From a81df76a064c23aeb297a3c56e7139fa30d10ca9 Mon Sep 17 00:00:00 2001
From: Bill Richardson <wfrichar@chromium.org>
Date: Fri, 9 Apr 2010 08:12:05 -0700
Subject: [PATCH] Replace "mount -o loop" with explict losetup use in
 build_image.

This fixes the loop device leak. The problem is that inside the chroot, we
have /etc/mtab as a symlink to /proc/mounts. That works most of the time,
but if you mount something using "-o loop", it isn't cleaned up correctly
when you umount it. To avoid that, we either have to replace the /etc/mtab
symlink with an empty file when we create the chroot, or we have to make
sure that we never execute a "mount -o loop" command from within the chroot.
If we use an empty /etc/mtab file, the builds work fine, but then we can't
see any mounted partitions that the host creates outside the chroot (such as
USB keys), which causes other problems. Bleah.

Review URL: http://codereview.chromium.org/1594020
---
 build_image | 30 ++++++++++++++++++++++--------
 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/build_image b/build_image
index e06071afa7..11548f74c3 100755
--- a/build_image
+++ b/build_image
@@ -73,6 +73,7 @@ BOARD_ROOT="${FLAGS_build_root}/${BOARD}"
 
 LOOP_DEV=
 STATEFUL_LOOP_DEV=
+ESP_LOOP_DEV=
 
 # What cross-build are we targeting?
 . "${BOARD_ROOT}/etc/make.conf.board_setup"
@@ -129,6 +130,8 @@ cleanup_stateful_fs_loop() {
 
 cleanup_esp_loop() {
   sudo umount "$ESP_DIR"
+  sleep 1
+  sudo losetup -d "$ESP_LOOP_DEV"
 }
 
 cleanup() {
@@ -143,7 +146,7 @@ cleanup() {
     cleanup_rootfs_loop
   fi
 
-  if [[ -n "$ESP_DIR" ]]; then
+  if [[ -n "$ESP_LOOP_DEV" ]]; then
     cleanup_esp_loop
   fi
 
@@ -358,19 +361,30 @@ ESP_IMG=${OUTPUT_DIR}/esp.image
 ESP_BLOCKS=16384
 /usr/sbin/mkfs.vfat -C ${OUTPUT_DIR}/esp.image ${ESP_BLOCKS}
 ESP_DIR=${OUTPUT_DIR}/esp
-mkdir -p ${ESP_DIR}
-sudo mount -o loop ${ESP_IMG} ${ESP_DIR}
-sudo mkdir -p ${ESP_DIR}/efi/boot
-sudo grub-mkimage -p /efi/boot -o ${ESP_DIR}/efi/boot/bootx64.efi \
+ESP_LOOP_DEV=$(sudo losetup -f)
+if [ -z "$ESP_LOOP_DEV" ] ; then
+  echo "No free loop device.  Free up a loop device or reboot.  exiting. "
+  exit 1
+fi
+mkdir -p "${ESP_DIR}"
+sudo losetup "${ESP_LOOP_DEV}" "${ESP_IMG}"
+sudo mount "${ESP_LOOP_DEV}" "${ESP_DIR}"
+sudo mkdir -p "${ESP_DIR}/efi/boot"
+sudo grub-mkimage -p /efi/boot -o "${ESP_DIR}/efi/boot/bootx64.efi" \
   part_gpt fat ext2 normal boot sh chain configfile linux
-sudo cp ${ROOT_FS_DIR}/boot/vmlinuz ${ESP_DIR}/efi/boot/vmlinuz
-cat <<EOF | sudo dd of=${ESP_DIR}/efi/boot/grub.cfg
+sudo cp "${ROOT_FS_DIR}/boot/vmlinuz" "${ESP_DIR}/efi/boot/vmlinuz"
+cat <<EOF | sudo dd of="${ESP_DIR}/efi/boot/grub.cfg"
 set timeout=2
 set default=0
 
-menuentry "32-bit serial" {
+menuentry "serial debug" {
   linux /efi/boot/vmlinuz earlyprintk=serial,ttyS0,115200 i915.modeset=0 console=ttyS0,115200 acpi=off init=/sbin/init boot=local rootwait root=/dev/sda3 ro noresume noswap loglevel=7
 }
+
+menuentry "normal" {
+  linux /efi/boot/vmlinuz quiet console=tty2 init=/sbin/init boot=local rootwait root=/dev/sda3 ro noresume noswap i915.modeset=1 loglevel=1
+}
+
 EOF
 
 # Enable dev mode on the target system and re-run ldconfig