linux-kernel - DVD-RAM problems (low priority)

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Message-ID: <AANLkTimrfgftSTC9lqRmmTWIjXkHoZd4TIJGk0KVgqm3@mail.gmail.com>
Date:	Sat, 3 Jul 2010 12:37:43 -0400
From:	trouble daemon <troubledaemon@...il.com>
To:	linux-kernel@...r.kernel.org
Subject: DVD-RAM problems (low priority)

Hello again,

I am currently experiencing some problems with DVD-RAM media under
ubuntu lucid lynx, and I was wondering if you might recognize some of
the behaviour as being normal, or a bug.

What I do is insert a disk, then issue `mkudffs --media-type=dvdram
--utf8 /dev/sr0` and then `mount /media/cdrom0`. All seems to go well
and I get an entry that shows up as:

 /dev/sr0 on /media/cdrom0 type udf (rw,nosuid,nodev,utf8,user=dan)

At this point, I tried a simple copy of the linux git repository
(~850mb), but 3 hours later it is still copying. With other small test
writes, I also noticed that when I issue a umount, the command blocks
for maybe 10 seconds, then returns, yet the drive light appears to
continue to be writting for at least 5 minutes past the umount. At
that point it starts spiking a nice'd load or something, on one of the
cores of my system to 100% and stays there until I eject the disk. The
problem is that ejecting the disk seems to mess up the copy as well.
And even after I eject, the load stays at 100% on one core.

As for the drive, it is:

wodim: Overview of accessible drives (1 found) :
-------------------------------------------------------------------------
 0  dev='/dev/scd0'     rwrw-- : 'HL-DT-ST' 'DVDRAM GH22NS50'
-------------------------------------------------------------------------

Current kernel: Linux wks 2.6.32-23-generic #37-Ubuntu SMP Fri Jun 11
08:03:28 UTC 2010 x86_64 GNU/Linux

It seems that even after I umount, a program called
gvfs-gdu-volume-monitor starts going nuts writting to the disc and
pegging one of the cores, followed by udevd using 100% after an
eject+reinsert. Correct me if I am wrong, but absolutely nothing
should be writting to any device after a umount, no?

I should note that with very small tests of say 2-3mb, I can usually
get a successful write, but there still is the issue of the system still
writting in secret to the device after umount even then. Could this be
gvfs related?

Anyways, until I can track down exactly what might be interfering with
the writes, I would love to hear back on if I am just doing something
incorrectly. Please CC me email address, as I do not subscribe to
the LKML itself. Any help would be appreciated. Thanks!

PS - 	linux_udf@...sjro.fc.hp.com as listed in the
Documentation/filesystems/udf.txt file, bounces

troubled
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