Comment 0 for bug 1837447

[Description]
In [1] two important fixes in BTRFS are listed:

8e928218780e2f1cf2f5891c7575e8f0b284fcce "btrfs: fix corruption reading shared and compressed extents after hole punching"

4ea748e1d2c9f8a27332b949e8210dbbf392987e "btrfs: fix deadlock between clone/dedupe and rename"

Both of them were backported to stable kernels like 4.14.x and newer 5.0 releases, but both are missisng in Ubuntu's 4.15.0 and 5.0.0.

[Impact]
Possible data corruption.

[Solution]
Cherry-pick those commits to supported kernels.

[1] https://github.com/Zygo/bees/blob/master/docs/btrfs-kernel.md

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: linux-image-generic 5.0.0.21.22
ProcVersionSignature: Ubuntu 5.0.0-21.22-generic 5.0.15
Uname: Linux 5.0.0-21-generic x86_64
ApportVersion: 2.20.10-0ubuntu27.1
Architecture: amd64
AudioDevicesInUse:
 USER PID ACCESS COMMAND
 /dev/snd/controlC1: user 2792 F.... pulseaudio
 /dev/snd/controlC2: user 2792 F.... pulseaudio
 /dev/snd/pcmC2D0p: user 2792 F...m pulseaudio
 /dev/snd/controlC0: user 2792 F.... pulseaudio
CurrentDesktop: XFCE
Date: Mon Jul 22 21:27:47 2019
HibernationDevice: #RESUME=UUID=0bc1a657-82ca-4015-971a-8c255c7889a9
InstallationDate: Installed on 2017-08-28 (693 days ago)
InstallationMedia: Xubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412)
MachineType: ASUS All Series
ProcFB: 0 radeondrmfb
ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-5.0.0-21-generic root=UUID=745b0c43-6a82-4bce-9821-7f5dd88a9246 ro rootflags=subvol=@ resume=UUID=133b8284-7ef8-4010-b2ea-b524bddea7e0
RelatedPackageVersions:
 linux-restricted-modules-5.0.0-21-generic N/A
 linux-backports-modules-5.0.0-21-generic N/A
 linux-firmware 1.178.4
RfKill:

SourcePackage: linux
UpgradeStatus: Upgraded to disco on 2018-02-08 (529 days ago)
dmi.bios.date: 03/10/2016
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 0801
dmi.board.asset.tag: To be filled by O.E.M.
dmi.board.name: AM1I-A
dmi.board.vendor: ASUSTeK COMPUTER INC.
dmi.board.version: Rev X.0x
dmi.chassis.asset.tag: Asset-1234567890
dmi.chassis.type: 3
dmi.chassis.vendor: Chassis Manufacture
dmi.chassis.version: Chassis Version
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr0801:bd03/10/2016:svnASUS:pnAllSeries:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnAM1I-A:rvrRevX.0x:cvnChassisManufacture:ct3:cvrChassisVersion:
dmi.product.family: ASUS MB
dmi.product.name: All Series
dmi.product.sku: All
dmi.product.version: System Version
dmi.sys.vendor: ASUS
modified.conffile..etc.default.apport: [modified]
mtime.conffile..etc.default.apport: 2018-07-03T12:21:32.224223