Hi,
TL;DR: I want to save data from my unmountable btrfs partition.
I saw some commands in another thread "Salvage files from broken btrfs".
I use the most recent Manjaro live (kernel: 4.19.0-3-MANJARO,
btrfs-progs 4.17.1-1) to execute these commands.
$ sudo mount -o ro,nologreplay /dev/nvme0n1p2 /mnt
mount: /mnt: wrong fs type, bad option, bad superblock on
/dev/nvme0n1p2, missing codepage or helper program, or other error.
Corresponding lines from dmesg:
[ 1517.772302] BTRFS info (device nvme0n1p2): disabling log replay at mount time
[ 1517.772307] BTRFS info (device nvme0n1p2): disk space caching is enabled
[ 1517.772310] BTRFS info (device nvme0n1p2): has skinny extents
[ 1517.793414] BTRFS error (device nvme0n1p2): bad tree block start,
want 18811453440 have 0
[ 1517.793430] BTRFS error (device nvme0n1p2): failed to read block groups: -5
[ 1517.808619] BTRFS error (device nvme0n1p2): open_ctree failed
$ sudo btrfs-find-root /dev/nvme0n1p2
Superblock thinks the generation is 220524
Superblock thinks the level is 1
Found tree root at 25018368 gen 220524 level 1
Well block 4243456(gen: 220520 level: 1) seems good, but
generation/level doesn't match, want gen: 220524 level: 1
Well block 5259264(gen: 220519 level: 1) seems good, but
generation/level doesn't match, want gen: 220524 level: 1
Well block 4866048(gen: 220518 level: 0) seems good, but
generation/level doesn't match, want gen: 220524 level: 1
$ sudo btrfs ins dump-super -Ffa /dev/nvme0n1p2
superblock: bytenr=65536, device=/dev/nvme0n1p2
---------------------------------------------------------
csum_type 0 (crc32c)
csum_size 4
csum 0x7956a931 [match]
bytenr 65536
flags 0x1
( WRITTEN )
magic _BHRfS_M [match]
fsid 014c9d24-339c-482e-8f06-9284e4a7bc40
label newhome
generation 220524
root 25018368
sys_array_size 97
chunk_root_generation 219209
root_level 1
chunk_root 131072
chunk_root_level 1
log_root 86818816
log_root_transid 0
log_root_level 0
total_bytes 355938074624
bytes_used 344504737792
sectorsize 4096
nodesize 16384
leafsize (deprecated) 16384
stripesize 4096
root_dir 6
num_devices 1
compat_flags 0x0
compat_ro_flags 0x0
incompat_flags 0x161
( MIXED_BACKREF |
BIG_METADATA |
EXTENDED_IREF |
SKINNY_METADATA )
cache_generation 220524
uuid_tree_generation 220524
dev_item.uuid 05fe6ce8-1f2d-41ba-a367-cbdb8f06ffd3
dev_item.fsid 014c9d24-339c-482e-8f06-9284e4a7bc40 [match]
dev_item.type 0
dev_item.total_bytes 355938074624
dev_item.bytes_used 355792322560
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
sys_chunk_array[2048]:
item 0 key (FIRST_CHUNK_TREE CHUNK_ITEM 0)
length 4194304 owner 2 stripe_len 65536 type SYSTEM
io_align 4096 io_width 4096 sector_size 4096
num_stripes 1 sub_stripes 0
stripe 0 devid 1 offset 0
dev_uuid 05fe6ce8-1f2d-41ba-a367-cbdb8f06ffd3
backup_roots[4]:
backup 0:
backup_tree_root: 42598400 gen: 220522 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 26460160 gen: 220522 level: 2
backup_fs_root: 51347456 gen: 220523 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 26558464 gen: 220522 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504741888
backup_num_devices: 1
backup 1:
backup_tree_root: 52363264 gen: 220523 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 51806208 gen: 220523 level: 2
backup_fs_root: 51347456 gen: 220523 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 52461568 gen: 220523 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504729600
backup_num_devices: 1
backup 2:
backup_tree_root: 25018368 gen: 220524 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 21479424 gen: 220524 level: 2
backup_fs_root: 53084160 gen: 220524 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 53379072 gen: 220524 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504737792
backup_num_devices: 1
backup 3:
