Btrfs-progs =========== Userspace utilities to manage btrfs filesystems. License: GPLv2. Btrfs is a copy on write (COW) filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration. This repository hosts following utilities and also documentation: * **btrfs** — the main administration tool ([manual page](https://btrfs.readthedocs.io/en/latest/btrfs.html)) * **mkfs.btrfs** — utility to create the filesystem ([manual page](https://btrfs.readthedocs.io/en/latest/mkfs.btrfs.html)) * all-in-one binary in the busybox style with mkfs.btrfs, btrfs-image and other tools built-in ([standalone tools](https://btrfs.readthedocs.io/en/latest/btrfs.html#standalone-tools)) * **libbtrfsutil** (LGPL v2.1) — C and python 3 bindings, see [libbtrfsutil/README.md](libbtrfsutil/README.md) for more * manual pages and documentation source published at [btrfs.readthedocs.io](https://btrfs.readthedocs.io) (RTD) See [INSTALL](INSTALL) for build instructions and [tests/README.md](tests/README.md) for testing information. Release cycle ------------- The major version releases are time-based and follow the cycle of the linux kernel releases. The cycle usually takes 2 months. A minor version releases may happen in the meantime if there are bug fixes or minor useful improvements queued. The release tags are signed with a GPG key ID `F2B4 1200 C54E FB30 380C 1756 C565 D5F9 D76D 583B`, release tarballs are hosted at [kernel.org](https://www.kernel.org/pub/linux/kernel/people/kdave/btrfs-progs/). See file [CHANGES](CHANGES) or [changelogs on RTD](https://btrfs.readthedocs.io/en/latest/CHANGES.html). Reporting bugs -------------- There are several ways, each has its own specifics and audience that can give feedback or work on a fix. The following list is sorted in the order of preference: * [github issue tracker](https://github.com/kdave/btrfs-progs/issues) * to the mailing list *linux-btrfs@vger.kernel.org* -- (not required to subscribe), beware that the mail might get overlooked in other traffic * IRC (irc.libera.chat #btrfs) -- good for discussions eg. if a bug is already known, but reports could miss developers' attention * please don't use https://bugzilla.kernel.org for btrfs-progs bugs Development ----------- The development takes place in the mailing list (*linux-btrfs@vger.kernel.org*) or at github (issues, pull requests). Changes should be split to logical parts if possible, documentation may be included in the same patch as to code or separately. The development model of btrfs-progs shares a lot with the kernel model. The * **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 * proper **subject line**: eg. prefix with _btrfs-progs: subpart, ..._ , descriptive yet not too long, see `git log --oneline` for some inspiration * 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 is not mandatory for less significant changes (typos, documentation) but is desired as this documents who authored the change, you can read more about the [The Developer's Certificate of Origin (chapter 11)](https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin) * if you are not used to the signed-off style, your contributions won't be rejected just because of it's missing, the _Author:_ tag will be added as a substitute in order to allow contributions without much bothering with formalities Source code coding style and preferences follow the [kernel coding style](https://www.kernel.org/doc/html/latest/process/coding-style.html). You can find the editor settings in `.editorconfig` and use the [EditorConfig](https://editorconfig.org/) plugin to let your editor use that, or update your editor settings manually. Testing ------- The testing documentation can be found in [tests/](tests/README.md) and continuous integration/container images in [ci/](ci/README.md). Documentation updates --------------------- Documentation fixes or updates do not need much explanation so sticking to the code rules in the previous section is not necessary. GitHub pull requests are OK, patches could be sent to me directly and not required to be also in the mailinglist. Pointing out typos via IRC also works, although might get accidentally lost in the noise. Documentation sources are written in [RST](https://en.wikipedia.org/wiki/ReStructuredText) and built by sphinx. Third-party sources ------------------- Build dependencies are listed in [INSTALL](INSTALL). Implementation of checksum/hash functions is provided by copies of the respective sources to avoid adding dependencies that would make deployments in rescue or limited environments harder. The implementations are portable and there are optimized versions for some architectures. Optionally it's possible to use libgcrypt, libsodium or libkcapi implementations. * CRC32C: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/ * XXHASH: https://github.com/Cyan4973/xxHash * SHA256: https://tools.ietf.org/html/rfc4634 * BLAKE2: https://github.com/BLAKE2/BLAKE2 Some other code is borrowed from kernel, eg. the raid5 tables or data structure implementation (list, rb-tree). References ---------- * [Documentation](https://btrfs.readthedocs.io) * [Manual pages](https://btrfs.readthedocs.io/en/latest/man-index.html) * [Changes -- brfs-progs](https://btrfs.readthedocs.io/en/latest/CHANGES.html) * [Features by kernel version](https://btrfs.readthedocs.io/en/latest/Feature-by-version.html)