Kernel metadata scrubbing facility is not available.

[bjo]

Running xfs_scrub leads to an error:

sudo xfs_scrub /
EXPERIMENTAL xfs_scrub program in use! Use at your own risk!
Info: /: Kernel metadata scrubbing facility is not available.
Info: /: Scrub aborted after phase 1.
/: errors found: 1

Expected behaviour:
xfs_scrub can srub the XFS filesystems.

xfs_info /
meta-data=/dev/mapper/sda5_crypt isize=512 agcount=4, agsize=7767424 blks
         = sectsz=512 attr=2, projid32bit=1
         = crc=1 finobt=1 spinodes=0 rmapbt=0
         = reflink=0
data = bsize=4096 blocks=31069696, imaxpct=25
         = sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=15170, version=2
         = sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

Ubuntu Version:
Description: Ubuntu 18.10
Release: 18.10

related packages:
linux-generic:
  Installed: 4.18.0.13.14
  Candidate: 4.18.0.13.14
  Version table:
 *** 4.18.0.13.14 500
        500 http://ftp.halifax.rwth-aachen.de/ubuntu cosmic-updates/main amd64 Packages
        500 http://ftp.halifax.rwth-aachen.de/ubuntu cosmic-security/main amd64 Packages
        500 http://ftp.halifax.rwth-aachen.de/ubuntu cosmic-proposed/main amd64 Packages
        100 /var/lib/dpkg/status
     4.18.0.10.11 500
        500 http://ftp.halifax.rwth-aachen.de/ubuntu cosmic/main amd64 Packages
xfsprogs:
  Installed: 4.15.1-1ubuntu1
  Candidate: 4.15.1-1ubuntu1
  Version table:
 *** 4.15.1-1ubuntu1 500
        500 http://ftp.halifax.rwth-aachen.de/ubuntu cosmic/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 18.10
Package: linux-image-4.18.0-10-generic 4.18.0-10.11
ProcVersionSignature: Ubuntu 4.18.0-10.11-generic 4.18.12
Uname: Linux 4.18.0-10-generic x86_64
ApportVersion: 2.20.10-0ubuntu13.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC0: bfr 2664 F.... pulseaudio
CurrentDesktop: XFCE
Date: Wed Jan 2 12:50:13 2019
MachineType: LENOVO 2325G70
ProcFB: 0 inteldrmfb
ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-4.18.0-10-generic root=UUID=0bc0ece5-9967-416c-9c82-1dae5051f2c8 ro splash quiet vt.handoff=1
RelatedPackageVersions:
 linux-restricted-modules-4.18.0-10-generic N/A
 linux-backports-modules-4.18.0-10-generic N/A
 linux-firmware 1.175.1
SourcePackage: linux
UpgradeStatus: Upgraded to cosmic on 2018-10-21 (72 days ago)
dmi.bios.date: 06/19/2018
dmi.bios.vendor: LENOVO
dmi.bios.version: G2ETB3WW (2.73 )
dmi.board.asset.tag: Not Available
dmi.board.name: 2325G70
dmi.board.vendor: LENOVO
dmi.board.version: Not Defined
dmi.chassis.asset.tag: PK1R41C
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Not Available
dmi.modalias: dmi:bvnLENOVO:bvrG2ETB3WW(2.73):bd06/19/2018:svnLENOVO:pn2325G70:pvrThinkPadX230:rvnLENOVO:rn2325G70:rvrNotDefined:cvnLENOVO:ct10:cvrNotAvailable:
dmi.product.family: ThinkPad X230
dmi.product.name: 2325G70
dmi.product.sku: LENOVO_MT_2325
dmi.product.version: ThinkPad X230
dmi.sys.vendor: LENOVO

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

This change was made by a bot.

[BA (ba9999)]

Needs CONFIG_XFS_ONLINE_SCRUB (4.15–4.20, 5.0–5.18, 5.19-rc+HEAD)

Due to the currently experimental nature of this xfs_scrub{,_all} should probably be opt-in with something like /etc/xfs_scrub.conf similar to /etc/e2scrub.conf.

Without it, xfs_scrub_all doesn't appear to do anything useful:

Scrubbing /var/lib/plexmediaserver...
Scrubbing /ext...
Scrubbing /tank...
Starting Online XFS Metadata Check for /ext...
Starting Online XFS Metadata Check for /tank...
Starting Online XFS Metadata Check for /var/lib/plexmediaserver...
Error: /ext: Kernel metadata scrubbing facility is not available.
EXPERIMENTAL xfs_scrub program in use! Use at your own risk!
Info: /ext: Scrub aborted after phase 1.
/ext: operational errors found: 1
Error: /tank: Kernel metadata scrubbing facility is not available.
EXPERIMENTAL xfs_scrub program in use! Use at your own risk!
Info: /tank: Scrub aborted after phase 1.
/tank: operational errors found: 1
Error: /var/lib/plexmediaserver: Kernel metadata scrubbing facility is not available.
EXPERIMENTAL xfs_scrub program in use! Use at your own risk!
Info: /var/lib/plexmediaserver: Scrub aborted after phase 1.
/var/lib/plexmediaserver: operational errors found: 1
Scrubbing /ext done, (err=0)
Scrubbing /tank done, (err=0)
Scrubbing /var/lib/plexmediaserver done, (err=0)

PS: xfs_fsr should be on a similar timer (idle priority and not on battery power), kicked off to online "defrag" reorganize desired XFS volume(s). System volumes (low churn areas) don't benefit from xfs_fsr while high churn user volumes do.