Bug 617104 – unable to umount btrfs based filesystems

Bug 617104 - unable to umount btrfs based filesystems

Summary:	unable to umount btrfs based filesystems

Status:	CLOSED CURRENTRELEASE

Aliases:	None

Product:	Red Hat Enterprise Linux 6
Classification:	Red Hat
Component:	kernel (Show other bugs)
Sub Component:
Version:	6.0
Hardware:	x86_64 Linux

Priority	low Severity high
Target Milestone:	rc
Target Release:	---
Assigned To:	Josef Bacik
QA Contact:	Red Hat Kernel QE team
Docs Contact:

URL:
Whiteboard:
Keywords:

Depends On:
Blocks:
	Show dependency tree / graph

Reported:	2010-07-22 04:00 EDT by Lubos Kocman
Modified:	2010-08-30 11:01 EDT (History)
CC List:	3 users (show)

See Also:
Fixed In Version:
Doc Type:	Bug Fix
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2010-08-30 11:01:25 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
output of strace umount -f /home (5.97 KB, application/octet-stream) 2010-07-22 06:49 EDT, Lubos Kocman	no flags	Details
dmesg output taken after executing umount -f /home (73.41 KB, application/octet-stream) 2010-07-22 06:50 EDT, Lubos Kocman	no flags	Details
Add an attachment (proposed patch, testcase, etc.)

Groups: None (edit)

Description Lubos Kocman 2010-07-22 04:00:56 EDT

Description of problem:

I using RHEL6 (Clean install of RHEL6-20100715.x86_64 + updates) with btrfs / and /home.

In last few days I found out that halt is hanging on umount -f /home /boot.

So I tried out to umount filesystem from console (no process of lkocman should be running) manually but it failed.

I'm using following layout:

(T400 -- one disk)

rootvg ->
          lv_boot (ext4) /boot
          lv_root (btrfs) /
          lv_home (btrfs) /home -> 
                                  btrfs subvolume /home/lkocman

subvolume /home/lkocman contains also snapshots of /home/lkocman
         


Version-Release number of selected component (if applicable):

util-linux-ng-2.17.2-5.el6.x86_64
btrfs-progs-0.19-11.el6.x86_64
kernel-2.6.32-44.1.el6.x86_64


How reproducible:

Obtain machine with the same layout as I have

Steps to Reproduce:
1. umount -f /home
  
Actual results:

Hangs



Expected results:

Filesystem should be unmounted

Additional info:

Comment 2 Lubos Kocman 2010-07-22 06:49:19 EDT

Created attachment 433660 [details]
output of strace umount -f /home

umount -f /home is not hanging any more ... but it's showing that device is busy .... fuser /home is showing that no process is using /home

Comment 3 Lubos Kocman 2010-07-22 06:50:02 EDT

Created attachment 433661 [details]
dmesg output taken after executing umount -f /home

Comment 6 Lubos Kocman 2010-08-30 11:01:25 EDT

This problem no longer occur in 2.6.32-70.el6.x86_64. So I believe that it was fixed somewhere by upstream.

Closing as current-release

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