kern/159010: zfsv28 serves bad device nodes via nfs on FreeBSD 8.2

[Gerrit Kühn]

>Number:         159010
>Category:       kern
>Synopsis:       zfsv28 serves bad device nodes via nfs on FreeBSD 8.2
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jul 18 15:20:10 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Gerrit Kühn
>Release:        8.2-stable as of 15th of July 2011
>Organization:
AEI/MPG
>Environment:
FreeBSD mclane.rt.aei.uni-hannover.de 8.2-STABLE FreeBSD 8.2-STABLE #0: Thu Jul 14 14:09:47 CEST 2011     root at mclane.rt.aei.uni-hannover.de:/usr/obj/usr/src/sys/GENERIC  amd64

>Description:
Copied from my email on freebsd-stable:



I guess I found the root of all evil now: device nodes on zfs!

This is how a linux /dev/console looked on the 8.0-FreeBSD server on
zfsv15:

crw-------  1 root  wheel    5,   1 Oct 28	2010 /tank/diskless/gco-fe2/dev/console


Now, after updating to FreeBSD-8.2 and zfsv28 it looks like this on the server:

crw-r--r--  1 root  wheel  255, 0xffff00ff Jul 18 16:33 /tank/diskless/pt-fe2/dev/console


Strange enough, the Linux client still displays the correct values when using "ls -la", but it refuses to work properly.
I tried creating new device nodes from the client side with mknod and I tried getting correct ones from a backup, but they always end up being broken. Even moving the directories over to a ufs volume leaves them unusable:

crw-r--r--  1 root  wheel    0,   0 Jul 18 16:33 /tmp/console


Luckily, I am back into business now with my machines, because moving the stuff from zfs to ufs and dropping in a correct version of /dev on the ufs side works just fine.

However, it would be great if this could be fixed, because I do not have many ufs partitions left these days...
>How-To-Repeat:
Upgrade filesystems containing device nodes (Linux diskless client in this case) to zfsv28 on FreeBSD 8.2-stable.
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: