handle devtmpfs nodes

UDev follows the kernel given name, and re-uses the kernel created
device node. If the kernel and spcecified udev rules disagree, the
udev specified node node is created and the kernel-created on is
deleted.

3 files changed, 31 insertions, 5 deletions

diff --git a/udev/lib/libudev-device.c b/udev/lib/libudev-device.c
index 92b2d18b83..8e29efff86 100644
--- a/udev/lib/libudev-device.c
+++ b/udev/lib/libudev-device.c
@@ -37,6 +37,7 @@ struct udev_device {
 	char *action;
 	char *devpath_old;
 	char *physdevpath;
+	char *knodename;
 	char **envp;
 	char *monitor_buf;
 	size_t monitor_buf_len;
@@ -208,6 +209,8 @@ int udev_device_read_uevent_file(struct udev_device *udev_device)
 			maj = strtoull(&line[6], NULL, 10);
 		else if (strncmp(line, "MINOR=", 6) == 0)
 			min = strtoull(&line[6], NULL, 10);
+		else if (strncmp(line, "DEVNAME=", 8) == 0)
+			udev_device_set_knodename(udev_device, &line[8]);
 
 		udev_device_add_property_from_string(udev_device, line);
 	}
@@ -621,6 +624,7 @@ void udev_device_unref(struct udev_device *udev_device)
 	free(udev_device->action);
 	free(udev_device->driver);
 	free(udev_device->devpath_old);
+	free(udev_device->knodename);
 	free(udev_device->physdevpath);
 	udev_list_cleanup_entries(udev_device->udev, &udev_device->sysattr_list);
 	free(udev_device->envp);
@@ -1175,6 +1179,19 @@ int udev_device_set_devpath_old(struct udev_device *udev_device, const char *dev
 	return 0;
 }
 
+const char *udev_device_get_knodename(struct udev_device *udev_device)
+{
+	return udev_device->knodename;
+}
+
+int udev_device_set_knodename(struct udev_device *udev_device, const char *knodename)
+{
+	udev_device->knodename = strdup(knodename);
+	if (udev_device->knodename == NULL)
+		return -ENOMEM;
+	return 0;
+}
+
 const char *udev_device_get_physdevpath(struct udev_device *udev_device)
 {
 	return udev_device->physdevpath;
diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c
index c87ff7434f..fc904c4a7c 100644
--- a/udev/lib/libudev-monitor.c
+++ b/udev/lib/libudev-monitor.c
@@ -445,6 +445,7 @@ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monito
 	int action_set = 0;
 	int maj = 0;
 	int min = 0;
+	int is_kernel = 0;
 
 retry:
 	if (udev_monitor == NULL)
@@ -480,9 +481,12 @@ retry:
 			info(udev_monitor->udev, "unicast netlink message ignored\n");
 			return NULL;
 		}
-		if ((snl.nl_groups == UDEV_MONITOR_KERNEL) && (snl.nl_pid > 0)) {
-			info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
-			return NULL;
+		if (snl.nl_groups == UDEV_MONITOR_KERNEL) {
+			if (snl.nl_pid > 0) {
+				info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
+				return NULL;
+			}
+			is_kernel = 1;
 		}
 	}
 
@@ -551,7 +555,10 @@ retry:
 		} else if (strncmp(key, "DEVTYPE=", 8) == 0) {
 			udev_device_set_devtype(udev_device, &key[8]);
 		} else if (strncmp(key, "DEVNAME=", 8) == 0) {
-			udev_device_set_devnode(udev_device, &key[8]);
+			if (is_kernel)
+				udev_device_set_knodename(udev_device, &key[8]);
+			else
+				udev_device_set_devnode(udev_device, &key[8]);
 		} else if (strncmp(key, "DEVLINKS=", 9) == 0) {
 			char devlinks[UTIL_PATH_SIZE];
 			char *slink;
@@ -586,7 +593,7 @@ retry:
 		} else if (strncmp(key, "TIMEOUT=", 8) == 0) {
 			udev_device_set_timeout(udev_device, strtoull(&key[8], NULL, 10));
 		} else if (strncmp(key, "PHYSDEV", 7) == 0) {
-			/* skip deprecated values */
+			/* suppress deprecated values */
 			continue;
 		} else {
 			udev_device_add_property_from_string(udev_device, key);
diff --git a/udev/lib/libudev-private.h b/udev/lib/libudev-private.h
index b283ff4ac3..8723cd7914 100644
--- a/udev/lib/libudev-private.h
+++ b/udev/lib/libudev-private.h
@@ -62,6 +62,8 @@ int udev_device_set_action(struct udev_device *udev_device, const char *action);
 int udev_device_set_driver(struct udev_device *udev_device, const char *driver);
 const char *udev_device_get_devpath_old(struct udev_device *udev_device);
 int udev_device_set_devpath_old(struct udev_device *udev_device, const char *devpath_old);
+const char *udev_device_get_knodename(struct udev_device *udev_device);
+int udev_device_set_knodename(struct udev_device *udev_device, const char *knodename);
 const char *udev_device_get_physdevpath(struct udev_device *udev_device);
 int udev_device_set_physdevpath(struct udev_device *udev_device, const char *physdevpath);
 int udev_device_get_timeout(struct udev_device *udev_device);