From 16def0fe3d383e4d3056b4f034a85c3f5f31552e Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Fri, 10 Jan 2014 08:27:48 +0000
Subject: [PATCH] scstadmin: Merge r4875:5189 from trunk

git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/2.2.x@5192 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scstadmin/Makefile                            |   50 +-
 scstadmin/init.d/scst                         |    3 +-
 scstadmin/scstadmin.procfs/Makefile           |   13 +-
 .../scst-0.8.22/lib/SCST/SCST.pm              |    2 +-
 scstadmin/scstadmin.spec.in                   |   80 +
 scstadmin/scstadmin.sysfs/Makefile            |   13 +-
 .../scst-0.9.10/lib/SCST/SCST.pm              | 3103 ++++++++---------
 .../scst-0.9.10/t/01-start-scst.t             |   27 +
 .../scst-0.9.10/t/02-scst-attr.t              |   46 +
 .../scst-0.9.10/t/03-targets.t                |  365 ++
 .../scstadmin.sysfs/scst-0.9.10/t/04-alua.t   |  143 +
 .../scst-0.9.10/t/05-dynattr.t                |  160 +
 .../scst-0.9.10/t/06-cont-on-err.t            |   67 +
 .../scst-0.9.10/t/99-stop-scst.t              |   21 +
 .../scst-0.9.10/t/after-restore.conf          |   56 +
 .../scst-0.9.10/t/to-be-restored.conf         |   62 +
 scstadmin/scstadmin.sysfs/scstadmin           |  618 ++--
 17 files changed, 3000 insertions(+), 1829 deletions(-)
 create mode 100644 scstadmin/scstadmin.spec.in
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/01-start-scst.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/02-scst-attr.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/03-targets.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/04-alua.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/05-dynattr.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/06-cont-on-err.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/99-stop-scst.t
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/after-restore.conf
 create mode 100644 scstadmin/scstadmin.sysfs/scst-0.9.10/t/to-be-restored.conf

diff --git a/scstadmin/Makefile b/scstadmin/Makefile
index f874bae06..53821b3a8 100644
--- a/scstadmin/Makefile
+++ b/scstadmin/Makefile
@@ -1,10 +1,21 @@
+ifndef PREFIX
+        PREFIX=/usr/local
+endif
+
+VERSION = $(shell echo -n "$$(sed -n 's/^[[:blank:]]*\$$VERSION[[:blank:]]*=[[:blank:]]*[\"'"'"']\([0-9.]*\)[\"'"'"'];$$/\1/p' scstadmin/scst-*/lib/SCST/SCST.pm).";	\
+		   if svn info >/dev/null 2>&1;				\
+		   then svn info | sed -n 's/^Revision:[[:blank:]]*/r/p';\
+		   else git show | sed -n 's/^commit[[:blank:]]*\(.......\).*/\1/p'; \
+		   fi)
+
 SCSTADMIN_DIR = $(shell if [ ! -h scstadmin ]; then		\
 			    rm -f scstadmin;			\
 			    ln -s scstadmin.sysfs scstadmin;	\
 			fi;					\
 			echo scstadmin)
 
-MANDIR := $(DESTDIR)/usr/local/man
+MANDIR ?= $(DESTDIR)$(PREFIX)/man
+
 INITDIR := $(shell if [ -f /etc/slackware-version ]; then	\
                      echo /etc/rc.d;				\
                    else						\
@@ -57,15 +68,12 @@ DEFAULTDIR := $(shell if [ -f /etc/gentoo-release ]; then	        \
 all:
 	cd $(SCSTADMIN_DIR) && $(MAKE) $@
 
-install:
+install install_vendor:
+	@if [ -z "$(DESTDIR)" ] && rpm -q scstadmin >/dev/null 2>&1; then \
+	echo Error: the scstadmin RPM must be uninstalled first; false; fi
 	@if ! perl -MExtUtils::MakeMaker -e '' >/dev/null 2>&1; then \
 	echo Error: the Perl module ExtUtils::MakeMaker must be installed \
 	first; false; fi
-	@if [ ! -e /etc/slackware-version -a ! -e /etc/gentoo-release	      \
-	      -a ! -e /lib/lsb/init-functions ]; then			      \
-	echo "Error: the lsb-core (Debian, Ubuntu), redhat-lsb (RHEL, CentOS,"\
-	"Scientific Linux, Fedora) or insserv (SLES, openSUSE) package must"  \
-	"be installed first"; false; fi
 	cd $(SCSTADMIN_DIR) && $(MAKE) $@
 	for m in scstadmin/man*/*.[1-9]; do				\
 	  if [ -e $$m ]; then						\
@@ -111,6 +119,34 @@ uninstall:
 perl-module:
 	cd $(SCSTADMIN_DIR) && $(MAKE) $@
 
+test:
+	$(MAKE) -C scstadmin test
+
+dist-gzip:
+	name=$(shell basename $$PWD) &&					\
+	mkdir $${name}-$(VERSION) &&					\
+	{ ../scripts/list-source-files | tar -T- -cf- |			\
+	  tar -C $${name}-$(VERSION) -xf-; } &&				\
+	rm -f $${name}-$(VERSION).tar.bz2 &&				\
+	tar -cjf $${name}-$(VERSION).tar.bz2 $${name}-$(VERSION) &&	\
+	rm -rf $${name}-$(VERSION)
+
+rpm:
+	name=$(shell basename $$PWD) &&					\
+	rpmtopdir="$$(if [ $$(id -u) = 0 ]; then echo /usr/src/packages;\
+		      else echo $$PWD/rpmbuilddir; fi)" &&		\
+	$(MAKE) dist-gzip &&						\
+	rm -rf $${rpmtopdir} &&						\
+	for d in BUILD RPMS SOURCES SPECS SRPMS; do			\
+	  mkdir -p $${rpmtopdir}/$$d;					\
+	done &&								\
+	cp $${name}-$(VERSION).tar.bz2 $${rpmtopdir}/SOURCES &&		\
+	sed "s/@rpm_version@/$(VERSION)/g"				\
+		<$${name}.spec.in >$${name}.spec &&			\
+	MAKE="$(MAKE)"							\
+	rpmbuild --define="%_topdir $${rpmtopdir}" -ba $${name}.spec &&	\
+	rm -f $${name}-$(VERSION).tar.bz2
+
 clean:
 	cd $(SCSTADMIN_DIR) && $(MAKE) $@
 
diff --git a/scstadmin/init.d/scst b/scstadmin/init.d/scst
index abeaa46e2..d4b1e4f33 100755
--- a/scstadmin/init.d/scst
+++ b/scstadmin/init.d/scst
@@ -79,6 +79,7 @@ fi
 cat <<"EOF"
 
 SCST_CFG=/etc/scst.conf
+ISCSI_DAEMON="$(which iscsi-scstd)"
 
 show_status() {
   _rc_status_ret=$?
@@ -159,7 +160,7 @@ parse_scst_conf() {
                 SCST_OPT_MODULES="crc32c-intel $SCST_OPT_MODULES";;
         esac
         SCST_OPT_MODULES="crc32c $SCST_OPT_MODULES"
-        SCST_DAEMONS="/usr/local/sbin/iscsi-scstd $SCST_DAEMONS"
+        SCST_DAEMONS="${ISCSI_DAEMON} $SCST_DAEMONS"
     fi
 }
 
diff --git a/scstadmin/scstadmin.procfs/Makefile b/scstadmin/scstadmin.procfs/Makefile
index 715fed166..5d7a4626f 100644
--- a/scstadmin/scstadmin.procfs/Makefile
+++ b/scstadmin/scstadmin.procfs/Makefile
@@ -1,12 +1,16 @@
+ifndef PREFIX
+        PREFIX=/usr/local
+endif
+
 MODULE_VERSION = 0.8.22
 TOOL = scstadmin
 
-SBINDIR := $(PREFIX)/usr/local/sbin
+SBINDIR := $(PREFIX)/sbin
 
 all: perl-module
 
-install: all
-	$(MAKE) -C scst-$(MODULE_VERSION) install
+install install_vendor: all
+	$(MAKE) -C scst-$(MODULE_VERSION) $@ DESTDIR=$(DESTDIR)
 	install -d $(DESTDIR)$(SBINDIR)
 	install -m 755 $(TOOL) $(DESTDIR)$(SBINDIR)
 
@@ -19,6 +23,9 @@ perl-module:
 	perl Makefile.PL;
 	$(MAKE) -C scst-$(MODULE_VERSION)
 
+test:
+	$(MAKE) -C scst-$(MODULE_VERSION) test
+
 clean:
 	-$(MAKE) -C scst-$(MODULE_VERSION) clean
 
diff --git a/scstadmin/scstadmin.procfs/scst-0.8.22/lib/SCST/SCST.pm b/scstadmin/scstadmin.procfs/scst-0.8.22/lib/SCST/SCST.pm
index 2533a9f30..e69905653 100644
--- a/scstadmin/scstadmin.procfs/scst-0.8.22/lib/SCST/SCST.pm
+++ b/scstadmin/scstadmin.procfs/scst-0.8.22/lib/SCST/SCST.pm
@@ -43,7 +43,7 @@ $IOTYPE_PHYSICAL    = 100;
 $IOTYPE_VIRTUAL     = 101;
 $IOTYPE_PERFORMANCE = 102;
 
-$VERSION = 0.8.22;
+$VERSION = '0.8.22';
 
 my $_SCST_MIN_MAJOR_   = 2;
 my $_SCST_MIN_MINOR_   = 0;
diff --git a/scstadmin/scstadmin.spec.in b/scstadmin/scstadmin.spec.in
new file mode 100644
index 000000000..e1c57cf7f
--- /dev/null
+++ b/scstadmin/scstadmin.spec.in
@@ -0,0 +1,80 @@
+%define rpm_version @rpm_version@
+%define make %{expand:%%(echo ${MAKE:-make})}
+
+Name:		scstadmin
+Version:        %{rpm_version}
+Release:        1
+Summary:	SCST configuration tool
+Group:		Productivity/Networking/Other
+License:	GPLv2
+Vendor:		http://scst.sourceforge.net/
+URL:		http://scst.sourceforge.net/
+
+Source:		%{name}-%{version}.tar.bz2
+BuildRoot:	%{_tmppath}/%{name}-%{version}-build
+AutoReqProv:	yes
+
+%description
+A tool for configuring SCST via the SCST sysfs interface. Allows to save,
+restore and modify any aspect of the SCST configuration. An extensive set of
+commands is available to modify any configurable parameter of target drivers,
+target ports, SCST devices, LUNs, initiator groups and ALUA configuration
+information.
+
+Authors:
+--------
+    Mark R. Buechler, Bart Van Assche and others
+
+%define scstadmin_perl_installvendorman3dir \
+  %(perl -V:installvendorman3dir | sed "s|.*='||;s|'.*||")
+%define scstadmin_perl_process_packlist \
+set -x;\
+if test -n "$RPM_BUILD_ROOT" -a -d $RPM_BUILD_ROOT%perl_vendorarch/auto; then \
+  find $RPM_BUILD_ROOT%perl_vendorarch/auto -name .packlist -print0 | \
+  xargs -0 -r rm; \
+  if [ %{_target_cpu} == noarch ]; then \
+      find $RPM_BUILD_ROOT%perl_vendorarch/auto -depth -type d -print0 | \
+      xargs -0 -r rmdir; \
+    fi; \
+  fi; \
+  rm -f $RPM_BUILD_ROOT%{perl_archlib}/perllocal.pod; set +x
+
+%prep
+
+%setup -q
+
+%build
+export PREFIX=%{_prefix} DESTDIR=%{buildroot} MANDIR=%{buildroot}%{_mandir}
+%{make}
+
+%install
+export PREFIX=%{_prefix} DESTDIR=%{buildroot} MANDIR=%{buildroot}%{_mandir}
+%{make} install_vendor
+%scstadmin_perl_process_packlist
+rm -rf %{buildroot}/var/adm/perl-modules/scst
+
+%clean
+rm -rf %{buildroot}
+
+%pre
+rm -f /usr/local/sbin/scstadmin
+rm -f /usr/local/man/man1/scstadmin.1*
+rm -f /usr/local/man/man3/SCST::SCST.3pm*
+rm -f /usr/local/man/man5/scst.5*
+rm -f /usr/local/man/man5/scst.conf.5*
+
+%files
+%defattr(-,root,root)
+%config(noreplace) /etc/default/scst
+/etc/init.d/scst
+%{_sbindir}/scstadmin
+%{perl_vendorlib}/SCST
+%{perl_vendorarch}/auto/SCST-SCST
+%{_mandir}/man1/scstadmin.1*
+%{scstadmin_perl_installvendorman3dir}/SCST::SCST.3pm*
+%{_mandir}/man5/scst.5*
+%{_mandir}/man5/scst.conf.5*
+
+%changelog
+* Fri Oct 04 2013 Bart Van Assche <bvanassche@acm.org>
+- Initial spec file.
diff --git a/scstadmin/scstadmin.sysfs/Makefile b/scstadmin/scstadmin.sysfs/Makefile
index a2ce58a60..d6e9ee34c 100644
--- a/scstadmin/scstadmin.sysfs/Makefile
+++ b/scstadmin/scstadmin.sysfs/Makefile
@@ -1,12 +1,16 @@
+ifndef PREFIX
+        PREFIX=/usr/local
+endif
+
 MODULE_VERSION = 0.9.10
 TOOL = scstadmin
 
-SBINDIR := /usr/local/sbin
+SBINDIR := $(PREFIX)/sbin
 
 all: perl-module
 
-install: all
-	$(MAKE) -C scst-$(MODULE_VERSION) install
+install install_vendor: all
+	$(MAKE) -C scst-$(MODULE_VERSION) $@ DESTDIR=$(DESTDIR)
 	install -d $(DESTDIR)$(SBINDIR)
 	install -m 755 $(TOOL) $(DESTDIR)$(SBINDIR)
 
@@ -19,6 +23,9 @@ perl-module:
 	perl Makefile.PL;
 	$(MAKE) -C scst-$(MODULE_VERSION)
 
+test:
+	$(MAKE) -C scst-$(MODULE_VERSION) test
+
 clean:
 	-$(MAKE) -C scst-$(MODULE_VERSION) clean
 
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/lib/SCST/SCST.pm b/scstadmin/scstadmin.sysfs/scst-0.9.10/lib/SCST/SCST.pm
index f519ddeed..dc2748c40 100644
--- a/scstadmin/scstadmin.sysfs/scst-0.9.10/lib/SCST/SCST.pm
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/lib/SCST/SCST.pm
@@ -143,6 +143,10 @@ SCST_C_DEV_GRP_EXISTS       => 121,
 SCST_C_DEV_GRP_ADD_FAIL     => 122,
 SCST_C_DEV_GRP_REM_FAIL     => 123,
 
+SCST_C_ALUA_BAD_ATTRIBUTES   => 125,
+SCST_C_ALUA_ATTRIBUTE_STATIC => 126,
+SCST_C_ALUA_SETATTR_FAIL     => 127,
+
 SCST_C_DGRP_ADD_DEV_FAIL    => 130,
 SCST_C_DGRP_REM_DEV_FAIL    => 131,
 SCST_C_DGRP_NO_DEVICE       => 132,
@@ -175,7 +179,7 @@ my %VERBOSE_ERROR = (
 (SCST_C_FATAL_ERROR)          => 'A fatal error occured. See "dmesg" for more information.',
 (SCST_C_BAD_ATTRIBUTES)       => 'Bad attributes given for SCST.',
 (SCST_C_ATTRIBUTE_STATIC)     => 'SCST attribute specified is static',
-(SCST_C_SETATTR_FAIL)         => 'Failed to set a SCST attribute. See "demsg" for more information.',
+(SCST_C_SETATTR_FAIL)         => 'Failed to set a SCST attribute. See "dmesg" for more information.',
 
 (SCST_C_HND_NO_HANDLER)       => 'No such handler exists.',
 (SCST_C_HND_BAD_ATTRIBUTES)   => 'Bad attributes given for handler.',
@@ -285,7 +289,7 @@ use vars qw(@ISA @EXPORT $VERSION);
 
 use vars qw($TGT_TYPE_HARDWARE $TGT_TYPE_VIRTUAL);
 
-$VERSION = 0.9.10;
+$VERSION = '0.9.10';
 
 $TGT_TYPE_HARDWARE = 1;
 $TGT_TYPE_VIRTUAL  = 2;
@@ -296,52 +300,82 @@ my $_SCST_MIN_MAJOR_   = 2;
 my $_SCST_MIN_MINOR_   = 0;
 my $_SCST_MIN_RELEASE_ = 0;
 
+my $_new_sysfs_interface;
 sub new_sysfs_interface {
-	return !(-d SCST_ROOT_OLD);
+	if (!defined($_new_sysfs_interface)) {
+		$_new_sysfs_interface = !(-d SCST_ROOT_OLD) ? TRUE : FALSE;
+	}
+	return $_new_sysfs_interface;
 }
 
+my $_scst_root_dir;
 sub SCST_ROOT_DIR {
-	return -d SCST_ROOT_OLD ? SCST_ROOT_OLD : SCST_ROOT_NEW;
+	if (!defined($_scst_root_dir)) {
+		$_scst_root_dir = (-d SCST_ROOT_OLD ? SCST_ROOT_OLD :
+				   SCST_ROOT_NEW);
+	}
+	return $_scst_root_dir;
 }
 
+my $_scst_sgv_dir;
 sub SCST_SGV_DIR {
-	return SCST_ROOT_DIR() . '/sgv'
+	if (!defined($_scst_sgv_dir)) {
+		$_scst_sgv_dir = SCST_ROOT_DIR() . '/sgv';
+	}
+	return $_scst_sgv_dir;
 }
 
+my $_scst_queue_res_path = "";
 sub SCST_QUEUE_RES_PATH {
-	return -d SCST_ROOT_OLD ? SCST_ROOT_OLD . '/' . SCST_QUEUE_RES : undef;
+	if ($_scst_queue_res_path eq "") {
+		$_scst_queue_res_path = (-d SCST_ROOT_OLD ?
+					 SCST_ROOT_OLD . '/' . SCST_QUEUE_RES :
+					 undef);
+	}
+	return $_scst_queue_res_path;
 }
 
 # Device handlers.
+my $_scst_handlers_dir;
 sub SCST_HANDLERS_DIR {
-	if (-d SCST_ROOT_OLD) {
-		return SCST_ROOT_OLD . '/' . SCST_HANDLERS;
-	} else {
-		return '/sys/bus/scst_tgt_dev/drivers';
+	if (!defined($_scst_handlers_dir)) {
+		$_scst_handlers_dir = (-d SCST_ROOT_OLD ?
+				       SCST_ROOT_OLD . '/' . SCST_HANDLERS :
+				       '/sys/bus/scst_tgt_dev/drivers');
 	}
+	return $_scst_handlers_dir;
 }
 
 # Device instances.
+my $_scst_devices_dir;
 sub SCST_DEVICES_DIR {
-	if (-d SCST_ROOT_OLD) {
-		return SCST_ROOT_OLD . '/' . SCST_DEVICES;
-	} else {
-		return '/sys/bus/scst_tgt_dev/devices';
+	if (!defined($_scst_devices_dir)) {
+		$_scst_devices_dir = (-d SCST_ROOT_OLD ?
+				      SCST_ROOT_OLD . '/' . SCST_DEVICES :
+				      '/sys/bus/scst_tgt_dev/devices');
 	}
+	return $_scst_devices_dir;
 }
 
 # Target drivers.
+my $_scst_targets_dir;
 sub SCST_TARGETS_DIR {
-	if (-d SCST_ROOT_OLD) {
-		return SCST_ROOT_OLD . '/' . SCST_TARGETS;
-	} else {
-		return '/sys/bus/scst_target/drivers';
+	if (!defined($_scst_targets_dir)) {
+		$_scst_targets_dir = (-d SCST_ROOT_OLD ?
+				      SCST_ROOT_OLD . '/' . SCST_TARGETS :
+				      '/sys/bus/scst_target/drivers');
 	}
+	return $_scst_targets_dir;
 }
 
 # ALUA Device groups.
+my $_scst_dev_group_dir;
 sub SCST_DEV_GROUP_DIR {
-	return make_path(SCST_ROOT_DIR(), SCST_DEV_GROUPS);
+	if (!defined($_scst_dev_group_dir)) {
+		$_scst_dev_group_dir = make_path(SCST_ROOT_DIR(),
+						 SCST_DEV_GROUPS);
+	}
+	return $_scst_dev_group_dir;
 }
 
 sub new {
@@ -380,7 +414,7 @@ sub new {
 sub scstVersion {
 	my $self = shift;
 
-	my $attributes = $self->scstAttributes();
+	my ($attributes, $errorString) = $self->scstAttributes();
 
 	return undef if (!defined($attributes));
 	return $$attributes{'version'}->{'value'};
@@ -393,8 +427,7 @@ sub scstAttributes {
 	my $pHandle = new IO::Handle;
 	my $_path = SCST_ROOT_DIR();
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "scstAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		return (undef, "scstAttributes(): Unable to read directory '$_path': $!");
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -420,23 +453,22 @@ sub scstAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "scsiAttributes(): Unable to read ".
-					  "scst attribute '$attribute': $!";
-					return undef;
+					return (undef, "scsiAttributes(): Unable to read ".
+					  "scst attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
-				chomp $value;
+				chomp $value if (defined($value));
 
 				my $is_key = <$io>;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -467,13 +499,24 @@ sub scstAttributes {
 						$attributes{$attribute}->{'value'} = $value;
 					}
 				}
+				close $io;
 
 				$attributes{$attribute}->{'static'} = $is_static;
 			}
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
+}
+
+sub setAttrFailed {
+	my $path = shift;
+	my $no_such_attr = shift;
+	my $is_static = shift;
+
+	return (-f $path) && (-r $path) ? $is_static : $no_such_attr;
 }
 
 sub setScstAttribute {
@@ -483,123 +526,116 @@ sub setScstAttribute {
 
 	return TRUE if (!defined($attribute) || !defined($value));
 
-	my $attributes = $self->scstAttributes();
-
-	return SCST_C_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
 	my $path = make_path(SCST_ROOT_DIR(), $attribute);
-
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_BAD_ATTRIBUTES,
+			     SCST_C_ATTRIBUTE_STATIC);
 }
 
+my @_drivers;
 sub drivers {
 	my $self = shift;
-	my @drivers;
 
-	my $dHandle = new IO::Handle;
-	my $_path = SCST_TARGETS_DIR();
-	if (!(opendir $dHandle, $_path)) {
-		$self->{'err_string'} = "drivers(): Unable to read directory '$_path': $!";
-		return undef;
-	}
+	if (!@_drivers) {
+		my $dHandle = new IO::Handle;
+		my $_path = SCST_TARGETS_DIR();
+		if (opendir $dHandle, $_path) {
+			foreach my $driver (readdir($dHandle)) {
+				next if (($driver eq '.') || ($driver eq '..'));
 
-	foreach my $driver (readdir($dHandle)) {
-		next if (($driver eq '.') || ($driver eq '..'));
-
-		if (-d make_path(SCST_TARGETS_DIR(), $driver)) {
-			push @drivers, $driver;
+				if (-d make_path(SCST_TARGETS_DIR(), $driver)) {
+					push @_drivers, $driver;
+				}
+			}
+			close $dHandle;
+		} else {
+			return (undef, "drivers(): Unable to read directory '$_path': $!");
 		}
 	}
 
-	close $dHandle;
-
-	return \@drivers;
+	return (\@_drivers, undef);
 }
 
 
 sub targets {
 	my $self = shift;
 	my $driver = shift;
-	my @targets;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "targets(): Driver '$driver' is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver));
 
 	my $tHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver);
-	if (!(opendir $tHandle, $_path)) {
-		$self->{'err_string'} = "targets(): Unable to read directory '$_path': $!";
-		return undef;
-	}
+	if (opendir $tHandle, $_path) {
+		my @targets;
 
-	foreach my $target (readdir($tHandle)) {
-		next if ($target eq '.' || $target eq '..' ||
-			 $target eq 'module');
+		foreach my $target (readdir($tHandle)) {
+			next if ($target eq '.' || $target eq '..' ||
+				 $target eq 'module');
 
-		if (-d make_path(SCST_TARGETS_DIR(), $driver, $target)) {
-			push @targets, $target;
+			if (-d make_path(SCST_TARGETS_DIR(), $driver,
+					 $target)) {
+				push @targets, $target;
+			}
 		}
+		close $tHandle;
+		@targets = sort(@targets);
+		return (\@targets, undef);
+	}
+	my $errorString;
+	if ($self->driverExists($driver) != TRUE) {
+		$errorString = "targets(): Driver '$driver' is not available";
+	} else {
+		$errorString = "targets(): Unable to read directory '$_path': $!";
 	}
 
-	close $tHandle;
-
-	return \@targets;
+	return (undef, $errorString);
 }
 
 sub groups {
 	my $self = shift;
 	my $driver = shift;
 	my $target = shift;
-	my @groups;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "groups(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "groups(): Target '$target' is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver) || !defined($target));
 
 	my $gHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 			      SCST_GROUPS);
-	if (!(opendir $gHandle, $_path)) {
-		$self->{'err_string'} = "groups(): Unable to read directory '$_path': $!";
-		return undef;
-	}
 
-	foreach my $group (readdir($gHandle)) {
-		next if (($group eq '.') || ($group eq '..'));
+	if (opendir $gHandle, $_path) {
+		my @groups;
 
-		if (-d make_path(SCST_TARGETS_DIR(), $driver,
-				 $target, SCST_GROUPS, $group)) {
-			push @groups, $group;
+		foreach my $group (readdir($gHandle)) {
+			next if ($group eq '.' || $group eq '..');
+
+			if (-d make_path(SCST_TARGETS_DIR(), $driver,
+					 $target, SCST_GROUPS, $group)) {
+				push @groups, $group;
+			}
 		}
+		close $gHandle;
+		return (\@groups, undef);
 	}
 
-	close $gHandle;
-
-	return \@groups;
+	my $errorString;
+	if ($self->driverExists($driver) != TRUE) {
+		$errorString = "groups(): Driver '$driver' is not available";
+	} elsif ($self->targetExists($driver, $target) != TRUE) {
+		$errorString = "groups(): Target '$target' is not available";
+	} else {
+		$errorString = "groups(): Unable to read directory '$_path': $!";
+	}
+	return (undef, $errorString);
 }
 
 sub initiators {
@@ -609,27 +645,24 @@ sub initiators {
 	my $group = shift;
 	my @initiators;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "initiators(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "initiators(): Target '$target' is not available";
-		return undef;
-	}
-
-	if ($self->groupExists($driver, $target, $group) != TRUE) {
-		$self->{'err_string'} = "initiators(): Group '$group' does not exist";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver) || !defined($target) ||
+			 !defined($group));
 
 	my $iHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
 			      $group, SCST_INITIATORS);
 	if (!(opendir $iHandle, $_path)) {
-		$self->{'err_string'} = "initiators(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "initiators(): Driver '$driver' is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "initiators(): Target '$target' is not available";
+		} elsif ($self->groupExists($driver, $target, $group) != TRUE) {
+			$errorString = "initiators(): Group '$group' does not exist";
+		} else {
+			$errorString = "initiators(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $initiator (readdir($iHandle)) {
@@ -641,7 +674,7 @@ sub initiators {
 
 	close $iHandle;
 
-	return \@initiators;
+	return (\@initiators, undef);
 }
 
 sub luns {
@@ -649,26 +682,12 @@ sub luns {
 	my $driver = shift;
 	my $target = shift;
 	my $group = shift;
-	my %luns;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "luns(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "luns(): Target '$target' is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver) || !defined($target));
 
 	my $_path;
 
 	if (defined($group)) {
-		if ($self->groupExists($driver, $target, $group) != TRUE) {
-			$self->{'err_string'} = "initiators(): Group '$group' does not exist";
-			return undef;
-		}
-
 		$_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 				   SCST_GROUPS, $group, SCST_LUNS);
 	} else {
@@ -679,10 +698,21 @@ sub luns {
 	my $lHandle = new IO::Handle;
 
 	if (!(opendir $lHandle, $_path)) {
-		$self->{'err_string'} = "luns(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if (defined($group) && $self->groupExists($driver, $target, $group) != TRUE) {
+			$errorString = "initiators(): Group '$group' does not exist";
+		} elsif ($self->driverExists($driver) != TRUE) {
+			$errorString = "luns(): Driver '$driver' is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "luns(): Target '$target' is not available";
+		} else {
+			$errorString = "luns(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
+	my %luns;
+
 	foreach my $lun (readdir($lHandle)) {
 		next if (($lun eq '.') || ($lun eq '..'));
 
@@ -692,8 +722,7 @@ sub luns {
 			my $_lHandle = new IO::Handle;
 
 			if (!(opendir $_lHandle, $lPath)) {
-				$self->{'err_string'} = "luns(): Unable to read directory '$lPath': $!";
-				return undef;
+				return (undef, "luns(): Unable to read directory '$lPath': $!");
 			}
 
 			foreach my $attribute (readdir($_lHandle)) {
@@ -705,12 +734,67 @@ sub luns {
 					$luns{$lun} = $linked;
 				}
 			}
+
+			close $_lHandle;
 		}
 	}
 
 	close $lHandle;
 
-	return \%luns;
+	return (\%luns, undef);
+}
+
+sub aluaAttributes {
+	my $self = shift;
+	my %attributes;
+
+	my $pHandle = new IO::Handle;
+	my $_path = SCST_DEV_GROUP_DIR();
+	if (!(opendir $pHandle, $_path)) {
+		return (undef, "deviceGroupsAttributes(): Unable to read directory '$_path': $!");
+	}
+
+	foreach my $attribute (readdir($pHandle)) {
+		next if ($attribute eq '.' || $attribute eq '..' ||
+			 $attribute eq SCST_MGMT_IO || $attribute eq 'uevent');
+		my $pPath = make_path(SCST_DEV_GROUP_DIR(), $attribute);
+		my $mode = (stat($pPath))[2];
+
+		if (!($mode & S_IRUSR)) {
+			$attributes{$attribute}->{'static'} = FALSE;
+			$attributes{$attribute}->{'value'} = undef;
+		} else {
+			my $is_static = !($mode & S_IWUSR);
+			my $io = new IO::File $pPath, O_RDONLY;
+
+			if (!$io) {
+				return (undef, "deviceGroupsAttributes(): Unable to read device attribute '$attribute': $!");
+			}
+
+			my $value = <$io>;
+			chomp $value;
+
+			my $second_line = <$io>;
+			if (new_sysfs_interface() && !$is_static
+			    || ($second_line =~ /\[key\]/)) {
+				my $key = 0;
+				if ($attribute =~ /^([^\d]+)(\d+)$/) {
+					$attribute = $1;
+					$key = $2;
+				}
+				$attributes{$attribute}->{'keys'}->{$key}->{'value'} = $value;
+			} else {
+				$attributes{$attribute}->{'value'} = $value;
+			}
+			close $io;
+
+			$attributes{$attribute}->{'static'} = $is_static;
+		}
+	}
+
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub deviceGroups {
@@ -720,8 +804,7 @@ sub deviceGroups {
 	my $dHandle = new IO::Handle;
 	my $_path = SCST_DEV_GROUP_DIR();
 	if (!(opendir $dHandle, $_path)) {
-		$self->{'err_string'} = "deviceGroups(): Unable to read directory '$_path': $!";
-		return undef;
+		return (undef, "deviceGroups(): Unable to read directory '$_path': $!");
 	}
 
 	foreach my $group (readdir($dHandle)) {
@@ -734,7 +817,7 @@ sub deviceGroups {
 
 	close $dHandle;
 
-	return \@groups;
+	return (\@groups, undef);
 }
 
 sub deviceGroupDevices {
@@ -742,16 +825,18 @@ sub deviceGroupDevices {
 	my $group = shift;
 	my @devices;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "deviceGroupDevices(): Device group '$group' does not exist";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($group));
 
 	my $dHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_DEVICES);
 	if (!(opendir $dHandle, $_path)) {
-		$self->{'err_string'} = "deviceGroupDevices(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceGroupExists($group) != TRUE) {
+			$errorString = "deviceGroupDevices(): Device group '$group' does not exist";
+		} else {
+			$errorString = "deviceGroupDevices(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $device (readdir($dHandle)) {
@@ -764,7 +849,7 @@ sub deviceGroupDevices {
 
 	close $dHandle;
 
-	return \@devices;
+	return (\@devices, undef);
 }
 
 sub targetGroups {
@@ -772,16 +857,18 @@ sub targetGroups {
 	my $group = shift;
 	my @tgroups;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroups(): Device group '$group' does not exist";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($group));
 
 	my $dHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS);
 	if (!(opendir $dHandle, $_path)) {
-		$self->{'err_string'} = "targetGroups(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceGroupExists($group) != TRUE) {
+			$errorString = "targetGroups(): Device group '$group' does not exist";
+		} else {
+			$errorString = "targetGroups(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $tgroup (readdir($dHandle)) {
@@ -794,7 +881,7 @@ sub targetGroups {
 
 	close $dHandle;
 
-	return \@tgroups;
+	return (\@tgroups, undef);
 }
 
 sub targetGroupTargets {
@@ -803,21 +890,20 @@ sub targetGroupTargets {
 	my $tgroup = shift;
 	my @targets;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargets(): Device group '$group' does not exist";
-		return undef;
-	}
-
-	if ($self->targetGroupExists($group, $tgroup) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargets(): Target group '$tgroup' does not exist";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($group) || !defined($tgroup));
 
 	my $dHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS, $tgroup);
 	if (!(opendir $dHandle, $_path)) {
-		$self->{'err_string'} = "targetGroupTargets(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceGroupExists($group) != TRUE) {
+			$errorString = "targetGroupTargets(): Device group '$group' does not exist";
+		} elsif ($self->targetGroupExists($group, $tgroup) != TRUE) {
+			$errorString = "targetGroupTargets(): Target group '$tgroup' does not exist";
+		} else {
+			$errorString = "targetGroupTargets(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $tgt (readdir($dHandle)) {
@@ -830,14 +916,18 @@ sub targetGroupTargets {
 
 	close $dHandle;
 
-	return \@targets;
+	@targets = sort(@targets);
+
+	return (\@targets, undef);
 }
 
 sub driverExists {
 	my $self = shift;
 	my $driver = shift;
 
-	my $drivers = $self->drivers();
+	return FALSE if (!defined($driver));
+
+	my ($drivers, $errorString) = $self->drivers();
 
 	return SCST_C_FATAL_ERROR if (!defined($drivers));
 
@@ -854,11 +944,7 @@ sub driverDynamicAttributes {
 	my %attributes;
 	my $available;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "driverDynamicAttributes(): Driver '$driver' ".
-		  "is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver));
 
 	if (new_sysfs_interface()) {
 		my $io = new IO::File make_path(SCST_TARGETS_DIR(), $driver,
@@ -868,15 +954,22 @@ sub driverDynamicAttributes {
 				chomp($attribute);
 				$attributes{$attribute} = '';
 			}
+			close $io;
 		}
 	} else {
 		my $io = new IO::File make_path(SCST_TARGETS_DIR(), $driver,
 						SCST_MGMT_IO), O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "driverDynamicAttributes(): Unable to open mgmt ".
-			    "interface for driver '$driver': $!";
-			return undef;
+			my $errorString;
+			if ($self->driverExists($driver) != TRUE) {
+				$errorString = "driverDynamicAttributes(): Driver '$driver' ".
+				    "is not available";
+			} else {
+				$errorString = "driverDynamicAttributes(): Unable to open mgmt ".
+				    "interface for driver '$driver': $!";
+			}
+			return (undef, $errorString);
 		}
 
 		while (my $in = <$io>) {
@@ -885,6 +978,7 @@ sub driverDynamicAttributes {
 				$available =~ s/\.$//;
 			}
 		}
+		close $io;
 
 		if ($available) {
 			foreach my $attribute (split(/\,/, $available)) {
@@ -895,7 +989,7 @@ sub driverDynamicAttributes {
 		}
 	}
 
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub checkDriverDynamicAttributes {
@@ -903,16 +997,18 @@ sub checkDriverDynamicAttributes {
 	my $driver = shift;
 	my $check = shift;
 
+	my ($available, $errorString) = $self->driverDynamicAttributes($driver);
+
+	if (!defined($available)) {
+		my $rc = $self->driverExists($driver);
+		return SCST_C_DRV_NO_DRIVER if (!$rc);
+		return $rc if (!$rc > 1);
+
+		return SCST_C_FATAL_ERROR;
+	}
+
 	return FALSE if (!defined($check));
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if (!$rc > 1);
-
-	my $available = $self->driverDynamicAttributes($driver);
-
-	return SCST_C_FATAL_ERROR if (!defined($available));
-
 	if (ref($check) eq 'HASH') {
 		foreach my $attribute (keys %{$check}) {
 			if (!defined($$available{$attribute})) {
@@ -934,15 +1030,8 @@ sub addDriverDynamicAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
-
-	$rc = $self->checkDriverDynamicAttributes($driver, $attribute);
-	return SCST_C_DRV_BAD_ATTRIBUTES if ($rc == 1);
-	return $rc if ($rc > 1);
+	return SCST_C_DRV_ADDATTR_FAIL
+	    if (!defined($driver) || !defined($attribute) || !defined($value));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -954,30 +1043,17 @@ sub addDriverDynamicAttribute {
 	$cmd .= "add_attribute $attribute $value";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DRV_ADDATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DRV_ADDATTR_FAIL;
-
-}
-
-sub removeDriverDynamicAttribute {
-	my $self = shift;
-	my $driver = shift;
-	my $attribute = shift;
-	my $value = shift;
-
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -988,6 +1064,18 @@ sub removeDriverDynamicAttribute {
 	return SCST_C_DRV_BAD_ATTRIBUTES if ($rc == 1);
 	return $rc if ($rc > 1);
 
+	return SCST_C_DRV_ADDATTR_FAIL;
+}
+
+sub removeDriverDynamicAttribute {
+	my $self = shift;
+	my $driver = shift;
+	my $attribute = shift;
+	my $value = shift;
+
+	return SCST_C_DRV_REMATTR_FAIL
+	    if (!defined($driver) || !defined($attribute) || !defined($value));
+
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
 		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
@@ -998,20 +1086,27 @@ sub removeDriverDynamicAttribute {
 	$cmd .= "del_attribute $attribute $value";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DRV_REMATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
+
+	$rc = $self->checkDriverDynamicAttributes($driver, $attribute);
+	return SCST_C_DRV_BAD_ATTRIBUTES if ($rc == 1);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_DRV_REMATTR_FAIL;
 }
 
@@ -1020,37 +1115,21 @@ sub targetExists {
 	my $driver = shift;
 	my $target = shift;
 
-	return FALSE if (!defined($target));
-
-	my $rc = $self->driverExists($driver);
-
-	return FALSE if (!$rc);
-	return $rc if ($rc > 1);
-
-	my $targets = $self->targets($driver);
-
-	return SCST_C_FATAL_ERROR if (!defined($targets));
-
-	foreach my $_target (@{$targets}) {
-		return TRUE if ($target eq $_target);
-	}
-
-	return FALSE;
+	return defined($driver) && defined($target) &&
+	    $target ne '.' && $target ne '..' && $target ne 'module' &&
+	    (-d make_path(SCST_TARGETS_DIR(), $driver, $target)) ? TRUE : FALSE;
 }
 
 sub driverIsVirtualCapable {
 	my $self = shift;
 	my $driver = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
 	if (new_sysfs_interface()) {
 		my $path = make_path(SCST_TARGETS_DIR(), $driver, SCST_ADD_TGT);
 		my $io = new IO::File $path, O_RDONLY;
 		if ($io) {
 			my $line = <$io>;
+			close $io;
 			chomp($line);
 			return $line eq '1';
 		}
@@ -1066,8 +1145,10 @@ sub targetType {
 	my $driver = shift;
 	my $target = shift;
 
+	return (undef, "Too few arguments") if (!defined($driver) || !defined($target));
+
 	if ($self->driverIsVirtualCapable($driver)) {
-		my $attribs = $self->targetAttributes($driver, $target);
+		my ($attribs, $errorString) = $self->targetAttributes($driver, $target);
 
 		if (defined($$attribs{'hw_target'}) &&
 		    ($$attribs{'hw_target'}->{'value'} == TRUE)) {
@@ -1086,21 +1167,7 @@ sub addVirtualTarget {
 	my $target = shift;
 	my $attributes = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_EXISTS if ($rc);
-	return $rc if ($rc > 1);
-
-	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
-
-	$rc = $self->checkTargetCreateAttributes($driver, $attributes);
-	return SCST_C_TGT_BAD_ATTRIBUTES if ($rc == TRUE);
-	return $rc if ($rc > 1);
-
-	my $o_string;
+	my $o_string = "";
 	foreach my $attribute (keys %{$attributes}) {
 		if (ref($$attributes{$attribute}) eq 'ARRAY') {
 			foreach my $value (@{$$attributes{$attribute}}) {
@@ -1124,20 +1191,31 @@ sub addVirtualTarget {
 	$cmd .= "add_target $target $o_string";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGT_ADD_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_EXISTS if ($rc);
+	return $rc if ($rc > 1);
+
+	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
+
+	$rc = $self->checkTargetCreateAttributes($driver, $attributes);
+	return SCST_C_TGT_BAD_ATTRIBUTES if ($rc == TRUE);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_TGT_ADD_FAIL;
 }
 
@@ -1147,11 +1225,7 @@ sub targetDynamicAttributes {
 	my %attributes;
 	my $available;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "targetDynamicAttributes(): Driver '$driver' ".
-		  "is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver));
 
 	if (new_sysfs_interface()) {
 		my $io = new IO::File make_path(SCST_TARGETS_DIR(), $driver,
@@ -1161,15 +1235,22 @@ sub targetDynamicAttributes {
 				chomp($attribute);
 				$attributes{$attribute} = '';
 			}
+			close $io;
 		}
 	} else {
 		my $io = new IO::File make_path(SCST_TARGETS_DIR(), $driver,
 						SCST_MGMT_IO), O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "targetDynamicAttributes(): Unable to open mgmt ".
-			    "interface for driver '$driver': $!";
-			return undef;
+			my $errorString;
+			if ($self->driverExists($driver) != TRUE) {
+				$errorString = "targetDynamicAttributes(): Driver '$driver' ".
+				    "is not available";
+			} else {
+				$errorString = "targetDynamicAttributes(): Unable to open mgmt ".
+				    "interface for driver '$driver': $!";
+			}
+			return (undef, $errorString);
 		}
 
 		while (my $in = <$io>) {
@@ -1178,6 +1259,7 @@ sub targetDynamicAttributes {
 				$available =~ s/\.$//;
 			}
 		}
+		close $io;
 
 		if ($available) {
 			foreach my $attribute (split(/\,/, $available)) {
@@ -1188,7 +1270,7 @@ sub targetDynamicAttributes {
 		}
 	}
 
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub checkTargetDynamicAttributes {
@@ -1196,16 +1278,18 @@ sub checkTargetDynamicAttributes {
 	my $driver = shift;
 	my $check = shift;
 
+	my ($available, $errorString) = $self->targetDynamicAttributes($driver);
+
+	if (!defined($available)) {
+		my $rc = $self->driverExists($driver);
+		return SCST_C_DRV_NO_DRIVER if (!$rc);
+		return $rc if (!$rc > 1);
+
+		return SCST_C_FATAL_ERROR;
+	}
+
 	return FALSE if (!defined($check));
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if (!$rc > 1);
-
-	my $available = $self->targetDynamicAttributes($driver);
-
-	return SCST_C_FATAL_ERROR if (!defined($available));
-
 	if (ref($check) eq 'HASH') {
 		foreach my $attribute (keys %{$check}) {
 			if (!defined($$available{$attribute})) {
@@ -1228,19 +1312,9 @@ sub addTargetDynamicAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
-
-	$rc = $self->checkTargetDynamicAttributes($driver, $attribute);
-	return SCST_C_TGT_BAD_ATTRIBUTES if ($rc == 1);
-	return $rc if ($rc > 1);
+	return SCST_C_TGT_ADDATTR_FAIL
+	    if (!defined($driver) || !defined($target) ||
+		!defined($attribute) || !defined($value));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1252,30 +1326,17 @@ sub addTargetDynamicAttribute {
 	$cmd .= "add_target_attribute $target $attribute $value";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGT_ADDATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_TGT_ADDATTR_FAIL;
-}
-
-sub removeTargetDynamicAttribute {
-	my $self = shift;
-	my $driver = shift;
-	my $target = shift;
-	my $attribute = shift;
-	my $value = shift;
-
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -1290,6 +1351,20 @@ sub removeTargetDynamicAttribute {
 	return SCST_C_TGT_BAD_ATTRIBUTES if ($rc == 1);
 	return $rc if ($rc > 1);
 
+	return SCST_C_TGT_ADDATTR_FAIL;
+}
+
+sub removeTargetDynamicAttribute {
+	my $self = shift;
+	my $driver = shift;
+	my $target = shift;
+	my $attribute = shift;
+	my $value = shift;
+
+	return SCST_C_TGT_REMATTR_FAIL
+	    if (!defined($driver) || !defined($target) ||
+		!defined($attribute) || !defined($value));
+
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
 		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
@@ -1300,28 +1375,17 @@ sub removeTargetDynamicAttribute {
 	$cmd .= "del_target_attribute $target $attribute $value";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGT_REMATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_TGT_REMATTR_FAIL;
-}
-
-sub removeVirtualTarget {
-	my $self = shift;
-	my $driver = shift;
-	my $target = shift;
-
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -1332,9 +1396,23 @@ sub removeVirtualTarget {
 
 	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
 
+	$rc = $self->checkTargetDynamicAttributes($driver, $attribute);
+	return SCST_C_TGT_BAD_ATTRIBUTES if ($rc == 1);
+	return $rc if ($rc > 1);
+
+	return SCST_C_TGT_REMATTR_FAIL;
+}
+
+sub removeVirtualTarget {
+	my $self = shift;
+	my $driver = shift;
+	my $target = shift;
+
+	# May fail if the target does not have an 'enabled' attribute as is the
+	# case for e.g. the 'scst_local' driver.
 	$self->enableTarget($driver, $target, FALSE);
 
-	my $sessions = $self->sessions($driver, $target);
+	my ($sessions, $errorString) = $self->sessions($driver, $target);
 
 	my %can_close;
 	foreach my $session (keys %{$sessions}) {
@@ -1349,7 +1427,7 @@ sub removeVirtualTarget {
 		my $has_sessions = 1;
 		my $now = time();
 		while ($has_sessions && (($now + $TIMEOUT) > time())) {
-			$sessions = $self->sessions($driver, $target);
+			($sessions, $errorString) = $self->sessions($driver, $target);
 
 			foreach my $session (keys %can_close) {
 				if (!defined($$sessions{$session})) {
@@ -1374,21 +1452,27 @@ sub removeVirtualTarget {
 	$cmd .= "del_target $target";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGT_REM_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	return SCST_C_DRV_NOTVIRT if (!$self->driverIsVirtualCapable($driver));
 
-	return SCST_C_TGT_BUSY if ($bytes == -1);
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_TGT_REM_FAIL;
 }
 
@@ -1398,16 +1482,17 @@ sub groupExists {
 	my $target = shift;
 	my $group = shift;
 
-	return FALSE if (!defined($group));
+	return FALSE if (!defined($driver) || !defined($target) || !defined($group));
 
-	my $rc = $self->targetExists($driver, $target);
+	my ($groups, $errorString) = $self->groups($driver, $target);
 
-	return FALSE if (!$rc);
-	return $rc if ($rc > 1);
+	if (!defined($groups)) {
+		my $rc = $self->targetExists($driver, $target);
+		return FALSE if (!$rc);
+		return $rc if ($rc > 1);
 
-	my $groups = $self->groups($driver, $target);
-
-	return SCST_C_FATAL_ERROR if (!defined($groups));
+		return SCST_C_FATAL_ERROR;
+	}
 
 	foreach my $_group (@{$groups}) {
 		return TRUE if ($group eq $_group);
@@ -1423,16 +1508,18 @@ sub initiatorExists {
 	my $group = shift;
 	my $initiator = shift;
 
-	return FALSE if (!defined($initiator));
+	return FALSE if (!defined($driver) || !defined($target) ||
+			 !defined($group) || !defined($initiator));
 
-	my $rc = $self->groupExists($driver, $target, $group);
+	my ($initiators, $errorString) = $self->initiators($driver, $target, $group);
 
-	return FALSE if (!$rc);
-	return $rc if ($rc > 1);
+	if (!defined($initiators)) {
+		my $rc = $self->groupExists($driver, $target, $group);
+		return FALSE if (!$rc);
+		return $rc if ($rc > 1);
 
-	my $initiators = $self->initiators($driver, $target, $group);
-
-	return SCST_C_FATAL_ERROR if (!defined($initiators));
+		return SCST_C_FATAL_ERROR;
+	}
 
 	foreach my $_initiator (@{$initiators}) {
 		return TRUE if ($initiator eq $_initiator);
@@ -1448,27 +1535,28 @@ sub lunExists {
 	my $lun = shift;
 	my $group = shift;
 
-	return FALSE if (!defined($lun));
+	return FALSE if (!defined($driver) || !defined($target) ||
+			 !defined($lun));
 
+	my ($luns, $errorString) = $self->luns($driver, $target, $group);
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_EXISTS if (!$rc);
-	return $rc if ($rc > 1);
-
-	if (defined($group)) {
-		my $rc = $self->groupExists($driver, $target, $group);
-		return SCST_C_GRP_NO_GROUP if (!$rc);
+	if (!defined($luns)) {
+		my $rc = $self->driverExists($driver);
+		return SCST_C_DRV_NO_DRIVER if (!$rc);
 		return $rc if ($rc > 1);
+
+		$rc = $self->targetExists($driver, $target);
+		return SCST_C_TGT_NO_TARGET if (!$rc);
+		return $rc if ($rc > 1);
+
+		if (defined($group)) {
+			my $rc = $self->groupExists($driver, $target, $group);
+			return SCST_C_GRP_NO_GROUP if (!$rc);
+			return $rc if ($rc > 1);
+		}
+		return SCST_C_FATAL_ERROR;
 	}
 
-	my $luns = $self->luns($driver, $target, $group);
-
-	return SCST_C_FATAL_ERROR if (!defined($luns));
-
 	foreach my $_lun (keys %{$luns}) {
 		return TRUE if ($lun == $_lun);
 	}
@@ -1482,17 +1570,8 @@ sub addGroup {
 	my $target = shift;
 	my $group = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->groupExists($driver, $target, $group);
-	return SCST_C_GRP_EXISTS if ($rc == TRUE);
-	return $rc if ($rc > 1);
+	return SCST_C_GRP_ADD_FAIL if (!defined($driver) || !defined($target) ||
+				       !defined($group));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1506,20 +1585,29 @@ sub addGroup {
 	$cmd .= "create $group";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_ADD_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->groupExists($driver, $target, $group);
+	return SCST_C_GRP_EXISTS if ($rc == TRUE);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_GRP_ADD_FAIL;
 }
 
@@ -1529,6 +1617,32 @@ sub removeGroup {
 	my $target = shift;
 	my $group = shift;
 
+	return SCST_C_GRP_REM_FAIL if (!defined($driver) || !defined($target) ||
+				       !defined($group));
+
+	my ($path, $cmd);
+	if (new_sysfs_interface()) {
+		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
+		$cmd = "in " . make_path(IN_SCST_TARGETS, $driver, $target,
+					 SCST_GROUPS) . " ";
+	} else {
+		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
+				  SCST_GROUPS, SCST_MGMT_IO);
+	}
+	$cmd .= "del $group";
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -1541,32 +1655,6 @@ sub removeGroup {
 	return SCST_C_GRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
 
-	my ($path, $cmd);
-	if (new_sysfs_interface()) {
-		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
-		$cmd = "in " . make_path(IN_SCST_TARGETS, $driver, $target,
-					 SCST_GROUPS) . " ";
-	} else {
-		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
-				  SCST_GROUPS, SCST_MGMT_IO);
-	}
-	$cmd .= "del $group";
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_REM_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_GRP_REM_FAIL;
 }
 
@@ -1574,9 +1662,7 @@ sub addDeviceGroup {
 	my $self = shift;
 	my $group = shift;
 
-	my $rc = $self->deviceGroupExists($group);
-	return SCST_C_DEV_GRP_EXISTS if ($rc == TRUE);
-	return $rc if ($rc > 1);
+	return SCST_C_DEV_GRP_ADD_FAIL if (!defined($group));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1588,30 +1674,27 @@ sub addDeviceGroup {
 	$cmd .= "create $group";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DEV_GRP_ADD_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DEV_GRP_ADD_FAIL;
+	my $rc = $self->deviceGroupExists($group);
+	return $rc == TRUE ? SCST_C_DEV_GRP_EXISTS : $rc > 1 ? $rc :
+	    SCST_C_DEV_GRP_ADD_FAIL;
 }
 
 sub removeDeviceGroup {
 	my $self = shift;
 	my $group = shift;
 
-	my $rc = $self->deviceGroupExists($group);
-	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
+	return SCST_C_DEV_GRP_REM_FAIL if (!defined($group));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1623,20 +1706,21 @@ sub removeDeviceGroup {
 	$cmd .= "del $group";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DEV_GRP_REM_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->deviceGroupExists($group);
+	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_DEV_GRP_REM_FAIL;
 }
 
@@ -1645,6 +1729,30 @@ sub addDeviceGroupDevice {
 	my $group = shift;
 	my $device = shift;
 
+	return SCST_C_DGRP_ADD_DEV_FAIL if (!defined($group) || !defined($device));
+
+	my ($path, $cmd);
+	if (new_sysfs_interface()) {
+		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
+		$cmd = "in " . make_path(IN_SCST_DEV_GROUPS, $group,
+					 SCST_DG_DEVICES) . " ";
+	} else {
+		$path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_DEVICES, SCST_MGMT_IO);
+	}
+	$cmd .= "add $device";
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->deviceGroupExists($group);
 	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
@@ -1658,41 +1766,16 @@ sub addDeviceGroupDevice {
 	return $rc if ($rc > 1);
 
 	# Check all device groups for this device
-	my $dgroups = $self->deviceGroups();
+	my ($dgroups, $errorString) = $self->deviceGroups();
 
 	foreach my $dgroup (@{$dgroups}) {
-		my $devs = $self->deviceGroupDevices($dgroup);
+		my ($devs, $errorString) = $self->deviceGroupDevices($dgroup);
 
 		foreach my $dev (@{$devs}) {
 			return SCST_C_DGRP_DEVICE_OTHER if ($dev eq $device);
 		}
 	}
 
-	my ($path, $cmd);
-	if (new_sysfs_interface()) {
-		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
-		$cmd = "in " . make_path(IN_SCST_DEV_GROUPS, $group,
-					 SCST_DG_DEVICES) . " ";
-	} else {
-		$path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_DEVICES, SCST_MGMT_IO);
-	}
-	$cmd .= "add $device";
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DGRP_ADD_DEV_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_DGRP_ADD_DEV_FAIL;
 }
 
@@ -1701,13 +1784,8 @@ sub addTargetGroup {
 	my $group = shift;
 	my $tgroup = shift;
 
-	my $rc = $self->deviceGroupExists($group);
-	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetGroupExists($group, $tgroup);
-	return SCST_C_DGRP_GROUP_EXISTS if ($rc == TRUE);
-	return $rc if ($rc > 1);
+	return SCST_C_DGRP_ADD_GRP_FAIL if (!defined($group) ||
+					    !defined($tgroup));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1720,21 +1798,24 @@ sub addTargetGroup {
 	$cmd .= "add $tgroup";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DGRP_ADD_GRP_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->deviceGroupExists($group);
+	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DGRP_ADD_GRP_FAIL;
+	$rc = $self->targetGroupExists($group, $tgroup);
+	return SCST_C_DGRP_GROUP_EXISTS if ($rc == TRUE);
+	return $rc > 1 ? $rc : SCST_C_DGRP_ADD_GRP_FAIL;
 }
 
 sub addTargetGroupTarget {
@@ -1743,17 +1824,9 @@ sub addTargetGroupTarget {
 	my $tgroup = shift;
 	my $tgt = shift;
 
-	my $rc = $self->deviceGroupExists($group);
-	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetGroupExists($group, $tgroup);
-	return SCST_C_DGRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetGroupTargetExists($group, $tgroup, $tgt);
-	return SCST_C_TGRP_TGT_EXISTS if ($rc == TRUE);
-	return $rc if ($rc > 1);
+	return SCST_C_TGRP_ADD_TGT_FAIL if (!defined($group) ||
+					    !defined($tgroup) ||
+					    !defined($tgt));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1767,21 +1840,27 @@ sub addTargetGroupTarget {
 	$cmd .= "add $tgt";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGRP_ADD_TGT_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->deviceGroupExists($group);
+	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_TGRP_ADD_TGT_FAIL;
+	$rc = $self->targetGroupExists($group, $tgroup);
+	return SCST_C_DGRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetGroupTargetExists($group, $tgroup, $tgt);
+	return $rc == TRUE ? SCST_C_TGRP_TGT_EXISTS : $rc > 1 ? $rc : SCST_C_TGRP_ADD_TGT_FAIL;
 }
 
 sub removeDeviceGroupDevice {
@@ -1789,6 +1868,30 @@ sub removeDeviceGroupDevice {
 	my $group = shift;
 	my $device = shift;
 
+	return SCST_C_DGRP_REM_DEV_FAIL if (!defined($group) || !defined($device));
+
+	my ($path, $cmd);
+	if (new_sysfs_interface()) {
+		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
+		$cmd = "in " . make_path(IN_SCST_DEV_GROUPS, $group,
+					 SCST_DG_DEVICES) . " ";
+	} else {
+		$path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_DEVICES, SCST_MGMT_IO);
+	}
+	$cmd .= "del $device";
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->deviceGroupExists($group);
 	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
@@ -1801,31 +1904,6 @@ sub removeDeviceGroupDevice {
 	return SCST_C_DGRP_NO_DEVICE if (!$rc);
 	return $rc if ($rc > 1);
 
