Bug#885325: Similar issue: Mount points not found by apache2 and another services

[Sumit Madan]

Dear Maintainer,

I've got a similar issue with mount points that are mounted manually 
after the boot process is completed. As John reports these mount points 
are not reachable anymore from other services. In his case smbd and in 
my case apache2 is affected.

I think the issue here is with the mount namespaces. The manually 
created mount points are only available in ssh mount namespace and not 
in others. On my device the services apache2 and /sbin/init have their 
own mount namespaces.

How to reproduce:
###
# login as user and then as root

# list of namespaces
$ lsns
         NS TYPE   NPROCS   PID USER  COMMAND
4026531835 cgroup    165     1 root  /sbin/init
4026531836 pid       165     1 root  /sbin/init
4026531837 user      165     1 root  /sbin/init
4026531838 uts       165     1 root  /sbin/init
4026531839 ipc       165     1 root  /sbin/init
4026531840 mnt       140     1 root  /sbin/init
4026531861 mnt         1    13 root  kdevtmpfs
4026531993 net       165     1 root  /sbin/init
4026532141 mnt         1   275 root /lib/systemd/systemd-udevd
4026532271 mnt         1  1546 ntp   /usr/sbin/ntpd -p /var/run/ntpd.pid 
-g -u 107:110
4026532275 mnt         1   830 redis /usr/bin/redis-server 127.0.0.1:6379
4026532276 mnt         1   820 mysql /usr/sbin/mysqld
4026532298 mnt         1 26730 root  /usr/sbin/sshd -D
4026532299 mnt         6 27541 root  /usr/sbin/apache2 -k start

# mount an external drive
$ mount /dev/1000GB-USB/owncloud /mnt/owncloud

$ cat /proc/self/mounts |grep owncloud
/dev/mapper/1000GB--USB-owncloud /mnt/owncloud ext4 
rw,relatime,data=ordered 0 0

$ cat /proc/27541/mounts |grep owncloud |wc -l
0

$ cat /proc/1/mounts |grep owncloud |wc -l
0
###

Do you have an idea how to propagate the mount points created in an ssh session to other namespaces? Why was it working before and not with the latest version?

-- 
Mit freundlichem Gruß / Best regards,

Sumit Madan