IRP_MJ_SET_EA (FS and filter drivers)
When Sent
The I/O Manager sends the IRP_MJ_SET_EA request to set a file's extended attributes.
Operation: File System Drivers
If the file system supports extended attributes, the file system driver should process the request and complete the IRP. Otherwise, the file system driver should return STATUS_EAS_NOT_SUPPORTED.
Operation: Legacy File System Filter Drivers
The filter driver should pass this IRP down to the next-lower driver on the stack.
Parameters
A file system or filter driver calls IoGetCurrentIrpStackLocation for the given IRP to get a pointer to its own stack location in the IRP. In the following parameters, Irp points to the IRP and IrpSp points to the IO_STACK_LOCATION. The driver can use the information that is set in the following members of the IRP and the IRP stack location to process a set extended attributes request:
DeviceObject is a pointer to the target device object.
Irp->AssociatedIrp.SystemBuffer points to a system-supplied input buffer that contains the extended attribute information to be set. Used for METHOD_BUFFERED I/O.
Irp->IoStatus points to an IO_STATUS_BLOCK structure that receives the final completion status and information about the requested operation.
Irp->MdlAddress is the address of a memory descriptor list (MDL) describing an input buffer that receives the extended attribute information. Used for METHOD_DIRECT I/O.
Irp->UserBuffer points to a caller-supplied FILE_FULL_EA_INFORMATION-structured input buffer that receives the extended attribute information. Used for METHOD_NEITHER I/O.
IrpSp->FileObject points to the file object that is associated with DeviceObject.
The IrpSp->FileObject parameter contains a pointer to the RelatedFileObject field, which is also a FILE_OBJECT structure. The RelatedFileObject field of the FILE_OBJECT structure isn't valid during the processing of IRP_MJ_SET_EA and shouldn't be used.
IrpSp->MajorFunction is set to IRP_MJ_SET_EA.
IrpSp->Parameters.SetEa.Length is the length in bytes of the input buffer.