[Samba] Linux Mint 21.3 client AD joined OK but no usb working

[Rowland Penny]

On Thu, 28 Mar 2024 11:33:16 +0000
Rowland Penny via samba <samba at lists.samba.org> wrote:

> On Wed, 27 Mar 2024 18:13:16 +0000
> Rowland Penny via samba <samba at lists.samba.org> wrote:
> > 
> > Now thinking about apparmor, could this be stopping writing to the
> > drive ?
> > 
> 
> No, I removed apparmor and rebooted, no different.
> 
> Tried to format the drive, but it seems to have gone read only, so
> used another drive and formatted that.
> 
> When I insert the USB drive, it gets mounted on
> /media/rowland/usbdrive1
> 
> Checking the permissions on the path, shows this:
> 
> rowland at devstation:~$ ls -ld /media/
> drwxr-xr-x 4 root root 4096 Mar 27 17:15 /media/
> 
> Anyone can traverse /media
> 
> rowland at devstation:~$ ls -ld /media/rowland/
> drwxr-x---+ 3 root root 4096 Mar 28 09:36 /media/rowland/
> 
> There is an EA, so check that:
> 
> rowland at devstation:~$ getfacl /media/rowland/
> getfacl: Removing leading '/' from absolute path names
> # file: media/rowland/
> # owner: root
> # group: root
> user::rwx
> user:rowland:r-x
> group::---
> mask::r-x
> other::---
> 
> Only 'root', members of the 'root' group and 'rowland' can traverse
> /media/rowland
> 
> rowland at devstation:~$ ls -ld /media/rowland/usbdrive1/
> drwxr-xr-x 3 root root 4096 Mar 28 09:32 /media/rowland/usbdrive1/
> 
> So 'rowland' can traverse to the 'usbdrive1' directory, but only
> 'root' can write to it.
> 
> WHY ??????????
> 
> It mounts the drive in a directory named after the user, it allows the
> user to get to the drive, but then denies the user the ability to
> write to the drive.
> 
> Off to find out just what 'mounts' the drive and how.
> 
> Rowland
> 

It seems that it is udev and udisks2 that automatically mount the USB
drive after it is plugged into a USB port.
The problem is I stated earlier, whilst it is mounted under a directory
with the users name, it is mounted rwx for root and r-x for the user
(others), which, if you think about it, is probably correct for a
removable drive. Whilst the user may have one ID on a computer, they
may have another ID on a different computer.
The only cure I can find is to change the owner of the USB drives
directory, e.g. chown rowland /media/rowland/usbdrive1

Rowland