[OE-core] [PATCH v2 4/4] busybox-mdev: Support automatic mounting of block devices

[Khem Raj]

> On Dec 18, 2014, at 6:17 AM, Mike Looijmans <mike.looijmans at topic.nl> wrote:
> 
> Upon inserting a USB stick or similar device, mdev will run
> an automounter script that mounts valid partitions on
> /media/<device>. The script first checks /etc/fstab entries
> so that mounting on UUID or LABEL or using custom mount options
> is still possible. If /etc/fstab does not contain particular
> mount options, the script will create (and remove) the mountpoint
> automatically.
> The script also supports full disk partitions (devices without
> partition table).
> 
> The following environments can be set in /etc/default/mdev:
> MDEV_AUTOMOUNT=n (Disables automounting completely)
> MDEV_AUTOMOUNT_ROOT=/media (Change the mount root location)
> 
> Automatic mounting for a particular device can be disabled by
> creating a file "/dev/<device>.nomount". This is helpful in
> scripts that create partitions for example, and want to perform
> specific actions which require the device to remain unmounted.
> 
> A more complex variation (using LABEL based mounts) on this script
> has been in use in OpenPLi for many years now, and I've used this
> one on many projects already, so it's about time to push this to
> mainline.
> 
> Signed-off-by: Mike Looijmans <mike.looijmans at topic.nl>
> ---
> meta/recipes-core/busybox/busybox.inc         |    1 +
> meta/recipes-core/busybox/busybox_1.22.1.bb   |    1 +
> meta/recipes-core/busybox/busybox_git.bb      |    1 +
> meta/recipes-core/busybox/files/mdev-mount.sh |   63 +++++++++++++++++++++++++
> meta/recipes-core/busybox/files/mdev.conf     |    3 ++
> 5 files changed, 69 insertions(+)
> create mode 100644 meta/recipes-core/busybox/files/mdev-mount.sh
> 
> diff --git a/meta/recipes-core/busybox/busybox.inc b/meta/recipes-core/busybox/busybox.inc
> index deb2ee4..0769d92 100644
> --- a/meta/recipes-core/busybox/busybox.inc
> +++ b/meta/recipes-core/busybox/busybox.inc
> @@ -270,6 +270,7 @@ do_install () {
>                        install -m 644 ${WORKDIR}/mdev.conf ${D}${sysconfdir}/mdev.conf
>                        install -d ${D}${sysconfdir}/mdev
>                        install -m 0755 ${WORKDIR}/find-touchscreen.sh ${D}${sysconfdir}/mdev
> +                       install -m 0755 ${WORKDIR}/mdev-mount.sh ${D}${sysconfdir}/mdev
>                fi
> 	fi
> 
> diff --git a/meta/recipes-core/busybox/busybox_1.22.1.bb b/meta/recipes-core/busybox/busybox_1.22.1.bb
> index 82f7f68..f379bb6 100644
> --- a/meta/recipes-core/busybox/busybox_1.22.1.bb
> +++ b/meta/recipes-core/busybox/busybox_1.22.1.bb
> @@ -20,6 +20,7 @@ SRC_URI = "http://www.busybox.net/downloads/busybox-${PV}.tar.bz2;name=tarball \
>            file://busybox-syslog.default \
>            file://mdev \
>            file://mdev.conf \
> +           file://mdev-mount.sh \
>            file://umount.busybox \
>            file://defconfig \
>            file://busybox-syslog.service.in \
> diff --git a/meta/recipes-core/busybox/busybox_git.bb b/meta/recipes-core/busybox/busybox_git.bb
> index f2cc119..f91b552 100644
> --- a/meta/recipes-core/busybox/busybox_git.bb
> +++ b/meta/recipes-core/busybox/busybox_git.bb
> @@ -24,6 +24,7 @@ SRC_URI = "git://busybox.net/busybox.git \
>            file://busybox-syslog.default \
>            file://mdev \
>            file://mdev.conf \
> +           file://mdev-mount.sh \
>            file://umount.busybox \
>            file://defconfig \
>            file://busybox-syslog.service.in \
> diff --git a/meta/recipes-core/busybox/files/mdev-mount.sh b/meta/recipes-core/busybox/files/mdev-mount.sh
> new file mode 100644
> index 0000000..d5d66d6
> --- /dev/null
> +++ b/meta/recipes-core/busybox/files/mdev-mount.sh
> @@ -0,0 +1,63 @@
> +#!/bin/sh
> +MDEV_AUTOMOUNT=y
> +MDEV_AUTOMOUNT_ROOT=/run/media
> +[ -f /etc/default/mdev ] && . /etc/default/mdev
> +if [ "${MDEV_AUTOMOUNT}" = "n" ] ; then
> +	exit 0
> +fi
> +
> +case "$ACTION" in
> +	add|"")
> +		ACTION="add"
> +		# check if already mounted
> +		if grep -q "^/dev/${MDEV} " /proc/mounts ; then
> +			# Already mounted
> +			exit 0
> +		fi
> +		DEVBASE=`expr substr $MDEV 1 3`
> +		if [ "${DEVBASE}" == "mmc" ] ; then
> +			DEVBASE=`expr substr $MDEV 1 7`
> +		fi
> +		# check for "please don't mount it" file
> +		if [ -f "/dev/nomount.${DEVBASE}" ] ; then
> +			# blocked
> +			exit 0
> +		fi
> +		# check for full-disk partition
> +		if [ "${DEVBASE}" == "${MDEV}" ] ; then

bashism, get rid of it.

> +			if [ -d /sys/block/${DEVBASE}/${DEVBASE}*1 ] ; then
> +				# Partition detected, just quit
> +				exit 0
> +			fi
> +			if [ ! -f /sys/block/${DEVBASE}/size ] ; then
> +				# No size at all
> +				exit 0
> +			fi
> +			if [ `cat /sys/block/${DEVBASE}/size` == 0 ] ; then
> +				# empty device, bail out
> +				exit 0
> +			fi
> +		fi
> +		# first allow fstab to determine the mountpoint
> +		if ! mount /dev/$MDEV > /dev/null 2>&1
> +		then
> +			MOUNTPOINT="${MDEV_AUTOMOUNT_ROOT}/$MDEV"
> +			mkdir "$MOUNTPOINT"
> +			mount -t auto /dev/$MDEV "$MOUNTPOINT"
> +		fi
> +		;;
> +	remove)
> +		MOUNTPOINT=`grep "^/dev/$MDEV\s" /proc/mounts | cut -d' ' -f 2`
> +		if [ ! -z "$MOUNTPOINT" ]
> +		then
> +			umount "$MOUNTPOINT"
> +			rmdir "$MOUNTPOINT"
> +		else
> +			umount /dev/$MDEV
> +		fi
> +		;;
> +	*)
> +		# Unexpected keyword
> +		exit 1
> +		;;
> +esac
> diff --git a/meta/recipes-core/busybox/files/mdev.conf b/meta/recipes-core/busybox/files/mdev.conf
> index 6dfd161..17e93da 100644
> --- a/meta/recipes-core/busybox/files/mdev.conf
> +++ b/meta/recipes-core/busybox/files/mdev.conf
> @@ -37,3 +37,6 @@ input/mice 0:0 0660
> input/mouse.* 0:0 0660
> 
> tun[0-9]* 0:0 0660 =net/
> +
> +[hs]d[a-z][0-9]? 0:0 660 */etc/mdev/mdev-mount.sh
> +mmcblk[0-9].* 0:0 660 */etc/mdev/mdev-mount.sh
> -- 
> 1.7.9.5
> 
> -- 
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