Is naked reading of inode->i_size OK?

Is naked reading of inode->i_size OK?

[Charles Manning]

Reading through 2.6.23's vmtruncate() [mm/memory.c], I notice that vmtruncate 
reads inode->i_size directly and not through the i_size_read() wrapper. Is 
that OK?

Lower down the same function calls i_size_write() and the calling chain calls 
i_size_read() so why is i_size_read() not being used here?

int vmtruncate(struct inode * inode, loff_t offset)
{
        struct address_space *mapping = inode->i_mapping;
        unsigned long limit;

        if (inode->i_size < offset)
                goto do_expand;
 	...
}