Is vnode number also limit system-wide number of open file?

[Yubin Ruan]

I notice that there is a 
    
	unsigned long		i_ino;

in definition of `struct inode' [1], which is the virtual filesystem inode.
Does that mean "inode number" and is it used for indexing in the system-wide
inode table? 

If that is the case, would that limit the number of open file in Linux?

I know there *is* such a limit, and superusers can adjust that by
/proc/sys/fs/file-max. Currently I cannot raise that to too high, otherwise
the system would crash, which I think is because I have limited memory. But,
the point is, if I have lots of memory in my machine (say hunderds of
Gigabytes), would the number of open file system-wide limited by the `i_ino'
above? Since its type is "unsigned long", I guess I can only open
2^(sizeof(unsigned long)) file simultaneously? 

--
Yubin


[1]: http://elixir.free-electrons.com/linux/latest/source/include/linux/fs.h#L575