kern/174877: mountd fails to work inside init_chroot

[Tak Pui Lou]

>Number:         174877
>Category:       kern
>Synopsis:       mountd fails to work inside init_chroot
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Jan 01 07:30:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Tak Pui Lou
>Release:        FreeBSD 9.1-PRERELEASE amd64
>Organization:
>Environment:
System: FreeBSD neutron.lbl.gov 9.1-PRERELEASE FreeBSD 9.1-PRERELEASE #0 r244804M: Fri Dec 28 19:05:54 PST 2012 lou at neutron.lbl.gov:/usr/obj/usr/src/sys/GENERIC amd64

>Description:

Since some revision after r231239, mountd fails to work inside a chroot started by an mfsroot preloaded image's init.

>How-To-Repeat:
Load a mfsroot preloaded image from loader.conf and set init_chroot=/system. /system is a zfs boot filesystem and has other zfs filesystems (e.g. /etc, /bin, /lib, /libexec, ... ) mounted under its subdirectories. Boot this and export filesystem under /system.

I think there is some changes to make mountd to work with jail and these changes make mountd lookup the exports path outside init_chroot instead of inside init_chroot. Therefore, it gives the following error messages:

Dec 31 21:33:45 ------- mountd[1990]: can't export /export 
Dec 31 21:33:45 ------- mountd[1990]: bad exports list line /export

>Fix:

The export files and sharenfs parameters works when mountd is not inside init_chroot system. But, it is sometimes useful to have an init_chroot system. So, it would be nice if this can get a proper fix from the source.
>Release-Note:
>Audit-Trail:
>Unformatted: