>Number:         29881
>Category:       kern
>Synopsis:       umount stale NFS volume blocks deadly
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 04 18:29:00 +0000 2005
>Originator:     Denis Lagno
>Release:        NetBSD 2.99.16
>Organization:
>Environment:
System: NetBSD chup.gado 2.99.16 NetBSD 2.99.16 (CHUP) #0: Sun Mar 13 11:50:19 MSK 2005 dina@chup.gado:/flam/volatile/worksrc/netbsd-current/src/sys/arch/i386/compile/CHUP i386
Architecture: i386
Machine: i386
>Description:
I mount NFS volume, then for some reason I lose the network.  Then umount this volume just blocks.
So if I reboot, it stops in "Unmounting file systems" and no progress ever seen.

Second similar problem: if I mount NFS volume, then at server side exported directory
gone.  Then mounted volume cannot be umounted.  umount -f gives error:

# umount -fv /flam/stuffy
/stuffy: unmount from /flam/stuffy
umount: /flam/stuffy: Invalid argument
>How-To-Repeat:
Mount NFS volume, lose connection to NFS server and try to reboot, or simply umount volume.
>Fix:
N/A