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FSCTL_OPLOCK_BREAK_NOTIFY IOCTL (winioctl.h)

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Enables the calling application to wait for completion of an opportunistic lock break.

This operation is not useful to application developers and is documented here only for completeness. CreateFile handles the problem that this operation was designed to handle.

To perform this operation, call the DeviceIoControl function using the following parameters.

BOOL DeviceIoControl(
  (HANDLE) hDevice,             // handle to file
  FSCTL_OPLOCK_BREAK_NOTIFY,    // dwIoControlCode
  NULL,                         // lpInBuffer
  0,                            // nInBufferSize
  NULL,                         // lpOutBuffer
  0,                            // nOutBufferSize
  (LPDWORD) lpBytesReturned,    // number of bytes returned
  (LPOVERLAPPED) lpOverlapped   // OVERLAPPED structure
);

Remarks

This operation is used only by client applications that have requested an opportunistic lock from a local server. Client applications requesting opportunistic locks from remote servers must not request them directly—the network redirector transparently requests opportunistic locks for the application.

For the implications of overlapped I/O on this operation, see the Remarks section of the DeviceIoControl topic.

In Windows 8 and Windows Server 2012, this code is supported by the following technologies.

Technology Supported
Server Message Block (SMB) 3.0 protocol No
SMB 3.0 Transparent Failover (TFO) No
SMB 3.0 with Scale-out File Shares (SO) No
Cluster Shared Volume File System (CsvFS) Yes
Resilient File System (ReFS) Yes

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header winioctl.h (include Windows.h)

See also