FAST_IO_DISPATCH structure (wdm.h)

Contains a set of callback routines that a file system driver or file system filter driver (legacy) provides for fast I/O processing.

Syntax

typedef struct _FAST_IO_DISPATCH {
  ULONG                                  SizeOfFastIoDispatch;
  PFAST_IO_CHECK_IF_POSSIBLE             FastIoCheckIfPossible;
  PFAST_IO_READ                          FastIoRead;
  PFAST_IO_WRITE                         FastIoWrite;
  PFAST_IO_QUERY_BASIC_INFO              FastIoQueryBasicInfo;
  PFAST_IO_QUERY_STANDARD_INFO           FastIoQueryStandardInfo;
  PFAST_IO_LOCK                          FastIoLock;
  PFAST_IO_UNLOCK_SINGLE                 FastIoUnlockSingle;
  PFAST_IO_UNLOCK_ALL                    FastIoUnlockAll;
  PFAST_IO_UNLOCK_ALL_BY_KEY             FastIoUnlockAllByKey;
  PFAST_IO_DEVICE_CONTROL                FastIoDeviceControl;
  PFAST_IO_ACQUIRE_FILE                  AcquireFileForNtCreateSection;
  PFAST_IO_RELEASE_FILE                  ReleaseFileForNtCreateSection;
  PFAST_IO_DETACH_DEVICE                 FastIoDetachDevice;
  PFAST_IO_QUERY_NETWORK_OPEN_INFO       FastIoQueryNetworkOpenInfo;
  PFAST_IO_ACQUIRE_FOR_MOD_WRITE         AcquireForModWrite;
  PFAST_IO_MDL_READ                      MdlRead;
  PFAST_IO_MDL_READ_COMPLETE             MdlReadComplete;
  PFAST_IO_PREPARE_MDL_WRITE             PrepareMdlWrite;
  PFAST_IO_MDL_WRITE_COMPLETE            MdlWriteComplete;
  PFAST_IO_READ_COMPRESSED               FastIoReadCompressed;
  PFAST_IO_WRITE_COMPRESSED              FastIoWriteCompressed;
  PFAST_IO_MDL_READ_COMPLETE_COMPRESSED  MdlReadCompleteCompressed;
  PFAST_IO_MDL_WRITE_COMPLETE_COMPRESSED MdlWriteCompleteCompressed;
  PFAST_IO_QUERY_OPEN                    FastIoQueryOpen;
  PFAST_IO_RELEASE_FOR_MOD_WRITE         ReleaseForModWrite;
  PFAST_IO_ACQUIRE_FOR_CCFLUSH           AcquireForCcFlush;
  PFAST_IO_RELEASE_FOR_CCFLUSH           ReleaseForCcFlush;
} FAST_IO_DISPATCH, *PFAST_IO_DISPATCH;

Members

SizeOfFastIoDispatch

Set to sizeof(FAST_IO_DISPATCH).

FastIoCheckIfPossible

A pointer to a callback routine that checks if fast I/O is possible for a either a read or a write operation.

FastIoRead

A pointer to a callback routine that does a fast cached read, bypassing the IRP read path. It is used to perform a copy read for a cached file object.

FastIoWrite

A pointer to a callback routine that does a fast cached write, bypassing the IRP write path. It is used to perform a copy write for a cached file object.

FastIoQueryBasicInfo

A pointer to a callback routine for fast query of basic file information.

FastIoQueryStandardInfo

A pointer to a callback routine for fast query of standard file information.

FastIoLock

A pointer to a callback routine for doing a fast lock on a file object.

FastIoUnlockSingle

A pointer to a callback routine for doing a fast release of a single lock on a file object.

FastIoUnlockAll

A pointer to a callback routine for doing a fast release of a all locks held on a file object.

FastIoUnlockAllByKey

A pointer to a callback routine for doing a fast release of a all locks grouped by a key.

FastIoDeviceControl

A pointer to a callback routine for fast device control processing.

AcquireFileForNtCreateSection

A pointer to a callback routine used by the memory manager to acquire a file exclusively.

ReleaseFileForNtCreateSection

A pointer to a callback routine used by the memory manager to release a previously acquired file.

FastIoDetachDevice

A pointer to a callback routine that is invoked to detach the current device object from a device object that is being deleted.

FastIoQueryNetworkOpenInfo

A pointer to a callback routine for fast query of network file information.

AcquireForModWrite

A pointer to a callback routine that decides which file system resource the modified page writer should acquire and acquires it if possible.

MdlRead

A pointer to a callback routine that does a fast cached MDL read, bypassing the IRP read path. It is used to perform a copy read for a cached file object.

MdlReadComplete

A pointer to a callback routine that performs a fast completion of an MDL read.

PrepareMdlWrite

A pointer to a callback routine that does a fast cached MDL write, bypassing the IRP write path. It is used to perform a copy write for a cached file object.

MdlWriteComplete

A pointer to a callback routine that performs a fast completion of an MDL write.

FastIoReadCompressed

A pointer to a callback routine that performs a fast compressed read of data from a file.

FastIoWriteCompressed

A pointer to a callback routine that performs a fast compressed write of data to a file.

MdlReadCompleteCompressed

A pointer to a callback routine that completes a fast MDL compressed read of data from a file.

MdlWriteCompleteCompressed

A pointer to a callback routine that completes a fast MDL compressed write of data to a file.

FastIoQueryOpen

A pointer to a callback routine that implements a fast open for path based queries.

ReleaseForModWrite

This routine releases a file system resource previously acquired for the modified page write.

AcquireForCcFlush

A pointer to a callback routine that acquires a file system resource prior to a cache flush.

ReleaseForCcFlush

A pointer to a callback routine that releases a file system resource previously acquired for a cache flush.

Requirements

Requirement	Value
Header	wdm.h