[Bug 21559] "scheduling while atomic" with brctl and NFS-mounted root

[bugzilla-daemon at bugzilla.ubuntu.com]

Please do not reply to this email.  You can add comments at
http://bugzilla.ubuntu.com/show_bug.cgi?id=21559
Ubuntu | linux





------- Additional Comments From gjc at inescporto.pt  2005-12-28 16:13 UTC -------
(In reply to comment #10)
> Of course it is a NFS problem, the error occurs when the interface brings itself
> down for bridging and then does an mdelay, which allows NFS to be scheduled and
> then it tries to schedule some work, and in doing so, causes this bug.

  OK.  What I meant is that it's not a NFS-when-used-as-root-filesystem problem.

> 
> IMO, this problem is related to rhine and NFS in general. The call down for the
> rhine driver to perform the action that bridging needs does the mdelay() (which
> not all ethernet drivers will do). The briding code says that it handles this
> before performing this call (scheduling), but the problem is that rhine does a
> spinlock during this call, so it cannot handle the scheduling (spinlocks are
> atomic). I'm inclined to think the rhine driver is at fault here.

  I'm no kernel hacker, so no comment :P

> 
> Question, are you using NFSv4 or NFSv3? The code paths are quite different
> between the two during the nfs_do_access().

  'mount' reports:
192.168.30.66:/var/lib/lessdisks on / type nfs
(rw,v3,rsize=32768,wsize=32768,hard,tcp,nolock,addr=192.168.30.66)

So I imagine that v3 means NFS version 3...

PS: today I got lucky once and managed to run my bridge script without the
kernel locking (in spite of the usual traces in dmesg); but I rebooted the
machine and tried again and it locked up this time.  So it's a problem that
happens most of the times, but not always.


-- 
Configure bugmail: http://bugzilla.ubuntu.com/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug, or are watching the QA contact.