[OE-core] [oe-core][PATCH v4 1/3] udev-extraconf/mount.sh: add support to systemd

[Hongzhi.Song]

Udev-extraconf works correctly with sysvinit in the aspect of automounting
block devices. But it has a serious problem in case of systemd. Block devices
automounted by udev is unaccessible to host space(out of udevd's private
namespace). For example, we cannot format those block devices.

e.g.
    root at qemux86:~# mkfs.ext4 /dev/sda1
    mke2fs 1.43.8
    /dev/sda1 contains a ext4 file system
    last mounted on Tue Apr
    Proceed anyway? (y,N) y
    /dev/sda1 is apparently in use by the system; will not make a filesystem here!

Other distributions has no such problem, because they use a series of rules to
manager block devices. Different types of block devices match different rules.
But udev-extraconf just use one rule, automount.rules, which results in this
problem.

The 'systemd-mount' command is recommended by the systemd community to solve such
problems.

This patch makes use of 'systemd-mount' to solve the above problem.

[YOCTO #12644]

Signed-off-by: Hongzhi.Song <hongzhi.song at windriver.com>
---
 meta/recipes-core/udev/udev-extraconf/mount.sh | 55 +++++++++++++++++++++++---
 1 file changed, 50 insertions(+), 5 deletions(-)

diff --git a/meta/recipes-core/udev/udev-extraconf/mount.sh b/meta/recipes-core/udev/udev-extraconf/mount.sh
index d760328a09..3a72c455e0 100644
--- a/meta/recipes-core/udev/udev-extraconf/mount.sh
+++ b/meta/recipes-core/udev/udev-extraconf/mount.sh
@@ -4,10 +4,26 @@
 #
 # Attempt to mount any added block devices and umount any removed devices
 
+BASE_INIT="`readlink "/sbin/init"`"
+INIT_SYSTEMD="/lib/systemd/systemd"
+
+if [ "x$BASE_INIT" = "x$INIT_SYSTEMD" ];then
+        MOUNT="/usr/bin/systemd-mount"
+        UMOUNT="/usr/bin/systemd-umount"
+
+        if [ -x $MOUNT ] && [ -x $UMOUNT ];
+        then
+                logger "Using systemd-mount to finish mount"
+        else
+                logger "Linux init is using systemd, so please install systemd-mount to finish mount"
+        fi
+else
+        MOUNT="/bin/mount"
+        UMOUNT="/bin/umount"
+fi
 
-MOUNT="/bin/mount"
 PMOUNT="/usr/bin/pmount"
-UMOUNT="/bin/umount"
+
 for line in `grep -h -v ^# /etc/udev/mount.blacklist /etc/udev/mount.blacklist.d/*`
 do
 	if [ ` expr match "$DEVNAME" "$line" ` -gt 0 ];
@@ -17,6 +33,33 @@ do
 	fi
 done
 
+automount_systemd() {
+	name="`basename "$DEVNAME"`"
+
+        ! test -d "/run/media/$name" && mkdir -p "/run/media/$name"
+        # Silent util-linux's version of mounting auto
+        MOUNT="$MOUNT -o silent"
+        
+        # If filesystem type is vfat, change the ownership group to 'disk', and
+        # grant it with  w/r/x permissions.
+        case $ID_FS_TYPE in
+        vfat|fat)
+                MOUNT="$MOUNT -o umask=007,gid=`awk -F':' '/^disk/{print $3}' /etc/group`"
+                ;;
+        # TODO
+        *)
+                ;;
+        esac
+
+        if ! $MOUNT --no-block -t auto $DEVNAME "/run/media/$name"
+        then
+                rm_dir "/run/media/$name"
+        else
+                logger "mount.sh/automount" "systemd-mount of [/run/media/$name] successful"
+                touch "/tmp/.automount-$name"
+        fi
+}
+
 automount() {	
 	name="`basename "$DEVNAME"`"
 
@@ -61,19 +104,21 @@ rm_dir() {
 # No ID_FS_TYPE for cdrom device, yet it should be mounted
 name="`basename "$DEVNAME"`"
 [ -e /sys/block/$name/device/media ] && media_type=`cat /sys/block/$name/device/media`
-
 if [ "$ACTION" = "add" ] && [ -n "$DEVNAME" ] && [ -n "$ID_FS_TYPE" -o "$media_type" = "cdrom" ]; then
 	if [ -x "$PMOUNT" ]; then
 		$PMOUNT $DEVNAME 2> /dev/null
 	elif [ -x $MOUNT ]; then
     		$MOUNT $DEVNAME 2> /dev/null
 	fi
-	
 	# If the device isn't mounted at this point, it isn't
 	# configured in fstab (note the root filesystem can show up as
 	# /dev/root in /proc/mounts, so check the device number too)
 	if expr $MAJOR "*" 256 + $MINOR != `stat -c %d /`; then
-		grep -q "^$DEVNAME " /proc/mounts || automount
+		if [ "`basename $MOUNT`" = "systemd-mount" ];then
+			grep -q "^$DEVNAME " /proc/mounts || automount_systemd
+		else
+			grep -q "^$DEVNAME " /proc/mounts || automount
+		fi
 	fi
 fi
 
-- 
2.11.0