[CRIU] Fake mount points in dump

[Pavel Emelyanov]

On 01/19/2016 01:46 PM, Stanislav Kinsburskiy wrote:
> 
> 
> 18.01.2016 17:26, Pavel Emelyanov пишет:
>> On 01/18/2016 03:35 PM, Stanislav Kinsburskiy wrote:
>>> Hi,
>>>
>>> I'm trying to suspend a container with the following mount list in it:
>>>
>>> [root at centos-7-x86_64 ~]# cat /proc/mounts
>>> rootfs / rootfs rw 0 0
>>> /dev/ploop43992p1 / ext4 rw,relatime,data=ordered,balloon_ino=12 0 0
>>> none /sys sysfs rw,relatime,ve=102 0 0
>>> none /sys/fs/cgroup tmpfs rw,relatime,size=1931780k,nr_inodes=482945 0 0
>>> cgroup /sys/fs/cgroup/cpuset cgroup
>>> rw,nosuid,nodev,noexec,relatime,cpuset 0 0
>>> cgroup /sys/fs/cgroup/cpu,cpuacct cgroup
>>> rw,nosuid,nodev,noexec,relatime,cpuacct,cpu 0 0
>>> cgroup /sys/fs/cgroup/memory cgroup
>>> rw,nosuid,nodev,noexec,relatime,memory 0 0
>>> cgroup /sys/fs/cgroup/devices cgroup
>>> rw,nosuid,nodev,noexec,relatime,devices 0 0
>>> cgroup /sys/fs/cgroup/freezer cgroup
>>> rw,nosuid,nodev,noexec,relatime,freezer 0 0
>>> cgroup /sys/fs/cgroup/net_cls cgroup
>>> rw,nosuid,nodev,noexec,relatime,net_cls 0 0
>>> cgroup /sys/fs/cgroup/blkio cgroup rw,nosuid,nodev,noexec,relatime,blkio 0 0
>>> cgroup /sys/fs/cgroup/perf_event cgroup
>>> rw,nosuid,nodev,noexec,relatime,perf_event 0 0
>>> cgroup /sys/fs/cgroup/hugetlb cgroup
>>> rw,nosuid,nodev,noexec,relatime,hugetlb 0 0
>>> cgroup /sys/fs/cgroup/systemd cgroup
>>> rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd
>>> 0 0
>>> proc /proc proc rw,relatime 0 0
>>> devtmpfs /dev devtmpfs rw,nosuid,size=1931780k,nr_inodes=482945 0 0
>>> tmpfs /dev/shm tmpfs rw,nosuid,nodev 0 0
>>> devpts /dev/pts devpts
>>> rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0
>>> tmpfs /run tmpfs rw,nosuid,nodev,mode=755 0 0
>>> mqueue /dev/mqueue mqueue rw,relatime 0 0
>>> sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0
>>>
>>> and get the following error (persistent):
>>>
>>> (00.221054) mnt: <--
>>> (00.221489)     type proc source proc mnt_id 20 s_dev 0x3 / @ ./proc
>>> flags 0x30000e options
>>> (00.221651)     type sysfs source sysfs mnt_id 21 s_dev 0x13 / @ ./sys
>>> flags 0x30000e options
>>> (00.221754)     type devtmpfs source devtmpfs mnt_id 22 s_dev 0x5 / @
>>> ./dev flags 0x1100000 options size=1922508k,nr_inodes=480627,mode=755
>>> (00.221842)     type securityfs source securityfs mnt_id 23 s_dev 0x14 /
>>> @ ./sys/kernel/security flags 0x30000e options
>>> (00.221927)     type tmpfs source tmpfs mnt_id 24 s_dev 0x15 / @
>>> ./dev/shm flags 0x1100000 options
>>> (00.222015)     type devpts source devpts mnt_id 25 s_dev 0xb / @
>>> ./dev/pts flags 0x30000a options gid=5,mode=620,ptmxmode=000
>>> (00.222163)     type tmpfs source tmpfs mnt_id 26 s_dev 0x16 / @ ./run
>>> flags 0x1100000 options mode=755
>>> (00.222624)     type tmpfs source tmpfs mnt_id 27 s_dev 0x17 / @
>>> ./sys/fs/cgroup flags 0x1100000 options mode=755
>>> (00.222716)     type cgroup source cgroup mnt_id 28 s_dev 0x18 / @
>>> ./sys/fs/cgroup/systemd flags 0x30000e options
