From 4be7ffa4da4e5abc21ad217bf5e7933e4eb0f762 Mon Sep 17 00:00:00 2001
From: Mark Buechler <mark.buechler@gmail.com>
Date: Wed, 23 Sep 2009 14:58:19 +0000
Subject: [PATCH] - Replace a device on a given LUN when applying the
 configuration instead of removing   the old device and assigning the new one.

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@1131 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 scstadmin/ChangeLog                    |  2 +
 scstadmin/scst-0.8.21/lib/SCST/SCST.pm |  2 +-
 scstadmin/scstadmin                    | 59 +++++++++++++++++---------
 3 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/scstadmin/ChangeLog b/scstadmin/ChangeLog
index f5560d6e1..844acb428 100644
--- a/scstadmin/ChangeLog
+++ b/scstadmin/ChangeLog
@@ -2,6 +2,8 @@ Changes for 1.0.9
 
 - Move a user from one group to another when applying the configuration instead
   of deleting from one and adding to another the same user.
+- Replace a device on a given LUN when applying the configuration instead of removing
+  the old device and assigning the new one.
 - Add the ability to specify options (ie: READ_ONLY) in assignments in scst.conf.
 - Remove unused references to handler IOs that don't exist and cleanup the write
   configuration function to only write vdisk and vcdrom devices. All other devices
diff --git a/scstadmin/scst-0.8.21/lib/SCST/SCST.pm b/scstadmin/scst-0.8.21/lib/SCST/SCST.pm
index b845d3b5b..d8302c27d 100644
--- a/scstadmin/scst-0.8.21/lib/SCST/SCST.pm
+++ b/scstadmin/scst-0.8.21/lib/SCST/SCST.pm
@@ -915,7 +915,7 @@ sub replaceDeviceInGroup {
 	($options, $valid_opts) = $self->checkOptions($options, 'ASSIGN');
 
 	if (!$valid_opts) {
-		$self->{'error'} = "assignDeviceToGroup(): Invalid option(s) '$options' given for ".
+		$self->{'error'} = "replaceDeviceInGroup(): Invalid option(s) '$options' given for ".
 		  "device '$newDevice'";
 		return 1;
 	}
diff --git a/scstadmin/scstadmin b/scstadmin/scstadmin
index b610ec782..03d68dd7b 100755
--- a/scstadmin/scstadmin
+++ b/scstadmin/scstadmin
@@ -703,9 +703,10 @@ sub applyConfiguration {
 				foreach my $device (sort keys %{$_assignments}) {
 					if (!defined($used_assignments{$group}->{$device}) ||
 					   ($$_assignments{$device} != $used_assignments{$group}->{$device})) {
-						if ($$_assignments{$device} != $used_assignments{$group}->{$device}) {
-							print "\t-> WARNING: Device '$device' assigned to group '$group' is at LUN ".
-							  $used_assignments{$group}->{$device}.
+						if (defined($used_assignments{$group}->{$device}) &&
+						    ($$_assignments{$device} != $used_assignments{$group}->{$device})) {
+							print "\t-> WARNING: Device '$device' assigned to group '$group' ".
+							  "is at LUN ".$used_assignments{$group}->{$device}.
 							  " whereas working configuration reflects LUN ".$$_assignments{$device}; 
 						} else {
 							print "\t-> WARNING: Device '$device' is not associated with group ".
@@ -713,11 +714,25 @@ sub applyConfiguration {
 						}
 
 						if (!$check) {
-							print ", releasing.\n";
-							if (releaseDevice($group, $device)) {
-								$errs++;
+							my $_lun = $$_assignments{$device};
+
+							my $replace_dev = findAssignedLun($used_assignments{$group}, $_lun);
+
+							if (defined($replace_dev) && ($replace_dev ne $device)) {
+								print ", replacing with device '$replace_dev'.\n";
+
+								if (replaceDevice($group, $replace_dev, $_lun)) {
+									$errs++;
+								} else {
+									$changes++;
+								}
 							} else {
-								$changes++;
+								print ", releasing.\n";
+								if (releaseDevice($group, $device)) {
+									$errs++;
+								} else {
+									$changes++;
+								}
 							}
 						} else {
 							print ".\n";
@@ -953,6 +968,14 @@ sub applyConfiguration {
 				  ", whereas the working configuration reflects LUN $lun.\n".
 		 	          "\t   Use -ForceConfig to force this LUN change.\n" if (!$force && !$check);
 			} else {
+				my $replace_dev = findAssignedLun($_assignments, $lun);
+
+				if (defined($replace_dev) && ($vname ne $replace_dev)) {
+					print "\t-> WARNING: Use -ForceConfig to replace device '$replace_dev' ".
+					  "with device '$vname' for group '$group'.\n" if (!$force);
+					next;
+				}
+
 				if ($check) {
 					$lun = 'auto' if (!defined($lun));
 					print "\t-> New device assignment for '$vname' to group '$group' at LUN $lun.\n";
@@ -1722,27 +1745,21 @@ sub findUserGroupInCurrent {
 	return undef;
 }
 
-sub findDeviceGroup {
-	my $device = shift;
-	my $config = shift;
+sub findAssignedLun {
+	my $associations = shift;
+	my $lun = shift;
 
-	foreach my $group (keys %{$$config{'ASSIGNMENT'}}) {
-		foreach my $device (@{$$config{'ASSIGNMENT'}->{$group}->{'DEVICE'}}) {
-			my($vname, $arg) = split(/\,/, $device, 2);
-			$vname = cleanupString($vname);
-			return $group if ($vname eq $device);
+	return undef if (!defined($lun));
+
+	foreach my $device (keys %{$associations}) {
+		if ($$associations{$device} == $lun) {
+			return $device;
 		}
 	}
 
 	return undef;
 }
 
-sub findDeviceGroupInCurrent {
-	my $device = shift;
-
-	return undef;
-}
-
 sub cleanupString {
 	my $string = shift;