fs/jbd2/Kconfig v3.0-rc7

JBD2

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.

JBD2_DEBUG

JBD2 (ext4) debugging support

If you are using the ext4 journaled file system (or
potentially any other filesystem/device using JBD2), this option
allows you to enable debugging output while the system is running,
in order to help track down any problems you are having.
By default, the debugging output will be turned off.

If you select Y here, then you will be able to turn on debugging
with "echo N > /sys/kernel/debug/jbd2/jbd2-debug", where N is a
number between 1 and 5. The higher the number, the more debugging
output is generated.  To turn debugging off again, do
"echo 0 > /sys/kernel/debug/jbd2/jbd2-debug".