kern/121566: ethernet iface should be brought up when booting from a mfs_root over nfs

[Robert Schulze]

>Number:         121566
>Category:       kern
>Synopsis:       ethernet iface should be brought up when booting from a mfs_root over nfs
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Mon Mar 10 15:30:00 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator:     Robert Schulze
>Release:        6.2/7.0
>Organization:
bytecamp
>Environment:
FreeBSD freebsd.localdomain 6.2-RELEASE-p7 FreeBSD 6.2-RELEASE-p7 #0: Thu Aug 16 16:45:18 CEST 2007     root at freebsd.localdomain:/usr/obj/usr/src/sys/GENERIC  i386

>Description:
When booting a diskless client through a NFS-root, the code in /usr/src/sys/nfsclient/nfs_vfsops.c fires up an interface with the data from the previous DHCP-request, so it can mount the nfs-share.

When booting the same diskless client through a NFS-shared root-RAM-disk, these settings do not become applied. The functionality of /etc/rc.initdiskless is then obviously broken, because it can't get the right templates to process and can't mount anything (see diskless_remount) from a NFS-server.


>How-To-Repeat:

>Fix:
Maybe the code which initializes the interface with the help of the DHCP-Parameters should be issued by vfs_mountroot_try() before mounting anything else.

Or one could copy the code to /dev/md/md.c and bring out a kernel-option to en/disable this code, when using a MD_ROOT.

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