Provided by: btrfs-progs_6.6.3-1.2_amd64 bug

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.

SEE ALSO

       mkfs.btrfs(8)