From 08276e9f7ab258918fa440f23cf8c26e6be7527f Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@redhat.com>
Date: Fri, 21 Aug 2020 01:35:20 +0800
Subject: [PATCH] Rework check_config and warn on any duplicated option

Instead of read and parse the kdump.conf multiple times, only read once
and use a single loop to handle the error check, which is faster.

Also check for any duplicated config otion, and error out if there are
duplicated ones.

Now it checks for following errors, most are unchanged from before:
 - Any duplicated config options. (New added)
 - Deprecated/Invalid kdump config option.
 - Duplicated kdump target, will have a different error message of
   other duplicated config options.
 - Duplicated --mount options in dracut_args.
 - Empty config values. All kdump configs should be in
   "<config_opt> <config_value>" format.
 - Check If raw target is used in fadump mode.

And removed detect of lines start with space, it will not break kdump
anyway.

The performance is measurable better than before for the check_config
function.

Signed-off-by: Kairui Song <kasong@redhat.com>
Acked-by: Pingfan Liu <piliu@redhat.com>
---
 kdumpctl | 76 +++++++++++++++++++++++++++-----------------------------
 1 file changed, 36 insertions(+), 40 deletions(-)

diff --git a/kdumpctl b/kdumpctl
index 2248da4..f191d9a 100755
--- a/kdumpctl
+++ b/kdumpctl
@@ -217,62 +217,58 @@ restore_default_initrd()
 
 check_config()
 {
-	local nr
-
-	nr=$(awk 'BEGIN{cnt=0} /^raw|^ssh[[:blank:]]|^nfs|^ext[234]|^xfs|^btrfs|^minix|^dracut_args .*\-\-mount/{cnt++} END{print cnt}' $KDUMP_CONFIG_FILE)
-	[ $nr -gt 1 ] && {
-		echo "More than one dump targets specified."
-		return 1
-	}
-
-	# Check if path option is set more than once.
-        nr=$(awk 'BEGIN{cnt=0} /^path /{cnt++} END{print cnt}' $KDUMP_CONFIG_FILE)
-        [ $nr -gt 1 ] && {
-                echo "Mutiple paths specifed in $KDUMP_CONFIG_FILE"
-                return 1
-        }
-
-	nr=$(grep "^dracut_args .*\-\-mount" $KDUMP_CONFIG_FILE | grep -o "\-\-mount" | wc -l)
-	[ $nr -gt 1 ] && {
-		echo "Multiple mount targets specified in one \"dracut_args\"."
-		return 1
-	}
-
-	# Check if we have any leading spaces (or tabs) before the
-	# variable name in the kdump conf file
-	if grep -E -q '^[[:blank:]]+[a-z]' $KDUMP_CONFIG_FILE; then
-		echo "No whitespaces are allowed before a kdump option name in $KDUMP_CONFIG_FILE"
-		return 1
-	fi
-
+	local -A _opt_rec
 	while read config_opt config_val; do
+		if [ -z "$config_val" ]; then
+			echo "Invalid kdump config value for option $config_opt"
+			return 1
+		fi
+
 		case "$config_opt" in
-		\#* | "")
-			;;
-		raw|ext2|ext3|ext4|minix|btrfs|xfs|nfs|ssh|sshkey|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|failure_action|default|final_action|force_rebuild|force_no_rebuild|dracut_args|fence_kdump_args|fence_kdump_nodes)
-			# remove inline comments after the end of a directive.
-			[ -z "$config_val" ] && {
-				echo "Invalid kdump config value for option $config_opt."
-				return 1;
-			}
-			if [ -d "/proc/device-tree/ibm,opal/dump" ] && [ "$config_opt" == "raw" ]; then
-				echo "WARNING: Won't capture opalcore when 'raw' dump target is used."
+		dracut_args)
+			if [[ $config_val == *--mount* ]]; then
+				if [ $(echo $config_val | grep -o "\-\-mount" | wc -l) -ne 1 ]; then
+					echo "Multiple mount targets specified in one \"dracut_args\"."
+					return 1
+				fi
+				config_opt=_target
 			fi
 			;;
+		raw)
+			if [ -d "/proc/device-tree/ibm,opal/dump" ]; then
+				echo "WARNING: Won't capture opalcore when 'raw' dump target is used."
+				return 1
+			fi
+			config_opt=_target
+			;;
+		ext[234]|minix|btrfs|xfs|nfs|ssh)
+			config_opt=_target
+			;;
+		sshkey|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|failure_action|default|final_action|force_rebuild|force_no_rebuild|fence_kdump_args|fence_kdump_nodes)
+			;;
 		net|options|link_delay|disk_timeout|debug_mem_level|blacklist)
 			echo "Deprecated kdump config option: $config_opt. Refer to kdump.conf manpage for alternatives."
 			return 1
 			;;
 		*)
 			echo "Invalid kdump config option $config_opt"
-			return 1;
+			return 1
 			;;
 		esac
+
+		if [ -n "${_opt_rec[$config_opt]}" ]; then
+			if [ $config_opt == _target ]; then
+				echo "More than one dump targets specified"
+			else
+				echo "Duplicated kdump config value of option $config_opt"
+			fi
+			return 1
+		fi
+		_opt_rec[$config_opt]="$config_val"
 	done <<< "$(read_strip_comments $KDUMP_CONFIG_FILE)"
 
 	check_failure_action_config || return 1
 	check_final_action_config || return 1
-
 	check_fence_kdump_config || return 1
 
 	return 0