I fail to understand why so many people are insisting this is a kernel bug. It isn't. What basically happens is that the network-manager process is not killed by killall5. This process also has an open file descriptor and therefore the root partitions cannot be mounted read-only before shutdown, as the kernel reports it is busy. Network-manager will not be killed due to the ubuntu patch add_sendsigs_omissions.patch, which was added to NM for a similar reason:
From: Mathieu Trudel-Lapierre <[email protected]> Subject: Move NM's spawns pid files to /run/sendsigs.omit.d. Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/869635 The pidfiles are only used by NM to start and be able to stop the same process, their actual location doesn't overly matter. In this case, putting them under /run/sendsigs.omit.d allows shutdown to skip over those as handled by an upstart job, and in fact they are (although indirectly). I have no idea what Mathieu actually intended with this patch, but it is entirely wrong and made everything worse. Instead of refusing to kill NM, it needs to be killed, which is just the other way around than what the patch is doing. The only way to fix this from kernel point of view would be to write a kernel patch to allow to mount read-only while there are still file descriptors, which have write access. All those FDs would need to be closed from the kernel side and propably would cause application crashes. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1073433 Title: Ext4 corruption associated with shutdown of Ubuntu 12.10 Status in Upstart: Confirmed Status in “linux” package in Ubuntu: Incomplete Status in “network-manager” package in Ubuntu: Triaged Status in “upstart” package in Ubuntu: Confirmed Bug description: 1. Format and label a target Ext4 partion using Ubuntu 12.04 2. Install 64bit 12.10 OS using that target without reformatting it 3. Shut down 4. Boot an alternate copy of Ubuntu 5. Restart selecting the newly installed OS 6. Login then shutdown 6. Boot an alternate copy of Ubuntu 7.Fsck the newly installed OS allowing corrections to be made Each time the the newly installed OS is executed and then shutdown, even if execution only consists of logging on, a subsequent fsck will FAIL. I used Acronis True Image Home 2013 to create an image of the newly installed 64-bit Ubuntu 12.10, so I can recreate the symptoms of Ext4 filesystem corruption 100% of the time by restoring from the image, booting, logging on and shutting down. ProblemType: Bug DistroRelease: Ubuntu 12.10 Package: linux-image-3.5.0-17-generic 3.5.0-17.28 ProcVersionSignature: Ubuntu 3.5.0-17.28-generic 3.5.5 Uname: Linux 3.5.0-17-generic x86_64 ApportVersion: 2.6.1-0ubuntu3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: aguru 1871 F.... pulseaudio /dev/snd/controlC0: aguru 1871 F.... pulseaudio CRDA: Error: command ['iw', 'reg', 'get'] failed with exit code 1: nl80211 not found. Date: Tue Oct 30 22:24:54 2012 HibernationDevice: RESUME=UUID=f22e3fa5-c5c5-41f1-ae5a-49390547cb67 InstallationMedia: Ubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.5) IwConfig: eth0 no wireless extensions. lo no wireless extensions. MachineType: System manufacturer P5Q-E ProcEnviron: PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 nouveaufb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.5.0-17-generic root=UUID=ef2c78d5-783a-422a-88f7-27ec09dda0d1 ro quiet splash vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-3.5.0-17-generic N/A linux-backports-modules-3.5.0-17-generic N/A linux-firmware 1.95 RfKill: SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/06/2009 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 2101 dmi.board.asset.tag: To Be Filled By O.E.M. dmi.board.name: P5Q-E dmi.board.vendor: ASUSTeK Computer INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2101:bd04/06/2009:svnSystemmanufacturer:pnP5Q-E:pvrSystemVersion:rvnASUSTeKComputerINC.:rnP5Q-E:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.name: P5Q-E dmi.product.version: System Version dmi.sys.vendor: System manufacturer To manage notifications about this bug go to: https://bugs.launchpad.net/upstart/+bug/1073433/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
