IoSizeOfIrp macro (ntifs.h)

The IoSizeOfIrp routine determines the size in bytes for an IRP, given the number of stack locations in the IRP.

Syntax

void IoSizeOfIrp(
   StackSize
);

StackSize

[in] Specifies the number of stack locations for the IRP.

None

IoSizeOfIrp returns the size, in bytes, of the IRP.

The input StackSize value is either that of the next-lower driver's device object or one more than that value.

Requirement	Value
Minimum supported client	Windows 2000
Target Platform	Desktop
Header	ntifs.h (include Wdm.h, Ntddk.h, Ntifs.h)
IRQL	Any level