Facilitating the Spread of Knowledge and Innovation in Professional Software Development

Write for InfoQ


Choose your language

InfoQ Homepage News Microsoft Clears the Way for Having ExFAT in the Linux Kernel

Microsoft Clears the Way for Having ExFAT in the Linux Kernel

This item in japanese


Microsoft is making the official specification for exFAT file system freely available in a move meant to make it possible to include an exFAT driver directly into the Linux kernel. Additionally, when an exFAT-enabled Linux kernel is published, Microsoft will support its inclusion in the Open Invention Network’s Linux System Definition.

It’s important to us that the Linux community can make use of exFAT included in the Linux kernel with confidence. To this end, we will be making Microsoft’s technical specification for exFAT publicly available to facilitate development of conformant, interoperable implementations.

This decision provides the new possibility of making an exFAT driver part of the Linux kernel, which was previously impossible due to Microsoft's aggressive stance against Linux during the Ballmer era, and more recently to the non-inclusion of any exFAT-related patents into the patent non-aggression pact Microsoft signed when joining the Open Invention Network (OIN).

Instead, exFAT drivers have been available under Linux as FUSE modules, which means they run in userspace, or else they were implemented inside of the kernel but outside of the Linux mainline. This was the case for Android kernels, for example, but original equipment manufacturers (OEMs) were then obliged to license exFAT from Microsoft and pay the corresponding royalties.

Among the benefits of having exFAT available as a Linux kernel driver are its availability out-of-the-box, and better performance. According to Greg Kroah-Hartman, who submitted a patch to the Linux kernel adding support for exFAT, a kernel exFAT driver is much faster than its FUSE equivalent module. Specifically, FUSE modules have higher latency and worse input-output per second (IOPs), which is usually not a big issue on desktop-systems that have plenty of computing power and energy available but it is on embedded and IoT systems.

OIN is a mutual-defense organization that acquires patents and licenses them to its members for free. OIN members, in exchange, agree not to sue other members for their use of OIN patents in Linux-related systems. Presently, OIN has over 3,000 members, including major Linux distributions such as RedHat, Ubuntu, and SUSE. It is worth noting that neither Debian nor ArchLinux are listed among OIN members. Also, as OIN is exclusively Linux-oriented, the inclusion of exFAT in the OIN Linux System Definition will not foreseeably bring any benefits to FreeBSD and other *BSD OSes.

Rate this Article


Hello stranger!

You need to Register an InfoQ account or or login to post comments. But there's so much more behind being registered.

Get the most out of the InfoQ experience.

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Community comments

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p

Allowed html: a,b,br,blockquote,i,li,pre,u,ul,p