------------[ cut here ]------------
WARNING: at /build/buildd/linux-2.6.38/fs/buffer.c:1151 mark_buffer_dirty+0x87/0xa0()
Hardware name: HP ProBook 4720s
Modules linked in: nls_utf8 udf crc_itu_t nls_iso8859_1 nls_cp437 vfat fat usb_storage uas cryptd aes_x86_64 aes_generic binfmt_misc rfcomm sco bnep l2cap vboxnetadp vboxnetflt vboxdrv parport_pc ppdev snd_hda_codec_hdmi snd_hda_codec_idt snd_hda_intel snd_hda_codec snd_hwdep snd_pcm uvcvideo btusb bluetooth videodev v4l2_compat_ioctl32 snd_seq_midi joydev snd_rawmidi hp_wmi sparse_keymap snd_seq_midi_event snd_seq snd_timer fglrx(P) snd_seq_device snd intel_ips soundcore psmouse serio_raw snd_page_alloc video hp_accel lis3lv02d input_polldev lp parport usbhid hid ahci libahci r8169
Pid: 16037, comm: umount Tainted: P            2.6.38-8-generic #41-Ubuntu
Call Trace:
 [<ffffffff81065cef>] ? warn_slowpath_common+0x7f/0xc0
 [<ffffffff81065d4a>] ? warn_slowpath_null+0x1a/0x20
 [<ffffffff81192167>] ? mark_buffer_dirty+0x87/0xa0
 [<ffffffffa06e4bb8>] ? udf_close_lvid.clone.12+0xe8/0x120 [udf]
 [<ffffffffa06e6388>] ? udf_put_super+0x88/0x100 [udf]
 [<ffffffff81166c42>] ? generic_shutdown_super+0x72/0x100
 [<ffffffff81166d01>] ? kill_block_super+0x31/0x80
 [<ffffffff811671d5>] ? deactivate_locked_super+0x45/0x70
 [<ffffffff81167e5a>] ? deactivate_super+0x4a/0x70
 [<ffffffff81183254>] ? mntput_no_expire+0xa4/0xf0
 [<ffffffff811842e0>] ? sys_umount+0x60/0xd0
 [<ffffffff8100c002>] ? system_call_fastpath+0x16/0x1b
---[ end trace 9c0918e71f6d7021 ]---