-	my ($path, $cmd);
-	if (new_sysfs_interface()) {
-		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
-		$cmd = "in " . make_path(IN_SCST_DEV_GROUPS, $group,
-					 SCST_DG_DEVICES) . " ";
-	} else {
-		$path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_DEVICES, SCST_MGMT_IO);
-	}
-	$cmd .= "del $device";
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DGRP_REM_DEV_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_DGRP_REM_DEV_FAIL;
 }
 
@@ -1834,13 +1912,7 @@ sub removeTargetGroup {
 	my $group = shift;
 	my $tgroup = shift;
 
-	my $rc = $self->deviceGroupExists($group);
-	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetGroupExists($group, $tgroup);
-	return SCST_C_DGRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
+	return SCST_C_DGRP_REM_GRP_FAIL if (!defined($group) || !defined($tgroup));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1853,29 +1925,17 @@ sub removeTargetGroup {
 	$cmd .= "del $tgroup";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DGRP_REM_GRP_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DGRP_REM_GRP_FAIL;
-}
-
-sub removeTargetGroupTarget {
-	my $self = shift;
-	my $group = shift;
-	my $tgroup = shift;
-	my $tgt = shift;
-
 	my $rc = $self->deviceGroupExists($group);
 	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
@@ -1884,9 +1944,16 @@ sub removeTargetGroupTarget {
 	return SCST_C_DGRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
 
-	$rc = $self->targetGroupTargetExists($group, $tgroup, $tgt);
-	return SCST_C_TGRP_NO_TGT if (!$rc);
-	return $rc if ($rc > 1);
+	return SCST_C_DGRP_REM_GRP_FAIL;
+}
+
+sub removeTargetGroupTarget {
+	my $self = shift;
+	my $group = shift;
+	my $tgroup = shift;
+	my $tgt = shift;
+
+	return SCST_C_TGRP_REM_TGT_FAIL if (!defined($group) || !defined($tgroup) || !defined($tgt));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -1900,20 +1967,29 @@ sub removeTargetGroupTarget {
 	$cmd .= "del $tgt";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGRP_REM_TGT_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->deviceGroupExists($group);
+	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetGroupExists($group, $tgroup);
+	return SCST_C_DGRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetGroupTargetExists($group, $tgroup, $tgt);
+	return SCST_C_TGRP_NO_TGT if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_TGRP_REM_TGT_FAIL;
 }
 
@@ -1924,6 +2000,39 @@ sub addInitiator {
 	my $group = shift;
 	my $initiator = shift;
 
+	return SCST_C_GRP_ADD_INI_FAIL
+	    if (!defined($driver) || !defined($target) ||
+		!defined($group) || !defined($initiator));
+
+	my ($path, $cmd);
+	if (new_sysfs_interface()) {
+		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
+		$cmd = "in " . make_path(IN_SCST_TARGETS, $driver, $target,
+					 SCST_GROUPS, $group, SCST_INITIATORS) .
+					     " ";
+	} else {
+		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
+				  SCST_GROUPS, $group, SCST_INITIATORS,
+				  SCST_MGMT_IO);
+	}
+	$cmd .= "add $initiator";
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
+	return SCST_C_GRP_REM_INI_FAIL if (!defined($driver) ||
+					   !defined($target) ||
+					   !defined($initiator));
+
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -1940,6 +2049,18 @@ sub addInitiator {
 	return SCST_C_GRP_INI_EXISTS if ($rc == TRUE);
 	return $rc if ($rc > 1);
 
+	return SCST_C_GRP_ADD_INI_FAIL;
+}
+
+sub removeInitiator {
+	my $self = shift;
+	my $driver = shift;
+	my $target = shift;
+	my $group = shift;
+	my $initiator = shift;
+
+	return SCST_C_GRP_REM_INI_FAIL if (!defined($driver) || !defined($target) || !defined($group) || !defined($initiator));
+
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
 		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
@@ -1951,33 +2072,20 @@ sub addInitiator {
 				  SCST_GROUPS, $group, SCST_INITIATORS,
 				  SCST_MGMT_IO);
 	}
-	$cmd .= "add $initiator";
+	$cmd .= "del $initiator";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_ADD_INI_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_GRP_ADD_INI_FAIL;
-}
-
-sub removeInitiator {
-	my $self = shift;
-	my $driver = shift;
-	my $target = shift;
-	my $group = shift;
-	my $initiator = shift;
-
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -1994,34 +2102,6 @@ sub removeInitiator {
 	return SCST_C_GRP_NO_INI if (!$rc);
 	return $rc if ($rc > 1);
 
-	my ($path, $cmd);
-	if (new_sysfs_interface()) {
-		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
-		$cmd = "in " . make_path(IN_SCST_TARGETS, $driver, $target,
-					 SCST_GROUPS, $group, SCST_INITIATORS) .
-					     " ";
-	} else {
-		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
-				  SCST_GROUPS, $group, SCST_INITIATORS,
-				  SCST_MGMT_IO);
-	}
-	$cmd .= "del $initiator";
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_REM_INI_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_GRP_REM_INI_FAIL;
 }
 
@@ -2033,6 +2113,31 @@ sub moveInitiator {
 	my $to = shift;
 	my $initiator = shift;
 
+	my ($path, $cmd);
+	if (new_sysfs_interface()) {
+		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
+		$cmd = "in " . make_path(IN_SCST_TARGETS, $driver, $target,
+					 SCST_GROUPS, $from, SCST_INITIATORS) .
+					     " ";
+	} else {
+		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
+				  SCST_GROUPS, $from, SCST_INITIATORS,
+				  SCST_MGMT_IO);
+	}
+	$cmd .= "move $initiator $to";
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -2057,34 +2162,6 @@ sub moveInitiator {
 	return SCST_C_GRP_INI_EXISTS if ($rc == TRUE);
 	return $rc if ($rc > 1);
 
-	my ($path, $cmd);
-	if (new_sysfs_interface()) {
-		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
-		$cmd = "in " . make_path(IN_SCST_TARGETS, $driver, $target,
-					 SCST_GROUPS, $from, SCST_INITIATORS) .
-					     " ";
-	} else {
-		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
-				  SCST_GROUPS, $from, SCST_INITIATORS,
-				  SCST_MGMT_IO);
-	}
-	$cmd .= "move $initiator $to";
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_MOV_INI_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_GRP_MOV_INI_FAIL;
 }
 
@@ -2094,18 +2171,6 @@ sub clearInitiators {
 	my $target = shift;
 	my $group = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->groupExists($driver, $target, $group);
-	return SCST_C_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
 		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
@@ -2120,20 +2185,29 @@ sub clearInitiators {
 	$cmd .= "clear";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_CLR_INI_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->groupExists($driver, $target, $group);
+	return SCST_C_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_GRP_CLR_INI_FAIL;
 }
 
@@ -2146,45 +2220,14 @@ sub addLun {
 	my $attributes = shift;
 	my $group = shift;
 
-	my $err;
-	my $err2;
+	my $err = defined($group) ? SCST_C_GRP_ADD_LUN_FAIL :
+	    SCST_C_TGT_ADD_LUN_FAIL;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
+	return $err if (!defined($driver) || !defined($target) ||
+			!defined($device) || !defined($lun) ||
+			!defined($attributes));
 
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->deviceOpen($device);
-	return SCST_C_DEV_NO_DEVICE if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->checkLunCreateAttributes($driver, $target, $attributes, $group);
-	return SCST_C_LUN_BAD_ATTRIBUTES if ($rc == TRUE);
-	return $rc if ($rc > 1);
-
-	if (defined($group)) {
-		$rc = $self->groupExists($driver, $target, $group);
-		return SCST_C_GRP_NO_GROUP if (!$rc);
-		return $rc if ($rc > 1);
-
-		$err  = SCST_C_GRP_ADD_LUN_FAIL;
-		$err2 = SCST_C_GRP_LUN_EXISTS;
-
-	} else {
-		$err  = SCST_C_TGT_ADD_LUN_FAIL;
-		$err2 = SCST_C_TGT_LUN_EXISTS;
-	}
-
-	return $err if (!defined($lun));
-
-	$rc = $self->lunExists($driver, $target, $lun, $group);
-	return $err2 if ($rc == TRUE);
-	return $rc if ($rc > 1);
-
-	my $o_string;
+	my $o_string = "";
 	foreach my $attribute (keys %{$attributes}) {
 		my $value = $$attributes{$attribute};
 		$o_string .= "$attribute=$value; ";
@@ -2217,20 +2260,44 @@ sub addLun {
 	$cmd .= "add $device $lun $o_string";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return $err if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	if (defined($group)) {
+		my $rc = $self->groupExists($driver, $target, $group);
+		return SCST_C_GRP_NO_GROUP if (!$rc);
+		return $rc if ($rc > 1);
+	}
+
+	my $rc = $self->lunExists($driver, $target, $lun, $group);
+	return (defined($group) ? SCST_C_GRP_LUN_EXISTS :
+		SCST_C_TGT_LUN_EXISTS) if ($rc == TRUE);
+	return $rc if ($rc > 1);
+
+	$rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->deviceOpen($device);
+	return SCST_C_DEV_NO_DEVICE if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->checkLunCreateAttributes($driver, $target, $attributes, $group);
+	return SCST_C_LUN_BAD_ATTRIBUTES if ($rc == TRUE);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return $err;
 }
 
@@ -2241,34 +2308,11 @@ sub removeLun {
 	my $lun = shift;
 	my $group = shift;
 
-	my $err;
-	my $err2;
+	my $err = defined($group) ? SCST_C_GRP_REM_LUN_FAIL :
+	    SCST_C_TGT_ADD_LUN_FAIL;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	if (defined($group)) {
-		$rc = $self->groupExists($driver, $target, $group);
-		return SCST_C_GRP_NO_GROUP if (!$rc);
-		return $rc if ($rc > 1);
-
-		$err  = SCST_C_GRP_REM_LUN_FAIL;
-		$err2 = SCST_C_GRP_NO_LUN;
-	} else {
-		$err  = SCST_C_TGT_ADD_LUN_FAIL;
-		$err2 = SCST_C_TGT_NO_LUN;
-	}
-
-	return $err if (!defined($lun));
-
-	$rc = $self->lunExists($driver, $target, $lun, $group);
-	return $err2 if (!$rc);
-	return $rc if ($rc > 1);
+	return $err if (!defined($driver) || !defined($target) ||
+			!defined($lun));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -2294,20 +2338,36 @@ sub removeLun {
 	$cmd .= "del $lun";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return $err if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	if (defined($group)) {
+		$rc = $self->groupExists($driver, $target, $group);
+		return SCST_C_GRP_NO_GROUP if (!$rc);
+		return $rc if ($rc > 1);
+	}
+
+	$rc = $self->lunExists($driver, $target, $lun, $group);
+	return (defined($group) ? SCST_C_GRP_NO_LUN : SCST_C_TGT_NO_LUN)
+	    if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
 	return $err;
 }
 
@@ -2354,11 +2414,11 @@ sub replaceLun {
 	return SCST_C_LUN_BAD_ATTRIBUTES if ($rc == TRUE);
 	return $rc if ($rc > 1);
 
-	my $luns = $self->luns($driver, $target, $group);
+	my ($luns, $errorString) = $self->luns($driver, $target, $group);
 
 	return SCST_C_LUN_DEV_EXISTS if ($$luns{$lun} eq $device);
 
-	my $o_string;
+	my $o_string = "";
 	foreach my $attribute (keys %{$attributes}) {
 		my $value = $$attributes{$attribute};
 		$o_string .= "$attribute=$value; ";
@@ -2390,20 +2450,17 @@ sub replaceLun {
 	$cmd .= "replace $device $lun $o_string";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_LUN_RPL_DEV_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_LUN_RPL_DEV_FAIL;
 }
 
@@ -2413,25 +2470,10 @@ sub clearLuns {
 	my $target = shift;
 	my $group = shift;
 
-	my $err;
+	my $err = defined($group) ? SCST_C_GRP_CLR_LUN_FAIL :
+	    SCST_C_TGT_CLR_LUN_FAIL;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	if (defined($group)) {
-		$rc = $self->groupExists($driver, $target, $group);
-		return SCST_C_GRP_NO_GROUP if (!$rc);
-		return $rc if ($rc > 1);
-
-		$err = SCST_C_GRP_CLR_LUN_FAIL;
-	} else {
-		$err = SCST_C_TGT_CLR_LUN_FAIL
-	}
+	return $err if (!defined($driver) || !defined($target));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -2457,21 +2499,32 @@ sub clearLuns {
 	$cmd .= "clear";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return $err if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_GRP_CLR_LUN_FAIL;
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	if (defined($group)) {
+		$rc = $self->groupExists($driver, $target, $group);
+		return SCST_C_GRP_NO_GROUP if (!$rc);
+		return $rc if ($rc > 1);
+	}
+
+	return $err;
 }
 
 sub deviceHandler {
@@ -2493,8 +2546,7 @@ sub devices {
 	my $_path = new_sysfs_interface() || !defined($handler) ?
 	    SCST_DEVICES_DIR() : make_path(SCST_HANDLERS_DIR(), $handler);
 	if (!(opendir $dHandle, $_path)) {
-		$self->{'err_string'} = "devices(): Unable to read directory '$_path': $!";
-		return undef;
+		return (undef, "devices(): Unable to read directory '$_path': $!");
 	}
 
 	foreach my $device (readdir($dHandle)) {
@@ -2510,7 +2562,7 @@ sub devices {
 
 	close $dHandle;
 
-	return \@devices;
+	return (\@devices, undef);
 }
 
 sub deviceOpen {
@@ -2519,7 +2571,7 @@ sub deviceOpen {
 
 	return FALSE if (!defined($device));
 
-	my $devices = $self->devices();
+	my ($devices, $errorString) = $self->devices();
 
 	return SCST_C_FATAL_ERROR if (!defined($devices));
 
@@ -2535,19 +2587,19 @@ sub deviceAttributes {
 	my $device = shift;
 	my %attributes;
 
-	if ($self->deviceOpen($device) != TRUE) {
-		$self->{'err_string'} = "deviceAttributes(): Device '$device' is not open";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEVICES_DIR(), $device);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "deviceAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceOpen($device) != TRUE) {
+			$errorString = "deviceAttributes(): Device '$device' is not open";
+		} else {
+			$errorString = "deviceAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
-	my $dca = $self->deviceCreateAttributes($self->deviceHandler($device));
+	my ($dca, $errorString) = $self->deviceCreateAttributes($self->deviceHandler($device));
 
 	foreach my $attribute (readdir($pHandle)) {
 		next if ($attribute eq '.' || $attribute eq '..' ||
@@ -2579,6 +2631,7 @@ sub deviceAttributes {
 
 				$attributes{$attribute}->{'static'} = TRUE;
 			}
+			close $eHandle;
 		} elsif ($attribute eq 'handler') {
 			my $linked = readlink $pPath;
 
@@ -2610,24 +2663,23 @@ sub deviceAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "deviceAttributes(): Unable to read ".
-					  "device attribute '$attribute': $!";
-					return undef;
+					return (undef, "deviceAttributes(): Unable to read ".
+					  "device attribute '$attribute': $!");
 				}
 
 				my ($value, $is_key) = split("\n", _sysread($io) , 2);
-
+				close $io;
 				chomp $value;
 
 				$is_key = new_sysfs_interface() &&
 				    (!$is_static || defined($$dca{$attribute}))
-				    || ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    || $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -2651,7 +2703,9 @@ sub deviceAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub driverAttributes {
@@ -2659,16 +2713,16 @@ sub driverAttributes {
 	my $driver = shift;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "driverAttributes(): Driver '$driver' is not available";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "driverAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "driverAttributes(): Driver '$driver' is not available";
+		} else {
+			$errorString = "driverAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -2694,9 +2748,8 @@ sub driverAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "driverAttributes(): Unable to read ".
-					  "driver attribute '$attribute': $!";
-					return undef;
+					return (undef, "driverAttributes(): Unable to read ".
+					  "driver attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
@@ -2704,13 +2757,13 @@ sub driverAttributes {
 
 				my $is_key = <$io>;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -2743,13 +2796,16 @@ sub driverAttributes {
 						$attributes{$attribute}->{'value'} = $value;
 					}
 				}
+				close $io;
 
 				$attributes{$attribute}->{'static'} = $is_static;
 			}
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub setDriverAttribute {
@@ -2758,35 +2814,28 @@ sub setDriverAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
 	return TRUE if (!defined($attribute) || !defined($value));
 
-	my $attributes = $self->driverAttributes($driver);
-
-	return SCST_C_DRV_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_DRV_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
 	my $path = make_path(SCST_TARGETS_DIR(), $driver, $attribute);
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DRV_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DRV_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_DRV_BAD_ATTRIBUTES,
+			     SCST_C_DRV_ATTRIBUTE_STATIC);
 }
 
 sub targetAttributes {
@@ -2795,21 +2844,20 @@ sub targetAttributes {
 	my $target = shift;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "targetAttributes(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "targetAttributes(): Target '$target' is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver) || !defined($target));
 
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver, $target);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "targetAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "targetAttributes(): Driver '$driver' is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "targetAttributes(): Target '$target' is not available";
+		} else {
+			$errorString = "targetAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -2829,8 +2877,7 @@ sub targetAttributes {
 			my $_session_path = make_path($_path, $attribute);
 			my $pSessHandle = new IO::Handle;
 			if (!(opendir $pSessHandle, $_session_path)) {
-				$self->{'err_string'} = "targetAttributes(): Unable to read directory '$_session_path': $!";
-				return undef;
+				return (undef, "targetAttributes(): Unable to read directory '$_session_path': $!");
 			}
 			my $key = 0;
 			foreach my $e (readdir($pSessHandle)) {
@@ -2857,23 +2904,23 @@ sub targetAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "targetAttributes(): Unable to read ".
-					  "target attribute '$attribute': $!";
-					return undef;
+					return (undef, "targetAttributes(): Unable to read ".
+					  "target attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
-				chomp $value;
+				chomp $value if (defined($value));
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -2890,7 +2937,9 @@ sub targetAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub setTargetAttribute {
@@ -2900,21 +2949,8 @@ sub setTargetAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
 	return TRUE if (!defined($attribute) || !defined($value));
 
-	my $attributes = $self->targetAttributes($driver, $target);
-
-	return SCST_C_TGT_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_TGT_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
 	my ($path, $cmd);
 	if (new_sysfs_interface() &&
 	    ($attribute eq 'enabled' || $attribute eq 'cpu_mask')) {
@@ -2930,21 +2966,27 @@ sub setTargetAttribute {
 	}
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGT_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $cmd > $path\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $cmd > $path\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_TGT_SETATTR_FAIL;
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	return setAttrFailed($path, SCST_C_TGT_BAD_ATTRIBUTES,
+			     SCST_C_TGT_ATTRIBUTE_STATIC);
 }
 
 sub groupAttributes {
@@ -2954,27 +2996,21 @@ sub groupAttributes {
 	my $group = shift;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "groupAttributes(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "groupAttributes(): Target '$target' is not available";
-		return undef;
-	}
-
-	if ($self->groupExists($driver, $target, $group) != TRUE) {
-		$self->{'err_string'} = "groupAttributes(): Group '$group' does not exist";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
 			      $group);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "groupAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "groupAttributes(): Driver '$driver' is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "groupAttributes(): Target '$target' is not available";
+		} elsif ($self->groupExists($driver, $target, $group) != TRUE) {
+			$errorString = "groupAttributes(): Group '$group' does not exist";
+		} else {
+			$errorString = "groupAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -3002,23 +3038,23 @@ sub groupAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "groupAttributes(): Unable to read ".
-					  "group attribute '$attribute': $!";
-					return undef;
+					return (undef, "groupAttributes(): Unable to read ".
+					  "group attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
 				chomp $value;
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -3035,7 +3071,9 @@ sub groupAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub setGroupAttribute {
@@ -3046,25 +3084,8 @@ sub setGroupAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->groupExists($driver, $target, $group);
-	return SCST_C_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
 	return TRUE if (!defined($attribute) || !defined($value));
 
-	my $attributes = $self->groupAttributes($driver, $target, $group);
-
-	return SCST_C_GRP_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_GRP_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
 	my ($path, $cmd);
 	if (new_sysfs_interface() && $attribute eq 'cpu_mask') {
 		$path = make_path(SCST_ROOT_DIR(), SCST_MGMT_IO);
@@ -3078,21 +3099,31 @@ sub setGroupAttribute {
 	$cmd .= $value;
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_GRP_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $cmd > $path\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $cmd > $path\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_GRP_SETATTR_FAIL;
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
+
+	$rc = $self->groupExists($driver, $target, $group);
+	return SCST_C_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
+
+	return setAttrFailed($path, SCST_C_GRP_BAD_ATTRIBUTES,
+			     SCST_C_GRP_ATTRIBUTE_STATIC);
 }
 
 sub lunAttributes {
@@ -3101,45 +3132,36 @@ sub lunAttributes {
 	my $target = shift;
 	my $lun = shift;
 	my $group = shift;
+	my $errorString;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "lunAttributes(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "lunAttributes(): Target '$target' is not available";
-		return undef;
-	}
-
 	my ($_path, $luncrattr);
 
 	if (defined($group)) {
-		if ($self->groupExists($driver, $target, $group) != TRUE) {
-			$self->{'err_string'} = "lunAttributes(): Group '$group' does not exist";
-			return undef;
-		}
-
 		$_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 				   SCST_GROUPS, $group, SCST_LUNS, $lun);
-		$luncrattr = $self->lunCreateAttributes($driver, $target,
-							$group);
+		($luncrattr, $errorString) =
+		    $self->lunCreateAttributes($driver, $target, $group);
 	} else {
 		$_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 				   SCST_LUNS, $lun);
-		$luncrattr = $self->lunCreateAttributes($driver, $target);
-	}
-
-	if ($self->lunExists($driver, $target, $lun, $group) != TRUE) {
-		$self->{'err_string'} = "lunAttributes(): LUN '$lun' does not exist";
-		return undef;
+		($luncrattr, $errorString) = $self->lunCreateAttributes($driver, $target);
 	}
 
 	my $pHandle = new IO::Handle;
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "lunAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "lunAttributes(): Driver '$driver' is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "lunAttributes(): Target '$target' is not available";
+		} elsif (defined($group) && $self->groupExists($driver, $target, $group) != TRUE) {
+			$errorString = "lunAttributes(): Group '$group' does not exist";
+		} elsif ($self->lunExists($driver, $target, $lun, $group) != TRUE) {
+			$errorString = "lunAttributes(): LUN '$lun' does not exist";
+		} else {
+			$errorString = "lunAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -3171,25 +3193,25 @@ sub lunAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "lunAttributes(): Unable to read ".
-					  "lun attribute '$attribute': $!";
-					return undef;
+					return (undef, "lunAttributes(): Unable to read ".
+					  "lun attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
 				chomp $value;
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() &&
 				    (!$is_static ||
 				     defined($$luncrattr{$attribute})) ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -3206,7 +3228,9 @@ sub lunAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub setLunAttribute {
@@ -3218,21 +3242,13 @@ sub setLunAttribute {
 	my $value = shift;
 	my $group = shift;
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
+	return SCST_C_LUN_SETATTR_FAIL
+	    if (!defined($driver) || !defined($target) || !defined($lun) ||
+		!defined($attribute) || !defined($value));
 
 	my $path;
 
 	if (defined($group)) {
-		$rc = $self->groupExists($driver, $target, $group);
-		return SCST_C_GRP_NO_GROUP if (!$rc);
-		return $rc if ($rc > 1);
-
 		$path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 				  SCST_GROUPS, $group, SCST_LUNS, $lun,
 				  $attribute);
@@ -3241,32 +3257,42 @@ sub setLunAttribute {
 				  SCST_LUNS, $lun, $attribute);
 	}
 
-	$rc = $self->lunExists($driver, $target, $lun, $group);
-	return SCST_C_GRP_NO_LUN if (!$rc);
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
+	my $rc = $self->driverExists($driver);
+	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
 
-	return TRUE if (!defined($attribute) || !defined($value));
+	$rc = $self->targetExists($driver, $target);
+	return SCST_C_TGT_NO_TARGET if (!$rc);
+	return $rc if ($rc > 1);
 
-	my $attributes = $self->lunAttributes($driver, $target, $group, $lun);
+	if (defined($group)) {
+		$rc = $self->groupExists($driver, $target, $group);
+		return SCST_C_GRP_NO_GROUP if (!$rc);
+		return $rc if ($rc > 1);
+	}
+
+	$rc = $self->lunExists($driver, $target, $lun, $group);
+	return (defined($group) ? SCST_C_GRP_NO_LUN : SCST_C_TGT_NO_LUN)
+	    if (!$rc);
+	return $rc if ($rc > 1);
+
+	my ($attributes, $errorString) = $self->lunAttributes($driver, $target, $lun, $group);
 
 	return SCST_C_LUN_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
 	return SCST_C_LUN_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
 
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_LUN_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_LUN_SETATTR_FAIL;
 }
 
@@ -3278,32 +3304,23 @@ sub initiatorAttributes {
 	my $initiator = shift;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "initiatorAttributes(): Driver '$driver' is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "initiatorAttributes(): Target '$target' is not available";
-		return undef;
-	}
-
-	if ($self->groupExists($driver, $target, $group) != TRUE) {
-		$self->{'err_string'} = "initiatorAttributes(): Group '$group' does not exist";
-		return undef;
-	}
-
-	if ($self->initiatorExists($driver, $target, $group, $initiator) != TRUE) {
-		$self->{'err_string'} = "initiatorAttributes(): Initiator '$initiator' does not exist";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
 			      $group, SCST_INITIATORS, $initiator);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "initiatorAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "initiatorAttributes(): Driver '$driver' is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "initiatorAttributes(): Target '$target' is not available";
+		} elsif ($self->groupExists($driver, $target, $group) != TRUE) {
+			$errorString = "initiatorAttributes(): Group '$group' does not exist";
+		} elsif ($self->initiatorExists($driver, $target, $group, $initiator) != TRUE) {
+			$errorString = "initiatorAttributes(): Initiator '$initiator' does not exist";
+		} else {
+			$errorString = "initiatorAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -3330,23 +3347,23 @@ sub initiatorAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "initiatorAttributes(): Unable to read ".
-					  "initiator attribute '$attribute': $!";
-					return undef;
+					return (undef, "initiatorAttributes(): Unable to read ".
+					  "initiator attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
 				chomp $value;
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -3363,7 +3380,9 @@ sub initiatorAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub setInitiatorAttribute {
@@ -3375,6 +3394,23 @@ sub setInitiatorAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
+	return TRUE if (!defined($attribute) || !defined($value));
+
+	my $path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
+			     $group, SCST_LUNS, $initiator, $attribute);
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->driverExists($driver);
 	return SCST_C_DRV_NO_DRIVER if (!$rc);
 	return $rc if ($rc > 1);
@@ -3391,31 +3427,6 @@ sub setInitiatorAttribute {
 	return SCST_C_GRP_NO_INI if (!$rc);
 	return $rc if ($rc > 1);
 
-	return TRUE if (!defined($attribute) || !defined($value));
-
-	my $attributes = $self->initiatorAttributes($driver, $target, $group, $initiator);
-
-	return SCST_C_INI_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_INI_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
-	my $path = make_path(SCST_TARGETS_DIR(), $driver, $target, SCST_GROUPS,
-			     $group, SCST_LUNS, $initiator, $attribute);
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_INI_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_INI_SETATTR_FAIL;
 }
 
