[PLUG] What does _KERNEL macro mean?

[Ashutosh Adkar]

Hi,
         I have been looking into a lot of file system source code
lately.One thing I found but couldnt understand was that in the FS primary
header file
         we have definitions of structures like the superblock, inode and
directory entry.
         But after all the structure definitions what I saw almost every
where was the macro,
        "ifdef _KERNEL"

       What is this macro used for ?
       What does it mean?


        Thanks a lot





-- 
Regards,
Ashutosh Adkar