Hello, Somehow it appears the csum_type on my btrfs file system got corrupted. I cannot mount the system in recovery or read only. btrfs check just returns "ERROR: unsupported checksum algorithm 35355" as well as btrfs recover. The only command I was able to successfully run was btrfs inspect-internal dump-super, which I've pasted the output at the end of this message.
Requested information from the wiki: Linux 4.15.7-1-ARCH #1 SMP PREEMPT Wed Feb 28 19:01:57 UTC 2018 x86_64 GNU/Linux btrfs-progs v4.15.1 btrfs fi show: ERROR: unsupported checksum algorithm 35355 ERROR: cannot scan /dev/mapper/x: Input/output error dmesg: [ 11.232399] Btrfs loaded, crc32c=crc32c-intel [ 11.233229] BTRFS: device fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f devid 1 transid 7777 /dev/dm-2 [ 488.372891] BTRFS error (device dm-2): unsupported checksum algorithm 35355 [ 488.372894] BTRFS error (device dm-2): superblock checksum mismatch [ 488.384902] BTRFS error (device dm-2): open_ctree failed Is there anything I can do to recovery from this or am I out of luck? To give some background the disk was working fine until I upgraded to Kernel 4.15.7 and rebooted. superblock: bytenr=65536, device=/dev/mapper/x --------------------------------------------------------- csum_type 35355 (INVALID) csum_size 32 csum 0xf0dbeddd00000000000000000000000000000000000000000000000000000000 [match] bytenr 65536 flags 0x1 ( WRITTEN ) magic _BHRfS_M [match] fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f label generation 7777 root 186466304 sys_array_size 129 chunk_root_generation 7450 root_level 1 chunk_root 21004288 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 5000947523584 bytes_used 420849201152 sectorsize 4096 nodesize 16384 leafsize (deprecated) 16384 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0x176d200000000169 ( MIXED_BACKREF | COMPRESS_LZO | BIG_METADATA | EXTENDED_IREF | SKINNY_METADATA | unknown flag: 0x176d200000000000 ) cache_generation 7777 uuid_tree_generation 7777 dev_item.uuid 880c692f-5270-4c7a-908d-8b3956fb3790 dev_item.fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f [match] dev_item.type 0 dev_item.total_bytes 5000947523584 dev_item.bytes_used 457439182848 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 20971520) length 8388608 owner 2 stripe_len 65536 type SYSTEM|DUP io_align 65536 io_width 65536 sector_size 4096 num_stripes 2 sub_stripes 0 stripe 0 devid 1 offset 20971520 dev_uuid 880c692f-5270-4c7a-908d-8b3956fb3790 stripe 1 devid 1 offset 29360128 dev_uuid 880c692f-5270-4c7a-908d-8b3956fb3790 backup_roots[4]: backup 0: backup_tree_root: 181174272 gen: 7774 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 181190656 gen: 7774 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 93585408 gen: 7631 level: 1 backup_csum_root: 181862400 gen: 7774 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 1: backup_tree_root: 183828480 gen: 7775 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 183320576 gen: 7775 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 185761792 gen: 7775 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 2: backup_tree_root: 186810368 gen: 7776 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 186613760 gen: 7776 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 187056128 gen: 7776 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 3: backup_tree_root: 186466304 gen: 7777 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 187908096 gen: 7777 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 188071936 gen: 7777 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 superblock: bytenr=67108864, device=/dev/mapper/x --------------------------------------------------------- csum_type 35355 (INVALID) csum_size 32 csum 0x50bac51300000000000000000000000000000000000000000000000000000000 [DON'T MATCH] bytenr 67108864 flags 0x1 ( WRITTEN ) magic _BHRfS_M [match] fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f label generation 7777 root 186466304 sys_array_size 129 chunk_root_generation 7450 root_level 1 chunk_root 21004288 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 5000947523584 bytes_used 420849201152 sectorsize 4096 nodesize 16384 leafsize (deprecated) 16384 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0x176d200000000169 ( MIXED_BACKREF | COMPRESS_LZO | BIG_METADATA | EXTENDED_IREF | SKINNY_METADATA | unknown