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FltQueryInformationByName function (fltkernel.h)

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The FltQueryInformationByName routine returns the requested information about a named file.

Syntax

NTSTATUS FLTAPI FltQueryInformationByName(
  [in]           PFLT_FILTER               Filter,
  [in, optional] PFLT_INSTANCE             Instance,
  [in]           POBJECT_ATTRIBUTES        ObjectAttributes,
  [out]          PIO_STATUS_BLOCK          IoStatusBlock,
  [out]          PVOID                     FileInformation,
  [in]           ULONG                     Length,
  [in]           FILE_INFORMATION_CLASS    FileInformationClass,
  [in, optional] PIO_DRIVER_CREATE_CONTEXT DriverContext
);

Parameters

[in] Filter

Specifies the filter that is initiating this operation.

[in, optional] Instance

Specifies the instance towards which the create is targeted.

Important

Instance is not necessarily the initiating instance. It must match the instance towards which the create is targeted, if this parameter is non-NULL. If Instance is non-NULL, the current filter's pre-create callback is not called. The pre-callbacks start with the filter below the current filter.

[in] ObjectAttributes

Pointer to an [OBJECT_ATTRIBUTES] structure with the attributes to be used for the file object (for example, its name, SECURITY_DESCRIPTOR, etc.).

[out] IoStatusBlock

Pointer to an IO_STATUS_BLOCK structure containing the caller's I/O status block.

[out] FileInformation

Pointer to a structure that receives the requested information returned about the file. The type of structure is determined by FileInformationClass.

[in] Length

The length, in bytes, of the FileInformation buffer.

[in] FileInformationClass

A FILE_INFORMATION_CLASS enum value that specifies the type of information to return about the file. Can be one of the following values:

Value Type of structure that FileInformation points to
FileStatInformation FILE_STAT_INFORMATION
FileStatLxInformation **FILE_STAT_LX_INFORMATION
FileCaseSensitiveInformation FILE_CASE_SENSITIVE_INFORMATION. The caller must have opened the file with the FILE_READ_ATTRIBUTES flag specified in the DesiredAccess parameter. This value is available starting with Windows 10, version 1803.
FileCaseSensitiveInformationForceAccessCheck FILE_CASE_SENSITIVE_INFORMATION. This is a special version of the FileCaseSensitiveInformation operation that is used to force the IO Manager to perform access checks for the kernel-mode driver, similar to the checks that apply to a user-mode caller. This operation is only recognized by the IO Manager and a file system should never receive it. This value is available starting with Windows 10, version 1803.

[in, optional] DriverContext

A pointer to the driver's context space.

Return value

Returns STATUS_SUCCESS if the operation is successful. Otherwise, returns an appropriate NTSTATUS error code.

Remarks

This function returns requested information about a file without opening the actual file. The information returned is determined by the FileInformationClass that is specified, and it is placed into the caller's FileInformation buffer.

If Instance is non-NULL then the create will be targeted to the specified instance, calling all filters below the current filter before sending the I/O down. If Instance is NULL, the I/O will be always sent to the top of the filter stack.

Requirements

Requirement Value
Minimum supported client Windows 10, version 1706
Header fltkernel.h
Library FltMgr.lib
DLL Fltmgr.sys

See also

FILE_INFORMATION_CLASS