Provided by: btrfs-progs_6.2-1_amd64 
NAME
btrfs-inspect-internal - query various internal information
SYNOPSIS
btrfs inspect-internal <subcommand> <args>
DESCRIPTION
This command group provides an interface to query internal information. The functionality
ranges from a simple UI to an ioctl or a more complex query that assembles the result from
several internal structures. The latter usually requires calls to privileged ioctls.
SUBCOMMAND
dump-super [options] <device> [device...]
Show btrfs superblock information stored on given devices in textual form. By
default the first superblock is printed, more details about all copies or
additional backup data can be printed.
Besides verification of the filesystem signature, there are no other sanity checks.
The superblock checksum status is reported, the device item and filesystem UUIDs
are checked and reported.
NOTE:
The meaning of option -s has changed in version 4.8 to be consistent with other
tools to specify superblock copy rather the offset. The old way still works, but
prints a warning. Please update your scripts to use --bytenr instead. The option
-i has been deprecated.
Options
-f|--full
print full superblock information, including the system chunk array and
backup roots
-a|--all
print information about all present superblock copies (cannot be used
together with -s option)
-i <super>
(deprecated since 4.8, same behaviour as --super)
--bytenr <bytenr>
specify offset to a superblock in a non-standard location at bytenr, useful
for debugging (disables the -f option)
If there are multiple options specified, only the last one applies.
-F|--force
attempt to print the superblock even if a valid BTRFS signature is not
found; the result may be completely wrong if the data does not resemble a
superblock
-s|--super <bytenr>
(see compatibility note above)
specify which mirror to print, valid values are 0, 1 and 2 and the
superblock must be present on the device with a valid signature, can be used
together with --force
dump-tree [options] <device> [device...]
Dump tree structures from a given device in textual form, expand keys to human
readable equivalents where possible. This is useful for analyzing filesystem state
or inconsistencies and has a positive educational effect on understanding the
internal filesystem structure.
NOTE:
Contains file names, consider that if you're asked to send the dump for
analysis. Does not contain file data.
Options
-e|--extents
print only extent-related information: extent and device trees
-d|--device
print only device-related information: tree root, chunk and device trees
-r|--roots
print only short root node information, i.e. the root tree keys
-R|--backups
same as --roots plus print backup root info, i.e. the backup root keys and
the respective tree root block offset
-u|--uuid
print only the uuid tree information, empty output if the tree does not
exist
-b <block_num>
print info of the specified block only, can be specified multiple times
--follow
use with -b, print all children tree blocks of <block_num>
--dfs (default up to 5.2)
use depth-first search to print trees, the nodes and leaves are intermixed
in the output
--bfs (default since 5.3)
use breadth-first search to print trees, the nodes are printed before all
leaves
--hide-names
print a placeholder HIDDEN instead of various names, useful for developers
to inspect the dump while keeping potentially sensitive information hidden
This is:
• directory entries (files, directories, subvolumes)
• default subvolume
• extended attributes (name, value)
• hardlink names (if stored inside another item or as extended references in
standalone items)
NOTE:
Lengths are not hidden because they can be calculated from the item size
anyway.
--csum-headers
print b-tree node checksums stored in headers (metadata)
--csum-items
print checksums stored in checksum items (data)
--noscan
do not automatically scan the system for other devices from the same
filesystem, only use the devices provided as the arguments
-t <tree_id>
print only the tree with the specified ID, where the ID can be numerical or
common name in a flexible human readable form
The tree id name recognition rules:
• case does not matter
• the C source definition, e.g. BTRFS_ROOT_TREE_OBJECTID
• short forms without BTRFS_ prefix, without _TREE and _OBJECTID suffix,
e.g. ROOT_TREE, ROOT
• convenience aliases, e.g. DEVICE for the DEV tree, CHECKSUM for CSUM
• unrecognized ID is an error
inode-resolve [-v] <ino> <path>
(needs root privileges)
resolve paths to all files with given inode number ino in a given subvolume at
path, i.e. all hardlinks
Options
-v (deprecated) alias for global -v option
logical-resolve [-Pvo] [-s <bufsize>] <logical> <path>
(needs root privileges)
resolve paths to all files at given logical address in the linear filesystem space
Options
-P skip the path resolving and print the inodes instead
-o ignore offsets, find all references to an extent instead of a single block.
Requires kernel support for the V2 ioctl (added in 4.15). The results might
need further processing to filter out unwanted extents by the offset that is
supposed to be obtained by other means.
-s <bufsize>
set internal buffer for storing the file names to bufsize, default is 64KiB,
maximum 16MiB. Buffer sizes over 64Kib require kernel support for the V2
ioctl (added in 4.15).
-v (deprecated) alias for global -v option
map-swapfile [options] <file>
(needs root privileges)
Find device-specific physical offset of file that can be used for hibernation. Also
verify that the file is suitable as a swapfile. See also command btrfs filesystem
mkswapfile and the Swapfile feature description.
NOTE:
Do not use filefrag or FIEMAP ioctl values reported as physical, this is
different due to internal filesystem mappings. The hibernation expects offset
relative to the physical block device.
Options
-r|--resume-offset
print only the value suitable as resume offset for file
/sys/power/resume_offset
min-dev-size [options] <path>
(needs root privileges)
return the minimum size the device can be shrunk to, without performing any resize
operation, this may be useful before executing the actual resize operation
Options
--id <id>
specify the device id to query, default is 1 if this option is not used
rootid <path>
for a given file or directory, return the containing tree root id, but for a
subvolume itself return its own tree id (i.e. subvol id)
NOTE:
The result is undefined for the so-called empty subvolumes (identified by inode
number 2), but such a subvolume does not contain any files anyway
subvolid-resolve <subvolid> <path>
(needs root privileges)
resolve the absolute path of the subvolume id subvolid
tree-stats [options] <device>
(needs root privileges)
Print sizes and statistics of trees. This takes a device as an argument and not a
mount point unlike other commands.
NOTE:
In case the the filesystem is still mounted it's possible to run the command but
the results may be inaccurate or various errors may be printed in case there are
ongoing writes to the filesystem. A warning is printed in such case.
Options
-b Print raw numbers in bytes.
EXIT STATUS
btrfs inspect-internal 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 documentation at
https://btrfs.readthedocs.io or wiki http://btrfs.wiki.kernel.org for further information.
SEE ALSO
mkfs.btrfs(8)