4 files changed, 78 insertions, 104 deletions

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index f2eda15..8a6bdbd 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -541,9 +541,9 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 	req->rl_send_iov[0].length = hdrlen;
 	req->rl_send_iov[0].lkey = req->rl_iov.lkey;
 
-	req->rl_send_iov[1].addr = req->rl_iov.addr + (base - req->rl_base);
+	req->rl_send_iov[1].addr = rdmab_addr(req->rl_sendbuf);
 	req->rl_send_iov[1].length = rpclen;
-	req->rl_send_iov[1].lkey = req->rl_iov.lkey;
+	req->rl_send_iov[1].lkey = rdmab_lkey(req->rl_sendbuf);
 
 	req->rl_niovs = 2;
 
@@ -556,7 +556,7 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 
 		req->rl_send_iov[3].addr = req->rl_send_iov[1].addr + rpclen;
 		req->rl_send_iov[3].length = rqst->rq_slen - rpclen;
-		req->rl_send_iov[3].lkey = req->rl_iov.lkey;
+		req->rl_send_iov[3].lkey = rdmab_lkey(req->rl_sendbuf);
 
 		req->rl_niovs = 4;
 	}
diff --git a/net/sunrpc/xprtrdma/transport.c b/net/sunrpc/xprtrdma/transport.c
index 808b3c5..a9d5662 100644
--- a/net/sunrpc/xprtrdma/transport.c
+++ b/net/sunrpc/xprtrdma/transport.c
@@ -449,77 +449,72 @@ xprt_rdma_connect(struct rpc_xprt *xprt, struct rpc_task *task)
 /*
  * The RDMA allocate/free functions need the task structure as a place
  * to hide the struct rpcrdma_req, which is necessary for the actual send/recv
- * sequence. For this reason, the recv buffers are attached to send
- * buffers for portions of the RPC. Note that the RPC layer allocates
- * both send and receive buffers in the same call. We may register
- * the receive buffer portion when using reply chunks.
+ * sequence.
+ *
+ * The RPC layer allocates both send and receive buffers in the same call
+ * (rq_send_buf and rq_rcv_buf are both part of a single contiguous buffer).
+ * We may register rq_rcv_buf when using reply chunks.
  */
 static void *
 xprt_rdma_allocate(struct rpc_task *task, size_t size)
 {
 	struct rpc_xprt *xprt = task->tk_rqstp->rq_xprt;
-	struct rpcrdma_req *req, *nreq;
+	struct rpcrdma_xprt *r_xprt = rpcx_to_rdmax(xprt);
+	struct rpcrdma_regbuf *rb;
+	struct rpcrdma_req *req;
+	size_t min_size;
+	gfp_t flags = task->tk_flags & RPC_TASK_SWAPPER ?
+						GFP_ATOMIC : GFP_NOFS;
 
-	req = rpcrdma_buffer_get(&rpcx_to_rdmax(xprt)->rx_buf);
+	req = rpcrdma_buffer_get(&r_xprt->rx_buf);
 	if (req == NULL)
 		return NULL;
 
