Files Open with UNC Path May Be Closed Prematurely

• Microsoft Windows NT Workstation version 4.0
• Microsoft Windows NT Server version 4.0

SYMPTOMS

Files opened with a UNC name may be closed prematurely. This problem only occurs when a directory that is part of the UNC path is subsequently connected and then disconnected.

CAUSE

When the UNC file is opened, a tree ID is created by the server and is sent to the client Redirector. The tree ID represents the root or mount point on the server. In the above example, a tree ID will be returned for the directory dir. For file references, the Redirector includes the tree ID to tell the server where the path starts on the server. A tree ID has to be obtained before files can be accessed on the server. A tree ID is also needed to access a directory mapped to a drive letter. For optimization, the server will return the same tree ID for both accesses. The problem occurs on the net use /d. The Redirector will send a tree disconnect request to the server. This request closes all files in the tree, even files opened with UNC names.

RESOLUTION

To resolve this problem, obtain the following fix or wait for the next Windows NT service pack.

This fix should have the following time stamp:

   01/13/98  03:55                264,112 Rdr.sys (Intel)
   01/13/98  03:51                511,312 Rdr.sys (Alpha)

STATUS

Microsoft has confirmed this to be a problem in Windows NT version 4.0. A supported fix is now available, but has not been fully regression tested and should be applied only to systems experiencing this specific problem. Unless you are severely impacted by this specific problem, Microsoft recommends that you wait for the next Service Pack that contains this fix. Contact Microsoft Technical Support for more information.

Keywords          : kbbug4.00 kbfix4.00 NTSrvWkst
Version           : WinNT:4.0
Platform          : winnt
Issue type        : kbbug
Solution Type     : kbfix