Bug 29980

Summary:	[bug]: Linux 5.16 has a major regression in btrfs causing extreme SSD/HDD stress!
Product:	Mageia	Reporter:	Nikolay Sabelnikov <79625490833>
Component:	RPM Packages	Assignee:	Kernel and Drivers maintainers <kernel>
Status:	RESOLVED FIXED	QA Contact:
Severity:	critical
Priority:	Normal	CC:	79625490833
Version:	Cauldron
Target Milestone:	---
Hardware:	All
OS:	Linux
URL:	https://lore.kernel.org/linux-btrfs/CAEwRaO4y3PPPUdwYjNDoB9m9CLzfd3DFFk2iK1X6OyyEWG5-mg@mail.gmail.com/
Whiteboard:
Source RPM:	kernel-5.16.*	CVE:
Status comment:

Description Nikolay Sabelnikov 2022-02-01 08:10:00 CET

Linux 5.16 saw some changes to the btrfs defragmentation code that introduced a regression causing extreme write I/O (and the associated single-core 100% CPU usage by a kernel thread named btrfs-cleaner).  Obviously, this is defragmentation in an endless loop.

 This affects volumes mounted with -ossd, autodefrag in fstab, which is the default on most distributions.

 Check if your distribution has this option and we recommend that you remove this flag for a while if you have a Linux 5.16.x kernel!

Nikolay Sabelnikov 2022-02-01 08:10:09 CET

CC: (none) => 79625490833

Nikolay Sabelnikov 2022-02-01 11:38:23 CET

Source RPM: Btrfs-cleaner => linux-btrfs

Nikolay Sabelnikov 2022-02-01 14:58:40 CET

Source RPM: linux-btrfs => kernel-516.*

Nikolay Sabelnikov 2022-02-01 14:58:49 CET

Source RPM: kernel-516.* => kernel-5.16.*

Comment 1 Lewis Smith 2022-02-01 20:12:11 CET

Thank you for the report.

I can do no more than assign this to the kernel team.

Assignee: bugsquad => kernel

Comment 2 Thomas Backlund 2022-02-01 21:45:47 CET

Fixed in 5.16.5 currently building

Resolution: (none) => FIXED
Status: NEW => RESOLVED

Comment 3 Thomas Backlund 2022-02-01 21:55:24 CET

actually... I had the fixes already in 5.16.4-2 :)