Sorry for bumping such an old thread. I had this issue just yesterday, messed with unmounting and remounting the mmc1 partition. Before remounting, even creating a new blank file with touch was impossible.
Remounted and tested again, could create files and symlinks, but as soon as I opened transmission, the file system entered on read only mode again.

I'm pretty sure that I've used transmission successfully before, but can't manage to use it again.