Re: Unable to mount/restore partition after eSATA fail

[Stefan Harwarth <mailingliste@harwarth.de>]

Hi cwillu,

thanks for the quick reply. I didn't realize that my debian 6 was 
shipping such an old btrfs/kernel package - though I should have known 
better :(

Anyways I already tried to recover my files with an Ubuntu 12.04 (Kernel 
3.2) and following your recommendation, I upgraded to 3.5 and tried 
btrfsck, btrfs-restore and btrfs-find-root on /dev/sdb as well as the 
partition /dev/sdb1 but I only got "no btrfs filesystem" and "could not 
open root, trying backup super" (for btrfs-restore).

I haven't tried -o recovery yet, but it looks to me like there's no 
starting point at all for the tools (which brings me back to the 6.4meg 
of NULL-bytes at the start of the partition).

So is there any chance on recovering FS information, from what I read in 
wikipedia btrfs stores some copies of important FS metadata throughout 
the partition.

Regards, Stefan

Am 24.08.2012 23:00, schrieb cwillu:
> You _need_ to use a recent kernel; 2.6.32 is nearly 3 years old, which
> is prehistoric in btrfs terms.
>
> It may Just Work in 3.5; if it doesn't, try 3.5 with -o recovery.
>
> On Fri, Aug 24, 2012 at 2:30 PM, Stefan Harwarth
> <mailingliste@harwarth.de> wrote:
>> Hi btrfs people,
>>
>> I've been using btrfs for 2 months or so. After an incident where apparently
>> my eSATA connection got lost (according to syslog, see end of mail), the
>> partition cannot be mounted anymore. Even worse, all btrfs tools report
>> there is no btrfs filesystem on the partition (and parted/gdisk/... all show
>> no filesystem indication at all for the partition). I have included the
>> syslog excerpts from when the error happened and the syslog when I first
>> retried to mount the volume.
>>
>> I took a look at the raw data in the partition (dd if=/dev/sdb1 ...) and -
>> which is not a good sign, I guess - the first non-null Bytes are around 6,4
>> MB from the start of the partition, and they do not look like file system
>> information but more like a windows ISO which was stored on the drive. The
>> HDD does not report any damages in the SMART-report.
>>
>> Is there any chance to get the data back from the drive? It won't kill me if
>> it's lost, but recovery would save me a hell lot of work.
>>
>> Thanks in advance,
>>
>> Stefan
>>
>> First syslog when the error occured:
>>
>> Aug  9 05:30:26 debian kernel: [23735.292560] sda: detected capacity change
>> from 2000398934016 to 0
>> Aug  9 05:31:50 debian kernel: [23819.504883] lost page write due to I/O
>> error on sda1
>> Aug  9 05:31:50 debian kernel: [23819.504944] lost page write due to I/O
>> error on sda1
>> Aug  9 05:31:50 debian kernel: [23819.505007] end_request: I/O error, dev
>> sda, sector 536872960
>> Aug  9 05:31:50 debian kernel: [23819.505049] lost page write due to I/O
>> error on sda1
>> Aug  9 05:31:50 debian kernel: [23819.505058] btrfs: 1 errors while writing
>> supers
