Bug #742

umount problems with multiple mounts

Added by corecode about 7 years ago. Updated 5 months ago.

Status:In ProgressStart date:
Priority:NormalDue date:
Assignee:tuxillo% Done:

0%

Category:Userland
Target version:3.8.0

Description

hey,

yes, my fault, but:

%mount
/dev/ad6s1a on / (ufs, local, soft-updates)
/dev/ad6s1b on /pbulk (ufs, local, soft-updates)
/ on /pbulk/clients/labospc67_1/root (null, local, read-only)
/pbulk/clients/labospc67_1/var on /pbulk/clients/labospc67_1/root/var (null, local)
/pbulk/clients/labospc67_1/tmp on /pbulk/clients/labospc67_1/root/tmp (null, local)
/pbulk/clients/labospc67_1/dev on /pbulk/clients/labospc67_1/root/dev (null, local)
/ on /pbulk/clients/labospc67_1/root (null, local, read-only)

%umount labospc67_1/root
umount: unmount of /pbulk/clients/labospc67_1/root failed: Device busy

%umount /pbulk/clients/labospc67_1/root/var
umount: unmount of /pbulk/clients/labospc67_1/root/var failed: Invalid argument

something is wrong here. i guess I can't umount the "upper" root mount, because it takes the "lower" root mount first. dito for the subdirs.

cheers
simon

History

#1 Updated by tuxillo 5 months ago

  • Description updated (diff)
  • Category set to Userland
  • Status changed from New to Feedback
  • Assignee deleted (0)
  • Priority changed from High to Normal
  • Target version set to 3.8.0

Hi,

I've tried to reproduced it with a similar mount setup but all went fine:

# df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/vkd0s1a 2.0G 1.1G 757M 59% /
devfs 1.0K 1.0K 0B 100% /dev
procfs 4.0K 4.0K 0B 100% /proc
/ 2.0G 1.1G 757M 59% /mnt
/var 2.0G 1.1G 757M 59% /mnt/var
/usr 2.0G 1.1G 757M 59% /mnt/usr
# mount
/dev/vkd0s1a on / (ufs, local)
devfs on /dev (devfs, local)
procfs on /proc (procfs, local)
/ on /mnt (null, local)
/var on /mnt/var (null)
/usr on /mnt/usr (null)
# umount /mnt
unmount(/mnt): Cannot unmount: 3 mount refs still present
umount: unmount of /mnt failed: Device busy
# umount /mnt/var
# umount /mnt/usr
# umount /mnt
# df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/vkd0s1a 2.0G 1.1G 757M 59% /
devfs 1.0K 1.0K 0B 100% /dev
procfs 4.0K 4.0K 0B 100% /proc

Cheers,
Antonio Huete

#2 Updated by tuxillo 5 months ago

  • Status changed from Feedback to In Progress
  • Assignee set to tuxillo

Hi,

corecode pointed out I was missing an additional mount_null / /mnt in my test. After doing that I can reproduce the issue:

# df -h
Filesystem Size Used Avail Capacity Mounted on
/dev/vkd0s1a 2.0G 1.3G 558M 70% /
devfs 1.0K 1.0K 0B 100% /dev
procfs 4.0K 4.0K 0B 100% /proc
/ 2.0G 1.3G 558M 70% /mnt
/var 2.0G 1.3G 558M 70% /mnt/var
/usr 2.0G 1.3G 558M 70% /mnt/usr
/ 2.0G 1.3G 558M 70% /mnt
# umount /mnt
unmount(0x8033214280): Cannot unmount: 2 mount refs still present
umount: unmount of /mnt failed: Device busy
# umount /mnt/var/
umount: unmount of /mnt/var failed: Invalid argument

Assigining this to myself.

Cheers,
Antonio Huete

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