[ilyt]

> I wonder if there is still a limit with modern Linux OSes

Since filesystems introduced dynamic inode count it hasn't really been a problem. I remember ages ago you had to format filesystem in certain way if you wanted a lots of small files (say news or email server), but the need of that went away with better filesystems and growing storage sizes.

> and that is why Google is limiting some of their users?

On their side it's most likely on the number of entries in database, which usually is more than just storage cost.