Allow MaxReadAhead to be set - fixes #139

fuse/api.go

@@ -43,6 +43,10 @@ type MountOptions struct {
 	// capped at the kernel maximum.
 	MaxWrite int
 
+	// Max read ahead to use.  If 0, use default. This number is
+	// capped at the kernel maximum.
+	MaxReadAhead int
+
 	// If IgnoreSecurityLabels is set, all security related xattr
 	// requests will return NO_DATA without passing through the
 	// user defined filesystem.  You should only set this if you

fuse/opcode.go

@@ -99,6 +99,9 @@ func doInit(server *Server, req *request) {
 		CongestionThreshold: uint16(server.opts.MaxBackground * 3 / 4),
 		MaxBackground:       uint16(server.opts.MaxBackground),
 	}
+	if server.opts.MaxReadAhead != 0 && uint32(server.opts.MaxReadAhead) < out.MaxReadAhead {
+		out.MaxReadAhead = uint32(server.opts.MaxReadAhead)
+	}
 	if out.Minor > input.Minor {
 		out.Minor = input.Minor
 	}