CONFIG_JBD2 (not configurable)

modulename: jbd2.ko

configname: CONFIG_JBD2

Linux Kernel Configuration
└─>File systems
└─>JBD2
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
This is a generic journaling layer for block devices that support
both 32-bit and 64-bit block numbers. It is currently used by
the ext4 and OCFS2 filesystems, but it could also be used to add
journal support to other file systems or block devices such
as RAID or LVM.

If you are using ext4 or OCFS2, you need to say Y here.
If you are not using ext4 or OCFS2 then you will
probably want to say N.

To compile this device as a module, choose M here. The module will be
called jbd2. If you are compiling ext4 or OCFS2 into the kernel,
you cannot compile this code as a module.

source code: