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Date:   Wed, 2 Oct 2019 15:55:11 -0400
To:     Olga Kornievskaia <olga.kornievskaia@gmail.com>
Cc:     trond.myklebust@hammerspace.com, anna.schumaker@netapp.com,
        bfields@redhat.com, linux-nfs@vger.kernel.org
Subject: Re: [PATCH v7 18/19] NFSD: allow inter server COPY to have a STALE
 source server fh
Message-ID: <20191002195511.GA21809@fieldses.org>
References: <20190916211353.18802-1-olga.kornievskaia@gmail.com>
 <20190916211353.18802-19-olga.kornievskaia@gmail.com>
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From:   bfields@fieldses.org (J. Bruce Fields)
Sender: linux-nfs-owner@vger.kernel.org
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On Mon, Sep 16, 2019 at 05:13:52PM -0400, Olga Kornievskaia wrote:
> @@ -1956,6 +1964,45 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>  		- rqstp->rq_auth_slack;
>  }
>  
> +#ifdef CONFIG_NFSD_V4_2_INTER_SSC
> +static __be32
> +check_if_stalefh_allowed(struct nfsd4_compoundargs *args)
> +{
> +	struct nfsd4_op	*op, *current_op, *saved_op;

current_op and saved_op need to be initialized to NULL here.

> +	struct nfsd4_copy *copy;
> +	struct nfsd4_putfh *putfh;
> +	int i;
> +
> +	/* traverse all operation and if it's a COPY compound, mark the
> +	 * source filehandle to skip verification
> +	 */
> +	for (i = 0; i < args->opcnt; i++) {
> +		op = &args->ops[i];
> +		if (op->opnum == OP_PUTFH)
> +			current_op = op;
> +		else if (op->opnum == OP_SAVEFH)
> +			saved_op = current_op;
> +		else if (op->opnum == OP_RESTOREFH)
> +			current_op = saved_op;
> +		else if (op->opnum == OP_COPY) {
> +			copy = (struct nfsd4_copy *)&op->u;
> +			if (!saved_op)
> +				return nfserr_nofilehandle;

Looks like this results in returning an empty compound result with just
the bare result.  I believe what we need to do is execute all the
ops preceding the COPY normally, then return the nofilehandle error on
the COPY.

One approach might be

		if (!saved_op) {
			op->status = nfserr_nofilehandle;
			return;
		}

and change check_if_stalefh_allowed to have no return value.

--b.

> +			putfh = (struct nfsd4_putfh *)&saved_op->u;
> +			if (!copy->cp_intra)
> +				putfh->no_verify = true;
> +		}
> +	}
> +	return nfs_ok;
> +}
...
> @@ -2004,6 +2051,9 @@ static void svcxdr_init_encode(struct svc_rqst *rqstp,
>  		resp->opcnt = 1;
>  		goto encode_op;
>  	}
> +	status = check_if_stalefh_allowed(args);
> +	if (status)
> +		goto out;

>  
>  	trace_nfsd_compound(rqstp, args->opcnt);
>  	while (!status && resp->opcnt < args->opcnt) {