ERROR: The upload destination folder does not appear to be writable - php

Question

Which file permission should I use for uploading and downloading files to a folder in codeigniter?
My whole project is been hosted on FileZilla.
NOTE: Uploading downloading works perfectly fine when website is hosted loacally.
Error only occurs when hosted through FileZilla.
My Upload/Download folder is present in root directory of codeigniter (Directory where Application folder is present).
Upload Controller Code
public function do_upload(){
$rti_details['rtino'] = $this->input->post("rtino");
$rtino_result = $this->rti_model->get_rti_details_by_rtino($rti_details['rtino']);
if(!$rtino_result){
$upload=$this->upload_file('rtifile',$this->input->post('rtino'));
if($upload)
{
$data = array('rti_no'=>$this->input->post('rtino'),
'filer_name'=>$this->input->post('filername'),
'filer_add'=>$this->input->post('fileradd'),
'city'=>$this->input->post('city'),
'state'=>$this->input->post('state'),
'pin_code'=>$this->input->post('pin_code'),
'rti_cat'=>$this->input->post('rti_cat'),
'rti_file'=>$upload['full_path'],
'filed_on'=>$this->input->post('filedon')
);
$this->rti_model->insert_rti($data);
}
$result = true;
}
else
$result = false;
if($result)
$this->session->set_flashdata("flashSuccess","RTI added successfully");
else
$this->session->set_flashdata("flashError","Error in adding RTI. This RTI Number Already Exist.");
redirect("rti/rti_file");
}
private function upload_file($name ='',$sno = 0)
{
if($name=='rtifile'){ $config['upload_path'] = 'assets/rti_uploads/rti_file/'; }
if($name=='coverletter'){ $config['upload_path'] = 'assets/rti_uploads/cover_letter/'; }
if($name=='fullreply'){ $config['upload_path'] = 'assets/rti_uploads/full_reply/'; }
$config['allowed_types'] = 'pdf';
$config['max_size'] = '2050';
if(isset($_FILES[$name]['name']))
{
if($_FILES[$name]['name'] == "")
$filename = "";
else
{
$filename=$this->security->sanitize_filename(strtolower($_FILES[$name]['name']));
$ext = strrchr( $filename, '.' );
if($name=='rtifile'){ $filename='RTI_'.$sno.'_'.date('YmdHis').$ext; }
if($name=='coverletter'){ $filename='COVER_'.$sno.'_'.date('YmdHis').$ext; }
if($name=='fullreply'){ $filename='FULLREPLY_'.$sno.'_'.date('YmdHis').$ext; }
}
}
else
{
$this->session->set_flashdata('flashError','ERROR: File Name not set.');
redirect('rti/rti_file');
return FALSE;
}
$config['file_name'] = $filename;
if(!is_dir($config['upload_path']))
{
mkdir($config['upload_path'],0777,TRUE);
}
$this->load->library('upload', $config);
$this->upload->initialize($config);
if ( ! $this->upload->do_upload($name))
{
$this->session->set_flashdata('flashError',$this->upload->display_errors('',''));
redirect('rti/rti_file');
return FALSE;
}
else
{
$upload_data = $this->upload->data();
return $upload_data;
}
}

Answer 1

From the documentation:
You’ll need a destination directory for your uploaded images. Create a
directory at the root of your CodeIgniter installation called uploads
and set its file permissions to 777.
http://www.codeigniter.com/user_guide/libraries/file_uploading.html#the-upload-directory
Best wishes,
Paul