diff -Nru cloud-initramfs-tools-0.3ubuntu1/debian/changelog cloud-initramfs-tools-0.4ubuntu1/debian/changelog
--- cloud-initramfs-tools-0.3ubuntu1/debian/changelog	2011-12-20 18:24:47.000000000 +0000
+++ cloud-initramfs-tools-0.4ubuntu1/debian/changelog	2012-02-24 03:19:21.000000000 +0000
@@ -1,3 +1,10 @@
+cloud-initramfs-tools (0.4ubuntu1) precise; urgency=low
+
+  * growroot: run 'udevadm settle' before attempting growpart to
+    allow initial events to finish (LP: #937352)
+
+ -- Scott Moser <smoser@ubuntu.com>  Thu, 23 Feb 2012 22:19:20 -0500
+
 cloud-initramfs-tools (0.3ubuntu1) precise; urgency=low
 
   * growroot: unmount root before attempting to grow the root
diff -Nru cloud-initramfs-tools-0.3ubuntu1/growroot/scripts/local-bottom/growroot cloud-initramfs-tools-0.4ubuntu1/growroot/scripts/local-bottom/growroot
--- cloud-initramfs-tools-0.3ubuntu1/growroot/scripts/local-bottom/growroot	2011-12-20 17:57:16.000000000 +0000
+++ cloud-initramfs-tools-0.4ubuntu1/growroot/scripts/local-bottom/growroot	2012-02-24 03:19:05.000000000 +0000
@@ -65,6 +65,12 @@
 umount "${rootmnt}" ||
 	fail "failed to umount ${rootmnt}";
 
+# Wait for any of the initial udev events to finish
+# This is to avoid any other processes using the block device that the
+# root partition is on, which would cause the sfdisk 'BLKRRPART' to fail.
+udevadm settle --timeout ${ROOTDELAY:-30} ||
+	error "GROWROOT: WARNING: udevadm settle prior to growpart failed"
+
 if out=$(growpart "${rootdisk}" "${partnum}" 2>&1); then
 	case "$out" in
 		CHANGED:*) echo "GROWROOT: $out";;