Comment 13 for bug 381300

Yesterday I was copying (really trying to copy)
78 GB of data from a disk to another one.

Source:
Caviar WD2000BB-22GUA0, a 200GB PATA disk.
USB2.0 to IDE adapter: EBL35U2
ext2 partition...

Dest:
my internal WDC WD3200BEVT-22ZCT0.
ext3 partition...

The system become slow as the copy start,
as usually since I was not using my patched
kernel but the "stock" 2.6.30-9-generic.

But near the end something happened:

[ 810.659068] BUG: unable to handle kernel paging request at 018ca000
[ 810.659079] IP: [<c02f07f5>] __percpu_counter_add+0x25/0xb0
[ 810.659095] *pde = 00000000
[ 810.659101] Oops: 0000 [#1] SMP
[ 810.659108] last sysfs file: /sys/devices/pci0000:00/0000:00:1c.1/0000:04:00.0/rfkill/rfkill0/state
[ 810.659114] Modules linked in: usb_storage binfmt_misc bridge stp bnep vmnet ppdev parport_pc vmblock vmci vmmon lp parport snd_hda_codec_si3054 snd_hda_codec_realtek joydev snd_hda_intel snd_hda_codec arc4 ecb snd_pcm_oss snd_mixer_oss mmc_block snd_pcm iwl3945 iwlcore snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer mac80211 pcmcia snd_seq_device iTCO_wdt iTCO_vendor_support psmouse snd soundcore snd_page_alloc sdhci_pci sdhci btusb cfg80211 serio_raw pcspkr yenta_socket rsrc_nonstatic pcmcia_core led_class usbhid sky2 raid10 raid456 raid6_pq async_xor async_memcpy async_tx xor raid1 raid0 multipath linear i915 drm i2c_algo_bit video output intel_agp agpgart fbcon tileblit font bitblit softcursor
[ 810.659248]
[ 810.659255] Pid: 6126, comm: umount Not tainted (2.6.30-9-generic #10-Ubuntu) AMILO Pro Edition V3505
[ 810.659261] EIP: 0060:[<c02f07f5>] EFLAGS: 00010006 CPU: 0
[ 810.659268] EIP is at __percpu_counter_add+0x25/0xb0
[ 810.659273] EAX: 00000000 EBX: f6974b7c ECX: 00000000 EDX: 00000001
[ 810.659278] ESI: 00000000 EDI: 018ca000 EBP: f3c0bea0 ESP: f3c0be80
[ 810.659283] DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 810.659289] Process umount (pid: 6126, ti=f3c0a000 task=f52a98e0 task.ti=f3c0a000)
[ 810.659294] Stack:
[ 810.659297] f673eff0 c07cbee0 f3c0be90 f6e6893c f6974b7c f6e6893c 00000000 f6e6893c
[ 810.659312] f3c0beb0 c01a218a 00000010 c1716200 f3c0bec8 c01ee2e0 f6e6894c c1716200
[ 810.659327] f4010000 f53b8c14 f3c0bed4 c01ee3a4 f53b8c00 f3c0bef4 c026f84d c0150770
[ 810.659343] Call Trace:
[ 810.659348] [<c01a218a>] ? account_page_dirtied+0x4a/0x80
[ 810.659358] [<c01ee2e0>] ? __set_page_dirty+0x40/0xb0
[ 810.659368] [<c01ee3a4>] ? mark_buffer_dirty+0x54/0x90
[ 810.659377] [<c026f84d>] ? journal_update_superblock+0x6d/0xd0
[ 810.659387] [<c0150770>] ? autoremove_wake_function+0x0/0x50
[ 810.659397] [<c026fcfb>] ? journal_destroy+0xeb/0x110
[ 810.659406] [<c022fa24>] ? ext3_put_super+0x24/0x230
[ 810.659414] [<c01dff86>] ? invalidate_inodes+0xf6/0x120
[ 810.659422] [<c0546b4d>] ? lock_kernel+0x2d/0x50
[ 810.659433] [<c01ceb8a>] ? generic_shutdown_super+0x6a/0x110
[ 810.659441] [<c01cec55>] ? kill_block_super+0x25/0x40
[ 810.659448] [<c02093f0>] ? vfs_quota_off+0x0/0x20
[ 810.659456] [<c01cf1cf>] ? deactivate_super+0x5f/0x80
[ 810.659464] [<c01e373c>] ? mntput_no_expire+0xec/0x130
[ 810.659472] [<c01e3ce4>] ? sys_umount+0x44/0x90
[ 810.659479] [<c01033ec>] ? syscall_call+0x7/0xb
[ 810.659488] Code: bc 27 00 00 00 00 55 89 e5 83 ec 20 89 45 f0 89 5d f4 8b 5d f0 89 75 f8 64 a1 ac 74 7c c0 89 7d fc 8b 7b 14 03 3c 85 60 ce 73 c0 <8b> 07 89 c3 89 c6 8b 45 08 c1 fe 1f 01 d3 11 ce 89 c2 c1 fa 1f
