1 files changed, 176 insertions, 90 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 96bccd398469..efa5fcb5793f 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -193,6 +193,7 @@ svc_rdma_recv_ctxt_get(struct svcxprt_rdma *rdma)
 
 out:
 	ctxt->rc_page_count = 0;
+	ctxt->rc_read_payload_length = 0;
 	return ctxt;
 
 out_empty:
@@ -222,6 +223,26 @@ void svc_rdma_recv_ctxt_put(struct svcxprt_rdma *rdma,
 		svc_rdma_recv_ctxt_destroy(rdma, ctxt);
 }
 
+/**
+ * svc_rdma_release_rqst - Release transport-specific per-rqst resources
+ * @rqstp: svc_rqst being released
+ *
+ * Ensure that the recv_ctxt is released whether or not a Reply
+ * was sent. For example, the client could close the connection,
+ * or svc_process could drop an RPC, before the Reply is sent.
+ */
+void svc_rdma_release_rqst(struct svc_rqst *rqstp)
+{
+	struct svc_rdma_recv_ctxt *ctxt = rqstp->rq_xprt_ctxt;
+	struct svc_xprt *xprt = rqstp->rq_xprt;
+	struct svcxprt_rdma *rdma =
+		container_of(xprt, struct svcxprt_rdma, sc_xprt);
+
+	rqstp->rq_xprt_ctxt = NULL;
+	if (ctxt)
+		svc_rdma_recv_ctxt_put(rdma, ctxt);
+}
+
 static int __svc_rdma_post_recv(struct svcxprt_rdma *rdma,
 				struct svc_rdma_recv_ctxt *ctxt)
 {
@@ -357,15 +378,14 @@ static void svc_rdma_build_arg_xdr(struct svc_rqst *rqstp,
 	arg->len = ctxt->rc_byte_len;
 }
 
-/* This accommodates the largest possible Write chunk,
- * in one segment.
+/* This accommodates the largest possible Write chunk.
  */
-#define MAX_BYTES_WRITE_SEG	((u32)(RPCSVC_MAXPAGES << PAGE_SHIFT))
+#define MAX_BYTES_WRITE_CHUNK ((u32)(RPCSVC_MAXPAGES << PAGE_SHIFT))
 
 /* This accommodates the largest possible Position-Zero
- * Read chunk or Reply chunk, in one segment.
+ * Read chunk or Reply chunk.
  */
-#define MAX_BYTES_SPECIAL_SEG	((u32)((RPCSVC_MAXPAGES + 2) << PAGE_SHIFT))
+#define MAX_BYTES_SPECIAL_CHUNK ((u32)((RPCSVC_MAXPAGES + 2) << PAGE_SHIFT))
 
 /* Sanity check the Read list.
  *
@@ -373,7 +393,7 @@ static void svc_rdma_build_arg_xdr(struct svc_rqst *rqstp,
  * - This implementation supports only one Read chunk.
  *
  * Sanity checks:
- * - Read list does not overflow buffer.
+ * - Read list does not overflow Receive buffer.
  * - Segment size limited by largest NFS data payload.
  *
  * The segment count is limited to how many segments can
@@ -381,30 +401,44 @@ static void svc_rdma_build_arg_xdr(struct svc_rqst *rqstp,
  * buffer. That's about 40 Read segments for a 1KB inline
  * threshold.
  *
- * Returns pointer to the following Write list.
+ * Return values:
+ *       %true: Read list is valid. @rctxt's xdr_stream is updated
+ *		to point to the first byte past the Read list.
+ *      %false: Read list is corrupt. @rctxt's xdr_stream is left
+ *		in an unknown state.
  */
-static __be32 *xdr_check_read_list(__be32 *p, const __be32 *end)
+static bool xdr_check_read_list(struct svc_rdma_recv_ctxt *rctxt)
 {
-	u32 position;
+	u32 position, len;
 	bool first;
+	__be32 *p;
 
+	p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
+	if (!p)
+		return false;
+
+	len = 0;
 	first = true;
-	while (*p++ != xdr_zero) {
+	while (*p != xdr_zero) {
+		p = xdr_inline_decode(&rctxt->rc_stream,
+				      rpcrdma_readseg_maxsz * sizeof(*p));
+		if (!p)
+			return false;
+
 		if (first) {
-			position = be32_to_cpup(p++);
+			position = be32_to_cpup(p);
 			first = false;
-		} else if (be32_to_cpup(p++) != position) {
-			return NULL;
+		} else if (be32_to_cpup(p) != position) {
+			return false;
 		}
-		p++;	/* handle */
-		if (be32_to_cpup(p++) > MAX_BYTES_SPECIAL_SEG)
-			return NULL;
-		p += 2;	/* offset */
+		p += 2;
+		len += be32_to_cpup(p);
 
-		if (p > end)
-			return NULL;
+		p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
+		if (!p)
+			return false;
 	}
-	return p;
+	return len <= MAX_BYTES_SPECIAL_CHUNK;
 }
 
 /* The segment count is limited to how many segments can
@@ -412,67 +446,100 @@ static __be32 *xdr_check_read_list(__be32 *p, const __be32 *end)
  * buffer. That's about 60 Write segments for a 1KB inline
  * threshold.
  */
-static __be32 *xdr_check_write_chunk(__be32 *p, const __be32 *end,
-				     u32 maxlen)
+static bool xdr_check_write_chunk(struct svc_rdma_recv_ctxt *rctxt, u32 maxlen)
 {
-	u32 i, segcount;
+	u32 i, segcount, total;
+	__be32 *p;
 
-	segcount = be32_to_cpup(p++);
+	p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
+	if (!p)
+		return false;
+	segcount = be32_to_cpup(p);
+
+	total = 0;
 	for (i = 0; i < segcount; i++) {
-		p++;	/* handle */
-		if (be32_to_cpup(p++) > maxlen)
-			return NULL;
-		p += 2;	/* offset */
+		u32 handle, length;
+		u64 offset;
 
-		if (p > end)
-			return NULL;
-	}
+		p = xdr_inline_decode(&rctxt->rc_stream,
+				      rpcrdma_segment_maxsz * sizeof(*p));
+		if (!p)
+			return false;
+
+		handle = be32_to_cpup(p++);
+		length = be32_to_cpup(p++);
+		xdr_decode_hyper(p, &offset);
+		trace_svcrdma_decode_wseg(handle, length, offset);
 
-	return p;
+		total += length;
+	}
+	return total <= maxlen;
 }
 
 /* Sanity check the Write list.
  *
  * Implementation limits:
- * - This implementation supports only one Write chunk.
+ * - This implementation currently supports only one Write chunk.
  *
  * Sanity checks:
- * - Write list does not overflow buffer.
- * - Segment size limited by largest NFS data payload.
- *
- * Returns pointer to the following Reply chunk.
+ * - Write list does not overflow Receive buffer.
+ * - Chunk size limited by largest NFS data payload.
+ *
+ * Return values:
+ *       %true: Write list is valid. @rctxt's xdr_stream is updated
+ *		to point to the first byte past the Write list.
+ *      %false: Write list is corrupt. @rctxt's xdr_stream is left
+ *		in an unknown state.
  */
-static __be32 *xdr_check_write_list(__be32 *p, const __be32 *end)
+static bool xdr_check_write_list(struct svc_rdma_recv_ctxt *rctxt)
 {
-	u32 chcount;
+	u32 chcount = 0;
+	__be32 *p;
 
-	chcount = 0;
-	while (*p++ != xdr_zero) {
-		p = xdr_check_write_chunk(p, end, MAX_BYTES_WRITE_SEG);
+	p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
+	if (!p)
+		return false;
+	rctxt->rc_write_list = p;
+	while (*p != xdr_zero) {
+		if (!xdr_check_write_chunk(rctxt, MAX_BYTES_WRITE_CHUNK))
+			return false;
+		++chcount;
+		p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
 		if (!p)
-			return NULL;
-		if (chcount++ > 1)
-			return NULL;
+			return false;
 	}
-	return p;
+	if (!chcount)
+		rctxt->rc_write_list = NULL;
+	return chcount < 2;
 }
 
