Current eoan v5.3.0 kernel has a much more strict tree checker for btrfs and may fail to mount the file system in case there are bad inode generations after an upgrade. This may be the case on file systems created before 2014.
A a result of failing to mount the user will land in the initramfs busybox. Manually trying to mount will display the failing inodes.
Unfortunately the built-in (in initramfs) btrfs checker from btrfs-progs 5.2.1 can not repair this problem.
That is related to this patch for btrfs-progs 5.3-rc1: https://<email address hidden>/T/#mfa319e441efe5a3b66955891ed61ed47e33bf543
As a work around after the upgrade the user should boot the old (disco) kernel and should be made aware not to remove this. As a more permanent resolution then linux-oem can be installed.
In principle a script can be devised to save the failing inodes with new, or when available btrfs-progs could be updated to 5.3 to repair the file system. In any case it should be considered that the failing inodes might be present on multiple snapshots of the fs.
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ProblemType: Bug
ApportVersion: 2.20.11-0ubuntu8
Architecture: amd64
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: ferry 2280 F.... pulseaudio
DistroRelease: Ubuntu 19.10
HibernationDevice: RESUME=UUID=72896b7c-29c8-4560-af37-7ebda2e01c1a
InstallationDate: Installed on 2012-11-19 (2526 days ago)
InstallationMedia: Kubuntu 12.10 "Quantal Quetzal" - Release amd64 (20121017.1)
IwConfig:
lo no wireless extensions.
eth1 no wireless extensions.
MachineType: To Be Filled By O.E.M. To Be Filled By O.E.M.
Package: linux (not installed)
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/@boot/vmlinuz-5.0.0-32-generic root=UUID=27155120-9ef8-47fb-b248-eaac2b7c8375 ro rootflags=subvol=@ quiet splash vt.handoff=7
ProcVersionSignature: Ubuntu 5.0.0-32.34-generic 5.0.21
RelatedPackageVersions:
linux-restricted-modules-5.0.0-32-generic N/A
linux-backports-modules-5.0.0-32-generic N/A
linux-firmware 1.183
RfKill:
Tags: eoan
Uname: Linux 5.0.0-32-generic x86_64
UpgradeStatus: Upgraded to eoan on 2019-10-18 (2 days ago)
UserGroups: adm cdrom dialout dip fax floppy lp lpadmin plugdev sambashare scanner sudo syslog wheel wireshark
_MarkForUpload: True
dmi.bios.date: 07/11/2013
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: P2.90
dmi.board.name: Z77 Extreme4
dmi.board.vendor: ASRock
dmi.chassis.asset.tag: To Be Filled By O.E.M.
dmi.chassis.type: 3
dmi.chassis.vendor: To Be Filled By O.E.M.
dmi.chassis.version: To Be Filled By O.E.M.
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvrP2.90:bd07/11/2013:svnToBeFilledByO.E.M.:pnToBeFilledByO.E.M.:pvrToBeFilledByO.E.M.:rvnASRock:rnZ77Extreme4:rvr:cvnToBeFilledByO.E.M.:ct3:cvrToBeFilledByO.E.M.:
dmi.product.family: To Be Filled By O.E.M.
dmi.product.name: To Be Filled By O.E.M.
dmi.product.sku: To Be Filled By O.E.M.
dmi.product.version: To Be Filled By O.E.M.
dmi.sys.vendor: To Be Filled By O.E.M.
This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1848935
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.