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Date: Wed, 25 Mar 2015 01:42:35 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Kinglong Mee <kinglongmee@gmail.com>
Cc: Steve Dickson <SteveD@redhat.com>, rees@umich.edu,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH] blkmapd: Make sure device root contains valid device id
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On Sun, Mar 22, 2015 at 09:22:59PM +0800, Kinglong Mee wrote:
> When testing pnfs in virtual linux based on VirtualBox,
> blkmapd gets dev_root->len == 0, which causes it Segmentation fault.

VirtualBox learly returns bogus values here, but it's always better to
be defensive, so:

Reviewed-by: Christoph Hellwig <hch@lst.de>