From: "Benjamin Coddington" <bcodding@redhat.com>
To: "List Linux NFS Mailing" <linux-nfs@vger.kernel.org>
Subject: I can't get no readdir satisfaction
Date: Tue, 23 Aug 2016 11:09:37 -0400
Message-ID: <778246F3-8F24-48FD-AEA9-0BCC0DCD93B3@redhat.com>
MIME-Version: 1.0
Sender: linux-nfs-owner@vger.kernel.org

Hi linux-nfs,

311324ad1713 ("NFS: Be more aggressive in using readdirplus for 'ls -l'
situations") changed when nfs_readdir() decides to revalidate the
directory's mapping, which contains all the entries.  In addition to just
checking if the attribute cache has expired, it includes a check to see if
NFS_INO_INVALID_DATA is set on the directory.

Well, customers that have directories with very many dentries and that same
directory's attributes are frequently updated are now grouchy that `ls -l`
takes so long since any update of the directory causes the mapping to be
invalidated and we have to start over filling the directory's mapping.

I actually haven't put real hard thought into it yet (because often for me
that just wastes a lot of time), so I am doing the lazy thing by asking this
question:

Can we go back to just the using the attribute cache timeout, or should we
get all heuristical about readdir?

Ben