I’ve been doing this too long and ported many drivers over to the
mini-filter model.
Pete
–
Kernel Drivers
Windows File System and Device Driver Consulting
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------ Original Message ------
From: xxxxx@hotmail.com
To: “Windows File Systems Devs Interest List”
Sent: 9/17/2015 6:05:48 PM
Subject: RE:[ntfsd] Time estimate to port legacy encryption driver
>Hi Pete, thanks for sharing your experience, I appreciate that. For
>just two months to finish porting a mini-filter driver, that is really
>fast. Are these encryption filter drivers?
>
>—
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That sounds about right; 2 months from start to ship.
ᐧ
On Thu, Sep 17, 2015 at 5:41 PM, Peter Scott
wrote:
>
> 5 months is a bit but I wouldn’t necessarily say it’s slow. Having done it
> several times, 1 month is about average to get it up and running and
> another month to get it stable, but this really depends on the initial
> implementation. Messy implementations can actually from scratch, taking
> much longer.
>
> Look at it from the perspective that now you can go back and fix all those
> little issues you were meaning to get back to some day.
>
> Pete
>
> –
> Kernel Drivers
> Windows File System and Device Driver Consulting
> www.KernelDrivers.com http:</http:>
> 866.263.9295
>
>
>
>
> ------ Original Message ------
> From: xxxxx@hotmail.com
> To: “Windows File Systems Devs Interest List”
> Sent: 9/16/2015 6:28:13 PM
> Subject: [ntfsd] Time estimate to port legacy encryption driver
>
> After attended Microsoft Plugfest in April 2015, I felt the urgency to
>> port our legacy file system encryption driver to mini-filter architecture.
>> I wrote a prototype of legacy encryption driver more than 10 years ago, and
>> it was incorporated into a product and actively maintained by another
>> developer.
>>
>> I volunteer to port the old driver to mini-filter architecture since
>> nobody has the time to do this porting. I did some mini-filter drivers
>> development in prototype quality previously but I involved in other
>> projects not related to file system or kernel driver past few years. This
>> time the porting effort has to be in production quality, and include all
>> the features implemented in the past 10 years from the legacy driver.
>>
>> So far I have spent about 5 months effort in mini-filter development
>> and porting. The differences other than new architecture, a lot of data
>> structures have to change, and I have to use new FltXXX functions instead
>> of building IRPs or ZwXXX functions. At the same time, I also do code
>> optimization, convert all strings to unicode strings instead of ansi,
>> enable verifier and WPP tracing, static code analysis, convert hash
>> table/link list to generic tables, etc. I found that the effort is not
>> simply copy & paste the old code to new mini-filter. I basically redo the
>> whole driver from the beginning and only refer to the old code for edge
>> conditions. I implemented each feature at a time, once completed, I tested
>> it against all file systems: NTFS, FAT32, exFAT and ReFS, and against all
>> local drives, network drive, RDP drive, remote shared drive, external
>> harddisk and thumbdrive. I use a list of known apps for reading/writing to
>> files, our internal file test tools, as well as Microsoft IFS Tests and
>> FileIO tests, to pass all tests.
>>
>> I would like to hear your experience of porting encryption filter driver
>> to mini-filter and the time you spent on the effort. After 5 months of
>> effort, I completed a prototype which can do all the above mentioned tasks,
>> but it is far from production quality as there are still a lot of features
>> to be put in the new driver. I don’t face major hurdles thanks to this
>> forum. My boss asked me when I can expect to finish the porting, and I told
>> him my raw estimate would be next April. Is my time being reasonable or am
>> I too slow in porting? Hope to hear some sharing from you guys.
>>
>> Regards,
>> Sinlam
>>
>>
>> —
>> NTFSD is sponsored by OSR
>>
>> OSR is hiring!! Info at http://www.osr.com/careers
>>
>> For our schedule of debugging and file system seminars visit:
>> http://www.osr.com/seminars
>>
>> To unsubscribe, visit the List Server section of OSR Online at
>> http://www.osronline.com/page.cfm?name=ListServer
>>
>
>
> —
> NTFSD is sponsored by OSR
>
> OSR is hiring!! Info at http://www.osr.com/careers
>
> For our schedule of debugging and file system seminars visit:
> http://www.osr.com/seminars
>
> To unsubscribe, visit the List Server section of OSR Online at
> http://www.osronline.com/page.cfm?name=ListServer
>
–
Jamey Kirby
Disrupting the establishment since 1964
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