[Help] How to Replace File Operations in File System?

freeman freeman.zhang1992 at gmail.com
Mon Feb 17 23:34:36 EST 2014


> Hi
>
> The operations will not change back until your object gets destroyed,
> whatever be the type of the object.
>
> Caching will not cause any issue here.
>
> Maybe if you can send the code we can have a look at it.
>
>
> -- 
> Regards,
> Rishi Agrawal
Hi Rishi,

It's very nice of you willing to help check my code!
I'm now very excited - problem solved!

I spent half a day beautifying my code yesterday (so that it won't annoy
you
that much), and find there is a problem:

Every time there is a read/write system call, I saved the lower file ops
and
address space ops. In their replacement(upper operations), I invoked
lower ones.
There's a possibility that it might saved the upper operations as lower
ones if I
open them twice in a short time. At this point, upper operation invoke
itself!
So I check the operations before truly save and replace them and, it works!

Thanks to you and all the amazing people in this amazing list that
helped me,
now I get both wrapfs and my own non-filesystem module functional for my
future work on transparent encryption, and most importantly, I've
learned and
enjoyed a lot!

Regards
Freeman Zhang



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