Support for atomic block writes in Linux 6.13 (2025)
6 hours ago
- #Database Performance
- #Linux Kernel
- #Atomic Writes
- Linux 6.13 introduces atomic block writes to prevent data tearing in databases.
- Atomic writes require hardware support (NVMe/SCSI) and software stack updates (VFS, filesystem, block layer).
- Databases use double writes for consistency, which atomic writes can replace to improve performance.
- Current implementation supports single-block atomic writes via O_DIRECT and pwritev2() with RWF_ATOMIC flag.
- Filesystem block size must align with device constraints; ext4 limits block size to page size, while XFS supports larger blocks.
- statx() system call queries atomic-write capabilities, including min/max unit sizes and support flags.
- Future work includes multi-block atomic write support and broader filesystem integration.