Btrfs source repositories
Since 2.6.29-rc1, Btrfs has been included in the mainline kernel.
Warning, Btrfs evolves very quickly do not test it unless:
- You have good backups and you have tested the restore capability
- You have a backup installation that you can switch to when something breaks
- You are willing to report any issues you find
- You can apply patches and compile the latest btrfs code against your kernel (quite easy with git and dkms, see below)
- You acknowledge that btrfs may eat your data
- Backups! Backups! Backups!
Everyone tests with the latest btrfs code from git. Even the latest Linus kernel probably doesn't have the latest, so if you're really interested in using and testing btrfs, get btrfs from git. Distributions usually offer a way to install a kernel built from git.
btrfs-progs git repository
The sources of the userspace utilities can be obtained from these repositories:
- git://git.kernel.org/pub/scm/linux/kernel/git/kdave/btrfs-progs.git (gitweb access)
- git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git (gitweb access)
There are 2 repositories that get synced at the time of a release (announcement) and can be considered equal for non-development branches.
The master branch of the repositories is updated at the time of a release and is not used for development. This branch is never rebased.
Devleopment git repositories:
- git://github.com/kdave/btrfs-progs.git (web access)
- git://repo.or.cz/btrfs-progs-unstable/devel.git (web access)
The latest development branch is called devel. Contains patches that are reviewed or tested and on the way to the next release. When a patch is added to the branch, a mail notification is sent as a reply to the patch.
The git repositories on kernel.org are not used for development or integration branches.
Integration branches collect patches that may need public testing and are provided for conveniece to developers or users willing to test unstable version. The patches in these branches are not guaranteed to be merged. The branches are assembled from scratch and server more like a snapshots than stable bases for other development.
where YYYMMDD is the date of the branch.
To check out this repository, and select the latest branch, use:
git clone git://repo.or.cz/btrfs-progs-unstable/devel.git cd devel git checkout integration-YYYYMMDD
Mirror of the repository is at
and has the same layout as the previous repository.
Note that this branch can be rebased when there's good reason for that (adding Reported-by/Reviewed-by tags to the middle of the patch series) or if there's a change needed down the patch stack in general. The point is to keep the git history clean.
Note to GitHub users
The pull requests will not be accepted directly, the preferred way is to send patches to the mailinglist instead. You can link to a branch in any git repository if the mails do not make it to the mailinglist or for convenience.
The development model of btrfs-progs shares a lot with the kernel model. The github way is different in some ways. We, the upstream community, expect that the patches meet some criteria (often lacking in github contributions):
- proper subject line: eg. prefix with btrfs-progs: subpart, ... , descriptive yet not too long
- proper changelog: the changelogs are often missing or lacking explanation why the change was made, or how is something broken, what are user-visible effects of the bug or the fix, how does an improvement help or the intended usecase
- the Signed-off-by line: this document who authored the change, you can read more about the The Developer's Certificate of Origin here (chapter 11)
- one logical change per patch: eg. not mixing bugfixes, cleanups, features etc., sometimes it's not clear and will be usually pointed out during reviews
Administration and support tools
There is a separate repository of useful scripts for common administrative tasks on btrfs. This is at:
btrfs kernel module git repository
Until October 2012, the latest features and bug fixes hit this repo before going upstream to Linus' kernel tree. Currently it is not up to date. The Linux RCs are more up to date and btrfs-next (see below) is most up to date.
btrfs repository (the command downloads a complete Linux kernel tree, if you have a local instance already, add it as a git remote) (Gitweb access)
Integration repository (btrfs-next)
Josef Bacik maintains an "integration" branch of all the kernel patches seen on the mailing list.
This is often the code you want to test if you think you've found a bug or want to test the latest features. Check the git log for the fs/btrfs to check which is up-to-date - in case one tree has fallen behind e.g.
https://git.kernel.org/cgit/linux/kernel/git/mason/linux-btrfs.git/log/fs/btrfs (use the drop-down at the far top-right of this window to check the different branches which Chris maintains - the latest code is normally not on 'master').
In an effort to be a little bit better about reviewing patches sent to the mailinglist I've created a btrfs-next git tree kernel.org. You can get it here
I'm going to be scraping the mailinglist every day for patches that are sent and applying them to this tree in order to get some better testing throughout the development cycle and possibly stop being such a lazy bum about reviewing. If you are looking to get patches into the next merge window and you notice I haven't included them in this tree please let me know so I can pull them in, I did a very casual look through the list to find stuff so I probably missed something. Thanks much,
Patches sent to mailinglist
A convenient interface to get an overview of patches and the related mail discussions can be found at https://patchwork.kernel.org/project/linux-btrfs/list/ .
It is possible to directly apply a patch by pasting the mbox link from the patch page to the command
$ wget -O - 'https://patchwork.kernel.org/patch/123456/mbox' | git am -
you may want to add --reject, or decide otherwise what to do with the patch.
Before compiling the userspace tools you'll need to get some dependencies:
yum install libuuid-devel libattr-devel zlib-devel libacl-devel e2fsprogs-devel libblkid-devel lzo2-devel asciidoc xmlto
Note that some Fedora/Red Hat derived distributions use lzo-devel instead of lzo2-devel.
sudo apt-get install asciidoc xmlto --no-install-recommends
Followed by either of:
sudo apt-get build-dep btrfs-tools -or- sudo apt-get install uuid-dev libattr1-dev zlib1g-dev libacl1-dev e2fslibs-dev libblkid-dev liblzo2-dev
If you tried the first and get "cannot find llzo2", or "blkid/blkid.h: No such file or directory" try the second; your distro has an even older version of btrfs-progs packaged than expected.
pacman -S e2fsprogs
zypper in libattr-devel zlib-devel libacl-devel libext2fs-devel libuuid-devel libblkid-devel lzo-devel asciidoc xmlto
Once you have everything in place, you can run
./autogen.sh ./configure make
to build the user-space tools. After that they can be used like this:
./btrfs fi show