Commit 4554755e authored by Chuck Lever's avatar Chuck Lever
Browse files

svcrdma: Update synopsis of svc_rdma_map_reply_msg() 



Preparing for subsequent patches, no behavior change expected.

Pass the RPC Call's svc_rdma_recv_ctxt deeper into the sendto()
path. This enables passing more information about Requester-
provided Write and Reply chunks into those lower-level functions.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 6fa5785e

include/linux/sunrpc/svc_rdma.h

+3 −2
Original line number Diff line number Diff line
@@ -193,8 +193,9 @@ extern void svc_rdma_sync_reply_hdr(struct svcxprt_rdma *rdma, 
				    struct svc_rdma_send_ctxt *ctxt,

				    unsigned int len);

extern int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,

				  struct svc_rdma_send_ctxt *ctxt,

				  struct xdr_buf *xdr, __be32 *wr_lst);

				  struct svc_rdma_send_ctxt *sctxt,

				  const struct svc_rdma_recv_ctxt *rctxt,

				  struct xdr_buf *xdr);

extern int svc_rdma_sendto(struct svc_rqst *);

extern int svc_rdma_read_payload(struct svc_rqst *rqstp, unsigned int offset,

				 unsigned int length);

net/sunrpc/xprtrdma/svc_rdma_backchannel.c

+1 −1
Original line number Diff line number Diff line
@@ -117,7 +117,7 @@ static int svc_rdma_bc_sendto(struct svcxprt_rdma *rdma, 
{

	int ret;



	ret = svc_rdma_map_reply_msg(rdma, ctxt, &rqst->rq_snd_buf, NULL);

	ret = svc_rdma_map_reply_msg(rdma, ctxt, NULL, &rqst->rq_snd_buf);

	if (ret < 0)

		return -EIO;

net/sunrpc/xprtrdma/svc_rdma_sendto.c

+49 −33
Original line number Diff line number Diff line
@@ -502,13 +502,19 @@ void svc_rdma_sync_reply_hdr(struct svcxprt_rdma *rdma, 
				      DMA_TO_DEVICE);

}



/* If the xdr_buf has more elements than the device can

 * transmit in a single RDMA Send, then the reply will

 * have to be copied into a bounce buffer.

/**

 * svc_rdma_pull_up_needed - Determine whether to use pull-up

 * @rdma: controlling transport

 * @rctxt: Write and Reply chunks provided by client

 * @xdr: xdr_buf containing RPC message to transmit

 *

 * Returns:

 *	%true if pull-up must be used

 *	%false otherwise

 */

static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma,

				    struct xdr_buf *xdr,

				    __be32 *wr_lst)

				    const struct svc_rdma_recv_ctxt *rctxt,

				    struct xdr_buf *xdr)

{

	int elements;
@@ -516,7 +522,7 @@ static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma, 
	elements = 1;



	/* xdr->pages */

	if (!wr_lst) {

	if (!rctxt || !rctxt->rc_write_list) {

		unsigned int remaining;

		unsigned long pageoff;
@@ -538,26 +544,35 @@ static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma, 
	return elements >= rdma->sc_max_send_sges;

}



/* The device is not capable of sending the reply directly.

 * Assemble the elements of @xdr into the transport header

 * buffer.

/**

 * svc_rdma_pull_up_reply_msg - Copy Reply into a single buffer

 * @rdma: controlling transport

 * @sctxt: send_ctxt for the Send WR; xprt hdr is already prepared

 * @rctxt: Write and Reply chunks provided by client

 * @xdr: prepared xdr_buf containing RPC message

 *

 * The device is not capable of sending the reply directly.

 * Assemble the elements of @xdr into the transport header buffer.

 *

 * Returns zero on success, or a negative errno on failure.

 */

static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma,

				      struct svc_rdma_send_ctxt *ctxt,

				      struct xdr_buf *xdr, __be32 *wr_lst)

				      struct svc_rdma_send_ctxt *sctxt,

				      const struct svc_rdma_recv_ctxt *rctxt,

				      const struct xdr_buf *xdr)

