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From:   Olga Kornievskaia <olga.kornievskaia@gmail.com>
Date:   Wed, 22 Jan 2020 15:27:40 -0500
Message-ID: <CAN-5tyH1KXWGRfgmAibVJ0kFpHX3FZpGDdhYBFVS7EBAXLu99w@mail.gmail.com>
Subject: Re: [PATCH 1/1] NFSv4.2 re-initialize cn_resp in case of a retry
To:     "Schumaker, Anna" <Anna.Schumaker@netapp.com>
Cc:     "trond.myklebust@hammerspace.com" <trond.myklebust@hammerspace.com>,
        "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
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On Wed, Jan 22, 2020 at 1:40 PM Schumaker, Anna
<Anna.Schumaker@netapp.com> wrote:
>
> Hi Olga,
>
> On Tue, 2020-01-21 at 17:14 -0500, Olga Kornievskaia wrote:
> > From: Olga Kornievskaia <kolga@netapp.com>
> >
> > If nfs42_proc_copy returned a EAGAIN, we need to re-initialize the
> > memory in case memory allocation fails.
>
> I guess I'm not sure how we would hit this. Doesn't kzalloc() return NULL if the
> memory allocation fails?

You are right kzalloc would always return NULL so forget about this patch.

>
> >
> > Fixes: 66588abe2 ("NFSv4.2 fix kfree in __nfs42_copy_file_range")
> > Reported-by: kbuild test robot <lkp@intel.com>
> > Reported-by: Julia Lawall <julia.lawall@lip6.fr>
> > Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
> > ---
> >  fs/nfs/nfs4file.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
> > index 620de90..9f72efe 100644
> > --- a/fs/nfs/nfs4file.c
> > +++ b/fs/nfs/nfs4file.c
> > @@ -177,8 +177,10 @@ static ssize_t __nfs4_copy_file_range(struct file
> > *file_in, loff_t pos_in,
> >       ret = nfs42_proc_copy(file_in, pos_in, file_out, pos_out, count,
> >                               nss, cnrs, sync);
> >  out:
> > -     if (!nfs42_files_from_same_server(file_in, file_out))
> > +     if (!nfs42_files_from_same_server(file_in, file_out)) {
> >               kfree(cn_resp);
> > +             cn_resp = NULL;
> > +     }
> >       if (ret == -EAGAIN)
> >               goto retry;
> >       return ret;