From 64db924e2232aa8a2bee5aa177d647fcc1589a4c Mon Sep 17 00:00:00 2001
From: Marco Amadori <marco.amadori@gmail.com>
Date: Fri, 19 Sep 2008 00:31:57 +0200
Subject: [PATCH] live-snapshot: fixed include-list handling.

* When "/etc/live-snapshot.list" is present, all standard files and
  directories listed there are saved on shutdown.
  Now it saves them only if they are modified, and also handles
  dangling symbolic links. This beaviour will be gentle to live-systems
  upgrades on the same hardware since new unmodified to-be-snapshotted files
  will be no more overwritten by old unnecessary saved cruft.
  It still does not handle removal of deleted files.
---
 bin/live-snapshot | 38 ++++++++++++++++++++++++++++++++------
 1 file changed, 32 insertions(+), 6 deletions(-)

diff --git a/bin/live-snapshot b/bin/live-snapshot
index f77541f..5606436 100755
--- a/bin/live-snapshot
+++ b/bin/live-snapshot
@@ -320,23 +320,49 @@ Mount_device ()
 	esac
 }
 
+Entry_is_modified ()
+{
+	# Returns true if file exists and it is also present in "cow" directory
+	# This means it is modified in respect to read-only media, so it deserve
+	# to be saved
+
+	entry="${1}"
+
+	if [ -e "${entry}" ] || [ -L "${entry}" ]
+	then
+		if [ -e "${DEF_SNAP_COW}/${entry}" ] || [ -L "${DEF_SNAP_COW}/${entry}" ]
+		then
+			return 0
+		fi
+	fi
+	return 1
+}
+
 Do_filelist ()
 {
-	# BUGS: supports only cpio.gz types right now
+	# BUGS: supports only cpio.gz types, and do not handle deleted files yet
+
 	TMP_FILELIST=$1
 	if [ -f "${SNAP_LIST}" ]
 	then
 		# Generate include list
 		for entry in $(cat "${SNAP_LIST}" | grep -v '^#.*$' | grep -v '^ *$')
 		do
-			if [ -f "${entry}" ]
-			then
-				printf "%s\000" "${entry}" >> "${TMP_FILELIST}"
-			elif [ -d "${entry}" ]
+			if [ -d "${entry}" ]
 			then
 				cd /
-				find "${entry}" -print0 >> "${TMP_FILELIST}"
+				find "${entry}" | while read line
+				do
+					if Entry_is_modified "${line}"
+					then
+						printf "%s\000" "${line}" >> "${TMP_FILELIST}"
+					fi
+				done
 				cd "${OLDPWD}"
+			elif Entry_is_modified "${entry}"
+			then
+				# if file exists and it is modified
+				printf "%s\000" "${entry}" >> "${TMP_FILELIST}"
 			fi
 		done
 
-- 
2.1.4