From mboxrd@z Thu Jan  1 00:00:00 1970
From: Zefan Li <lizefan@huawei.com>
Subject: Re: "don't bugger nd->seq" seems to break umount
	sometimes
Date: Thu, 30 Apr 2015 09:15:05 +0800
Message-ID: <55418219.8080700@huawei.com>
References: <E1YleTb-0005Ma-NN@osstest.test-lab.xenproject.org>
	<21824.50281.405589.957467@mariner.uk.xensource.com>
	<20150429122139.GN889@ZenIV.linux.org.uk>
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To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: xen-tools@packages.debian.org, xen-devel@lists.xensource.com, Andrew Cooper <andrew.cooper3@citrix.com>, stefano.stabellini@eu.citrix.com, Ian Jackson <Ian.Jackson@eu.citrix.com>, David Vrabel <david.vrabel@citrix.com>, Boris Ostrovsky <boris.ostrovsky@oracle.com>
List-Id: xen-devel@lists.xenproject.org

On 2015/4/29 20:21, Al Viro wrote:
> On Wed, Apr 29, 2015 at 12:45:45PM +0100, Ian Jackson wrote:
> 
>> The symptoms are that `umount' fails with EBUSY,
> 
>     [lizf: Backported to 3.4:
>      - remove the changes to follow_link() as it doesn't call set_root()]
> 
> looks dubious - I don't have -stable in front of me, but set_root() in
> follow_link() had migrated from __vfs_follow_link(), so could you try
> (tr '#' '\t' | ed fs/namei.c) <<'EOF'
> /__vfs_follow_link/
> /set_root/s/^/#/
> i
> ##if (!nd->root.mnt)
> .
> wq
> EOF
> and see if it helps?
> .
> 

My fault. I just checked 3.2.y, and it made the right change.