mount-ns test failing with latest bionic updates

[Sergio Cazzolato]

After the last refresh for bionic on gce the mount-ns test is failing with the error shown bellow.
Also are attached the diff for the bionic previous to the update and after the update.

Some usefull data:
---
image for spread.yaml: test-bionic-1
---
error link: https://travis-ci.org/snapcore/spread-cron/builds/610169331#L2487
---
error description:
2019-11-11 05:36:06 Error executing google:ubuntu-18.04-64:tests/main/mount-ns:inherit :
-----
+ '[' -e please-skip-this-test ']'
+ diff -u google.ubuntu-18.04-64/HOST.expected.txt HOST.deterministic.txt
--- google.ubuntu-18.04-64/HOST.expected.txt 2019-11-11 05:16:17.000000000 +0000
+++ HOST.deterministic.txt 2019-11-11 05:36:03.058621429 +0000
@@ -1,4 +1,4 @@
-0:0 / / rw,relatime shared:1 - ext4 /dev/sda1 rw,data=ordered
+0:0 / / rw,relatime shared:1 - ext4 /dev/sda1 rw
 0:1 / /boot/efi rw,relatime shared:2 - vfat /dev/sda15 rw,fmask=0022,dmask=0022,codepage=437,iocharset=iso8859-1,shortname=mixed,errors=remount-ro
 1:0 / /dev rw,nosuid,relatime shared:3 - devtmpfs udev rw,size=VARIABLE,nr_inodes=0,mode=755
 1:1 / /dev/hugepages rw,relatime shared:4 - hugetlbfs hugetlbfs rw,pagesize=2M
@@ -7,34 +7,33 @@
 1:4 / /dev/shm rw,nosuid,nodev shared:7 - tmpfs tmpfs rw
 1:5 / /proc rw,nosuid,nodev,noexec,relatime shared:8 - proc proc rw
 1:6 / /proc/fs/nfsd rw,relatime shared:9 - nfsd nfsd rw
-1:7 / /proc/sys/fs/binfmt_misc rw,relatime shared:10 - binfmt_misc binfmt_misc rw
-1:8 / /proc/sys/fs/binfmt_misc rw,relatime shared:11 - autofs systemd-1 rw,fd=0,pgrp=1,timeout=0,minproto=5,maxproto=5,direct,pipe_ino=0
-1:9 / /run rw,nosuid,noexec,relatime shared:12 - tmpfs tmpfs rw,size=VARIABLE,mode=755
-1:10 / /run/lock rw,nosuid,nodev,noexec,relatime shared:13 - tmpfs tmpfs rw,size=VARIABLE
-1:11 / /run/rpc_pipefs rw,relatime shared:14 - rpc_pipefs sunrpc rw
-1:12 / /run/user/0 rw,nosuid,nodev,relatime shared:15 - tmpfs tmpfs rw,size=VARIABLE,mode=700
-2:0 / /snap/core/1 ro,nodev,relatime shared:16 - squashfs /dev/loop0 ro
-2:1 / /snap/core18/1 ro,nodev,relatime shared:17 - squashfs /dev/loop1 ro
-2:2 / /snap/test-snapd-mountinfo-classic/1 ro,nodev,relatime shared:18 - squashfs /dev/loop2 ro
-2:3 / /snap/test-snapd-mountinfo-core16/1 ro,nodev,relatime shared:19 - squashfs /dev/loop3 ro
-2:4 / /snap/test-snapd-mountinfo-core18/1 ro,nodev,relatime shared:20 - squashfs /dev/loop4 ro
-1:13 / /sys rw,nosuid,nodev,noexec,relatime shared:21 - sysfs sysfs rw
-1:14 / /sys/fs/cgroup ro,nosuid,nodev,noexec shared:22 - tmpfs tmpfs ro,mode=755
-1:15 / /sys/fs/cgroup/blkio rw,nosuid,nodev,noexec,relatime shared:23 - cgroup cgroup rw,blkio
-1:16 / /sys/fs/cgroup/cpu,cpuacct rw,nosuid,nodev,noexec,relatime shared:24 - cgroup cgroup rw,cpu,cpuacct
-1:17 / /sys/fs/cgroup/cpuset rw,nosuid,nodev,noexec,relatime shared:25 - cgroup cgroup rw,cpuset
-1:18 / /sys/fs/cgroup/devices rw,nosuid,nodev,noexec,relatime shared:26 - cgroup cgroup rw,devices
-1:19 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime shared:27 - cgroup cgroup rw,freezer
-1:20 / /sys/fs/cgroup/hugetlb rw,nosuid,nodev,noexec,relatime shared:28 - cgroup cgroup rw,hugetlb
-1:21 / /sys/fs/cgroup/memory rw,nosuid,nodev,noexec,relatime shared:29 - cgroup cgroup rw,memory
-1:22 / /sys/fs/cgroup/net_cls,net_prio rw,nosuid,nodev,noexec,relatime shared:30 - cgroup cgroup rw,net_cls,net_prio
-1:23 / /sys/fs/cgroup/perf_event rw,nosuid,nodev,noexec,relatime shared:31 - cgroup cgroup rw,perf_event
-1:24 / /sys/fs/cgroup/pids rw,nosuid,nodev,noexec,relatime shared:32 - cgroup cgroup rw,pids
-1:25 / /sys/fs/cgroup/rdma rw,nosuid,nodev,noexec,relatime shared:33 - cgroup cgroup rw,rdma
-1:26 / /sys/fs/cgroup/systemd rw,nosuid,nodev,noexec,relatime shared:34 - cgroup cgroup rw,xattr,name=systemd
-1:27 / /sys/fs/cgroup/unified rw,nosuid,nodev,noexec,relatime shared:35 - cgroup2 cgroup rw,nsdelegate
-1:28 / /sys/fs/fuse/connections rw,relatime shared:36 - fusectl fusectl rw
-1:29 / /sys/fs/pstore rw,nosuid,nodev,noexec,relatime shared:37 - pstore pstore rw
-1:30 / /sys/kernel/config rw,relatime shared:38 - configfs configfs rw
-1:31 / /sys/kernel/debug rw,relatime shared:39 - debugfs debugfs rw
-1:32 / /sys/kernel/security rw,nosuid,nodev,noexec,relatime shared:40 - securityfs securityfs rw
+1:7 / /proc/sys/fs/binfmt_misc rw,nosuid,nodev,noexec,relatime shared:10 - binfmt_misc binfmt_misc rw
+1:8 / /run rw,nosuid,noexec,relatime shared:11 - tmpfs tmpfs rw,size=VARIABLE,mode=755
+1:9 / /run/lock rw,nosuid,nodev,noexec,relatime shared:12 - tmpfs tmpfs rw,size=VARIABLE
+1:10 / /run/rpc_pipefs rw,relatime shared:13 - rpc_pipefs sunrpc rw
+1:11 / /run/user/0 rw,nosuid,nodev,relatime shared:14 - tmpfs tmpfs rw,size=VARIABLE,mode=700
+2:0 / /snap/core/1 ro,nodev,relatime shared:15 - squashfs /dev/loop0 ro
+2:1 / /snap/core18/1 ro,nodev,relatime shared:16 - squashfs /dev/loop1 ro
+2:2 / /snap/test-snapd-mountinfo-classic/1 ro,nodev,relatime shared:17 - squashfs /dev/loop2 ro
+2:3 / /snap/test-snapd-mountinfo-core16/1 ro,nodev,relatime shared:18 - squashfs /dev/loop3 ro
+2:4 / /snap/test-snapd-mountinfo-core18/1 ro,nodev,relatime shared:19 - squashfs /dev/loop4 ro
+1:12 / /sys rw,nosuid,nodev,noexec,relatime shared:20 - sysfs sysfs rw
+1:13 / /sys/fs/cgroup ro,nosuid,nodev,noexec shared:21 - tmpfs tmpfs ro,mode=755
+1:14 / /sys/fs/cgroup/blkio rw,nosuid,nodev,noexec,relatime shared:22 - cgroup cgroup rw,blkio
+1:15 / /sys/fs/cgroup/cpu,cpuacct rw,nosuid,nodev,noexec,relatime shared:23 - cgroup cgroup rw,cpu,cpuacct
+1:16 / /sys/fs/cgroup/cpuset rw,nosuid,nodev,noexec,relatime shared:24 - cgroup cgroup rw,cpuset
+1:17 / /sys/fs/cgroup/devices rw,nosuid,nodev,noexec,relatime shared:25 - cgroup cgroup rw,devices
+1:18 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime shared:26 - cgroup cgroup rw,freezer
+1:19 / /sys/fs/cgroup/hugetlb rw,nosuid,nodev,noexec,relatime shared:27 - cgroup cgroup rw,hugetlb
+1:20 / /sys/fs/cgroup/memory rw,nosuid,nodev,noexec,relatime shared:28 - cgroup cgroup rw,memory
+1:21 / /sys/fs/cgroup/net_cls,net_prio rw,nosuid,nodev,noexec,relatime shared:29 - cgroup cgroup rw,net_cls,net_prio
+1:22 / /sys/fs/cgroup/perf_event rw,nosuid,nodev,noexec,relatime shared:30 - cgroup cgroup rw,perf_event
+1:23 / /sys/fs/cgroup/pids rw,nosuid,nodev,noexec,relatime shared:31 - cgroup cgroup rw,pids
+1:24 / /sys/fs/cgroup/rdma rw,nosuid,nodev,noexec,relatime shared:32 - cgroup cgroup rw,rdma
+1:25 / /sys/fs/cgroup/systemd rw,nosuid,nodev,noexec,relatime shared:33 - cgroup cgroup rw,xattr,name=systemd
+1:26 / /sys/fs/cgroup/unified rw,nosuid,nodev,noexec,relatime shared:34 - cgroup2 cgroup rw,nsdelegate
+1:27 / /sys/fs/fuse/connections rw,relatime shared:35 - fusectl fusectl rw
+1:28 / /sys/fs/pstore rw,nosuid,nodev,noexec,relatime shared:36 - pstore pstore rw
+1:29 / /sys/kernel/config rw,relatime shared:37 - configfs configfs rw
+1:30 / /sys/kernel/debug rw,relatime shared:38 - debugfs debugfs rw
+1:31 / /sys/kernel/security rw,nosuid,nodev,noexec,relatime shared:39 - securityfs securityfs rw
-----

[Maciej Borzecki (maciek-borzecki)]

+1:7 / /proc/sys/fs/binfmt_misc rw,nosuid,nodev,noexec,relatime shared:10 - binfmt_misc binfmt_misc rw

Did the mount options for the virtual filesystes change in the latest bionic?

[Paweł Stołowski (stolowski)]

They did (e.g. data=ordered is gone), plus an entry for systemd is gone, affecting lots of entries (indices changed by 1). I'm on it.

[Paweł Stołowski (stolowski)]

The changes are caused by kernel 5.0. PR: https://github.com/snapcore/snapd/pull/7756