FltOplockIsFastIoPossible function (fltkernel.h)

Article
02/22/2024

The FltOplockIsFastIoPossible routine checks a file's opportunistic lock (oplock) state to determine whether fast I/O can be performed on the file.

Syntax

BOOLEAN FLTAPI FltOplockIsFastIoPossible(
  [in] POPLOCK Oplock
);

Parameters

[in] Oplock

Opaque oplock pointer for the file. This pointer must have been initialized by a previous call to FltInitializeOplock.

Return value

FltOplockIsFastIoPossible returns FALSE if there are outstanding oplocks on the file that prevent fast I/O from being performed; TRUE otherwise.

Remarks

FltOplockIsFastIoPossible determines whether fast I/O can be performed on a file, according to the following conditions:

If the Oplock parameter is NULL, or if the value of **Oplock* is NULL, there are no outstanding oplocks on the file, and fast I/O can be performed on the file.
If an exclusive oplock was granted for the file, but no oplock break is in progress, fast I/O can be performed on the file.

For detailed information about opportunistic locks, see the Windows SDK documentation.

Requirements

Requirement	Value
Target Platform	Universal
Header	fltkernel.h (include Fltkernel.h)
Library	FltMgr.lib
DLL	Fltmgr.sys
IRQL	<= APC_LEVEL