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

["Peter A. Bigot" <pab@pabigot.com>]

On 01/01/2015 03:07 AM, Mike Looijmans wrote:
> On 01/01/2015 03:49 AM, Khem Raj wrote:
>>
>>> On Dec 18, 2014, at 6:17 AM, Mike Looijmans 
>>> <mike.looijmans@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@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.
>
> please explain?

From 
http://www.gnu.org/software/bash/manual/html_node/Bash-Conditional-Expressions.html:


string1 == string2
string1 = string2

     True if the strings are equal. ‘=’ should be used with the test 
command for POSIX conformance.


>
>>
>>> +            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
>>>
>>> -- 
>>> _______________________________________________
>>> Openembedded-core mailing list
>>> Openembedded-core@lists.openembedded.org
>>> http://lists.openembedded.org/mailman/listinfo/openembedded-core
>>
>
>