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Date: Sun, 24 Jul 2016 01:22:06 +0100
From: Al Viro <viro@ZenIV.linux.org.uk>
To: "J. Bruce Fields" <bfields@redhat.com>
Cc: Oleg Drokin <green@linuxhacker.ru>, Jeff Layton <jlayton@poochiereds.net>,
        linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        "J. Bruce Fields" <bfields@fieldses.org>
Subject: Re: [PATCH 3/7] nfsd: remove redundant i_lookup check
Message-ID: <20160724002152.GN2356@ZenIV.linux.org.uk>
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On Fri, Jul 22, 2016 at 01:48:52PM -0400, J. Bruce Fields wrote:
> From: "J. Bruce Fields" <bfields@redhat.com>
> 
> I'm not sure why this was added.  It doesn't seem necessary, and no
> other caller does this.

lookup_one_len() will explode if you call it for non-directory (==
!d_can_lookup(), i.e. something without ->lookup()).  So unless the callers
do guarantee that check being true, it *is* needed.