FsRtlSetupAdvancedHeaderEx2 macro (ntifs.h)

Article
09/30/2021

The FsRtlSetupAdvancedHeaderEx2 macro is used by file systems to initialize an FSRTL_ADVANCED_FCB_HEADER structure for use with stream and file contexts.

Syntax

void FsRtlSetupAdvancedHeaderEx2(
   _advhdr,
   _fmutx,
   _fctxptr,
   _aepushlock
);

Parameters

_advhdr

Pointer to the FSRTL_ADVANCED_FCB_HEADER structure to be initialized.

_fmutx

Pointer to an initialized fast mutex that will be used to synchronize access to certain FSRTL_ADVANCED_FCB_HEADER members. The fast mutex must be allocated from nonpaged pool. This parameter is optional and can be NULL. Callers should set this parameter to NULL if they intend to use an already existing fast mutex object. If FastMutex is NULL, the caller must explicitly set the FastMutex member of the FSRTL_ADVANCED_FCB_HEADER structure, contained in the stream context object, to point to the existing fast mutex. (This can be done before or after calling FsRtlSetupAdvancedHeaderEx2.)

_fctxptr

A pointer to a pointer field used by the file system runtime library (FSRTL) to track file contexts. This parameter is optional and can be NULL. If FileContextSupportPointer is not NULL, FileContextSupportPointer must be a pointer to a PVOID variable inside a per-file structure for the file system that created the structure. To indicate that the file system driver does not support file contexts, callers must set FileContextSupportPointer to NULL.

_aepushlock

Pointer to an opaque structure used to initialize the AePushLock field of the advanced header. The caller of this function is responsible for first allocating and initializing the memory for this field by calling FsRtlAllocateAePushLock, and subsequently freeing the memory by calling FsRtlFreeAePushLock. See FSRTL_ADVANCED_FCB_HEADER for more information about auto-expand push locks.

Return value

None

Remarks

File systems use the FsRtlSetupAdvancedHeaderEx2 macro to initialize an FSRTL_ADVANCED_FCB_HEADER structure for use with stream and file contexts.

When the advanced FCB header structure is no longer required, the file system must call FsRtlTeardownPerStreamContexts to free all associated stream and file context structures.

For more information, see Tracking Per-Stream Context in a Legacy File System Filter Driver.

Requirements

Requirement	Value
Minimum supported client	Windows 10, version 20H2
Header	ntifs.h