RAID1 fails to recover chunk tree

[Zack Coffey <tech42.clickwir@gmail.com>]

Revisit of a previous issue. Setup a single 640GB drive with BTRFS and
compression. This was not a system drive, just a place to put random
junk.

Made a RAID1 with another drive of just the metadata. Was in
that state for less than 12 hours-ish, removed the second drive and
now cannot get to any data on the original drive. Data remained single
while only metadata was RAID1.

Single drive btrfs was made on Ubuntu with kernel 3.13.0 and tools
3.12.

$ sudo mount -o degraded /dev/sdc1 /media/Data/
mount: wrong fs type, bad option, bad superblock on /dev/sdc1,
        missing codepage or helper program, or other error
        In some cases useful info is found in syslog - try
        dmesg | tail  or so

$ dmesg | tail
[45353.869448] KBD BUG in
../../../../../../../../
drivers/2d/lnx/fgl/drm/kernel/
gal.c at line:
304!
[45353.901511] KBD BUG in
../../../../../../../../
drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
304!
[45353.901666] KBD BUG in
../../../../../../../../drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
304!
[45354.148488] KBD BUG in
../../../../../../../../drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
304!
[45354.148573] KBD BUG in
../../../../../../../../drivers/2d/lnx/fgl/drm/kernel/gal.c at line:
304!
[46241.155350] btrfs: device fsid bd78815a-802b-43e2-8387-fc6ab4237d67
devid 1 transid 60944 /dev/sdc1
[46241.155923] btrfs: allowing degraded mounts
[46241.155927] btrfs: disk space caching is enabled
[46241.159436] btrfs: failed to read chunk root on sdc1
[46241.177815] btrfs: open_ctree failed

$ btrfs-show-super /dev/sdc1
superblock: bytenr=65536, device=/dev/sdc1
------------------------------
---------------------------
csum                    0x93bcb1b5 [match]
bytenr                  65536
flags                   0x1
magic                   _BHRfS_M [match]
fsid                    bd78815a-802b-43e2-8387-fc6ab4237d67
label
generation              60944
root                    909586694144
sys_array_size          97
chunk_root_generation   60938
root_level              1
chunk_root              911673917440
chunk_root_level        1
log_root                0
log_root_transid        0
log_root_level          0
total_bytes             1115871535104
bytes_used              321833435136
sectorsize              4096
nodesize                4096
leafsize                4096
stripesize              4096
root_dir                6
num_devices             2
compat_flags            0x0
compat_ro_flags         0x0
incompat_flags          0x9
csum_type               0
csum_size               4
cache_generation        60944
uuid_tree_generation    60944
dev_item.uuid           d82b2027-17b6-4513-a86d-9227a42d7ed1
dev_item.fsid           bd78815a-802b-43e2-8387-fc6ab4237d67 [match]
dev_item.type           0
dev_item.total_bytes    615763673088
dev_item.bytes_used     324270030848
dev_item.io_align       4096
dev_item.io_width       4096
dev_item.sector_size    4096
dev_item.devid          1
dev_item.dev_group      0
dev_item.seek_speed     0
dev_item.bandwidth      0
dev_item.generation     0


$ sudo btrfs device add -f /dev/sdh1 /dev/sdc1
ERROR: error adding the device '/dev/sdh1' - Inappropriate ioctl for device

$ sudo btrfs device delete missing /dev/sdc1
ERROR: error removing the device 'missing' - Inappropriate ioctl for device

$ sudo mount -o degraded,defaults,compress=lzo /dev/sdc1 /media/Data/
mount: wrong fs type, bad option, bad superblock on /dev/sdc1,
        missing codepage or helper program, or other error
        In some cases useful info is found in syslog - try
        dmesg | tail  or so

$ dmesg | tail
[106991.655384] btrfs: device fsid
bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
[106991.665066] btrfs: device fsid
bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
[107019.954397] btrfs: device fsid
bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
[107019.962009] btrfs: device fsid
bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
[107070.124927] btrfs: device fsid
bd78815a-802b-43e2-8387-fc6ab4237d67 devid 1 transid 60944 /dev/sdc1
[107070.126475] btrfs: allowing degraded mounts
[107070.126479] btrfs: use lzo compression
[107070.126480] btrfs: disk space caching is enabled
[107070.127254] btrfs: failed to read chunk root on sdc1
[107070.142983] btrfs: open_ctree failed

$ sudo btrfs rescue super-recover -v /dev/sdc1
All Devices:
         Device: id = 1, name = /dev/sdc1

Before Recovering:
         [All good supers]:
                 device name = /dev/sdc1
                 superblock bytenr = 65536

                 device name = /dev/sdc1
                 superblock bytenr = 67108864

                 device name = /dev/sdc1
                 superblock bytenr = 274877906944

         [All bad supers]:

All supers are valid, no need to recover

$ btrfs rescue chunk-recover -v /dev/sdc1
<<snipped>>
Chunk: start = 860100755456, len = 1073741824, type = 1, num_stripes = 1
       Stripes list:
       [ 0] Stripe: devid = 1, offset = 26877100032
       No block group.
       No device extent.
   Chunk: start = 861174497280, len = 1073741824, type = 1, num_stripes = 1
       Stripes list:
       [ 0] Stripe: devid = 1, offset = 27950841856
       No block group.
       No device extent.

Total Chunks:   333
   Heathy:       305
   Bad:  28

Orphan Block Groups:
   Block Group: start = 872985657344, len = 1073741824, flag = 4
   Block Group: start = 911673917440, len = 33554432, flag = 2
   Block Group: start = 911707471872, len = 1073741824, flag = 4

Orphan Device Extents:
   Device extent: devid = 2, start = 2182086656, len = 33554432, chunk
offset = 911673917440
   Device extent: devid = 2, start = 2215641088, len = 1073741824,
chunk offset = 911707471872
Fail to recover the chunk tree.
<</snipped>>

Here's the full snipped paste: http://pastebin.com/fEm3Gup7

Now I'm on openSUSE Tumbleweed (kernel 3.17). Still get the same
result from 'chunk-recover'. There's 305 healthy chunks, is there
anyway to recover that data and forget about the bad ones?

A good portion of the data on that drive was backed up, but some
wasn't. My fault, I've learned. Can I get anything back from that
drive?

Thanks