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MS-CIFS: Question on NT_TRANSACT_NOTIFY_CHANGE RRS feed

  • Question

  • I am currently experimenting on NT_TRANSACT_NOTIFY_CHANGE (server-side), and I ran into some 
    problems with Windows Vista clients. Windows Vista clients seem to hang (window freeze) upon
    issuing one NT_TRANSACT_NOTIFY_CHANGE request. This does not happen on my tests using
    other Windows clients (XP, 2003 server). Other clients have not yet been tested.
    Below are some details regarding my test environment setup:
    o client: WIndows Vista Ultimate (problem is reproducible with or without any service packs)
    o server: in-house
    The following are the steps I did for testing:
    1. Windows Vista client logs-on to the in-house server (IPC$)
    2. Windows Vista client accesses a specific share
    3. Windows Vista client tries to enter a folder directly under the share
    --> at this point, the client window is no longer responsive and the connection will timeout
    in a short while
    Based on our initial investigation, the following scenario occurred: (other details no longer
    included) (FIDs are only examples)
    1. Client logged-in and was able to connect to the share successfully.
    2. Client sent NT_CREATE_ANDX request to open base path (directly under share, path = "")
    Server was able to open the folder (fid: 0x0001)
    3. Client issued an NT_TRANSACT_NOTIFY_CHANGE request to the opened base path (fid: 0x0001)
    Server accepted the request. Since no updates have occurred since the request,
    server does not yet complete the request
    --> at this point, the client is still OK
    4. Client issued a number of Transaction2 requests to get information from the base path
    and its contents (TRANS2_QUERY_PATHINFO, TRANS2_QUERY_FILEINFO, TRANS2_FIND_FIRST2,
    TRANS2_FIND_NEXT2)
    Server was able to respond successfully to all Transaction2 requests
    5. Client sent NT_CREATE_ANDX request to open the folder under the share Server was able
    to open the folder (fid: 0x0002)
    6. Client sent another NT_CREATE_ANDX request to open the folder under the share
    Server was able to open the folder (fix: 0x0003)
    7. Client issued an NT_TRANSACT_NOTIFY_CHANGE request to the folder under the share
    Server accepted the request. Since no updates have occurred since the request,
    server does not yet complete the request
    --> at ths point, client seems to be waiting for something from the server,
    but there are actually no outstanding requests left to complete
    (aside from the Notify Change requests)
    8. Client terminates the connection due to timeout
    I did some experimenting on the server, and gathered the following additional information:
    o I tried to complete the NT_TRANSACT_NOTIFY_CHANGE request upon receipt from client,
    and the issue on Windows Vista client does not seem ot occur anymore
    * this means that the Windows Vista client was actually waiting for the NT_TRANSACT_NOTIFY_CHANGE request to complete
    * however, there are no updates yet on the folder, and (specs-wise) I cannot complete
    the transaction just yet
    The (almost) same scenario can be observed when the server is changed to Windows XP.
    However, the issue does not seem to occur. I'm pretty sure that the problem is in our
    in-house server, but I could not seem to find any leads on the issue.
    I'm kind of at lost on what the client is really expecting (no additional information on completion instances can be found on CIFS Technical Reference and MS-CIFS).
    Any (even vague) ideas/possible causes are welcome.
    I am very sorry for not being able to give enough information, as we are only currently
    relying on some debugging logs (we cannot sniff through our network, we are still working on this).
    Many thanks.
    Friday, June 4, 2010 4:37 AM

Answers

  • Kinpin,

     

    I would be happy to work with you on this issue, but I would like to discuss this offline.  I can be reached at bburgin at microsoft dot com.  I'm going to close this issue on my end.

     

     


    Bryan S. Burgin Senior Escalation Engineer Microsoft Protocol Open Specifications Team
    Tuesday, June 22, 2010 8:31 PM
    Moderator

All replies

  • Hi Kinpin,

    Thank you for your question regarding NT_TRANSACT_NOTIFY_CHANGE in the MS-CIFS open specification.  One of the Open Specifications team will contact you shortly.

    Best regards,
    Tom Jebo
    Senior Support Escalation Engineer
    Microsoft Open Specifications Team

    Friday, June 4, 2010 2:07 PM
  • Kinpin,

     

    I'm presently reseraching a similar issue.  Can you send me mail at bburgin at microsoft dot com offline so we can trade traces, etc.?

     

    Bryan S. Burgin
    Senior Escalation Engineer
    Microsoft Protocol Open Specifications Team

    Friday, June 4, 2010 4:18 PM
    Moderator
  • Kinpin,

    You mentioned that this was not happening on XP and Server 2003, but you did not test with other clients yet.  Did you get a chance to try this on Windows 7?  The other issue I'm looking into that is similar affects Windows Vista and Windows 7.  I'm debugging that issue using Windows 7.  I would like to discuss this offline with you if you could e-mail me at the address I provided in my previous post.

     

    Bryan S. Burgin
    Senior Escalation Engineer
    Microsoft Protocol Open Specifications Team

    Wednesday, June 9, 2010 9:07 PM
    Moderator
  • Kinpin,

     

    I would be happy to work with you on this issue, but I would like to discuss this offline.  I can be reached at bburgin at microsoft dot com.  I'm going to close this issue on my end.

     

     


    Bryan S. Burgin Senior Escalation Engineer Microsoft Protocol Open Specifications Team
    Tuesday, June 22, 2010 8:31 PM
    Moderator