Installation instructions
=========================

The Btrfs utility programs require the following libraries/tools to build:

- util-linux (>= 2.24)
  - libblkid - block device id library
  - libmount - access /proc information about mount points
- libuuid - provided by util-linux, e2fsprogs/e2fslibs or libuuid
- liblzo2 - LZO data compression library
- zlib - ZLIB data compression library
- libzstd - ZSTD data compression library version >= 1.0.0

For the btrfs-convert utility:

- e2fsprogs - ext2/ext3/ext4 file system libraries, or called e2fslibs
- libreiserfscore - reiserfs file system library version >= 3.6.27

Optionally, the checksums based on cryptographic hashes can be implemented by
external libraries. Builtin implementations are provided in case the library
dependencies are not desired.

- libgcrypt
- libsodium
- libkcapi

Generating documentation:

- asciidoc - text document format tool
- xmlto - text document format tool
- source-highlight - optional, only for generating HTML output

XATTR library should be provided by the standard C library or by

- libattr - extended attribute library

Please note that the package names may differ according to the distribution.
See https://btrfs.wiki.kernel.org/index.php/Btrfs_source_repositories#Dependencies .


Building from sources
---------------------

To build from git sources you need to generate the configure script using the
autotools:

    $ ./autogen.sh

To build from the released tarballs:

    $ ./configure
    $ make
    $ make install

To install the libbtrfsutil Python bindings:

    $ make install_python

You may disable building some parts like documentation, btrfs-convert or
backtrace support. See ./configure --help for more.

Specific CFLAGS or LDFLAGS should be set like

    $ CFLAGS=... LDFLAGS=... ./configure --prefix=/usr

and not as arguments to make. You can specify additional flags to build via
variables EXTRA_CFLAGS and EXTRA_LDFLAGS that get appended to the predefined
values of the respective variables. There are further build tuning options
documented in the Makefile.

    $ make EXTRA_CFLAGS=-ggdb3

The build utilizes autotools, dependencies for generating the configure
scripts are:

* autoconf, autoheader
* automake, aclocal
* pkg-config


Statically built binaries
-------------------------

The makefiles are ready to let you build static binaries of the utilities. This
may be handy in rescue environments. Your system has to provide static version
of the libraries.

    $ make static
    $ make btrfs.static
    $ make btrfs-convert.static

The resulting binaries have the '.static' suffix, the intermediate object
files do not conflict with the normal (dynamic) build.


All-in-one binary (busybox style)
---------------------------------

Since version 5.2 it's possible to build a single binary that can act as other
standalone tools, based on the file name:

    $ make btrfs.box
    $ mv btrfs.box btrfs
    $ ln -s btrfs mkfs.btrfs

The list of built-ins can be obtained by

    $ btrfs help --box

The basic set will always contain: mkfs.btrfs, btrfs-image, btrfs-convert.


References:
* https://btrfs.wiki.kernel.org
