Merge branch 'for-bfields' of git://linux-nfs.org/~tomtucker/xprt-switch-2.6 into for-2.6.27

1 files changed, 70 insertions, 116 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index c22d6b6f2db..b4b17f44cb2 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -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 +211,25 @@ 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;
+		atomic_inc(&xprt->sc_dma_used);
+		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;
 	}
 }
 
@@ -260,11 +258,16 @@ static int rdma_read_max_sge(struct svcxprt_rdma *xprt, int sge_count)
  * On our side, we need to read into a pagelist. The first page immediately
  * follows the RPC header.
  *
- * This function returns 1 to indicate success. The data is not yet in
+ * This function returns:
+ * 0 - No error and no read-list found.
+ *
+ * 1 - Successful read-list processing. The data is not yet in
  * the pagelist and therefore the RPC request must be deferred. The
  * I/O completion will enqueue the transport again and
  * svc_rdma_recvfrom will complete the request.
  *
+ * <0 - Error processing/posting read-list.
+ *
  * NOTE: The ctxt must not be touched after the last WR has been posted
  * because the I/O completion processing may occur on another
  * processor and free / modify the context. Ne touche pas!
@@ -277,50 +280,38 @@ 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 *head;
-	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);
-	head = svc_rdma_get_context(xprt);
 	sgl_offset = 0;
 	ch_no = 0;
 
 	for (ch = (struct rpcrdma_read_chunk *)&rmsgp->rm_body.rm_chunks[0];
 	     ch->rc_discrim != 0; ch++, ch_no++) {
 next_sge:
-		if (!ctxt)
-			ctxt = head;
-		else {
-			ctxt->next = svc_rdma_get_context(xprt);
-			ctxt = ctxt->next;
-		}
-		ctxt->next = NULL;
+		ctxt = svc_rdma_get_context(xprt);
 		ctxt->direction = DMA_FROM_DEVICE;
-		clear_bit(RDMACTXT_F_READ_DONE, &ctxt->flags);
 		clear_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
 
 		/* Prepare READ WR */
@@ -333,50 +324,46 @@ next_sge:
 		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
 			 * the client and the RPC needs to be enqueued.
 			 */
 			set_bit(RDMACTXT_F_LAST_CTXT, &ctxt->flags);
-			ctxt->next = hdr_ctxt;
-			hdr_ctxt->next = head;
+			ctxt->read_hdr = hdr_ctxt;
 		}
 		/* Post the read */
 		err = svc_rdma_send(xprt, &read_wr);
 		if (err) {
-			printk(KERN_ERR "svcrdma: Error posting send = %d\n",
+			printk(KERN_ERR "svcrdma: Error %d posting RDMA_READ\n",
 			       err);
-			/*
-			 * Break the circular list so free knows when
-			 * to stop if the error happened to occur on
-			 * the last read
-			 */
-			ctxt->next = NULL;
+			set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
+			svc_rdma_put_context(ctxt, 0);
 			goto out;
 		}
 		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;
-		err = 0;
+		err = 1;
 	}
 
  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++)
@@ -389,25 +376,12 @@ next_sge:
 	while (rqstp->rq_resused)
 		rqstp->rq_respages[--rqstp->rq_resused] = NULL;
 
-	if (err) {
-		printk(KERN_ERR "svcrdma : RDMA_READ error = %d\n", err);
-		set_bit(XPT_CLOSE, &xprt->sc_xprt.xpt_flags);
-		/* Free the linked list of read contexts */
-		while (head != NULL) {
-			ctxt = head->next;
-			svc_rdma_put_context(head, 1);
-			head = ctxt;
-		}
-		return 0;
-	}
-
-	return 1;
+	return err;
 }
 
 static int rdma_read_complete(struct svc_rqst *rqstp,
-			      struct svc_rdma_op_ctxt *data)
+			      struct svc_rdma_op_ctxt *head)
 {
-	struct svc_rdma_op_ctxt *head = data->next;
 	int page_no;
 	int ret;
 
