David Sterba said in a Linux kernel email announcement this Monday: The Btrft file system update has now landed on the Linux 5.15 mainline, which contains some exciting new features and improvements. This summer, the development team has been busy preparing a series of very active changes for Linux 5.15 and finally merged it into Linux 5.15 Git today.
Update Log:
- Support the FS-VERITY kernel layer, allowing transparent integrity and authenticity protection of read-only files. Previously, this function has been applied to EXT4 and F2FS, and now it is also applicable to the Btrfs file system.
- Supports IDMAPPED mounting, and allows the same file or directory with different ownerships to be disclosed. Design use cases cover everything from containers to system-home. This feature debuted in Linux 5.12, but it was only available for FAT and EXT4 file systems at the time.
- Btrfs ushered in the degenerated support for RAID0 and RAID10 modes. In the native Btrfs RAID generation mode, it can run on 1/2 devices, instead of 2/4 devices. While preserving the profile type, it helps users convert or remove devices from the array.
- Pre-reading code changes, supporting full transmission acceleration, and actual measurement can bring 11% performance improvement.
- Support batch delay to speed up the creation of many files.
- Support Fsync/tree-log acceleration, the throughput and running time of the sample workload are improved by 2%. Renamed lock contention is also lower, throughput is increased by 4%, and latency is reduced by 30%.
- Continue to develop sub-page support and experimental support for writing 64K page systems with 4K sectors.
- Improve the refresh logic, as well as other regular repairs and bottom-level enhancements.
