[SOLVED] What is changed in mount options ?

gildbg · 02-18-2020, 02:03 AM

Hello,

here is a mount of my pc on slackware current update to latest:

/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
tmpfs on /dev/shm type tmpfs (rw)
tmpfs on /var/lib/php type tmpfs (rw,size=10m,uid=80,gid=80,mode=0755)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)

Well, I was having problem with hard drive, so I replace it and install new slackware-current. After I write mount, the out put seems different:

/dev/sda1 on / type ext4 (rw,relatime)
devtmpfs on /dev type devtmpfs (rw,relatime,size=2006580k,nr_inodes=501645,mode=755)
proc on /proc type proc (rw,relatime)
sysfs on /sys type sysfs (rw,relatime)
tmpfs on /run type tmpfs (rw,nosuid,nodev,noexec,relatime,size=32768k,mode=755)
devpts on /dev/pts type devpts (rw,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,noexec,relatime)
cgroup_root on /sys/fs/cgroup type tmpfs (rw,relatime,size=8192k,mode=755)
cpuset on /sys/fs/cgroup/cpuset type cgroup (rw,relatime,cpuset,clone_children)
cpu on /sys/fs/cgroup/cpu type cgroup (rw,relatime,cpu)
cpuacct on /sys/fs/cgroup/cpuacct type cgroup (rw,relatime,cpuacct)
blkio on /sys/fs/cgroup/blkio type cgroup (rw,relatime,blkio)
memory on /sys/fs/cgroup/memory type cgroup (rw,relatime,memory)
devices on /sys/fs/cgroup/devices type cgroup (rw,relatime,devices)
freezer on /sys/fs/cgroup/freezer type cgroup (rw,relatime,freezer)
net_cls on /sys/fs/cgroup/net_cls type cgroup (rw,relatime,net_cls)
perf_event on /sys/fs/cgroup/perf_event type cgroup (rw,relatime,perf_event)
net_prio on /sys/fs/cgroup/net_prio type cgroup (rw,relatime,net_prio)
pids on /sys/fs/cgroup/pids type cgroup (rw,relatime,pids)
tmpfs on /var/run type tmpfs (rw,nosuid,nodev,noexec,relatime,size=32768k,mode=755)

Both installations was current, but first update from slackware 14.2 to current over the years and for new installation I make a current iso and install it. I can't find from where changes is coming but other question also is rotate in my mind. If I update from 14.2 to current, why when I reboot old current instalation did not change the mounts and if slackpkg miss something, what else can miss ?

Thanks

rkelsen · 02-18-2020, 04:00 AM

The added mounts appear to be connected to cgroups.

Check to see if the /etc/rc.d/rc.cgmanager script is executable on both.

gildbg · 02-18-2020, 04:55 AM

That is the first thing that I check even compare the with md5sum for differences.
Both is the same, rc.cgconfig and rc.cgred isnt executable, rc.cgmanager and rc.cgproxy is executable.

ponce · 02-18-2020, 05:17 AM

the control groups filesystem interface is mounted in rc.S, in this block

Code:

# Mount Control Groups filesystem interface:
if grep -wq cgroup /proc/filesystems ; then
  if [ -d /sys/fs/cgroup ]; then
    # See linux-*/Documentation/cgroups/cgroups.txt (section 1.6)
    # Check if we have some tools to autodetect the available cgroup controllers
    if [ -x /bin/cut -a -x /bin/tail ]; then
      # Mount a tmpfs as the cgroup filesystem root
      mount -t tmpfs -o mode=0755,size=8M cgroup_root /sys/fs/cgroup
      # Autodetect available controllers and mount them in subfolders
      controllers="$(/bin/cut -f 1 /proc/cgroups | /bin/tail -n +2)"
      for i in $controllers; do
        mkdir /sys/fs/cgroup/$i
        mount -t cgroup -o $i $i /sys/fs/cgroup/$i
      done
      unset i controllers
    else
      # We can't use autodetection so fall back mounting them all together
      mount -t cgroup cgroup /sys/fs/cgroup
    fi
  else
    mkdir -p /dev/cgroup
    mount -t cgroup cgroup /dev/cgroup
  fi
fi

that is actually there (with some edits during time) since Slackware 14.1 rc1: from the ChangeLog

Code:

Mon Oct 14 22:09:17 UTC 2013
And with this batch of updates and fixes (clearing the rest of the
important stuff from the TODO list), we have arrived at Slackware 14.1
release candidate 1!  Please test and report any remaining issues.
[...]
a/sysvinit-scripts-2.0-noarch-16.txz:  Rebuilt.
  Clean up stale cron directories in /var/spool/cron.
  Create lock/run directories for LVM.
  Thanks to GazL.
  Mount cgroup controllers in subfolders.
  Thanks to Matteo Bernardini.

rworkman · 02-18-2020, 08:01 PM

I'd be willing to bet that your /etc/mtab was an actual file before (supported the old mount binary) while the new one defaults to /etc/mtab being a symlink to /proc/mounts, which supports the new mount binary. This results in quite a bit of new/different information shown.

gildbg · 02-19-2020, 03:30 AM

Ah yes, it's seems that is the problem.

volkerdi · 02-20-2020, 04:19 PM

Quote:

Originally Posted by gildbg

Ah yes, it's seems that is the problem.

This is exactly why I stuck with a real /etc/mtab for so long, but increasingly it was causing issues elsewhere and it was time to stop swimming upstream on this one.