From d9d0cfd42ccdee03085f36fed194d850622804b9 Mon Sep 17 00:00:00 2001
From: chenglch <chenglch@cn.ibm.com>
Date: Thu, 8 Jun 2017 11:21:26 +0800
Subject: [PATCH] Avoid of circular reference in a loop of rinstall (#3121)

This is a temporary fix for getadapter which will hang forever if
error happens in `rinstall stage`. The root cause is the circular
reference in `runxcmd`. As global variable `$::xcmd_outref` and
`%::xcmd_outref_hash` are used to save the output message, if the
plugin command are called with runxcmd and the plugin called also
calls another plugin with `runxcmd`, the circular reference will happen.
In this situation, if the output reponse is used in a iterator,
like:
```
   foreach my $line (@$res) {
      xCAT::MsgUtils->message("I", $rsp, $callback);
```
`$res` points to the global variable, and `MsgUtils->message` in the
runxcmd calls also add the value in the global variable, as the
iter object is changed, the loop will not be terminated.

This patch can not solve the circular reference problem, it is just
a workaround to avoid infinite loop.

Some known issues: the error message will print twice as the
`MsgUtils->message` called in runxcmd. But we can not simply remove
it as the plugin may not be called with `runxcmd`.

Error message example:

```
Error: frame10node10: mgt configuration can not be found.
frame10node10: Unable to identify plugin for this command, check relevant tables: noderes.netboot
frame10node10: Unable to identify plugin for this command, check relevant tables: noderes.netboot
Failed to run 'nodeset' against the following nodes: frame10node10
Error: failed to run command: rinstall frame10node10 runcmd=getadapter
```
partial-fix: #3046
---
 xCAT-server/lib/xcat/plugins/rinstall.pm | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/xCAT-server/lib/xcat/plugins/rinstall.pm b/xCAT-server/lib/xcat/plugins/rinstall.pm
index 4fba96ed0..906746b33 100644
--- a/xCAT-server/lib/xcat/plugins/rinstall.pm
+++ b/xCAT-server/lib/xcat/plugins/rinstall.pm
@@ -351,7 +351,9 @@ sub rinstall {
         # We got an error with the nodeset
         my @successnodes;
         my @failurenodes;
-        foreach my $line (@$res) {
+        # copy into a temporary variable to avoid of circular reference
+        my @lines = @$res;
+        foreach my $line (@lines) {
             $rsp->{data}->[0] = $line;
             if (($line =~ /: install/) or ($line =~ /: netboot/)) {
                 my $successnode;
@@ -414,7 +416,6 @@ sub rinstall {
                 },
                 $subreq, -1, 1);
 
-
             $rc = $::RUNCMD_RC;
             my $rsp = {};
             if ($VERBOSE) {
@@ -427,7 +428,9 @@ sub rinstall {
 
                 # We got an error with the rnetboot
                 my @failurenodes;
-                foreach my $line (@$res) {
+                # copy into a temporary variable to avoid of circular reference
+                my @lines = @$res;
+                foreach my $line (@lines) {
                     $rsp->{data}->[0] = $line;
                     if ($line =~ /: Success/) {
                         my $successnode;
@@ -491,7 +494,9 @@ sub rinstall {
                     # We got an error with the rsetboot
                     my @successnodes;
                     my @failurenodes;
-                    foreach my $line (@$res) {
+                    # copy into a temporary variable to avoid of circular reference
+                    my @lines = @$res;
+                    foreach my $line (@lines) {
                         $rsp->{data}->[0] = $line;
                         if ($line =~ /: Network/) {
                             my $successnode;
@@ -550,7 +555,9 @@ sub rinstall {
             unless ($rc == 0) {
                 # We got an error with the rpower
                 my @failurenodes;
-                foreach my $line (@$res) {
+                # copy into a temporary variable to avoid of circular reference
+                my @lines = @$res;
+                foreach my $line (@lines) {
                     $rsp->{data}->[0] = $line;
                     if (($line =~ /: on reset/) or ($line =~ /: off on/)) {
                         my $successnode;