backup_tree_root: 21921792 gen: 220521 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 5570560 gen: 220521 level: 2
backup_fs_root: 4571136 gen: 220521 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 5619712 gen: 220521 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344506957824
backup_num_devices: 1
superblock: bytenr=67108864, device=/dev/nvme0n1p2
---------------------------------------------------------
csum_type 0 (crc32c)
csum_size 4
csum 0x36d97b1b [match]
bytenr 67108864
flags 0x1
( WRITTEN )
magic _BHRfS_M [match]
fsid 014c9d24-339c-482e-8f06-9284e4a7bc40
label newhome
generation 220524
root 25018368
sys_array_size 97
chunk_root_generation 219209
root_level 1
chunk_root 131072
chunk_root_level 1
log_root 0
log_root_transid 0
log_root_level 0
total_bytes 355938074624
bytes_used 344504737792
sectorsize 4096
nodesize 16384
leafsize (deprecated) 16384
stripesize 4096
root_dir 6
num_devices 1
compat_flags 0x0
compat_ro_flags 0x0
incompat_flags 0x161
( MIXED_BACKREF |
BIG_METADATA |
EXTENDED_IREF |
SKINNY_METADATA )
cache_generation 220524
uuid_tree_generation 220524
dev_item.uuid 05fe6ce8-1f2d-41ba-a367-cbdb8f06ffd3
dev_item.fsid 014c9d24-339c-482e-8f06-9284e4a7bc40 [match]
dev_item.type 0
dev_item.total_bytes 355938074624
dev_item.bytes_used 355792322560
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
sys_chunk_array[2048]:
item 0 key (FIRST_CHUNK_TREE CHUNK_ITEM 0)
length 4194304 owner 2 stripe_len 65536 type SYSTEM
io_align 4096 io_width 4096 sector_size 4096
num_stripes 1 sub_stripes 0
stripe 0 devid 1 offset 0
dev_uuid 05fe6ce8-1f2d-41ba-a367-cbdb8f06ffd3
backup_roots[4]:
backup 0:
backup_tree_root: 42598400 gen: 220522 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 26460160 gen: 220522 level: 2
backup_fs_root: 51347456 gen: 220523 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 26558464 gen: 220522 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504741888
backup_num_devices: 1
backup 1:
backup_tree_root: 52363264 gen: 220523 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 51806208 gen: 220523 level: 2
backup_fs_root: 51347456 gen: 220523 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 52461568 gen: 220523 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504729600
backup_num_devices: 1
backup 2:
backup_tree_root: 25018368 gen: 220524 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 21479424 gen: 220524 level: 2
backup_fs_root: 53084160 gen: 220524 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 53379072 gen: 220524 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504737792
backup_num_devices: 1
backup 3:
backup_tree_root: 21921792 gen: 220521 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 5570560 gen: 220521 level: 2
backup_fs_root: 4571136 gen: 220521 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 5619712 gen: 220521 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344506957824
backup_num_devices: 1
superblock: bytenr=274877906944, device=/dev/nvme0n1p2
---------------------------------------------------------
csum_type 0 (crc32c)
csum_size 4
csum 0xcb5e2d2a [match]
bytenr 274877906944
flags 0x1
( WRITTEN )
magic _BHRfS_M [match]
fsid 014c9d24-339c-482e-8f06-9284e4a7bc40
label newhome
generation 220524
root 25018368
sys_array_size 97
chunk_root_generation 219209
root_level 1
chunk_root 131072
chunk_root_level 1
log_root 0
log_root_transid 0
log_root_level 0
total_bytes 355938074624
bytes_used 344504737792
sectorsize 4096
nodesize 16384
leafsize (deprecated) 16384
stripesize 4096
root_dir 6
num_devices 1
compat_flags 0x0
compat_ro_flags 0x0
incompat_flags 0x161
( MIXED_BACKREF |
BIG_METADATA |
EXTENDED_IREF |
SKINNY_METADATA )
cache_generation 220524
uuid_tree_generation 220524
dev_item.uuid 05fe6ce8-1f2d-41ba-a367-cbdb8f06ffd3
dev_item.fsid 014c9d24-339c-482e-8f06-9284e4a7bc40 [match]
