Commit c7848f69 authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: OPEN must handle the NFS4ERR_IO return code correctly 



decode_op_hdr() cannot distinguish between an XDR decoding error and
the perfectly valid errorcode NFS4ERR_IO. This is normally not a
problem, but for the particular case of OPEN, we need to be able
to increment the NFSv4 open sequence id when the server returns
a valid response.

Reported-by: default avatarJ Bruce Fields <bfields@fieldses.org>
Link: http://lkml.kernel.org/r/20131204210356.GA19452@fieldses.org


Signed-off-by: default avatarTrond Myklebust <trond.myklebust@primarydata.com>
Cc: stable@vger.kernel.org
parent 374b1057

fs/nfs/nfs4xdr.c

+31 −16
Original line number Diff line number Diff line
@@ -3097,7 +3097,8 @@ out_overflow: 
	return -EIO;

}



static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)

static bool __decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected,

		int *nfs_retval)

{

	__be32 *p;

	uint32_t opnum;
@@ -3107,19 +3108,32 @@ static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected) 
	if (unlikely(!p))

		goto out_overflow;

	opnum = be32_to_cpup(p++);

	if (opnum != expected) {

	if (unlikely(opnum != expected))

		goto out_bad_operation;

	nfserr = be32_to_cpup(p);

	if (nfserr == NFS_OK)

		*nfs_retval = 0;

	else

		*nfs_retval = nfs4_stat_to_errno(nfserr);

	return true;

out_bad_operation:

	dprintk("nfs: Server returned operation"

		" %d but we issued a request for %d\n",

			opnum, expected);

		return -EIO;

	}

	nfserr = be32_to_cpup(p);

	if (nfserr != NFS_OK)

		return nfs4_stat_to_errno(nfserr);

	return 0;

	*nfs_retval = -EREMOTEIO;

	return false;

out_overflow:

	print_overflow_msg(__func__, xdr);

	return -EIO;

	*nfs_retval = -EIO;

	return false;

}



static int decode_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)

{

	int retval;



	__decode_op_hdr(xdr, expected, &retval);

	return retval;

}



/* Dummy routine */
@@ -5001,10 +5015,11 @@ static int decode_open(struct xdr_stream *xdr, struct nfs_openres *res) 
	uint32_t savewords, bmlen, i;

	int status;



	status = decode_op_hdr(xdr, OP_OPEN);

	if (status != -EIO)

	if (!__decode_op_hdr(xdr, OP_OPEN, &status))

		return status;

	nfs_increment_open_seqid(status, res->seqid);

	if (!status)

	if (status)

		return status;

	status = decode_stateid(xdr, &res->stateid);

	if (unlikely(status))

		return status;

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