Shared LAN/USB structure

[oktav]

Hello all. First of all let me introduce myself. I'm oktav from Italy and i'm having a little problem sharing files in a eth/usb network.

First of all i'll just post a picture with the infrastructure I presently have:



Devices I have:

1. FTP Client that's automatically pushing content on an FTP Server (Asus WL 500 PV2)
2. Asus WL 500 PV2 with DD-WRT v24-sp2 (12/13/08) mega - build 11181 (used only as NAS, no routing, WAN, Wireless funtions are enabled) with also an FTP Server as optware and a mounted External HDD on USB0 (USB1 is free)
3. External HDD formatted with EXT3 Filesystem used for depositing files received through FTP from my FTP Client / Pusher
4. Finally, I have a USB player that needs to have attached an external HDD. Upon connecting the HDD to the player it sees it as external storage device and it can access all the files present.

Considerations:

1. The FTP Client / Pusher cannot be configured. All settings available to me are: host, username, password (for the FTP transfer)
2. The USB player also cannot be configured and it's only input is a USB interface
3. I have total control of the asus, it can be flashed, configured, and all settings control is mine
4. Every device uses UNIX releases so basically all devices use EXT3 Filesystem
5. All devices are in the same room
6. Link C is doesn't exist yet. Link A and B are active one at a time

Actions:

At the moment i can transfer files from the FTP Client to the Asus and have the content stored on the External HDD. Then unplug the HDD from the Asus and plug it in the USB player. The files are recognized and played successfully.

Problems:

I want to be able to make the External HDD visible by both devices: Asus and USB player. So in this case I wouldn't have to unplug the HDD from the asus nor the player thus avoiding writing errors, remount errors (by the asus) and any other malfunction.
Is there a new firmware release that allows me to do that? Or some special setting on the asus to allow me to do this?
In the case this wouldn't be possible I would try to set some warning on the asus LEDs while content is being written if possible.