** Description changed: I was testing how LXC runs a vivid systemd container on a vivid systemd host and occasionally ended up with the container init getting stuck in Ds state. + More specific: I was testing out some ansible playbooks on the + container, and in most (acutally all IIRC) cases the freeze would happen + when ansible tried to install a package with apt in the container. + As this was happening rather frequently, I ended up stracing the container systemd, which resulted in: open("/sys/fs/cgroup/systemd/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_RDONLY|O_CLOEXEC) = 16 - fstat(16, {st_mode=S_IFREG|0644, st_size=63, ...}) = 0 + fstat(16, {st_mode=S_IFREG|0644, st_size=63, ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f350bdd0000 read(16, "5337\n5339\n5978\n5980\n5981\n5982\n59"..., 4096) = 62 - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) - access("/sys/fs/cgroup/devices", F_OK) = 0 - open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) + access("/sys/fs/cgroup/devices", F_OK) = 0 + open("/sys/fs/cgroup/devices/lxc/test-cont/system.slice/ssh.service/cgroup.procs", O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC, 0666) = -1 ENOENT (No such file or directory) read(16, fd 16: lr-x------ 1 root root 64 Mar 7 18:37 16 -> /sys/fs/cgroup/systemd/lxc/test-cont/system.slice/ssh.service/cgroup.procs Next I noticed the bash autocompletion freezing on /var/lib on the host, so I tried to ls /var/lib which froze too. Attaching strace on ls caused: ls: cannot access /var/lib/lxcfs: Interrupted system call running lxcfs processes: root 759 0.6 0.0 22052 2748 ? Ss 15:31 1:16 /usr/bin/lxcfs -f -s -o allow_other /var/lib/lxcfs/ root 6541 0.0 0.0 22052 448 ? S 18:30 0:00 /usr/bin/lxcfs -f -s -o allow_other /var/lib/lxcfs/ root 6543 0.0 0.0 22052 448 ? S 18:30 0:00 /usr/bin/lxcfs -f -s -o allow_other /var/lib/lxcfs/ attaching strace to them showed: - 759: wait4(6541, - 6541: wait4(6543, + 759: wait4(6541, + 6541: wait4(6543, 6543: recvmsg(5, fd5: lrwx------ 1 root root 64 Mar 7 19:01 5 -> socket:[2082333] netstat: unix 3 [ ] DGRAM 2082333 - @0572f here I ran out of debugging ideas and decided to SIGKILL 6543, which unfroze the container. ProblemType: Bug DistroRelease: Ubuntu 15.04 Package: lxcfs 0.6-0ubuntu2 Uname: Linux 3.19.0-031900rc7-generic x86_64 ApportVersion: 2.16.2-0ubuntu1 Architecture: amd64 Date: Sat Mar 7 19:44:18 2015 EcryptfsInUse: Yes ProcEnviron: - TERM=screen - PATH=(custom, no user) - LANG=de_DE.UTF-8 - LANGUAGE=en_US.UTF-8 - SHELL=/bin/bash + TERM=screen + PATH=(custom, no user) + LANG=de_DE.UTF-8 + LANGUAGE=en_US.UTF-8 + SHELL=/bin/bash SourcePackage: lxcfs UpgradeStatus: Upgraded to vivid on 2013-03-06 (731 days ago)
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1429442 Title: lxcfs can freeze systemd in a container To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/lxcfs/+bug/1429442/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs