Я не когда не проверял через btrfs check я проверял через scrub, а пишут, что через scrub "Примечание: Scrub не является средством проверки файловой системы (fsck) и не проверяет и не устраняет структурные повреждения в файловой системе. Он действительно проверяет только контрольные суммы данных и древовидных блоков, но не гарантирует, что содержимое древовидных блоков является действительным и согласованным. Существует некоторая проверка, выполняемая при считывании блоков метаданных с диска, но она не является обширной и не может заменить полный запуск проверки btrfs" У меня проверка через scrub показывает нет ошибок. Работает операционная система нормально.
https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-check
https://btrfs.wiki.kernel.org/index.php/Manpage/btrfs-scrub
"The filesystem checker is used to verify structural integrity of a filesystem and attempt to repair it if requested. It is recommended to unmount the filesystem prior to running the check, but it is possible to start checking a mounted filesystem (see --force).

By default, btrfs check will not modify the device but you can reaffirm that by the option --readonly.

btrfsck is an alias of btrfs check command and is now deprecated.

    Warning: Do not use --repair unless you are advised to do so by a developer or an experienced user, and then only after having accepted that no fsck successfully repair all types of filesystem corruption. Eg. some other software or hardware bugs can fatally damage a volume.

The structural integrity check verifies if internal filesystem objects or data structures satisfy the constraints, point to the right objects or are correctly connected together.

There are several cross checks that can detect wrong reference counts of shared extents, backreferences, missing extents of inodes, directory and inode connectivity etc.

The amount of memory required can be high, depending on the size of the filesystem, similarly the run time. Check the modes that can also affect that."

"btrfs scrub is used to scrub a mounted btrfs filesystem, which will read all data and metadata blocks from all devices and verify checksums. Automatically repair corrupted blocks if there’s a correct copy available.

    Note: Scrub is not a filesystem checker (fsck) and does not verify nor repair structural damage in the filesystem. It really only checks checksums of data and tree blocks, it doesn’t ensure the content of tree blocks is valid and consistent. There’s some validation performed when metadata blocks are read from disk but it’s not extensive and cannot substitute full btrfs check run.

The user is supposed to run it manually or via a periodic system service. The recommended period is a month but could be less. The estimated device bandwidth utilization is about 80% on an idle filesystem. The IO priority class is by default idle so background scrub should not significantly interfere with normal filesystem operation. The IO scheduler set for the device(s) might not support the priority classes though.

The scrubbing status is recorded in /var/lib/btrfs/ in textual files named scrub.status.UUID for a filesystem identified by the given UUID. (Progress state is communicated through a named pipe in file scrub.progress.UUID in the same directory.) The status file is updated every 5 seconds. A resumed scrub will continue from the last saved position.

Scrub can be started only on a mounted filesystem, though it’s possible to scrub only a selected device. See scrub start for more"