On Sun, Feb 20, 2011 at 8:47 PM, kashish bhatia [off-list ref] wrote:

What exactly FIBMAP is? and how to use it ?

For instance , if I made my own module and I am using ioctl. Then how should
I use it?

FIBMAP is an ioctl. It is supposed to be called from a userspace
program. You can use it from userspace like this:

http://smackerelofopinion.blogspot.com/2009//fibmap-ioctl-file-system-block-number.html

If that is what you want to do, you can do the same thing from the
kernel, you can look up ioctl_fibmap in fs/ioctl.c and see if you get
what you need.

-Abhijit