disabled by writing 0 to 
> attrib/demo_mode_write_protect. And yes, generate_node_acl is '1'.
> 

Hi Henning,

Thanks additional for the feedback on your setup.

> Should I test with ACLs enabled?
> 

At this point I'm still thinking it's something to do with active I/O
shutdown with sessions attached to dynamic ACLs with demo-mode
(generate_node_acls=1) enabled..

Being able to verify if the issue is reproducible with Explict NodeACLs
for your setup would help me further isolate down the problem space.

Thanks,

--nab



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