After seeking advice on reddit I've been advised to post this problem here. See https://www.reddit.com/r/btrfs/comments/bp0awe/broken_btrfs_filesystem_following_a_reboot/ I have a root btrfs filesystem on top of mdadm raid10 and lvm. The raid and lvm appear to be ok but the btrfs partition will not mount. I have booted a live recovery and tried to mount/repair the filesystem. This is the result. % mount /dev/mapper/vg-root /mnt/gentoo mount: /mnt/gentoo: wrong fs type, bad option, bad superblock on /dev/mapper/vg-root, missing codepage or helper program, or other error. Trying to mount with recovery gives the same result: % mount -o ro,recovery /dev/mapper/vg-root /mnt/gentoo mount: /mnt/gentoo: wrong fs type, bad option, bad superblock on /dev/mapper/vg-root, missing codepage or helper program, or other error. And a btrfs check gives the following: % btrfs check --repair /dev/mapper/vg-root enabling repair mode bytenr mismatch, want=898031484928, have=898006728704 ERROR: cannot open file system % dmesg | grep -i btrfs [ 5.562419] Btrfs loaded, crc32c=crc32c-generic [ 14.381989] BTRFS: device fsid 1fb019f1-a8cc-46ef-8122-ac6b1bedd522 devid 1 transid 51979 /dev/dm-1 [ 14.382647] BTRFS info (device dm-1): disk space caching is enabled [ 14.382652] BTRFS info (device dm-1): has skinny extents [ 15.777186] BTRFS error (device dm-1): bad tree block start 0 898031337472 [ 15.777334] BTRFS error (device dm-1): bad tree block start 0 898031353856 [ 15.777486] BTRFS error (device dm-1): bad tree block start 0 898031370240 [ 15.864239] BTRFS error (device dm-1): bad tree block start 898006728704 898031484928 [ 15.871367] BTRFS error (device dm-1): bad tree block start 898003812352 898031484928 [ 15.871382] BTRFS error (device dm-1): failed to read block groups: -5 [ 15.892051] BTRFS error (device dm-1): open_ctree failed [ 16.016182] BTRFS info (device dm-1): disk space caching is enabled [ 16.016186] BTRFS info (device dm-1): has skinny extents [ 17.319016] BTRFS error (device dm-1): bad tree block start 0 898031337472 [ 17.319157] BTRFS error (device dm-1): bad tree block start 0 898031353856 [ 17.319303] BTRFS error (device dm-1): bad tree block start 0 898031370240 [ 17.422706] BTRFS error (device dm-1): bad tree block start 898006728704 898031484928 [ 17.429831] BTRFS error (device dm-1): bad tree block start 898003812352 898031484928 [ 17.429845] BTRFS error (device dm-1): failed to read block groups: -5 [ 17.450035] BTRFS error (device dm-1): open_ctree failed % uname -r 4.14.70-std531-amd64 % wipefs /dev/mapper/vg-root DEVICE OFFSET TYPE UUID LABEL vg-root 0x10040 btrfs 1fb019f1-a8cc-46ef-8122-ac6b1bedd522 I was asked to try with a more recent kernel. I booted archiso which showed similar results. # uname -r 5.0.10-arch1-1-ARCH # mount /dev/mapper/vg-root /mnt/funtoo [ 208.724214] BTRFS error (device dm-1): bad tree block start, want 898031337472 have 0 [ 208.724343] BTRFS error (device dm-1): bad tree block start, want 898031353856 have 0 [ 208.724556] BTRFS error (device dm-1): bad tree block start, want 898031370240 have 0 [ 208.805279] BTRFS error (device dm-1): bad tree block start, want 898031484928 have 898006728704 [ 208.812412] BTRFS error (device dm-1): bad tree block strat, want 898031484928 have 898003812352 [ 208.812451] BTRFS error (device dm-1): failed to read block groups: -5 [ 208.840576] BTRFS error (device dm-1): open_ctree failed mount: /mnt/funtoo: wrong fs type, bad option, bad superblock on /dev/mapper/vg-root, missing codepage or helper program, or other error. 32 # dmesg|grep -i btrfs [ 23.028283] Btrfs loaded, crc32c=crc32c-intel [ 23.061402] BTRFS: device fsid 1fb019f1-a8cc-46ef-8122-ac6b1bedd522 devid 1 transid 51979 /dev/dm-1 [ 207.437375] BTRFS info (device dm-1): disk space caching is enabled [ 207.437379] BTRFS info (device dm-1): has skinny extents [ 208.724214] BTRFS error (device dm-1): bad tree block start, want 898031337472 have 0 [ 208.724343] BTRFS error (device dm-1): bad tree block start, want 898031353856 have 0 [ 208.724556] BTRFS error (device dm-1): bad tree block start, want 898031370240 have 0 [ 208.805279] BTRFS error (device dm-1): bad tree block start, want 898031484928 have 898006728704 [ 208.812412] BTRFS error (device dm-1): bad tree block start, want 898031484928 have 898003812352 [ 208.812451] BTRFS error (device dm-1): failed to read block groups: -5 [ 208.840576] BTRFS error (device dm-1): open_ctree failed Any idea if this can be fixed? Cheers Lee