[ 810.659577] EIP: [<c02f07f5>] __percpu_counter_add+0x25/0xb0 SS:ESP 0068:f3c0be80
[ 810.659588] CR2: 00000000018ca000
[ 810.659594] ---[ end trace 1e6bf7fdf9a0d5dd ]---
[ 810.659598] ------------[ cut here ]------------
[ 810.659607] WARNING: at /build/buildd/linux-2.6.30/kernel/exit.c:896 do_exit+0x2f5/0x300()
[ 810.659612] Hardware name: AMILO Pro Edition V3505
[ 810.659616] Modules linked in: usb_storage binfmt_misc bridge stp bnep vmnet ppdev parport_pc vmblock vmci vmmon lp parport snd_hda_codec_si3054 snd_hda_codec_realtek joydev snd_hda_intel snd_hda_codec arc4 ecb snd_pcm_oss snd_mixer_oss mmc_block snd_pcm iwl3945 iwlcore snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer mac80211 pcmcia snd_seq_device iTCO_wdt iTCO_vendor_support psmouse snd soundcore snd_page_alloc sdhci_pci sdhci btusb cfg80211 serio_raw pcspkr yenta_socket rsrc_nonstatic pcmcia_core led_class usbhid sky2 raid10 raid456 raid6_pq async_xor async_memcpy async_tx xor raid1 raid0 multipath linear i915 drm i2c_algo_bit video output intel_agp agpgart fbcon tileblit font bitblit softcursor
[ 810.659753] Pid: 6126, comm: umount Tainted: G D 2.6.30-9-generic #10-Ubuntu
[ 810.659758] Call Trace:
[ 810.659765] [<c013f165>] ? do_exit+0x2f5/0x300
[ 810.659773] [<c013b28c>] warn_slowpath_common+0x6c/0xc0
[ 810.659781] [<c013f165>] ? do_exit+0x2f5/0x300
[ 810.659788] [<c013b2f5>] warn_slowpath_null+0x15/0x20
[ 810.659795] [<c013f165>] do_exit+0x2f5/0x300
[ 810.659802] [<c0544370>] ? printk+0x18/0x20
[ 810.659809] [<c013b1bf>] ? oops_exit+0x2f/0x40
[ 810.659817] [<c05477b8>] oops_end+0xc8/0xd0
[ 810.659825] [<c01231f6>] no_context+0xb6/0xd0
[ 810.659833] [<c0123250>] __bad_area_nosemaphore+0x40/0x190
[ 810.659841] [<c026ae1c>] ? journal_stop+0x13c/0x2a0
[ 810.659849] [<c019a0c5>] ? find_get_pages_tag+0x35/0x120
[ 810.659857] [<c02e507a>] ? rb_insert_color+0xca/0x100
[ 810.659866] [<c01233fb>] bad_area+0x3b/0x50
[ 810.659872] [<c0548e55>] do_page_fault+0x285/0x2f0
[ 810.659879] [<c0548bd0>] ? do_page_fault+0x0/0x2f0
[ 810.659887] [<c0546c2a>] error_code+0x7a/0x80
[ 810.659894] [<c05400d8>] ? early_init_cyrix+0x21/0x3b
[ 810.659901] [<c02f07f5>] ? __percpu_counter_add+0x25/0xb0
[ 810.659910] [<c01a218a>] account_page_dirtied+0x4a/0x80
[ 810.659917] [<c01ee2e0>] __set_page_dirty+0x40/0xb0
[ 810.659925] [<c01ee3a4>] mark_buffer_dirty+0x54/0x90
[ 810.659933] [<c026f84d>] journal_update_superblock+0x6d/0xd0
[ 810.659941] [<c0150770>] ? autoremove_wake_function+0x0/0x50
[ 810.659949] [<c026fcfb>] journal_destroy+0xeb/0x110
[ 810.659956] [<c022fa24>] ext3_put_super+0x24/0x230
[ 810.659963] [<c01dff86>] ? invalidate_inodes+0xf6/0x120
[ 810.659971] [<c0546b4d>] ? lock_kernel+0x2d/0x50
[ 810.659978] [<c01ceb8a>] generic_shutdown_super+0x6a/0x110
[ 810.659984] [<c01cec55>] kill_block_super+0x25/0x40
[ 810.659991] [<c02093f0>] ? vfs_quota_off+0x0/0x20
[ 810.659998] [<c01cf1cf>] deactivate_super+0x5f/0x80
[ 810.660006] [<c01e373c>] mntput_no_expire+0xec/0x130
[ 810.660013] [<c01e3ce4>] sys_umount+0x44/0x90
[ 810.660017] [<c01033ec>] syscall_call+0x7/0xb
[ 810.660017] ---[ end trace 1e6bf7fdf9a0d5de ]---

sync never exit and I was forced to poweroff my system
holding the power button since shutdown never end...

What's happened?