dev_item.type 0
dev_item.total_bytes 355938074624
dev_item.bytes_used 355792322560
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
sys_chunk_array[2048]:
item 0 key (FIRST_CHUNK_TREE CHUNK_ITEM 0)
length 4194304 owner 2 stripe_len 65536 type SYSTEM
io_align 4096 io_width 4096 sector_size 4096
num_stripes 1 sub_stripes 0
stripe 0 devid 1 offset 0
dev_uuid 05fe6ce8-1f2d-41ba-a367-cbdb8f06ffd3
backup_roots[4]:
backup 0:
backup_tree_root: 42598400 gen: 220522 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 26460160 gen: 220522 level: 2
backup_fs_root: 51347456 gen: 220523 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 26558464 gen: 220522 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504741888
backup_num_devices: 1
backup 1:
backup_tree_root: 52363264 gen: 220523 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 51806208 gen: 220523 level: 2
backup_fs_root: 51347456 gen: 220523 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 52461568 gen: 220523 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504729600
backup_num_devices: 1
backup 2:
backup_tree_root: 25018368 gen: 220524 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 21479424 gen: 220524 level: 2
backup_fs_root: 53084160 gen: 220524 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 53379072 gen: 220524 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344504737792
backup_num_devices: 1
backup 3:
backup_tree_root: 21921792 gen: 220521 level: 1
backup_chunk_root: 131072 gen: 219209 level: 1
backup_extent_root: 5570560 gen: 220521 level: 2
backup_fs_root: 4571136 gen: 220521 level: 2
backup_dev_root: 4472832 gen: 220520 level: 1
backup_csum_root: 5619712 gen: 220521 level: 2
backup_total_bytes: 355938074624
backup_bytes_used: 344506957824
backup_num_devices: 1
If I understood correctly, somehow it is possible to use this data to
parametrize btrfs restore to save the files from the partition.
Could you please help how to do it in this case? I am not familiar
with these technical terms in the outputs.
Thanks in advance!
Cheers,
Attila
On Thu, Nov 1, 2018 at 8:40 PM Attila Vangel <vangel.attila@xxxxxxxxx> wrote:
>
> Hi,
>
> Somehow my btrfs partition got broken. I use Arch, so my kernel is
> quite new (4.18.x).
> I don't remember exactly the sequence of events. At some point it was
> accessible in read-only, but unfortunately I did not take backup
> immediately. dmesg log from that time:
>
> [ 62.602388] BTRFS warning (device nvme0n1p2): block group
> 103923318784 has wrong amount of free space
> [ 62.602390] BTRFS warning (device nvme0n1p2): failed to load free
> space cache for block group 103923318784, rebuilding it now
> [ 108.039188] BTRFS error (device nvme0n1p2): bad tree block start 0 18812026880
> [ 108.039227] BTRFS: error (device nvme0n1p2) in
> __btrfs_free_extent:7010: errno=-5 IO failure
> [ 108.039241] BTRFS info (device nvme0n1p2): forced readonly
> [ 108.039250] BTRFS: error (device nvme0n1p2) in
> btrfs_run_delayed_refs:3076: errno=-5 IO failure
>
> At the next reboot it failed to mount. Problem may have been that at
> some point I booted to another distro with older kernel (4.15.x,
> 4.14.52) and unfortunately attempted some checks/repairs (?) e.g. from
> gparted, and at that time I did not know it could be destructive.
>
> Anyway, currently it fails to mount (even with ro and/or recovery),
> btrfs check results in "checksum verify failed" and "bad tree block"
> errors, btrfs restore resulted in "We have looped trying to restore
> files in" errors for a dozen of paths then exit.
>
> Is there some hope to save data from the filesystem, and if so, how?
>
> BTW I checked some diagnostics commands regarding my SSD with the nvme
> client and from that it seems there are no hardware problems.
>
> Your help is highly appreciated.
>
> Cheers,
> Attila
