2365dd3ca02bbb6d3412404482e1d85752549953 in ubuntu_btrfs_kernel_fixes failed on B

[Po-Hsu Lin]

Test failed on Bionic, and this patch does exist in Bionic kernel tree.

Invoking test 2365dd3ca02bbb6d3412404482e1d85752549953

fix 2365dd3ca02bbb6d3412404482e1d85752549953

btrfs: undo sysfs when open_ctree() fails

    reproducer:
    mkfs.btrfs -f /dev/sdb && mount /dev/sdb /btrfs && btrfs dev add -f /dev/sdc /btrfs && umount /btrfs && wipefs -a /dev/sdc && mount -o degraded /dev/sdb /btrfs
    //above mount fails so try with RO
    mount -o degraded,ro /dev/sdb /btrfs

    ------
    sysfs: cannot create duplicate filename '/fs/btrfs/3f48c79e-5ed0-4e87-b189-86e749e503f4'
    ::

Performing full device TRIM /dev/loop1 (512.00MiB) ...
mount -o degraded /dev/loop0 /tmp/mnt-2365dd3ca02bbb6d3412404482e1d85752549953 was expected to fail

FAIL: 2365dd3ca02bbb6d3412404482e1d85752549953 (ret=1)

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-4.15.0-43-generic 4.15.0-43.46
ProcVersionSignature: User Name 4.15.0-43.46-generic 4.15.18
Uname: Linux 4.15.0-43-generic x86_64
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Dec 20 18:17 seq
 crw-rw---- 1 root audio 116, 33 Dec 20 18:17 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay'
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
CurrentDmesg:

Date: Thu Dec 27 07:34:54 2018
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig'
Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
PciMultimedia:

ProcFB: 0 cirrusdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-43-generic root=UUID=2f68c627-8ab4-40d5-8c06-6563436d0f96 ro console=ttyS0,115200n8
RelatedPackageVersions:
 linux-restricted-modules-4.15.0-43-generic N/A
 linux-backports-modules-4.15.0-43-generic N/A
 linux-firmware 1.173.2
RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/01/2014
dmi.bios.vendor: SeaBIOS
dmi.bios.version: Ubuntu-1.8.2-1ubuntu1
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-i440fx-xenial
dmi.modalias: dmi:bvnSeaBIOS:bvrUbuntu-1.8.2-1ubuntu1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-xenial:cvnQEMU:ct1:cvrpc-i440fx-xenial:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-xenial
dmi.sys.vendor: QEMU

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

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 1809870

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.

[Po-Hsu Lin (cypressyew)]

According to the btrfs document[1], adding another disk to the existing btrfs file system is equivalent to create a raid with Raid 1 on Meta, Raid 0 on Data group (mkfs.btrfs -m raid1 -d raid0).

So when wiping one of the disks out, it will corrupt the data but the meta should be OK:
# btrfs fi show
Label: none uuid: 3e7e0fb5-5fec-4938-bc20-0e5dfdf466ff
 Total devices 2 FS bytes used 128.00KiB
 devid 1 size 512.00MiB used 88.00MiB path /dev/loop0
 *** Some devices missing

This behaviour in this test case has been changed in the kernel with commit 4330e183c9537df20952d4a9ee142c536fb8ae54, we should be able to mount the drive with 'rw' in degraded mode, unless the data chunk was destroyed.

[1] https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices

[Po-Hsu Lin (cypressyew)]

https://kernel.ubuntu.com/git/ubuntu/autotest-client-tests.git/commit/?id=0bf2e4d2ff069e3cdd7e723361c8b28ea47a6508

Test blacklisted for newer kernel. (4330e183c9537df20952d4a9ee142c536fb8ae54 added for newer kernel)