svcrdma: dma unmap the correct length for the RPCRDMA header page.

The svcrdma module was incorrectly unmapping the RPCRDMA header page.
On IBM pserver systems this causes a resource leak that results in
running out of bus address space (10 cthon iterations will reproduce it).
The code was mapping the full page but only unmapping the actual header
length.  The fix is to only map the header length.

I also cleaned up the use of ib_dma_map_page() calls since the unmap
logic always uses ib_dma_unmap_single().  I made these symmetrical.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 8b510c5e877752e876795c326f8f6381b44c770f..f11be72a1a80a1f8cc1876d23c5cce7cb5bc9ea6 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -128,7 +128,8 @@ static int fast_reg_xdr(struct svcxprt_rdma *xprt,
                page_bytes -= sge_bytes;
 
                frmr->page_list->page_list[page_no] =
-                       ib_dma_map_page(xprt->sc_cm_id->device, page, 0,
+                       ib_dma_map_single(xprt->sc_cm_id->device,
+                                         page_address(page),
                                          PAGE_SIZE, DMA_TO_DEVICE);
                if (ib_dma_mapping_error(xprt->sc_cm_id->device,
                                         frmr->page_list->page_list[page_no]))
@@ -532,18 +533,17 @@ static int send_reply(struct svcxprt_rdma *rdma,
                clear_bit(RDMACTXT_F_FAST_UNREG, &ctxt->flags);
 
        /* Prepare the SGE for the RPCRDMA Header */
+       ctxt->sge[0].lkey = rdma->sc_dma_lkey;
+       ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
        ctxt->sge[0].addr =
-               ib_dma_map_page(rdma->sc_cm_id->device,
-                               page, 0, PAGE_SIZE, DMA_TO_DEVICE);
+               ib_dma_map_single(rdma->sc_cm_id->device, page_address(page),
+                                 ctxt->sge[0].length, DMA_TO_DEVICE);
        if (ib_dma_mapping_error(rdma->sc_cm_id->device, ctxt->sge[0].addr))
                goto err;
        atomic_inc(&rdma->sc_dma_used);
 
        ctxt->direction = DMA_TO_DEVICE;
 
-       ctxt->sge[0].length = svc_rdma_xdr_get_reply_hdr_len(rdma_resp);
-       ctxt->sge[0].lkey = rdma->sc_dma_lkey;
-
        /* Determine how many of our SGE are to be transmitted */
        for (sge_no = 1; byte_count && sge_no < vec->count; sge_no++) {
                sge_bytes = min_t(size_t, vec->sge[sge_no].iov_len, byte_count);

diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 4b0c2fa15e0b6cd0526fdfd72a831cd9e42879bd..5151f9f6c5731b168dc22ac63657fd84fed8866c 100644 (file)
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -500,8 +500,8 @@ int svc_rdma_post_recv(struct svcxprt_rdma *xprt)
                BUG_ON(sge_no >= xprt->sc_max_sge);
                page = svc_rdma_get_page();
                ctxt->pages[sge_no] = page;
-               pa = ib_dma_map_page(xprt->sc_cm_id->device,
-                                    page, 0, PAGE_SIZE,
+               pa = ib_dma_map_single(xprt->sc_cm_id->device,
+                                    page_address(page), PAGE_SIZE,
                                     DMA_FROM_DEVICE);
                if (ib_dma_mapping_error(xprt->sc_cm_id->device, pa))
                        goto err_put_ctxt;
@@ -1315,8 +1315,8 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
        length = svc_rdma_xdr_encode_error(xprt, rmsgp, err, va);
 
        /* Prepare SGE for local address */
-       sge.addr = ib_dma_map_page(xprt->sc_cm_id->device,
-                                  p, 0, PAGE_SIZE, DMA_FROM_DEVICE);
+       sge.addr = ib_dma_map_single(xprt->sc_cm_id->device,
+                                  page_address(p), PAGE_SIZE, DMA_FROM_DEVICE);
        if (ib_dma_mapping_error(xprt->sc_cm_id->device, sge.addr)) {
                put_page(p);
                return;
@@ -1343,7 +1343,7 @@ void svc_rdma_send_error(struct svcxprt_rdma *xprt, struct rpcrdma_msg *rmsgp,
        if (ret) {
                dprintk("svcrdma: Error %d posting send for protocol error\n",
                        ret);
-               ib_dma_unmap_page(xprt->sc_cm_id->device,
+               ib_dma_unmap_single(xprt->sc_cm_id->device,
                                  sge.addr, PAGE_SIZE,
                                  DMA_FROM_DEVICE);
                svc_rdma_put_context(ctxt, 1);