update_engine: Add Squashfs (phase 1)

Currently the Android container in CrOS is a Squashfs image (around
500MB) and the update engine treats it as one single file. This patch
uses -map flag in 'unsquashfs' to get the location of files inside the
Squashfs image. and creates a list of files that can be used in payload
generator to create a delta. This patch adds support for both Squashfs
file system and its appropriate unittests. However, we do not activate
it in this patch, further patches will activate and use it in the
payload generator.

BUG=chromium:767120
TEST=cros_workon_make --board=amd64-generic --test update_engine;
CQ-DEPEND=CL:650518,CL:686034

Change-Id: I02179727cd736661704d0ca2d9f881754b332b36
Reviewed-on: https://chromium-review.googlesource.com/636105
Commit-Ready: Amin Hassani <ahassani@chromium.org>
Tested-by: Amin Hassani <ahassani@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>

1 files changed, 29 insertions, 16 deletions

diff --git a/sample_images/generate_images.sh b/sample_images/generate_images.sh
index 6a0d1ea0..8478682e 100755
--- a/sample_images/generate_images.sh
+++ b/sample_images/generate_images.sh
@@ -26,12 +26,15 @@ set -e
 # cleanup <path>
 # Unmount and remove the mountpoint <path>
 cleanup() {
-  if ! sudo umount "$1" 2>/dev/null; then
-    if mountpoint -q "$1"; then
-      sync && sudo umount "$1"
+  local path="$1"
+  if ! sudo umount "${path}" 2>/dev/null; then
+    if mountpoint -q "${path}"; then
+      sync && sudo umount "${path}"
     fi
   fi
-  rmdir "$1"
+  if [ -n "${path}" ]; then
+    sudo rm -rf "${path}"
+  fi
 }
 
 # add_files_default <mntdir> <block_size>
@@ -203,10 +206,11 @@ EOF
 # generate_fs <filename> <kind> <size> [block_size] [block_groups]
 generate_fs() {
   local filename="$1"
-  local kind="$2"
-  local size="$3"
-  local block_size="${4:-4096}"
-  local block_groups="${5:-}"
+  local type="$2"
+  local kind="$3"
+  local size="$4"
+  local block_size="${5:-4096}"
+  local block_groups="${6:-}"
 
   local mkfs_opts=( -q -F -b "${block_size}" -L "ROOT-TEST" -t ext2 )
   if [[ -n "${block_groups}" ]]; then
@@ -215,16 +219,17 @@ generate_fs() {
 
   local mntdir=$(mktemp --tmpdir -d generate_ext2.XXXXXX)
   trap 'cleanup "${mntdir}"; rm -f "${filename}"' INT TERM EXIT
-
   # Cleanup old image.
   if [[ -e "${filename}" ]]; then
     rm -f "${filename}"
   fi
-  truncate --size="${size}" "${filename}"
 
-  mkfs.ext2 "${mkfs_opts[@]}" "${filename}"
-  sudo mount "${filename}" "${mntdir}" -o loop
+  if [[ "${type}" == "ext2" ]]; then
+    truncate --size="${size}" "${filename}"
 
+    mkfs.ext2 "${mkfs_opts[@]}" "${filename}"
+    sudo mount "${filename}" "${mntdir}" -o loop
+  fi
   case "${kind}" in
     unittest)
       add_files_ue_settings "${mntdir}" "${block_size}"
@@ -237,6 +242,10 @@ generate_fs() {
       ;;
   esac
 
+  if [[ "${type}" == "sqfs" ]]; then
+    mksquashfs "${mntdir}" "${filename}"
+  fi
+
   cleanup "${mntdir}"
   trap - INT TERM EXIT
 }
@@ -253,10 +262,14 @@ generate_image() {
 
 main() {
   # Add more sample images here.
-  generate_image disk_ext2_1k default $((1024 * 1024)) 1024
-  generate_image disk_ext2_4k default $((1024 * 4096)) 4096
-  generate_image disk_ext2_4k_empty empty $((1024 * 4096)) 4096
-  generate_image disk_ext2_unittest unittest $((1024 * 4096)) 4096
+  generate_image disk_ext2_1k ext2 default $((1024 * 1024)) 1024
+  generate_image disk_ext2_4k ext2 default $((1024 * 4096)) 4096
+  generate_image disk_ext2_4k_empty ext2 empty $((1024 * 4096)) 4096
+  generate_image disk_ext2_unittest ext2 unittest $((1024 * 4096)) 4096
+
+  # Add squashfs sample images.
+  generate_image disk_sqfs_empty sqfs empty $((1024 * 4096)) 4096
+  generate_image disk_sqfs_default sqfs default $((1024 * 4096)) 4096
 
   # Generate the tarball and delete temporary images.
   echo "Packing tar file sample_images.tar.bz2"