udevd: use dev_t or netif ifindex as database key

We need to preserve the database of network interfaces while we
rename them. Use the kernel's numbers wherever possible, instead
of the device names.

Fix wrong database filenames which contain a '/', translated
from '!' in the kernel name.

Fix segfault for kobject pathes where the subsystem can not be
determined from sysfs.

1 files changed, 61 insertions, 0 deletions

diff --git a/udev/udevadm-info.c b/udev/udevadm-info.c
index b3b31ebafe..7206f4fcf6 100644
--- a/udev/udevadm-info.c
+++ b/udev/udevadm-info.c
@@ -195,6 +195,60 @@ static int export_devices(struct udev *udev)
 	return 0;
 }
 
+static int convert_db(struct udev *udev)
+{
+	struct udev_enumerate *udev_enumerate;
+	struct udev_list_entry *list_entry;
+
+	udev_enumerate = udev_enumerate_new(udev);
+	if (udev_enumerate == NULL)
+		return -1;
+	udev_enumerate_scan_devices(udev_enumerate);
+	udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
+		struct udev_device *device;
+
+		device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
+		if (device != NULL) {
+			const char *id;
+			struct stat statbuf;
+			char to[UTIL_PATH_SIZE];
+			char devpath[UTIL_PATH_SIZE];
+			char from[UTIL_PATH_SIZE];
+
+			id = udev_device_get_id_filename(device);
+			if (id == NULL)
+				goto next;
+			util_strscpyl(to, sizeof(to), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
+
+			/* do not overwrite a new database file */
+			if (lstat(to, &statbuf) == 0)
+				goto next;
+
+			/* find old database with $subsys:$sysname */
+			util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
+				     "/.udev/db/", udev_device_get_subsystem(device), ":",
+				     udev_device_get_sysname(device), NULL);
+			if (lstat(from, &statbuf) == 0) {
+				rename(from, to);
+				goto next;
+			}
+
+			/* find old database with the encoded devpath */
+			util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
+			util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
+				      "/.udev/db/", devpath, NULL);
+			if (lstat(from, &statbuf) == 0) {
+				rename(from, to);
+				goto next;
+			}
+next:
+			udev_device_unref(device);
+		}
+	}
+	udev_enumerate_unref(udev_enumerate);
+	return 0;
+}
+
 int udevadm_info(struct udev *udev, int argc, char *argv[])
 {
 	struct udev_device *device = NULL;
@@ -212,6 +266,7 @@ int udevadm_info(struct udev *udev, int argc, char *argv[])
 		{ "query", required_argument, NULL, 'q' },
 		{ "attribute-walk", no_argument, NULL, 'a' },
 		{ "export-db", no_argument, NULL, 'e' },
+		{ "convert-db", no_argument, NULL, 'C' },
 		{ "root", no_argument, NULL, 'r' },
 		{ "device-id-of-file", required_argument, NULL, 'd' },
 		{ "export", no_argument, NULL, 'x' },
@@ -336,6 +391,9 @@ int udevadm_info(struct udev *udev, int argc, char *argv[])
 		case 'e':
 			export_devices(udev);
 			goto exit;
+		case 'C':
+			convert_db(udev);
+			goto exit;
 		case 'x':
 			export = true;
 			break;
@@ -359,7 +417,10 @@ int udevadm_info(struct udev *udev, int argc, char *argv[])
 			       "  --attribute-walk           print all key matches while walking along the chain\n"
 			       "                             of parent devices\n"
 			       "  --device-id-of-file=<file> print major:minor of device containing this file\n"
+			       "  --export                   export key/value pairs\n"
+			       "  --export-prefix            export the key name with a prefix\n"
 			       "  --export-db                export the content of the udev database\n"
+			       "  --convert-db               convert older version of database without a reboot\n"
 			       "  --help\n\n");
 			goto exit;
 		default: