From dab60da8173a3ce4492e86bb21b0ab2877759c66 Mon Sep 17 00:00:00 2001
From: Thomas Schoebel-Theuer <schoebel@bell.site>
Date: Fri, 3 May 2013 23:11:15 +0200
Subject: [PATCH] marsadm: allow calling multiple functions in phases

Add infrastructure for splitting commands in multiple phases.
Usually, phase0 will check for some preconditions, while
phase1 will execute the command. The final result will only
be committed if nothing fails.

The difference to the old behaviour will only show up when combined
with 'all' resources. If anything fails in phase0, nothing will be
touched in phase1. The old behaviour could touch some resources,
but omit others when something failed.

The new behaviour is more transactional-like.
---
 userspace/marsadm | 98 ++++++++++++++++++++++++++++++++---------------
 1 file changed, 68 insertions(+), 30 deletions(-)

diff --git a/userspace/marsadm b/userspace/marsadm
index 95028c58..7dd03f39 100755
--- a/userspace/marsadm
+++ b/userspace/marsadm
@@ -11,30 +11,27 @@ umask 0077;
 
 # messaging
 
-my $warn = "";
+my $error_count = 0;
 my $notify = "";
 
 sub lprint {
   my ($text) = @_;
-  print "$warn$text";
+  print $text;
   if ($notify) {
-    system("/usr/bin/logger -t marsadm \"$warn$notify $text\"");
+    system("/usr/bin/logger -t marsadm \"$notify $text\"");
   }
 }
 
 sub ldie {
   my ($text) = @_;
-  $warn = "DYING: ";
-  lprint $text;
-  exit -1;
+  $error_count++;
+  lprint "DYING: $text";
+  die "\n";
 }
 
 sub lwarn {
   my ($text) = @_;
-  my $oldwarn = $warn;
-  $warn = "WARNING: ";
-  lprint $text;
-  $warn = $oldwarn;
+  lprint "WARNING: $text";
 }
 
 ##################################################################
@@ -667,23 +664,21 @@ sub _set_replaylink {
 sub ignore_cmd {
   my ($cmd, $res) = @_;
   lprint "ignoring command '$cmd' on resource '$res'\n";
-  exit(0);
 }
 
 sub senseless_cmd {
   my ($cmd, $res) = @_;
-  lprint "command '$cmd' makes no sense with MARS (ignoring)\n";
-  exit(0);
+  lprint "command '$cmd' makes no sense with MARS (ignoring on resource '$res')\n";
 }
 
 sub forbidden_cmd {
   my ($cmd, $res) = @_;
-  ldie "command '$cmd' cannot be used with MARS (it is impossible to carry out uniquely and could therefore lead to a disaster)\n";
+  ldie "command '$cmd' on resource '$res' cannot be used with MARS (migth affect too many hosts, lead to undesired consequences)\n";
 }
 
 sub nyi_cmd {
   my ($cmd, $res) = @_;
-  ldie "command '$cmd' is not yet implemented\n";
+  ldie "command '$cmd'  on resource '$res' is not yet implemented\n";
 }
 
 sub is_module_loaded {
@@ -1126,7 +1121,7 @@ sub primary_res {
   if ($sec) {
     if ($old eq '(none)') {
       lprint "resource '$res' is already designated as secondary everywhere\n";
-      exit(0);
+      return;
     }
     if (($old ne $host) && !$force && (_get_actual_primary($res) ne $host)) {
       ldie "for safety reasons, switching to secondary is only allowed when I ($host) am designated primary or actually primary for resource '$res'\n";
@@ -1134,7 +1129,7 @@ sub primary_res {
     $new = "(none)";
   } elsif ($old eq $new) {
     lprint "I am already designated primary on resource '$res'.\n";
-    exit(0);
+    return;
   } elsif ($force) {
     lprint "FORCING myself ($host) to be the designated primary...\n";
   } elsif (! -d "/proc/sys/mars") {
@@ -1452,27 +1447,70 @@ if ($cmd eq "show") {
 
 lprint "using FORCE option -- hopefully you know what you do!\n" if $force;
 
-sub do_res {
-  my $cmd = shift;
-  my $res = shift;
+sub do_one_res {
+  my $func = shift;
+  my ($cmd, $res) = @_;
 
   $res = check_res($res) unless $cmd =~ m/^(join|create|leave)-cluster|create-resource|show$/;
   check_res_member($res) unless $cmd =~ m/^(join|create)-(cluster|resource)|leave-cluster|show$/;
 
-  my $func = $cmd_table{$cmd};
-  &{$func}($cmd, $res, @_);
+  &{$func}(@_);
 }
 
-if ($res eq "all" && $cmd ne "show") {
-  ldie "For safty reasons, --force is only allowed on explicitly named resources. Combination of 'all' with --force is disallowed!\n" if $force;
-  foreach $res (glob("$mars/resource-*")) {
-    next unless -e "$res/data-$host";
-    $res =~ s/^.*\/resource-(.*)$/$1/;
-    lprint "--------- resource $res\n";
-    do_res($cmd, $res, @args);
+my %skip_res;
+
+sub do_all_res {
+  my $func = shift;
+  my $cmd = shift;
+  my $res = shift || "all";
+  if ($res eq "all" && $cmd !~ m/show|cluster/) {
+    ldie "For safety reasons, --force is only allowed on explicitly named resources. Combination of 'all' with --force is disallowed!\n" if $force;
+    ldie "Cannot combine command '$cmd' with 'all' existing resources - you must explicitly name a single new resource\n" if $cmd =~ m/create|join/;
+    my $any_success = 0;
+    my $any_member = 0;
+    foreach $res (glob("$mars/resource-*")) {
+      next unless -e "$res/data-$host";
+      $any_member++;
+      $res =~ s/^.*\/resource-(.*)$/$1/;
+      next if defined($skip_res{$res});
+      lprint "--------- resource $res\n";
+      eval {
+	do_one_res($func, $cmd, $res, @_);
+	1;
+      } and $any_success = 1 or $skip_res{$res} = 1;
+    }
+    if (!$any_success) {
+      if (!$any_member) {
+	lprint "I am not member of any resource\n";
+	return 1;
+      }
+      ldie "all resources have errors\n";
+    }
+    return !$any_success;
+  } else {
+    return do_one_res($func, $cmd, $res, @_);
   }
+}
+
+my $func = $cmd_table{$cmd};
+ldie "unknown command '$cmd'\n" unless $func;
+
+if (ref($func) eq "ARRAY") {
+  my @list = @$func;
+  while (@list) {
+    my $headline = shift @list;
+    my $memb_func = shift @list;
+    lprint "---------------------------- $headline:\n";
+    my $status = do_all_res($memb_func, $cmd, $res, @args);
+    last if (defined($status) && $status);
+    finish_links();
+  }
+} elsif (ref($func) eq "CODE") {
+  do_all_res($func, $cmd, $res, @args);
 } else {
-  do_res($cmd, $res, @args);
+  ldie "internal error: command table is wrong for '$cmd'";
 }
 
 finish_links();
+
+exit($error_count);