Hi there... This is something weird that happened. I was having problems with having a btrfs root, so I copied the root filesystem to an external USB hard drive. Then I rebooted the computer from a CD-ROM, and re-created my root partition with ext4. Then I mounted the USB hard drive ( also btrfs ) to a different directory, and proceeded in copying my root back. This went well, and then I chrooted to the new root, and ran lilo to update my bootblock. Then I exited the chroot, and wanted to unmount the usb disk. This hung up my tty solid. I was only reading from the USB device, so I figured that since I was not writing to the usb device, I could unplug it. This gave me a kernel oops. So, I hard-rebooted, and booted into my newly created root. Now the usb drive does not want to mount anymore, with the following message in dmesg: usb 7-5.3: new high speed USB device using ehci_hcd and address 7 usb 7-5.3: New USB device found, idVendor=0bc2, idProduct=5021 usb 7-5.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 usb 7-5.3: Product: FreeAgent GoFlex usb 7-5.3: Manufacturer: Seagate usb 7-5.3: SerialNumber: NA050N36 scsi9 : usb-storage 7-5.3:1.0 scsi 9:0:0:0: Direct-Access Seagate FreeAgent GoFlex 0148 PQ: 0 ANSI: 4 sd 9:0:0:0: Attached scsi generic sg9 type 0 sd 9:0:0:0: [sdi] 1953525167 512-byte logical blocks: (1.00 TB/931 GiB) sd 9:0:0:0: [sdi] Write Protect is off sd 9:0:0:0: [sdi] Mode Sense: 1c 00 00 00 sd 9:0:0:0: [sdi] Assuming drive cache: write through sd 9:0:0:0: [sdi] Assuming drive cache: write through sdi: sdi1 sd 9:0:0:0: [sdi] Assuming drive cache: write through sd 9:0:0:0: [sdi] Attached SCSI disk device label TeraByte1 devid 1 transid 6339 /dev/sdi1 verify_parent_transid: 28 callbacks suppressed parent transid verify failed on 611018129408 wanted 6339 found 6619 parent transid verify failed on 611018129408 wanted 6339 found 6619 parent transid verify failed on 611018129408 wanted 6339 found 6619 BUG: unable to handle kernel NULL pointer dereference at 00000000000000a8 IP: [<ffffffff81031925>] __ticket_spin_lock+0x5/0x20 PGD 224526067 PUD 224525067 PMD 0 Oops: 0002 [#1] SMP last sysfs file: /sys/devices/virtual/bdi/btrfs-3/uevent CPU 0 Modules linked in: snd_seq_dummy snd_seq_oss snd_seq_midi_event snd_seq ipv6 snd_pcm_oss snd_mixer_oss binfmt_misc ext2 btrfs zlib_deflate crc32c libcrc32c ext4 mbcache jbd2 crc32 crc16 af_packet scsi_wait_scan fuse dm_mod joydev usbhid hid nvidia(P) usb_storage usb_libusual sg sr_mod sd_mod cdrom crc_t10dif ata_generic pata_acpi pata_jmicron 8250_pnp ohci1394 ieee1394 snd_cmipci gameport snd_opl3_lib snd_pcm snd_hwdep ahci libahci snd_timer libata rtc_cmos evdev firewire_ohci snd_mpu401_uart ehci_hcd 8250 uhci_hcd rtc_core snd_rawmidi firewire_core snd_seq_device snd i2c_i801 iTCO_wdt rtc_lib usbcore crc_itu_t serial_core i2c_core floppy iTCO_vendor_support button processor soundcore snd_page_alloc pcspkr shpchp psmouse serio_raw e1000e scsi_mod nls_base thermal pci_hotplug intel_agp configfs [last unloaded: cfbfillrect] Pid: 1174, comm: mount Tainted: P 2.6.36.1 #1 DG35EC/ RIP: 0010:[<ffffffff81031925>] [<ffffffff81031925>] __ticket_spin_lock+0x5/0x20 RSP: 0018:ffff88022454bb58 EFLAGS: 00010246 RAX: 0000000000000100 RBX: ffff880224556210 RCX: ffff880224554000 RDX: ffff880224554168 RSI: ffff880224554140 RDI: 00000000000000a8 RBP: ffff880224554000 R08: 0000160000000000 R09: 0000000000000000 R10: 0000000000000010 R11: 0000000000000008 R12: 0000000000000000 R13: 00000000000000a8 R14: 0000000000000000 R15: 0000000000000004 FS: 00007f9907dbf740(0000) GS:ffff880001800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00000000000000a8 CR3: 0000000224523000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process mount (pid: 1174, threadinfo ffff88022454a000, task ffff8802054c4000) Stack: ffffffff81313335 ffffffffa0df7f3f 0000000000000001 ffff8802245561c8 <0> ffff880222252090 ffff880224556210 ffff880221436800 ffff880221433800 <0> ffff880221437800 ffffffffa0df9618 0000008e68017000 00000000221c03fc Call Trace: [<ffffffff81313335>] ? _raw_spin_lock+0x5/0x10 [<ffffffffa0df7f3f>] ? btrfs_delalloc_release_space+0x59f/0x720 [btrfs] [<ffffffffa0df9618>] ? btrfs_read_block_groups+0x608/0x890 [btrfs] [<ffffffffa0e0abd2>] ? open_ctree+0xfd2/0x1b40 [btrfs] [<ffffffffa0debbde>] ? 0xffffffffa0debbde [<ffffffff81103eb3>] ? vfs_kern_mount+0x83/0x200 [<ffffffff811040a3>] ? do_kern_mount+0x53/0x130 [<ffffffff8111d648>] ? do_mount+0x2f8/0x8a0 [<ffffffff810c840f>] ? memdup_user+0x3f/0x80 [<ffffffff8111dc8a>] ? sys_mount+0x9a/0xf0 [<ffffffff8100aec2>] ? system_call_fastpath+0x16/0x1b Code: ff 0f 1f 44 00 00 48 c7 c2 2e 17 03 81 48 c7 c1 31 17 03 81 e9 dd fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 b8 00 01 00 00 <f0> 66 0f c1 07 38 e0 74 06 f3 90 8a 07 eb f6 c3 66 66 2e 0f 1f RIP [<ffffffff81031925>] __ticket_spin_lock+0x5/0x20 RSP <ffff88022454bb58> CR2: 00000000000000a8 ---[ end trace 136e10b80e427347 ]--- btrfsck also does not repair the drive. Is there any way of getting any of the information off of this disk? -Evert Vorster- This is on kernel 2.6.36.1, by the way. -- http://magnatune.com - Music shared the way it should be. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html