OverlayFS Proposed For The Linux 3.18 Kernel

After years of development, more than two dozen versions of the file-system, and real-world deployments in some Linux distributions, OverlayFS is trying again to get in the mainline Linux kernel.

OverlayFS is a simple union file-system already used by some live DVD/USB Linux distributions like Mageia and OpenWRT. OverlayFS has been trying for years to get mainlined in the Linux kernel but not all kernel developers have been happy with it -- some objecting it's incomplete, not happy with the design, etc.

Miklos Szeredi as the lead developer of OverlayFS has been persistent in going through many kernel reviews with the latest code now being up to "version 24" after years of development. Last year it looked like OverlayFS would come to Linux 3.10~3.11 but it never made it. Miklos is now pressing for it to be in the Linux 3.18 kernel.

Those wishing to learn more about the technicals of OverlayFS can see the kernel documentation.

Szeredi sent out another message this morning to the LKML, "I'd like to propose overlayfs for inclusion into 3.18. Al, would you mind giving it a review?" In the past, Al Viro, the VFS maintainer for the kernel, has been against OverlayFS. We'll see if this time if the stars align and allow OverlayFS to be integrated -- back during the 3.10 days Linus expressed interest in seeing it added. At least OverlayFS exhibits more mainline potential than Reiser4 and Tux3...