John Schneider Released from Jail After Five Hours Served

John Schneider's time in jail was about as long as a 'Lord of the Rings' movie ... thanks to overcrowding -- but he's got a lot to do to avoid going back.

We broke the story ... the 'Dukes of Hazzard' star was sentenced to 3 days in County lockup for failure to pay up more than $150k in back spousal support to his estranged wife. He checked in Tuesday morning and even posted a video as he drove there, encouraging fans to buy some of his gear.

According to law enforcement ... he checked in at 10:29 AM, and was out at 3:46 PM. Sounds like celebrity justice, but fact is, most non-violent offenders in L.A. County jail get severely shortened sentences due to jail overcrowding.

He's not in the clear yet, though. As we reported, Schneider still has to do 240 hours of community service, and complete a long list of financial obligations, or he'll get an additional 5-day sentence.