flag: 0x176d200000000000 ) cache_generation 7777 uuid_tree_generation 7777 dev_item.uuid 880c692f-5270-4c7a-908d-8b3956fb3790 dev_item.fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f [match] dev_item.type 0 dev_item.total_bytes 5000947523584 dev_item.bytes_used 457439182848 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 20971520) length 8388608 owner 2 stripe_len 65536 type SYSTEM|DUP io_align 65536 io_width 65536 sector_size 4096 num_stripes 2 sub_stripes 0 stripe 0 devid 1 offset 20971520 dev_uuid 880c692f-5270-4c7a-908d-8b3956fb3790 stripe 1 devid 1 offset 29360128 dev_uuid 880c692f-5270-4c7a-908d-8b3956fb3790 backup_roots[4]: backup 0: backup_tree_root: 181174272 gen: 7774 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 181190656 gen: 7774 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 93585408 gen: 7631 level: 1 backup_csum_root: 181862400 gen: 7774 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 1: backup_tree_root: 183828480 gen: 7775 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 183320576 gen: 7775 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 185761792 gen: 7775 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 2: backup_tree_root: 186810368 gen: 7776 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 186613760 gen: 7776 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 187056128 gen: 7776 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 3: backup_tree_root: 186466304 gen: 7777 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 187908096 gen: 7777 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 188071936 gen: 7777 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 superblock: bytenr=274877906944, device=/dev/mapper/x --------------------------------------------------------- csum_type 35355 (INVALID) csum_size 32 csum 0xad3d932200000000000000000000000000000000000000000000000000000000 [DON'T MATCH] bytenr 274877906944 flags 0x1 ( WRITTEN ) magic _BHRfS_M [match] fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f label generation 7777 root 186466304 sys_array_size 129 chunk_root_generation 7450 root_level 1 chunk_root 21004288 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 5000947523584 bytes_used 420849201152 sectorsize 4096 nodesize 16384 leafsize (deprecated) 16384 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0x176d200000000169 ( MIXED_BACKREF | COMPRESS_LZO | BIG_METADATA | EXTENDED_IREF | SKINNY_METADATA | unknown flag: 0x176d200000000000 ) cache_generation 7777 uuid_tree_generation 7777 dev_item.uuid 880c692f-5270-4c7a-908d-8b3956fb3790 dev_item.fsid 513f07e1-08be-4d94-a55c-11c6251f6c2f [match] dev_item.type 0 dev_item.total_bytes 5000947523584 dev_item.bytes_used 457439182848 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 20971520) length 8388608 owner 2 stripe_len 65536 type SYSTEM|DUP io_align 65536 io_width 65536 sector_size 4096 num_stripes 2 sub_stripes 0 stripe 0 devid 1 offset 20971520 dev_uuid 880c692f-5270-4c7a-908d-8b3956fb3790 stripe 1 devid 1 offset 29360128 dev_uuid 880c692f-5270-4c7a-908d-8b3956fb3790 backup_roots[4]: backup 0: backup_tree_root: 181174272 gen: 7774 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 181190656 gen: 7774 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 93585408 gen: 7631 level: 1 backup_csum_root: 181862400 gen: 7774 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 1: backup_tree_root: 183828480 gen: 7775 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 183320576 gen: 7775 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 185761792 gen: 7775 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 2: backup_tree_root: 186810368 gen: 7776 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 186613760 gen: 7776 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 187056128 gen: 7776 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 backup 3: backup_tree_root: 186466304 gen: 7777 level: 1 backup_chunk_root: 21004288 gen: 7450 level: 1 backup_extent_root: 187908096 gen: 7777 level: 2 backup_fs_root: 809828352 gen: 6404 level: 0 backup_dev_root: 183975936 gen: 7775 level: 1 backup_csum_root: 188071936 gen: 7777 level: 2 backup_total_bytes: 5000947523584 backup_bytes_used: 420849201152 backup_num_devices: 1 Thank you, Ken N�����r��y����b�X��ǧv�^�){.n�+����{�n�߲)����w*jg��������ݢj/���z�ޖ��2�ޙ����&�)ߡ�a�����G���h��j:+v���w��٥