[OE-core] [PATCH] systemd-udev: Add systemd-mount to mount.sh

[Hongzhi, Song]

ping.

// hongzhi

On 2018年03月06日 18:54, Hongzhi.Song wrote:
> Issue: mkfs.ext4 </dev/storage-device-name> fails, prompting that the device
> is in use by the system. But there is no mounted infomation in /proc/mounts.
>
> Reproduce: Be sure that there is storage device connected to you machine.
>
> 	Boot the machine.
> 	root at intel-x86-64:~# mkfs.ext4 /dev/mmcblk0p1
> 	mke2fs 1.43.5 (04-Aug-2017)
> 	/dev/mmcblk0p1 contains a ext2 file system
> 	last mounted on / on Tue Jan 9 05:24:36 2018
> 	Proceed anyway? (y,N) y
> 	/dev/mmcblk0p1 is apparently in use by the system; will not make a filesystem here!
>
> 	root at intel-x86-64:~# fdisk -l
> 	...
> 	Disk /dev/mmcblk0: 58.2 GiB, 62537072640 bytes, 122142720 sectors
> 	Units: sectors of 1 * 512 = 512 bytes
> 	Sector size (logical/physical): 512 bytes / 512 bytes
> 	I/O size (minimum/optimal): 512 bytes / 512 bytes
> 	Disklabel type: dos
> 	Disk identifier: 0xe62c8fcc
>
> 	Device Boot Start End Sectors Size Id Type
> 	/dev/mmcblk0p1 2048 122142719 122140672 58.2G 83 Linux
> 	...
>
> 	root at intel-x86-64:~#cat /proc/mounts
> 	...
> 	cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
> 	mqueue /dev/mqueue mqueue rw,relatime 0 0
> 	debugfs /sys/kernel/debug debugfs rw,relatime 0 0
> 	tmpfs /tmp tmpfs rw,nosuid,nodev 0 0
> 	hugetlbfs /dev/hugepages hugetlbfs rw,relatime 0 0
> 	tmpfs /var/volatile tmpfs rw,relatime 0 0
> 	tmpfs /run/user/0 tmpfs rw,nosuid,nodev,relatime,size=688048k,mode=700 0 0
>
> Description:
> 	If linux uses systemd as init, systemd-udevd.service sets MountFlags=slave,
> 	which is essentially a sandboxing setting: it detaches mount() operations
> 	done within the service from the rest of the system. This means that,
> 	outside of namespace of systemd-udev, we can not access device mounted by
> 	udev and some operation will be failed.(e.g. mkfs.ext4 /dev/sda1).
>
> 	Current automount.rules and mount.sh created for sysvinit is unable to solve
> 	above problems.
>
> 	This patch adds systemd-mount in /etc/udev/script/mount.sh. The tool
> 	recommended by systemd upstream generally is the best way in particular in
> 	embedded applications to deal with hotpluggable media. Systemd-mount request
> 	the mount operation to be executed by PID 1, and hence outside of the mount
> 	context of udev.
>
> Signed-off-by: Hongzhi.Song <hongzhi.song at windriver.com>
> ---
>   meta/recipes-core/udev/udev-extraconf/mount.sh | 61 +++++++++++++++++++++++---
>   1 file changed, 56 insertions(+), 5 deletions(-)
>
> diff --git a/meta/recipes-core/udev/udev-extraconf/mount.sh b/meta/recipes-core/udev/udev-extraconf/mount.sh
> index d760328..2fa2925 100644
> --- a/meta/recipes-core/udev/udev-extraconf/mount.sh
> +++ b/meta/recipes-core/udev/udev-extraconf/mount.sh
> @@ -5,9 +5,28 @@
>   # Attempt to mount any added block devices and umount any removed devices
>   
>   
> -MOUNT="/bin/mount"
> +BASE_INIT="`readlink "/sbin/init"`"
> +INIT_SYSTEMD="/lib/systemd/systemd"
> +
> +if [ "x$BASE_INIT" = "x$INIT_SYSTEMD" ];then
> +	# systemd as init uses systemd-mount to mount block devices
> +        MOUNT="/usr/bin/systemd-mount"
> +        UMOUNT="/usr/bin/systemd-umount"
> +
> +        if [ -x $MOUNT ] && [ -x $UMOUNT ];
> +        then
> +                logger "Using systemd-mount to finish mount"
> +        else
> +                logger "Linux init is using systemd, so please install systemd-mount to finish mount"
> +		exit 1
> +        fi
> +else
> +        MOUNT="/bin/mount"
> +        UMOUNT="/bin/umount"
> +fi
> +
>   PMOUNT="/usr/bin/pmount"
> -UMOUNT="/bin/umount"
> +
>   for line in `grep -h -v ^# /etc/udev/mount.blacklist /etc/udev/mount.blacklist.d/*`
>   do
>   	if [ ` expr match "$DEVNAME" "$line" ` -gt 0 ];
> @@ -17,6 +36,34 @@ do
>   	fi
>   done
>   
> +automount_systemd() {
> +        name="`basename "$DEVNAME"`"
> +
> +        ! test -d "/run/media/$name" && mkdir -p "/run/media/$name"
> +
> +        MOUNT="$MOUNT -o silent"
> +
> +        # If filesystemtype 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
> +                #logger "mount.sh/automount" "$MOUNT -t auto $DEVNAME \"/run/media/$name\" failed!"
> +                rm_dir "/run/media/$name"
> +        else
> +                logger "mount.sh/automount" "Auto-mount of [/run/media/$name] successful"
> +                touch "/tmp/.automount-$name"
> +        fi
> +}
> +
>   automount() {	
>   	name="`basename "$DEVNAME"`"
>   
> @@ -72,9 +119,13 @@ if [ "$ACTION" = "add" ] && [ -n "$DEVNAME" ] && [ -n "$ID_FS_TYPE" -o "$media_t
>   	# 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
> -	fi
> +        if expr $MAJOR "*" 256 + $MINOR != `stat -c %d /`; then
> +                if [ "`basename $MOUNT`" = "systemd-mount" ];then
> +                        grep -q "^$DEVNAME " /proc/mounts || automount_systemd
> +                else
> +                        grep -q "^$DEVNAME " /proc/mounts || automount
> +                fi
> +        fi
>   fi
>   
>