file access problem with view file (F3) on Windows

[Torsten Steitz]

Hello Brian,

I have a process on Windows which tries to open an existing file:

hFile=CreateFile(fname,                       // lpFileName

                 FILE_APPEND_DATA |           // dwDesiredAccess

                  FILE_READ_DATA |            // needed to allow LockFileEx (FILE_APPEND_DATA only results in Access denied)

                  DELETE,

                 FILE_SHARE_READ |            // dwShareMode

                  FILE_SHARE_WRITE |

                  FILE_SHARE_DELETE,

                 &sa,                         // lpSecurityAttributes

                 OPEN_ALWAYS,                 // dwCreationDisposition

                 FILE_ATTRIBUTE_NORMAL,       // dwFlagsAndAttributes

                 nullptr);                    // hTemplateFile

As you can see, I require ‘DELETE’ access, as I might need to rename (or delete) the file.

If the file exists and is viewed with FC (F3),  CreateFile() fails with "The process cannot access the file because it is being used by another process”. I used sysinternals/procmon to look how FC opened the file. Well, I saw multiple calls to CreateFile() from FC but one showed the potential problem:

18:05:51,1577562 fcw.exe 2820 CreateFile C:\ccts\log\giError.log SUCCESS Desired Access: Generic Read, Disposition: Open, Options: Synchronous IO Non-Alert, Non-Directory File, Attributes: n/a, ShareMode: Read, Write, AllocationSize: n/a, OpenResult: Opened

The FILE_SHARE_DELETE flag is missing which prevents my open request with DELETE flag in dwDesiredAccess.

Attached is the log of procmon when I just press F3 to view the file, the file is opened several times, line 18 shows the one with the missing dwShareMode flag.

best regards

Torsten