On 2018年03月06日 09:51, Ken Swenson wrote: > 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)
This is obviously corrupted. Btrfs only supports csum_type 0 (CRC32) yet. And the value seems to be some garbage. > csum_size 32 So is the csum size. > csum > 0xf0dbeddd00000000000000000000000000000000000000000000000000000000 [match] Surprised to see the csum even matched. > 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 ) And unknown flags also exists. And according to later output, all backup super blocks have the same corruption while csum still matches. I'm wondering if the memory is corrupted. It's possible to manually modify the superblock to a valid status. As all the corruption is obvious, but I'm not 100% sure if there is other corruption. Please provide the binary superblock dump by: dd if=<device> bs=1 count=4K skip=64K of=super_copy Thanks, Qu > 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 > >
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