From 51efbcf83e26a69fb56466a580b50e5d4867509f Mon Sep 17 00:00:00 2001
From: Pingfan Liu <piliu@redhat.com>
Date: Tue, 13 Jun 2023 17:43:20 +0800
Subject: [PATCH] kdump-lib: Introduce a help function _crashkernel_add()

This help function can manipulate the crashkernel cmdline by adding an
number for each item. Also a basic test case for _crashkernel_add() is
provided in this patch.

Credit to Philipp, who contributes the original code.

Signed-off-by: Pingfan Liu <piliu@redhat.com>
Reviewed-by: Coiby Xu <coxu@redhat.com>
Reviewed-by: Philipp Rudo <prudo@redhat.com>
---
 kdump-lib.sh           | 58 ++++++++++++++++++++++++++++++++++++++++++
 spec/kdump-lib_spec.sh | 20 +++++++++++++++
 2 files changed, 78 insertions(+)

diff --git a/kdump-lib.sh b/kdump-lib.sh
index c6bf378..992e8d9 100755
--- a/kdump-lib.sh
+++ b/kdump-lib.sh
@@ -786,6 +786,64 @@ get_recommend_size()
 	echo "0M"
 }
 
+# $1 crashkernel=""
+# $2 delta in unit of MB
+_crashkernel_add()
+{
+	local _ck _add _entry _ret
+	local _range _size _offset
+
+	_ck="$1"
+	_add="$2"
+	_ret=""
+
+	if [[ "$_ck" == *@* ]]; then
+		_offset="@${_ck##*@}"
+		_ck=${_ck%@*}
+	elif [[ "$_ck" == *,high ]] || [[ "$_ck" == *,low ]]; then
+		_offset=",${_ck##*,}"
+		_ck=${_ck%,*}
+	else
+		_offset=''
+	fi
+
+	while read -d , -r _entry; do
+		[[ -n "$_entry" ]] || continue
+		if [[ "$_entry" == *:* ]]; then
+			_range=${_entry%:*}
+			_size=${_entry#*:}
+		else
+			_range=""
+			_size=${_entry}
+		fi
+
+		case "${_size: -1}" in
+			K)
+				_size=${_size::-1}
+				_size="$((_size + (_add * 1024)))K"
+				;;
+			M)
+				_size=${_size::-1}
+				_size="$((_size + _add))M"
+				;;
+			G)
+				_size=${_size::-1}
+				_size="$((_size * 1024 + _add))M"
+				;;
+			*)
+				_size="$((_size + (_add * 1024 * 1024)))"
+				;;
+		esac
+
+		[[ -n "$_range" ]] && _ret+="$_range:"
+		_ret+="$_size,"
+	done <<< "$_ck,"
+
+	_ret=${_ret%,}
+	[[ -n "$_offset" ]] && _ret+=$_offset
+	echo "$_ret"
+}
+
 # get default crashkernel
 # $1 dump mode, if not specified, dump_mode will be judged by is_fadump_capable
 kdump_get_arch_recommend_crashkernel()
diff --git a/spec/kdump-lib_spec.sh b/spec/kdump-lib_spec.sh
index 3d10006..81f0f86 100644
--- a/spec/kdump-lib_spec.sh
+++ b/spec/kdump-lib_spec.sh
@@ -48,6 +48,26 @@ Describe 'kdump-lib'
 		End
 	End
 
+	Describe "_crashkernel_add()"
+		Context "when the input parameter is '1G-4G:256M,4G-64G:320M,64G-:576M'"
+			delta=100
+			Parameters
+				"1G-4G:256M,4G-64G:320M,64G-:576M" "1G-4G:356M,4G-64G:420M,64G-:676M"
+				"1G-4G:256M,4G-64G:320M,64G-:576M@4G" "1G-4G:356M,4G-64G:420M,64G-:676M@4G"
+				"1G-4G:1G,4G-64G:2G,64G-:3G@4G" "1G-4G:1124M,4G-64G:2148M,64G-:3172M@4G"
+				"1G-4G:10000K,4G-64G:20000K,64G-:40000K@4G" "1G-4G:112400K,4G-64G:122400K,64G-:142400K@4G"
+				"300M,high" "400M,high"
+				"300M,low" "400M,low"
+				"500M@1G" "600M@1G"
+			End
+			It "should add delta to the values after ':'"
+
+				When call _crashkernel_add "$1" "$delta"
+				The output should equal "$2"
+			End
+		End
+	End
+
 	Describe 'prepare_cmdline()'
 		get_bootcpu_apicid() {
 			echo 1