-	if (size > req->rl_size) {
-		dprintk("RPC:       %s: size %zd too large for buffer[%zd]: "
-			"prog %d vers %d proc %d\n",
-			__func__, size, req->rl_size,
-			task->tk_client->cl_prog, task->tk_client->cl_vers,
-			task->tk_msg.rpc_proc->p_proc);
-		/*
-		 * Outgoing length shortage. Our inline write max must have
-		 * been configured to perform direct i/o.
-		 *
-		 * This is therefore a large metadata operation, and the
-		 * allocate call was made on the maximum possible message,
-		 * e.g. containing long filename(s) or symlink data. In
-		 * fact, while these metadata operations *might* carry
-		 * large outgoing payloads, they rarely *do*. However, we
-		 * have to commit to the request here, so reallocate and
-		 * register it now. The data path will never require this
-		 * reallocation.
-		 *
-		 * If the allocation or registration fails, the RPC framework
-		 * will (doggedly) retry.
-		 */
-		if (task->tk_flags & RPC_TASK_SWAPPER)
-			nreq = kmalloc(sizeof *req + size, GFP_ATOMIC);
-		else
-			nreq = kmalloc(sizeof *req + size, GFP_NOFS);
-		if (nreq == NULL)
-			goto outfail;
-
-		if (rpcrdma_register_internal(&rpcx_to_rdmax(xprt)->rx_ia,
-				nreq->rl_base, size + sizeof(struct rpcrdma_req)
-				- offsetof(struct rpcrdma_req, rl_base),
-				&nreq->rl_handle, &nreq->rl_iov)) {
-			kfree(nreq);
-			goto outfail;
-		}
-		rpcx_to_rdmax(xprt)->rx_stats.hardway_register_count += size;
-		nreq->rl_size = size;
-		nreq->rl_niovs = 0;
-		nreq->rl_nchunks = 0;
-		nreq->rl_buffer = (struct rpcrdma_buffer *)req;
-		nreq->rl_reply = req->rl_reply;
-		memcpy(nreq->rl_segments,
-			req->rl_segments, sizeof nreq->rl_segments);
-		/* flag the swap with an unused field */
-		nreq->rl_iov.length = 0;
-		req->rl_reply = NULL;
-		req = nreq;
-	}
+	if (req->rl_sendbuf == NULL)
+		goto out_sendbuf;
+	if (size > req->rl_sendbuf->rg_size)
+		goto out_sendbuf;
+
+out:
 	dprintk("RPC:       %s: size %zd, request 0x%p\n", __func__, size, req);
 	req->rl_connect_cookie = 0;	/* our reserved value */
-	return req->rl_xdr_buf;
-
-outfail:
+	return req->rl_sendbuf->rg_base;
+
+out_sendbuf:
+	/* XDR encoding and RPC/RDMA marshaling of this request has not
+	 * yet occurred. Thus a lower bound is needed to prevent buffer
+	 * overrun during marshaling.
+	 *
+	 * RPC/RDMA marshaling may choose to send payload bearing ops
+	 * inline, if the result is smaller than the inline threshold.
+	 * The value of the "size" argument accounts for header
+	 * requirements but not for the payload in these cases.
+	 *
+	 * Likewise, allocate enough space to receive a reply up to the
+	 * size of the inline threshold.
+	 *
+	 * It's unlikely that both the send header and the received
+	 * reply will be large, but slush is provided here to allow
+	 * flexibility when marshaling.
+	 */
+	min_size = RPCRDMA_INLINE_READ_THRESHOLD(task->tk_rqstp);
+	min_size += RPCRDMA_INLINE_WRITE_THRESHOLD(task->tk_rqstp);
+	if (size < min_size)
+		size = min_size;
+
+	rb = rpcrdma_alloc_regbuf(&r_xprt->rx_ia, size, flags);
+	if (IS_ERR(rb))
+		goto out_fail;
+	rb->rg_owner = req;
+
+	r_xprt->rx_stats.hardway_register_count += size;
+	rpcrdma_free_regbuf(&r_xprt->rx_ia, req->rl_sendbuf);
+	req->rl_sendbuf = rb;
+	goto out;
+
+out_fail:
 	rpcrdma_buffer_put(req);
-	rpcx_to_rdmax(xprt)->rx_stats.failed_marshal_count++;
+	r_xprt->rx_stats.failed_marshal_count++;
 	return NULL;
 }
 
@@ -531,47 +526,24 @@ xprt_rdma_free(void *buffer)
 {
 	struct rpcrdma_req *req;
 	struct rpcrdma_xprt *r_xprt;
-	struct rpcrdma_rep *rep;
+	struct rpcrdma_regbuf *rb;
 	int i;
 
 	if (buffer == NULL)
 		return;
 
-	req = container_of(buffer, struct rpcrdma_req, rl_xdr_buf[0]);
-	if (req->rl_iov.length == 0) {	/* see allocate above */
-		r_xprt = container_of(((struct rpcrdma_req *) req->rl_buffer)->rl_buffer,
-				      struct rpcrdma_xprt, rx_buf);
-	} else
-		r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
-	rep = req->rl_reply;
+	rb = container_of(buffer, struct rpcrdma_regbuf, rg_base[0]);
+	req = rb->rg_owner;
+	r_xprt = container_of(req->rl_buffer, struct rpcrdma_xprt, rx_buf);
 
-	dprintk("RPC:       %s: called on 0x%p%s\n",
-		__func__, rep, (rep && rep->rr_func) ? " (with waiter)" : "");
+	dprintk("RPC:       %s: called on 0x%p\n", __func__, req->rl_reply);
 
-	/*
-	 * Finish the deregistration.  The process is considered
-	 * complete when the rr_func vector becomes NULL - this
-	 * was put in place during rpcrdma_reply_handler() - the wait
-	 * call below will not block if the dereg is "done". If
-	 * interrupted, our framework will clean up.
-	 */
 	for (i = 0; req->rl_nchunks;) {
 		--req->rl_nchunks;
 		i += rpcrdma_deregister_external(
 			&req->rl_segments[i], r_xprt);
 	}
 