@@ -3424,16 +3435,16 @@ sub deviceGroupAttributes {
 	my $group = shift;
 	my %attributes;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroupAttributes(): Device group '$group' does not exist";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEV_GROUP_DIR(), $group);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "deviceGroupAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceGroupExists($group) != TRUE) {
+			$errorString = "deviceGroupAttributes(): Device group '$group' does not exist";
+		} else {
+			$errorString = "deviceGroupAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -3458,23 +3469,23 @@ sub deviceGroupAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "deviceGroupAttributes(): Unable to read ".
-					  "device group attribute '$attribute': $!";
-					return undef;
+					return (undef, "deviceGroupAttributes(): Unable to read ".
+					  "device group attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
 				chomp $value;
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -3491,7 +3502,9 @@ sub deviceGroupAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub targetGroupAttributes {
@@ -3500,21 +3513,18 @@ sub targetGroupAttributes {
 	my $tgroup = shift;
 	my %attributes;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroupAttributes(): Device group '$group' does not exist";
-		return undef;
-	}
-
-	if ($self->targetGroupExists($group, $tgroup) != TRUE) {
-		$self->{'err_string'} = "targetGroupAttributes(): Target Group '$tgroup' does not exist";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS, $tgroup);
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "targetGroupAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceGroupExists($group) != TRUE) {
+			$errorString = "targetGroupAttributes(): Device group '$group' does not exist";
+		} elsif ($self->targetGroupExists($group, $tgroup) != TRUE) {
+			$errorString = "targetGroupAttributes(): Target Group '$tgroup' does not exist";
+		} else {
+			$errorString = "targetGroupAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -3539,23 +3549,23 @@ sub targetGroupAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "targetGroupAttributes(): Unable to read ".
-					  "target group attribute '$attribute': $!";
-					return undef;
+					return (undef, "targetGroupAttributes(): Unable to read ".
+					  "target group attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
 				chomp $value;
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -3572,7 +3582,9 @@ sub targetGroupAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
 }
 
 sub targetGroupTargetAttributes {
@@ -3580,28 +3592,27 @@ sub targetGroupTargetAttributes {
 	my $group = shift;
 	my $tgroup = shift;
 	my $tgt = shift;
+	my $local_tgt = shift;
 	my %attributes;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargetAttributes(): Device group '$group' does not exist";
-		return undef;
-	}
-
-	if ($self->targetGroupExists($group, $tgroup) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargetAttributes(): Target Group '$tgroup' does not exist";
-		return undef;
-	}
-
-	if ($self->targetGroupTargetExists($group, $tgroup, $tgt) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargetAttributes(): Target '$tgt' does not exist";
-		return undef;
-	}
-
 	my $pHandle = new IO::Handle;
 	my $_path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS, $tgroup, $tgt);
+	if (-l $_path && !$local_tgt) {
+		return (\%attributes, undef);
+	}
+
 	if (!(opendir $pHandle, $_path)) {
-		$self->{'err_string'} = "targetGroupTargetAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->deviceGroupExists($group) != TRUE) {
+			$errorString = "targetGroupTargetAttributes(): Device group '$group' does not exist";
+		} elsif ($self->targetGroupExists($group, $tgroup) != TRUE) {
+			$errorString = "targetGroupTargetAttributes(): Target Group '$tgroup' does not exist";
+		} elsif ($self->targetGroupTargetExists($group, $tgroup, $tgt) != TRUE) {
+			$errorString = "targetGroupTargetAttributes(): Target '$tgt' does not exist";
+		} else {
+			$errorString = "targetGroupTargetAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($pHandle)) {
@@ -3627,23 +3638,23 @@ sub targetGroupTargetAttributes {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "targetGroupTargetAttributes(): Unable to read ".
-					  "target group target attribute '$attribute': $!";
-					return undef;
+					return (undef, "targetGroupTargetAttributes(): Unable to read ".
+					  "target group target attribute '$attribute': $!");
 				}
 
 				my $value = <$io>;
 				chomp $value;
 
 				my $is_key = <$io>;
+				close $io;
 				$is_key = new_sysfs_interface() && !$is_static ||
-				    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+				    $is_key && $is_key =~ /\[key\]/;
 
 				my $key = 0;
 				if ($is_key) {
-					if ($attribute =~ /.*(\d+)$/) {
-						$key = $1;
-						$attribute =~ s/\d+$//;
+					if ($attribute =~ /^([^\d]+)(\d+)$/) {
+						$attribute = $1;
+						$key = $2;
 					}
 				}
 
@@ -3660,7 +3671,33 @@ sub targetGroupTargetAttributes {
 		}
 	}
 
-	return \%attributes;
+	close $pHandle;
+
+	return (\%attributes, undef);
+}
+
+sub setAluaAttribute {
+	my $self = shift;
+	my $attribute = shift;
+	my $value = shift;
+
+	return TRUE if (!defined($attribute) || !defined($value));
+
+	my $path = make_path(SCST_DEV_GROUP_DIR(), $attribute);
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $value > $path\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
+	return setAttrFailed($path, SCST_C_ALUA_BAD_ATTRIBUTES,
+			     SCST_C_ALUA_ATTRIBUTE_STATIC);
 }
 
 sub setDeviceGroupAttribute {
@@ -3669,35 +3706,28 @@ sub setDeviceGroupAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->deviceGroupExists($group);
-	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
-
 	return TRUE if (!defined($attribute) || !defined($value));
 
-	my $attributes = $self->deviceGroupAttributes($group);
-
-	return SCST_C_DGRP_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_DGRP_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
 	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, $attribute);
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DGRP_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->deviceGroupExists($group);
+	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DGRP_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_DGRP_BAD_ATTRIBUTES,
+				     SCST_C_DGRP_ATTRIBUTE_STATIC);
 }
 
 sub setTargetGroupAttribute {
@@ -3707,6 +3737,23 @@ sub setTargetGroupAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
+	return TRUE if (!defined($group) || !defined($tgroup) ||
+			!defined($attribute) || !defined($value));
+
+	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS, $tgroup, $attribute);
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->deviceGroupExists($group);
 	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
@@ -3715,31 +3762,8 @@ sub setTargetGroupAttribute {
 	return SCST_C_DGRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
 
-	return TRUE if (!defined($attribute) || !defined($value));
-
-	my $attributes = $self->targetGroupAttributes($group, $tgroup);
-
-	return SCST_C_TGRP_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_TGRP_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
-	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS, $tgroup, $attribute);
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGRP_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_TGRP_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_TGRP_BAD_ATTRIBUTES,
+			     SCST_C_TGRP_ATTRIBUTE_STATIC);
 }
 
 sub setTargetGroupTargetAttribute {
@@ -3750,6 +3774,25 @@ sub setTargetGroupTargetAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
+	return TRUE if (!defined($group) || !defined($tgroup) ||
+			!defined($tgt) || !defined($attribute) ||
+			!defined($value));
+
+	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS,
+			     $tgroup, $tgt, $attribute);
+
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->deviceGroupExists($group);
 	return SCST_C_DEV_GRP_NO_GROUP if (!$rc);
 	return $rc if ($rc > 1);
@@ -3762,32 +3805,8 @@ sub setTargetGroupTargetAttribute {
 	return SCST_C_TGRP_NO_TGT if (!$rc);
 	return $rc if ($rc > 1);
 
-	return TRUE if (!defined($attribute) || !defined($value));
-
-	my $attributes = $self->targetGroupTargetAttributes($group, $tgroup, $tgt);
-
-	return SCST_C_TGRP_TGT_BAD_ATTR if (!defined($$attributes{$attribute}));
-	return SCST_C_TGRP_TGT_ATTR_STATIC if ($$attributes{$attribute}->{'static'});
-
-	my $path = make_path(SCST_DEV_GROUP_DIR(), $group, SCST_DG_TGROUPS,
-			     $tgroup, $tgt, $attribute);
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_TGRP_TGT_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_TGRP_TGT_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_TGRP_TGT_BAD_ATTR,
+			     SCST_C_TGRP_TGT_ATTR_STATIC);
 }
 
 sub handlers {
@@ -3797,8 +3816,7 @@ sub handlers {
 	my $hHandle = new IO::Handle;
 	my $_path = SCST_HANDLERS_DIR();
 	if (!(opendir $hHandle, $_path)) {
-		$self->{'err_string'} = "handlers(): Unable to read directory '$_path': $!";
-		return undef;
+		return (undef, "handlers(): Unable to read directory '$_path': $!");
 	}
 
 	foreach my $handler (readdir($hHandle)) {
@@ -3811,7 +3829,7 @@ sub handlers {
 
 	close $hHandle;
 
-	return \@handlers;
+	return (\@handlers, undef);
 }
 
 sub handlerExists {
@@ -3820,7 +3838,7 @@ sub handlerExists {
 
 	return FALSE if (!defined($handler));
 
-	my $handlers = $self->handlers();
+	my ($handlers, $errorString) = $self->handlers();
 
 	return SCST_C_FATAL_ERROR if (!defined($handlers));
 
@@ -3837,35 +3855,27 @@ sub setHandlerAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
+	return TRUE if (!defined($attribute) || !defined($value));
+
+	my $path = make_path(SCST_HANDLERS_DIR(), $handler, $attribute);
+	my $io = new IO::File $path, O_WRONLY;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $path -> $attribute = $value\n";
+		} else {
+			$bytes = _syswrite($io, $value, length($value));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
+	}
+
 	my $rc = $self->handlerExists($handler);
 	return SCST_C_HND_NO_HANDLER if (!$rc);
 	return $rc if ($rc > 1);
 
-	return TRUE if (!defined($attribute) || !defined($value));
-
-	my $attributes = $self->handlerAttributes($handler);
-
-	return SCST_C_HND_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_HND_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
-	my $path = make_path(SCST_HANDLERS_DIR(), $handler, $attribute);
-
-	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_HND_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $path -> $attribute = $value\n";
-	} else {
-		$bytes = _syswrite($io, $value, length($value));
-	}
-
-	close $io;
-
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_HND_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_HND_BAD_ATTRIBUTES,
+			     SCST_C_HND_ATTRIBUTE_STATIC);
 }
 
 sub handlerAttributes {
@@ -3873,18 +3883,19 @@ sub handlerAttributes {
 	my $handler = shift;
 	my %attributes;
 
-	if ($self->handlerExists($handler) != TRUE) {
-		$self->{'err_string'} = "handlerAttributes(): Handler '$handler' is not available";
-		return undef;
-	}
-
-	$attributes{'devices'}->{'value'} = devices($self, $handler);
+	my ($a, $errorString) = devices($self, $handler);
+	$attributes{'devices'}->{'value'} = $a;
 
 	my $hHandle = new IO::Handle;
 	my $_path = make_path(SCST_HANDLERS_DIR(), $handler);
 	if (!(opendir $hHandle, $_path)) {
-		$self->{'err_string'} = "handlerAttributes(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->handlerExists($handler) != TRUE) {
+			$errorString = "handlerAttributes(): Handler '$handler' is not available";
+		} else {
+			$errorString = "handlerAttributes(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $attribute (readdir($hHandle)) {
@@ -3906,23 +3917,22 @@ sub handlerAttributes {
 		my $io = new IO::File $path, O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "handlerAttributes(): Unable to read handler attribute ".
-			  "'$attribute': $!";
-			return undef;
+			return (undef, "handlerAttributes(): Unable to read handler attribute ".
+			  "'$attribute': $!");
 		}
 
 		my $value = <$io>;
-		chomp $value;
+		chomp $value if (defined($value));
 
 		my $is_key = <$io>;
 		$is_key = new_sysfs_interface() && !$is_static ||
-		    ($is_key =~ /\[key\]/) ? TRUE : FALSE;
+		    $is_key && $is_key =~ /\[key\]/;
 
 		my $key = 0;
 		if ($is_key) {
-			if ($attribute =~ /.*(\d+)$/) {
-				$key = $1;
-				$attribute =~ s/\d+$//;
+			if ($attribute =~ /^([^\d]+)(\d+)$/) {
+				$attribute = $1;
+				$key = $2;
 			}
 		}
 
@@ -3969,16 +3979,18 @@ sub handlerAttributes {
 		close $io;
 	}
 
+	close $hHandle;
+
 	$attributes{'devices'}->{'static'} = TRUE;
 
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub deviceExists {
 	my $self = shift;
 	my $device = shift;
 
-	my $handlers = $self->handlers();
+	my ($handlers, $errorString) = $self->handlers();
 
 	return SCST_C_FATAL_ERROR if (!defined($handlers));
 
@@ -3994,14 +4006,15 @@ sub handlerDeviceExists {
 	my $handler = shift;
 	my $device = shift;
 
-	my $rc = $self->handlerExists($handler);
+	my ($devices, $errorString) = $self->devicesByHandler($handler);
 
-	return FALSE if (!$rc);
-	return $rc if ($rc > 1);
+	if (!defined($devices)) {
+		my $rc = $self->handlerExists($handler);
+		return FALSE if (!$rc);
+		return $rc if ($rc > 1);
 
-	my $devices = $self->devicesByHandler($handler);
-
-	return SCST_C_FATAL_ERROR if (!defined($devices));
+		return SCST_C_FATAL_ERROR;
+	}
 
 	foreach my $_device (@{$devices}) {
 		return TRUE if ($_device eq $device);
@@ -4014,15 +4027,19 @@ sub devicesByHandler {
 	my $self = shift;
 	my $handler = shift;
 
-	if ($self->handlerExists($handler) != TRUE) {
-		$self->{'err_string'} = "devicesByHandler(): Handler '$handler' is not available";
-		return undef;
+	my ($attributes, $errorString) = $self->handlerAttributes($handler);
+
+	if (!defined($attributes)) {
+		my $errorString;
+		if ($self->handlerExists($handler) != TRUE) {
+			$errorString = "devicesByHandler(): Handler '$handler' is not available";
+		} else {
+			$errorString = "devicesByHandler() failed";
+		}
+		return (undef, $errorString);
 	}
 
-	my $attributes = $self->handlerAttributes($handler);
-
-	return undef if (!defined($attributes));
-	return \@{$$attributes{'devices'}->{'value'}};
+	return (\@{$$attributes{'devices'}->{'value'}}, undef);
 }
 
 sub checkDeviceCreateAttributes {
@@ -4032,13 +4049,14 @@ sub checkDeviceCreateAttributes {
 
 	return FALSE if (!defined($check));
 
-	my $rc = $self->handlerExists($handler);
-	return SCST_C_HND_NO_HANDLER if (!$rc);
-	return $rc if (!$rc > 1);
+	my ($available, $errorString) = $self->deviceCreateAttributes($handler);
 
-	my $available = $self->deviceCreateAttributes($handler);
-
-	return SCST_C_FATAL_ERROR if (!defined($available));
+	if (!defined($available)) {
+		my $rc = $self->handlerExists($handler);
+		return SCST_C_HND_NO_HANDLER if (!$rc);
+		return $rc if (!$rc > 1);
+		return SCST_C_FATAL_ERROR;
+	}
 
 	if (ref($check) eq 'HASH') {
 		foreach my $attribute (keys %{$check}) {
@@ -4061,12 +4079,6 @@ sub deviceCreateAttributes {
 	my $available;
 	my %attributes;
 
-	if ($self->handlerExists($handler) != TRUE) {
-		$self->{'err_string'} = "deviceCreateAttributes(): Handler '$handler' ".
-		  "is not available";
-		return undef;
-	}
-
 	if (new_sysfs_interface()) {
 		my $io = new IO::File make_path(SCST_HANDLERS_DIR(), $handler,
 						SCST_ADD_DEV_PARAMS), O_RDONLY;
@@ -4075,14 +4087,21 @@ sub deviceCreateAttributes {
 			chomp($attribute);
 			$attributes{$attribute} = '';
 		}
+		close $io;
 	} else {
 		my $io = new IO::File make_path(SCST_HANDLERS_DIR(), $handler,
 						SCST_MGMT_IO), O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "deviceCreateAttributes(): Unable to open mgmt ".
-			    "interface for handler '$handler': $!";
-			return undef;
+			my $errorString;
+			if ($self->handlerExists($handler) != TRUE) {
+				$errorString = "deviceCreateAttributes(): Handler '$handler' ".
+				    "is not available";
+			} else {
+				$errorString = "deviceCreateAttributes(): Unable to open mgmt ".
+				    "interface for handler '$handler': $!";
+			}
+			return (undef, $errorString);
 		}
 
 		while (my $in = <$io>) {
@@ -4091,6 +4110,7 @@ sub deviceCreateAttributes {
 				$available =~ s/\.$//;
 			}
 		}
+		close $io;
 
 		if ($available) {
 			foreach my $attribute (split(/\,/, $available)) {
@@ -4101,7 +4121,7 @@ sub deviceCreateAttributes {
 		}
 	}
 
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub openDevice {
@@ -4110,19 +4130,11 @@ sub openDevice {
 	my $device = shift;
 	my $attributes = shift;
 
-	my $rc = $self->handlerExists($handler);
-	return SCST_C_HND_NO_HANDLER if (!$rc);
-	return $rc if ($rc > 1);
+	return SCST_C_DEV_OPEN_FAIL if (!defined($handler) ||
+					!defined($device) ||
+					!defined($attributes));
 
-	$rc = $self->checkDeviceCreateAttributes($handler, $attributes);
-	return SCST_C_DEV_BAD_ATTRIBUTES if ($rc == TRUE);
-	return $rc if ($rc > 1);
-
-	$rc = $self->handlerDeviceExists($handler, $device);
-	return SCST_C_DEV_EXISTS if ($rc == TRUE);
-	return $rc if ($rc > 1);
-
-	my $o_string;
+	my $o_string = "";
 	foreach my $attribute (keys %{$attributes}) {
 		my $value = $$attributes{$attribute};
 		$o_string .= "$attribute=$value; ";
@@ -4140,23 +4152,34 @@ sub openDevice {
 	$cmd .= "add_device $device $o_string";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	if (!$io) {
-		$self->{'err_string'} = "openDevice(): Unable to open mgmt interface for ".
-		  "handler '$handler': $!";
-		return SCST_C_FATAL_ERROR;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	my $bytes;
+	my $errno = $!;
 
-	if ($self->{'debug'}) {
-		print "DBG($$): $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
+	my $rc = $self->handlerExists($handler);
+	return SCST_C_HND_NO_HANDLER if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DEV_OPEN_FAIL;
+	$rc = $self->checkDeviceCreateAttributes($handler, $attributes);
+	return SCST_C_DEV_BAD_ATTRIBUTES if ($rc == TRUE);
+	return $rc if ($rc > 1);
+
+	$rc = $self->handlerDeviceExists($handler, $device);
+	return SCST_C_DEV_EXISTS if ($rc == TRUE);
+	return $rc if ($rc > 1);
+
+	return SCST_C_DEV_OPEN_FAIL if ($errno == EINVAL);
+
+	return SCST_C_FATAL_ERROR;
 }
 
 sub closeDevice {
@@ -4164,13 +4187,8 @@ sub closeDevice {
 	my $handler = shift;
 	my $device = shift;
 
-	my $rc = $self->handlerExists($handler);
-	return SCST_C_HND_NO_HANDLER if (!$rc);
-	return $rc if ($rc > 1);
-
-	$rc = $self->handlerDeviceExists($handler, $device);
-	return SCST_C_DEV_NO_DEVICE if ($rc != TRUE);
-	return $rc if ($rc > 1);
+	return SCST_C_DEV_CLOSE_FAIL if (!defined($handler) ||
+					 !defined($device));
 
 	my ($path, $cmd);
 	if (new_sysfs_interface()) {
@@ -4182,23 +4200,28 @@ sub closeDevice {
 	$cmd .= "del_device $device";
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	if (!$io) {
-		$self->{'err_string'} = "closeDevice(): Unable to open mgmt interface for handler ".
-		  "'$handler': $!";
-		return SCST_C_FATAL_ERROR;
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	my $bytes;
+	my $errno = $!;
 
-	if ($self->{'debug'}) {
-		print "DBG($$): $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
-	}
+	my $rc = $self->handlerExists($handler);
+	return SCST_C_HND_NO_HANDLER if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DEV_CLOSE_FAIL;
+	$rc = $self->handlerDeviceExists($handler, $device);
+	return SCST_C_DEV_NO_DEVICE if ($rc != TRUE);
+	return $rc if ($rc > 1);
+
+	return SCST_C_FATAL_ERROR;
 }
 
 sub setDeviceAttribute {
@@ -4207,17 +4230,6 @@ sub setDeviceAttribute {
 	my $attribute = shift;
 	my $value = shift;
 
-	my $rc = $self->deviceOpen($device);
-	return SCST_C_DEV_NO_DEVICE if (!$rc);
-	return $rc if ($rc > 1);
-
-	my $attributes = $self->deviceAttributes($device);
-
-	return SCST_C_FATAL_ERROR if (!defined($attributes));
-
-	return SCST_C_DEV_BAD_ATTRIBUTES if (!defined($$attributes{$attribute}));
-	return SCST_C_DEV_ATTRIBUTE_STATIC if ($$attributes{$attribute}->{'static'});
-
 	my ($path, $cmd);
 	if (new_sysfs_interface() &&
 	    ($attribute eq 'filename' ||
@@ -4231,21 +4243,23 @@ sub setDeviceAttribute {
 	$cmd .= $value;
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	return SCST_C_DEV_SETATTR_FAIL if (!$io);
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $cmd > $path\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $cmd > $path\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
 
-	close $io;
+	my $rc = $self->deviceOpen($device);
+	return SCST_C_DEV_NO_DEVICE if (!$rc);
+	return $rc if ($rc > 1);
 
-	return FALSE if ($self->{'debug'} || $bytes);
-	return SCST_C_DEV_SETATTR_FAIL;
+	return setAttrFailed($path, SCST_C_DEV_BAD_ATTRIBUTES,
+			     SCST_C_DEV_ATTRIBUTE_STATIC);
 }
 
 sub checkTargetCreateAttributes {
@@ -4255,13 +4269,14 @@ sub checkTargetCreateAttributes {
 
 	return FALSE if (!defined($check));
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
+	my ($available, $errorString) = $self->targetCreateAttributes($driver);
 
-	my $available = $self->targetCreateAttributes($driver);
-
-	return SCST_C_FATAL_ERROR if (!defined($available));
+	if (!defined($available)) {
+		my $rc = $self->driverExists($driver);
+		return SCST_C_DRV_NO_DRIVER if (!$rc);
+		return $rc if ($rc > 1);
+		return SCST_C_FATAL_ERROR;
+	}
 
 	if (ref($check) eq 'HASH') {
 		foreach my $attribute (keys %{$check}) {
@@ -4284,12 +4299,6 @@ sub targetCreateAttributes {
 	my $available;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "targetCreateAttributes(): Driver '$driver' ".
-		  "is not available";
-		return undef;
-	}
-
 	if (new_sysfs_interface()) {
 		my $io = new IO::File make_path(SCST_TARGETS_DIR(), $driver,
 						SCST_ADD_TGT_PARAMS), O_RDONLY;
@@ -4297,14 +4306,21 @@ sub targetCreateAttributes {
 			chomp($attribute);
 			$attributes{$attribute} = '';
 		}
+		close $io;
 	} else {
 		my $io = new IO::File make_path(SCST_TARGETS_DIR(), $driver,
 						SCST_MGMT_IO), O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "targetCreateAttributes(): Unable to open driver mgmt ".
-			    "interface for driver '$driver': $!";
-			return undef;
+			my $errorString;
+			if ($self->driverExists($driver) != TRUE) {
+				$errorString = "targetCreateAttributes(): Driver '$driver' ".
+				    "is not available";
+			} else {
+				$errorString = "targetCreateAttributes(): Unable to open driver mgmt ".
+				    "interface for driver '$driver': $!";
+			}
+			return (undef, $errorString);
 		}
 
 		while (my $in = <$io>) {
@@ -4313,6 +4329,7 @@ sub targetCreateAttributes {
 				$available =~ s/\.$//;
 			}
 		}
+		close $io;
 
 		if ($available) {
 			foreach my $attribute (split(/\,/, $available)) {
@@ -4323,7 +4340,7 @@ sub targetCreateAttributes {
 		}
 	}
 
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub enableTarget {
@@ -4356,7 +4373,7 @@ sub deviceGroupExists {
 	my $self = shift;
 	my $group = shift;
 
-	my $groups = $self->deviceGroups();
+	my ($groups, $errorString) = $self->deviceGroups();
 
 	return SCST_C_FATAL_ERROR if (!defined($groups));
 
@@ -4372,15 +4389,12 @@ sub deviceGroupDeviceExists {
 	my $group = shift;
 	my $device = shift;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "deviceGroupDeviceExists(): Device group '$group' does not exist";
-		return undef;
+	my ($devices, $errorString) = $self->deviceGroupDevices($group);
+
+	if (!defined($devices)) {
+		return SCST_C_FATAL_ERROR;
 	}
 
-	my $devices = $self->deviceGroupDevices($group);
-
-	return SCST_C_FATAL_ERROR if (!defined($devices));
-
 	foreach my $_device (@{$devices}) {
 		return TRUE if ($device eq $_device);
 	}
@@ -4393,15 +4407,12 @@ sub targetGroupExists {
 	my $group = shift;
 	my $tgroup = shift;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroupExists(): Device group '$group' does not exist";
-		return undef;
+	my ($tgroups, $errorString) = $self->targetGroups($group);
+
+	if (!defined($tgroups)) {
+		return SCST_C_FATAL_ERROR;
 	}
 
-	my $tgroups = $self->targetGroups($group);
-
-	return SCST_C_FATAL_ERROR if (!defined($tgroups));
-
 	foreach my $_tgroup (@{$tgroups}) {
 		return TRUE if ($tgroup eq $_tgroup);
 	}
@@ -4415,20 +4426,12 @@ sub targetGroupTargetExists {
 	my $tgroup = shift;
 	my $tgt = shift;
 
-	if ($self->deviceGroupExists($group) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargetExists(): Device group '$group' does not exist";
-		return undef;
+	my ($targets, $errorString) = $self->targetGroupTargets($group, $tgroup);
+
+	if (!defined($targets)) {
+		return SCST_C_FATAL_ERROR;
 	}
 
-	if ($self->targetGroupExists($group, $tgroup) != TRUE) {
-		$self->{'err_string'} = "targetGroupTargetExists(): Target group '$tgroup' does not exist";
-		return undef;
-	}
-
-	my $targets = $self->targetGroupTargets($group, $tgroup);
-
-	return SCST_C_FATAL_ERROR if (!defined($targets));
-
 	foreach my $_tgt (@{$targets}) {
 		return TRUE if ($tgt eq $_tgt);
 	}
@@ -4445,24 +4448,26 @@ sub checkLunCreateAttributes {
 
 	return FALSE if (!defined($check));
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
+	my ($available, $errorString) = $self->lunCreateAttributes($driver, $target, $group);
 
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
-
-	if ($group) {
-		$rc = $self->groupExists($driver, $target, $group);
-		return SCST_C_GRP_NO_GROUP if (!$rc);
+	if (!defined($available)) {
+		my $rc = $self->driverExists($driver);
+		return SCST_C_DRV_NO_DRIVER if (!$rc);
 		return $rc if ($rc > 1);
+
+		$rc = $self->targetExists($driver, $target);
+		return SCST_C_TGT_NO_TARGET if (!$rc);
+		return $rc if ($rc > 1);
+
+		if ($group) {
+			$rc = $self->groupExists($driver, $target, $group);
+			return SCST_C_GRP_NO_GROUP if (!$rc);
+			return $rc if ($rc > 1);
+		}
+
+		return SCST_C_FATAL_ERROR;
 	}
 
-	my $available = $self->lunCreateAttributes($driver, $target, $group);
-
-	return SCST_C_FATAL_ERROR if (!defined($available));
-
 	if (ref($check) eq 'HASH') {
 		foreach my $attribute (keys %{$check}) {
 			if (!defined($$available{$attribute})) {
@@ -4486,26 +4491,13 @@ sub lunCreateAttributes {
 	my $available;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "lunCreateAttributes(): Driver '$driver' ".
-		  "is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "lunCreateAttributes(): Target '$target' ".
-		  "is not available";
-		return undef;
-	}
-
 	my $_path;
 
 	if (new_sysfs_interface()) {
 		if (defined($group)) {
 			if ($self->groupExists($driver, $target, $group) != TRUE) {
-				$self->{'err_string'} = "lunCreateAttributes(): Group '$group' ".
-				    "does not exist";
-				return undef;
+				return ("lunCreateAttributes(): Group '$group' ".
+				    "does not exist");
 			}
 
 			$_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
@@ -4521,14 +4513,9 @@ sub lunCreateAttributes {
 			chomp($attribute);
 			$attributes{$attribute} = '';
 		}
+		close $io;
 	} else {
 		if (defined($group)) {
-			if ($self->groupExists($driver, $target, $group) != TRUE) {
-				$self->{'err_string'} = "lunCreateAttributes(): Group '$group' ".
-				    "does not exist";
-				return undef;
-			}
-
 			$_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 					   SCST_GROUPS, $group, SCST_LUNS,
 					   SCST_MGMT_IO);
@@ -4540,9 +4527,21 @@ sub lunCreateAttributes {
 		my $io = new IO::File $_path, O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "lunCreateAttributes(): Unable to open luns mgmt ".
-			    "interface for group '$group': $!";
-			return undef;
+			my $errorString;
+			if ($self->driverExists($driver) != TRUE) {
+				$errorString = "lunCreateAttributes(): Driver '$driver' ".
+				    "is not available";
+			} elsif ($self->targetExists($driver, $target) != TRUE) {
+				$errorString = "lunCreateAttributes(): Target '$target' ".
+				    "is not available";
+			} elsif (defined($group) && $self->groupExists($driver, $target, $group) != TRUE) {
+				$errorString = "lunCreateAttributes(): Group '$group' ".
+				    "does not exist";
+			} else {
+				$errorString = "lunCreateAttributes(): Unable to open luns mgmt ".
+				    "interface for group '$group': $!";
+			}
+			return (undef, $errorString);
 		}
 
 		while (my $in = <$io>) {
@@ -4551,6 +4550,7 @@ sub lunCreateAttributes {
 				$available =~ s/\.$//;
 			}
 		}
+		close $io;
 
 		if ($available) {
 			foreach my $attribute (split(/\,/, $available)) {
@@ -4560,7 +4560,7 @@ sub lunCreateAttributes {
 			}
 		}
 	}
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub checkInitiatorCreateAttributes {
@@ -4572,21 +4572,23 @@ sub checkInitiatorCreateAttributes {
 
 	return FALSE if (!defined($check));
 
