Unusual mount behaviour for pktcdvd0

Hi,

I am attempting to use packet-writing on CD-RW media with Gentoo 
GNU/Linux. The kernel is 2.6.10 and has the packet-writing patch already 
applied and I have enabled packet-writing and UDF support.

I did need to upgrade my udev from 045 to 050 to fix a wait_for_sysfs 
error that was logged to syslog when attempting to access pktcdvd0. Also 
I had to modify my udev rules and permissions to relocate the control 
and packet device nodes into /dev/pktcdvd.

The situation I have is that I can use cdrwtool to create a UDF 
filesystem on CD-RW without any sign of error. I can then assign the 
packet device using pktsetup and mount and unmount the packet device r/w 
as many times as I like.

Once I have de-assigned the packet device, a subsequent attempt to 
assign it again works but I can then only mount the packet device in r/o 
mode. Mount reports it "can't read superblock" for an attempt to r/w 
mount the packet device and syslog reports a "No track?" error.

It is possible to mount the device r/o and then remount it r/w though.

I've never been able to create a UDF filesystem directly using mkudffs, 
which always reports "trying to change type of multiple extents".

Has anyone observed a similar scenario and been able to find a solution 
that permits r/w mounting after de-assignment/re-assignment of the 
packet device?

For your information:
MSI DR8-A2 DVD/CD Writer
TDK CD-RW 700 Media (4x)
gentoo-dev-sources-2.6.10-r6 kernel
udftools-1.0.0-r4
udev-050

udev permissions.d/50-udev.permissions addition:
pktcdvd/*:root:cdrw:0660

udev rules.d/50-udev.rules addition:
KERNEL="pktcdvd",       NAME="pktcdvd/control"
KERNEL="pktcdvd[0-9]*", NAME="pktcdvd/pktcdvd%n"

Commands used:
cdrwtool -d /dev/hdc -q -t 4
pktsetup pktcdvd0 /dev/hdc
mount -t udf -o rw,noatime /dev/pktcdvd/pktcdvd0 /mnt/cdrom <-- OK
umount /mnt/cdrom
pktsetup -d pktcdvd0
pktsetup pktcdvd0 /dev/hdc
mount -t udf -o rw,noatime /dev/pktcdvd/pktcdvd0 /mnt/cdrom <-- FAILS

Regards,
Neil Darlow

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