This happened after adding these three new procfs entries:
fs/block
fs/mount
fs/usage
Of course, there is no directory fs in this case, only three files that have fs/ in their relative pathnames. The logic was detecting that fs was the name of the enty to report, but it was then declaring that fs was a file (because fs/block is of type file).
This was fixed by adding a check for matching lenghts. i.e., if strlen(fs) != strlen(fs/block), then report fs as a directory instead of a file.
ea13e24392