-	my $rc = $self->driverExists($driver);
-	return SCST_C_DRV_NO_DRIVER if (!$rc);
-	return $rc if ($rc > 1);
+	my ($available, $errorString) = $self->initiatorCreateAttributes($driver, $target, $group);
 
-	$rc = $self->targetExists($driver, $target);
-	return SCST_C_TGT_NO_TARGET if (!$rc);
-	return $rc if ($rc > 1);
+	if (!defined($available)) {
+		my $rc = $self->driverExists($driver);
+		return SCST_C_DRV_NO_DRIVER if (!$rc);
+		return $rc if ($rc > 1);
 
-	$rc = $self->groupExists($driver, $target, $group);
-	return SCST_C_GRP_NO_GROUP if (!$rc);
-	return $rc if ($rc > 1);
+		$rc = $self->targetExists($driver, $target);
+		return SCST_C_TGT_NO_TARGET if (!$rc);
+		return $rc if ($rc > 1);
 
-	my $available = $self->initiatorCreateAttributes($driver, $target, $group);
+		$rc = $self->groupExists($driver, $target, $group);
+		return SCST_C_GRP_NO_GROUP if (!$rc);
+		return $rc if ($rc > 1);
 
-	return SCST_C_FATAL_ERROR if (!defined($available));
+		return SCST_C_FATAL_ERROR;
+	}
 
 	if (ref($check) eq 'HASH') {
 		foreach my $attribute (keys %{$check}) {
@@ -4611,24 +4613,6 @@ sub initiatorCreateAttributes {
 	my $available;
 	my %attributes;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "initiatorCreateAttributes(): Driver '$driver' ".
-		  "is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "initiatorCreateAttributes(): Target '$target' ".
-		  "is not available";
-		return undef;
-	}
-
-	if ($self->groupExists($driver, $target, $group) != TRUE) {
-		$self->{'err_string'} = "initiatorCreateAttributes(): Group '$group' ".
-		  "does not exist";
-		return undef;
-	}
-
 	if (new_sysfs_interface()) {
 		# Do nothing - there are no initiator attributes (yet).
 	} else {
@@ -4638,9 +4622,21 @@ sub initiatorCreateAttributes {
 				O_RDONLY;
 
 		if (!$io) {
-			$self->{'err_string'} = "initiatorCreateAttributes(): Unable to open initiators mgmt ".
-			    "interface for group '$group': $!";
-			return undef;
+			my $errorString;
+			if ($self->driverExists($driver) != TRUE) {
+				$errorString = "initiatorCreateAttributes(): Driver '$driver' ".
+				    "is not available";
+			} elsif ($self->targetExists($driver, $target) != TRUE) {
+				$errorString = "initiatorCreateAttributes(): Target '$target' ".
+				    "is not available";
+			} elsif ($self->groupExists($driver, $target, $group) != TRUE) {
+				$errorString = "initiatorCreateAttributes(): Group '$group' ".
+				    "does not exist";
+			} else {
+				$errorString = "initiatorCreateAttributes(): Unable to open initiators mgmt ".
+				    "interface for group '$group': $!";
+			}
+			return (undef, $errorString);
 		}
 
 		while (my $in = <$io>) {
@@ -4649,6 +4645,7 @@ sub initiatorCreateAttributes {
 				$available =~ s/\.$//;
 			}
 		}
+		close $io;
 
 		if ($available) {
 			foreach my $attribute (split(/\,/, $available)) {
@@ -4659,7 +4656,7 @@ sub initiatorCreateAttributes {
 		}
 	}
 
-	return \%attributes;
+	return (\%attributes, undef);
 }
 
 sub sessions {
@@ -4668,24 +4665,23 @@ sub sessions {
 	my $target = shift;
 	my %_sessions;
 
-	if ($self->driverExists($driver) != TRUE) {
-		$self->{'err_string'} = "sessions(): Driver '$driver' ".
-		  "is not available";
-		return undef;
-	}
-
-	if ($self->targetExists($driver, $target) != TRUE) {
-		$self->{'err_string'} = "sessions(): Target '$target' ".
-		  "is not available";
-		return undef;
-	}
+	return (undef, "Too few arguments") if (!defined($driver) || !defined($target));
 
 	my $sHandle = new IO::Handle;
 	my $_path = make_path(SCST_TARGETS_DIR(), $driver, $target,
 			      SCST_SESSIONS);
 	if (!(opendir $sHandle, $_path)) {
-		$self->{'err_string'} = "sessions(): Unable to read directory '$_path': $!";
-		return undef;
+		my $errorString;
+		if ($self->driverExists($driver) != TRUE) {
+			$errorString = "sessions(): Driver '$driver' ".
+			    "is not available";
+		} elsif ($self->targetExists($driver, $target) != TRUE) {
+			$errorString = "sessions(): Target '$target' ".
+			    "is not available";
+		} else {
+			$errorString = "sessions(): Unable to read directory '$_path': $!";
+		}
+		return (undef, $errorString);
 	}
 
 	foreach my $session (readdir($sHandle)) {
@@ -4693,8 +4689,7 @@ sub sessions {
 		my $pHandle = new IO::Handle;
 		my $sPath = make_path($_path, $session);
 		if (!(opendir $pHandle, $sPath)) {
-			$self->{'err_string'} = "sessions(): Unable to read directory '$_path': $!";
-			return undef;
+			return (undef, "sessions(): Unable to read directory '$_path': $!");
 		}
 
 		foreach my $attribute (readdir($pHandle)) {
@@ -4730,12 +4725,13 @@ sub sessions {
 						my $io = new IO::File $pPath, O_RDONLY;
 
 						if (!$io) {
-							$self->{'err_string'} = "sessions(): Unable to read ".
-							  "session attribute '$attribute': $!";
-							return undef;
+							return (undef,
+								"sessions(): Unable to read ".
+								"session attribute '$attribute': $!");
 						}
 
 						my $value = <$io>;
+						close $io;
 						chomp $value;
 
 						$_sessions{$session}->{$attribute}->{'value'} = $value;
@@ -4744,9 +4740,11 @@ sub sessions {
 				}
 			}
 		}
+		close $pHandle;
 	}
+	close $sHandle;
 
-	return \%_sessions;
+	return (\%_sessions, undef);
 }
 
 sub closeSession {
@@ -4755,7 +4753,7 @@ sub closeSession {
 	my $target = shift;
 	my $session = shift;
 
-	my $sessions = $self->sessions($driver, $target);
+	my ($sessions, $errorString) = $self->sessions($driver, $target);
 
 	return SCST_C_NO_SESSION if (!defined($$sessions{$session}));
 
@@ -4766,18 +4764,17 @@ sub closeSession {
 			     SCST_SESSIONS, $session, 'force_close');
 
 	my $io = new IO::File $path, O_WRONLY;
-
-	my $cmd = "1";
-
-	my $bytes;
-
-	if ($self->{'debug'}) {
-		print "DBG($$): $cmd\n";
-	} else {
-		$bytes = _syswrite($io, $cmd, length($cmd));
+	if ($io) {
+		my $cmd = "1";
+		my $bytes;
+		if ($self->{'debug'}) {
+			print "DBG($$): $cmd\n";
+		} else {
+			$bytes = _syswrite($io, $cmd, length($cmd));
+		}
+		close $io;
+		return FALSE if ($self->{'debug'} || $bytes);
 	}
-
-	return FALSE if ($self->{'debug'} || $bytes);
 	return SCST_C_SESSION_CLOSE_FAIL;
 }
 
@@ -4788,8 +4785,7 @@ sub sgvStats {
 	my $sHandle = new IO::Handle;
 	my $_path = SCST_SGV_DIR();
 	if (!(opendir $sHandle, $_path)) {
-		$self->{'err_string'} = "svgStats(): Unable to read directory '$_path': $!";
-		return undef;
+		return (undef, "svgStats(): Unable to read directory '$_path': $!");
 	}
 
 	foreach my $stat (readdir($sHandle)) {
@@ -4800,8 +4796,7 @@ sub sgvStats {
 		if (-d $sPath) {
 			my $lHandle = new IO::Handle;
 			if (!(opendir $lHandle, $sPath)) {
-				$self->{'err_string'} = "svgStats(): Unable to read directory '$sPath': $!";
-				return undef;
+				return (undef, "svgStats(): Unable to read directory '$sPath': $!");
 			}
 
 			foreach my $lief (readdir($lHandle)) {
@@ -4810,50 +4805,46 @@ sub sgvStats {
 				my $io = new IO::File $pPath, O_RDONLY;
 
 				if (!$io) {
-					$self->{'err_string'} = "sgvStats(): Unable to read ".
-					  "sgv stat '$stat/$lief': $!";
-					return undef;
+					return (undef, "sgvStats(): Unable to read ".
+					  "sgv stat '$stat/$lief': $!");
 				}
 
 				my $buffer;
 				while (my $value = <$io>) {
 					$buffer .= $value;
 				}
+				close $io;
 
 				$stats{$stat}->{$lief} = $buffer;
 			}
+			close $lHandle;
 		} else {
 			my $io = new IO::File $sPath, O_RDONLY;
 
 			if (!$io) {
-				$self->{'err_string'} = "sgvStats(): Unable to read ".
-				  "sgv stat '$stat': $!";
-				return undef;
+				return (undef, "sgvStats(): Unable to read ".
+					"sgv stat '$stat': $!");
 			}
 
 			my $buffer;
 			while (my $value = <$io>) {
 				$buffer .= $value;
 			}
+			close $io;
 
 			$stats{$stat} = $buffer;
 		}
 	}
+	close $sHandle;
 
-	return \%stats;
+	return (\%stats, undef);
 }
 
 sub errorString {
 	my $self = shift;
 	my $rc = shift;
 
-	return $VERBOSE_ERROR{$rc} if (defined($rc));
-	return undef if (!$self->{'err_string'});
-
-	my $string = $self->{'err_string'};
-	$self->{'err_string'} = undef;
-
-	return $string;
+	return defined($rc) ? $VERBOSE_ERROR{$rc} : undef;
 }
 
