CI status

Introduction

libblockdev is a C library supporting GObject introspection for manipulation of block devices. It has a plugin-based architecture where each technology (like LVM, Btrfs, MD RAID, Swap,...) is implemented in a separate plugin, possibly with multiple implementations (e.g. using LVM CLI or the new LVM DBus API).

Features

Following storage technologies are supported by libblockdev

• partitions
  • MSDOS, GPT
• filesystem operations
  • ext2, ext3, ext4, xfs, vfat, ntfs, exfat, btrfs, f2fs, nilfs2, udf
  • mounting
• LVM
  • thin provisioning, LVM RAID, cache, LVM VDO
• BTRFS
  • multi-device volumes, subvolumes, snapshots
• swap
• encryption
  • LUKS, TrueCrypt/VeraCrypt, BitLocker, FileVault2
  • integrity
  • SED OPAL
• DM (device mapper)
• loop devices
• MD RAID
• multipath
• s390
  • DASD, zFCP
• NVDIMM namespaces (deprecated)
• NVMe
• SMART

Architecture

The library itself is only a thin wrapper around a set of plugins, each for a particular technology listed above. The library provides an API consisting of sets of functions provided by its plugins. For example, there is a symbol/function called bd_lvm_lvcreate provided by the library which is dynamically loaded from the LVM plugin when the library's bd_init function will be called. Initially all those functions are no-ops just printing a warning on stderr and doing nothing. This way applications using the library won't crash, the operations just won't be run. Of course, the library has bd_is_plugin_available, which allows applications to check if something is provided/implemented or not.

Technologies behind the library

The library is written in C using the GLib library. The GLib library provides a lot of handy utilities that may be used by the library (no need for a new implementation of hash tables, lists, etc.) and moreover, it should be really easy to create bindings for the library via GObject introspection that works even with "not OOP" code. However, instead of returning links to structs (e.g. as a return value of the bd_lvm_vginfo function) it will return references to GObjects with attributes/properties and access methods. The reason is again an easy way to create bindings which we get for free.

License

The libblockdev code is licensed under LGPL 2.1 or later, see LICENSE for full text of the license.

Development

For developer documentation see README.DEVEL.md.

API documentation is available at https://storaged.org/libblockdev.

Branches and supported versions

The currently actively developed and supported version is 3.x on the main branch. New features should target this release.

The older 2.x version available on the 2.x-branch is still supported but new features are not planned for this release.