Small flush on monotone board? tricky line by villian

[linuxrocks]

I was really confused after the flop re-raise. He is clearly repping a small flush. Comments on what he might have and my play? He seems like a good TAG with 22/17/2.

PokerStars No-Limit Hold'em, $4 BB (5 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

UTG ($400)
MP ($163)
linuxrocks ($442)
SB ($396)
BB ($400)

Preflop: linuxrocks is Button with K[img]/images/graemlins/spade.gif[/img], J[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">1 fold</font>, MP calls $4, linuxrocks calls $4, SB completes, BB checks.

Flop: ($16) J[img]/images/graemlins/spade.gif[/img], 6[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">SB bets $12</font>, BB folds, MP calls $12, <font color="#CC3333">linuxrocks raises to $56</font>, <font color="#CC3333">SB raises to $140</font>, MP folds, linuxrocks calls $84.

Turn: ($308) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
SB checks, linuxrocks checks.

River: ($308) 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $100</font>, linuxrocks folds.

Final Pot: $308