Re: [PATCH 2/2] fadump: restore default initrd when fadump mode is disabled

[Dave Young]

Hi, Hari

The fix looks good, but I have a question about the kernel version
maybe we did not notice it when we review previous fadump patches.

On 09/07/16 at 06:10pm, Hari Bathini wrote:
>  When fadump mode is enabled, the default initrd is rebuilt with
> kdump
>  dracut module. As the default initrd is altered, the original default
>  initrd is backed up. But we are not restoring it when fadump mode is
>  disabled. This patch tries to restore the backed up default initrd on
>  disabling fadump mode.
>  
>  Signed-off-by: Hari Bathini <hbathini(a)linux.vnet.ibm.com&gt;
>  ---
>   kdumpctl |   42 ++++++++++++++++++++++++++++++++----------
>   1 file changed, 32 insertions(+), 10 deletions(-)
>  
>  diff --git a/kdumpctl b/kdumpctl
>  index 8d0ab81..8d883de 100755
>  --- a/kdumpctl
>  +++ b/kdumpctl
>  @@ -154,9 +154,6 @@ rebuild_fadump_initrd()
>   {
>   	local target_initrd_tmp
>   
>  -	# backup fadump initrd for reference before replacing it
>  -	backup_initrd
>  -
>   	# this file tells the initrd is fadump enabled
>   	touch /tmp/fadump.initramfs
>   	target_initrd_tmp="$TARGET_INITRD.tmp"
>  @@ -190,8 +187,17 @@ rebuild_kdump_initrd()
>   rebuild_initrd()
>   {
>   	if [ $DEFAULT_DUMP_MODE == "fadump" ]; then
>  +		# backup initrd for reference before replacing it
>  +		# with fadump aware initrd
>  +		backup_restore_default_initrd "backup"
>  +
>   		rebuild_fadump_initrd
>   	else
>  +		# check if a backup of default initrd exists. If yes,
>  +		# it signifies a switch from fadump mode. So, restore
>  +		# the backed up default initrd.
>  +		backup_restore_default_initrd "restore"
>  +
>   		rebuild_kdump_initrd
>   	fi
>   
>  @@ -220,15 +226,31 @@ check_executable()
>   	done
>   }
>   
>  -backup_initrd()
>  +backup_restore_default_initrd()
>   {
>  -	local target_initrd_bak
>  +	local default_initrd
>  +	local default_initrd_bak
>  +	local action=$1
>  +
>  +	default_initrd="${KDUMP_BOOTDIR}/initramfs-${kdump_kver}.img"
>  +	default_initrd_bak="${KDUMP_BOOTDIR}/.initramfs-${kdump_kver}.img.default"
Hari,

$kdump_kver is the kdump kernel version, it may be different with the
default kernel version. Acording to my understanding the default initrd should use
the normal boot kernel version like `uname -r`

>   
>  -	# Check if backup initrd is already present.
>  -	target_initrd_bak="$TARGET_INITRD.bak"
>  -	if [ ! -e $target_initrd_bak ];then
>  -		echo "Backing up $TARGET_INITRD"
>  -		cp $TARGET_INITRD $target_initrd_bak
>  +	if [[ $action != "restore" ]]; then
>  +		if [ ! -e $default_initrd_bak ]; then
>  +			echo "Backing up $default_initrd"
>  +			cp $default_initrd $default_initrd_bak
>  +		fi
>  +	else
>  +		# If a backup initrd exists, we must be switching back from
>  +		# fadump to kdump. Restore the original default initrd.
>  +		if [ -f $default_initrd_bak ];then
>  +			mv $default_initrd_bak $default_initrd
>  +			if [[ $? -eq 0 ]]; then
>  +				echo -n "Default initrd is restored as fadump mode "
>  +				echo "is disabled"
>  +				sync
>  +			fi
>  +		fi
>   	fi
>   }
>   
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Thanks
Dave