------------[ cut here ]------------
WARNING: at /build/buildd/linux-2.6.38/ubuntu/aufs/plink.c:450 au_plink_put+0x4c/0xa0 [aufs]()
Hardware name: 7465CTO
pseudo-link is not flushed
Modules linked in: aufs binfmt_misc rfcomm sco bnep l2cap parport_pc ppdev snd_hda_codec_conexant snd_hda_intel arc4 snd_hda_codec snd_hwdep snd_pcm thinkpad_acpi snd_seq_midi snd_rawmidi iwlagn snd_seq_midi_event snd_seq iwlcore mac80211 snd_timer snd_seq_device snd cfg80211 tpm_tis tpm lp tpm_bios btusb soundcore bluetooth snd_page_alloc parport psmouse nvram serio_raw sha256_generic cryptd aes_x86_64 aes_generic dm_crypt i915 drm_kms_helper drm ahci libahci i2c_algo_bit video e1000e
Pid: 5778, comm: umount Not tainted 2.6.38-7-generic #39-Ubuntu
Call Trace:
 [<ffffffff8106573f>] ? warn_slowpath_common+0x7f/0xc0
 [<ffffffff81065836>] ? warn_slowpath_fmt+0x46/0x50
 [<ffffffffa03dc6dc>] ? au_plink_put+0x4c/0xa0 [aufs]
 [<ffffffffa03bed0d>] ? aufs_kill_sb+0x13d/0x150 [aufs]
 [<ffffffff81150aae>] ? spin_unlock+0xe/0x20
 [<ffffffff81154f8b>] ? __slab_free+0xcb/0x150
 [<ffffffff81165f55>] ? deactivate_locked_super+0x45/0x70
 [<ffffffff81166baa>] ? deactivate_super+0x4a/0x70
 [<ffffffff81181f84>] ? mntput_no_expire+0xa4/0xf0
 [<ffffffff81183010>] ? sys_umount+0x60/0xd0
 [<ffffffff8100c002>] ? system_call_fastpath+0x16/0x1b
---[ end trace b14573f21f17abaf ]---