If @cancellable is not %NULL, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
When the operation is finished, @callback will be called.
You can then call g_file_unmount_mountable_finish() to get
the result of the operation.
Unmounts a file of type #G_FILE_TYPE_MOUNTABLE.
If @cancellable is not %NULL, then the operation can be cancelled by triggering the cancellable object from another thread. If the operation was cancelled, the error %G_IO_ERROR_CANCELLED will be returned.
When the operation is finished, @callback will be called. You can then call g_file_unmount_mountable_finish() to get the result of the operation.