>>> xattr,release_agent=/usr/lib/systemd/systemd-cgroups-agent,name=systemd
>>> (00.222803)     type pstore source pstore mnt_id 29 s_dev 0x19 / @
>>> ./sys/fs/pstore flags 0x30000e options
>>> (00.222917)     type cgroup source cgroup mnt_id 30 s_dev 0x12 / @
>>> ./sys/fs/cgroup/cpuset flags 0x30000e options cpuset
>>> (00.223022)     type cgroup source cgroup mnt_id 31 s_dev 0x11 / @
>>> ./sys/fs/cgroup/cpu,cpuacct flags 0x30000e options cpuacct,cpu
>>> (00.223147)     type cgroup source cgroup mnt_id 32 s_dev 0xf / @
>>> ./sys/fs/cgroup/memory flags 0x30000e options memory
>>> (00.223303)     type cgroup source cgroup mnt_id 33 s_dev 0x1a / @
>>> ./sys/fs/cgroup/devices flags 0x30000e options devices
>>> (00.223425)     type cgroup source cgroup mnt_id 34 s_dev 0x1b / @
>>> ./sys/fs/cgroup/freezer flags 0x30000e options freezer
>>> (00.223514)     type cgroup source cgroup mnt_id 35 s_dev 0x1c / @
>>> ./sys/fs/cgroup/net_cls flags 0x30000e options net_cls
>>> (00.223602)     type cgroup source cgroup mnt_id 36 s_dev 0xe / @
>>> ./sys/fs/cgroup/blkio flags 0x30000e options blkio
>>> (00.223688)     type cgroup source cgroup mnt_id 37 s_dev 0x1d / @
>>> ./sys/fs/cgroup/perf_event flags 0x30000e options perf_event
>>> (00.223773)     type cgroup source cgroup mnt_id 38 s_dev 0x1e / @
>>> ./sys/fs/cgroup/hugetlb flags 0x30000e options hugetlb
>>> (00.223858)     type cgroup source cgroup mnt_id 39 s_dev 0x1f / @
>>> ./sys/fs/cgroup/ve flags 0x30000e options ve
>>> (00.224002)     type cgroup source cgroup mnt_id 40 s_dev 0x10 / @
>>> ./sys/fs/cgroup/beancounter flags 0x30000e options beancounter
>>> (00.224116)     type configfs source configfs mnt_id 43 s_dev 0x20 / @
>>> ./sys/kernel/config flags 0x300000 options
>>> (00.224274)     type ext4 source /dev/mapper/vz_skinsbursky--vz7-root
>>> mnt_id 44 s_dev 0xfd00001 / @ ./ flags 0x300000 options
>>> quota,usrquota,grpquota,data=ordered
>>> (00.224387)     type autofs source systemd-1 mnt_id 45 s_dev 0x21 / @
>>> ./proc/sys/fs/binfmt_misc flags 0x300000 options
>>> fd=32,pgrp=1,timeout=300,minproto=5,maxproto=5,direct
>>> (00.224485) Error (autofs.c:220): Failed to find pipe_ino option (old
>>> kernel?)
>>> (00.224565) Error (proc_parse.c:1385): Failed to parse FS specific data
>>> on ./proc/sys/fs/binfmt_misc
>>> (00.224686) Error (mount.c:1908): mnt: Can't parse 83507's mountinfo
>>> (00.224770) Error (mount.c:824): mnt: Failed to find criu pid's mount ns
>> This error only appear if you use --ext-mount-map auto, do you?
> 
> Yes, above is correct.
> What does it mean?

It means than any external bind-mounts are tried to get auto-resolved.
Your error means that either a) we don't have such, but they are erroneously
detected or b) we have such, they are auto-detected by parsing host's
mount points and latter contain unsupported entries. In the latter case
we can fix it by relaxing the requirement for host's mountpoints e.g.
we can ignore options, since we don't need them.

-- Pavel