FUSE_FALLOCATE — fuse_fallocate_in (32 bytes). Wick doesn't
support sparse pre-allocation, so the session will reply
-ENOSYS regardless of the fields; we still parse the body so
decode-time validation works.
Summary
Types
@type t() :: %Wick.Protocol.Request.Fallocate{ fh: non_neg_integer(), length: non_neg_integer(), mode: non_neg_integer(), offset: non_neg_integer() }