// Fill in the response that should be sent to the kernel, or set noResponse if
// the op requires no response.
func (c *Connection) kernelResponse(
m *buffer.OutMessage,
fuseID uint64,
op interface{},
opErr error) (noResponse bool) {
h := m.OutHeader()
h.Unique = fuseID
// Special case: handle the ops for which the kernel expects no response.
// interruptOp .
switch op.(type) {
case *fuseops.ForgetInodeOp:
noResponse = true
return
case *interruptOp:
noResponse = true
return
}
// If the user returned the error, fill in the error field of the outgoing
// message header.
if opErr != nil {
m.OutHeader().Error = -int32(syscall.EIO)
if errno, ok := opErr.(syscall.Errno); ok {
m.OutHeader().Error = -int32(errno)
}
// Special case: for some types, convertInMessage grew the message in order
// to obtain a destination buffer. Make sure that we shrink back to just
// the header, because on OS X the kernel otherwise returns EINVAL when we
// attempt to write an error response with a length that extends beyond the
// header.
m.ShrinkTo(buffer.OutMessageInitialSize)
}
// Otherwise, fill in the rest of the response.
if opErr == nil {
c.kernelResponseForOp(m, op)
}
h.Len = uint32(m.Len())
return
}
