1 files changed, 81 insertions, 44 deletions

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 694e9b13ecf0..ca4d6e4528f3 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -141,7 +141,7 @@ static bool rpcrdma_args_inline(struct rpcrdma_xprt *r_xprt,
 
 	if (xdr->page_len) {
 		remaining = xdr->page_len;
-		offset = xdr->page_base & ~PAGE_MASK;
+		offset = offset_in_page(xdr->page_base);
 		count = 0;
 		while (remaining) {
 			remaining -= min_t(unsigned int,
@@ -222,7 +222,7 @@ rpcrdma_convert_iovs(struct rpcrdma_xprt *r_xprt, struct xdr_buf *xdrbuf,
 
 	len = xdrbuf->page_len;
 	ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
-	page_base = xdrbuf->page_base & ~PAGE_MASK;
+	page_base = offset_in_page(xdrbuf->page_base);
 	p = 0;
 	while (len && n < RPCRDMA_MAX_SEGS) {
 		if (!ppages[p]) {
@@ -540,7 +540,7 @@ rpcrdma_prepare_msg_sges(struct rpcrdma_ia *ia, struct rpcrdma_req *req,
 			goto out;
 
 		page = virt_to_page(xdr->tail[0].iov_base);
-		page_base = (unsigned long)xdr->tail[0].iov_base & ~PAGE_MASK;
+		page_base = offset_in_page(xdr->tail[0].iov_base);
 
 		/* If the content in the page list is an odd length,
 		 * xdr_write_pages() has added a pad at the beginning
@@ -557,7 +557,7 @@ rpcrdma_prepare_msg_sges(struct rpcrdma_ia *ia, struct rpcrdma_req *req,
 	 */
 	if (xdr->page_len) {
 		ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
-		page_base = xdr->page_base & ~PAGE_MASK;
+		page_base = offset_in_page(xdr->page_base);
 		remaining = xdr->page_len;
 		while (remaining) {
 			sge_no++;
@@ -587,7 +587,7 @@ rpcrdma_prepare_msg_sges(struct rpcrdma_ia *ia, struct rpcrdma_req *req,
 	 */
 	if (xdr->tail[0].iov_len) {
 		page = virt_to_page(xdr->tail[0].iov_base);
-		page_base = (unsigned long)xdr->tail[0].iov_base & ~PAGE_MASK;
+		page_base = offset_in_page(xdr->tail[0].iov_base);
 		len = xdr->tail[0].iov_len;
 
 map_tail:
@@ -734,6 +734,9 @@ rpcrdma_marshal_req(struct rpc_rqst *rqst)
 		rpclen = 0;
 	}
 
+	req->rl_xid = rqst->rq_xid;
+	rpcrdma_insert_req(&r_xprt->rx_buf, req);
+
 	/* This implementation supports the following combinations
 	 * of chunk lists in one RPC-over-RDMA Call message:
 	 *
@@ -875,9 +878,9 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
 	srcp += curlen;
 	copy_len -= curlen;
 
-	page_base = rqst->rq_rcv_buf.page_base;
-	ppages = rqst->rq_rcv_buf.pages + (page_base >> PAGE_SHIFT);
-	page_base &= ~PAGE_MASK;
+	ppages = rqst->rq_rcv_buf.pages +
+		(rqst->rq_rcv_buf.page_base >> PAGE_SHIFT);
+	page_base = offset_in_page(rqst->rq_rcv_buf.page_base);
 	fixup_copy_count = 0;
 	if (copy_len && rqst->rq_rcv_buf.page_len) {
 		int pagelist_len;
@@ -928,6 +931,24 @@ rpcrdma_inline_fixup(struct rpc_rqst *rqst, char *srcp, int copy_len, int pad)
 	return fixup_copy_count;
 }
 
