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Date:   Sun, 18 Jul 2021 13:47:08 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     Trond Myklebust <trondmy@hammerspace.com>
Cc:     "tanxin.ctf@gmail.com" <tanxin.ctf@gmail.com>,
        "xiyuyang19@fudan.edu.cn" <xiyuyang19@fudan.edu.cn>,
        "davem@davemloft.net" <davem@davemloft.net>,
        "chuck.lever@oracle.com" <chuck.lever@oracle.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "kolga@netapp.com" <kolga@netapp.com>,
        "kuba@kernel.org" <kuba@kernel.org>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "bfields@fieldses.org" <bfields@fieldses.org>,
        "anna.schumaker@netapp.com" <anna.schumaker@netapp.com>,
        "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>,
        "yuanxzhang@fudan.edu.cn" <yuanxzhang@fudan.edu.cn>
Subject: Re: [PATCH] SUNRPC: Convert from atomic_t to refcount_t on
 rpc_clnt->cl_count
Message-ID: <YPQGrMEuZ2q4JhgW@unreal>
References: <1626517112-42831-1-git-send-email-xiyuyang19@fudan.edu.cn>
 <1f12b3569565fa8590b45cc2fbe7c176ca7c5184.camel@hammerspace.com>
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On Sat, Jul 17, 2021 at 02:43:26PM +0000, Trond Myklebust wrote:
> On Sat, 2021-07-17 at 18:18 +0800, Xiyu Yang wrote:
> > refcount_t type and corresponding API can protect refcounters from
> > accidental underflow and overflow and further use-after-free
> > situations.
> > 
> 
> Have you tested this patch? As far as I remember, the reason why we
> never converted is that refcount_inc() gets upset and WARNs when you
> bump a zero refcount, like we do very much on purpose in
> rpc_free_auth(). Is that no longer the case?

It is still the case, they sent gazillion conversion patches with same
mistake.

Thanks

> 
> 
> -- 
> Trond Myklebust
> Linux NFS client maintainer, Hammerspace
> trond.myklebust@hammerspace.com
> 
>