Commit 07e9a632 authored by Chuck Lever's avatar Chuck Lever
Browse files

SUNRPC: Add helpers for decoding list discriminators symbolically 



Use these helpers in a few spots to demonstrate their use.

The remaining open-coded discriminator checks in rpcrdma will be
addressed in subsequent patches.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 0b8dc1b6

include/linux/sunrpc/xdr.h

+26 −0
Original line number Diff line number Diff line
@@ -474,6 +474,32 @@ xdr_stream_encode_uint32_array(struct xdr_stream *xdr, 
	return ret;

}



/**

 * xdr_item_is_absent - symbolically handle XDR discriminators

 * @p: pointer to undecoded discriminator

 *

 * Return values:

 *   %true if the following XDR item is absent

 *   %false if the following XDR item is present

 */

static inline bool xdr_item_is_absent(const __be32 *p)

{

	return *p == xdr_zero;

}



/**

 * xdr_item_is_present - symbolically handle XDR discriminators

 * @p: pointer to undecoded discriminator

 *

 * Return values:

 *   %true if the following XDR item is present

 *   %false if the following XDR item is absent

 */

static inline bool xdr_item_is_present(const __be32 *p)

{

	return *p != xdr_zero;

}



/**

 * xdr_stream_decode_u32 - Decode a 32-bit integer

 * @xdr: pointer to xdr_stream

net/sunrpc/xprtrdma/rpc_rdma.c

+6 −6
Original line number Diff line number Diff line
@@ -1133,11 +1133,11 @@ rpcrdma_is_bcall(struct rpcrdma_xprt *r_xprt, struct rpcrdma_rep *rep) 
	p = xdr_inline_decode(xdr, 0);



	/* Chunk lists */

	if (*p++ != xdr_zero)

	if (xdr_item_is_present(p++))

		return false;

	if (*p++ != xdr_zero)

	if (xdr_item_is_present(p++))

		return false;

	if (*p++ != xdr_zero)

	if (xdr_item_is_present(p++))

		return false;



	/* RPC header */
@@ -1215,7 +1215,7 @@ static int decode_read_list(struct xdr_stream *xdr) 
	p = xdr_inline_decode(xdr, sizeof(*p));

	if (unlikely(!p))

		return -EIO;

	if (unlikely(*p != xdr_zero))

	if (unlikely(xdr_item_is_present(p)))

		return -EIO;

	return 0;

}
@@ -1234,7 +1234,7 @@ static int decode_write_list(struct xdr_stream *xdr, u32 *length) 
		p = xdr_inline_decode(xdr, sizeof(*p));

		if (unlikely(!p))

			return -EIO;

		if (*p == xdr_zero)

		if (xdr_item_is_absent(p))

			break;

		if (!first)

			return -EIO;
@@ -1256,7 +1256,7 @@ static int decode_reply_chunk(struct xdr_stream *xdr, u32 *length) 
		return -EIO;



	*length = 0;

	if (*p != xdr_zero)

	if (xdr_item_is_present(p))

		if (decode_write_chunk(xdr, length))

			return -EIO;

	return 0;

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

+8 −9
Original line number Diff line number Diff line
@@ -419,7 +419,7 @@ static bool xdr_check_read_list(struct svc_rdma_recv_ctxt *rctxt) 


	len = 0;

	first = true;

	while (*p != xdr_zero) {

	while (xdr_item_is_present(p)) {

		p = xdr_inline_decode(&rctxt->rc_stream,

				      rpcrdma_readseg_maxsz * sizeof(*p));

		if (!p)
@@ -500,7 +500,7 @@ static bool xdr_check_write_list(struct svc_rdma_recv_ctxt *rctxt) 
	if (!p)

		return false;

	rctxt->rc_write_list = p;

	while (*p != xdr_zero) {

	while (xdr_item_is_present(p)) {

		if (!xdr_check_write_chunk(rctxt, MAX_BYTES_WRITE_CHUNK))

			return false;

		++chcount;
@@ -532,12 +532,11 @@ static bool xdr_check_reply_chunk(struct svc_rdma_recv_ctxt *rctxt) 
	p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));

	if (!p)

		return false;

	rctxt->rc_reply_chunk = p;

	if (*p != xdr_zero) {

	rctxt->rc_reply_chunk = NULL;

	if (xdr_item_is_present(p)) {

		if (!xdr_check_write_chunk(rctxt, MAX_BYTES_SPECIAL_CHUNK))

			return false;

	} else {

		rctxt->rc_reply_chunk = NULL;

		rctxt->rc_reply_chunk = p;

	}

	return true;

}
@@ -568,7 +567,7 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, 
	p += rpcrdma_fixed_maxsz;



	/* Read list */

	while (*p++ != xdr_zero) {

	while (xdr_item_is_present(p++)) {

		p++;	/* position */

		if (inv_rkey == xdr_zero)

			inv_rkey = *p;
@@ -578,7 +577,7 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, 
	}



	/* Write list */

	while (*p++ != xdr_zero) {

	while (xdr_item_is_present(p++)) {

		segcount = be32_to_cpup(p++);

		for (i = 0; i < segcount; i++) {

			if (inv_rkey == xdr_zero)
@@ -590,7 +589,7 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma, 
	}



	/* Reply chunk */

	if (*p++ != xdr_zero) {

	if (xdr_item_is_present(p++)) {

		segcount = be32_to_cpup(p++);

		for (i = 0; i < segcount; i++) {

			if (inv_rkey == xdr_zero)

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