 /* Sanity check the Reply chunk.
  *
  * Sanity checks:
- * - Reply chunk does not overflow buffer.
- * - Segment size limited by largest NFS data payload.
- *
- * Returns pointer to the following RPC header.
+ * - Reply chunk does not overflow Receive buffer.
+ * - Chunk size limited by largest NFS data payload.
+ *
+ * Return values:
+ *       %true: Reply chunk is valid. @rctxt's xdr_stream is updated
+ *		to point to the first byte past the Reply chunk.
+ *      %false: Reply chunk is corrupt. @rctxt's xdr_stream is left
+ *		in an unknown state.
  */
-static __be32 *xdr_check_reply_chunk(__be32 *p, const __be32 *end)
+static bool xdr_check_reply_chunk(struct svc_rdma_recv_ctxt *rctxt)
 {
-	if (*p++ != xdr_zero) {
-		p = xdr_check_write_chunk(p, end, MAX_BYTES_SPECIAL_SEG);
-		if (!p)
-			return NULL;
+	__be32 *p;
+
+	p = xdr_inline_decode(&rctxt->rc_stream, sizeof(*p));
+	if (!p)
+		return false;
+	rctxt->rc_reply_chunk = p;
+	if (*p != xdr_zero) {
+		if (!xdr_check_write_chunk(rctxt, MAX_BYTES_SPECIAL_CHUNK))
+			return false;
+	} else {
+		rctxt->rc_reply_chunk = NULL;
 	}
-	return p;
+	return true;
 }
 
 /* RPC-over-RDMA Version One private extension: Remote Invalidation.
@@ -537,60 +604,61 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma,
 	ctxt->rc_inv_rkey = be32_to_cpu(inv_rkey);
 }
 
-/* On entry, xdr->head[0].iov_base points to first byte in the
- * RPC-over-RDMA header.
+/**
+ * svc_rdma_xdr_decode_req - Decode the transport header
+ * @rq_arg: xdr_buf containing ingress RPC/RDMA message
+ * @rctxt: state of decoding
+ *
+ * On entry, xdr->head[0].iov_base points to first byte of the
+ * RPC-over-RDMA transport header.
  *
  * On successful exit, head[0] points to first byte past the
  * RPC-over-RDMA header. For RDMA_MSG, this is the RPC message.
+ *
  * The length of the RPC-over-RDMA header is returned.
  *
  * Assumptions:
  * - The transport header is entirely contained in the head iovec.
  */
-static int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg)
+static int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg,
+				   struct svc_rdma_recv_ctxt *rctxt)
 {
-	__be32 *p, *end, *rdma_argp;
+	__be32 *p, *rdma_argp;
 	unsigned int hdr_len;
 
-	/* Verify that there's enough bytes for header + something */
-	if (rq_arg->len <= RPCRDMA_HDRLEN_ERR)
-		goto out_short;
-
 	rdma_argp = rq_arg->head[0].iov_base;
-	if (*(rdma_argp + 1) != rpcrdma_version)
-		goto out_version;
+	xdr_init_decode(&rctxt->rc_stream, rq_arg, rdma_argp, NULL);
 
-	switch (*(rdma_argp + 3)) {
+	p = xdr_inline_decode(&rctxt->rc_stream,
+			      rpcrdma_fixed_maxsz * sizeof(*p));
+	if (unlikely(!p))
+		goto out_short;
+	p++;
+	if (*p != rpcrdma_version)
+		goto out_version;
+	p += 2;
+	switch (*p) {
 	case rdma_msg:
 		break;
 	case rdma_nomsg:
 		break;
-
 	case rdma_done:
 		goto out_drop;
-
 	case rdma_error:
 		goto out_drop;
-
 	default:
 		goto out_proc;
 	}
 
