Linux non-fuse read/write kernel driver for the exFAT, FAT12, FAT16 and vfat (FAT32) file systems.
Originally ported from Android kernel v3.0.

Kudos to ksv1986 for the mutex patch!
Thanks to JackNorris for being awesome and providing the clear_inode() patch.

Big thanks to lqs for completing the driver!
Big thanks to benpicco for fixing 3.11.y compatibility!

Special thanks to github user AndreiLux for spreading the word about the leak!

make
sudo make install

To load the driver manually, run this as root:

modprobe exfat

You may also specify custom toolchains by using CROSS_COMPILE flag, in my case:

CROSS_COMPILE=../dorimanx-SG2-I9100-Kernel/android-toolchain/bin/arm-eabi-

Let's take [linux] as the path to your kernel source dir...

cd [linux]
cp -rvf exfat-nofuse [linux]/fs/exfat

edit [linux]/fs/Kconfig

 menu "DOS/FAT/NT Filesystems"

  source "fs/fat/Kconfig"
 +source "fs/exfat/Kconfig"
  source "fs/ntfs/Kconfig"
  endmenu

edit [linux]/fs/Makefile

  obj-$(CONFIG_FAT_FS)    += fat/
 +obj-$(CONFIG_EXFAT_FS)  += exfat/
  obj-$(CONFIG_BFS_FS)    += bfs/

cd [linux]
make menuconfig

Go to:

File systems > DOS/FAT/NT check exfat as MODULE (M) (437) Default codepage for exFAT (utf8) Default iocharset for exFAT

ESC to main menu Save an Alternate Configuration File ESC ESC

build your kernel

Have fun.

You can have even more fun with exfat-nofuse by installing it as a DKMS module has the main advantage of being auto-compiled (and thus, possibly surviving) between kernel upgrades.

First, get dkms. On Ubuntu this should be:

sudo apt install dkms

Then copy the root of this repository to /usr/share:

sudo cp -R . /usr/src/exfat-1.2.8 (or whatever version number declared on dkms.conf is)
sudo dkms add -m exfat -v 1.2.8

Build and load the module:

sudo dkms build -m exfat -v 1.2.8
sudo dkms install -m exfat -v 1.2.8

Now you have a proper dkms module that will work for a long time... hopefully.