register_filesystem(): Why does it return -EBUSY?

[Hareesh Nagarajan <hnagar2@gmail.com>]

If we have a look at the register_filesystem() function defined in 
fs/filesystems.c, we see that if a filesystem with a same name has 
already been registered then find_filesystem will return NON-NULL 
otherwise it will return NULL. So shouldn't 'res' be set to -EEXIST 
instead of -EBUSY? What is the reasoning behind register_filesystem 
returning -EBUSY for this particular condition?

int register_filesystem(struct file_system_type * fs) { ...
         struct file_system_type ** p;
	...
         p = find_filesystem(fs->name);
         if (*p)
                 res = -EBUSY; <-- Shouldn't this be -EEXIST?
         else
                 *p = fs;
	...
	return res;
}

Thanks,

Hareesh Nagarajan