@@ -419,7 +393,7 @@ 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;
 
@@ -433,21 +407,12 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
 	rqstp->rq_arg.len = head->arg.len;
 	rqstp->rq_arg.buflen = head->arg.buflen;
 
+	/* Free the context */
+	svc_rdma_put_context(head, 0);
+
 	/* XXX: What should this be? */
 	rqstp->rq_prot = IPPROTO_MAX;
-
-	/*
-	 * Free the contexts we used to build the RDMA_READ. We have
-	 * to be careful here because the context list uses the same
-	 * next pointer used to chain the contexts associated with the
-	 * RDMA_READ
-	 */
-	data->next = NULL;	/* terminate circular list */
-	do {
-		data = head->next;
-		svc_rdma_put_context(head, 0);
-		head = data;
-	} while (head != NULL);
+	svc_xprt_copy_addrs(rqstp, rqstp->rq_xprt);
 
 	ret = rqstp->rq_arg.head[0].iov_len
 		+ rqstp->rq_arg.page_len
@@ -457,8 +422,6 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
 		ret, rqstp->rq_arg.len,	rqstp->rq_arg.head[0].iov_base,
 		rqstp->rq_arg.head[0].iov_len);
 
-	/* Indicate that we've consumed an RQ credit */
-	rqstp->rq_xprt_ctxt = rqstp->rq_xprt;
 	svc_xprt_received(rqstp->rq_xprt);
 	return ret;
 }
@@ -480,13 +443,6 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 
 	dprintk("svcrdma: rqstp=%p\n", rqstp);
 
-	/*
-	 * The rq_xprt_ctxt indicates if we've consumed an RQ credit
-	 * or not. It is used in the rdma xpo_release_rqst function to
-	 * determine whether or not to return an RQ WQE to the RQ.
-	 */
-	rqstp->rq_xprt_ctxt = NULL;
-
 	spin_lock_bh(&rdma_xprt->sc_read_complete_lock);
 	if (!list_empty(&rdma_xprt->sc_read_complete_q)) {
 		ctxt = list_entry(rdma_xprt->sc_read_complete_q.next,
@@ -537,21 +493,22 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 	/* If the request is invalid, reply with an error */
 	if (len < 0) {
 		if (len == -ENOSYS)
-			(void)svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
+			svc_rdma_send_error(rdma_xprt, rmsgp, ERR_VERS);
 		goto close_out;
 	}
 
-	/* Read read-list data. If we would need to wait, defer
-	 * it. Not that in this case, we don't return the RQ credit
-	 * until after the read completes.
-	 */
-	if (rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt)) {
+	/* Read read-list data. */
+	ret = rdma_read_xdr(rdma_xprt, rmsgp, rqstp, ctxt);
+	if (ret > 0) {
+		/* read-list posted, defer until data received from client. */
 		svc_xprt_received(xprt);
 		return 0;
 	}
-
-	/* Indicate we've consumed an RQ credit */
-	rqstp->rq_xprt_ctxt = rqstp->rq_xprt;
+	if (ret < 0) {
+		/* Post of read-list failed, free context. */
+		svc_rdma_put_context(ctxt, 1);
+		return 0;
+	}
 
 	ret = rqstp->rq_arg.head[0].iov_len
 		+ rqstp->rq_arg.page_len
@@ -569,11 +526,8 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 	return ret;
 
  close_out:
-	if (ctxt) {
+	if (ctxt)
 		svc_rdma_put_context(ctxt, 1);
-		/* Indicate we've consumed an RQ credit */
-		rqstp->rq_xprt_ctxt = rqstp->rq_xprt;
-	}
 	dprintk("svcrdma: transport %p is closing\n", xprt);
 	/*
 	 * Set the close bit and enqueue it. svc_recv will see the