Regression with ZFS on recent current

[Guido Falsi]

Hi!

While testing portshaker I found a regression in latest current.

portshaker depends on ZFS(when enabling ZFS support) remounting
filesystems on the fly when changing the mountpoint property. This is
working as expected on 9.x while on 10-current is not working. Problem
has appeared sometime before October 3rd.

Here is some sample output from a9.x machine and a 10-current one:

root at micro:~ [0]# uname -a
FreeBSD micro.madpilot.net 9.1-PRERELEASE FreeBSD 9.1-PRERELEASE #0
r239180: Sat Aug 11 00:14:47 CEST 2012
root at micro.madpilot.net:/usr/obj/usr/src/sys/MICRO  amd64
root at micro:~ [0]# zfs create tank/test
root at micro:~ [0]# touch /test/baz
root at micro:~ [0]# zfs set mountpoint=/foo tank/test
root at micro:~ [0]# ls -ld /foo
drwxr-xr-x  2 root  wheel  3 Oct 17 19:18 /foo
root at micro:~ [0]# ls -l /foo/
total 1
-rw-r--r--  1 root  wheel  0 Oct 17 19:18 baz
root at micro:~ [0]# zfs list tank/test
NAME        USED  AVAIL  REFER  MOUNTPOINT
tank/test   144K   826G   144K  /foo


root at marvin:~ [0]# uname -a
FreeBSD marvin.madpilot.net 10.0-CURRENT FreeBSD 10.0-CURRENT #7
r241638: Wed Oct 17 14:33:18 CEST 2012
root at marvin.madpilot.net:/usr/obj/usr/src/sys/MARVIN  amd64
root at marvin:~ [0]# zfs create tank/test
root at marvin:~ [0]# touch /test/baz
root at marvin:~ [0]# zfs set mountpoint=/foo tank/test
root at marvin:~ [0]# ls -ld /foo
ls: /foo: No such file or directory
root at marvin:~ [1]# ls -l /foo/
ls: /foo/: No such file or directory
root at marvin:~ [1]# ls -ld /test
drwxr-xr-x  2 root  wheel  3 Oct 17 19:19 /test
root at marvin:~ [0]# zfs list tank/test
NAME        USED  AVAIL  REFER  MOUNTPOINT
tank/test    31K   240G    31K  /foo


Is this known? is the new behavior expected?

Am I doing something stupid?

Thanks in advance

-- 
Guido Falsi <mad at madpilot.net>