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: [] __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:[] 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] [] ? account_page_dirtied+0x4a/0x80 [ 810.659358] [] ? __set_page_dirty+0x40/0xb0 [ 810.659368] [] ? mark_buffer_dirty+0x54/0x90 [ 810.659377] [] ? journal_update_superblock+0x6d/0xd0 [ 810.659387] [] ? autoremove_wake_function+0x0/0x50 [ 810.659397] [] ? journal_destroy+0xeb/0x110 [ 810.659406] [] ? ext3_put_super+0x24/0x230 [ 810.659414] [] ? invalidate_inodes+0xf6/0x120 [ 810.659422] [] ? lock_kernel+0x2d/0x50 [ 810.659433] [] ? generic_shutdown_super+0x6a/0x110 [ 810.659441] [] ? kill_block_super+0x25/0x40 [ 810.659448] [] ? vfs_quota_off+0x0/0x20 [ 810.659456] [] ? deactivate_super+0x5f/0x80 [ 810.659464] [] ? mntput_no_expire+0xec/0x130 [ 810.659472] [] ? sys_umount+0x44/0x90 [ 810.659479] [] ? 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: [] __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] [] ? do_exit+0x2f5/0x300 [ 810.659773] [] warn_slowpath_common+0x6c/0xc0 [ 810.659781] [] ? do_exit+0x2f5/0x300 [ 810.659788] [] warn_slowpath_null+0x15/0x20 [ 810.659795] [] do_exit+0x2f5/0x300 [ 810.659802] [] ? printk+0x18/0x20 [ 810.659809] [] ? oops_exit+0x2f/0x40 [ 810.659817] [] oops_end+0xc8/0xd0 [ 810.659825] [] no_context+0xb6/0xd0 [ 810.659833] [] __bad_area_nosemaphore+0x40/0x190 [ 810.659841] [] ? journal_stop+0x13c/0x2a0 [ 810.659849] [] ? find_get_pages_tag+0x35/0x120 [ 810.659857] [] ? rb_insert_color+0xca/0x100 [ 810.659866] [] bad_area+0x3b/0x50 [ 810.659872] [] do_page_fault+0x285/0x2f0 [ 810.659879] [] ? do_page_fault+0x0/0x2f0 [ 810.659887] [] error_code+0x7a/0x80 [ 810.659894] [] ? early_init_cyrix+0x21/0x3b [ 810.659901] [] ? __percpu_counter_add+0x25/0xb0 [ 810.659910] [] account_page_dirtied+0x4a/0x80 [ 810.659917] [] __set_page_dirty+0x40/0xb0 [ 810.659925] [] mark_buffer_dirty+0x54/0x90 [ 810.659933] [] journal_update_superblock+0x6d/0xd0 [ 810.659941] [] ? autoremove_wake_function+0x0/0x50 [ 810.659949] [] journal_destroy+0xeb/0x110 [ 810.659956] [] ext3_put_super+0x24/0x230 [ 810.659963] [] ? invalidate_inodes+0xf6/0x120 [ 810.659971] [] ? lock_kernel+0x2d/0x50 [ 810.659978] [] generic_shutdown_super+0x6a/0x110 [ 810.659984] [] kill_block_super+0x25/0x40 [ 810.659991] [] ? vfs_quota_off+0x0/0x20 [ 810.659998] [] deactivate_super+0x5f/0x80 [ 810.660006] [] mntput_no_expire+0xec/0x130 [ 810.660013] [] sys_umount+0x44/0x90 [ 810.660017] [] 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?