Mount structures are leaked

[Andrei Vagin]

Hello,

We found that mount structures are leaked on the upstream linux kernel:

[root@zdtm criu]# cat /proc/slabinfo | grep mnt
mnt_cache          36456  36456    384   42    4 : tunables    0    0
  0 : slabdata    868    868      0
[root@zdtm criu]#  python test/zdtm.py run  -t zdtm/static/env00
--iter 10 -f ns
=== Run 1/1 ================ zdtm/static/env00

========================= Run zdtm/static/env00 in ns ==========================
Start test
./env00 --pidfile=env00.pid --outfile=env00.out --envname=ENV_00_TEST
Run criu dump
Run criu restore
Run criu dump
....
Run criu restore
Send the 15 signal to  339
Wait for zdtm/static/env00(339) to die for 0.100000
Removing dump/zdtm/static/env00/31
========================= Test zdtm/static/env00 PASS ==========================
[root@zdtm criu]# cat /proc/slabinfo | grep mnt
mnt_cache          36834  36834    384   42    4 : tunables    0    0
  0 : slabdata    877    877      0

[root@zdtm linux]# git describe HEAD
v4.12-rc4-122-gb29794e

[root@zdtm ~]# uname -a
Linux zdtm.openvz.org 4.12.0-rc4+ #2 SMP Thu Jun 8 20:49:01 CEST 2017
x86_64 x86_64 x86_64 GNU/Linux

Thanks,
Andrei