kern/60430: Soft Updates on root filesystem cause panic in 5.2-RC1

[Brian Knoll]

>Number:         60430
>Category:       kern
>Synopsis:       Soft Updates on root filesystem cause panic in 5.2-RC1
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Dec 20 12:30:25 PST 2003
>Closed-Date:
>Last-Modified:
>Originator:     Brian Knoll
>Release:        5.2-RC1
>Organization:
>Environment:
FreeBSD local.network.com 5.2-RC1 FreeBSD 5.2-RC1 #0: Sun Dec  7 22:15:14 GMT 2003     root at wv1u.btc.adaptec.com:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
Problem is observed during the installation process of FreeBSD 5.2-RC1.  When the root partition is configured to use Soft-Updates during the install, the kernel will panic during the install once the installation reaches the point where the root filesystem is being populated.  This problem does not occur in FreeBSD 4.9.  Size of the root filesystem doesn't seem to matter, at least in my experiments.  I have tried root filesystems ranging from 256MB to 1024MB and in no case did I prevent the panic from occurring as long as Soft-Updates were enabled on the root filesystem.  The problem appears to be 100% reproducible as near as I can tell.
>How-To-Repeat:
Start an installation of FreeBSD 5.2-RC1.  In the disklabel editor, select Soft-Updates for the root filesystem (this is the default for other UFS2 filesystems but not for the root filesystem) by pressing "S" while the root filesystem is selected.  Proceed with the installation.  At the point where the root filesystem is being populated with files, the kernel will panic.
>Fix:

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