Samba and usbmount: can't write on automounted device

Question

This is my problem:

I configured my RPi with Debian:

• Samba shares a specific folder, that is readable-writeable-executable from my home network: /media/

• usbmount automount USB devices when inserted in my RPi, in /media/usb

• No users should be logged in to do this

When I insert an USB device, usbmount mount it correctly, so RPi can write on it and a person can READ it through network. BUT no persons are allowed to WRITE on it through network.

Checking permissions on /media/usb I found that:

• BEFORE usbmount mount device /media/usb is rwx-rwx-rwx
• AFTER usbmount mount device /media/usb became rwx-r-r, so only root (usbmount work mounting devices as root) can write on it

So I've tryed to change the FS_MOUNTPOINTS="" line in /etc/usbmount/usbmount.conf file but I don't know how to force usbmount to automount devices rwx-rwx-rwx or with "low-user write permission".

Answer 1

After a lot of test i edited the FS_MOUNTOPTIONS line:

FS_MOUNTOPTIONS="-fstype=vfat,umask=0000"

Where

• vfat is the filesystem
• umask=0000 is the permission of the file and folder. 0000 means rwx-rwx-rwx

Answer 2

I've had this problem on linux once. It turned out that mounting a drive will apply the root directory permissions to the mount point. A simple chmod 777 /media/usb after mounting should fix it.

You might also want to add ,dmask=000,fmask=000 (or preferably 002 and using a group) to the FS_MOUNTOPTIONS line.