Rap mogul Irv Gotti is a hardcore New York Knicks fan -- and he didn't hold back when we asked how he felt about the Knicks striking out in free agency ...
"Man, F*ck Dolan!"
Yeah, he ain't happy.
Gotti -- along with a bunch of other Knicks fans -- are furious with owner James Dolan for not signing any of the marquee free agents up for grabs over the past few days.
He's especially upset about Kevin Durant -- who not only didn't sign with the Knicks, but inked a deal just down the way with the Brooklyn Nets.