zeroed data

NTFSD
1

Hello,

I am trying to read mass data from a disk by an application.
A file system is doing some manipulation on the data before sending it to the user (the filter was built by making some modifications to SFilter).
It is seems like when reading is very massive the cache manager starts to read from the filter ( the size of the data is larger than the one used by the application 4KB, or 64KB) and then after a while I do not get the correct data ( it is zeroed ).
I have tried to stop the FAST IO y returning FALSE once the callback function is called with no success.

Do you have any suggestions?

2

Hi,

does the problem disappear, when you undo your modifications to SFilter?

wrote news:xxxxx@ntfsd…
> Hello,
>
> I am trying to read mass data from a disk by an application.
> A file system is doing some manipulation on the data before sending it to
> the user (the filter was built by making some modifications to SFilter).
> It is seems like when reading is very massive the cache manager starts to
> read from the filter ( the size of the data is larger than the one used by
> the application 4KB, or 64KB) and then after a while I do not get the
> correct data ( it is zeroed ).
> I have tried to stop the FAST IO y returning FALSE once the callback
> function is called with no success.
>
> Do you have any suggestions?
>

3

Frank,

Thank you for the quick response,

It is a little bit more complicated: I am sending the SfRead requests to another thread using an MDL, which in response fills a buffer.
When reading big buffers 64KB there are no problems, but with small buffers after a while, there are data “loss”

Igal

4

What I am trying to ask is: are there any more mechanisms which read data from a storage beside the fastIO and the sfRead.
I mean once I return false on all fastIO functions ( I don’t want any fastIO activities) are all read requesting will go through the sfRead function or there some pathes which are out of my “sight”?

This is the only reason that I can think of that might cause incorrect data going up to the user application!

Igal