FUSE_SETLK / FUSE_SETLKW — fuse_lk_in (48 bytes). The
lk_flags & FUSE_LK_FLOCK (= 1) bit distinguishes whole-file
flock(2) semantics from POSIX byte-range fcntl(F_SETLK)
semantics. The same struct decodes both opcodes; the request
atom (:setlk vs :setlkw) tells the handler whether to block.
Summary
Types
@type t() :: %Wick.Protocol.Request.SetLk{ fh: non_neg_integer(), lk: Wick.Protocol.Request.FileLock.t(), lk_flags: non_neg_integer(), owner: non_neg_integer() }