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Date: Tue, 3 Feb 2009 16:26:43 +0100 (CET)
From: Martin Birgmeier <martin@email.aon.at>
Reply-To: Martin Birgmeier <martin@email.aon.at>
To: FreeBSD-gnats-submit@freebsd.org
Cc:
Subject: [nfs] mounting/unmounting of disks causes NFS to fail
X-Send-Pr-Version: 3.113
X-GNATS-Notify:

>Number:         131342
>Category:       kern
>Synopsis:       [nfs] mounting/unmounting of disks causes NFS to fail
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-fs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:  
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Tue Feb 03 15:30:05 UTC 2009
>Closed-Date:    
>Last-Modified:  Fri Jul  8 13:10:01 UTC 2011
>Originator:     Martin Birgmeier
>Release:        FreeBSD 7.1-RELEASE i386
>Organization:
MBi at home
>Environment:
System: FreeBSD gandalf.xyzzy 7.1-RELEASE FreeBSD 7.1-RELEASE #0: Sun Jan 4 10:53:24 CET 2009 root@atpcdvvc.xyzzy:/usr/VOL/OBJ/FreeBSD/RELENG_7_1_0_RELEASE/src/sys/XYZZY i386

>Description:
	[Please note that the email address given is not valid due to
	security reasons. Just reply to the gnats entry, and I'll follow
	it via the web interface.]

	Machine A is serving via NFS. When unmounting (probably also
	mounting) an unrelated file system on A, B will get a EPERM
	error if it is simultaneously accessing files on A via NFS.

	I have seen this behavior at least since 5.x, probably before.

>How-To-Repeat:
	Do heavy NFS i/o from machine B to machine A, then unmount (mount)
	a file system on A. B will get an error.

>Fix:
	Unknown.

>Release-Note:
>Audit-Trail:
Responsible-Changed-From-To: freebsd-bugs->freebsd-fs 
Responsible-Changed-By: linimon 
Responsible-Changed-When: Tue Feb 3 16:12:58 UTC 2009 
Responsible-Changed-Why:  
Over to maintainer(s). 

http://www.freebsd.org/cgi/query-pr.cgi?pr=131342 

From: Martin Birgmeier <Martin.Birgmeier@aon.at>
To: bug-followup@FreeBSD.org
Cc:  
Subject: Re: kern/131342: [nfs] mounting/unmounting of disks causes NFS to
 fail
Date: Fri, 08 Jul 2011 15:00:03 +0200

 This is a friendly reminder that some kind soul with knowledge of the 
 relevant kernel parts look into this... the error can easily be 
 reproduced. I just had it on a 7.4 system which did heavy reading from 
 an 8.2 server. When I mounted something on the server, the client got a 
 "Permission denied" reply.
 
 So, to recap the scenario:
 
 7.4 NFS client
 8.2 NFS server
 client mounts a fs from the server (via IPv4, might be interesting to 
 look at http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/151681, too, but 
 that is unrelated)
 client does heavy i/o on the mounted fs
 server does a mount (on its side, in this case it was from an md device)
 
 --> error: client gets back some NFS error (in this case "permission 
 denied")
 
>Unformatted:
