@@ -43,6 +43,7 @@
#include <linux/sunrpc/debug.h>
#include <linux/sunrpc/rpc_rdma.h>
#include <linux/spinlock.h>
+#include <linux/highmem.h>
#include <asm/unaligned.h>
#include <rdma/ib_verbs.h>
#include <rdma/rdma_cm.h>
@@ -435,6 +436,32 @@ static int rdma_read_chunks(struct svcxprt_rdma *xprt,
return ret;
}
+/*
+ * To avoid a separate RDMA READ just for a handful of zero bytes,
+ * RFC 5666 section 3.7 allows the client to omit the XDR zero pad
+ * in chunk lists.
+ */
+static void
+rdma_fix_xdr_pad(struct xdr_buf *buf)
+{
+ unsigned int page_len = buf->page_len;
+ unsigned int size = (XDR_QUADLEN(page_len) << 2) - page_len;
+ unsigned int offset, pg_no;
+ char *p;
+
+ if (size == 0)
+ return;
+
+ pg_no = page_len >> PAGE_SHIFT;
+ offset = page_len & ~PAGE_MASK;
+ p = page_address(buf->pages[pg_no]);
+ memset(p + offset, 0, size);
+
+ buf->page_len += size;
+ buf->buflen += size;
+ buf->len += size;
+}
+
static int rdma_read_complete(struct svc_rqst *rqstp,
struct svc_rdma_op_ctxt *head)
{
@@ -449,6 +476,7 @@ static int rdma_read_complete(struct svc_rqst *rqstp,
rqstp->rq_pages[page_no] = head->pages[page_no];
}
/* Point rq_arg.pages past header */
+ rdma_fix_xdr_pad(&head->arg);
rqstp->rq_arg.pages = &rqstp->rq_pages[head->hdr_count];
rqstp->rq_arg.page_len = head->arg.page_len;
rqstp->rq_arg.page_base = head->arg.page_base;
See RFC 5666 section 3.7: clients don't have to send zero XDR padding. BugLink: https://bugzilla.linux-nfs.org/show_bug.cgi?id=246 Signed-off-by: Chuck Lever <chuck.lever@oracle.com> --- net/sunrpc/xprtrdma/svc_rdma_recvfrom.c | 28 ++++++++++++++++++++++++++++ 1 files changed, 28 insertions(+), 0 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html