Link2sd lost 2nd partition (f2fs)

While working with Link2sd, I moved a ton of apps to the SD's 2nd partition, using f2fs file system. Rebooting the phone (XT926 - 4.4.2 - rooted), the 2nd partition was no longer accessable and, of course, the apps vanished. Worse, I can't re-install some of them. I get the "not enough storage" gripe. Short of doing an FDR, is there any hope of recovering the data or at least making it possible to re-install the lost apps? FWIW, I tried reading the SD under Win7 (nothing found, of course) and SuSE Linux with f2fs.tools installed. Still nothing.

How SOL am I?