>> Aug  9 05:31:50 debian kernel: [23819.505128] ------------[ cut here
>> ]------------
>> Aug  9 05:31:50 debian kernel: [23819.505164] kernel BUG at
>> /build/buildd-linux-2.6_2.6.32-45-i386-yQfQSv/linux-2.6-2.6.32/debian/build/source_i386_none/fs/btrfs/disk-io.c:2302!
>> Aug  9 05:31:50 debian kernel: [23819.505243] invalid opcode: 0000 [#1] SMP
>> Aug  9 05:31:50 debian kernel: [23819.505281] last sysfs file:
>> /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/PNP0C09:00/PNP0C0A:00/power_supply/BAT0/energy_full
>> Aug  9 05:31:50 debian kernel: [23819.505356] Modules linked in: btrfs
>> zlib_deflate crc32c libcrc32c loop joydev i915 drm_kms_helper pcmcia
>> thinkpad_acpi rfkill drm parport_pc snd_intel8x0 snd_ac97_codec ac97_bus
>> led_class yenta_socket i2c_algo_bit snd_pcm i2c_i801 parport rsrc_nonstatic
>> psmouse serio_raw snd_timer video pcmcia_core nvram pcspkr i2c_core output
>> evdev snd rng_core soundcore battery ac processor button snd_page_alloc ext3
>> jbd mbcache ata_generic sd_mod crc_t10dif ata_piix uhci_hcd ahci sata_sil24
>> tg3 thermal ehci_hcd usbcore libata scsi_mod libphy thermal_sys nls_base
>> [last unloaded: scsi_wait_scan]
>> Aug  9 05:31:50 debian kernel: [23819.505772]
>> Aug  9 05:31:50 debian kernel: [23819.505803] Pid: 775, comm:
>> btrfs-transacti Not tainted (2.6.32-5-686 #1) 18714AG
>> Aug  9 05:31:50 debian kernel: [23819.505865] EIP: 0060:[<f8a27a8d>] EFLAGS:
>> 00010282 CPU: 0
>> Aug  9 05:31:50 debian kernel: [23819.505935] EIP is at
>> write_all_supers+0x20f/0x21f [btrfs]
>> Aug  9 05:31:50 debian kernel: [23819.505973] EAX: 0000003a EBX: f6f47658
>> ECX: f6773f18 EDX: f8a5e117
>> Aug  9 05:31:50 debian kernel: [23819.506014] ESI: 00000001 EDI: 00000003
>> EBP: f6d22000 ESP: f6773f14
>> Aug  9 05:31:50 debian kernel: [23819.506054]  DS: 007b ES: 007b FS: 00d8
>> GS: 00e0 SS: 0068
>> Aug  9 05:31:50 debian kernel: [23819.506095] Process btrfs-transacti (pid:
>> 775, ti=f6772000 task=f6495980 task.ti=f6772000)
>> Aug  9 05:31:50 debian kernel: [23819.506157] Stack:
>> Aug  9 05:31:50 debian kernel: [23819.506184]  f8a5e117 00000001 00000000
>> f66bd800 f6f47658 f6d22c2f 00000001 00000000
>> Aug  9 05:31:50 debian kernel: [23819.506239] <0> 00000000 f6d22d3a f6d22d4a
>> f6f47600 f6991030 f6d22c2f f6d2375a f66bd800
>> Aug  9 05:31:50 debian kernel: [23819.506316] <0> f8a2a868 f6991030 f6b2d04c
>> 00000003 00000000 00000000 f6b2d064 f6b2d000
>> Aug  9 05:31:50 debian kernel: [23819.506412] Call Trace:
>> Aug  9 05:31:50 debian kernel: [23819.506473]  [<f8a2a868>] ?
>> btrfs_commit_transaction+0x4c0/0x5a1 [btrfs]
>> Aug  9 05:31:50 debian kernel: [23819.506523]  [<c104432e>] ?
>> autoremove_wake_function+0x0/0x2d
>> Aug  9 05:31:50 debian kernel: [23819.506588]  [<f8a26805>] ?
>> transaction_kthread+0x133/0x19e [btrfs]
>> Aug  9 05:31:50 debian kernel: [23819.506634]  [<c1024a6f>] ?
>> complete+0x28/0x36
>> Aug  9 05:31:50 debian kernel: [23819.506696]  [<f8a266d2>] ?
>> transaction_kthread+0x0/0x19e [btrfs]
