root@youpi:~# fsck.bcachefs /dev/nvme0n1p4 /dev/sda1
Running userspace offline fsck
starting version 1.12: rebalance_work_acct_fix opts=ro,foreground_target=/dev//dev/nvme0n1p4,background_target=/dev//dev/sda1,promote_target=/dev//dev/nvme0n1p4,nopromote_whole_extents,degraded,fsck,fix_errors=ask,nojournal_transaction_names,read_only
recovering from clean shutdown, journal seq 3303258
accounting_read...invalid bkey u64s 6 type accounting 0:9:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:12:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:15:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:16:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:17:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:19:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
 done
alloc_read... done
stripes_read... done
snapshots_read... done
check_allocations...invalid bkey u64s 6 type accounting 0:9:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:12:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:15:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:16:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:17:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:19:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
 done
going read-write
journal_replay... done
check_alloc_info... done
check_lrus... done
check_btree_backpointers... done
check_backpointers_to_extents...backpointers_to_extents: 2%, done 57/2772 nodes, at backpointers:0:70756335616:0
invalid bkey u64s 6 type accounting 0:9:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:12:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:15:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:16:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
backpointers_to_extents: 3%, done 88/2772 nodes, at backpointers:0:123076083712:0
backpointers_to_extents: 4%, done 121/2772 nodes, at backpointers:0:176921509888:0
backpointers_to_extents: 59%, done 1645/2772 nodes, at backpointers:1:231353729024:0
 done
check_extents_to_backpointers...extents_to_backpointers: 88%, done 4260/4811 nodes, at extents:405780440:128:4294967213
 done
check_alloc_to_lru_refs... done
check_snapshot_trees... done
check_snapshots... done
check_subvols... done
check_subvol_children... done
delete_dead_snapshots... done
check_inodes... done
check_extents... done
check_indirect_extents... done
check_dirents... done
check_xattrs... done
check_root... done
check_subvolume_structure... done
check_directory_structure... done
check_nlinks... done
resume_logged_ops... done
delete_dead_inodes... done
shutdown complete, journal seq 3303260
invalid bkey u64s 6 type accounting 0:9:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:12:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:15:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:16:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:17:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
invalid bkey u64s 6 type accounting 0:19:6 len 0 ver 0: btree btree=(unknown) 0
  accounting key with version=0: delete?, fixing
889f1a1a-d5ff-48d4-ab9e-915e2fc16798: errors fixed