i386/131341: error "Bad file descriptor" on the mount point of md-presentation makefs image

[Oleg Ginzburg]

>Number:         131341
>Category:       i386
>Synopsis:       error "Bad file descriptor"  on the mount point of md-presentation makefs image
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Feb 03 13:50:02 UTC 2009
>Closed-Date:
>Last-Modified:
>Originator:     Oleg Ginzburg
>Release:        8-CURRENT amd64, 8-CURRENT i386, 7.1-RELEASE i386 (with makefs(8) from the ports)
>Organization:
Nevosoft
>Environment:
FreeBSD oleg.net.nevosoft.ru 8.0-CURRENT FreeBSD 8.0-CURRENT #2 r187912M: Fri Jan 30 13:17:19 MSK 2009     root at oleg.net.nevosoft.ru:/usr/obj/usr/src/sys/o20090103  i386
>Description:
"df <mountpoint>"
return "Bad file descriptor" when mount point is md-based layer presentation of image and image created with sector-size > 512 (default):
--
mount /mnt
mount: /mnt: unknown special file or file system
--

With "df" without arguments pictures is correct
--
df |grep mnt
/dev/md0           5079        1      4672     0%    /mnt
--

>How-To-Repeat:
1) mkdir /tmp/empty && makefs -S 1024 -s 5m /tmp/newimage /tmp/empty
2) mount /dev/`mdconfig -a -t vnode -f /tmp/newimage` /mnt
3) df /mnt
4) df

(where /mnt is free point for mounting)
>Fix:


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