fs/jbd/Kconfig v3.0-rc7

JBD

This is a generic journalling layer for block devices.  It is
currently used by the ext3 file system, 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 the ext3 file system, you need to say Y here.
If you are not using ext3 then you will probably want to say N.

To compile this device as a module, choose M here: the module will be
called jbd.  If you are compiling ext3 into the kernel, you
cannot compile this code as a module.

JBD_DEBUG

JBD (ext3) debugging support

If you are using the ext3 journaled file system (or potentially any
other file system/device using JBD), 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/jbd/jbd-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/jbd/jbd-debug".