kdump-lib.sh: fix improper get_block_dump_target()

Resolves: bz1451717
https://bugzilla.redhat.com/1451717

This patch improves get_block_dump_target as follows:
-Consider block device in the special "--dracut-args --mount ..."
 in get_user_configured_dump_disk().
-Consider save path instead of root fs in get_block_dump_target(),
 and move it into kdump-lib.sh because we will have another user
 in the following patch.
-For nfs/ssh dumping, there is no need to check the root device.
-Move get_save_path into kdump-lib.sh.

After this patch, get_block_dump_target() can always return the
correct block dump target specified.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Acked-by: Dave Young <dyoung@redhat.com>

kdump-lib.sh

@@ -44,12 +44,6 @@ is_fs_dump_target()
     egrep -q "^ext[234]|^xfs|^btrfs|^minix" /etc/kdump.conf
 }
 
-is_user_configured_dump_target()
-{
-    return $(is_mount_in_dracut_args || is_ssh_dump_target || is_nfs_dump_target || \
-             is_raw_dump_target || is_fs_dump_target)
-}
-
 strip_comments()
 {
     echo $@ | sed -e 's/\(.*\)#.*/\1/'
@@ -88,18 +82,21 @@ to_dev_name() {
     echo $dev
 }
 
+is_user_configured_dump_target()
+{
+    return $(is_mount_in_dracut_args || is_ssh_dump_target || is_nfs_dump_target || \
+             is_raw_dump_target || is_fs_dump_target)
+}
+
 get_user_configured_dump_disk()
 {
     local _target
 
-    if is_ssh_dump_target || is_nfs_dump_target; then
-        return
-    fi
-
     _target=$(egrep "^ext[234]|^xfs|^btrfs|^minix|^raw" /etc/kdump.conf 2>/dev/null |awk '{print $2}')
-    [ -n "$_target" ] && echo $_target
+    [ -n "$_target" ] && echo $_target && return
 
-    return
+    _target=$(get_dracut_args_target "$(grep "^dracut_args .*\-\-mount" /etc/kdump.conf)")
+    [ -b "$_target" ] && echo $_target
 }
 
 get_root_fs_device()
@@ -111,6 +108,33 @@ get_root_fs_device()
     return
 }
 
+get_save_path()
+{
+	local _save_path=$(grep "^path" /etc/kdump.conf|awk '{print $2}')
+	if [ -z "$_save_path" ]; then
+		_save_path=$DEFAULT_PATH
+	fi
+
+	echo $_save_path
+}
+
+get_block_dump_target()
+{
+    local _target _path
+
+    if is_ssh_dump_target || is_nfs_dump_target; then
+        return
+    fi
+
+    _target=$(get_user_configured_dump_disk)
+    [ -n "$_target" ] && echo $(to_dev_name $_target) && return
+
+    # Get block device name from local save path
+    _path=$(get_save_path)
+    _target=$(get_target_from_path $_path)
+    [ -b "$_target" ] && echo $(to_dev_name $_target)
+}
+
 # findmnt uses the option "-v, --nofsroot" to exclusive the [/dir]
 # in the SOURCE column for bind-mounts, then if $_mntpoint equals to
 # $_mntpoint_nofsroot, the mountpoint is not bind mounted directory.

kdumpctl

@@ -978,16 +978,6 @@ save_raw()
 	return 0
 }
 
-get_save_path()
-{
-	local _save_path=$(grep "^path" /etc/kdump.conf|awk '{print $2}')
-	if [ -z "$_save_path" ]; then
-		_save_path="/var/crash"
-	fi
-
-	echo $_save_path
-}
-
 is_dump_target_configured()
 {
 	local _target

mkdumprd

@@ -250,19 +250,6 @@ add_mount() {
     add_dracut_mount "$_mnt"
 }
 
-get_block_dump_target()
-{
-    local _target
-
-
-    _target=$(get_user_configured_dump_disk)
-    [ -n "$_target" ] && echo $(to_dev_name $_target) && return
-
-    #get rootfs device name
-    _target=$(get_root_fs_device)
-    [ -b "$_target" ] && echo $(to_dev_name $_target)
-}
-
 #handle the case user does not specify the dump target explicitly
 handle_default_dump_target()
 {