From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 3 Dec 2024 19:31:31 +0000 (+0900)
Subject: udev: reload .rules files and builtins only when necessary
X-Git-Tag: v258-rc1~1809^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=0f72af536f957b5755551de5f1815baef8f377b7;p=thirdparty%2Fsystemd.git

udev: reload .rules files and builtins only when necessary

Previously, even if e.g. .rules files are unchanged, all .rules files
are reloaded when other kind of config files like .link files or
.hwdb.bin are changed, vice versa.
---

diff --git a/src/udev/udev-builtin.c b/src/udev/udev-builtin.c
index 41a39b5cd62..b47ca37d55b 100644
--- a/src/udev/udev-builtin.c
+++ b/src/udev/udev-builtin.c
@@ -42,11 +42,28 @@ void udev_builtin_exit(void) {
                         (*b)->exit();
 }
 
-bool udev_builtin_should_reload(void) {
+UdevReloadFlags udev_builtin_should_reload(void) {
+        UdevReloadFlags flags = 0;
+
         for (UdevBuiltinCommand i = 0; i < _UDEV_BUILTIN_MAX; i++)
                 if (builtins[i] && builtins[i]->should_reload && builtins[i]->should_reload())
-                        return true;
-        return false;
+                        flags |= 1u << i;
+
+        if (flags != 0)
+                flags |= UDEV_RELOAD_KILL_WORKERS;
+
+        return flags;
+}
+
+void udev_builtin_reload(UdevReloadFlags flags) {
+        for (UdevBuiltinCommand i = 0; i < _UDEV_BUILTIN_MAX; i++) {
+                if (!FLAGS_SET(flags, 1u << i) || !builtins[i])
+                        continue;
+                if (builtins[i]->exit)
+                        builtins[i]->exit();
+                if (builtins[i]->init)
+                        builtins[i]->init();
+        }
 }
 
 void udev_builtin_list(void) {
diff --git a/src/udev/udev-builtin.h b/src/udev/udev-builtin.h
index 8c2016e5f0c..3b5f3bd120b 100644
--- a/src/udev/udev-builtin.h
+++ b/src/udev/udev-builtin.h
@@ -59,7 +59,8 @@ const char* udev_builtin_name(UdevBuiltinCommand cmd);
 bool udev_builtin_run_once(UdevBuiltinCommand cmd);
 int udev_builtin_run(UdevEvent *event, UdevBuiltinCommand cmd, const char *command);
 void udev_builtin_list(void);
-bool udev_builtin_should_reload(void);
+UdevReloadFlags udev_builtin_should_reload(void);
+void udev_builtin_reload(UdevReloadFlags flags);
 int udev_builtin_add_property(UdevEvent *event, const char *key, const char *val);
 int udev_builtin_add_propertyf(UdevEvent *event, const char *key, const char *valf, ...) _printf_(3, 4);
 int udev_builtin_import_property(UdevEvent *event, const char *key);
diff --git a/src/udev/udev-def.h b/src/udev/udev-def.h
index 6ff3feacec1..9d9fc78247d 100644
--- a/src/udev/udev-def.h
+++ b/src/udev/udev-def.h
@@ -55,3 +55,26 @@ typedef enum UdevBuiltinCommand {
         _UDEV_BUILTIN_MAX,
         _UDEV_BUILTIN_INVALID = -EINVAL,
 } UdevBuiltinCommand;
+
+typedef enum UdevReloadFlags {
+#if HAVE_BLKID
+        UDEV_RELOAD_BUILTIN_BLKID    = 1u << UDEV_BUILTIN_BLKID,
+#endif
+        UDEV_RELOAD_BUILTIN_BTRFS    = 1u << UDEV_BUILTIN_BTRFS,
+        UDEV_RELOAD_BUILTIN_HWDB     = 1u << UDEV_BUILTIN_HWDB,
+        UDEV_RELOAD_BUILTIN_INPUT_ID = 1u << UDEV_BUILTIN_INPUT_ID,
+        UDEV_RELOAD_BUILTIN_KEYBOARD = 1u << UDEV_BUILTIN_KEYBOARD,
+#if HAVE_KMOD
+        UDEV_RELOAD_BUILTIN_KMOD     = 1u << UDEV_BUILTIN_KMOD,
+#endif
+        UDEV_RELOAD_BUILTIN_DRIVER   = 1u << UDEV_BUILTIN_NET_DRIVER,
+        UDEV_RELOAD_BUILTIN_NET_ID   = 1u << UDEV_BUILTIN_NET_ID,
+        UDEV_RELOAD_BUILTIN_NET_LINK = 1u << UDEV_BUILTIN_NET_LINK,
+        UDEV_RELOAD_BUILTIN_PATH_ID  = 1u << UDEV_BUILTIN_PATH_ID,
+        UDEV_RELOAD_BUILTIN_USB_ID   = 1u << UDEV_BUILTIN_USB_ID,
+#if HAVE_ACL
+        UDEV_RELOAD_BUILTIN_UACCESS  = 1u << UDEV_BUILTIN_UACCESS,
+#endif
+        UDEV_RELOAD_KILL_WORKERS     = 1u << (_UDEV_BUILTIN_MAX + 0),
+        UDEV_RELOAD_RULES            = 1u << (_UDEV_BUILTIN_MAX + 1),
+} UdevReloadFlags;
diff --git a/src/udev/udev-manager.c b/src/udev/udev-manager.c
index 7f7079bcd2c..c691b8ebed6 100644
--- a/src/udev/udev-manager.c
+++ b/src/udev/udev-manager.c
@@ -262,22 +262,25 @@ static void manager_reload(Manager *manager, bool force) {
         /* Reload SELinux label database, to make the child inherit the up-to-date database. */
         mac_selinux_maybe_reload();
 
-        /* Nothing changed. It is not necessary to reload. */
-        if (!udev_rules_should_reload(manager->rules) && !udev_builtin_should_reload()) {
-
+        UdevReloadFlags flags = udev_builtin_should_reload();
+        if (udev_rules_should_reload(manager->rules))
+                flags |= UDEV_RELOAD_RULES | UDEV_RELOAD_KILL_WORKERS;
+        if (flags == 0) {
+                /* Nothing changed. It is not necessary to reload. */
                 if (!force)
                         return;
 
                 /* If we eat this up, then tell our service manager to just continue */
                 (void) notify_reloading_full("Skipping configuration reloading, nothing changed.");
-        } else {
+        } else
                 (void) notify_reloading();
 
+        if (FLAGS_SET(flags, UDEV_RELOAD_KILL_WORKERS))
                 manager_kill_workers(manager, false);
 
-                udev_builtin_exit();
-                udev_builtin_init();
+        udev_builtin_reload(flags);
 
+        if (FLAGS_SET(flags, UDEV_RELOAD_RULES)) {
                 r = udev_rules_load(&rules, manager->config.resolve_name_timing);
                 if (r < 0)
                         log_warning_errno(r, "Failed to read udev rules, using the previously loaded rules, ignoring: %m");