Comment # 2
on bug 1201114
from Gene Snider
After the first > sudo umount -v -R /mnt/chroot:
> ll /mnt/chroot
total 0
-rw-r--r-- 1 root root 0 Jul 7 13:26 nothing_is_mounted
> mount
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
devtmpfs on /dev type devtmpfs
(rw,nosuid,size=4096k,nr_inodes=1048576,mode=755,inode64)
securityfs on /sys/kernel/security type securityfs
(rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,inode64)
devpts on /dev/pts type devpts
(rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs
(rw,nosuid,nodev,size=3141212k,nr_inodes=819200,mode=755,inode64)
cgroup2 on /sys/fs/cgroup type cgroup2
(rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
efivarfs on /sys/firmware/efi/efivars type efivarfs
(rw,nosuid,nodev,noexec,relatime)
bpf on /sys/fs/bpf type bpf (rw,nosuid,nodev,noexec,relatime,mode=700)
/dev/nvme0n1p4 on / type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=504,subvol=/@/.snapshots/239/snapshot)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs
(rw,relatime,fd=30,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=25704)
mqueue on /dev/mqueue type mqueue (rw,nosuid,nodev,noexec,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime,pagesize=2M)
debugfs on /sys/kernel/debug type debugfs (rw,nosuid,nodev,noexec,relatime)
tracefs on /sys/kernel/tracing type tracefs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,nr_inodes=1048576,inode64)
fusectl on /sys/fs/fuse/connections type fusectl
(rw,nosuid,nodev,noexec,relatime)
configfs on /sys/kernel/config type configfs (rw,nosuid,nodev,noexec,relatime)
/dev/nvme0n1p4 on /.snapshots type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=265,subvol=/@/.snapshots)
/dev/nvme0n1p4 on /boot/grub2/x86_64-efi type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=263,subvol=/@/boot/grub2/x86_64-efi)
/dev/nvme0n1p4 on /boot/grub2/i386-pc type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=264,subvol=/@/boot/grub2/i386-pc)
/dev/nvme0n1p4 on /home type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=262,subvol=/@/home)
/dev/sda1 on /mnt/backups type btrfs
(rw,relatime,ssd,space_cache,subvolid=5,subvol=/)
/dev/nvme0n1p4 on /srv type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=259,subvol=/@/srv)
/dev/nvme0n1p4 on /root type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=260,subvol=/@/root)
/dev/nvme0n1p4 on /opt type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=261,subvol=/@/opt)
/dev/nvme0n1p4 on /var type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=257,subvol=/@/var)
/dev/nvme0n1p4 on /usr/local type btrfs
(rw,relatime,ssd,space_cache=v2,subvolid=258,subvol=/@/usr/local)
/dev/nvme0n1p1 on /boot/efi type vfat
(rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro)
tmpfs on /run/user/1000 type tmpfs
(rw,nosuid,nodev,relatime,size=1570604k,nr_inodes=392651,mode=700,uid=1000,gid=1000,inode64)
gvfsd-fuse on /run/user/1000/gvfs type fuse.gvfsd-fuse
(rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
portal on /run/user/1000/doc type fuse.portal
(rw,nosuid,nodev,relatime,user_id=1000,group_id=1000)
> cat /proc/mounts
proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0
sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0
devtmpfs /dev devtmpfs rw,nosuid,size=4096k,nr_inodes=1048576,mode=755,inode64
0 0
securityfs /sys/kernel/security securityfs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /dev/shm tmpfs rw,nosuid,nodev,inode64 0 0
devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0
0
tmpfs /run tmpfs
rw,nosuid,nodev,size=3141212k,nr_inodes=819200,mode=755,inode64 0 0
cgroup2 /sys/fs/cgroup cgroup2
rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0
pstore /sys/fs/pstore pstore rw,nosuid,nodev,noexec,relatime 0 0
efivarfs /sys/firmware/efi/efivars efivarfs rw,nosuid,nodev,noexec,relatime 0 0
bpf /sys/fs/bpf bpf rw,nosuid,nodev,noexec,relatime,mode=700 0 0
/dev/nvme0n1p4 / btrfs
rw,relatime,ssd,space_cache=v2,subvolid=504,subvol=/@/.snapshots/239/snapshot 0
0
systemd-1 /proc/sys/fs/binfmt_misc autofs
rw,relatime,fd=30,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=25704
0 0
mqueue /dev/mqueue mqueue rw,nosuid,nodev,noexec,relatime 0 0
hugetlbfs /dev/hugepages hugetlbfs rw,relatime,pagesize=2M 0 0
debugfs /sys/kernel/debug debugfs rw,nosuid,nodev,noexec,relatime 0 0
tracefs /sys/kernel/tracing tracefs rw,nosuid,nodev,noexec,relatime 0 0
tmpfs /tmp tmpfs rw,nosuid,nodev,nr_inodes=1048576,inode64 0 0
fusectl /sys/fs/fuse/connections fusectl rw,nosuid,nodev,noexec,relatime 0 0
configfs /sys/kernel/config configfs rw,nosuid,nodev,noexec,relatime 0 0
/dev/nvme0n1p4 /.snapshots btrfs
rw,relatime,ssd,space_cache=v2,subvolid=265,subvol=/@/.snapshots 0 0
/dev/nvme0n1p4 /boot/grub2/x86_64-efi btrfs
rw,relatime,ssd,space_cache=v2,subvolid=263,subvol=/@/boot/grub2/x86_64-efi 0 0
/dev/nvme0n1p4 /boot/grub2/i386-pc btrfs
rw,relatime,ssd,space_cache=v2,subvolid=264,subvol=/@/boot/grub2/i386-pc 0 0
/dev/nvme0n1p4 /home btrfs
rw,relatime,ssd,space_cache=v2,subvolid=262,subvol=/@/home 0 0
/dev/sda1 /mnt/backups btrfs rw,relatime,ssd,space_cache,subvolid=5,subvol=/ 0
0
/dev/nvme0n1p4 /srv btrfs
rw,relatime,ssd,space_cache=v2,subvolid=259,subvol=/@/srv 0 0
/dev/nvme0n1p4 /root btrfs
rw,relatime,ssd,space_cache=v2,subvolid=260,subvol=/@/root 0 0
/dev/nvme0n1p4 /opt btrfs
rw,relatime,ssd,space_cache=v2,subvolid=261,subvol=/@/opt 0 0
/dev/nvme0n1p4 /var btrfs
rw,relatime,ssd,space_cache=v2,subvolid=257,subvol=/@/var 0 0
/dev/nvme0n1p4 /usr/local btrfs
rw,relatime,ssd,space_cache=v2,subvolid=258,subvol=/@/usr/local 0 0
/dev/nvme0n1p1 /boot/efi vfat
rw,relatime,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,utf8,errors=remount-ro
0 0
tmpfs /run/user/1000 tmpfs
rw,nosuid,nodev,relatime,size=1570604k,nr_inodes=392651,mode=700,uid=1000,gid=1000,inode64
0 0
gvfsd-fuse /run/user/1000/gvfs fuse.gvfsd-fuse
rw,nosuid,nodev,relatime,user_id=1000,group_id=1000 0 0
portal /run/user/1000/doc fuse.portal
rw,nosuid,nodev,relatime,user_id=1000,group_id=1000 0 0
I didn't see any references to /dev/sdb or /mnt/chroot with grep for either
command. The journal says the umount was successful:
Jul 07 13:42:48 Mobile-PC sudo[3403]: gene : TTY=pts/0 ; PWD=/home/gene ;
USER=root ; COMMAND=/usr/bin/umount -v -R /mnt/chroot
Jul 07 13:42:48 Mobile-PC sudo[3403]: pam_unix(sudo:session): session opened
for user root(uid=0) by (uid=1000)
Jul 07 13:42:48 Mobile-PC sudo[3403]: pam_unix(sudo:session): session closed
for user root
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-kernel-security.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-kernel-config.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-fs-fuse-connections.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-kernel-tracing.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-kernel-debug.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-fs-bpf.mount: Deactivated
successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]:
mnt-chroot-sys-firmware-efi-efivars.mount: Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-fs-pstore.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys-fs-cgroup.mount:
Deactivated successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot-sys.mount: Deactivated
successfully.
Jul 07 13:42:48 Mobile-PC systemd[1]: mnt-chroot.mount: Deactivated
successfully.
Check out what happens when I run journalctl -f and umplug/replug the drive:
Jul 07 13:50:31 Mobile-PC kernel: usb 2-1: USB disconnect, device number 2
Jul 07 13:50:31 Mobile-PC systemd[1]: Stopping Sabrent-Samsung temperature
monitor daemon, started by udev rule...
