int device_wait_for_initialization(sd_device *device, const char *subsystem, sd_device **ret) {
_cleanup_(sd_device_monitor_unrefp) sd_device_monitor *monitor = NULL;
_cleanup_(sd_event_unrefp) sd_event *event = NULL;
struct DeviceMonitorData data = {};
int r;
assert(device);
assert(subsystem);
if (sd_device_get_is_initialized(device) > 0) {
if (ret)
*ret = sd_device_ref(device);
return 0;
}
assert_se(sd_device_get_sysname(device, &data.sysname) >= 0);
/* Wait until the device is initialized, so that we can get access to the ID_PATH property */
r = sd_event_new(&event);
if (r < 0)
return log_error_errno(r, "Failed to get default event: %m");
r = sd_device_monitor_new(&monitor);
if (r < 0)
return log_error_errno(r, "Failed to acquire monitor: %m");
r = sd_device_monitor_filter_add_match_subsystem_devtype(monitor, subsystem, NULL);
if (r < 0)
return log_error_errno(r, "Failed to add %s subsystem match to monitor: %m", subsystem);
r = sd_device_monitor_attach_event(monitor, event);
if (r < 0)
return log_error_errno(r, "Failed to attach event to device monitor: %m");
r = sd_device_monitor_start(monitor, device_monitor_handler, &data);
if (r < 0)
return log_error_errno(r, "Failed to start device monitor: %m");
/* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
* yet. */
if (sd_device_get_is_initialized(device) > 0) {
if (ret)
*ret = sd_device_ref(device);
return 0;
}
r = sd_event_loop(event);
if (r < 0)
return log_error_errno(r, "Event loop failed: %m");
if (ret)
*ret = TAKE_PTR(data.device);
return 0;
}
/**
* udev_device_get_is_initialized:
* @udev_device: udev device
*
* Check if udev has already handled the device and has set up
* device node permissions and context, or has renamed a network
* device.
*
* This is only implemented for devices with a device node
* or network interfaces. All other devices return 1 here.
*
* Returns: 1 if the device is set up. 0 otherwise.
**/
_public_ int udev_device_get_is_initialized(struct udev_device *udev_device)
{
int r, initialized;
assert_return(udev_device, -EINVAL);
r = sd_device_get_is_initialized(udev_device->device, &initialized);
if (r < 0) {
errno = -r;
return 0;
}
return initialized;
}
