Bug 1324670

Summary:	[4.4.6-301→4.5.0-302] BTRFS error (device dm-0): could not find root 8
Product:	[Fedora] Fedora	Reporter:	Christian Stadelmann <fedora>
Component:	kernel	Assignee:	Kernel Maintainer List <kernel-maint>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	24	CC:	fedora, gansalmon, itamar, jonathan, kernel-maint, madhu.chinakonda, mchehab
Target Milestone:	---
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-09-23 19:21:06 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Christian Stadelmann 2016-04-06 22:45:07 UTC

Version-Release number of selected component (if applicable):
4.5.0-302.fc24.x86_64
not affected: all F23 kernels up to 4.4.6-301

How reproducible:
on every boot on multiple systems with similar layout: / is a btrfs partition in a LUKS container on a SSD

Steps to Reproduce:
1. have a system with btrfs on a LUKS container
2. boot
3. watch kernel output, journalctl or dmesg

Actual results:
I'm seeing a scary error message:
`BTRFS error (device dm-0): could not find root 8`

Expected results:
No error message if nothing is wrong. In case something is wrong I 

Additional info:
See also: https://www.spinics.net/lists/linux-btrfs/msg49600.html – this looks like an unnecessary error message with nothing being wrong.

Comment 1 Josh Boyer 2016-04-11 14:53:40 UTC

This isn't a regression.  It is a new error message, and as you have pointed out you can ignore it.

Comment 2 Laura Abbott 2016-09-23 19:11:28 UTC

*********** MASS BUG UPDATE **************
 
We apologize for the inconvenience.  There is a large number of bugs to go through and several of them have gone stale.  Due to this, we are doing a mass bug update across all of the Fedora 24 kernel bugs.
 
Fedora 24 has now been rebased to 4.7.4-200.fc24.  Please test this kernel update (or newer) and let us know if you issue has been resolved or if it is still present with the newer kernel.
 
If you have moved on to Fedora 25, and are still experiencing this issue, please change the version to Fedora 25.
 
If you experience different issues, please open a new bug report for those.

Comment 3 Christian Stadelmann 2016-09-23 19:21:06 UTC

This issue is not present any more with 4.7.4 or newer. In fact it is gone since updating from 4.5.4-300.fc24.x86_64 to 4.5.5-300.fc24.x86_64.

See also: https://btrfs.wiki.kernel.org/index.php?title=Changelog#v4.6_.28May_2016.29 , probably packported to 4.5.4 from 4.6 release.