Comment 20 for bug 1834250

Setup:
--

Add '/dev/sda' from the host to a Focal LXD container:

 $ lxc launch ubuntu:focal 'focal-container'
 $ lxc config device add 'focal-container' 'lxc-dev-sda' unix-block source='/dev/sda' path='/dev/sda'

Device:
---

 $ grep ^ /sys/block/sda/{removable,device/{vendor,model,rev}}
 /sys/block/sda/removable:1
 /sys/block/sda/device/vendor:Generic-
 /sys/block/sda/device/model:SD/MMC
 /sys/block/sda/device/rev:1.00

Original:
---

Error messages:

 $ sudo vgs
   /dev/sda: open failed: No medium found
   /dev/sda: open failed: No medium found

 $ echo $?
 0

NOTE syscalls/error codes for /dev/sda:

 $ sudo strace -f -e openat vgs 2>&1 | grep /dev/sda
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_DIRECT|O_NOATIME) = -1 ENOMEDIUM (No medium found)
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_NOATIME) = -1 ENOMEDIUM (No medium found)
   /dev/sda: open failed: No medium found
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_DIRECT|O_NOATIME) = -1 ENOMEDIUM (No medium found)
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_NOATIME) = -1 ENOMEDIUM (No medium found)
   /dev/sda: open failed: No medium found

Patched:
---

No messages:

 $ sudo vgs

 $ echo $?
 0

SAME syscalls/error codes for /dev/sda:

 $ sudo strace -f -e openat vgs 2>&1 | grep /dev/sda
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_DIRECT|O_NOATIME) = -1 ENOMEDIUM (No medium found)
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_NOATIME) = -1 ENOMEDIUM (No medium found)
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_DIRECT|O_NOATIME) = -1 ENOMEDIUM (No medium found)
 openat(AT_FDCWD, "/dev/sda", O_RDONLY|O_NOATIME) = -1 ENOMEDIUM (No medium found)