 # Read from the SCST sysfs file $1. Return either the data read or undef if
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/01-start-scst.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/01-start-scst.t
new file mode 100644
index 000000000..cc857c0e7
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/01-start-scst.t
@@ -0,0 +1,27 @@
+#!perl
+
+use strict;
+use Test;
+
+BEGIN {
+    plan tests => ($> == 0) ? 3 : 0;
+}
+
+if ($> == 0) {
+    ok(system("killall iscsi-scstd >/dev/null 2>&1; " .
+	      "modprobe -r scst_local; " .
+	      "modprobe -r iscsi-scst; " .
+	      "modprobe -r ib_srpt; " .
+	      "modprobe -r qla2x00tgt; " .
+	      "modprobe -r qla2xxx_scst; " .
+	      "modprobe -r scst_vdisk"), 0);
+
+    ok(!(-d "/sys/module/scst"));
+
+    ok(system("modprobe scst_local add_default_tgt=0 && " .
+	      "modprobe iscsi-scst && " .
+	      "modprobe ib_srpt && " .
+	      "modprobe qla2x00tgt && " .
+	      "modprobe scst_vdisk && " .
+	      "iscsi-scstd"), 0);
+}
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/02-scst-attr.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/02-scst-attr.t
new file mode 100644
index 000000000..267423138
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/02-scst-attr.t
@@ -0,0 +1,46 @@
+#!perl
+
+use strict;
+use Test;
+
+BEGIN {
+    plan tests => 6 + ($> == 0 ? 4 : 0);
+}
+
+use SCST::SCST;
+
+sub getScstThreadCount {
+    my $SCST = shift;
+    my ($scstAttributes, $errorString) = $SCST->scstAttributes();
+    my $threadHash = $scstAttributes->{'threads'};
+    return exists($threadHash->{'keys'}) ? $threadHash->{'keys'}->{'0'}->{'value'} : $threadHash->{'value'};
+}
+
+my $_DEBUG_ = 0;
+
+my $SCST = eval { new SCST::SCST($_DEBUG_) };
+die("Creation of SCST object failed") if (!defined($SCST));
+
+ok($SCST->setScstAttribute(), 1);
+
+ok($SCST->setScstAttribute('no-such-attribute'), 1);
+
+ok($SCST->setScstAttribute('no-such-attribute', '1'),
+   $SCST->SCST_C_BAD_ATTRIBUTES);
+
+ok($SCST->setScstAttribute('last_sysfs_mgmt_res', '1'),
+   $SCST->SCST_C_ATTRIBUTE_STATIC);
+
+my $threads = getScstThreadCount($SCST);
+ok(ref(\$threads), "SCALAR");
+ok(defined($threads));
+
+if ($> == 0) {
+    ok($SCST->setScstAttribute('threads', $threads + 1), 0);
+
+    ok(getScstThreadCount($SCST), $threads + 1);
+
+    ok($SCST->setScstAttribute('threads', $threads), 0);
+
+    ok(getScstThreadCount($SCST), $threads);
+}
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/03-targets.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/03-targets.t
new file mode 100644
index 000000000..28db54d06
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/03-targets.t
@@ -0,0 +1,365 @@
+#!perl
+
+use strict;
+use Test;
+
+BEGIN {
+    plan tests => 177;
+}
+
+use Data::Dumper;
+use SCST::SCST;
+
+sub addTargets {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->targets('no-such-driver')),
+       Dumper(undef, "targets(): Driver 'no-such-driver' is not available"));
+
+    my ($drivers, $errorString) = $SCST->drivers();
+    my %drivers = map { $_ => 1 } @{$drivers};
+    ok(exists($drivers{'iscsi'}));
+    ok(exists($drivers{'scst_local'}));
+
+    my $all_hw_tgt = 1;
+    for my $driver (@{$drivers}) {
+	my ($targets, $errorString) = $SCST->targets($driver);
+	for my $target (@{$targets}) {
+	    if ($SCST->targetType($driver, $target) !=
+		$SCST::SCST::TGT_TYPE_HARDWARE) {
+		$all_hw_tgt = undef;
+	    }
+	}
+    }
+    ok($all_hw_tgt);
+
+    ok(Dumper($SCST->targets()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->targets('no-such-driver')),
+       Dumper(undef, "targets(): Driver 'no-such-driver' is not available"));
+    ok(Dumper($SCST->targets('scst_local')), Dumper([], undef));
+    ok(Dumper($SCST->targets('iscsi')), Dumper([], undef));
+
+    ok($SCST->addVirtualTarget('no-such-driver', ''),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->removeVirtualTarget('no-such-driver', ''),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->addVirtualTarget('scst_local', 'local1'), 0);
+    ok(Dumper($SCST->targetType()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->targetType('scst_local')),
+       Dumper(undef, "Too few arguments"));
+    ok($SCST->targetType('scst_local', 'no-such-target'),
+       $SCST::SCST::TGT_TYPE_VIRTUAL);
+    ok($SCST->targetType('scst_local', 'local1'),
+       $SCST::SCST::TGT_TYPE_VIRTUAL);
+    ok(Dumper($SCST->targets('scst_local')), Dumper(['local1'], undef));
+    ok($SCST->removeVirtualTarget('scst_local', 'local2'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok(Dumper($SCST->targets('scst_local')), Dumper(['local1'], undef));
+    ok($SCST->removeVirtualTarget('scst_local', 'local1'), 0);
+    ok(Dumper($SCST->targets('scst_local')), Dumper([], undef));
+    ok($SCST->addVirtualTarget('scst_local', 'local1',
+			       { 'session_name' => 'local1' }), 0);
+    ok($SCST->addVirtualTarget('scst_local', 'local2',
+			       { 'session_name' => 'local2' }), 0);
+    ok(Dumper($SCST->targets('scst_local')),
+       Dumper(['local1', 'local2'], undef));
+
+    ok($SCST->targetExists(), 0);
+    ok($SCST->targetExists('no-such-driver'), 0);
+    ok($SCST->targetExists('no-such-driver', ''), 0);
+    ok($SCST->targetExists('scst_local', 'no-such-target'), 0);
+    ok($SCST->targetExists('scst_local', '.'), 0);
+    ok($SCST->targetExists('scst_local', '..'), 0);
+    ok($SCST->targetExists('scst_local', 'module'), 0);
+    ok($SCST->targetExists('scst_local', 'local1'), 1);
+}
+
+sub sessTest {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->sessions()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->sessions('scst_local')),
+       Dumper(undef, "Too few arguments"));
+    my ($s, $errorString) = $SCST->sessions('scst_local', 'local1');
+    ok(Dumper(sort(keys(%$s))), Dumper('local1'));
+    ok($s->{'local1'}->{'commands'}->{'value'}, '0');
+}
+
+sub driverDynamicAttributesTest {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->driverDynamicAttributes()),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->driverDynamicAttributes('no-such-driver')),
+       Dumper(undef, "driverDynamicAttributes(): Driver 'no-such-driver' is " .
+	       "not available"));
+    ok(Dumper($SCST->driverDynamicAttributes('scst_local')),
+       Dumper({}, undef));
+}
+
+sub iniGrpTest {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->groups()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->groups('scst_local')),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->groups('scst_local', 'local1')), Dumper([], undef));
+
+    ok($SCST->addGroup(), $SCST->SCST_C_GRP_ADD_FAIL);
+    ok($SCST->addGroup('no-such-driver', 'local1', 'group1'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->addGroup('scst_local', 'no-such-target', 'group1'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->addGroup('scst_local', 'local1', 'group1'), 0);
+    ok($SCST->addGroup('scst_local', 'local1', 'group1'),
+       $SCST->SCST_C_GRP_EXISTS);
+    ok($SCST->addGroup('scst_local', 'local1', 'group2'), 0);
+    ok($SCST->addGroup('scst_local', 'local1', 'group3'), 0);
+    ok(Dumper($SCST->groups('scst_local', 'local1')),
+       Dumper(['group1', 'group2', 'group3'], undef));
+
+    ok($SCST->groupExists(), 0);
+    ok($SCST->groupExists('no-such-driver', '', ''), 0);
+    ok($SCST->groupExists('scst_local', 'no-such-target', ''), 0);
+    ok($SCST->groupExists('scst_local', 'local1', 'no-such-group'), 0);
+    ok($SCST->groupExists('scst_local', 'local1', 'group1'), 1);
+
+    ok($SCST->removeGroup(), $SCST->SCST_C_GRP_REM_FAIL);
+    ok($SCST->removeGroup('no-such-driver', 'local1', 'group1'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->removeGroup('scst_local', 'no-such-target', 'group1'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->removeGroup('scst_local', 'local1', 'group1'), 0);
+    ok($SCST->removeGroup('scst_local', 'local1', 'group1'),
+       $SCST->SCST_C_GRP_NO_GROUP);
+    ok($SCST->removeGroup('scst_local', 'local1', 'group2'), 0);
+    ok($SCST->removeGroup('scst_local', 'local1', 'group3'), 0);
+    ok(Dumper($SCST->groups('scst_local', 'local1')), Dumper([], undef));
+
+    ok($SCST->addGroup('scst_local', 'local1', 'group1'), 0);
+    ok($SCST->addInitiator('scst_local', 'local1', 'group1'),
+       $SCST->SCST_C_GRP_ADD_INI_FAIL);
+    ok($SCST->addInitiator('no-such-driver', 'local1', 'group1', 'ini1'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->addInitiator('scst_local', 'no-such-target', 'group1', 'ini1'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->addInitiator('scst_local', 'local1', 'no-such-group', 'ini1'),
+       $SCST->SCST_C_GRP_NO_GROUP);
+    ok($SCST->addInitiator('scst_local', 'local1', 'group1', 'ini1'), 0);
+    ok($SCST->addInitiator('scst_local', 'local1', 'group1', 'ini2'), 0);
+    ok($SCST->addInitiator('scst_local', 'local1', 'group1', 'ini1'),
+       $SCST->SCST_C_GRP_INI_EXISTS);
+    ok(Dumper($SCST->initiators()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->initiators('scst_local')),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->initiators('scst_local', 'local1')),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->initiators('scst_local', 'local1', 'group1')),
+       Dumper(['ini1', 'ini2'], undef));
+
+    ok($SCST->initiatorExists(), 0);
+    ok($SCST->initiatorExists('no-such-driver', '', '', ''), 0);
+    ok($SCST->initiatorExists('scst_local', 'no-such-target', '', ''), 0);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'no-such-group', ''), 0);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'group1', 'no-such-ini'),
+       0);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'group1', 'ini1'), 1);
+
+    ok($SCST->addGroup('scst_local', 'local1', 'group2'), 0);
+    ok($SCST->moveInitiator('scst_local', 'local1', 'group1', 'group2', 'ini1'),
+       0);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'group1', 'ini1'), 0);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'group2', 'ini1'), 1);
+    ok($SCST->moveInitiator('scst_local', 'local1', 'group2', 'group1', 'ini1'),
+       0);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'group1', 'ini1'), 1);
+    ok($SCST->initiatorExists('scst_local', 'local1', 'group2', 'ini1'), 0);
+
+    ok($SCST->removeGroup('scst_local', 'local1', 'group2'), 0);
+    ok($SCST->removeInitiator('no-such-driver', 'local1', 'group1'),
+       $SCST->SCST_C_GRP_REM_INI_FAIL);
+    ok($SCST->removeInitiator('no-such-driver', 'local1', 'group1', 'ini1'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->removeInitiator('scst_local', 'no-such-target', 'group1', 'ini1'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->removeInitiator('scst_local', 'local1', 'no-such-group', 'ini1'),
+       $SCST->SCST_C_GRP_NO_GROUP);
+    ok($SCST->removeInitiator('scst_local', 'local1', 'group1', 'ini1'), 0);
+    ok($SCST->removeInitiator('scst_local', 'local1', 'group1', 'ini2'), 0);
+    ok($SCST->removeInitiator('scst_local', 'local1', 'group1', 'ini2'),
+	$SCST->SCST_C_GRP_NO_INI);
+    ok(Dumper($SCST->initiators('scst_local', 'local1', 'group1')),
+       Dumper([], undef));
+    ok($SCST->removeGroup('scst_local', 'local1', 'group1'), 0);
+}
+
+sub lunReadOnly {
+    my $SCST = shift;
+    my $driver = shift;
+    my $target = shift;
+    my $lun = shift;
+
+    my ($a, $errorString) = $SCST->lunAttributes($driver, $target, $lun);
+    my $roHash = $a->{'read_only'};
+    return exists($roHash->{'keys'}) ? $roHash->{'keys'}->{'0'}->{'value'} :
+	$roHash->{'value'};
+}
+
+sub lunTest {
+    my $SCST = shift;
+
+    ok($SCST->openDevice("no-such-handler", "disk01", { }),
+       $SCST->SCST_C_HND_NO_HANDLER);
+    ok($SCST->openDevice("vdisk_fileio", "disk01", undef),
+       $SCST->SCST_C_DEV_OPEN_FAIL);
+    ok($SCST->openDevice("vdisk_fileio", "disk01", { }),
+       $SCST->SCST_C_DEV_OPEN_FAIL);
+    ok($SCST->openDevice("vdisk_fileio", "disk01",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+    ok(Dumper($SCST->devicesByHandler("vdisk_fileio")),
+       Dumper(["disk01"], undef));
+    ok($SCST->openDevice("vdisk_fileio", "disk01",
+			 { 'filename' => '/proc/cpuinfo' }),
+       $SCST->SCST_C_DEV_EXISTS);
+    ok($SCST->openDevice("vdisk_fileio", "disk02",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 0),
+       $SCST->SCST_C_TGT_ADD_LUN_FAIL);
+    ok($SCST->addLun('scst_local', 'local3', 'disk01', 0, { }),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 0, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk02', 1, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 2, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk02', 3, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 3, { }),
+       $SCST->SCST_C_TGT_LUN_EXISTS);
+
+    ok($SCST->lunExists(), 0);
+    ok($SCST->lunExists('scst_local'), 0);
+    ok($SCST->lunExists('scst_local', 'local1'), 0);
+    ok($SCST->lunExists('no-such-driver', 'local1', 0),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->lunExists('scst_local', 'no-such-target', 0),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->lunExists('scst_local', 'local1', 99), 0);
+    ok($SCST->lunExists('scst_local', 'local1', 0), 1);
+
+    ok($SCST->addGroup('scst_local', 'local1', 'group1'), 0);
+    ok($SCST->addInitiator('scst_local', 'local1', 'group1', 'ini1'), 0);
+
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 0, undef, 'group1'),
+       $SCST->SCST_C_GRP_ADD_LUN_FAIL);
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 0, { }, 'group1'), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk02', 2, { }, 'group1'), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 4, { }, 'group1'), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk02', 6, { }, 'group1'), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 6, { }, 'group1'),
+       $SCST->SCST_C_GRP_LUN_EXISTS);
+
+    ok($SCST->lunExists('no-such-driver', 'local1', 0, 'group1'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->lunExists('scst_local', 'no-such-target', 0, 'group1'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->lunExists('scst_local', 'local1', 99, 'group1'), 0);
+    ok($SCST->lunExists('scst_local', 'local1', 0, 'no-such-group'),
+       $SCST->SCST_C_GRP_NO_GROUP);
+    ok($SCST->lunExists('scst_local', 'local1', 0, 'group1'), 1);
+
+    ok(Dumper($SCST->luns()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->luns('scst_local')), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->luns('no-such-driver', 'local1')),
+       Dumper(undef, "luns(): Driver 'no-such-driver' is not available"));
+    ok(Dumper($SCST->luns('scst_local', 'no-such-target')),
+       Dumper(undef, "luns(): Target 'no-such-target' is not available"));
+    ok(Dumper($SCST->luns('scst_local', 'local1')),
+       Dumper({ '0' => 'disk01', '1' => 'disk02', '2' => 'disk01',
+		'3' => 'disk02' }, undef));
+    ok(Dumper($SCST->luns('scst_local', 'local1', 'group1')),
+       Dumper({ '0' => 'disk01', '2' => 'disk02', '4' => 'disk01',
+		'6' => 'disk02' }, undef));
+
+    ok(lunReadOnly($SCST, 'scst_local', 'local1', 0), '0');
+    ok($SCST->setLunAttribute(), $SCST->SCST_C_LUN_SETATTR_FAIL);
+    ok($SCST->setLunAttribute('no-such-driver', 'local1', 0, 'read_only', '1'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->setLunAttribute('scst_local', 'no-such-target', 0, 'read_only', '1'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->setLunAttribute('scst_local', 'local1', 99, 'read_only', '1'),
+       $SCST->SCST_C_TGT_NO_LUN);
+    ok($SCST->setLunAttribute('scst_local', 'local1', 0, 'read_only', '1'),
+       $SCST->SCST_C_LUN_ATTRIBUTE_STATIC);
+    ok(lunReadOnly($SCST, 'scst_local', 'local1', 0), '0');
+    ok(lunReadOnly($SCST, 'scst_local', 'local1', 0, 'group1'), '0');
+    ok($SCST->setLunAttribute('scst_local', 'local1', 0, 'read_only', '1', 'no-such-group'),
+       $SCST->SCST_C_GRP_NO_GROUP);
+    ok($SCST->setLunAttribute('scst_local', 'local1', 99, 'read_only', '1', 'group1'),
+       $SCST->SCST_C_GRP_NO_LUN);
+    ok($SCST->setLunAttribute('scst_local', 'local1', 0, 'read_only', '1', 'group1'),
+       $SCST->SCST_C_LUN_ATTRIBUTE_STATIC);
+    ok(lunReadOnly($SCST, 'scst_local', 'local1', 0, 'group1'), '0');
+
+    ok($SCST->replaceLun('scst_local', 'local1', 0, 'disk02', {}), 0);
+    ok(Dumper($SCST->luns('scst_local', 'local1')),
+       Dumper({ '0' => 'disk02', '1' => 'disk02', '2' => 'disk01',
+		'3' => 'disk02' }, undef));
+    ok($SCST->replaceLun('scst_local', 'local1', 0, 'disk01', {}), 0);
+    ok(Dumper($SCST->luns('scst_local', 'local1')),
+       Dumper({ '0' => 'disk01', '1' => 'disk02', '2' => 'disk01',
+		'3' => 'disk02' }, undef));
+
+    ok($SCST->clearLuns(undef, undef), $SCST->SCST_C_TGT_CLR_LUN_FAIL);
+    ok($SCST->clearLuns(undef, undef, 'group1'),
+       $SCST->SCST_C_GRP_CLR_LUN_FAIL);
+    ok($SCST->removeLun(undef, undef, undef), $SCST->SCST_C_TGT_ADD_LUN_FAIL);
+    ok($SCST->removeLun('no-such-driver', 'local1', '0'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->removeLun('scst_local', 'no-such-target', '0'),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->removeLun(undef, undef, undef, 'group1'),
+       $SCST->SCST_C_GRP_REM_LUN_FAIL);
+    ok($SCST->removeLun('scst_local', 'local1', '4'), $SCST->SCST_C_TGT_NO_LUN);
+    ok($SCST->removeLun('scst_local', 'local1', '8', 'group1'),
+       $SCST->SCST_C_GRP_NO_LUN);
+    ok($SCST->clearLuns('scst_local', 'local1'), 0);
+    ok(Dumper($SCST->luns('scst_local', 'local1')), Dumper({ }, undef));
+    ok(Dumper($SCST->luns('scst_local', 'local1', 'group1')),
+       Dumper({ '0' => 'disk01', '2' => 'disk02', '4' => 'disk01',
+		'6' => 'disk02' }, undef));
+    ok($SCST->removeLun('scst_local', 'local1', '4', 'group1'), 0);
+    ok(Dumper($SCST->luns('scst_local', 'local1', 'group1')),
+       Dumper({ '0' => 'disk01', '2' => 'disk02', '6' => 'disk02' }, undef));
+    ok($SCST->clearLuns('scst_local', 'local1', 'group1'), 0);
+    ok(Dumper($SCST->luns('scst_local', 'local1', 'group1')),
+       Dumper({ }, undef));
+
+    ok($SCST->removeInitiator('scst_local', 'local1', 'group1', 'ini1'), 0);
+    ok($SCST->removeGroup('scst_local', 'local1', 'group1'), 0);
+
+    ok($SCST->closeDevice("no-such-handler", "disk01"),
+       $SCST->SCST_C_HND_NO_HANDLER);
+    ok($SCST->closeDevice("vdisk_fileio", "disk02"), 0);
+    ok($SCST->closeDevice("vdisk_fileio", "disk01"), 0);
+    ok($SCST->closeDevice("vdisk_fileio", "disk01"),
+       $SCST->SCST_C_DEV_NO_DEVICE);
+}
+
+sub remTargets {
+    my $SCST = shift;
+
+    ok($SCST->removeVirtualTarget('scst_local', 'local2'), 0);
+    ok($SCST->removeVirtualTarget('scst_local', 'local1'), 0);
+    ok(Dumper($SCST->targets('scst_local')), Dumper([], undef));
+}
+
+my $_DEBUG_ = 0;
+
+my $SCST = eval { new SCST::SCST($_DEBUG_) };
+die("Creation of SCST object failed") if (!defined($SCST));
+
+addTargets($SCST);
+sessTest($SCST);
+driverDynamicAttributesTest($SCST);
+iniGrpTest($SCST);
+lunTest($SCST);
+remTargets($SCST);
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/04-alua.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/04-alua.t
new file mode 100644
index 000000000..c2b39a7d1
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/04-alua.t
@@ -0,0 +1,143 @@
+#!perl
+
+use strict;
+use Test;
+
+BEGIN {
+    plan tests => 62;
+}
+
+use Data::Dumper;
+use SCST::SCST;
+
+sub setup {
+    my $SCST = shift;
+
+    my ($drivers, $errorString) = $SCST->drivers();
+    my %drivers = map { $_ => 1 } @{$drivers};
+    ok(exists($drivers{'iscsi'}));
+    ok(exists($drivers{'scst_local'}));
+
+    ok($SCST->openDevice("vdisk_fileio", "disk01",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+    ok($SCST->openDevice("vdisk_fileio", "disk02",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+    ok($SCST->openDevice("vdisk_fileio", "disk03",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+    ok($SCST->openDevice("vdisk_fileio", "disk04",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+
+    ok($SCST->addVirtualTarget('scst_local', 'local1'), 0);
+
+    ok($SCST->addLun('scst_local', 'local1', 'disk01', 0, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk02', 1, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk03', 2, { }), 0);
+    ok($SCST->addLun('scst_local', 'local1', 'disk04', 3, { }), 0);
+}
+
+sub test {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->deviceGroups()), Dumper([], undef));
+
+    ok($SCST->addDeviceGroup('dg1'), 0);
+    ok($SCST->addDeviceGroup('dg2'), 0);
+    ok($SCST->addDeviceGroup('dg3'), 0);
+    ok($SCST->addDeviceGroup('dg4'), 0);
+
+    ok(Dumper($SCST->deviceGroups()),
+       Dumper(['dg1', 'dg2', 'dg3', 'dg4'], undef));
+
+    ok(Dumper($SCST->deviceGroupDevices()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->deviceGroupDevices('dg1')), Dumper([], undef));
+    ok($SCST->addDeviceGroupDevice('dg1', 'disk01'), 0);
+    ok($SCST->addDeviceGroupDevice('dg1', 'disk01'),
+       $SCST->SCST_C_DGRP_DEVICE_EXISTS);
+    ok($SCST->addDeviceGroupDevice('dg2', 'disk02'), 0);
+    ok($SCST->addDeviceGroupDevice('dg2', 'disk01'),
+       $SCST->SCST_C_DGRP_DEVICE_OTHER);
+    ok($SCST->addDeviceGroupDevice('dg3', 'disk03'), 0);
+    ok($SCST->addDeviceGroupDevice('dg4', 'disk04'), 0);
+    ok(Dumper($SCST->deviceGroupDevices('dg1')), Dumper(['disk01'], undef));
+    ok(Dumper($SCST->deviceGroupDevices('dg2')), Dumper(['disk02'], undef));
+    ok(Dumper($SCST->deviceGroupDevices('dg3')), Dumper(['disk03'], undef));
+    ok(Dumper($SCST->deviceGroupDevices('dg4')), Dumper(['disk04'], undef));
+
+    ok(Dumper($SCST->targetGroups()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->targetGroups('no-such-device-group')),
+       Dumper(undef, "targetGroups(): Device group 'no-such-device-group'" .
+	      " does not exist"));
+    ok(Dumper($SCST->targetGroups('dg1')), Dumper([], undef));
+
+    ok(Dumper($SCST->targetGroupTargets()), Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->targetGroupTargets('no-such-device-group')),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->targetGroupTargets('no-such-device-group', 'tg1')),
+       Dumper(undef, "targetGroupTargets(): Device group 'no-such-device-".
+	      "group' does not exist"));
+    ok(Dumper($SCST->targetGroupTargets('dg1', 'no-such-target-group')),
+       Dumper(undef, "targetGroupTargets(): Target group 'no-such-target-".
+	      "group' does not exist"));
+    ok(Dumper($SCST->targetGroupTargets('dg1', 'tg1')), Dumper(undef,
+	      "targetGroupTargets(): Target group 'tg1' does not exist"));
+    ok($SCST->addTargetGroup(), $SCST->SCST_C_DGRP_ADD_GRP_FAIL);
+    ok($SCST->addTargetGroup('no-such-device-group', 'tg1'),
+       $SCST->SCST_C_DEV_GRP_NO_GROUP);
+    ok($SCST->addTargetGroup('dg1', 'tg1'), 0);
+    ok($SCST->addTargetGroup('dg1', 'tg1'), $SCST->SCST_C_DGRP_GROUP_EXISTS);
+    ok($SCST->addTargetGroup('dg1', 'tg2'), 0);
+
+    my ($tga, $errorString) = $SCST->targetGroupAttributes('dg1', 'tg1');
+    ok(Dumper($tga->{'group_id'}),
+       Dumper({ 'keys' => { '0' => { 'value' => '0' } }, 'static' => 0 }));
+    ok($SCST->setTargetGroupAttribute('dg1', 'tg1', 'group_id', 7), 0);
+    ($tga, $errorString) = $SCST->targetGroupAttributes('dg1', 'tg1');
+    ok(Dumper($tga->{'group_id'}),
+       Dumper({ 'keys' => { '0' => { 'value' => '7' } }, 'static' => 0 }));
+
+    ok($SCST->addTargetGroupTarget(), $SCST->SCST_C_TGRP_ADD_TGT_FAIL);
+    ok($SCST->addTargetGroupTarget('no-such-device-group', 'tg1', 'tgt1'),
+       $SCST->SCST_C_DEV_GRP_NO_GROUP);
+    ok($SCST->addTargetGroupTarget('dg1', 'no-such-target-group', 'tgt1'),
+       $SCST->SCST_C_DGRP_NO_GROUP);
+    ok($SCST->addTargetGroupTarget('dg1', 'tg1', 'tgt1'), 0);
+    ok($SCST->addTargetGroupTarget('dg1', 'tg1', 'tgt1'),
+       $SCST->SCST_C_TGRP_TGT_EXISTS);
+    ok($SCST->addTargetGroupTarget('dg1', 'tg2', 'tgt2'), 0);
+
+    my $tgta;
+    ($tgta, $errorString) =
+	$SCST->targetGroupTargetAttributes('dg1', 'tg1', 'tgt1');
+    ok(Dumper($tgta->{'rel_tgt_id'}),
+       Dumper({ 'keys' => { '0' => { 'value' => '0' } }, 'static' => 0 }));
+    ok($SCST->setTargetGroupTargetAttribute('dg1', 'tg1', 'tgt1', 'rel_tgt_id',
+					    8), 0);
+    ($tgta, $errorString) =
+	$SCST->targetGroupTargetAttributes('dg1', 'tg1', 'tgt1');
+    ok(Dumper($tgta->{'rel_tgt_id'}),
+       Dumper({ 'keys' => { '0' => { 'value' => '8' } }, 'static' => 0 }));
+
+    ok($SCST->removeDeviceGroup('dg1'), 0);
+    ok($SCST->removeDeviceGroup('dg2'), 0);
+    ok($SCST->removeDeviceGroup('dg3'), 0);
+    ok($SCST->removeDeviceGroup('dg4'), 0);
+
+    ok(Dumper($SCST->deviceGroups()), Dumper([], undef));
+}
+
+sub teardown {
+    my $SCST = shift;
+
+    ok($SCST->removeVirtualTarget('scst_local', 'local1'), 0);
+    ok($SCST->closeDevice("vdisk_fileio", "disk01"), 0);
+    ok($SCST->closeDevice("vdisk_fileio", "disk02"), 0);
+}
+
+my $_DEBUG_ = 0;
+
+my $SCST = eval { new SCST::SCST($_DEBUG_) };
+die("Creation of SCST object failed") if (!defined($SCST));
+
+setup($SCST);
+test($SCST);
+teardown($SCST);
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/05-dynattr.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/05-dynattr.t
new file mode 100644
index 000000000..02ff569ca
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/05-dynattr.t
@@ -0,0 +1,160 @@
+#!perl
+
+use strict;
+use Test;
+
+BEGIN {
+    plan tests => 55;
+}
+
+use Data::Dumper;
+use SCST::SCST;
+
+sub setup {
+    my $SCST = shift;
+
+    my ($drivers, $errorString) = $SCST->drivers();
+    my %drivers = map { $_ => 1 } @{$drivers};
+    ok(exists($drivers{'iscsi'}));
+    ok(exists($drivers{'scst_local'}));
+
+    ok($SCST->openDevice("vdisk_fileio", "disk01",
+			 { 'filename' => '/proc/cpuinfo' }), 0);
+
+    ok($SCST->addVirtualTarget('iscsi', 'tgt1'), 0);
+
+    ok($SCST->addLun('iscsi', 'tgt1', 'disk01', 0, { }), 0);
+}
+
+sub testDriverDynAttr {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->driverDynamicAttributes()),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->driverDynamicAttributes('no-such-driver')),
+       Dumper(undef, "driverDynamicAttributes(): Driver 'no-such-driver' is " .
+	      "not available"));
+    ok(Dumper($SCST->driverDynamicAttributes('scst_local')), Dumper({}, undef));
+    ok(Dumper($SCST->driverDynamicAttributes('iscsi')),
+       Dumper({ 'IncomingUser' => '', 'OutgoingUser' => '' }, undef));
+    ok($SCST->checkDriverDynamicAttributes('no-such-driver'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->checkDriverDynamicAttributes('no-such-driver', { }),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->checkDriverDynamicAttributes('scst_local', { }), 0);
+    ok($SCST->checkDriverDynamicAttributes('iscsi', { }), 0);
+    ok($SCST->checkDriverDynamicAttributes('iscsi',
+					   { 'IncomingUser' => ''}), 0);
+    ok($SCST->checkDriverDynamicAttributes('iscsi',
+					   { 'IncomingUser' => '',
+					     'OutgoingUser' => '' }), 0);
+    ok($SCST->checkDriverDynamicAttributes('iscsi',
+					   { 'IncomingUser' => '',
+					     'OutgoingUser' => '',
+					     'NoSuchAttribute' => '' }), 1);
+
+    ok($SCST->addDriverDynamicAttribute(), $SCST->SCST_C_DRV_ADDATTR_FAIL);
+    ok($SCST->addDriverDynamicAttribute('no-such-driver', '', ''),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->addDriverDynamicAttribute('iscsi', 'no-such-attribute', ''),
+       $SCST->SCST_C_DRV_BAD_ATTRIBUTES);
+    ok($SCST->addDriverDynamicAttribute('iscsi', 'IncomingUser',
+					'bar 12CharSecret'), 0);
+    ok($SCST->addDriverDynamicAttribute('iscsi', 'IncomingUser',
+					'joe 12charsecret'), 0);
+    my ($da, $errorString) = $SCST->driverAttributes('iscsi');
+    ok(Dumper($da->{'IncomingUser'}),
+       Dumper({ 'keys' => { '0' => { 'value' => 'bar 12CharSecret' },
+	                    '1' => { 'value' => 'joe 12charsecret' } },
+	        'static' => 0 }));
+    ok($SCST->removeDriverDynamicAttribute(), $SCST->SCST_C_DRV_REMATTR_FAIL);
+    ok($SCST->removeDriverDynamicAttribute('no-such-driver', '', ''),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->removeDriverDynamicAttribute('iscsi', 'no-such-attribute', ''),
+       $SCST->SCST_C_DRV_BAD_ATTRIBUTES);
+    ok($SCST->removeDriverDynamicAttribute('iscsi', 'IncomingUser',
+					   'joe 12charsecret'), 0);
+    ok($SCST->removeDriverDynamicAttribute('iscsi', 'IncomingUser',
+					   'bar 12CharSecret'), 0);
+    ($da, $errorString) = $SCST->driverAttributes('iscsi');
+    ok(!exists($da->{'IncomingUser'}));
+}
+
+sub testTargetDynAttr {
+    my $SCST = shift;
+
+    ok(Dumper($SCST->targetDynamicAttributes()),
+       Dumper(undef, "Too few arguments"));
+    ok(Dumper($SCST->targetDynamicAttributes('no-such-driver')),
+       Dumper(undef, "targetDynamicAttributes(): Driver 'no-such-driver' is" .
+	      " not available"));
+    ok(Dumper($SCST->targetDynamicAttributes('scst_local')), Dumper({}, undef));
+    ok(Dumper($SCST->targetDynamicAttributes('iscsi')),
+       Dumper({ 'IncomingUser' => '',
+		'OutgoingUser' => '',
+		'allowed_portal' => '' }, undef));
+    ok($SCST->checkTargetDynamicAttributes('no-such-driver'),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->checkTargetDynamicAttributes('no-such-driver', { }),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->checkTargetDynamicAttributes('scst_local', { }), 0);
+    ok($SCST->checkTargetDynamicAttributes('iscsi', { }), 0);
+    ok($SCST->checkTargetDynamicAttributes('iscsi',
+					   { 'IncomingUser' => ''}), 0);
+    ok($SCST->checkTargetDynamicAttributes('iscsi',
+					   { 'IncomingUser' => '',
+					     'OutgoingUser' => '' }), 0);
+    ok($SCST->checkTargetDynamicAttributes('iscsi',
+					   { 'IncomingUser' => '',
+					     'OutgoingUser' => '',
+					     'NoSuchAttribute' => '' }), 1);
+
+    ok($SCST->addTargetDynamicAttribute(), $SCST->SCST_C_TGT_ADDATTR_FAIL);
+    ok($SCST->addTargetDynamicAttribute('no-such-driver', '', '', ''),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->addTargetDynamicAttribute('iscsi', 'no-such-target', '', ''),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->addTargetDynamicAttribute('iscsi', 'tgt1', 'no-such-attribute',
+					'', ''),
+       $SCST->SCST_C_TGT_BAD_ATTRIBUTES);
+    ok($SCST->addTargetDynamicAttribute('iscsi', 'tgt1', 'IncomingUser',
+					'bar 12CharSecret'), 0);
+    ok($SCST->addTargetDynamicAttribute('iscsi', 'tgt1', 'IncomingUser',
+					'joe 12charsecret'), 0);
+    my ($ta, $errorString) = $SCST->targetAttributes('iscsi', 'tgt1');
+    ok(Dumper($ta->{'IncomingUser'}),
+       Dumper({ 'keys' => { '0' => { 'value' => 'bar 12CharSecret' },
+	                    '1' => { 'value' => 'joe 12charsecret' } },
+	        'static' => 0 }));
+    ok($SCST->removeTargetDynamicAttribute(), $SCST->SCST_C_TGT_REMATTR_FAIL);
+    ok($SCST->removeTargetDynamicAttribute('no-such-driver', '', '', ''),
+       $SCST->SCST_C_DRV_NO_DRIVER);
+    ok($SCST->removeTargetDynamicAttribute('iscsi', 'no-such-target', '', ''),
+       $SCST->SCST_C_TGT_NO_TARGET);
+    ok($SCST->removeTargetDynamicAttribute('iscsi', 'tgt1', 'no-such-attribute',
+					   ''),
+       $SCST->SCST_C_TGT_BAD_ATTRIBUTES);
+    ok($SCST->removeTargetDynamicAttribute('iscsi', 'tgt1', 'IncomingUser',
+					   'joe 12charsecret'), 0);
+    ok($SCST->removeTargetDynamicAttribute('iscsi', 'tgt1', 'IncomingUser',
+					   'bar 12CharSecret'), 0);
+    ($ta, $errorString) = $SCST->targetAttributes('iscsi', 'tgt1');
+    ok(!exists($ta->{'IncomingUser'}));
+}
+
+sub teardown {
+    my $SCST = shift;
+
+    ok($SCST->removeVirtualTarget('iscsi', 'tgt1'), 0);
+    ok($SCST->closeDevice("vdisk_fileio", "disk01"), 0);
+}
+
+my $_DEBUG_ = 0;
+
+my $SCST = eval { new SCST::SCST($_DEBUG_) };
+die("Creation of SCST object failed") if (!defined($SCST));
+
+setup($SCST);
+testDriverDynAttr($SCST);
+testTargetDynAttr($SCST);
+teardown($SCST);
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/06-cont-on-err.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/06-cont-on-err.t
new file mode 100644
index 000000000..2aa100c6a
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/06-cont-on-err.t
@@ -0,0 +1,67 @@
+#!perl
+
+use strict;
+use Cwd qw(abs_path);
+use File::Basename;
+use File::Spec;
+use Test;
+
+my $testdir;
+my $scstadmin_pm_dir;
+my $scstadmin_dir;
+my $scstadmin;
+
+BEGIN {
+    $testdir = dirname(abs_path($0));
+    $scstadmin_pm_dir = dirname($testdir);
+    $scstadmin_dir = dirname($scstadmin_pm_dir);
+    $scstadmin = File::Spec->catfile($scstadmin_dir, "scstadmin");
+    unless(grep /blib/, @INC) {
+	unshift(@INC, File::Spec->catdir($scstadmin_pm_dir, "lib"));
+    }
+    plan tests => 2;
+}
+
+use Data::Dumper;
+use SCST::SCST;
+use File::Temp qw/tempfile/;
+
+sub setup {
+    my $SCST = shift;
+
+    my ($drivers, $errorString) = $SCST->drivers();
+    my %drivers = map { $_ => 1 } @{$drivers};
+    ok(exists($drivers{'ib_srpt'}));
+}
+
+sub testRestoreConfig {
+    my $to_be_restored = shift;
+    my $expected = shift;
+    my $tmpfilename1 = File::Spec->catfile(File::Spec->tmpdir(),
+					   "scstadmin-test-06-$$-1");
+    my $tmpfilename2 = File::Spec->catfile(File::Spec->tmpdir(),
+					   "scstadmin-test-06-$$-2");
+
+    system("$scstadmin -clear_config -force -noprompt -no_lip >/dev/null");
+    system("$scstadmin -cont_on_err -no_lip -config $to_be_restored" .
+	   " >/dev/null");
+    system("$scstadmin -write_config $tmpfilename1 >/dev/null");
+    system("awk 'BEGIN {t = 0 } /^TARGET_DRIVER.*{\$/ { if (\$0 != \"TARGET_DRIVER scst_local {\") t = 1 } /^}\$/ { if (t == 1) t = 2 } /^\$/ { if (t == 2) { t = 3 } } /^./ { if (t == 3) { t = 0 } } { if (t == 0) print }' <$tmpfilename1 >$tmpfilename2");
+    my $compare_result = system("diff -u $tmpfilename2 $expected");
+    ok($compare_result, 0);
+    if ($compare_result == 0) {
+	unlink($tmpfilename2);
+	unlink($tmpfilename1);
+    }
+}
+
+my $_DEBUG_ = 0;
+
+my $SCST = eval { new SCST::SCST($_DEBUG_) };
+die("Creation of SCST object failed") if (!defined($SCST));
+
+setup($SCST);
+
+testRestoreConfig(File::Spec->catfile($testdir, "to-be-restored.conf"),
+		  File::Spec->catfile($testdir, "after-restore.conf"));
+
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/99-stop-scst.t b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/99-stop-scst.t
new file mode 100644
index 000000000..6aeda35bd
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/99-stop-scst.t
@@ -0,0 +1,21 @@
+#!perl
+
+use strict;
+use Test;
+
+BEGIN {
+    plan tests => 2;
+}
+
+if ($> == 0) {
+    ok(system("killall iscsi-scstd; " .
+	      "modprobe -r scst_local; " .
+	      "modprobe -r iscsi-scst; " .
+	      "modprobe -r ib_srpt; " .
+	      "modprobe -r qla2x00tgt; " .
+	      "modprobe -r qla2xxx_scst; " .
+	      "modprobe -r scst_vdisk"), 0);
+    ok(!(-d "/sys/module/scst"));
+} else {
+    ok(1);
+}
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/after-restore.conf b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/after-restore.conf
new file mode 100644
index 000000000..9bcda73e5
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/after-restore.conf
@@ -0,0 +1,56 @@
+# Automatically generated by SCST Configurator v3.0.0-pre2.
+
+
+HANDLER vdisk_fileio {
+	DEVICE disk01 {
+		filename /proc/cpuinfo
+	}
+}
+
+TARGET_DRIVER scst_local {
+	TARGET local1 {
+		session_name local1_session
+
+		LUN 0 disk01
+		LUN 1 disk01
+
+		GROUP initator_group {
+			LUN 0 disk01
+			LUN 1 disk01 {
+				read_only 1
+			}
+			LUN 2 disk01
+
+			INITIATOR ini1
+
+			INITIATOR ini2
+
+			INITIATOR ini3
+		}
+	}
+}
+
+DEVICE_GROUP dg01 {
+	DEVICE disk01
+
+	TARGET_GROUP tg01a {
+		group_id 1
+		preferred 1
+		state active
+
+		TARGET tgt_a {
+			rel_tgt_id 2
+		}
+	}
+
+	TARGET_GROUP tg01b {
+		group_id 2
+		preferred 0
+		state active
+
+		TARGET tgt_b {
+			rel_tgt_id 3
+		}
+	}
+}
+
diff --git a/scstadmin/scstadmin.sysfs/scst-0.9.10/t/to-be-restored.conf b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/to-be-restored.conf
new file mode 100644
index 000000000..c5c3d6320
--- /dev/null
+++ b/scstadmin/scstadmin.sysfs/scst-0.9.10/t/to-be-restored.conf
@@ -0,0 +1,62 @@
+# Automatically generated by SCST Configurator v3.0.0-pre2.
+
+
+HANDLER vdisk_fileio {
+	DEVICE disk01 {
+		filename /proc/cpuinfo
+	}
+}
+
+TARGET_DRIVER ib_srpt {
+	TARGET no_such_target {
+		enabled 1
+	}
+}
+
+TARGET_DRIVER scst_local {
+	TARGET local1 {
+		session_name local1_session
+
+		LUN 0 disk01
+		LUN 1 disk01
+
+		GROUP initator_group {
+			LUN 0 disk01
+			LUN 1 disk01 {
+				read_only 1
+			}
+			LUN 2 disk01
+
+			INITIATOR ini1
+
+			INITIATOR ini2
+
+			INITIATOR ini3
+		}
+	}
+}
+
+DEVICE_GROUP dg01 {
+	DEVICE disk01
+
+	TARGET_GROUP tg01a {
+		group_id 1
+		preferred 1
+		state active
+
+		TARGET tgt_a {
+			rel_tgt_id 2
+		}
+	}
+
+	TARGET_GROUP tg01b {
+		group_id 2
+		preferred 0
+		state active
+
+		TARGET tgt_b {
+			rel_tgt_id 3
+		}
+	}
+}
+
diff --git a/scstadmin/scstadmin.sysfs/scstadmin b/scstadmin/scstadmin.sysfs/scstadmin
index 43ee1c160..07aa962a7 100755
--- a/scstadmin/scstadmin.sysfs/scstadmin
+++ b/scstadmin/scstadmin.sysfs/scstadmin
@@ -202,7 +202,7 @@ Target Driver Operations
      -issue_lip [<t>]
         [-driver <driver>]   : Issue a LIP for a specific driver/target or for
                                all drivers and targets.
-     -no_lip                 : Don't automatically issue a LIP after applying
+     -no_lip                 : Don\'t automatically issue a LIP after applying
                                configuration changes.
 
 Options
@@ -211,7 +211,8 @@ Options
      -force                  : Force all configuration changes,
                                even deletions (DANGER!).
      -noprompt               : Do not prompt or pause. Use with caution!
-  
+     -cont_on_err            : Continue after an error occurred.
+
 Debugging (limited support)
      -debug                  : Debug mode - don\'t do anything destructive.
 
