RL-FlashFS with SD-Card: Work with directories?

If I look at all the f* / fs*-Functions, I wonder about the support of directories / subdirectories in FlashFS.

I know that we can do e.g. fopen ("M:\\Temp_Files\\Dump_file.log","w")
to create a file inside folder "Temp_Files".
I also knwo that we can do e.g. fdelete ("M:\\Working folder\\") /* Delete a folder, if empty. */
to delete a folder.

But how to create a folder?

And how to loop through the file system? - i.e. how to list all current folders? - Then list the content of a subfolder? How to find a file "xxxx.txt", which may be in root but may also be in /aaa/bbb/ccc/xxxx.txt? Does ffind do the job?

Thanks for the infos in advance.
A. Bader