Re[2]: Iosolation Filter's Cache and System's Cache

As Rod pointed out, the approach here is to have only a single instance
of the data in the system cache. This instance is controlled by your FSD
and the underlying file system should never initialize a cache section
for the file. If you want to support multiple views, then you’ll
establish multiple SOPs accordingly in the IRP_MJ_CREATE handler.

For handling the consistency of a single cache instance, look through
the FastFAT code. This will point to places where you want to flush your
cache, purge it, etc. Of course your design may be slightly different
but it will provide you with the high level points of interaction.


Kernel Drivers
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------ Original Message ------
To: “Windows File Systems Devs Interest List”
Sent: 7/14/2016 11:22:26 PM
Subject: RE:[ntfsd] Iosolation Filter’s Cache and System’s Cache

>Thanks, rod.
>Your answer sure do me a great favor!
>There is one thing I still not very clear:
>If I created multiple SOPs in my Isolation Filter, I do could call Cc*
>Funtions towards any FileObject(on condition that my Isolation Filter
>maintains their SOPs), but the data cache coherency problem still
>exists, when and where should I tell some of the SOPs that their cached
>data is out-of-date? How could I tell them their cached data is
>out-of-date? CcFlushCache doesn’t make any sense, right? So it means I
>could only call CcPurgeCacheSection towards the out-of-date SOPs?
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