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-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_sendto.c105
-rw-r--r--net/sunrpc/xprtrdma/svc_rdma_transport.c9
2 files changed, 102 insertions, 12 deletions
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index cf51b8f9b15f..1f200119268c 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -537,6 +537,99 @@ void svc_rdma_sync_reply_hdr(struct svcxprt_rdma *rdma,
DMA_TO_DEVICE);
}
+/* If the xdr_buf has more elements than the device can
+ * transmit in a single RDMA Send, then the reply will
+ * have to be copied into a bounce buffer.
+ */
+static bool svc_rdma_pull_up_needed(struct svcxprt_rdma *rdma,
+ struct xdr_buf *xdr,
+ __be32 *wr_lst)
+{
+ int elements;
+
+ /* xdr->head */
+ elements = 1;
+
+ /* xdr->pages */
+ if (!wr_lst) {
+ unsigned int remaining;
+ unsigned long pageoff;
+
+ pageoff = xdr->page_base & ~PAGE_MASK;
+ remaining = xdr->page_len;
+ while (remaining) {
+ ++elements;
+ remaining -= min_t(u32, PAGE_SIZE - pageoff,
+ remaining);
+ pageoff = 0;
+ }
+ }
+
+ /* xdr->tail */
+ if (xdr->tail[0].iov_len)
+ ++elements;
+
+ /* assume 1 SGE is needed for the transport header */
+ return elements >= rdma->sc_max_send_sges;
+}
+
+/* The device is not capable of sending the reply directly.
+ * Assemble the elements of @xdr into the transport header
+ * buffer.
+ */
+static int svc_rdma_pull_up_reply_msg(struct svcxprt_rdma *rdma,
+ struct svc_rdma_send_ctxt *ctxt,
+ struct xdr_buf *xdr, __be32 *wr_lst)
+{
+ unsigned char *dst, *tailbase;
+ unsigned int taillen;
+
+ dst = ctxt->sc_xprt_buf;
+ dst += ctxt->sc_sges[0].length;
+
+ memcpy(dst, xdr->head[0].iov_base, xdr->head[0].iov_len);
+ dst += xdr->head[0].iov_len;
+
+ tailbase = xdr->tail[0].iov_base;
+ taillen = xdr->tail[0].iov_len;
+ if (wr_lst) {
+ u32 xdrpad;
+
+ xdrpad = xdr_padsize(xdr->page_len);
+ if (taillen && xdrpad) {
+ tailbase += xdrpad;
+ taillen -= xdrpad;
+ }
+ } else {
+ unsigned int len, remaining;
+ unsigned long pageoff;
+ struct page **ppages;
+
+ ppages = xdr->pages + (xdr->page_base >> PAGE_SHIFT);
+ pageoff = xdr->page_base & ~PAGE_MASK;
+ remaining = xdr->page_len;
+ while (remaining) {
+ len = min_t(u32, PAGE_SIZE - pageoff, remaining);
+
+ memcpy(dst, page_address(*ppages), len);
+ remaining -= len;
+ dst += len;
+ pageoff = 0;
+ }
+ }
+
+ if (taillen)
+ memcpy(dst, tailbase, taillen);
+
+ ctxt->sc_sges[0].length += xdr->len;
+ ib_dma_sync_single_for_device(rdma->sc_pd->device,
+ ctxt->sc_sges[0].addr,
+ ctxt->sc_sges[0].length,
+ DMA_TO_DEVICE);
+
+ return 0;
+}
+
/* svc_rdma_map_reply_msg - Map the buffer holding RPC message
* @rdma: controlling transport
* @ctxt: send_ctxt for the Send WR
@@ -559,8 +652,10 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
u32 xdr_pad;
int ret;
- if (++ctxt->sc_cur_sge_no >= rdma->sc_max_send_sges)
- return -EIO;
+ if (svc_rdma_pull_up_needed(rdma, xdr, wr_lst))
+ return svc_rdma_pull_up_reply_msg(rdma, ctxt, xdr, wr_lst);
+
+ ++ctxt->sc_cur_sge_no;
ret = svc_rdma_dma_map_buf(rdma, ctxt,
xdr->head[0].iov_base,
xdr->head[0].iov_len);
@@ -591,8 +686,7 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
while (remaining) {
len = min_t(u32, PAGE_SIZE - page_off, remaining);
- if (++ctxt->sc_cur_sge_no >= rdma->sc_max_send_sges)
- return -EIO;
+ ++ctxt->sc_cur_sge_no;
ret = svc_rdma_dma_map_page(rdma, ctxt, *ppages++,
page_off, len);
if (ret < 0)
@@ -606,8 +700,7 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma,
len = xdr->tail[0].iov_len;
tail:
if (len) {
- if (++ctxt->sc_cur_sge_no >= rdma->sc_max_send_sges)
- return -EIO;
+ ++ctxt->sc_cur_sge_no;
ret = svc_rdma_dma_map_buf(rdma, ctxt, base, len);
if (ret < 0)
return ret;
diff --git a/net/sunrpc/xprtrdma/svc_rdma_transport.c b/net/sunrpc/xprtrdma/svc_rdma_transport.c
index 924c17d46903..57f86c63a463 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_transport.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_transport.c
@@ -419,12 +419,9 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
/* Transport header, head iovec, tail iovec */
newxprt->sc_max_send_sges = 3;
/* Add one SGE per page list entry */
- newxprt->sc_max_send_sges += svcrdma_max_req_size / PAGE_SIZE;
- if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge) {
- pr_err("svcrdma: too few Send SGEs available (%d needed)\n",
- newxprt->sc_max_send_sges);
- goto errout;
- }
+ newxprt->sc_max_send_sges += (svcrdma_max_req_size / PAGE_SIZE) + 1;
+ if (newxprt->sc_max_send_sges > dev->attrs.max_send_sge)
+ newxprt->sc_max_send_sges = dev->attrs.max_send_sge;
newxprt->sc_max_req_size = svcrdma_max_req_size;
newxprt->sc_max_requests = svcrdma_max_requests;
newxprt->sc_max_bc_requests = svcrdma_max_bc_requests;