Bug 1191236

Summary:	'umount -f' calls readlink on dead NFS mounts and hangs
Product:	Red Hat Enterprise Linux 6	Reporter:	Rachel Kroll <rkroll>
Component:	util-linux-ng	Assignee:	Karel Zak <kzak>
Status:	CLOSED ERRATA	QA Contact:	Tomas Dolezal <todoleza>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	6.4	CC:	kzak, phil, psklenar, todoleza
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	util-linux-ng-2.17.2-12.19.el6	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-05-11 00:34:49 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:
Embargoed:

Description Rachel Kroll 2015-02-10 19:28:02 UTC

Description of problem:

'umount -f', if intended as a quick way to umount2(..., MNT_FORCE), does not work in practice since it does other things to the mount point first.  This can make it hang (like the other broken things which made the user try umount -f in the first place).

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


How reproducible:


Steps to Reproduce:
1. Mount filesystem over NFS 
2. Break it somehow
3. Try umount -f, notice it stuck in readlink()

Actual results:

Very long delay, if it works at all.

Expected results:

Fast umount.

Additional info:

Comment 12 errata-xmlrpc 2016-05-11 00:34:49 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-0911.html