-	end = (__be32 *)((unsigned long)rdma_argp + rq_arg->len);
-	p = xdr_check_read_list(rdma_argp + 4, end);
-	if (!p)
+	if (!xdr_check_read_list(rctxt))
 		goto out_inval;
-	p = xdr_check_write_list(p, end);
-	if (!p)
-		goto out_inval;
-	p = xdr_check_reply_chunk(p, end);
-	if (!p)
+	if (!xdr_check_write_list(rctxt))
 		goto out_inval;
-	if (p > end)
+	if (!xdr_check_reply_chunk(rctxt))
 		goto out_inval;
 
-	rq_arg->head[0].iov_base = p;
-	hdr_len = (unsigned long)p - (unsigned long)rdma_argp;
+	rq_arg->head[0].iov_base = rctxt->rc_stream.p;
+	hdr_len = xdr_stream_pos(&rctxt->rc_stream);
 	rq_arg->head[0].iov_len -= hdr_len;
 	rq_arg->len -= hdr_len;
 	trace_svcrdma_decode_rqst(rdma_argp, hdr_len);
@@ -650,7 +718,6 @@ static void svc_rdma_send_error(struct svcxprt_rdma *xprt,
 				__be32 *rdma_argp, int status)
 {
 	struct svc_rdma_send_ctxt *ctxt;
-	unsigned int length;
 	__be32 *p;
 	int ret;
 
@@ -658,29 +725,46 @@ static void svc_rdma_send_error(struct svcxprt_rdma *xprt,
 	if (!ctxt)
 		return;
 
-	p = ctxt->sc_xprt_buf;
+	p = xdr_reserve_space(&ctxt->sc_stream,
+			      rpcrdma_fixed_maxsz * sizeof(*p));
+	if (!p)
+		goto put_ctxt;
+
 	*p++ = *rdma_argp;
 	*p++ = *(rdma_argp + 1);
 	*p++ = xprt->sc_fc_credits;
-	*p++ = rdma_error;
+	*p = rdma_error;
+
 	switch (status) {
 	case -EPROTONOSUPPORT:
+		p = xdr_reserve_space(&ctxt->sc_stream, 3 * sizeof(*p));
+		if (!p)
+			goto put_ctxt;
+
 		*p++ = err_vers;
 		*p++ = rpcrdma_version;
-		*p++ = rpcrdma_version;
+		*p = rpcrdma_version;
 		trace_svcrdma_err_vers(*rdma_argp);
 		break;
 	default:
-		*p++ = err_chunk;
+		p = xdr_reserve_space(&ctxt->sc_stream, sizeof(*p));
+		if (!p)
+			goto put_ctxt;
+
+		*p = err_chunk;
 		trace_svcrdma_err_chunk(*rdma_argp);
 	}
-	length = (unsigned long)p - (unsigned long)ctxt->sc_xprt_buf;
-	svc_rdma_sync_reply_hdr(xprt, ctxt, length);
 
+	ctxt->sc_send_wr.num_sge = 1;
 	ctxt->sc_send_wr.opcode = IB_WR_SEND;
+	ctxt->sc_sges[0].length = ctxt->sc_hdrbuf.len;
 	ret = svc_rdma_send(xprt, &ctxt->sc_send_wr);
 	if (ret)
-		svc_rdma_send_ctxt_put(xprt, ctxt);
+		goto put_ctxt;
+	return;
+
+put_ctxt:
+	svc_rdma_send_ctxt_put(xprt, ctxt);
 }
 
 /* By convention, backchannel calls arrive via rdma_msg type
@@ -756,6 +840,8 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 	__be32 *p;
 	int ret;
 
+	rqstp->rq_xprt_ctxt = NULL;
+
 	spin_lock(&rdma_xprt->sc_rq_dto_lock);
 	ctxt = svc_rdma_next_recv_ctxt(&rdma_xprt->sc_read_complete_q);
 	if (ctxt) {
@@ -785,7 +871,7 @@ int svc_rdma_recvfrom(struct svc_rqst *rqstp)
 	rqstp->rq_next_page = rqstp->rq_respages;
 
 	p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
-	ret = svc_rdma_xdr_decode_req(&rqstp->rq_arg);
+	ret = svc_rdma_xdr_decode_req(&rqstp->rq_arg, ctxt);
 	if (ret < 0)
 		goto out_err;
 	if (ret == 0)