Leftover mount in /etc/mtab pointing to /var/lib/ureadahead/debugfs/tracing after some runs of apt dist-upgrade followed by a reboot
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
ureadahead (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned |
Bug Description
After a patching and a reboot cycle (possibly only the ones that involve running ureadahead triggers) a leftover mount entry is present in /etc/mtab pointing to /var/lib/
root@localhost:~$ mount
/dev/
proc on /proc type proc (rw,noexec,
sysfs on /sys type sysfs (rw,noexec,
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,
tmpfs on /run type tmpfs (rw,noexec,
none on /run/lock type tmpfs (rw,noexec,
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,
none on /sys/fs/pstore type pstore (rw)
tracefs on /var/lib/
/dev/sda1 on /boot type ext4 (rw)
systemd on /sys/fs/
root@localhost:~$ mount | grep tracefs
tracefs on /var/lib/
But that mount point doesn't exist
root@localhost:~$ ls -lha /var/lib/
total 8.0K
drwxr-xr-x 2 root root 4.0K Jan 27 11:36 .
drwxr-xr-x 3 root root 4.0K Jan 27 11:16 ..
That mtab entry can be removed by running 'umount /var/lib/
root@localhost:~$ mkdir /var/lib/
root@localhost:~$ ls -lh /var/lib/
total 4.0K
drwxr-xr-x 2 root root 4.0K Jan 27 11:28 tracing
root@localhost:~$ umount /var/lib/
umount: /var/lib/
root@localhost:~$ mount | grep tracefs
root@localhost:~$ mount
/dev/
proc on /proc type proc (rw,noexec,
sysfs on /sys type sysfs (rw,noexec,
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,
tmpfs on /run type tmpfs (rw,noexec,
none on /run/lock type tmpfs (rw,noexec,
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,
none on /sys/fs/pstore type pstore (rw)
/dev/sda1 on /boot type ext4 (rw)
systemd on /sys/fs/
I'm experiencing this on several Ubuntu 14.04 servers, running on a VMware cluster.
Package versions worth noting are:
ureadahead 0.100.0-16
linux-image-
open-vm-tools 2:9.4.0-
This also causes #1516451 and may be related to #499773
Just to note, 'mountall' also clears that mtab entry, but it also nukes contents of /tmp in the process, which might not be good if someone is running Passenger, which apparently keeps socket files in there (i.e. /tmp/passenger. 1.0.xxx/ generation- 0/request )