create udevdb files only if somehting interesting happened

Device nodes created with the default rule, without any symlink or option
are no longer saved to the udevdb. This saves us ~3 MB RAM for pretty much
useless files on tmpfs.
Note: HAL needs a fix to handle this correctly. It's already available on
the list.

Signed-off-by: Kay Sievers <kay.sievers@suse.de>

2 files changed, 25 insertions, 15 deletions

diff --git a/udev_db.c b/udev_db.c
index 264af79d06..6f10b1e58d 100644
--- a/udev_db.c
+++ b/udev_db.c
@@ -68,10 +68,18 @@ int udev_db_add_device(struct udevice *udev)
 	if (udev->test_run)
 		return 0;
 
-	get_db_filename(udev->devpath, filename, sizeof(filename));
+	/* don't write anything if udev created only the node with the
+	 * kernel name without any interesting data to remember
+	 */
+	if (strcmp(udev->name, udev->kernel_name) == 0 &&
+	    list_empty(&udev->symlink_list) && list_empty(&udev->env_list) &&
+	    !udev->partitions && !udev->ignore_remove) {
+		dbg("nothing interesting to store in udevdb, skip");
+		goto exit;
+	}
 
+	get_db_filename(udev->devpath, filename, sizeof(filename));
 	create_path(filename);
-
 	f = fopen(filename, "w");
 	if (f == NULL) {
 		err("unable to create db file '%s'", filename);
@@ -84,12 +92,15 @@ int udev_db_add_device(struct udevice *udev)
 	list_for_each_entry(name_loop, &udev->symlink_list, node)
 		fprintf(f, "S:%s\n", name_loop->name);
 	fprintf(f, "M:%u:%u\n", major(udev->devt), minor(udev->devt));
-	fprintf(f, "A:%u\n", udev->partitions);
-	fprintf(f, "R:%u\n", udev->ignore_remove);
+	if (udev->partitions)
+		fprintf(f, "A:%u\n", udev->partitions);
+	if (udev->ignore_remove)
+		fprintf(f, "R:%u\n", udev->ignore_remove);
 	list_for_each_entry(name_loop, &udev->env_list, node)
 		fprintf(f, "E:%s\n", name_loop->name);
 	fclose(f);
 
+exit:
 	return 0;
 }
 
diff --git a/udev_remove.c b/udev_remove.c
index cf28ff37a9..b9a4384ee0 100644
--- a/udev_remove.c
+++ b/udev_remove.c
@@ -143,18 +143,17 @@ int udev_remove_device(struct udevice *udev)
 	if (udev->type != DEV_BLOCK && udev->type != DEV_CLASS)
 		return 0;
 
-	/* remove node only if we can find it in our database */
-	if (udev_db_get_device(udev, udev->devpath) != 0) {
-		dbg("'%s' not found in database, ignore event", udev->name);
-		return -1;
-	}
-	if (udev->ignore_remove) {
-		dbg("remove event for '%s' requested to be ignored by rule", udev->name);
-		return 0;
+	if (udev_db_get_device(udev, udev->devpath) == 0) {
+		if (udev->ignore_remove) {
+			dbg("remove event for '%s' requested to be ignored by rule", udev->name);
+			return 0;
+		}
+		dbg("remove name='%s'", udev->name);
+		udev_db_delete_device(udev);
+	} else {
+		dbg("'%s' not found in database, using kernel name '%s'", udev->devpath, udev->kernel_name);
+		strlcpy(udev->name, udev->kernel_name, sizeof(udev->name));
 	}
-	dbg("remove name='%s'", udev->name);
-	udev_db_delete_device(udev);
-
 	/* use full path to the environment */
 	snprintf(udev->devname, sizeof(udev->devname), "%s/%s", udev_root, udev->name);
 	udev->devname[sizeof(udev->devname)-1] = '\0';