+/* Caller must guarantee @rep remains stable during this call.
+ */
+static void
+rpcrdma_mark_remote_invalidation(struct list_head *mws,
+				 struct rpcrdma_rep *rep)
+{
+	struct rpcrdma_mw *mw;
+
+	if (!(rep->rr_wc_flags & IB_WC_WITH_INVALIDATE))
+		return;
+
+	list_for_each_entry(mw, mws, mw_list)
+		if (mw->mw_handle == rep->rr_inv_rkey) {
+			mw->mw_flags = RPCRDMA_MW_F_RI;
+			break; /* only one invalidated MR per RPC */
+		}
+}
+
 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
 /* By convention, backchannel calls arrive via rdma_msg type
  * messages, and never populate the chunk lists. This makes
@@ -969,14 +990,16 @@ rpcrdma_reply_handler(struct work_struct *work)
 {
 	struct rpcrdma_rep *rep =
 			container_of(work, struct rpcrdma_rep, rr_work);
+	struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
+	struct rpcrdma_buffer *buf = &r_xprt->rx_buf;
+	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 	struct rpcrdma_msg *headerp;
 	struct rpcrdma_req *req;
 	struct rpc_rqst *rqst;
-	struct rpcrdma_xprt *r_xprt = rep->rr_rxprt;
-	struct rpc_xprt *xprt = &r_xprt->rx_xprt;
 	__be32 *iptr;
 	int rdmalen, status, rmerr;
 	unsigned long cwnd;
+	struct list_head mws;
 
 	dprintk("RPC:       %s: incoming rep %p\n", __func__, rep);
 
@@ -994,27 +1017,45 @@ rpcrdma_reply_handler(struct work_struct *work)
 	/* Match incoming rpcrdma_rep to an rpcrdma_req to
 	 * get context for handling any incoming chunks.
 	 */
-	spin_lock_bh(&xprt->transport_lock);
-	rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
-	if (!rqst)
+	spin_lock(&buf->rb_lock);
+	req = rpcrdma_lookup_req_locked(&r_xprt->rx_buf,
+					headerp->rm_xid);
+	if (!req)
 		goto out_nomatch;
-
-	req = rpcr_to_rdmar(rqst);
 	if (req->rl_reply)
 		goto out_duplicate;
 
-	/* Sanity checking has passed. We are now committed
-	 * to complete this transaction.
+	list_replace_init(&req->rl_registered, &mws);
+	rpcrdma_mark_remote_invalidation(&mws, rep);
+
+	/* Avoid races with signals and duplicate replies
+	 * by marking this req as matched.
 	 */
-	list_del_init(&rqst->rq_list);
-	spin_unlock_bh(&xprt->transport_lock);
+	req->rl_reply = rep;
+	spin_unlock(&buf->rb_lock);
+
 	dprintk("RPC:       %s: reply %p completes request %p (xid 0x%08x)\n",
 		__func__, rep, req, be32_to_cpu(headerp->rm_xid));
 
-	/* from here on, the reply is no longer an orphan */
-	req->rl_reply = rep;
-	xprt->reestablish_timeout = 0;
+	/* Invalidate and unmap the data payloads before waking the
+	 * waiting application. This guarantees the memory regions
+	 * are properly fenced from the server before the application
+	 * accesses the data. It also ensures proper send flow control:
+	 * waking the next RPC waits until this RPC has relinquished
+	 * all its Send Queue entries.
+	 */
+	if (!list_empty(&mws))
+		r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, &mws);
 
+	/* Perform XID lookup, reconstruction of the RPC reply, and
+	 * RPC completion while holding the transport lock to ensure
+	 * the rep, rqst, and rq_task pointers remain stable.
+	 */
+	spin_lock_bh(&xprt->transport_lock);
+	rqst = xprt_lookup_rqst(xprt, headerp->rm_xid);
+	if (!rqst)
+		goto out_norqst;
+	xprt->reestablish_timeout = 0;
 	if (headerp->rm_vers != rpcrdma_version)
 		goto out_badversion;
 
