rules sort order: /lib, /run, /etc

After long consideration we came to the conclusion that user
configuration in /etc should always override the (generally
computer generated) configuration in /run. User configuration
should always be what matters over anything else. Hence rearrange
the search orders accordingly. In general this should change
very little as overriding like this is seldomn done so far,
and the order between /etc and /usr stays the same.

4 files changed, 19 insertions, 13 deletions

diff --git a/NEWS b/NEWS
index 00ee648c..b19cf7b5 100644
--- a/NEWS
+++ b/NEWS
@@ -4,6 +4,12 @@ The udev-acl tool is no longer provided, it will be part of a future
 ConsoleKit release. On systemd systems, advanced ConsoleKit and udev-acl
 functionality are provided by systemd.
 
+Rules files in /etc/udev/rules.s/ with the same name as rules files in
+/run/udev/rules.d/ now always have precedence. The stack of files is now:
+/usr/lib (package), /run (runtime, auto-generated), /etc (admin), while
+the later ones override the earlier ones. In other words: the admin has
+always the last say.
+
 
 udev 181
 ========
diff --git a/src/libudev.c b/src/libudev.c
index be24329a..d954daef 100644
--- a/src/libudev.c
+++ b/src/libudev.c
@@ -236,7 +236,7 @@ UDEV_EXPORT struct udev *udev_new(void)
                 fclose(f);
         }
 
-        /* environment overwrites config */
+        /* environment overrides config */
         env = getenv("UDEV_LOG");
         if (env != NULL)
                 udev_set_log_priority(udev, util_log_priority(env));
@@ -260,15 +260,15 @@ UDEV_EXPORT struct udev *udev_new(void)
                 if (!udev->rules_path[0])
                         goto err;
 
+                /* /run/udev -- runtime rules */
+                if (asprintf(&udev->rules_path[2], "%s/rules.d", udev->run_path) < 0)
+                        goto err;
+
                 /* /etc/udev -- local administration rules */
                 udev->rules_path[1] = strdup(SYSCONFDIR "/udev/rules.d");
                 if (!udev->rules_path[1])
                         goto err;
 
-                /* /run/udev -- runtime rules */
-                if (asprintf(&udev->rules_path[2], "%s/rules.d", udev->run_path) < 0)
-                        goto err;
-
                 udev->rules_path_count = 3;
         }
 
diff --git a/src/udev-rules.c b/src/udev-rules.c
index a5b4b730..8a85eae7 100644
--- a/src/udev-rules.c
+++ b/src/udev-rules.c
@@ -1737,7 +1737,7 @@ static int add_matching_files(struct udev *udev, struct udev_list *file_list, co
                 dbg(udev, "put file '%s' into list\n", filename);
                 /*
                  * the basename is the key, the filename the value
-                 * identical basenames from different directories overwrite each other
+                 * identical basenames from different directories override each other
                  * entries are sorted after basename
                  */
                 udev_list_entry_add(file_list, dent->d_name, filename);
diff --git a/src/udev.xml b/src/udev.xml
index 4de434ee..8eb583a8 100644
--- a/src/udev.xml
+++ b/src/udev.xml
@@ -72,15 +72,15 @@
     <refsect2><title>Rules files</title>
       <para>The udev rules are read from the files located in the
       system rules directory <filename>/usr/lib/udev/rules.d</filename>,
-      the local administration directory <filename>/etc/udev/rules.d</filename>
-      and the volatile runtime directory <filename>/run/udev/rules.d</filename>.
+      the volatile runtime directory <filename>/run/udev/rules.d</filename>
+      and the local administration directory <filename>/etc/udev/rules.d</filename>.
       All rules files are collectively sorted and processed in lexical order,
       regardless of the directories in which they live. However, files with
-      identical file names replace each other. Files in <filename>/run</filename>
-      have the highest priority, files in <filename>/etc</filename> take precedence
+      identical file names replace each other. Files in <filename>/etc</filename>
+      have the highest priority, files in <filename>/run</filename> take precedence
       over files with the same name in <filename>/lib</filename>. This can be
-      used to overwrite a system rules file if needed; a symlink in
-      <filename>/etc</filename> with the same name as a rules file in
+      used to override a system-supplied rules file with a local file if needed;
+      a symlink in <filename>/etc</filename> with the same name as a rules file in
       <filename>/lib</filename>, pointing to <filename>/dev/null</filename>,
       disables the rules file entirely.</para>
 
@@ -343,7 +343,7 @@
         <varlistentry>
           <term><option>OWNER, GROUP, MODE</option></term>
           <listitem>
-            <para>The permissions for the device node. Every specified value overwrites
+            <para>The permissions for the device node. Every specified value overrides
             the compiled-in default value.</para>
           </listitem>
         </varlistentry>