Bug 1291402

Summary:	FANOTIFY - Add patch for listening daemon's own opens to be pre-approved
Product:	Red Hat Enterprise Linux 7	Reporter:	Steve Grubb <sgrubb>
Component:	kernel	Assignee:	Eric Sandeen <esandeen>
kernel sub component:	File Systems - Other	QA Contact:	Murphy Zhou <xzhou>
Status:	CLOSED CANTFIX	Docs Contact:
Severity:	medium
Priority:	high	CC:	aviro, bressers, eguan, ikent, sgrubb, swhiteho
Version:	7.2
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-06-30 16:21:38 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:
Bug Depends On:
Bug Blocks:	1295577, 1296180, 1313485

Description Steve Grubb 2015-12-14 19:42:12 UTC

Description of problem:
If a daemon using FANOTIFY needs to open a file on a watched filesystem and
its wanting OPEN_PERM events, we get deadlock. (This could happen because
of a library the daemon is using suddenly decides it needs to look in a new
file.) 

Additional info:
Patch allowing this is posted upstream:
http://lkml.iu.edu/hypermail/linux/kernel/1510.1/03342.html

Comment 9 Eric Sandeen 2016-01-28 16:14:18 UTC

I sent a patch based on sgrubb's, moving "policy" to userspace at open time to fsdevel, and Jan Kara dumped cold water on that too.  As I am really not an expert in the subsystem or the usecase here, it'd be great to have sgrubb et al chime in with ideas and opinions on fsdevel...

Comment 10 Eric Sandeen 2016-06-30 16:18:03 UTC

This has never been agreed to or merged upstream, moving to 7.4 for now.

Comment 11 Steve Grubb 2016-06-30 16:21:38 UTC

This can actually be closed. I am making different plans to solve the problem. I do appreciate all the help on it.