@@ -258,6 +259,7 @@ my $CONFIG;
 my $CONFIGFILE;
 my $_DEBUG_;
 my $_NOPROMPT_;
+my $_CONT_ON_ERR_;
 
 my %CURRENT;
 
@@ -458,6 +460,7 @@ sub getArgs {
 
 			    'nonkey'		=> \$nonkey,
 			    'noprompt'		=> \$_NOPROMPT_,
+			    'cont_on_err'       => \$_CONT_ON_ERR_,
 			    'force'		=> \$force,
 			    'debug'             => \$_DEBUG_))
 	{
@@ -471,6 +474,7 @@ sub getArgs {
 
 	$_DEBUG_ = TRUE if (defined($_DEBUG_));
 	$_NOPROMPT_ = TRUE if (defined($_NOPROMPT_));
+	$_CONT_ON_ERR_ = TRUE if (defined($_CONT_ON_ERR_));
 
 	$force = TRUE if (defined($force));
 	$nonkey = TRUE if (defined($nonkey));
@@ -761,7 +765,7 @@ sub main {
 		defined($applyConfig) && do {
 			$CONFIGFILE = $applyConfig;
 			$rc = checkConfiguration();
-			immediateExit("Configuration has errors, aborting.") if ($rc);
+			condExit("Configuration has errors, aborting.") if ($rc);
 			last if ($force && prompt());
 			my $changes = applyConfiguration($force);
 			$rc = issueLip() if ($changes && !$noLip);
@@ -1166,58 +1170,58 @@ sub readWorkingConfig {
 
 	# Get current handlers/devices
 
-	my $handlers = $SCST->handlers();
-	immediateExit($SCST->errorString());
+	my ($handlers, $errorString) = $SCST->handlers();
+	immediateExit($errorString);
 
 	foreach my $handler (@{$handlers}) {
-		my $devices = $SCST->devicesByHandler($handler);
-		immediateExit($SCST->errorString());
+		my ($devices, $errorString) = $SCST->devicesByHandler($handler);
+		immediateExit($errorString);
 		$CURRENT{'handler'}->{$handler} = $devices;
 	}
 
 	# Get current assignments
 
-	my $drivers = $SCST->drivers();
-	immediateExit($SCST->errorString());
+	my ($drivers, $errorString) = $SCST->drivers();
+	immediateExit($errorString);
 
 	foreach my $driver (@{$drivers}) {
 		my %empty;
 		$CURRENT{'assign'}->{$driver} = \%empty;
-		my $targets = $SCST->targets($driver);
-		immediateExit($SCST->errorString());
+		my ($targets, $errorString) = $SCST->targets($driver);
+		immediateExit($errorString);
 		foreach my $target (@{$targets}) {
 			my %empty;
 			$CURRENT{'assign'}->{$driver}->{$target} = \%empty;
 
-			my $luns = $SCST->luns($driver, $target);
+			my ($luns, $errorString) = $SCST->luns($driver, $target);
 
 			$CURRENT{'assign'}->{$driver}->{$target}->{'LUN'} = $luns if (defined($luns));
 
-			my $groups = $SCST->groups($driver, $target);
-			immediateExit($SCST->errorString());
+			my ($groups, $errorString) = $SCST->groups($driver, $target);
+			immediateExit($errorString);
 			foreach my $group (@{$groups}) {
-				$CURRENT{'assign'}->{$driver}->{$target}->{'GROUP'}->{$group}->{'INITIATORS'} =
-				  $SCST->initiators($driver, $target, $group);
-				immediateExit($SCST->errorString());
-
-				$CURRENT{'assign'}->{$driver}->{$target}->{'GROUP'}->{$group}->{'LUN'} =
-				  $SCST->luns($driver, $target, $group);
-				immediateExit($SCST->errorString());
+				my ($initiators, $errorString) = $SCST->initiators($driver, $target, $group);
+				immediateExit($errorString);
+				$CURRENT{'assign'}->{$driver}->{$target}->{'GROUP'}->{$group}->{'INITIATORS'} = $initiators;
+				my ($luns, $errorString) = $SCST->luns($driver, $target, $group);
+				$CURRENT{'assign'}->{$driver}->{$target}->{'GROUP'}->{$group}->{'LUN'} = $luns;
+				immediateExit($errorString);
 			}
 		}
 	}
 
-	my $dgroups = $SCST->deviceGroups();
-	immediateExit($SCST->errorString());
+	my ($dgroups, $errorString) = $SCST->deviceGroups();
+	immediateExit($errorString);
 
 	foreach my $dgroup (@{$dgroups}) {
-		$CURRENT{'dgroups'}->{$dgroup}->{'devices'} = $SCST->deviceGroupDevices($dgroup);
-		immediateExit($SCST->errorString());			
-		my $tgroups = $SCST->targetGroups($dgroup);
-		immediateExit($SCST->errorString());
+		my ($dgd, $errorString) = $SCST->deviceGroupDevices($dgroup);
+		immediateExit($errorString);			
+		$CURRENT{'dgroups'}->{$dgroup}->{'devices'} = $dgd;
+		my ($tgroups, $errorString) = $SCST->targetGroups($dgroup);
+		immediateExit($errorString);
 		foreach my $tgroup (@{$tgroups}) {
-			$CURRENT{'dgroups'}->{$dgroup}->{'tgroups'}->{$tgroup}->{'targets'} =
-			  $SCST->targetGroupTargets($dgroup, $tgroup);
+			my ($tgt, $errorString) = $SCST->targetGroupTargets($dgroup, $tgroup);
+			$CURRENT{'dgroups'}->{$dgroup}->{'tgroups'}->{$tgroup}->{'targets'} = $tgt;
 		}
 	}
 
@@ -1281,12 +1285,14 @@ sub serializeKeyAttr {
 		   && defined($$attr_filter{$attribute})));
 
 	if (defined($$attributes{$attribute}->{'keys'})) {
-	    foreach my $key (sort keys %{$$attributes{$attribute}->{'keys'}}) {
+	    my @values;
+	    foreach my $key (keys %{$$attributes{$attribute}->{'keys'}}) {
 		my $value =
 		    $$attributes{$attribute}->{'keys'}->{$key}->{'value'};
-		if ($value ne '') {
-		    $result .= "$prefix$attribute " . escapeMeta($value) . "\n";
-		}
+		push (@values, $value) if ($value ne '');
+	    }
+	    foreach my $value (sort @values) {
+		$result .= "$prefix$attribute " . escapeMeta($value) . "\n";
 	    }
 	} elsif ($attribute eq 'enabled' || $attribute eq 'hw_target') {
 	    my $value = $$attributes{$attribute}->{'value'};
@@ -1342,8 +1348,8 @@ sub writeConfiguration {
 	print $io "# Automatically generated by $Version.\n\n";
 
 	{
-		my $attributes = $SCST->scstAttributes();
-		immediateExit($SCST->errorString());
+		my ($attributes, $errorString) = $SCST->scstAttributes();
+		immediateExit($errorString);
 
 		print $io serializeKeyAttr("", $attributes);
 		if ($nonkey) {
@@ -1360,8 +1366,8 @@ sub writeConfiguration {
 		my $handler_buff;
 		my $handler_buff_nk;
 
-		my $handler_attrs = $SCST->deviceCreateAttributes($handler);
-		my $attributes = $SCST->handlerAttributes($handler);
+		my ($handler_attrs, $errorString) = $SCST->deviceCreateAttributes($handler);
+		my ($attributes, $errorString) = $SCST->handlerAttributes($handler);
 
 		$handler_buff = serializeKeyAttr("\t", $attributes);
 		$handler_buff_nk = serializeNkAttr("\t", $attributes) if ($nonkey);
@@ -1372,7 +1378,7 @@ sub writeConfiguration {
 		foreach my $device (sort @{$devices}) {
 			$device_buff .= "\tDEVICE $device";
 
-			my $attributes = $SCST->deviceAttributes($device);
+			my ($attributes, $errorString) = $SCST->deviceAttributes($device);
 
 			my $attribute_buff;
 			my $attribute_buff_nk;
@@ -1417,7 +1423,7 @@ sub writeConfiguration {
 	foreach my $driver (sort keys %{$CURRENT{'assign'}}) {
 		my $driver_buff;
 
-		my $drv_attrs = $SCST->driverAttributes($driver);
+		my ($drv_attrs, $errorString) = $SCST->driverAttributes($driver);
 
 		my $drv_attr_buff;
 		my $drv_attr_buff_nk;
@@ -1428,13 +1434,13 @@ sub writeConfiguration {
 		$drv_attr_buff_nk .= "\n" if ($drv_attr_buff_nk);
 
 		my $targets = $CURRENT{'assign'}->{$driver};
-		my $tgt_attrs = $SCST->targetCreateAttributes($driver);
+		my ($tgt_attrs, $errorString) = $SCST->targetCreateAttributes($driver);
 
 		my $target_buff;
 		foreach my $target (sort keys %{$targets}) {
 			$target_buff .= "\tTARGET $target";
 
-			my $attributes = $SCST->targetAttributes($driver, $target);
+			my ($attributes, $errorString) = $SCST->targetAttributes($driver, $target);
 
 			my $attribute_buff;
 			my $attribute_buff_nk;
@@ -1450,7 +1456,7 @@ sub writeConfiguration {
 			$attribute_buff_nk .= "\n" if ($attribute_buff_nk);
 
 			my $luns = $CURRENT{'assign'}->{$driver}->{$target}->{'LUN'};
-			my $lun_attrs = $SCST->lunCreateAttributes($driver, $target);
+			my ($lun_attrs, $errorString) = $SCST->lunCreateAttributes($driver, $target);
 
 			my $t_lun_buff;
 			foreach my $lun (sort numerically keys %{$luns}) {
@@ -1458,7 +1464,7 @@ sub writeConfiguration {
 
 				$t_lun_buff .= "\t\tLUN $lun $lun_dev";
 
-				my $attributes = $SCST->lunAttributes($driver, $target, $lun);
+				my ($attributes, $errorString) = $SCST->lunAttributes($driver, $target, $lun);
 				my $l_attribute_buff =
 				    serializeKeyAttr("\t\t\t",
 						     $attributes,
@@ -1489,8 +1495,8 @@ sub writeConfiguration {
 
 			my $group_buff;
 			foreach my $group (sort keys %{$groups}) {
-				my $lun_attrs = $SCST->lunCreateAttributes($driver, $target, $group);
-				my $ini_attrs = $SCST->initiatorCreateAttributes($driver, $target, $group);
+				my ($lun_attrs, $errorString) = $SCST->lunCreateAttributes($driver, $target, $group);
+				my ($ini_attrs, $errorString) = $SCST->initiatorCreateAttributes($driver, $target, $group);
 
 				$group_buff .= "\t\tGROUP $group";
 
@@ -1502,7 +1508,7 @@ sub writeConfiguration {
 
 					$lun_buff .= "\t\t\tLUN $lun $lun_dev";
 
-					my $attributes = $SCST->lunAttributes($driver, $target, $lun, $group);
+					my ($attributes, $errorString) = $SCST->lunAttributes($driver, $target, $lun, $group);
 
 					my $l_attribute_buff
 					    = serializeKeyAttr("\t\t\t\t",
@@ -1532,9 +1538,9 @@ sub writeConfiguration {
 
 				my $init_buff;
 				foreach my $init (sort @{$inits}) {
-					$init_buff .= "\n\t\t\tINITIATOR $init";
+					$init_buff .= "\n\t\t\tINITIATOR " . escapeMeta($init);
 
-					my $attributes = $SCST->initiatorAttributes($driver, $target, $group, $init);
+					my ($attributes, $errorString) = $SCST->initiatorAttributes($driver, $target, $group, $init);
 
 					my $i_attribute_buff
 					    = serializeKeyAttr("\t\t\t\t",
@@ -1566,7 +1572,7 @@ sub writeConfiguration {
 					$group_buff .= $init_buff;
 				}
 
-				my $grp_attributes = $SCST->groupAttributes($driver, $target, $group);
+				my ($grp_attributes, $errorString) = $SCST->groupAttributes($driver, $target, $group);
 				my $g_attribute_buff
 				    = serializeKeyAttr("\t\t\t",
 						       $grp_attributes);
@@ -1630,10 +1636,23 @@ sub writeConfiguration {
 		}
 	}
 
+	my ($dga, $errorString) = $SCST->aluaAttributes();
+	my $dga_buff = serializeKeyAttr("\t", $dga);
+	my $dga_buff_nk = serializeNkAttr("\t", $dga) if ($nonkey);
+	if ($dga_buff_nk) {
+		$dga_buff .= "\t# Non-key attributes\n";
+		$dga_buff .= $dga_buff_nk;
+	}
+	if ($dga_buff) {
+		print $io "ALUA {\n";
+		print $io $dga_buff;
+		print $io "}\n\n";
+	}
+
 	foreach my $dgroup (sort keys %{$CURRENT{'dgroups'}}) {
 		my $dgroup_buff;
 
-		my $dgroup_attrs = $SCST->deviceGroupAttributes($dgroup);
+		my ($dgroup_attrs, $errorString) = $SCST->deviceGroupAttributes($dgroup);
 
 		my $dgrp_attr_buff;
 		my $dgrp_attr_buff_nk;
@@ -1660,7 +1679,7 @@ sub writeConfiguration {
 		foreach my $tgroup (sort keys %{$tgroups}) {
 			$tgroup_buff .= "\tTARGET_GROUP $tgroup";
 
-			my $attributes = $SCST->targetGroupAttributes($dgroup, $tgroup);
+			my ($attributes, $errorString) = $SCST->targetGroupAttributes($dgroup, $tgroup);
 
 			my $attribute_buff;
 			my $attribute_buff_nk;
@@ -1676,7 +1695,7 @@ sub writeConfiguration {
 			foreach my $tgt (@{$tgts}) {
 				$tgt_buff .= "\t\tTARGET $tgt";
 
-				my $tgt_attrs = $SCST->targetGroupTargetAttributes($dgroup, $tgroup, $tgt);
+				my ($tgt_attrs, $errorString) = $SCST->targetGroupTargetAttributes($dgroup, $tgroup, $tgt);
 
 				my $t_attribute_buff
 				  = serializeKeyAttr("\t\t\t", $tgt_attrs);
@@ -1940,13 +1959,17 @@ sub applyConfiguration {
 	# Apply config additions
 	$changes += applyConfigDevices($CONFIG, $force);
 	$changes += applyConfigAssignments($CONFIG, $force);
+	$changes += applyConfigAlua($CONFIG, $force);
 	$changes += applyConfigDeviceGroups($CONFIG, $force);
+	$changes += applyConfigEnableTargets($CONFIG, $force);
+	$changes += applyConfigEnableDrivers($CONFIG, $force);
 
 	# And SCST attributes..
 	my %_attributes;
 	foreach my $item (keys %{$CONFIG}) {
 		next if ($item eq 'HANDLER');
 		next if ($item eq 'TARGET_DRIVER');
+		next if ($item eq 'ALUA');
 		next if ($item eq 'DEVICE_GROUP');
 		$_attributes{$item} = $$CONFIG{$item};
 	}
@@ -1970,7 +1993,7 @@ sub applyConfigDevices {
 	foreach my $handler (keys %{$handlers}) {
 		foreach my $device (@{$$handlers{$handler}}) {
 			if (!defined($$config{'HANDLER'}->{$handler}->{'DEVICE'}->{$device})) {
-				my $attributes = $SCST->deviceAttributes($device);
+				my ($attributes, $errorString) = $SCST->deviceAttributes($device);
 
 				if ($deletions) {
 					closeDevice($handler, $device, $deletions);
@@ -1997,14 +2020,14 @@ sub applyConfigDevices {
 
 				my $attributes = configToAttr(\%_attributes);
 				my $create_attrs = configToAttr(\%_attributes);
-				my $possible = $SCST->deviceCreateAttributes($handler);
-				immediateExit($SCST->errorString());
+				my ($possible, $errorString) = $SCST->deviceCreateAttributes($handler);
+				condExit($errorString);
 				filterCreateAttributes($possible, $create_attrs, FALSE);
 				filterCreateAttributes($possible, $attributes, TRUE);
 
 				if (handlerHasDevice($handler, $device)) {
-					my $old_create_attrs = $SCST->deviceAttributes($device);
-					immediateExit($SCST->errorString());
+					my ($old_create_attrs, $errorString) = $SCST->deviceAttributes($device);
+					condExit($errorString);
 					filterCreateAttributes($possible, $old_create_attrs, FALSE);
 
 					if (compareToKeyAttribute($create_attrs, $old_create_attrs)) {
@@ -2083,10 +2106,10 @@ sub applyConfigAssignments {
 					}
 				} else {
 					my $c_attrs = configToAttr($$config{'TARGET_DRIVER'}->{$driver}->{'TARGET'}->{$target}->{'LUN'}->{$lun}->{$device});
-					my $o_attrs = $SCST->lunAttributes($driver, $target, $lun);
-					immediateExit($SCST->errorString());
-					my $possible = $SCST->lunCreateAttributes($driver, $target);
-					immediateExit($SCST->errorString());
+					my ($o_attrs, $errorString) = $SCST->lunAttributes($driver, $target, $lun);
+					condExit($errorString);
+					my ($possible, $errorString) = $SCST->lunCreateAttributes($driver, $target);
+					condExit($errorString);
 
 					filterCreateAttributes($possible, $c_attrs, FALSE);
 
@@ -2126,10 +2149,10 @@ sub applyConfigAssignments {
 						}
 					} else {
 						my $c_attrs = configToAttr($$config{'TARGET_DRIVER'}->{$driver}->{'TARGET'}->{$target}->{'GROUP'}->{$group}->{'LUN'}->{$lun}->{$device});
-						my $o_attrs = $SCST->lunAttributes($driver, $target, $lun, $group);
-						immediateExit($SCST->errorString());
-						my $possible = $SCST->lunCreateAttributes($driver, $target, $group);
-						immediateExit($SCST->errorString());
+						my ($o_attrs, $errorString) = $SCST->lunAttributes($driver, $target, $lun, $group);
+						condExit($errorString);
+						my ($possible, $errorString) = $SCST->lunCreateAttributes($driver, $target, $group);
+						condExit($errorString);
 
 						filterCreateAttributes($possible, $c_attrs, FALSE);
 
@@ -2170,21 +2193,17 @@ sub applyConfigAssignments {
 
 	foreach my $driver (sort keys %{$assignments}) {
 		if (!defined($CURRENT{'assign'}->{$driver})) {
-			immediateExit("Target driver '$driver' is not loaded or available.");
+			condExit("Target driver '$driver' is not loaded or available.");
 		}
 
 		my %_attributes;
-		my %special;
 		foreach my $item (keys %{$$assignments{$driver}}) {
 			if ($item eq 'TARGET') {
 				$changes += applyTargetAssignments($driver, $$assignments{$driver}->{$item},
 				  $deletions);
 			} elsif ($item ne 'enabled') {
-				# Enable driver last
+				# Enabling a driver happens in applyConfigEnableDrivers()
 				$_attributes{$item} = $$assignments{$driver}->{$item};
-			} else {
-				$special{$item} = $$assignments{$driver}->{$item};
-
 			}
 		}
 
@@ -2193,9 +2212,28 @@ sub applyConfigAssignments {
 		if (scalar keys %{$attributes}) {
 			$changes += setDriverAttributes($driver, $attributes, $deletions);
 		}
+	}
 
-		$attributes = configToAttr(\%special);
-		my $d_attributes = $SCST->driverAttributes($driver);
+	return $changes;
+}
+
+sub applyConfigEnableDrivers {
+	my $config = shift;
+	my $deletions = shift;
+	my $changes = 0;
+
+	my $assignments = $$config{'TARGET_DRIVER'};
+
+	foreach my $driver (sort keys %{$assignments}) {
+		my %_attributes;
+		foreach my $item (keys %{$$assignments{$driver}}) {
+			if ($item eq 'enabled') {
+				$_attributes{$item} = $$assignments{$driver}->{$item};
+			}
+		}
+
+		my $attributes = configToAttr(\%_attributes);
+		my ($d_attributes, $errorString) = $SCST->driverAttributes($driver);
 
 		if (defined($$d_attributes{'enabled'}) &&
 		    ($$d_attributes{'enabled'}->{'value'} != $$attributes{'enabled'})) {
@@ -2207,6 +2245,19 @@ sub applyConfigAssignments {
 	return $changes;
 }
 
+sub applyConfigAlua {
+	my $config = shift;
+	my $deletions = shift;
+
+	my $alua_attr = $$config{'ALUA'};
+	my %_attributes;
+	foreach my $item (keys %{$alua_attr}) {
+		$_attributes{$item} = $alua_attr->{$item};
+	}
+	my $attributes = configToAttr(\%_attributes);
+	return setAluaAttributes($attributes);
+}
+
 sub applyConfigDeviceGroups {
 	my $config = shift;
 	my $deletions = shift;
@@ -2412,7 +2463,7 @@ sub applyTargetAssignments {
 
 			if ($deletions && $isVirtual) {
 				my $rc = removeVirtualTarget($driver, $target);
-				immediateExit($SCST->errorString($rc)) if ($rc);
+				condExit($SCST->errorString($rc));
 				$changes++;
 			} else {
 				print "\t-> Virtual target '$target' for driver '$driver' is not in configuration. ".
@@ -2423,16 +2474,16 @@ sub applyTargetAssignments {
 
 	my $possible;
 
-	my $is_virtual = $SCST->driverIsVirtualCapable($driver);
+	my ($is_virtual, $errorString) = $SCST->driverIsVirtualCapable($driver);
 
 	if ($is_virtual) {
-		$possible = $SCST->targetCreateAttributes($driver);
+		($possible, $errorString) = $SCST->targetCreateAttributes($driver);
 	}
 
 	foreach my $target (sort keys %{$targets}) {
 		if (!defined($CURRENT{'assign'}->{$driver}->{$target})) {
 			if (!$is_virtual) {
-				immediateExit("Target '$target' for driver '$driver' does not exist.");
+				condExit("Target '$target' for driver '$driver' does not exist.");
 			} else {
 				my %_attributes;
 
@@ -2445,13 +2496,13 @@ sub applyTargetAssignments {
 				my $attributes = configToAttr(\%_attributes);
 
 				if (defined($$attributes{'HW_TARGET'})) {
-					immediateExit("Hardware target '$target' for driver '$driver' does not exist.");
+					condExit("Hardware target '$target' for driver '$driver' does not exist.");
 				}					
 
 				filterCreateAttributes($possible, $attributes, FALSE);
 
 				my $rc = addVirtualTarget($driver, $target, $attributes);
-				immediateExit($SCST->errorString($rc)) if ($rc);
+				condExit($SCST->errorString($rc));
 				$changes++ if (!$rc);
 			}
 		}
@@ -2465,28 +2516,52 @@ sub applyTargetAssignments {
 		}
 
 		my $attributes = configToAttr(\%_attributes);
-		filterCreateAttributes($possible, $attributes, TRUE);
+		if ($SCST->targetType($driver, $target) == $SCST::SCST::TGT_TYPE_VIRTUAL) {
+			filterCreateAttributes($possible, $attributes, TRUE);
+		}
 		$changes += setTargetAttributes($driver, $target, $attributes, $deletions);
 
-		%_attributes = ();
 		foreach my $item (keys %{$$targets{$target}}) {
 			if ($item eq 'GROUP') {
 				$changes += applyGroupAssignments($driver, $target, $$targets{$target}->{$item});
 				$changes += applyInitiatorAssignments($driver, $target, $$targets{$target}->{$item}, $deletions);
 			} elsif ($item eq 'LUN') {
 				$changes += applyLunAssignments($driver, $target, undef, $$targets{$target}->{$item});
-			} elsif ($item eq 'enabled') {
-				$_attributes{$item} = $$targets{$target}->{$item};
 			}
 		}
+	}
 
-		$attributes = configToAttr(\%_attributes);
-		my $t_attributes = $SCST->targetAttributes($driver, $target);
+	return $changes;
+}
 
-		if (defined($$t_attributes{'enabled'}) &&
-		    ($$t_attributes{'enabled'}->{'value'} != $$attributes{'enabled'})) {
-			setTargetAttribute($driver, $target, 'enabled', $$attributes{'enabled'});
-			$changes++;
+sub applyConfigEnableTargets {
+	my $config = shift;
+	my $deletions = shift;
+	my $changes = 0;
+
+	my $assignments = $$config{'TARGET_DRIVER'};
+
+	foreach my $driver (sort keys %{$assignments}) {
+		foreach my $driver_item (keys %{$$assignments{$driver}}) {
+			next if ($driver_item ne 'TARGET');
+			my $targets = $$assignments{$driver}->{$driver_item};
+			foreach my $target (sort keys %{$targets}) {
+				my %_attributes = ();
+				foreach my $target_item (keys %{$$targets{$target}}) {
+					if ($target_item eq 'enabled') {
+						$_attributes{$target_item} = $$targets{$target}->{$target_item};
+					}
+				}
+
+				my $attributes = configToAttr(\%_attributes);
+				my ($t_attributes, $errorString) = $SCST->targetAttributes($driver, $target);
+
+				if (defined($$t_attributes{'enabled'}) &&
+				    ($$t_attributes{'enabled'}->{'value'} != $$attributes{'enabled'})) {
+					setTargetAttribute($driver, $target, 'enabled', $$attributes{'enabled'});
+					$changes++;
+				}
+			}
 		}
 	}
 
@@ -2638,17 +2713,17 @@ sub clearConfiguration {
 
 	foreach my $handler (sort keys %{$handlers}) {
 		foreach my $device (@{$$handlers{$handler}}) {
-			my $attributes = $SCST->deviceAttributes($device);
+			my ($attributes, $errorString) = $SCST->deviceAttributes($device);
 			closeDevice($handler, $device, TRUE);
 		}
 	}
 
 	# Todo - check return code
 
-	my $drivers = $SCST->drivers();
+	my ($drivers, $errorString) = $SCST->drivers();
 
 	foreach my $driver (@{$drivers}) {
-		my $targets = $SCST->targets($driver);
+		my ($targets, $errorString) = $SCST->targets($driver);
 
 		foreach my $target (@{$targets}) {
 			disableTarget($driver, $target);
@@ -2668,10 +2743,10 @@ sub addVirtualTarget {
 	my $attributes = shift;
 
 	# Enable all hardware targets before creating virtual ones
-	my $targets = $SCST->targets($driver);
+	my ($targets, $errorString) = $SCST->targets($driver);
 
 	foreach my $_target (@{$targets}) {
-		my $attributes = $SCST->targetAttributes($driver, $_target);
+		my ($attributes, $errorString) = $SCST->targetAttributes($driver, $_target);
 
 		if (defined($$attributes{'hw_target'}) &&
 		    !$$attributes{'enabled'}->{'value'}) {
@@ -2704,7 +2779,7 @@ sub listHandlers {
 
 	return listHandler($handler) if ($handler);
 
-	my $handlers = $SCST->handlers();
+	my ($handlers, $errorString) = $SCST->handlers();
 
 	my $l_handler;
 	foreach my $handler (@{$handlers}) {
@@ -2730,7 +2805,7 @@ sub listHandler {
 	my %toprint;
 
 	my $got_handler = ($handler ne '');
-	my $handlers = $SCST->handlers();
+	my ($handlers, $errorString) = $SCST->handlers();
 
 	my $l_device;
 	my $l_handler;
@@ -2743,7 +2818,7 @@ sub listHandler {
 
 			$l_handler = length($handler) if ($l_handler < length($handler));
 
-			my $devices = $SCST->devicesByHandler($handler);
+			my ($devices, $errorString) = $SCST->devicesByHandler($handler);
 
 			if ($#{$devices} == -1) {
 				push @{$devices}, '-';
@@ -2764,7 +2839,7 @@ sub listHandler {
 		print "\n";
 
 		foreach my $handler (keys %toprint) {
-			my $devices = $SCST->devicesByHandler($handler);
+			my ($devices, $errorString) = $SCST->devicesByHandler($handler);
 			my $first = TRUE;
 
 			if ($#{$devices} == -1) {
@@ -2799,9 +2874,9 @@ sub listDevice {
 	my $device = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->deviceAttributes($device);
+	my ($attributes, $errorString) = $SCST->deviceAttributes($device);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such device '$device' exists.\n";
@@ -2817,7 +2892,7 @@ sub listDeviceGroups {
 
 	return listDeviceGroup($group) if ($group ne '');
 
-	my $groups = $SCST->deviceGroups();
+	my ($groups, $errorString) = $SCST->deviceGroups();
 
 	my $l_group;
 	foreach my $group (@{$groups}) {
@@ -2844,7 +2919,7 @@ sub listDeviceGroups {
 sub listDeviceGroup {
 	my $group = shift;
 
-	my $devices = $SCST->deviceGroupDevices($group);
+	my ($devices, $errorString) = $SCST->deviceGroupDevices($group);
 
 	my $l_device;
 	foreach my $device (@{$devices}) {
@@ -2864,7 +2939,7 @@ sub listDeviceGroup {
 		print "\t$device\n";
 	}
 
-	my $tgroups = $SCST->targetGroups($group);
+	my ($tgroups, $errorString) = $SCST->targetGroups($group);
 
 	my $l_tgroup;
 	foreach my $tgroup (@{$tgroups}) {
@@ -2895,7 +2970,7 @@ sub listTargetGroups {
 	return listDeviceGroups(undef, TRUE) if ($group eq '');
 	return listTargetGroup($group, $tgroup) if ($tgroup ne '');
 
-	my $tgroups = $SCST->targetGroups($group);
+	my ($tgroups, $errorString) = $SCST->targetGroups($group);
 
 	my $l_tgroup;
 	foreach my $tgroup (@{$tgroups}) {
@@ -2926,7 +3001,7 @@ sub listTargetGroup {
 	my $group = shift;
 	my $tgroup = shift;
 
-	my $targets = $SCST->targetGroupTargets($group, $tgroup);
+	my ($targets, $errorString) = $SCST->targetGroupTargets($group, $tgroup);
 
 	my $l_tgt;
 	foreach my $tgt (@{$targets}) {
@@ -2955,7 +3030,7 @@ sub listDeviceGroupDevices {
 
 	return listDevice($device) if ($device ne '');
 
-	my $devices = $SCST->deviceGroupDevices($group);
+	my ($devices, $errorString) = $SCST->deviceGroupDevices($group);
 
 	my $l_device;
 	foreach my $device (@{$devices}) {
@@ -2983,7 +3058,7 @@ sub listDrivers {
 
 	return listTargets($driver, undef) if ($driver ne '');
 
-	my $drivers = $SCST->drivers();
+	my ($drivers, $errorString) = $SCST->drivers();
 
 	my $l_driver;
 	foreach my $driver (@{$drivers}) {
@@ -3013,7 +3088,7 @@ sub listTargets {
 
 	my $got_driver = ($driver ne '');
 
-	my $drivers = $SCST->drivers();
+	my ($drivers, $errorString) = $SCST->drivers();
 
 	my $l_driver;
 	my $l_target;
@@ -3026,7 +3101,7 @@ sub listTargets {
 
 			$l_driver = length($driver) if ($l_driver < length($driver));
 
-			my $targets = $SCST->targets($driver);
+			my ($targets, $errorString) = $SCST->targets($driver);
 
 			foreach my $target (@{$targets}) {
 				$l_target = length($target) if ($l_target < length($target));
@@ -3045,7 +3120,7 @@ sub listTargets {
 		my %p;
 
 		foreach my $driver (keys %toprint) {
-			my $targets = $SCST->targets($driver);
+			my ($targets, $errorString) = $SCST->targets($driver);
 
 			foreach my $target (@{$targets}) {
 				if (!defined($p{$driver})) {
@@ -3064,17 +3139,17 @@ sub listTargets {
 }
 
 sub listSessions {
-	my $drivers = $SCST->drivers();
+	my ($drivers, $errorString) = $SCST->drivers();
 
 	foreach my $driver (@{$drivers}) {
-		my $targets = $SCST->targets($driver);
+		my ($targets, $errorString) = $SCST->targets($driver);
 
 		foreach my $target (@{$targets}) {
 			my $had_sessions = FALSE;
 
 			print "Driver/Target: $driver/$target\n\n";
 
-			my $sessions = $SCST->sessions($driver, $target);
+			my ($sessions, $errorString) = $SCST->sessions($driver, $target);
 			foreach my $session (keys %{$sessions}) {
 				print "\tSession: $session\n\n";
 
