However, I think it is a mistake to put the hooks in for syncfs and
not implement syncfs for other file systems that need it. From what
you say, syncfs() would be a no-op for those other file systems which
is (usually) wrong. Perhaps they could just call fsync() from
sync()? Doing nothing would be an error.
If that is true, then you might want to open an issue. Or perhaps
just add to https://github.com/apache/nuttx/issues/3399
Actually it won't "do nothing." It should return EBADF if the syncfs()
method is not provided. But that is error too. That is not the
correct return value. EBADF should signify "/fd/ is not a valid file
descriptor." which is not the case here. It should return ENOTSUP
