FsRtlOplockIsFastIoPossible checks a file's opportunistic lock (oplock) state to determine whether fast I/O can be performed on the file.
- Oplock [in]
Opaque opportunistic lock pointer for the file. This pointer must have been initialized by a previous call to FsRtlInitializeOplock.
FsRtlOplockIsFastIoPossible returns FALSE if there are outstanding opportunistic locks on the file that prevent fast I/O from being performed; TRUE otherwise.
FsRtlOplockIsFastIoPossible 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 opportunistic locks on the file, and fast I/O can be performed on the file.
If an exclusive opportunistic lock 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 Microsoft Windows SDK documentation.
Minifilters should call FltOplockIsFastIoPossible instead of FsRtlOplockIsFastIoPossible.