Hi,
Can someone help me in understanding how MUP interacts with files in client
side cache for offline files?
If I understand it right, MUP will do a reparse with the path changed to
c:\windows\CSC.….
So if there is a min filter in the stack, its pre-create callback would be
called twice, once with the UNC path (i.e. \<>..) and again with the
“CSC” path.
Is that correct?
Thanks,
Atul
On 7/6/2011 9:34 AM, Atul Kabra wrote:
Hi,
Can someone help me in understanding how MUP interacts with files in
client side cache for offline files?If I understand it right, MUP will do a reparse with the path changed to
c:\windows\CSC.….
>
No, as of Vista and it may have changed in Win 7 but the csc name for
the file is NOT the same as the original file name. This is because the
csc folder is a flat name space hence they use a mangled name stored in
a database to store the local file content. Of course this database, or
whatever they use, is not exposed and therefore it is very difficult to
link a failed remote request to a local csc request.
Pete
–
Kernel Drivers
Windows File System and Device Driver Consulting
www.KernelDrivers.com
866.263.9295
Got it. Thanks Pete.
On Thu, Jul 7, 2011 at 12:24 AM, Peter Scott wrote:
>
>
> On 7/6/2011 9:34 AM, Atul Kabra wrote:
>
>> Hi,
>>
>> Can someone help me in understanding how MUP interacts with files in
>> client side cache for offline files?
>>
>> If I understand it right, MUP will do a reparse with the path changed to
>> c:\windows\CSC.….
>>
>>
> No, as of Vista and it may have changed in Win 7 but the csc name for the
> file is NOT the same as the original file name. This is because the csc
> folder is a flat name space hence they use a mangled name stored in a
> database to store the local file content. Of course this database, or
> whatever they use, is not exposed and therefore it is very difficult to link
> a failed remote request to a local csc request.
>
> Pete
>
> –
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> www.KernelDrivers.com
> 866.263.9295
>
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></http:>
Atul,
So when an application tries to write to a file with
\re-directed to
the CSC database?
On Thu, Jul 7, 2011 at 10:25 PM, Danilo Almeida wrote:
> Atul,
>
>
On 7/11/2011 12:23 AM, Atul Kabra wrote:
So when an application tries to write to a file with \> <file:> share\file_name, which is an “offline” file, does the
> i/o get re-directed to the CSC database?
>
No, it is redirected to a file in the CSC directory but the name of the
target CSC file is difficult to determine since it is retrieved from a
CSC database.
Pete
> On Thu, Jul 7, 2011 at 10:25 PM, Danilo Almeida > mailto:xxxxx> wrote:
>
> Atul,
>
> </mailto:xxxxx></file:>
Sorry, I realized I did not frame my question correctly.
I wanted to know 'how does the i/o get redirected between MUP and CSC"?
Somebody must be doing a reparsing from \server_name\file to the file in
CSC database.
On Mon, Jul 11, 2011 at 7:36 PM, Peter Scott wrote:
>
>
> On 7/11/2011 12:23 AM, Atul Kabra wrote:
>
>> So when an application tries to write to a file with \>> <file:> share\file_name, which is an “offline” file, does the
>>
>> i/o get re-directed to the CSC database?
>>
>>
> No, it is redirected to a file in the CSC directory but the name of the
> target CSC file is difficult to determine since it is retrieved from a CSC
> database.
>
> Pete
>
> On Thu, Jul 7, 2011 at 10:25 PM, Danilo Almeida >> mailto:xxxxx> wrote:
>>
>> Atul,
>>
>> </mailto:xxxxx></file:>
The “someone”, is the redirector itself. When you want to access an offline file, and there is no server connection, redirector calls ZwCreateFile on a local version of it.
On 7/11/2011 9:15 AM, xxxxx@volny.cz wrote:
The “someone”, is the redirector itself. When you want to access an offline file, and there is no server connection, redirector calls ZwCreateFile on a local version of it.
As pointed out above, this is the reason why filtering the requests to
CSC is difficult. If you are filtering both network and local shares
then on the network instance you will see an IO request go by to the
underlying file system. Before it completes you would see a request go
to a local CSC located file. Therefore you do not know at the time of
the CSC targeted request that the remote request has failed and there is
no supported method to understand which remote file the CSC targeted
request is satisfying.
Pete
–
Kernel Drivers
Windows File System and Device Driver Consulting
www.KernelDrivers.com
866.263.9295