Jul 07 13:50:31 Mobile-PC systemd[1]: Sabrent-Samsung-tempd.service:
Deactivated successfully.
Jul 07 13:50:31 Mobile-PC systemd[1]: Stopped Sabrent-Samsung temperature
monitor daemon, started by udev rule.
Jul 07 13:50:31 Mobile-PC systemd[1]: Sabrent-Samsung-tempd.service: Consumed
5.075s CPU time.
Jul 07 13:50:32 Mobile-PC kernel: sd 2:0:0:0: [sdb] Synchronizing SCSI cache
Jul 07 13:50:32 Mobile-PC kernel: sd 2:0:0:0: [sdb] Synchronize Cache(10)
failed: Result: hostbyte=DID_ERROR driverbyte=DRIVER_OK
Jul 07 13:50:38 Mobile-PC kernel: usb 2-1: new SuperSpeed Plus Gen 2x1 USB
device number 3 using xhci_hcd
Jul 07 13:50:38 Mobile-PC kernel: usb 2-1: New USB device found, idVendor=0bda,
idProduct=9210, bcdDevice=20.01
Jul 07 13:50:38 Mobile-PC kernel: usb 2-1: New USB device strings: Mfr=1,
Product=2, SerialNumber=3
Jul 07 13:50:38 Mobile-PC kernel: usb 2-1: Product: Sabrent
Jul 07 13:50:38 Mobile-PC kernel: usb 2-1: Manufacturer: Sabrent
Jul 07 13:50:38 Mobile-PC kernel: usb 2-1: SerialNumber: 012345678930
Jul 07 13:50:38 Mobile-PC kernel: scsi host3: uas
Jul 07 13:50:38 Mobile-PC mtp-probe[4457]: checking bus 2, device 3:
"/sys/devices/pci0000:00/0000:00:08.1/0000:03:00.3/usb2/2-1"
Jul 07 13:50:38 Mobile-PC mtp-probe[4457]: bus: 2, device: 3 was not an MTP
device
Jul 07 13:50:38 Mobile-PC kernel: scsi 3:0:0:0: Direct-Access Sabrent
1.00 PQ: 0 ANSI: 6
Jul 07 13:50:38 Mobile-PC mtp-probe[4458]: checking bus 2, device 3:
"/sys/devices/pci0000:00/0000:00:08.1/0000:03:00.3/usb2/2-1"
Jul 07 13:50:38 Mobile-PC mtp-probe[4458]: bus: 2, device: 3 was not an MTP
device
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: Attached scsi generic sg1 type 0
Jul 07 13:50:38 Mobile-PC systemd[1]: Started Sabrent-Samsung temperature
monitor daemon, started by udev rule.
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: [sdc] 1000215216 512-byte logical
blocks: (512 GB/477 GiB)
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: [sdc] Write Protect is off
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: [sdc] Mode Sense: 37 00 00 08
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: [sdc] Write cache: enabled, read
cache: enabled, doesn't support DPO or FUA
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: [sdc] Optimal transfer size
33553920 bytes
Jul 07 13:50:38 Mobile-PC kernel: sdc: sdc1 sdc2
Jul 07 13:50:38 Mobile-PC kernel: sd 3:0:0:0: [sdc] Attached SCSI disk
Jul 07 13:50:38 Mobile-PC kernel: BTRFS warning: duplicate device /dev/sdc2
devid 1 generation 6733 scanned by systemd-udevd (4456)
Notice that it reattached as /dev/sdc2. I get the same message when the mount
fails:
Jul 07 13:52:20 Mobile-PC sudo[4716]: gene : TTY=pts/1 ; PWD=/home/gene ;
USER=root ; COMMAND=/usr/bin/mount -v UUID=4c96a0c2-f72f-4827-b023-83ba000b2fd2
/mnt/chroot
Jul 07 13:52:20 Mobile-PC kernel: BTRFS warning: duplicate device /dev/sdc2
devid 1 generation 6733 scanned by mount (4717)
Jul 07 13:52:20 Mobile-PC sudo[4716]: pam_unix(sudo:session): session opened
for user root(uid=0) by (uid=1000)
Jul 07 13:52:20 Mobile-PC sudo[4716]: pam_unix(sudo:session): session closed
for user root
Let me know if you need more info.
An aside, this only seems to happen for --rbind and --make-rslave. Just
mounting the root drive doesn't cause a problem.
Thanks,
Gene