@@ -3112,12 +3187,13 @@ sub listGroup {
 	my $group = shift;
 	my $luns = shift;
 	my $initiators = shift;
+	my $errorString;
 
-	$luns = $SCST->luns($driver, $target, $group) if (!$luns);
-	$initiators = $SCST->initiators($driver, $target, $group)
-	  if (($initiators eq '') && ($group ne ''));
-
-	return TRUE if issueWarning($SCST->errorString());
+	($luns, $errorString) = $SCST->luns($driver, $target, $group) if (!$luns);
+	if (($initiators eq '') && ($group ne '')) {
+		($initiators, $errorString) = $SCST->initiators($driver, $target, $group);
+		return TRUE if issueWarning($errorString);
+	}
 
 	if ((keys %{$luns}) || ($#{$initiators} > -1)) {
 		my $l_device;
@@ -3193,13 +3269,13 @@ sub listGroups {
 	my $got_target = $target;
 	my $got_driver = $driver;
 
-	my $drivers = $SCST->drivers();
+	my ($drivers, $errorString) = $SCST->drivers();
 
 	foreach my $_driver (@{$drivers}) {
 		$driver = $_driver if (!$got_driver);
 
 		if ($driver eq $_driver) {
-			my $targets = $SCST->targets($driver);
+			my ($targets, $errorString) = $SCST->targets($driver);
 			foreach my $_target (@{$targets}) {
 				$target = $_target if (!$got_target);
 
@@ -3212,7 +3288,7 @@ sub listGroups {
 
 					print "\n";
 
-					my $groups = $SCST->groups($driver, $target);
+					my ($groups, $errorString) = $SCST->groups($driver, $target);
 					foreach my $_group (@{$groups}) {
 						$group = $_group if (!$got_group);
 
@@ -3245,10 +3321,12 @@ sub listGroups {
 sub listExported {
 	my $device = shift;
 	my $attributes = shift;
+	my $errorString;
 
-	$attributes = $SCST->deviceAttributes($device) if (!$attributes);
-
-	return TRUE if issueWarning($SCST->errorString());
+	if (!$attributes) {
+		($attributes, $errorString) = $SCST->deviceAttributes($device) ;
+		return TRUE if issueWarning($errorString);
+	}
 
 	if (keys %{$$attributes{'exported'}}) {
 		my $exported = $$attributes{'exported'}->{'value'};
@@ -3416,9 +3494,9 @@ sub listAttributes {
 sub listScstAttributes {
 	my $nonkey = shift;
 
-	my $attributes = $SCST->scstAttributes();
+	my ($attributes, $errorString) = $SCST->scstAttributes();
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "FATAL: Unable to get a list of SCST attributes! Please make sure SCST is loaded.\n";
@@ -3432,9 +3510,9 @@ sub listHandlerAttributes {
 	my $handler = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->handlerAttributes($handler);
+	my ($attributes, $errorString) = $SCST->handlerAttributes($handler);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such handler '$handler' found.\n";
@@ -3444,9 +3522,9 @@ sub listHandlerAttributes {
 	my $rc = listAttributes($attributes, $nonkey);
 	return $rc if $rc;
 
-	$attributes = $SCST->deviceCreateAttributes($handler);
+	($attributes, $errorString) = $SCST->deviceCreateAttributes($handler);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 	return TRUE if (!scalar keys %{$attributes});
 
 	print "\n\tDevice CREATE attributes available\n";
@@ -3463,16 +3541,16 @@ sub listDriverAttributes {
 	my $driver = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->driverAttributes($driver);
+	my ($attributes, $errorString) = $SCST->driverAttributes($driver);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	my $rc = listAttributes($attributes, $nonkey);
 	return $rc if ($rc);
 
 	if ($SCST->driverIsVirtualCapable($driver)) {
-		$attributes = $SCST->driverDynamicAttributes($driver);
-		return TRUE if issueWarning($SCST->errorString());
+		($attributes, $errorString) = $SCST->driverDynamicAttributes($driver);
+		return TRUE if issueWarning($errorString);
 
 		if (scalar keys %{$attributes}) {
 			print "\n\tDynamic attributes available\n";
@@ -3483,9 +3561,9 @@ sub listDriverAttributes {
 			}
 		}
 
-		my $attributes = $SCST->targetCreateAttributes($driver);
+		my ($attributes, $errorString) = $SCST->targetCreateAttributes($driver);
 
-		return TRUE if issueWarning($SCST->errorString());
+		return TRUE if issueWarning($errorString);
 		return TRUE if (!scalar keys %{$attributes});
 
 		print "\n\tTarget CREATE attributes available:\n";
@@ -3504,9 +3582,9 @@ sub listTargetAttributes {
 	my $target = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->targetAttributes($driver, $target);
+	my ($attributes, $errorString) = $SCST->targetAttributes($driver, $target);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such driver/target '$driver/$target' found.\n";
@@ -3517,8 +3595,8 @@ sub listTargetAttributes {
 	return $rc if $rc;
 
 	if ($SCST->driverIsVirtualCapable($driver)) {
-		$attributes = $SCST->targetDynamicAttributes($driver);
-		return TRUE if issueWarning($SCST->errorString());
+		($attributes, $errorString) = $SCST->targetDynamicAttributes($driver);
+		return TRUE if issueWarning($errorString);
 
 		if (scalar keys %{$attributes}) {
 			print "\n\tDynamic attributes available\n";
@@ -3530,9 +3608,9 @@ sub listTargetAttributes {
 		}
 	}
 
-	$attributes = $SCST->lunCreateAttributes($driver, $target);
+	($attributes, $errorString) = $SCST->lunCreateAttributes($driver, $target);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 	return TRUE if (!scalar keys %{$attributes});
 
 	print "\n\tLUN CREATE attributes available\n";
@@ -3551,9 +3629,9 @@ sub listGroupAttributes {
 	my $group = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->groupAttributes($driver, $target, $group);
+	my ($attributes, $errorString) = $SCST->groupAttributes($driver, $target, $group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such driver/target/group '$driver/$target/$group' found.\n";
@@ -3563,9 +3641,9 @@ sub listGroupAttributes {
 	my $rc = listAttributes($attributes, $nonkey);
 	return $rc if $rc;
 
-	$attributes = $SCST->lunCreateAttributes($driver, $target, $group);
+	($attributes, $errorString) = $SCST->lunCreateAttributes($driver, $target, $group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 	return TRUE if (!scalar keys %{$attributes});
 
 	print "\n\tLUN CREATE attributes available\n";
@@ -3575,9 +3653,9 @@ sub listGroupAttributes {
 		print "\t$attribute\n";
 	}
 
-	$attributes = $SCST->initiatorCreateAttributes($driver, $target, $group);
+	($attributes, $errorString) = $SCST->initiatorCreateAttributes($driver, $target, $group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 	return TRUE if (!scalar keys %{$attributes});
 
 	print "\n\tInitiator CREATE attributes available\n";
@@ -3597,9 +3675,9 @@ sub listLunAttributes {
 	my $lun = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->lunAttributes($driver, $target, $lun, $group);
+	my ($attributes, $errorString) = $SCST->lunAttributes($driver, $target, $lun, $group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		if ($group ne '') {
@@ -3620,16 +3698,16 @@ sub listInitiatorAttributes {
 	my $initiator = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->initiatorAttributes($driver, $target, $group, $initiator);
+	my ($attributes, $errorString) = $SCST->initiatorAttributes($driver, $target, $group, $initiator);
 
 	# As if writing, initiators didn't have attributes. This will
 	# allow us to support it in the future.
-	if ($SCST->errorString() =~ /Not a directory/) {
+	if ($errorString =~ /Not a directory/) {
 		print "Initiators do not (yet) have attributes.\n";
 		return;
 	}
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such driver/target/group/initiator '$driver/$target/$group/$initiator' found.\n";
@@ -3643,9 +3721,9 @@ sub listDeviceGroupAttributes {
 	my $group = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->deviceGroupAttributes($group);
+	my ($attributes, $errorString) = $SCST->deviceGroupAttributes($group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	# Special case - as of writing, device group attributes didn't exist.
 	if (!scalar(keys %{$attributes})) {
@@ -3661,9 +3739,9 @@ sub listTargetGroupAttributes {
 	my $tgroup = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->targetGroupAttributes($group, $tgroup);
+	my ($attributes, $errorString) = $SCST->targetGroupAttributes($group, $tgroup);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such device group/target group '$group/$tgroup' found.\n";
@@ -3679,9 +3757,9 @@ sub listTargetGroupTargetAttributes {
 	my $tgt = shift;
 	my $nonkey = shift;
 
-	my $attributes = $SCST->targetGroupTargetAttributes($group, $tgroup, $tgt);
+	my ($attributes, $errorString) = $SCST->targetGroupTargetAttributes($group, $tgroup, $tgt, TRUE);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	if (!scalar(keys %{$attributes})) {
 		print "No such device group/target group/target '$group/$tgroup/$tgt' found.\n";
@@ -3691,24 +3769,6 @@ sub listTargetGroupTargetAttributes {
 	return listAttributes($attributes, $nonkey);
 }
 
-sub listTargetGroupTargetAttributes {
-	my $group = shift;
-	my $tgroup = shift;
-	my $tgt = shift;
-	my $nonkey = shift;
-
-	my $attributes = $SCST->targetGroupTargetAttributes($group, $tgroup, $tgt);
-
-	return TRUE if issueWarning($SCST->errorString());
-
-	if (!scalar(keys %{$attributes})) {
-		print "No such target '$tgt' exists within specified target group.\n";
-		return;
-	}
-
-	return listAttributes($attributes, $nonkey);
-}
-
 ####################################################################
 
 sub setScstAttribute {
@@ -3731,9 +3791,9 @@ sub setScstAttributes {
 	my $showset = shift;
 
 	my $error = "\t-> WARNING: SCST lacks the settable attribute '%s', ignoring.\n\n";
-	my $_attributes = $SCST->scstAttributes();
+	my ($_attributes, $errorString) = $SCST->scstAttributes();
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, undef, undef, undef, $attributes,
 	  $_attributes, $error, \&setScstAttribute, $showset);
@@ -3761,9 +3821,9 @@ sub setDeviceAttributes {
 
 	my $error = "\t-> WARNING: Device '$device' lacks the settable ".
 	  "attribute '%s', ignoring.\n\n";
-	my $_attributes = $SCST->deviceAttributes($device);
+	my ($_attributes, $errorString) = $SCST->deviceAttributes($device);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, undef, undef, $device, $attributes,
 	  $_attributes, $error, \&setDeviceAttribute, $showset);
@@ -3791,9 +3851,9 @@ sub setHandlerAttributes {
 
 	my $error = "\t-> WARNING: Handler '$handler' lacks the settable ".
 	  "attribute '%s', ignoring.\n\n";
-	my $_attributes = $SCST->handlerAttributes($handler);
+	my ($_attributes, $errorString) = $SCST->handlerAttributes($handler);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, undef, undef, $handler, $attributes,
 	  $_attributes, $error, \&setHandlerAttribute, $showset);
@@ -3824,9 +3884,9 @@ sub setGroupAttributes {
 
 	my $error = "\t-> WARNING: Driver/target/group '$driver/$target/$group' lacks the settable ".
 	  "attribute '%s', ignoring.\n\n";
-	my $_attributes = $SCST->groupAttributes($driver, $target, $group);
+	my ($_attributes, $errorString) = $SCST->groupAttributes($driver, $target, $group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, $driver, $target, $group, $attributes,
 	  $_attributes, $error, \&setGroupAttribute, $showset);
@@ -3871,9 +3931,9 @@ sub setLunAttributes {
 		  "attribute '%s', ignoring.\n\n";
 	}
 
-	my $_attributes = $SCST->lunAttributes($driver, $target, $lun, $group);
+	my ($_attributes, $errorString) = $SCST->lunAttributes($driver, $target, $lun, $group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes($driver, $target, $lun, $group, $attributes,
 	  $_attributes, $error, \&setLunAttribute, $showset);
@@ -3904,13 +3964,13 @@ sub setInitiatorAttributes {
 	my $attributes = shift;
 	my $showset = shift;
 
-	my $_attributes = $SCST->initiatorAttributes($driver, $target, $group, $initiator);
+	my ($_attributes, $errorString) = $SCST->initiatorAttributes($driver, $target, $group, $initiator);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	# As if writing, initiators didn't have attributes. This will
 	# allow us to support it in the future.
-	if ($SCST->errorString() =~ /Not a directory/) {
+	if ($errorString =~ /Not a directory/) {
 		print "Initiators do not (yet) have attributes.\n";
 		return;
 	}
@@ -3922,6 +3982,35 @@ sub setInitiatorAttributes {
 	  $_attributes, $error, \&setInitiatorAttribute, $showset);
 }
 
+sub setAluaAttributes {
+	my $attributes = shift;
+	my $showset = shift;
+
+	my $error = "\t-> WARNING: no settable ALUA attribute '%s', ignoring.\n\n";
+
+	my ($_attributes, $errorString) = $SCST->aluaAttributes();
+
+	return TRUE if issueWarning($errorString);
+
+	return setAttributes(undef, undef, undef, undef, $attributes,
+	  $_attributes, $error, \&setAluaAttribute, $showset);
+}
+
+sub setAluaAttribute {
+	shift;
+	shift;
+	shift;
+	shift;
+	my $attribute = shift;
+	my $value = shift;
+
+	print "\t-> Setting ALUA attribute '$attribute' to value '$value': ";
+	my $rc = $SCST->setAluaAttribute($attribute, $value);
+	print "done.\n";
+
+	return $rc;
+}
+
 sub setDeviceGroupAttributes {
 	my $group = shift;
 	my $attributes = shift;
@@ -3929,9 +4018,9 @@ sub setDeviceGroupAttributes {
 
 	my $error = "\t-> WARNING: Device Group '$group' lacks the settable attribute '%s', ignoring.\n\n";
 
-	my $_attributes = $SCST->deviceGroupAttributes($group);
+	my ($_attributes, $errorString) = $SCST->deviceGroupAttributes($group);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, undef, undef, $group, $attributes,
 	  $_attributes, $error, \&setDeviceGroupAttribute, $showset);
@@ -3962,9 +4051,9 @@ sub setTargetGroupAttributes {
 
 	my $error = "\t-> WARNING: Target Group '$group/$tgroup' lacks the settable attribute '%s', ignoring.\n\n";
 
-	my $_attributes = $SCST->targetGroupAttributes($group, $tgroup);
+	my ($_attributes, $errorString) = $SCST->targetGroupAttributes($group, $tgroup);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, undef, $group, $tgroup, $attributes,
 	  $_attributes, $error, \&setTargetGroupAttribute, $showset);
@@ -3996,9 +4085,9 @@ sub setTargetGroupTargetAttributes {
 
 	my $error = "\t-> WARNING: Target '$group/$tgroup/$tgt' lacks the settable attribute '%s', ignoring.\n\n";
 
-	my $_attributes = $SCST->targetGroupTargetAttributes($group, $tgroup, $tgt);
+	my ($_attributes, $errorString) = $SCST->targetGroupTargetAttributes($group, $tgroup, $tgt, TRUE);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	return setAttributes(undef, $group, $tgroup, $tgt, $attributes,
 	  $_attributes, $error, \&setTargetGroupTargetAttribute, $showset);
@@ -4098,9 +4187,9 @@ sub setDriverAttributes {
 	my $changes = 0;
 
 	my $driverCap = $SCST->driverIsVirtualCapable($driver);
-	my $_attributes = $SCST->driverAttributes($driver);
+	my ($_attributes, $errorString) = $SCST->driverAttributes($driver);
 
-	return 0 if issueWarning($SCST->errorString());
+	return 0 if issueWarning($errorString);
 
 	# build caches for easier matching
 	foreach my $attribute (keys %{$attributes}) {
@@ -4171,9 +4260,9 @@ sub addDriverDynamicAttributes {
 	my $driver = shift;
 	my $attributes = shift;
 
-	my $_attributes = $SCST->driverAttributes($driver);
+	my ($_attributes, $errorString) = $SCST->driverAttributes($driver);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	my $existing = cacheAttributes($_attributes);
 
@@ -4199,7 +4288,7 @@ sub addDriverDynamicAttribute {
 	my $rc = $SCST->addDriverDynamicAttribute($driver, $attribute, $value);
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc); 
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4208,9 +4297,9 @@ sub removeDriverDynamicAttributes {
 	my $driver = shift;
 	my $attributes = shift;
 
-	my $_attributes = $SCST->driverAttributes($driver);
+	my ($_attributes, $errorString) = $SCST->driverAttributes($driver);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	my $existing = cacheAttributes($_attributes);
 
@@ -4238,7 +4327,7 @@ sub removeDriverDynamicAttribute {
 	my $rc = $SCST->removeDriverDynamicAttribute($driver, $attribute, $value);
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4260,7 +4349,7 @@ sub setTargetAttribute {
 	my $rc = $SCST->setTargetAttribute($driver, $target, $attribute, $value);
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4274,9 +4363,9 @@ sub setTargetAttributes {
 	my $changes = 0;
 
 	my $driverCap = $SCST->driverIsVirtualCapable($driver);
-	my $_attributes = $SCST->targetAttributes($driver, $target);
+	my ($_attributes, $errorString) = $SCST->targetAttributes($driver, $target);
 
-	return 0 if issueWarning($SCST->errorString());
+	return 0 if issueWarning($errorString);
 
 	# build caches for easier matching
 	foreach my $attribute (keys %{$attributes}) {
@@ -4350,9 +4439,9 @@ sub addTargetDynamicAttributes {
 	my $target = shift;
 	my $attributes = shift;
 
-	my $_attributes = $SCST->targetAttributes($driver, $target);
+	my ($_attributes, $errorString) = $SCST->targetAttributes($driver, $target);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	my $existing = cacheAttributes($_attributes);
 
@@ -4381,7 +4470,7 @@ sub addTargetDynamicAttribute {
 	my $rc = $SCST->addTargetDynamicAttribute($driver, $target, $attribute, $value);
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc); 
+	condExit($SCST->errorString($rc)); 
 
 	return FALSE;
 }
@@ -4391,9 +4480,9 @@ sub removeTargetDynamicAttributes {
 	my $target = shift;
 	my $attributes = shift;
 
-	my $_attributes = $SCST->targetAttributes($driver, $target);
+	my ($_attributes, $errorString) = $SCST->targetAttributes($driver, $target);
 
-	return TRUE if issueWarning($SCST->errorString());
+	return TRUE if issueWarning($errorString);
 
 	my $existing = cacheAttributes($_attributes);
 
@@ -4423,7 +4512,7 @@ sub removeTargetDynamicAttribute {
 	my $rc = $SCST->removeTargetDynamicAttribute($driver, $target, $attribute, $value);
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4441,7 +4530,7 @@ sub openDevice {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4451,7 +4540,7 @@ sub closeDevice {
 	my $device = shift;
 	my $force = shift;
 
-	my $attributes = $SCST->deviceAttributes($device);
+	my ($attributes, $errorString) = $SCST->deviceAttributes($device);
 
 	if (!$force) {
 		if (keys %{$$attributes{'exported'}}) {
@@ -4467,7 +4556,7 @@ sub closeDevice {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4490,7 +4579,7 @@ sub addDeviceGroup {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4505,7 +4594,7 @@ sub addTargetGroup {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4521,7 +4610,7 @@ sub addTargetGroupTarget {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4531,8 +4620,8 @@ sub removeDeviceGroup {
 	my $force = shift;
 
 	if (!$force) {
-		my $devices = $SCST->deviceGroupDevices($group);
-		my $tgroups = $SCST->targetGroups($group);
+		my ($devices, $errorString) = $SCST->deviceGroupDevices($group);
+		my ($tgroups, $errorString) = $SCST->targetGroups($group);
 
 		if (($#{$devices} > -1) || ($#{$tgroups} > -1)) {
 			print "\n";
@@ -4547,7 +4636,7 @@ sub removeDeviceGroup {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4558,7 +4647,7 @@ sub removeTargetGroup {
 	my $force = shift;
 
 	if (!$force) {
-		my $tgts = $SCST->targetGroupTargets($group, $tgroup);
+		my ($tgts, $errorString) = $SCST->targetGroupTargets($group, $tgroup);
 
 		if ($#{$tgts} > -1) {
 			print "\n";
@@ -4573,7 +4662,7 @@ sub removeTargetGroup {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4590,7 +4679,7 @@ sub removeTargetGroupTarget {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4605,7 +4694,7 @@ sub addDeviceGroupDevice {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4617,10 +4706,10 @@ sub removeDeviceGroupDevice {
 
 	if (!$force) {
 		my $found = FALSE;
-		my $tgroups = $SCST->targetGroups($group);
+		my ($tgroups, $errorString) = $SCST->targetGroups($group);
 
 		foreach my $tgroup (@{$tgroups}) {
-			my $targets = $SCST->targetGroupTargets($group, $tgroup);
+			my ($targets, $errorString) = $SCST->targetGroupTargets($group, $tgroup);
 
 			if ($#{$targets} > -1) {
 				print "\n";
@@ -4640,7 +4729,7 @@ sub removeDeviceGroupDevice {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4658,7 +4747,7 @@ sub addGroup {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4670,8 +4759,8 @@ sub removeGroup {
 	my $force = shift;
 
 	if (!$force) {
-		my $luns = $SCST->luns($driver, $target, $group);
-		my $initiators = $SCST->initiators($driver, $target, $group);
+		my ($luns, $errorString) = $SCST->luns($driver, $target, $group);
+		my ($initiators, $errorString) = $SCST->initiators($driver, $target, $group);
 
 		if ((keys %{$luns}) || ($#{$initiators} > -1)) {
 			listGroup($driver, $target, $group, $luns, $initiators);
@@ -4685,7 +4774,7 @@ sub removeGroup {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4719,7 +4808,7 @@ sub addInitiator {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4737,7 +4826,7 @@ sub removeInitiator {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4755,7 +4844,7 @@ sub moveInitiator {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4771,7 +4860,7 @@ sub clearInitiators {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4798,7 +4887,7 @@ sub addLun {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4821,7 +4910,7 @@ sub removeLun {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4841,7 +4930,7 @@ sub replaceLun {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4861,7 +4950,7 @@ sub clearLuns {
 
 	print "done.\n";
 
-	immediateExit($SCST->errorString($rc)) if ($rc);
+	condExit($SCST->errorString($rc));
 
 	return FALSE;
 }
@@ -4873,8 +4962,8 @@ sub clearDriverDynamicAttributes {
 
 	print "\t-> Removing all dynamic attributes from driver '$driver': ";
 
-	my $attributes = $SCST->driverAttributes($driver);
-	my $dynamic = $SCST->driverDynamicAttributes($driver);
+	my ($attributes, $errorString) = $SCST->driverAttributes($driver);
+	my ($dynamic, $errorString) = $SCST->driverDynamicAttributes($driver);
 
 	foreach my $attribute (keys %{$attributes}) {
 		if (defined($$dynamic{$attribute})) {
@@ -4883,7 +4972,7 @@ sub clearDriverDynamicAttributes {
 					my $value = $$attributes{$attribute}->{'keys'}->{$key}->{'value'};
 					my $rc = $SCST->removeDriverDynamicAttribute($driver, $attribute, $value);
 
-					immediateExit($SCST->errorString($rc)) if ($rc);
+					condExit($SCST->errorString($rc));
 				}
 			}
 		}
@@ -4902,8 +4991,8 @@ sub clearTargetDynamicAttributes {
 
 	print "\t-> Removing all dynamic attributes from driver/target '$driver/$target': ";
 
-	my $attributes = $SCST->targetAttributes($driver, $target);
-	my $dynamic = $SCST->targetDynamicAttributes($driver);
+	my ($attributes, $errorString) = $SCST->targetAttributes($driver, $target);
+	my ($dynamic, $errorString) = $SCST->targetDynamicAttributes($driver);
 
 	foreach my $attribute (keys %{$attributes}) {
 		if (defined($$dynamic{$attribute})) {
@@ -4912,7 +5001,7 @@ sub clearTargetDynamicAttributes {
 					my $value = $$attributes{$attribute}->{'keys'}->{$key}->{'value'};
 					my $rc = $SCST->removeTargetDynamicAttribute($driver, $target, $attribute, $value);
 
-					immediateExit($SCST->errorString($rc)) if ($rc);
+					condExit($SCST->errorString($rc));
 				}
 			}
 		}
@@ -4949,7 +5038,7 @@ sub enableDriver {
 	my $driver = shift;
 	my %attributes = ('enabled', 1);
 
-	my $attrs = $SCST->driverAttributes($driver);
+	my ($attrs, $errorString) = $SCST->driverAttributes($driver);
 	return TRUE if (!defined($$attrs{'enabled'}));
 
 	return setDriverAttributes($driver, \%attributes);
@@ -4959,7 +5048,7 @@ sub disableDriver {
 	my $driver = shift;
 	my %attributes = ('enabled', 0);
 
-	my $attrs = $SCST->driverAttributes($driver);
+	my ($attrs, $errorString) = $SCST->driverAttributes($driver);
 	return TRUE if (!defined($$attrs{'enabled'}));
 
 	return setDriverAttributes($driver, \%attributes);
@@ -4973,10 +5062,10 @@ sub issueLip {
 	if (defined($driver) && defined($target)) {
 		return _issueLip($driver, $target, $warn);
 	} else {
-		my $drivers = $SCST->drivers();
+		my ($drivers, $errorString) = $SCST->drivers();
 
 		foreach my $driver(@{$drivers}) {
-			my $targets = $SCST->targets($driver);
+			my ($targets, $errorString) = $SCST->targets($driver);
 
 			foreach my $target (@{$targets}) {
 				my $rc = _issueLip($driver, $target, $warn);
@@ -4995,7 +5084,7 @@ sub _issueLip {
 	my $warn = shift;
 	my $rc = FALSE;
 
-	my $attributes = $SCST->targetAttributes($driver, $target);
+	my ($attributes, $errorString) = $SCST->targetAttributes($driver, $target);
 
 	if (!defined($$attributes{'host'}) && $warn) {
 		print "\t-> Driver/target '$driver/$target' has no 'host' attribute, ignoring.\n";
@@ -5244,7 +5333,7 @@ sub readOldConfigFile {
 		}
 	}
 
-	my $drivers = $SCST->drivers();
+	my ($drivers, $errorString) = $SCST->drivers();
 	my %added_targets;
 
 	# Handle default groups
@@ -5256,7 +5345,7 @@ sub readOldConfigFile {
 				my($device, $lun) = split(/\,/, $device);
 
 				foreach my $driver (@{$drivers}) {
-					my $targets = $SCST->targets($driver);
+					my ($targets, $errorString) = $SCST->targets($driver);
 
 					foreach my $target (@{$targets}) {
 						$new{'TARGET_DRIVER'}->{$driver}->{'TARGET'}->{$target}->{'LUN'}->{$lun}->{$device} = {};
@@ -5269,7 +5358,7 @@ sub readOldConfigFile {
 			my $found_t = FALSE;
 			# Find the associated target
 			foreach my $driver (@{$drivers}) {
-				my $targets = $SCST->targets($driver);
+				my ($targets, $errorString) = $SCST->targets($driver);
 
 				foreach my $target (@{$targets}) {
 					if ($target eq $group_t) {
@@ -5310,7 +5399,7 @@ sub readOldConfigFile {
 			addAllGroupsToTarget(\%config, \%new, $driver, $target);
 			$has_enabled = TRUE;
 		} else {
-			immediateExit("Unable to determine target driver information for target '$wwn'. ".
+			condExit("Unable to determine target driver information for target '$wwn'. ".
 			  "Please ensure this target driver is loaded.");
 		}
 	}
@@ -5321,7 +5410,7 @@ sub readOldConfigFile {
 
 		# Fill in with known targets, all disabled.
 		foreach my $driver (@{$drivers}) {
-			my $targets = $SCST->targets($driver);
+			my ($targets, $errorString) = $SCST->targets($driver);
 
 			foreach my $target (@{$targets}) {
 				addAllGroupsToTarget(\%config, \%new, $driver, $target);
@@ -5340,7 +5429,7 @@ sub readOldConfigFile {
 	foreach my $driver (keys %{$new{'TARGET_DRIVER'}}) {
 		next if ($driver =~ /^qla/);
 
-		my $attributes = $SCST->driverAttributes($driver);
+		my ($attributes, $errorString) = $SCST->driverAttributes($driver);
 
 		if (defined($$attributes{'enabled'})) {
 			$new{'TARGET_DRIVER'}->{$driver}->{'enabled'}->{'1'} = {};
@@ -5516,6 +5605,19 @@ sub immediateExit {
 	exit 1;
 }
 
+# If an error occurred, exit if -cont_on_err has not been specified.
+sub condExit {
+	my $error = shift;
+
+	if (!$error) {
+		;
+	} elsif ($_CONT_ON_ERR_) {
+		print "$error\n";
+	} else {
+		immediateExit($error);
+	}
+}
+
 sub issueWarning {
 	my $error = shift;