[PATCH v3] use dracut version get_persistent_dev and get_maj_min

[Dave Young]

We maintained kdump specific get persistent dev function, it is ready to
drop it.  Dracut upstream splitted dracut init stuff from dracut-functions.sh
so that we can source it.

OTOH, dracut now has a persistent_policy feature, for kdump when we dump to
raw disks we do not care the filesystem uuid and labels so we prefer to
search disk id instead. For raw disk set the persistent_policy before calling
get_persistent_dev ensure kdump logic still work.

Tested filesystem and raw dump in kvm guests.

[Xunlei: Also drop get_maj_min, dracut-functions.sh also has such a function.]

Signed-off-by: Dave Young <dyoung(a)redhat.com&gt;
---
 kdump-lib.sh |   26 --------------------------
 kdumpctl     |    8 +++++++-
 mkdumprd     |   22 ++++++----------------
 3 files changed, 13 insertions(+), 43 deletions(-)

--- kexec-tools.orig/kdump-lib.sh
+++ kexec-tools/kdump-lib.sh
@@ -88,32 +88,6 @@ to_dev_name() {
     echo $dev
 }
 
-kdump_get_persistent_dev() {
-    local i _tmp _dev _lookup_dirs
-
-    _dev=$(udevadm info --query=name --name="$1" 2>/dev/null)
-    [ -z "$_dev" ] && {
-        perror_exit "Kernel dev name of $1 is not found."
-    }
-
-    if [[ $2 = "raw" ]];then
-	_lookup_dirs="/dev/mapper/* /dev/disk/by-id/*"
-    else
-	_lookup_dirs="/dev/mapper/* /dev/disk/by-uuid/* /dev/disk/by-id/*"
-    fi
-
-    for i in $_lookup_dirs; do
-        _tmp=$(udevadm info --query=name --name="$i" 2>/dev/null)
-        if [ "$_tmp" = "$_dev" ]; then
-            echo $i
-            return
-        fi
-    done
-
-    perror "WARNING: Persistent device name of $1 not found. Using $1 as dump target
name"
-    echo $1
-}
-
 get_user_configured_dump_disk()
 {
     local _target
--- kexec-tools.orig/kdumpctl
+++ kexec-tools/kdumpctl
@@ -19,6 +19,8 @@ FADUMP_REGISTER_SYS_NODE="/sys/kernel/fa
 DEFAULT_DUMP_MODE="kdump"
 image_time=0
 
+[[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut
+. $dracutbasedir/dracut-functions.sh
 . /lib/kdump/kdump-lib.sh
 
 standard_kexec_args="-p"
@@ -432,7 +434,11 @@ check_dump_fs_modified()
 	if [[ $(expr substr $_new_fstype 1 3) = "nfs" ]];then
 		_new_dev=$_target
 	else
-		_new_dev=$(kdump_get_persistent_dev $_target $_new_fstype)
+		_new_dev=$(get_persistent_dev $_target)
+		if [ -z "$_new_dev" ]; then
+			echo "Get persistent device name failed"
+			return 2
+		fi
 	fi
 
         if ! findmnt $_target >/dev/null; then
--- kexec-tools.orig/mkdumprd
+++ kexec-tools/mkdumprd
@@ -6,6 +6,8 @@
 # Written by Cong Wang <amwang(a)redhat.com&gt;
 #
 
+[[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut
+. $dracutbasedir/dracut-functions.sh
 . /lib/kdump/kdump-lib.sh
 export IN_KDUMP=1
 
@@ -127,8 +129,8 @@ to_mount() {
     _mntopts="$_target $_fstype $_options"
     #for non-nfs _dev converting to use udev persistent name
     if [ -b "$_source" ]; then
-        _pdev="$(kdump_get_persistent_dev $_source $_fstype)"
-        if [ $? -ne 0 ]; then
+        _pdev="$(get_persistent_dev $_source)"
+        if [ -z "$_pdev" ]; then
             return 1
         fi
 
@@ -257,18 +259,6 @@ add_mount() {
     fi
 }
 
-# get_maj_min <device>
-# Prints the major and minor of a device node.
-# Example:
-# $ get_maj_min /dev/sda2
-# 8:2
-get_maj_min() {
-    local _dev
-    _dev=$(stat -L -c '$((0x%t)):$((0x%T))' "$1" 2>/dev/null)
-    _dev=$(eval "echo $_dev")
-    echo $_dev
-}
-
 # ugly workaround for the lvm design
 # There is no volume group device,
 # so, there are no slave devices for volume groups.
@@ -532,8 +522,8 @@ do
         dd if=$config_val count=1 of=/dev/null > /dev/null 2>&1 || {
             perror_exit "Bad raw disk $config_val"
         }
-        _praw=$(kdump_get_persistent_dev $config_val "raw")
-        if [ $? -ne 0 ]; then
+        _praw=$(persistent_policy="by-id" get_persistent_dev $config_val)
+        if [ -z "$_praw" ]; then
             exit 1
         fi
         add_dracut_arg "--device" "$_praw"