Bug 809502

Summary:	SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up()
Product:	Red Hat Enterprise Linux 5	Reporter:	Steve Dickson <steved>
Component:	kernel	Assignee:	nfs-maint
Status:	CLOSED DUPLICATE	QA Contact:	Filesystem QE <fs-qe>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	5.9	CC:	kzhang
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	809495	Environment:
Last Closed:	2012-04-04 17:21:46 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:	809495, 809928
Bug Blocks:

Description Steve Dickson 2012-04-03 14:34:08 UTC

+++ This bug was initially created as a clone of Bug #809495 +++

Description of problem:

    The problem is that for the case of priority queues, we
    have to assume that __rpc_remove_wait_queue_priority will move new
    elements from the tk_wait.links lists into the queue->tasks[] list.
    We therefore cannot use list_for_each_entry_safe() on queue->tasks[],
    since that will skip these new tasks that __rpc_remove_wait_queue_priority
    is adding.
    
    Without this fix, rpc_wake_up and rpc_wake_up_status will both fail
    to wake up all functions on priority wait queues, which can result
    in some nasty hangs.


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


How reproducible:
Sometimes 

Additional info:

Upstream commit:

commit 540a0f7584169651f485e8ab67461fcb06934e38
Author: Trond Myklebust <Trond.Myklebust>
Date:   Mon Mar 19 13:39:35 2012 -0400

    SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up()

Comment 1 RHEL Program Management 2012-04-03 14:39:36 UTC

This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux release.  Product Management has
requested further review of this request by Red Hat Engineering, for
potential inclusion in a Red Hat Enterprise Linux release for currently
deployed products.  This request is not yet committed for inclusion in
a release.

Comment 2 Steve Dickson 2012-04-04 17:21:46 UTC


*** This bug has been marked as a duplicate of bug 809937 ***