if ($fs =~ /^(?i)\/data\w+$/ || $fs =~ /^(?i)\/tmp\w+$/ ) {
[download]

The difference is the $fs after the ||. Your code compares the 2nd regex against $_.

If that doesn't do it, please show some examples of values of $fs.

Update: Here is a small example:

#!/usr/bin/env perl
use warnings;
use strict;

while (my $fs = <DATA>) {
    if ($fs =~ /^(?i)\/data\w+$/ || $fs =~ /^(?i)\/tmp\w+$/ ) {
        print "match: $fs";
    }
}

__DATA__
junk
/tmp
/tmpfoo
/data
/data2
/data again
junk2
[download]

This prints:

match: /tmpfoo
match: /data2
[download]