freeing disk block in 4.x kernel

[Siddharth Aggarwal]

Hi,

I am trying to find out where in the kernel code blocks on disk are freed. 
I want to track all the blocks freed on the disk as a result of file 
deletes etc., in my pseudo disk driver. 
Is there an equivalent of a blockfree() or something in the 4.x kernel 
code, where I can put a hook into my driver?

Thanks,
Sid.