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Commit f820c57e authored by Tom Tucker's avatar Tom Tucker
Browse files

svcrdma: Use reply and chunk map for RDMA_READ processing 



Modify the RDMA_READ processing to use the reply and chunk list mapping data
types. Also add a special purpose 'hdr_count' field in in the context to hold
the header page count instead of overloading the SGE length field and
corrupting the DMA map length.

Signed-off-by: default avatarTom Tucker <tom@opengridcomputing.com>
parent 34d16e42

include/linux/sunrpc/svc_rdma.h

+1 −0
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ extern atomic_t rdma_stat_sq_prod; 
 */

struct svc_rdma_op_ctxt {

	struct svc_rdma_op_ctxt *read_hdr;

	int hdr_count;

	struct list_head free_list;

	struct xdr_buf arg;

	struct list_head dto_q;

net/sunrpc/xprtrdma/svc_rdma_recvfrom.c

+38 −45
Original line number Diff line number Diff line
@@ -112,11 +112,6 @@ static void rdma_build_arg_xdr(struct svc_rqst *rqstp, 
	rqstp->rq_arg.tail[0].iov_len = 0;

}



struct chunk_sge {

	int start;		/* sge no for this chunk */

	int count;		/* sge count for this chunk */

};



/* Encode a read-chunk-list as an array of IB SGE

 *

 * Assumptions:
@@ -134,8 +129,8 @@ static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, 
			   struct svc_rqst *rqstp,

			   struct svc_rdma_op_ctxt *head,

			   struct rpcrdma_msg *rmsgp,

			   struct ib_sge *sge,

			   struct chunk_sge *ch_sge_ary,

			   struct svc_rdma_req_map *rpl_map,

			   struct svc_rdma_req_map *chl_map,

			   int ch_count,

			   int byte_count)

{
@@ -156,22 +151,18 @@ static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, 
	head->arg.head[0] = rqstp->rq_arg.head[0];

	head->arg.tail[0] = rqstp->rq_arg.tail[0];

	head->arg.pages = &head->pages[head->count];

	head->sge[0].length = head->count; /* save count of hdr pages */

	head->hdr_count = head->count; /* save count of hdr pages */

	head->arg.page_base = 0;

	head->arg.page_len = ch_bytes;

	head->arg.len = rqstp->rq_arg.len + ch_bytes;

	head->arg.buflen = rqstp->rq_arg.buflen + ch_bytes;

	head->count++;

	ch_sge_ary[0].start = 0;

	chl_map->ch[0].start = 0;

	while (byte_count) {

		rpl_map->sge[sge_no].iov_base =

			page_address(rqstp->rq_arg.pages[page_no]) + page_off;

		sge_bytes = min_t(int, PAGE_SIZE-page_off, ch_bytes);

		sge[sge_no].addr =

			ib_dma_map_page(xprt->sc_cm_id->device,

					rqstp->rq_arg.pages[page_no],

					page_off, sge_bytes,

					DMA_FROM_DEVICE);

		sge[sge_no].length = sge_bytes;

		sge[sge_no].lkey = xprt->sc_phys_mr->lkey;

		rpl_map->sge[sge_no].iov_len = sge_bytes;

		/*

		 * Don't bump head->count here because the same page

		 * may be used by multiple SGE.
@@ -187,11 +178,11 @@ static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, 
		 * SGE, move to the next SGE

		 */

		if (ch_bytes == 0) {

			ch_sge_ary[ch_no].count =

				sge_no - ch_sge_ary[ch_no].start;

			chl_map->ch[ch_no].count =

				sge_no - chl_map->ch[ch_no].start;

			ch_no++;

			ch++;

			ch_sge_ary[ch_no].start = sge_no;

			chl_map->ch[ch_no].start = sge_no;

			ch_bytes = ch->rc_target.rs_length;

			/* If bytes remaining account for next chunk */

			if (byte_count) {
@@ -220,18 +211,24 @@ static int rdma_rcl_to_sge(struct svcxprt_rdma *xprt, 
	return sge_no;

}



static void rdma_set_ctxt_sge(struct svc_rdma_op_ctxt *ctxt,

			      struct ib_sge *sge,

static void rdma_set_ctxt_sge(struct svcxprt_rdma *xprt,

			      struct svc_rdma_op_ctxt *ctxt,

			      struct kvec *vec,

			      u64 *sgl_offset,

			      int count)

{

	int i;



	ctxt->count = count;

	ctxt->direction = DMA_FROM_DEVICE;

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

		ctxt->sge[i].addr = sge[i].addr;

		ctxt->sge[i].length = sge[i].length;

		*sgl_offset = *sgl_offset + sge[i].length;

		ctxt->sge[i].addr =

			ib_dma_map_single(xprt->sc_cm_id->device,

					  vec[i].iov_base, vec[i].iov_len,

					  DMA_FROM_DEVICE);

		ctxt->sge[i].length = vec[i].iov_len;

		ctxt->sge[i].lkey = xprt->sc_phys_mr->lkey;