-	if (req->rl_iov.length == 0) {	/* see allocate above */
-		struct rpcrdma_req *oreq = (struct rpcrdma_req *)req->rl_buffer;
-		oreq->rl_reply = req->rl_reply;
-		(void) rpcrdma_deregister_internal(&r_xprt->rx_ia,
-						   req->rl_handle,
-						   &req->rl_iov);
-		kfree(req);
-		req = oreq;
-	}
-
-	/* Put back request+reply buffers */
 	rpcrdma_buffer_put(req);
 }
 
diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index cdd6aac..4089440 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -1079,25 +1079,22 @@ static struct rpcrdma_req *
 rpcrdma_create_req(struct rpcrdma_xprt *r_xprt)
 {
 	struct rpcrdma_create_data_internal *cdata = &r_xprt->rx_data;
-	size_t wlen = 1 << fls(cdata->inline_wsize +
-			       sizeof(struct rpcrdma_req));
+	size_t wlen = cdata->inline_wsize;
 	struct rpcrdma_ia *ia = &r_xprt->rx_ia;
 	struct rpcrdma_req *req;
 	int rc;
 
 	rc = -ENOMEM;
-	req = kmalloc(wlen, GFP_KERNEL);
+	req = kmalloc(sizeof(*req) + wlen, GFP_KERNEL);
 	if (req == NULL)
 		goto out;
-	memset(req, 0, sizeof(struct rpcrdma_req));
+	memset(req, 0, sizeof(*req));
 
-	rc = rpcrdma_register_internal(ia, req->rl_base, wlen -
-				       offsetof(struct rpcrdma_req, rl_base),
+	rc = rpcrdma_register_internal(ia, req->rl_base, wlen,
 				       &req->rl_handle, &req->rl_iov);
 	if (rc)
 		goto out_free;
 
-	req->rl_size = wlen - sizeof(struct rpcrdma_req);
 	req->rl_buffer = &r_xprt->rx_buf;
 	return req;
 
@@ -1121,7 +1118,7 @@ rpcrdma_create_rep(struct rpcrdma_xprt *r_xprt)
 	rep = kmalloc(rlen, GFP_KERNEL);
 	if (rep == NULL)
 		goto out;
-	memset(rep, 0, sizeof(struct rpcrdma_rep));
+	memset(rep, 0, sizeof(*rep));
 
 	rc = rpcrdma_register_internal(ia, rep->rr_base, rlen -
 				       offsetof(struct rpcrdma_rep, rr_base),
@@ -1335,6 +1332,7 @@ rpcrdma_destroy_req(struct rpcrdma_ia *ia, struct rpcrdma_req *req)
 	if (!req)
 		return;
 
+	rpcrdma_free_regbuf(ia, req->rl_sendbuf);
 	rpcrdma_deregister_internal(ia, req->rl_handle, &req->rl_iov);
 	kfree(req);
 }
@@ -1729,8 +1727,6 @@ rpcrdma_recv_buffer_get(struct rpcrdma_req *req)
 	struct rpcrdma_buffer *buffers = req->rl_buffer;
 	unsigned long flags;
 
-	if (req->rl_iov.length == 0)	/* special case xprt_rdma_allocate() */
-		buffers = ((struct rpcrdma_req *) buffers)->rl_buffer;
 	spin_lock_irqsave(&buffers->rb_lock, flags);
 	if (buffers->rb_recv_index < buffers->rb_max_requests) {
 		req->rl_reply = buffers->rb_recv_bufs[buffers->rb_recv_index];
diff --git a/net/sunrpc/xprtrdma/xprt_rdma.h b/net/sunrpc/xprtrdma/xprt_rdma.h
index 36c37c6..aa82f8d 100644
--- a/net/sunrpc/xprtrdma/xprt_rdma.h
+++ b/net/sunrpc/xprtrdma/xprt_rdma.h
@@ -262,7 +262,6 @@ struct rpcrdma_mr_seg {		/* chunk descriptors */
 };
 
 struct rpcrdma_req {
-	size_t 		rl_size;	/* actual length of buffer */
 	unsigned int	rl_niovs;	/* 0, 2 or 4 */
 	unsigned int	rl_nchunks;	/* non-zero if chunks */
 	unsigned int	rl_connect_cookie;	/* retry detection */
@@ -271,13 +270,20 @@ struct rpcrdma_req {
 	struct rpcrdma_rep	*rl_reply;/* holder for reply buffer */
 	struct rpcrdma_mr_seg rl_segments[RPCRDMA_MAX_SEGS];/* chunk segments */
 	struct ib_sge	rl_send_iov[4];	/* for active requests */
+	struct rpcrdma_regbuf *rl_sendbuf;
 	struct ib_sge	rl_iov;		/* for posting */
 	struct ib_mr	*rl_handle;	/* handle for mem in rl_iov */
 	char		rl_base[MAX_RPCRDMAHDR]; /* start of actual buffer */
-	__u32 		rl_xdr_buf[0];	/* start of returned rpc rq_buffer */
 };
-#define rpcr_to_rdmar(r) \
-	container_of((r)->rq_buffer, struct rpcrdma_req, rl_xdr_buf[0])
+
+static inline struct rpcrdma_req *
+rpcr_to_rdmar(struct rpc_rqst *rqst)
+{
+	struct rpcrdma_regbuf *rb = container_of(rqst->rq_buffer,
+						 struct rpcrdma_regbuf,
+						 rg_base[0]);
+	return rb->rg_owner;
+}
 
 /*
  * struct rpcrdma_buffer -- holds list/queue of pre-registered memory for