[PATCH v3 1/3] kdumpctl: Add reload support

[Kairui Song]

Add reload support to kdumpctl, reload will simply unload current
loaded kexec crash kernel and initramfs, and load it again.

Changes in /etc/sysconfig/kdump will take effect with kdumpctl
reload, but reloading will not check the content of
/etc/kdump.conf and won't rebuild anything. reload is fast, the only
time-consuming part of kdumpctl reload is loading kernel and initramfs
with kexec which is always necessary.

Signed-off-by: Kairui Song <kasong(a)redhat.com&gt;
---
 kdump.service |  1 +
 kdumpctl      | 59 +++++++++++++++++++++++++++++++++++++++++++--------
 2 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/kdump.service b/kdump.service
index 5144597..f888dd6 100644
--- a/kdump.service
+++ b/kdump.service
@@ -7,6 +7,7 @@ DefaultDependencies=no
 Type=oneshot
 ExecStart=/usr/bin/kdumpctl start
 ExecStop=/usr/bin/kdumpctl stop
+ExecReload=/usr/bin/kdumpctl reload
 RemainAfterExit=yes
 StartLimitInterval=0
 
diff --git a/kdumpctl b/kdumpctl
index ece406f..6236f21 100755
--- a/kdumpctl
+++ b/kdumpctl
@@ -283,6 +283,16 @@ get_pcs_cluster_modified_files()
 
 setup_initrd()
 {
+	KDUMP_BOOTDIR=$(check_boot_dir "${KDUMP_BOOTDIR}")
+
+	if [ -z "$KDUMP_KERNELVER" ]; then
+		kdump_kver=`uname -r`
+	else
+		kdump_kver=$KDUMP_KERNELVER
+	fi
+
+	kdump_kernel="${KDUMP_BOOTDIR}/${KDUMP_IMG}-${kdump_kver}${KDUMP_IMG_EXT}"
+
 	DEFAULT_INITRD="${KDUMP_BOOTDIR}/initramfs-`uname -r`.img"
 	DEFAULT_INITRD_BAK="${KDUMP_BOOTDIR}/.initramfs-`uname -r`.img.default"
 	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
@@ -533,16 +543,8 @@ check_rebuild()
 	local _force_no_rebuild force_no_rebuild="0"
 	local ret system_modified="0"
 
-	KDUMP_BOOTDIR=$(check_boot_dir "${KDUMP_BOOTDIR}")
-
-	if [ -z "$KDUMP_KERNELVER" ]; then
-		kdump_kver=`uname -r`
-	else
-		kdump_kver=$KDUMP_KERNELVER
-	fi
-
-	kdump_kernel="${KDUMP_BOOTDIR}/${KDUMP_IMG}-${kdump_kver}${KDUMP_IMG_EXT}"
 	setup_initrd
+
 	if [ $? -ne 0 ]; then
 		return 1
 	fi
@@ -1004,6 +1006,42 @@ start()
 	echo "Starting kdump: [OK]"
 }
 
+reload()
+{
+	check_current_status
+	if [ $? -ne 0 ]; then
+		echo "Kdump is not running: [WARNING]"
+		return 0
+	fi
+
+	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
+		stop_fadump
+	else
+		stop_kdump
+	fi
+
+	if [ $? -ne 0 ]; then
+		echo "Stopping kdump: [FAILED]"
+		return 1
+	fi
+
+	echo "Stopping kdump: [OK]"
+
+	setup_initrd
+	if [ $? -ne 0 ]; then
+		echo "Starting kdump: [FAILED]"
+		return 1
+	fi
+
+	start_dump
+	if [ $? -ne 0 ]; then
+		echo "Starting kdump: [FAILED]"
+		return 1
+	fi
+
+	echo "Starting kdump: [OK]"
+}
+
 stop_fadump()
 {
 	echo 0 > $FADUMP_REGISTER_SYS_NODE
@@ -1087,6 +1125,9 @@ main ()
 		esac
 		exit $EXIT_CODE
 		;;
+	  reload)
+		reload
+		;;
 	  restart)
 		stop
 		start
-- 
2.17.1