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From:   "Benjamin Coddington" <bcodding@redhat.com>
To:     trondmy@kernel.org
Cc:     "Xiyu Yang" <xiyuyang19@fudan.edu.cn>, linux-nfs@vger.kernel.org
Subject: Re: [PATCH] SUNRPC: Convert rpc_client refcount to use refcount_t
Date:   Mon, 19 Jul 2021 08:01:25 -0400
Message-ID: <6AF75462-495E-4B63-9A3E-C9639C45C1F2@redhat.com>
In-Reply-To: <20210717172052.232420-1-trondmy@kernel.org>
References: <20210717172052.232420-1-trondmy@kernel.org>
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Hi Trond,

On 17 Jul 2021, at 13:20, trondmy@kernel.org wrote:

> @@ -943,7 +941,7 @@ rpc_release_client(struct rpc_clnt *clnt)
>  	do {
>  		if (list_empty(&clnt->cl_tasks))
>  			wake_up(&destroy_wait);
> -		if (!atomic_dec_and_test(&clnt->cl_count))
> +		if (refcount_dec_not_one(&clnt->cl_count))

I guess we're not worried about extra calls racing into rpc_free_auth?

.. hmm, it looks like current code can do that already since we're bumping the
ref up again.  Seems like we could end up in rpcauth_release twice with
an underflow on au_count.

Ben