Cache the locations of the first Write chunk and the Reply chunk so
that the Send path doesn't need to parse the Call header again.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
include/linux/sunrpc/svc_rdma.h | 2 ++
net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 24 +++++++++++++-------
net/sunrpc/xprtrdma/svc_rdma_sendto.c | 38 +++----------------------------
3 files changed, 22 insertions(+), 42 deletions(-)
diff --git a/include/linux/sunrpc/svc_rdma.h b/include/linux/sunrpc/svc_rdma.h
index 04e4a34d1c6a..07baeb5f93c1 100644
--- a/include/linux/sunrpc/svc_rdma.h
+++ b/include/linux/sunrpc/svc_rdma.h
@@ -137,6 +137,8 @@ struct svc_rdma_recv_ctxt {
unsigned int rc_page_count;
unsigned int rc_hdr_count;
u32 rc_inv_rkey;
+ __be32 *rc_write_list;
+ __be32 *rc_reply_chunk;
unsigned int rc_read_payload_offset;
unsigned int rc_read_payload_length;
struct page *rc_pages[RPCSVC_MAXPAGES];
diff --git a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
index 2f16c0625226..91abe08f7d75 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_recvfrom.c
@@ -444,15 +444,17 @@ static __be32 *xdr_check_write_chunk(__be32 *p, const __be32 *end,
* - This implementation supports only one Write chunk.
*
* Sanity checks:
- * - Write list does not overflow buffer.
+ * - Write list does not overflow Receive buffer.
* - Segment size limited by largest NFS data payload.
*
* Returns pointer to the following Reply chunk.
*/
-static __be32 *xdr_check_write_list(__be32 *p, const __be32 *end)
+static __be32 *xdr_check_write_list(__be32 *p, const __be32 *end,
+ struct svc_rdma_recv_ctxt *ctxt)
{
u32 chcount;
+ ctxt->rc_write_list = p;
chcount = 0;
while (*p++ != xdr_zero) {
p = xdr_check_write_chunk(p, end, MAX_BYTES_WRITE_SEG);
@@ -461,6 +463,8 @@ static __be32 *xdr_check_write_list(__be32 *p, const __be32 *end)
if (chcount++ > 1)
return NULL;
}
+ if (!chcount)
+ ctxt->rc_write_list = NULL;
return p;
}
@@ -472,13 +476,16 @@ static __be32 *xdr_check_write_list(__be32 *p, const __be32 *end)
*
* Returns pointer to the following RPC header.
*/
-static __be32 *xdr_check_reply_chunk(__be32 *p, const __be32 *end)
+static __be32 *xdr_check_reply_chunk(__be32 *p, const __be32 *end,
+ struct svc_rdma_recv_ctxt *ctxt)
{
+ ctxt->rc_reply_chunk = p;
if (*p++ != xdr_zero) {
p = xdr_check_write_chunk(p, end, MAX_BYTES_SPECIAL_SEG);
if (!p)
return NULL;
- }
+ } else
+ ctxt->rc_reply_chunk = NULL;
return p;
}
@@ -554,7 +561,8 @@ static void svc_rdma_get_inv_rkey(struct svcxprt_rdma *rdma,
* 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 *ctxt)
{
__be32 *p, *end, *rdma_argp;
unsigned int hdr_len;
@@ -587,10 +595,10 @@ static int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg)
p = xdr_check_read_list(rdma_argp + 4, end);
if (!p)
goto out_inval;
- p = xdr_check_write_list(p, end);
+ p = xdr_check_write_list(p, end, ctxt);
if (!p)
goto out_inval;
- p = xdr_check_reply_chunk(p, end);
+ p = xdr_check_reply_chunk(p, end, ctxt);
if (!p)
goto out_inval;
if (p > end)
@@ -792,7 +800,7 @@ 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)
diff --git a/net/sunrpc/xprtrdma/svc_rdma_sendto.c b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
index 40b4843be869..3c0e41d378bc 100644
--- a/net/sunrpc/xprtrdma/svc_rdma_sendto.c
+++ b/net/sunrpc/xprtrdma/svc_rdma_sendto.c
@@ -454,36 +454,6 @@ static void svc_rdma_xdr_encode_reply_chunk(__be32 *rdma_resp, __be32 *rp_ch,
xdr_encode_write_chunk(p, rp_ch, consumed);
}
-/* Parse the RPC Call's transport header.
- */
-static void svc_rdma_get_write_arrays(__be32 *rdma_argp,
- __be32 **write, __be32 **reply)
-{
- __be32 *p;
-
- p = rdma_argp + rpcrdma_fixed_maxsz;
-
- /* Read list */
- while (*p++ != xdr_zero)
- p += 5;
-
- /* Write list */
- if (*p != xdr_zero) {
- *write = p;
- while (*p++ != xdr_zero)
- p += 1 + be32_to_cpu(*p) * 4;
- } else {
- *write = NULL;
- p++;
- }
-
- /* Reply chunk */
- if (*p != xdr_zero)
- *reply = p;
- else
- *reply = NULL;
-}
-
static int svc_rdma_dma_map_page(struct svcxprt_rdma *rdma,
struct svc_rdma_send_ctxt *ctxt,
struct page *page,
@@ -842,14 +812,14 @@ int svc_rdma_sendto(struct svc_rqst *rqstp)
struct svcxprt_rdma *rdma =
container_of(xprt, struct svcxprt_rdma, sc_xprt);
struct svc_rdma_recv_ctxt *rctxt = rqstp->rq_xprt_ctxt;
- __be32 *p, *rdma_argp, *rdma_resp, *wr_lst, *rp_ch;
+ __be32 *rdma_argp = rctxt->rc_recv_buf;
+ __be32 *wr_lst = rctxt->rc_write_list;
+ __be32 *rp_ch = rctxt->rc_reply_chunk;
struct xdr_buf *xdr = &rqstp->rq_res;
struct svc_rdma_send_ctxt *sctxt;
+ __be32 *p, *rdma_resp;
int ret;
- rdma_argp = rctxt->rc_recv_buf;
- svc_rdma_get_write_arrays(rdma_argp, &wr_lst, &rp_ch);
-
/* Create the RDMA response header. xprt->xpt_mutex,
* acquired in svc_send(), serializes RPC replies. The
* code path below that inserts the credit grant value