>> Aug  9 05:31:50 debian kernel: [23819.506739]  [<c10440fc>] ?
>> kthread+0x61/0x66
>> Aug  9 05:31:50 debian kernel: [23819.506777]  [<c104409b>] ?
>> kthread+0x0/0x66
>> Aug  9 05:31:50 debian kernel: [23819.506816]  [<c1003d47>] ?
>> kernel_thread_helper+0x7/0x10
>> Aug  9 05:31:50 debian kernel: [23819.506853] Code: 75 c4 8b 54 24 04 8b 82
>> 14 01 00 00 8b 80 b8 1c 00 00 83 c0 44 e8 3f 6b 84 c8 3b 74 24 14 7e 11 56
>> 68 17 e1 a5 f8 e8 18 5c 84 c8 <0f> 0b 58 5a eb fe 83 c4 28 31 c0 5b 5e 5f 5d
>> c3 89 d0 89 ca e9
>> Aug  9 05:31:50 debian kernel: [23819.507072] EIP: [<f8a27a8d>]
>> write_all_supers+0x20f/0x21f [btrfs] SS:ESP 0068:f6773f14
>> Aug  9 05:31:50 debian kernel: [23819.507474] ---[ end trace
>> 31cd148f196f7433 ]---
>>
>>
>> Second syslog when I first tried to remount the drive:
>>
>> Aug 13 23:59:00 debian kernel: [435848.980197] BUG: unable to handle kernel
>> NULL pointer dereference at 0000001c
>> Aug 13 23:59:00 debian kernel: [435848.980269] IP: [<f8a21d84>]
>> btrfs_print_leaf+0xe/0x765 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.980341] *pde = 00000000
>> Aug 13 23:59:00 debian kernel: [435848.980374] Oops: 0000 [#2] SMP
>> Aug 13 23:59:00 debian kernel: [435848.980410] last sysfs file:
>> /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0A08:00/device:00/PNP0C09:00/PNP0C0A:00/power_supply/BAT0/energy_full
>> Aug 13 23:59:00 debian kernel: [435848.980486] Modules linked in: btrfs
>> zlib_deflate crc32c libcrc32c loop joydev i915 drm_kms_helper pcmcia
>> thinkpad_acpi rfkill drm parport_pc snd_intel8x0 snd_ac97_codec ac97_bus
>> led_class yenta_socket i2c_algo_bit snd_pcm i2c_i801 parport rsrc_nonstatic
>> psmouse serio_raw snd_timer video pcmcia_core nvram pcspkr i2c_core output
>> evdev snd rng_core soundcore battery ac processor button snd_page_alloc ext3
>> jbd mbcache ata_generic sd_mod crc_t10dif ata_piix uhci_hcd ahci sata_sil24
>> tg3 thermal ehci_hcd usbcore libata scsi_mod libphy thermal_sys nls_base
>> [last unloaded: scsi_wait_scan]
>> Aug 13 23:59:00 debian kernel: [435848.980901]
>> Aug 13 23:59:00 debian kernel: [435848.980931] Pid: 8795, comm: umount
>> Tainted: G      D    (2.6.32-5-686 #1) 18714AG
>> Aug 13 23:59:00 debian kernel: [435848.980995] EIP: 0060:[<f8a21d84>]
>> EFLAGS: 00010292 CPU: 0
>> Aug 13 23:59:00 debian kernel: [435848.981057] EIP is at
>> btrfs_print_leaf+0xe/0x765 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.981095] EAX: f66be800 EBX: f66be800
>> ECX: c1ba0140 EDX: 00000000
>> Aug 13 23:59:00 debian kernel: [435848.981135] ESI: 00000000 EDI: f69f4000
>> EBP: 00000000 ESP: f629fcdc
>> Aug 13 23:59:00 debian kernel: [435848.981176]  DS: 007b ES: 007b FS: 00d8
>> GS: 00e0 SS: 0068
>> Aug 13 23:59:00 debian kernel: [435848.981216] Process umount (pid: 8795,
>> ti=f629e000 task=f60b9540 task.ti=f629e000)
>> Aug 13 23:59:00 debian kernel: [435848.981276] Stack:
>> Aug 13 23:59:00 debian kernel: [435848.981304]  00000000 00000000 00000000
