system shutdown hangs if btrfs on file image (mounted via cifs) is mounted

[Karl-Philipp Richter]

This happens if the network connection already failed before the shutdown has been requested. `systemd` should get into state where it refuses to proceed in shutdown.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: systemd 219-7ubuntu6
Uname: Linux 4.1.0-040100-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: Unity
Date: Tue Jun 23 15:14:18 2015
InstallationDate: Installed on 2015-06-08 (15 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Release amd64 (20140417)
MachineType: LENOVO 20221
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.1.0-040100-generic root=UUID=d665563a-2f33-4d06-bf9c-6838fe5ae3e9 ro rootflags=subvol=ubuntu-main-root
SourcePackage: systemd
UpgradeStatus: Upgraded to vivid on 2015-06-09 (14 days ago)
dmi.bios.date: 07/12/2013
dmi.bios.vendor: LENOVO
dmi.bios.version: 71CN51WW(V1.21)
dmi.board.asset.tag: No Asset Tag
dmi.board.name: INVALID
dmi.board.vendor: LENOVO
dmi.board.version: 31900003WIN8 STD MLT
dmi.chassis.asset.tag: No Asset Tag
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Lenovo IdeaPad Z500 Touch
dmi.modalias: dmi:bvnLENOVO:bvr71CN51WW(V1.21):bd07/12/2013:svnLENOVO:pn20221:pvrLenovoIdeaPadZ500Touch:rvnLENOVO:rnINVALID:rvr31900003WIN8STDMLT:cvnLENOVO:ct10:cvrLenovoIdeaPadZ500Touch:
dmi.product.name: 20221
dmi.product.version: Lenovo IdeaPad Z500 Touch
dmi.sys.vendor: LENOVO

[Martin Pitt (pitti)]

Can you please get a journal from shutdown, as described in /usr/share/doc/systemd/README.Debian ? Once it hangs, switch to the debug shell, and do

  journalctl -ab > /root/journal.txt
  reboot -f

and then attach /root/journal.txt here. I suppose it's the "umount" which times out on the network file system. There is not much that we can do about it in systemd then (as it's umount itself which is hanging), but let's first confirm what is the actual problem here. Thanks!

[Launchpad Janitor (janitor)]

[Expired for systemd (Ubuntu) because there has been no activity for 60 days.]

[Karl-Philipp Richter (krichter722)]

I can only reach the `systemd` debug shell randomly, i.e. the system freezes either before I can press Ctrl+Alt+F9, right after it so that I can't run `journalctl -ab > /root/journal.txt` or right after running the command so that data isn't written to `/root/journal.txt` because the system can apparently only be rebooted with Ctrl+Alt+SysRq+b so that the data is never written to the filesystem (btrfs).

After 5 failures at different states I couldn't recognize any pattern which causes the freeze. The start of debugging shell works consistently well if the btrfs image isn't mounted.

[Dan Streetman (ddstreet)]

please reopen if this is still an issue