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From:   Malahal Naineni <malahal@gmail.com>
Date:   Fri, 2 Nov 2018 10:56:39 +0530
Message-ID: <CAGD+tkyTyOb-iiykQLYMoa1h5cmizbe_0M0_HS=9cQC1NDznSw@mail.gmail.com>
Subject: "(deleted)" directories
To:     linux-nfs@vger.kernel.org
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Sender: linux-nfs-owner@vger.kernel.org
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Hi All, we are using NFS-Ganesha with Linux NFS clients. The client's
shell reports the following. Based on lsof, the directory is marked
deleted. "cd to ROOT and cd to the same home directory fixes the
issue. The client behaves as though the directory is deleted and
recreated! Our NFS-Ganesha server implementation uses multiple file
handles that point to the same object. NFS spec says this should be
fine, but Linux NFS seems to be broken in this regard. tcpdump does
indicate file handle change (note that all file handles are permanent,
meaning they are valid at the server any time) around this issue time.

"shell-init: error retrieving current directory: getcwd: cannot access
parent directories: No such file or directory"
sh        112544            malahal  cwd       DIR               0,67
     65536   45605209 /home/malahal (deleted)
(10.120.154.42:/nfs/malahal-export/)

Function nfs_prime_dcache() seems to invalidate the dcache entry if
nfs_same_file() returns false. nfs_same_file() does seem to return
false with the following change, if I read it correctly, if there is a
file handle change. Can this be the source of my issue? It seems that
the client should do this only if the file handle is NOT valid (e.g.
if it gets ESTALE), right?

The following commit seems to assume that the objects are different if
they have different file handles!
commit 7dc72d5f7a0ec97a53e126c46e2cbd2560757955
Author: Trond Myklebust <trond.myklebust@primarydata.com>
Date:   Thu Sep 22 13:38:52 2016 -0400

    NFS: Fix inode corruption in nfs_prime_dcache()