>> 00000086 8777d000 f69f4000 f66be800 f6802c00
>> Aug 13 23:59:00 debian kernel: [435848.981359] <0> f28c0d40 b7766000
>> c108c611 ffffffff 000000b0 0000000b 00000001 00000000
>> Aug 13 23:59:00 debian kernel: [435848.981436] <0> 868777d0 a8000000
>> 00001000 00000000 00000005 00000000 f69f4000 00000000
>> Aug 13 23:59:00 debian kernel: [435848.981532] Call Trace:
>> Aug 13 23:59:00 debian kernel: [435848.981572]  [<c108c611>] ?
>> __alloc_pages_nodemask+0xf3/0x4d9
>> Aug 13 23:59:00 debian kernel: [435848.981636]  [<f8a1eb7d>] ?
>> __btrfs_free_extent+0xe3/0x743 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.981700]  [<f8a1ed9d>] ?
>> __btrfs_free_extent+0x303/0x743 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.981765]  [<f8a1f6a7>] ?
>> run_one_delayed_ref+0x4ca/0x4df [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.981811]  [<c1001f10>] ?
>> __switch_to+0xcf/0x141
>> Aug 13 23:59:00 debian kernel: [435848.981872]  [<f8a215e9>] ?
>> run_clustered_refs+0x1f2/0x22d [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.981938]  [<f8a216d9>] ?
>> btrfs_run_delayed_refs+0xb5/0x138 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.982007]  [<f8a2a411>] ?
>> btrfs_commit_transaction+0x69/0x5a1 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.982077]  [<f8a2a118>] ?
>> start_transaction+0x19/0x110 [btrfs]
>> Aug 13 23:59:00 debian kernel: [435848.983197]  [<c104432e>] ?
>> autoremove_wake_function+0x0/0x2d
>> Aug 13 23:59:00 debian kernel: [435848.983241]  [<c10e4d02>] ?
>> sync_quota_sb+0x3a/0xca
>> Aug 13 23:59:00 debian kernel: [435848.983282]  [<c10ccd78>] ?
>> __sync_filesystem+0x3a/0x60
>> Aug 13 23:59:00 debian kernel: [435848.983325]  [<c10b5513>] ?
>> generic_shutdown_super+0x19/0xc6
>> Aug 13 23:59:00 debian kernel: [435848.983367]  [<c10e3e16>] ?
>> vfs_quota_off+0x0/0xd
>> Aug 13 23:59:00 debian kernel: [435848.983406]  [<c10b55f5>] ?
>> kill_anon_super+0x9/0x3b
>> Aug 13 23:59:00 debian kernel: [435848.983446]  [<c10b5b77>] ?
>> deactivate_super+0x4a/0x5f
>> Aug 13 23:59:00 debian kernel: [435848.983488]  [<c10c5b5b>] ?
>> sys_umount+0x2a5/0x2cb
>> Aug 13 23:59:00 debian kernel: [435848.983528]  [<c10c5b8c>] ?
>> sys_oldumount+0xb/0xe
>> Aug 13 23:59:00 debian kernel: [435848.983567]  [<c10030fb>] ?
>> sysenter_do_call+0x12/0x28
>> Aug 13 23:59:00 debian kernel: [435848.983603] Code: 24 08 ff 74 24 18 ff 74
>> 24 18 52 50 68 03 d7 a5 f8 e8 36 b9 84 c8 83 c4 30 5b 5e 5f c3 55 89 d5 57
>> 56 53 89 c3 81 ec 88 00 00 00 <8b> 42 1c ba 03 00 00 00 e8 52 db 5f c8 8b 50
>> 60 89 54 24 20 ba
>> Aug 13 23:59:00 debian kernel: [435848.983823] EIP: [<f8a21d84>]
>> btrfs_print_leaf+0xe/0x765 [btrfs] SS:ESP 0068:f629fcdc
>> Aug 13 23:59:00 debian kernel: [435848.983914] CR2: 000000000000001c
>> Aug 13 23:59:00 debian kernel: [435848.984328] ---[ end trace
>> 31cd148f196f7434 ]---
>>
>> --
>> Stefan Harwarth
>> 85051 Ingolstadt
>>
>> --
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>

-- 
Stefan Harwarth
85051 Ingolstadt