{

	unsigned char *dst, *tailbase;

	unsigned int taillen;



	dst = ctxt->sc_xprt_buf;

	dst += ctxt->sc_sges[0].length;

	dst = sctxt->sc_xprt_buf;

	dst += sctxt->sc_sges[0].length;



	memcpy(dst, xdr->head[0].iov_base, xdr->head[0].iov_len);

	dst += xdr->head[0].iov_len;



	tailbase = xdr->tail[0].iov_base;

	taillen = xdr->tail[0].iov_len;

	if (wr_lst) {

	if (rctxt && rctxt->rc_write_list) {

		u32 xdrpad;



		xdrpad = xdr_pad_size(xdr->page_len);
@@ -586,20 +601,20 @@ static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma, 
	if (taillen)

		memcpy(dst, tailbase, taillen);



	ctxt->sc_sges[0].length += xdr->len;

	sctxt->sc_sges[0].length += xdr->len;

	ib_dma_sync_single_for_device(rdma->sc_pd->device,

				      ctxt->sc_sges[0].addr,

				      ctxt->sc_sges[0].length,

				      sctxt->sc_sges[0].addr,

				      sctxt->sc_sges[0].length,

				      DMA_TO_DEVICE);



	return 0;

}



/* svc_rdma_map_reply_msg - Map the buffer holding RPC message

/* svc_rdma_map_reply_msg - DMA map the buffer holding RPC message

 * @rdma: controlling transport

 * @ctxt: send_ctxt for the Send WR

 * @sctxt: send_ctxt for the Send WR

 * @rctxt: Write and Reply chunks provided by client

 * @xdr: prepared xdr_buf containing RPC message

 * @wr_lst: pointer to Call header's Write list, or NULL

 *

 * Load the xdr_buf into the ctxt's sge array, and DMA map each

 * element as it is added.
@@ -607,8 +622,9 @@ static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma, 
 * Returns zero on success, or a negative errno on failure.

 */

int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,

			   struct svc_rdma_send_ctxt *ctxt,

			   struct xdr_buf *xdr, __be32 *wr_lst)

			   struct svc_rdma_send_ctxt *sctxt,

			   const struct svc_rdma_recv_ctxt *rctxt,

			   struct xdr_buf *xdr)

{

	unsigned int len, remaining;

	unsigned long page_off;
@@ -617,11 +633,11 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 
	u32 xdr_pad;

	int ret;



	if (svc_rdma_pull_up_needed(rdma, xdr, wr_lst))

		return svc_rdma_pull_up_reply_msg(rdma, ctxt, xdr, wr_lst);

	if (svc_rdma_pull_up_needed(rdma, rctxt, xdr))

		return svc_rdma_pull_up_reply_msg(rdma, sctxt, rctxt, xdr);



	++ctxt->sc_cur_sge_no;

	ret = svc_rdma_dma_map_buf(rdma, ctxt,

	++sctxt->sc_cur_sge_no;

	ret = svc_rdma_dma_map_buf(rdma, sctxt,

				   xdr->head[0].iov_base,

				   xdr->head[0].iov_len);

	if (ret < 0)
@@ -632,7 +648,7 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 
	 * have added XDR padding in the tail buffer, and that

	 * should not be included inline.

	 */

	if (wr_lst) {

	if (rctxt && rctxt->rc_write_list) {

		base = xdr->tail[0].iov_base;

		len = xdr->tail[0].iov_len;

		xdr_pad = xdr_pad_size(xdr->page_len);
@@ -651,8 +667,8 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 
	while (remaining) {

		len = min_t(u32, PAGE_SIZE - page_off, remaining);



		++ctxt->sc_cur_sge_no;

		ret = svc_rdma_dma_map_page(rdma, ctxt, *ppages++,

		++sctxt->sc_cur_sge_no;

		ret = svc_rdma_dma_map_page(rdma, sctxt, *ppages++,

					    page_off, len);

		if (ret < 0)

			return ret;
@@ -665,8 +681,8 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 
	len = xdr->tail[0].iov_len;

tail:

	if (len) {

		++ctxt->sc_cur_sge_no;

		ret = svc_rdma_dma_map_buf(rdma, ctxt, base, len);

		++sctxt->sc_cur_sge_no;

		ret = svc_rdma_dma_map_buf(rdma, sctxt, base, len);

		if (ret < 0)

			return ret;

	}
@@ -720,8 +736,8 @@ static int svc_rdma_send_reply_msg(struct svcxprt_rdma *rdma, 
	int ret;



	if (!rp_ch) {

		ret = svc_rdma_map_reply_msg(rdma, sctxt,

					     &rqstp->rq_res, wr_lst);

		ret = svc_rdma_map_reply_msg(rdma, sctxt, rctxt,

					     &rqstp->rq_res);

		if (ret < 0)

			return ret;

	}

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