From 4732d5d0c39da39f2098c3e19cb5f7dcd7d429bb Mon Sep 17 00:00:00 2001
From: Hung-Te Lin <hungte@chromium.org>
Date: Mon, 4 Oct 2010 11:01:11 +0800
Subject: [PATCH] crosutils: Improve dd in image_to_usb.sh

1. add oflags=sync to allow interrupting dd without hanging system I/O for a long time
   (since bs=4M, the speed is almost the same)
2. use pv to provide progress report if available.
   (add pv into host-depends in http://codereview.chromium.org/3608004)

BUG=none
TEST=manually:
1. install pv in chroot, then execute image_to_usb.sh --to /dev/sdX and verified there's progress bar
2. ctrl-c to break the dd process and verified it can stop immediately
3. remove pv from chroot, then execute image_to_usb.sh and verify that it still works

Change-Id: I62fc373a4feee6d7e61897325d9e1e6d84a74d63

Review URL: http://codereview.chromium.org/3581007
---
 image_to_usb.sh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/image_to_usb.sh b/image_to_usb.sh
index f40e57a4a3..81a3ab58dd 100755
--- a/image_to_usb.sh
+++ b/image_to_usb.sh
@@ -236,7 +236,11 @@ then
 
   if [ ${FLAGS_install} -ne ${FLAGS_TRUE} ]; then
     echo "Copying ${SRC_IMAGE} to ${FLAGS_to}..."
-    sudo dd if="${SRC_IMAGE}" of="${FLAGS_to}" bs=4M
+    if type pv >/dev/null 2>&1; then
+      sudo pv -ptre "${SRC_IMAGE}" | sudo dd of="${FLAGS_to}" bs=4M oflag=sync
+    else
+      sudo dd if="${SRC_IMAGE}" of="${FLAGS_to}" bs=4M oflag=sync
+    fi
     sync
   else
     if [ ${INSIDE_CHROOT} -ne 1 ]; then