F2FS Preparing Support For Atomic Replace

A new feature being worked on for the Flash-Friendly File-System (F2FS) is the ability to atomically replace files.

Google engineer Daeho Jeong has been working on the new F2FS_IOC_START_ATOMIC_REPLACE ioctl for atomically replacing the entire contents of a file.

Daeho Jeong sums it up in the patch as:

Introduce a new ioctl to replace the whole content of a file atomically, which means it induces truncate and content update at the same time. We can start it with F2FS_IOC_START_ATOMIC_REPLACE and complete it with F2FS_IOC_COMMIT_ATOMIC_WRITE. Or abort it with F2FS_IOC_ABORT_ATOMIC_WRITE.

This new F2FS atomic replace ioctl is currently being vetted via the F2FS dev-test repository. There is also a F2FS-Tools patch for supporting the atomic replace ioctl with the f2fs_io_write command.

We'll see if this F2FS_IOC_START_ATOMIC_REPLACE makes it to "dev" and ends up being part of the changes sent in for the F2FS file-system with the upcoming Linux 6.1 merge window.