Hello 

Same kernel oops when removing a bootable USB flash drive. I tried to reproduce the problem by removing the key, but I couldn't

Here is my dmesg :
[182350.770035] usb 2-3: USB disconnect, address 11
[182350.777727] ------------[ cut here ]------------
[182350.777750] WARNING: at /build/buildd/linux-2.6.31/fs/buffer.c:1152 mark_buffer_dirty+0x70/0x90()
[182350.777757] Hardware name: Latitude D630                   
[182350.777763] Modules linked in: ums_cypress usb_storage tun nls_utf8 cifs nfs lockd nfs_acl auth_rpcgss sunrpc binfmt_misc ppdev ipt_MASQUERADE iptable_nat nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp kvm_intel kvm autofs4 vfat fat sbp2 lp parport snd_hda_codec_idt snd_hda_intel snd_hda_codec b43 snd_hwdep snd_pcm_oss snd_mixer_oss i915 mac80211 snd_pcm drm snd_timer dell_wmi pcmcia i2c_algo_bit snd dell_laptop joydev cfg80211 soundcore iTCO_wdt dcdbas yenta_socket led_class intel_agp agpgart iTCO_vendor_support snd_page_alloc rsrc_nonstatic pcmcia_core pcspkr psmouse serio_raw video output usbhid ohci1394 ieee1394 ssb tg3 fbcon tileblit font bitblit softcursor dm_raid45 xor
[182350.777942] Pid: 26, comm: khubd Not tainted 2.6.31-20-generic #58-Ubuntu
[182350.777948] Call Trace:
[182350.777965]  [<c01450ad>] warn_slowpath_common+0x6d/0xa0
[182350.777975]  [<c0209ce0>] ? mark_buffer_dirty+0x70/0x90
[182350.777983]  [<c0209ce0>] ? mark_buffer_dirty+0x70/0x90
[182350.777992]  [<c01450f5>] warn_slowpath_null+0x15/0x20
[182350.778000]  [<c0209ce0>] mark_buffer_dirty+0x70/0x90
[182350.778013]  [<c02597f3>] ext2_sync_fs+0x33/0x90
[182350.778021]  [<c0207bc9>] __sync_filesystem+0x39/0x60
[182350.778030]  [<c0207d91>] sync_filesystem+0x31/0x50
[182350.778038]  [<c020fb5f>] fsync_bdev+0x1f/0x50
[182350.778049]  [<c030cb0f>] invalidate_partition+0x1f/0x40
[182350.778060]  [<c0233b7d>] del_gendisk+0x2d/0x110
[182350.778071]  [<c03c5990>] sd_remove+0x40/0x80
[182350.778082]  [<c03a664e>] __device_release_driver+0x3e/0x90
[182350.778090]  [<c03a6760>] device_release_driver+0x20/0x40
[182350.778099]  [<c03a5aa3>] bus_remove_device+0x73/0x90
[182350.778108]  [<c03a420f>] device_del+0xef/0x150
[182350.778117]  [<c03c19d7>] __scsi_remove_device+0x47/0x80
[182350.778126]  [<c03be6af>] scsi_forget_host+0x5f/0x70
[182350.778136]  [<c03b74d8>] scsi_remove_host+0x58/0xe0
[182350.778163]  [<fb0f5e7b>] quiesce_and_remove_host+0x5b/0xa0 [usb_storage]
[182350.778182]  [<fb0f5f6e>] usb_stor_disconnect+0xe/0x20 [usb_storage]
[182350.778194]  [<c0418741>] usb_unbind_interface+0x41/0x120
[182350.778203]  [<c03a664e>] __device_release_driver+0x3e/0x90
[182350.778212]  [<c03a6760>] device_release_driver+0x20/0x40
[182350.778221]  [<c03a5aa3>] bus_remove_device+0x73/0x90
[182350.778230]  [<c03a420f>] device_del+0xef/0x150
[182350.778238]  [<c041569d>] usb_disable_device+0x7d/0xf0
[182350.778247]  [<c04102ee>] usb_disconnect+0x9e/0x110
[182350.778256]  [<c04106a3>] hub_port_connect_change+0x83/0x830
[182350.778265]  [<c0416370>] ? usb_control_msg+0xd0/0x120
[182350.778274]  [<c040e4eb>] ? clear_port_feature+0x4b/0x60
[182350.778282]  [<c0411f05>] hub_events+0x1f5/0x500
[182350.778292]  [<c0571d7c>] ? schedule+0x40c/0x730
[182350.778303]  [<c015c2da>] ? finish_wait+0x4a/0x70
[182350.778311]  [<c0412210>] ? hub_thread+0x0/0x150
[182350.778319]  [<c0412245>] hub_thread+0x35/0x150
[182350.778328]  [<c015c180>] ? autoremove_wake_function+0x0/0x40
[182350.778336]  [<c015be8c>] kthread+0x7c/0x90
[182350.778344]  [<c015be10>] ? kthread+0x0/0x90
[182350.778353]  [<c0104047>] kernel_thread_helper+0x7/0x10
[182350.778359] ---[ end trace 833d4dff225ab79f ]---