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FsRtlUpperOplockFsctrl function (ntifs.h)

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The FsRtlUpperOplockFsctrl routine processes opportunistic lock (oplock) requests and acknowledgments for secondary, or layered, file systems. The upper file system submits the state of the oplock held in the lower file system. FsRtlUpperOplockFsctrl will determine whether to grant or deny the upper file system oplock.

Syntax

NTSTATUS FsRtlUpperOplockFsctrl(
  [in] POPLOCK Oplock,
  [in] PIRP    Irp,
  [in] ULONG   OpenCount,
  [in] ULONG   LowerOplockState,
  [in] ULONG   Flags
);

Parameters

[in] Oplock

An opaque oplock pointer for the file. This pointer must have been initialized by a previous call to FsRtlInitializeOplock.

[in] Irp

A pointer to the IRP for the I/O operation.

[in] OpenCount

Number of user handles for the file, if an exclusive oplock is being requested. Setting a nonzero value for a level 2, R, or RH oplock request indicates that there are byte-range locks on the file. For more information about oplock types, see Types of Oplocks.

[in] LowerOplockState

The value the lower oplock level held by the upper file system. This a bitwise OR combination of the following:

Value Meaning
OPLOCK_LEVEL_CACHE_READ Indicates an oplock Read (R) type.
OPLOCK_LEVEL_CACHE_WRITE Indicates an oplock Write (W) type.
OPLOCK_LEVEL_CACHE_HANDLE Indicates an oplock Handle (H) type.

[in] Flags

A bitmask for the associated oplock operations. A file system or filter driver sets bits to specify the behavior of FsRtlUpperOplockFsctrl. The Flags parameter has the following options:

Value Meaning
OPLOCK_FSCTRL_FLAG_ALL_KEYS_MATCH (0x00000001) The file system verified that all oplock keys on any currently open handles match. By specifying this flag, you allow the oplock package to grant an oplock of level RW or RWH when more than one open handle to the file exists.

Return value

FsRtlUpperOplockFsctrl returns one of the following NTSTATUS values:

Return code Description
STATUS_SUCCESS For an IRP_MJ_CREATE request, STATUS_SUCCESS indicates that the requested filter opportunistic lock (oplock) was granted. For a FSCTL operation, the meaning of STATUS_SUCCESS depends on the FSCTL code. For more information, see the Remarks section in FsRtlOplockFsctrlEx.
STATUS_CANCELLED The I/O operation was canceled. STATUS_CANCELLED is an error code.
STATUS_INVALID_PARAMETER The FSCTL code for the I/O operation was not a valid values oplock request. Valid request types are listed in the Remarks section of FsRtlOplockFsctrlEx. STATUS_INVALID_PARAMETER is an error code.
STATUS_OPLOCK_NOT_GRANTED The oplock could not be granted. The level of the requested upper file system oplock is not valid for the oplock granted for the lower file system. STATUS_OPLOCK_NOT_GRANTED is an error code.
STATUS_PENDING Used only for FSCTL operations. The meaning of STATUS_PENDING depends on the FSCTL code. For more information, see the Remarks section in FsRtlOplockFsctrlEx. STATUS_PENDING is a success code.
STATUS_CANNOT_GRANT_REQUESTED_OPLOCK An oplock acknowledgement for a new oplock is not allowed. The level of the upper file system of lock is not valid for the lower file system oplock.

Requirements

Requirement Value
Minimum supported client Windows 8.1
Target Platform Universal
Header ntifs.h (include Ntifs.h)
Library NtosKrnl.lib
DLL NtosKrnl.exe
IRQL IRQL <= APC_LEVEL

See also

FsRtlCheckUpperOplock

FsRtlOplockFsctrlEx