Provided by: btrfs-tools_4.4-1ubuntu1.1_amd64 

NAME
btrfs-check - check or repair an unmounted btrfs filesystem
SYNOPSIS
btrfs check [options] <device>
DESCRIPTION
btrfs check is used to check or repair an unmounted btrfs filesystem.
Note
Since btrfs is under development, the btrfs check capabilities are continuously enhanced. It’s highly
recommended to read the following btrfs wiki before executing btrfs check with --repair option:
https://btrfs.wiki.kernel.org/index.php/Btrfsck
btrfsck is an alias of btrfs check command and is now deprecated.
OPTIONS
-s|--super <superblock>
use <superblock>th superblock copy, valid values are 0 up to 2 if the respective superblock offset is
within the fileystem
--repair
try to repair the filesystem
--init-csum-tree
create a new CRC tree and recalculate all checksums
--init-extent-tree
create a new extent tree
--check-data-csum
verify checkums of data blocks
-p|--progress
indicate progress at various checking phases
--qgroup-report
verify qgroup accounting and compare against filesystem accounting
--subvol-extents <subvolid>
show extent state for a subvolume
--tree-root <bytenr>
use the given bytenr for the tree root
EXIT STATUS
btrfs check returns a zero exit status if it succeeds. Non zero is returned in case of failure.
AVAILABILITY
btrfs is part of btrfs-progs. Please refer to the btrfs wiki http://btrfs.wiki.kernel.org for further
details.
SEE ALSO
mkfs.btrfs(8), btrfs-scrub(8), btrfs-rescue(8)
Btrfs v4.4 08/13/2019 BTRFS-CHECK(8)