add function to check kdump config file

Add a function check_config to check kdump config file.
1. move multi dump target checking into this function
2. check invalid config options and obsolete config options
3. check null config value.

[v2->v3]: add detail doc about deprecated options in kdump.conf manpage.
[v3->v4]: print out the bad config option in case it is not valid.
[v4->v5]: improve documentation according to comments from Vivek.
[v5->v6]: s/Deprecated/Invalid for invalid config options.

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Acked-by: Marc Milgram <mmilgram@redhat.com>

kdump.conf.5

@@ -167,6 +167,53 @@ By default, kdump initrd only will be rebuilt when necessary.
 Specify 1 to force rebuilding kdump initrd every time when kdump service starts.
 .RE
 
+.SH DEPRECATED OPTIONS
+
+.B net <nfs mount>|<user@server>
+.RS
+net option is replaced by nfs and ssh options. Use nfs or ssh options
+directly.
+.RE
+
+.B options <module> <option list>
+.RS
+Use KDUMP_COMMANDLINE_APPEND in /etc/sysconfig/kdump to add proper
+module option as kernel command line params. Such as append loop.max_loop=1
+to limit maximum loop devices to 1.
+.RE
+
+.B link_delay <seconds>
+.RS
+link_delay was used to wait a network device to initialize before using it.
+Now dracut network module take care of this issue automaticlly.
+.RE
+
+.B disk_timeout <seconds>
+.RS
+Similar to link_delay, dracut ensures disks being ready before kdump uses them.
+.RE
+
+.B debug_mem_level <0-3>
+.RS
+This was used to turns on debug/verbose output of kdump scripts regarding
+free/used memory at various points of execution.  This feature has been
+moved to dracut now.
+Use KDUMP_COMMANDLINE_APPEND in /etc/sysconfig/kdump and
+append dracut cmdline param rd.memdebug=[0-3] to enable the debug output.
+
+Higher level means more debugging output.
+.PP
+0 - no output
+.PP
+1 - partial /proc/meminfo
+.PP
+2 - /proc/meminfo
+.PP
+3 - /proc/meminfo + /proc/slabinfo
+.RE
+
+.RE
+
 .SH EXAMPLES
 Here is some examples for core_collector option:
 .PP

kdumpctl

@@ -72,6 +72,39 @@ function check_executable()
 	done
 }
 
+function check_config()
+{
+	local nr
+
+	nr=$(awk 'BEGIN{cnt=0} /^raw|^ssh[[:blank:]]|^nfs|^ext[234]|^xfs|^btrfs|^minix/{cnt++} END{print cnt}' $KDUMP_CONFIG_FILE)
+	[ $nr -gt 1 ] && {
+		echo "More than one dump targets specified."
+		return 1
+	}
+
+	while read config_opt config_val; do
+		case "$config_opt" in
+		\#* | "")
+			;;
+		raw|ext2|ext3|ext4|minix|btrfs|xfs|nfs|ssh|sshkey|blacklist|path|core_collector|kdump_post|kdump_pre|extra_bins|extra_modules|default|force_rebuild)
+			[ -z "$config_val" ] && {
+				echo "Invalid kdump config value for option $config_opt."
+				return 1;
+			}
+			;;
+		net|options|link_delay|disk_timeout|debug_mem_level)
+			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;
+			;;
+		esac
+	done < $KDUMP_CONFIG_FILE
+	return 0
+}
+
 function check_rebuild()
 {
 	local extra_modules modified_files=""
@@ -347,12 +380,11 @@ function save_raw()
 
 function start()
 {
-	local nr
-	nr=$(awk 'BEGIN{cnt=0} /^raw|^ssh[[:blank:]]|^nfs|^ext[234]|^xfs|^btrfs|^minix/{cnt++} END{print cnt}' $KDUMP_CONFIG_FILE)
-	[ $nr -gt 1 ] && {
-		echo "More than one dump targets specified: [WARNING]"
+	check_config
+	if [ $? -ne 0 ]; then
+		echo "Starting kdump: [FAILED]"
 		return 1
-	}
+	fi
 
 	save_raw
 	if [ $? -ne 0 ]; then

mkdumprd

@@ -268,10 +268,6 @@ do
             exit 1
         fi
         ;;
-    net)
-        echo "net option is not supported anymore, please use nfs|ssh instead."
-        exit 1
-        ;;
     core_collector)
         verify_core_collector "$config_val"
         ;;