PC NT: 4,292,967,295 File Locks on .MMF and .CAL Files

• Microsoft Mail for PC Networks, versions 3.0 and 3.2

SYMPTOMS

When you view the file locks on a user's eight-digit hexadecimal ID .CAL or .MMF file from the Windows NT version 3.1 or 3.5 Control Panel (in the Control Panel window, choose the Server icon and then select the In Use button), you may see 4,292,967,295 file locks reported in the Locks field.

CAUSE

This problem occurs when the Mail client is installed on Windows 3.1 with the LAN Manager 2.x drivers and the postoffice is on Windows NT 3.1 or 3.5.

LAN Manager uses Lock&Read to do its locks and it uses Lock&X to do its unlocks. Windows NT increments and decrements the NumberOfLocks variable when a Lock&X is issued. Therefore, all unlocks are done within Lock&X, which decrements the variable, but all locks are done in Lock&Read, which doesn't touch the variable. This causes the fi3_num_locks value, as reported by SrvNetFileEnum, to be at -4 when the logon is complete.

This problem does not occur when Microsoft Mail is installed on a Windows 3.1 or 3.11 for Workgroups client.

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.