tw_cli.pl

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

sub sort_host {
	my ($n1,$n2);
	($n1)=$a=~/^host(\d+)$/ and ($n2)=$b=~/^host(\d+)$/ and return $n1 <=> $n2;
	return $a cmp $b;
}


our $SYS_unshare=272;      # /usr/include/asm/unistd_64.h
our $CLONE_NEWNS=0x20000;  # /usr/include/linux/sched.h

my $pid=fork;
defined $pid or die "$!\n";
unless ($pid) {
	opendir my $d,"/sys/class/scsi_host";
	my @names=sort sort_host grep !/^\.\.?$/,readdir $d;

	syscall($SYS_unshare,$CLONE_NEWNS) and die "$!\n";
	-d '/tmp/sysfs' or mkdir("/tmp/sysfs") or die "/tmp/sysfs: $!\n";
	system 'mount','-tsysfs','BLA','/tmp/sysfs' and exit 1;
	system 'mount','-ttmpfs','BLA','/sys/class/scsi_host' and exit 1;

	for my $name (reverse @names) {
		symlink("/tmp/sysfs/class/scsi_host/$name","/sys/class/scsi_host/$name") or die "/sys/class/scsi_host/$name: $!\n";
	}
	exec '/home/buczek/tw_cli/tw_cli.orig',@ARGV;
	die "$!\n";
}
wait;
$? and exit 1;