From e58c591e5a969523356aafe7e8d308b42f0f401b Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 14 Oct 2013 19:01:09 +0200
Subject: [PATCH] backlight: include ID_PATH in file names for backlight
 settings

Much like for rfkill devices we should provide some stability regarding
enumeration order, hence include the stable bits of the device path in
the file name we store settings under.

(cherry picked from commit be3f52f4ed02a9256b1577719677b32a17b525ac)

Conflicts:
	rules/99-systemd.rules.in
	src/rfkill/rfkill.c
---
 rules/99-systemd.rules.in |  4 ++--
 src/backlight/backlight.c | 29 ++++++++++++++++++++++++++---
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/rules/99-systemd.rules.in b/rules/99-systemd.rules.in
index ff0e771..dd6e7f1 100644
--- a/rules/99-systemd.rules.in
+++ b/rules/99-systemd.rules.in
@@ -57,8 +57,8 @@ ACTION=="add", SUBSYSTEM=="net", KERNEL!="lo", RUN+="@rootlibexecdir@/systemd-sy
 # Pull in backlight save/restore for all backlight devices and
 # keyboard backlights
 
-SUBSYSTEM=="backlight", TAG+="systemd", ENV{SYSTEMD_WANTS}+="systemd-backlight@$name.service"
-SUBSYSTEM=="leds", KERNEL=="*kbd_backlight", TAG+="systemd", ENV{SYSTEMD_WANTS}+="systemd-backlight@$name.service"
+SUBSYSTEM=="backlight", TAG+="systemd", IMPORT{builtin}="path_id", ENV{SYSTEMD_WANTS}+="systemd-backlight@$name.service"
+SUBSYSTEM=="leds", KERNEL=="*kbd_backlight", TAG+="systemd", IMPORT{builtin}="path_id", ENV{SYSTEMD_WANTS}+="systemd-backlight@$name.service"
 
 # Asynchronously mount file systems implemented by these modules as
 # soon as they are loaded.
diff --git a/src/backlight/backlight.c b/src/backlight/backlight.c
index 51a67a0..e8cdad6 100644
--- a/src/backlight/backlight.c
+++ b/src/backlight/backlight.c
@@ -195,8 +195,8 @@ static bool validate_device(struct udev *udev, struct udev_device *device) {
 int main(int argc, char *argv[]) {
         _cleanup_udev_unref_ struct udev *udev = NULL;
         _cleanup_udev_device_unref_ struct udev_device *device = NULL;
-        _cleanup_free_ char *saved = NULL, *ss = NULL;
-        const char *sysname;
+        _cleanup_free_ char *saved = NULL, *ss = NULL, *escaped_ss = NULL, *escaped_sysname = NULL, *escaped_path_id = NULL;
+        const char *sysname, *path_id;
         int r;
 
         if (argc != 3) {
@@ -252,7 +252,30 @@ int main(int argc, char *argv[]) {
                 return EXIT_FAILURE;
         }
 
-        saved = strjoin("/var/lib/systemd/backlight/", ss, ":", sysname, NULL);
+        escaped_ss = cescape(ss);
+        if (!escaped_ss) {
+                log_oom();
+                return EXIT_FAILURE;
+        }
+
+        escaped_sysname = cescape(sysname);
+        if (!escaped_sysname) {
+                log_oom();
+                return EXIT_FAILURE;
+        }
+
+        path_id = udev_device_get_property_value(device, "ID_PATH");
+        if (path_id) {
+                escaped_path_id = cescape(path_id);
+                if (!escaped_path_id) {
+                        log_oom();
+                        return EXIT_FAILURE;
+                }
+
+                saved = strjoin("/var/lib/systemd/backlight/", escaped_path_id, ":", escaped_ss, ":", escaped_sysname, NULL);
+        } else
+                saved = strjoin("/var/lib/systemd/backlight/", escaped_ss, ":", escaped_sysname, NULL);
+
         if (!saved) {
                 log_oom();
                 return EXIT_FAILURE;