@@ -1024,12 +1065,9 @@ rpcrdma_reply_handler(struct work_struct *work)
 	case rdma_msg:
 		/* never expect read chunks */
 		/* never expect reply chunks (two ways to check) */
-		/* never expect write chunks without having offered RDMA */
 		if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
 		    (headerp->rm_body.rm_chunks[1] == xdr_zero &&
-		     headerp->rm_body.rm_chunks[2] != xdr_zero) ||
-		    (headerp->rm_body.rm_chunks[1] != xdr_zero &&
-		     list_empty(&req->rl_registered)))
+		     headerp->rm_body.rm_chunks[2] != xdr_zero))
 			goto badheader;
 		if (headerp->rm_body.rm_chunks[1] != xdr_zero) {
 			/* count any expected write chunks in read reply */
@@ -1066,8 +1104,7 @@ rpcrdma_reply_handler(struct work_struct *work)
 		/* never expect read or write chunks, always reply chunks */
 		if (headerp->rm_body.rm_chunks[0] != xdr_zero ||
 		    headerp->rm_body.rm_chunks[1] != xdr_zero ||
-		    headerp->rm_body.rm_chunks[2] != xdr_one ||
-		    list_empty(&req->rl_registered))
+		    headerp->rm_body.rm_chunks[2] != xdr_one)
 			goto badheader;
 		iptr = (__be32 *)((unsigned char *)headerp +
 							RPCRDMA_HDRLEN_MIN);
@@ -1093,17 +1130,6 @@ badheader:
 	}
 
 out:
-	/* Invalidate and flush the data payloads before waking the
-	 * waiting application. This guarantees the memory region is
-	 * properly fenced from the server before the application
-	 * accesses the data. It also ensures proper send flow
-	 * control: waking the next RPC waits until this RPC has
-	 * relinquished all its Send Queue entries.
-	 */
-	if (!list_empty(&req->rl_registered))
-		r_xprt->rx_ia.ri_ops->ro_unmap_sync(r_xprt, req);
-
-	spin_lock_bh(&xprt->transport_lock);
 	cwnd = xprt->cwnd;
 	xprt->cwnd = atomic_read(&r_xprt->rx_buf.rb_credits) << RPC_CWNDSHIFT;
 	if (xprt->cwnd > cwnd)
@@ -1112,7 +1138,7 @@ out:
 	xprt_complete_rqst(rqst->rq_task, status);
 	spin_unlock_bh(&xprt->transport_lock);
 	dprintk("RPC:       %s: xprt_complete_rqst(0x%p, 0x%p, %d)\n",
-			__func__, xprt, rqst, status);
+		__func__, xprt, rqst, status);
 	return;
 
 out_badstatus:
@@ -1161,26 +1187,37 @@ out_rdmaerr:
 	r_xprt->rx_stats.bad_reply_count++;
 	goto out;
 
-/* If no pending RPC transaction was matched, post a replacement
- * receive buffer before returning.
+/* The req was still available, but by the time the transport_lock
+ * was acquired, the rqst and task had been released. Thus the RPC
+ * has already been terminated.
  */
+out_norqst:
+	spin_unlock_bh(&xprt->transport_lock);
+	rpcrdma_buffer_put(req);
+	dprintk("RPC:       %s: race, no rqst left for req %p\n",
+		__func__, req);
+	return;
+
 out_shortreply:
 	dprintk("RPC:       %s: short/invalid reply\n", __func__);
 	goto repost;
 
 out_nomatch:
-	spin_unlock_bh(&xprt->transport_lock);
+	spin_unlock(&buf->rb_lock);
 	dprintk("RPC:       %s: no match for incoming xid 0x%08x len %d\n",
 		__func__, be32_to_cpu(headerp->rm_xid),
 		rep->rr_len);
 	goto repost;
 
 out_duplicate:
-	spin_unlock_bh(&xprt->transport_lock);
+	spin_unlock(&buf->rb_lock);
 	dprintk("RPC:       %s: "
 		"duplicate reply %p to RPC request %p: xid 0x%08x\n",
 		__func__, rep, req, be32_to_cpu(headerp->rm_xid));
 
+/* If no pending RPC transaction was matched, post a replacement
+ * receive buffer before returning.
+ */
 repost:
 	r_xprt->rx_stats.bad_reply_count++;
 	if (rpcrdma_ep_post_recv(&r_xprt->rx_ia, rep))