add vfat remounting script (#28)

* add new mounting script

* update makefile

Author: master-hax

Makefile

@@ -14,6 +14,7 @@ DEVICE_TEMP_DIRECTORY := /data/local/tmp
 
 ALL_SCRIPTS := \
 scripts/mount_ext4.sh \
+scripts/remount_vfat.sh \
 scripts/unmount.sh \
 scripts/find_device.sh \
 scripts/show_devices.sh \
@@ -29,10 +30,10 @@ mobile-install: pixel-backup-gang-$(PBG_VERSION).tar.gz
 	# copy the tarball containing scripts
 	$(HOST_ADB_COMMAND) push ./pixel-backup-gang-$(PBG_VERSION).tar.gz $(DEVICE_TEMP_DIRECTORY)
 	# extract the scripts
-	$(HOST_ADB_COMMAND) shell /sbin/su --command 'tar -xvf $(DEVICE_TEMP_DIRECTORY)/pixel-backup-gang-$(PBG_VERSION).tar.gz -C $(DEVICE_INSTALL_DIRECTORY)'
+	$(HOST_ADB_COMMAND) shell su --command 'tar -xvf $(DEVICE_TEMP_DIRECTORY)/pixel-backup-gang-$(PBG_VERSION).tar.gz -C $(DEVICE_INSTALL_DIRECTORY)'
 	# make the scripts executable
-	$(HOST_ADB_COMMAND) shell /sbin/su --command 'chmod +x $(DEVICE_INSTALL_DIRECTORY)/pixel-backup-gang-$(PBG_VERSION)/*.sh'
-	# done, installed scripts to $(DEVICE_INSTALL_DIRECTORY)/pixel-backup-gang-$(PBG_VERSION)
+	$(HOST_ADB_COMMAND) shell su --command 'chmod +x $(DEVICE_INSTALL_DIRECTORY)/pixel-backup-gang/*.sh'
+	# done, installed scripts to $(DEVICE_INSTALL_DIRECTORY)/pixel-backup-gang
 
 .PHONY: clean
 clean:

scripts/remount_vfat.sh

@@ -0,0 +1,45 @@
+#!/bin/sh -e
+
+################################################################################
+# Description: remounts /the_binding in the specified mounted vfat folder to the internal storage
+# Author: Vivek Revankar <vivek@master-hax.com>
+# Usage: ./remount_vfat.sh <DIRECTORY_PATH>
+# Example: ./remount_vfat.sh /mnt/media_rw/2IDK-11F4
+################################################################################
+
+if [ "$(readlink /proc/self/ns/mnt)" != "$(readlink /proc/1/ns/mnt)" ]; then
+  echo "not running in global mount namespace, try elevating first"
+  exit 1
+fi
+
+if [ "$#" -ne 1 ]; then
+  echo "Usage: $0 /mnt/media_rw/<label>" >&2
+  exit 1
+fi
+
+mounted_drive_path=$1
+if [ ! -e "$mounted_drive_path" ]; then
+  echo "directory was not found"
+  exit 1
+fi
+if [ ! -d "$mounted_drive_path" ]; then
+  echo "path was not a directory"
+  exit 1
+fi
+
+fs_type=$(stat -f -c %T $mounted_drive_path)
+if [ "$fs_type" != "msdos" ]; then
+    echo "detected filesystem type was not 'msdos', found $fs_type"
+    exit 1
+fi
+
+drive_binding_dir="$mounted_drive_path/the_binding"
+internal_binding_dir="/mnt/runtime/write/emulated/0/the_binding"
+mkdir -p -v "$drive_binding_dir"
+mkdir -p -v "$internal_binding_dir"
+mount \
+-t sdcardfs \
+-o nosuid,nodev,noexec,noatime,gid=9997 \
+"$drive_binding_dir" "$internal_binding_dir"
+
+echo "vfat drive remounted succesfully"