Deleting a file based on disk ID

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清歌不尽
清歌不尽 2021-02-19 09:09

As described here, using SetFileInformationByHandle with FILE_DISPOSITION_INFO allows one to set a file with an open handle to be deleted upon all handles being closed.

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  •  北荒
    北荒 (楼主)
    2021-02-19 09:47

    In order to make FILE_DISPOSITION_INFO work you need to specify the DELETE access in the CreateFile function as reported in https://msdn.microsoft.com/en-us/library/windows/desktop/aa365539(v=VS.85).aspx:

    You must specify appropriate access flags when creating the file handle for use with SetFileInformationByHandle. For example, if the application is using FILE_DISPOSITION_INFO with the DeleteFile member set to TRUE, the file would need DELETE access requested in the call to the CreateFile function. To see an example of this, see the Example Code section. For more information about file permissions, see File Security and Access Rights. I.e.

    //...
      HANDLE hFile = CreateFile( TEXT("tempfile"), 
                                 GENERIC_READ | GENERIC_WRITE | DELETE,  //Specify DELETE access!
                                 0 /* exclusive access */,
                                 NULL, 
                                 CREATE_ALWAYS,
                                 0, 
                                 NULL);
    

    But it seems that an handle created with OpenFileById() cannot be used because the function cannot accept the DELETE flag.
    From https://msdn.microsoft.com/en-us/library/windows/desktop/aa365432(v=vs.85).aspx on OpenFileById() it can be read: dwDesired

    Access [in]
    The access to the object. Access can be read, write, or both.

    Even setting DELETE or GENERIC_ALL the function fails.
    If you replace the handle passed to SetFileInformationByHandle with one created with the CreateFile function having the DELETE flag set, as above, it works.

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