i386/151330: will unshare all zfs filesystem after execute a "zfs clone"

Sat Oct 9 05:30:02 UTC 2010

>Number:         151330
>Category:       i386
>Synopsis:       will unshare all zfs filesystem after execute a "zfs clone"
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Oct 09 05:30:01 UTC 2010
>Closed-Date:
>Last-Modified:
>Originator:     &#38472;&#20809;&#20581;
>Release:        8.1
>Organization:
&#21830;&#21697;&#25151;
>Environment:
FreeBSD FBSD-Z 8.1-RELEASE FreeBSD 8.1-RELEASE #0: Mon Jul 19 02:55:53 UTC 2010     root at almeida.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC  i386
>Description:
i am using FreeBSD ZFS+NFS as filesystem server, support nfs filesystem for other organization, i can successfully to create zpool and create zfs filesystem, set sherenfs=on to share nfs to another machine.

but today when i execute "zfs clone za/za2 at empty za/za2/empty", then all nfs client got error:
df: `/backup': Input/output error

i ran "showmount -e" at freebsd server, i found nothing display, before clone it show all zfs filesystem what can be nfs mount at client.
>How-To-Repeat:
1. create a zpool name za1
2. zfs set sharenfs=on za1
3. make sure all nfs process has been started.execute "showmount -e" will display /za1 can be nfs mount.
4. go to another machine which install redhat linux 5.3.
5. mount nfs using oralce recommendation option:
mount -o rw,bg,hard,rsize=32768,wsize=32768,vers=3,nointr,timeo=600,tcp 192.168.56.130:/za1 /backup
6. at freebsd server, execute "zfs snapshot za1 at empty", then execute "zfs clone za1 at empty za1/empty", after that, execute "showmount -e", nothing display.
7. go to client machine, execute "df -k" will get Input/output error.
>Fix:
at freebsd: ps aux|grep mountd
kill mountd session, and restart mountd, then execute "showmount -e", all nfs share point will display.

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