FLT_PARAMETERS for IRP_MJ_QUERY_EA union
Union component used when the MajorFunction field of the FLT_IO_PARAMETER_BLOCK structure for the operation is IRP_MJ_QUERY_EA.
Syntax
typedef union _FLT_PARAMETERS {
... ;
struct {
ULONG Length;
PVOID EaList;
ULONG EaListLength;
ULONG POINTER_ALIGNMENT EaIndex;
PVOID EaBuffer;
PMDL MdlAddress;
} QueryEa;
... ;
} FLT_PARAMETERS, *PFLT_PARAMETERS;
Members
QueryEa: Structure within FLT_PARAMETERS union containing the following members.
Length: Length, in bytes, of the buffer that EaBuffer points to.
EaList: Pointer to a caller-supplied, FILE_GET_EA_INFORMATION-structured input buffer specifying the extended attributes to be queried.
EaListLength: Length, in bytes, of the buffer that EaList points to.
EaIndex: Index of the entry at which to begin scanning the extended-attribute list. This parameter is ignored if the SL_INDEX_SPECIFIED flag is not set in the FLT_IO_PARAMETER_BLOCK structure for the operation or if EaList points to a nonempty list.
EaBuffer: Pointer to a caller-supplied, FILE_FULL_EA_INFORMATION-structured output buffer where the extended attribute values are to be returned. This member is optional and can be NULL if a MDL is provided in MdlAddress. See Remarks.
MdlAddress: Address of a memory descriptor list (MDL) describing the buffer that EaBuffer points to. This member is optional and can be NULL if a buffer is provided in EaBuffer. See Remarks.
Remarks
The FLT_PARAMETERS structure for IRP_MJ_QUERY_EA operations contains the parameters for an IRP-based query-extended-attributes-information operation represented by a callback data (FLT_CALLBACK_DATA) structure. It is contained in an FLT_IO_PARAMETER_BLOCK structure.
If both an EaBuffer and MdlAddress buffer are provided, it is recommended that minifilters use the MDL. The memory that EaBuffer points to is valid when it is a user mode address being accessed within the context of the calling process, or if it is a kernel mode address.
If a minifilter changes the value of MdlAddress, then after its post operation callback, Filter Manager will free the MDL currently stored in MdlAddress and restore the previous value of MdlAddress.
IRP_MJ_QUERY_EA is an IRP-based operation.
Requirements
| Requirement type | Requirement |
|---|---|
| Header | Fltkernel.h (include Fltkernel.h) |