		*sgl_offset = *sgl_offset + vec[i].iov_len;

	}

}
@@ -282,34 +279,29 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, 
	struct ib_send_wr read_wr;

	int err = 0;

	int ch_no;

	struct ib_sge *sge;

	int ch_count;

	int byte_count;

	int sge_count;

	u64 sgl_offset;

	struct rpcrdma_read_chunk *ch;

	struct svc_rdma_op_ctxt *ctxt = NULL;

	struct svc_rdma_op_ctxt *tmp_sge_ctxt;

	struct svc_rdma_op_ctxt *tmp_ch_ctxt;

	struct chunk_sge *ch_sge_ary;

	struct svc_rdma_req_map *rpl_map;

	struct svc_rdma_req_map *chl_map;



	/* If no read list is present, return 0 */

	ch = svc_rdma_get_read_chunk(rmsgp);

	if (!ch)

		return 0;



	/* Allocate temporary contexts to keep SGE */

	BUG_ON(sizeof(struct ib_sge) < sizeof(struct chunk_sge));

	tmp_sge_ctxt = svc_rdma_get_context(xprt);

	sge = tmp_sge_ctxt->sge;

	tmp_ch_ctxt = svc_rdma_get_context(xprt);

	ch_sge_ary = (struct chunk_sge *)tmp_ch_ctxt->sge;

	/* Allocate temporary reply and chunk maps */

	rpl_map = svc_rdma_get_req_map();

	chl_map = svc_rdma_get_req_map();



	svc_rdma_rcl_chunk_counts(ch, &ch_count, &byte_count);

	if (ch_count > RPCSVC_MAXPAGES)

		return -EINVAL;

	sge_count = rdma_rcl_to_sge(xprt, rqstp, hdr_ctxt, rmsgp,

				    sge, ch_sge_ary,

				    rpl_map, chl_map,

				    ch_count, byte_count);

	sgl_offset = 0;

	ch_no = 0;
@@ -331,14 +323,15 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, 
		read_wr.wr.rdma.remote_addr =

			get_unaligned(&(ch->rc_target.rs_offset)) +

			sgl_offset;

		read_wr.sg_list = &sge[ch_sge_ary[ch_no].start];

		read_wr.sg_list = ctxt->sge;

		read_wr.num_sge =

			rdma_read_max_sge(xprt, ch_sge_ary[ch_no].count);

		rdma_set_ctxt_sge(ctxt, &sge[ch_sge_ary[ch_no].start],

			rdma_read_max_sge(xprt, chl_map->ch[ch_no].count);

		rdma_set_ctxt_sge(xprt, ctxt,

				  &rpl_map->sge[chl_map->ch[ch_no].start],

				  &sgl_offset,

				  read_wr.num_sge);

		if (((ch+1)->rc_discrim == 0) &&

		    (read_wr.num_sge == ch_sge_ary[ch_no].count)) {

		    (read_wr.num_sge == chl_map->ch[ch_no].count)) {

			/*

			 * Mark the last RDMA_READ with a bit to

			 * indicate all RPC data has been fetched from
@@ -358,9 +351,9 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, 
		}

		atomic_inc(&rdma_stat_read);



		if (read_wr.num_sge < ch_sge_ary[ch_no].count) {

			ch_sge_ary[ch_no].count -= read_wr.num_sge;

			ch_sge_ary[ch_no].start += read_wr.num_sge;

		if (read_wr.num_sge < chl_map->ch[ch_no].count) {

			chl_map->ch[ch_no].count -= read_wr.num_sge;

			chl_map->ch[ch_no].start += read_wr.num_sge;

			goto next_sge;

		}

		sgl_offset = 0;
@@ -368,8 +361,8 @@ static int rdma_read_xdr(struct svcxprt_rdma *xprt, 
	}



 out:

	svc_rdma_put_context(tmp_sge_ctxt, 0);

	svc_rdma_put_context(tmp_ch_ctxt, 0);

	svc_rdma_put_req_map(rpl_map);

	svc_rdma_put_req_map(chl_map);



	/* Detach arg pages. svc_recv will replenish them */

	for (ch_no = 0; &rqstp->rq_pages[ch_no] < rqstp->rq_respages; ch_no++)
@@ -399,7 +392,7 @@ static int rdma_read_complete(struct svc_rqst *rqstp, 
		rqstp->rq_pages[page_no] = head->pages[page_no];

	}

	/* Point rq_arg.pages past header */

	rqstp->rq_arg.pages = &rqstp->rq_pages[head->sge[0].length];

	rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];

	rqstp->rq_arg.page_len = head->arg.page_len;

	rqstp->rq_arg.page_base = head->arg.page_base;