挂载iPod时发生多次挂载事件

Question

I am working on an app which has to detect if a storage volume is mounted or unmounted. I am using GIO for that. I listening for the mount-added and mount-removed signals. Everything works fine when I mount/unmount a pen drive. However, I am seeing an issue when mounting an iPod. I am getting two callbacks each on mount and unmount. I assumed one of the GMount objects would be shadowed but g_mount_is_shadowed is returning false for both. How do I decide which one to process and which to ignore? I cannot process both. I have to detect the mount/unmount corresponding to the storage device and process only that.

int main()
{
    g_type_init();
    GVolumeMonitor* volume_monitor = g_volume_monitor_get();
    g_signal_connect(G_OBJECT(volume_monitor), "mount-added", G_CALLBACK(mount_added), NULL);
    g_signal_connect(G_OBJECT(volume_monitor), "mount-removed", G_CALLBACK(mount_removed), NULL);

    GMainLoop* main_loop = g_main_loop_new(NULL, FALSE);        
    g_main_loop_run(main_loop);
    ...
}

Answer 1

I have figured it out. GIO emits a mount-added signal for each filesystem that is added. The iPod has two file systems - one for the OS and one for storing music. Hence the repeated callback. The same happens on unmount. This has nothing to do with shadowed mounts. Unfortunately, I still don't know how to distinguish between the two mounts. The only difference GIO shows is that one of the GMount objects does not have a GVolume object associated with it. I don't know how to interpret that.