Linux 6.17 Upgrades EXT4: File System Now Ready for Multi-Threaded Container Attacks

Linux 6.17 delivers an important yet subtle update for anyone working with files.

Linux 6.17 delivers an important yet subtle update for anyone working with files.
The new Linux 6.17 kernel includes significant improvements to the EXT4 file system, which will greatly enhance the performance of servers with a high number of CPU cores and containers. The changes involve data block allocation algorithms and fixes for working with large memory blocks.
Baokun Li, an engineer from Huawei, highlighted scalability issues in EXT4 when many containers are running simultaneously on modern servers. Performance analysis revealed that the bottleneck lies in the system that handles data block allocation and release within the file system. When many containers are active, they compete for access to this mechanism, which leads to a significant drop in performance.
Solving the problem required 18 separate patches, which underwent three rounds of thorough review by the Linux development community. These improvements are now officially included in the 6.17 kernel version.
The results are impressive — the speed of preallocating disk space for containers has increased dramatically, especially under heavy load. An added bonus is a significant reduction in file fragmentation, although free space fragmentation has slightly increased as a side effect.
These changes are especially important for cloud providers and companies that rely heavily on containerized applications. The EXT4 enhancements are the most notable part of the file system updates in Linux 6.17 and are expected to have a positive impact on server performance.
