Yes but, if a “normal” user mounts a USB disk by means of a KDE Plasma session, the mount is performed by means of FUSE.
Jul 22 12:12:37 kernel: usb 1-7.2: new high-speed USB device number 6 using xhci_hcd
Jul 22 12:12:38 kernel: usb 1-7.2: New USB device found, idVendor=0718, idProduct=0628, bcdDevice= 1.00
Jul 22 12:12:38 kernel: usb 1-7.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
Jul 22 12:12:38 kernel: usb 1-7.2: Product: Trans-It Drive
Jul 22 12:12:38 kernel: usb 1-7.2: Manufacturer: TDKMedia
Jul 22 12:12:38 kernel: usb 1-7.2: SerialNumber: 079B0D03BE2413E9
Jul 22 12:12:38 kernel: usb-storage 1-7.2:1.0: USB Mass Storage device detected
Jul 22 12:12:38 kernel: scsi host6: usb-storage 1-7.2:1.0
Jul 22 12:12:38 kernel: usbcore: registered new interface driver usb-storage
Jul 22 12:12:38 kernel: usbcore: registered new interface driver uas
Jul 22 12:12:38 mtp-probe[23062]: checking bus 1, device 6: "/sys/devices/pci0000:00/0000:00:01.2/0000:01:00.0/usb1/1-7>
Jul 22 12:12:38 mtp-probe[23062]: bus: 1, device: 6 was not an MTP device
Jul 22 12:12:38 mtp-probe[23082]: checking bus 1, device 6: "/sys/devices/pci0000:00/0000:00:01.2/0000:01:00.0/usb1/1-7>
Jul 22 12:12:38 mtp-probe[23082]: bus: 1, device: 6 was not an MTP device
Jul 22 12:12:39 kernel: scsi 6:0:0:0: Direct-Access TDKMedia Trans-It Drive PMAP PQ: 0 ANSI: 0 CCS
Jul 22 12:12:39 kernel: sd 6:0:0:0: Attached scsi generic sg4 type 0
Jul 22 12:12:40 kernel: sd 6:0:0:0: [sdc] 7806976 512-byte logical blocks: (4.00 GB/3.72 GiB)
Jul 22 12:12:40 kernel: sd 6:0:0:0: [sdc] Write Protect is off
Jul 22 12:12:40 kernel: sd 6:0:0:0: [sdc] Mode Sense: 23 00 00 00
Jul 22 12:12:40 kernel: sd 6:0:0:0: [sdc] No Caching mode page found
Jul 22 12:12:40 kernel: sd 6:0:0:0: [sdc] Assuming drive cache: write through
Jul 22 12:12:40 kernel: sdc: sdc1
Jul 22 12:12:40 kernel: sd 6:0:0:0: [sdc] Attached SCSI removable disk
> lsblk --fs
sdc
└─sdc1 vfat FAT32 A853-E68B 3,7G 0% /run/media/xxx/A853-E68B
>
> mount | grep '/run/media/'
/dev/sdc1 on /run/media/xxx/A853-E68B type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2)
>
Therefore, any given KDE Plasma Dolphin instance will only be able to access the mounted device if “$USER” translates to the user who first mounted the device.
And, there’s the user protections FUSE places on any given Userspace Mount – <The Linux Kernel Documentation – FUSE>
If, it’s a multi-user system and, all the users have to access a given USB device which one of the users plugged into the system, I would tend to use “autofs” for this Use Case to work around the user protections associated with a Mount which lands in the ‘/run/media/’ directory tree.
Quoting the “fuse” man page –
SECURITY
The fusermount3 program is installed set-user-gid to fuse. This is done to allow users from fuse group to
mount their own filesystem implementations. There must however be some limitations, in order to prevent Bad
User from doing nasty things. Currently those limitations are:
1. The user can only mount on a mountpoint, for which it has write permission
2. The mountpoint is not a sticky directory which isn't owned by the user (like /tmp usually is)
3. No other user (including root) can access the contents of the mounted filesystem.
On the other hand, in ‘/etc/fuse.conf’ there’s this information – it’s also in the “mount.fuse3” man page –
# user_allow_other - Using the allow_other mount option works fine as root, in
# order to have it work as user you need user_allow_other in /etc/fuse.conf as
# well. (This option allows users to use the allow_other option.) You need
# allow_other if you want users other than the owner to access a mounted fuse.
# This option must appear on a line by itself. There is no value, just the
# presence of the option.
#user_allow_other
, I briefly tried on Tumbleweed and I most certainly can create relative symlink in Dolphin. So, I agree - some more details what OP tries to do would be useful.