mjhjmtu

I'm developing an application on embedded linux kernel 2.6 powered device and Auto mounting and un-mounting process is not works correctly.

e.g. checking dmesg show kernel correctly determine insertion/removing of MMC device( I also can check this via /sys/blk/mmcblk0 ), after booting with MMC in slot ,MMC is initially mounted to /mnt/sdcard, but after removing MMC from slot,this directory is still valid with no data inside.

(please consider removing MMC without umount is one of my test cases and system must automatically unmount after a moment in this situation),Also after re-insertion of MMC ,it will not mount again(checking dmesg show kernel detect MMC insertion).

my Device use busybox mdev instead of udev and hotplug is enabled but mmcblk device handling is commented and I have no Idea how auto mounting is handled.
this is my hotplug code :

#!/bin/sh
#
# A generic /sbin/hotplug multiplexer program
#
# This script allows any program to be called when /sbin/hotplug is
# called. It will run any programs located in the default hotplug
# directory (currently /etc/hotplug.d/) that match up with the first
# argument that this script is called with. The matching is done by
# adding a directory name to the default directory and looking for any
# programs in that directory that are executable, and end in .hotplug
# (to allow backup programs to be live on safely.)
#
# For example, if /sbin/hotplug is called with the usb argument then
# this script will look in the /etc/hotplug.d/usb/ directory for any
# executable programs that end in .hotplug.
#
# After all programs in the argument directory are executed, the
# "default" directory is searched for any executable programs in it,
# that end in .hotplug. The default directory is currently
# /etc/hotplug.d/default/
#
# - Greg Kroah-Hartman
# May 1, 2003
#
# Released under the GPL Version 2.
#

DIR="/etc/hotplug.d"

#for I in "$DIR/$1/"*.hotplug "$DIR/"default/*.hotplug ; do
# if [ -f $I ]; then
# test -x $I && $I $1 ;
# fi
#done


#for debug
# if [ $DEVNAME ]; then
 # echo "===== USB hotplug event =====" >> $DEVNAME.txt
# else
 # echo "===== USB hotplug event =====" >> hotplug_event.txt
# fi
# echo "DEVPATH:$DEVPATH"
# echo "SUBSYSTEM:$SUBSYSTEM"
# echo "DEVTYPE:$DEVTYPE"
# echo "DEVNAME:$DEVNAME"
# echo "MAJOR:$MAJOR"
# echo "MINOR:$MINOR"
# echo "PRODUCT:$PRODUCT"
# echo "INTERFACE:$INTERFACE"
# echo "TYPE:$TYPE"
# echo "VENDOR_ID:$VENDOR_ID"
# echo "GUID:$GUID"
# echo "SPEFICIER_ID:$SPEFICIER_ID"
# echo "VERSION:$VERSION"
# echo "0:$0"
# echo "1:$1"
# echo "2:$2"
# echo "3:$3"



if [ $ACTION = add ]; then
 echo "== add =="
 if [ $SUBSYSTEM = net ]; then
 echo "== net =="
 if [ $INTERFACE = eth0 ]; then
 echo "== eth0 =="
 . /mnt/etc/enet.cfg
 ifconfig eth0 hw ether $ENETCFG_MAC
 ifconfig eth0 up
 fi
 elif [ $DEVTYPE = partition ]; then
 echo "== partition =="
 if [ $MAJOR = 8 ]; then
 echo "== USB storage =="
 mount /dev/$DEVNAME
 elif [ $MAJOR = 179 ]; then
 echo "== SD Card =="
 #mount /dev/mmcblk0p1
 fi
 fi
elif [ $ACTION = remove ]; then
 echo "== remove =="
 if [ $SUBSYSTEM = net ]; then
 echo "== net =="
 if [ $INTERFACE = eth0 ]; then
 echo "== eth0 =="
 # ifconfig eth0 down
 fi
 elif [ $DEVTYPE = partition ]; then
 echo "== partition =="
 if [ $MAJOR = 8 ]; then
 echo "== USB storage =="
 if [ $DEVNAME = sda1 ]; then
 umount /mnt/usb
 else
 umount /mnt/usb2
 fi
 elif [ $MAJOR = 179 ]; then
 echo "== SD Card =="
 #umount /mnt/sdcard
 fi
 fi
fi

exit 0

Do you have any idea how it handles auto mounting / un-mounting of MMC_block?
2- also when I un-commenting these section, problem is still remain.

EDIT:
Seems this is not related to the automount.sh script ,because I edit and checks many times and if this script be called it must correctly handled mount/unmount process of MMc,the only thing is remain is bug in the busybox version of mine(which is V1.10.11).