INT 2F U - NETWORK REDIRECTOR (DOS 3.x only) - LOCK REGION OF FILE
AX = 110Ah
BX = file handle
CX:DX = starting offset
SI = high word of size
STACK: WORD low word of size
ES:DI -> SFT
SFT DPB field -> DPB of drive containing file
SS = DOS DS
Return: CF set on error
AL = DOS error code (see INT 21/AH=59h)
STACK unchanged
Notes:  called by DOS 3.10-3.31 kernel
the redirector is expected to resolve lock conflicts
SeeAlso: INT 21/AH=5Ch

See also: 2F110B

2F110A - NETWORK REDIRECTOR (DOS 3.x only) - LOCK REGION OF FILE