SUNRPC: Add a bvec array to struct xdr_buf for use with iovec_iter()

Add a bvec array to struct xdr_buf, and have the client allocate it
when we need to receive data into pages.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index 4318292..7455871 100644 (file)
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -18,6 +18,7 @@
 #include <asm/unaligned.h>
 #include <linux/scatterlist.h>
 
+struct bio_vec;
 struct rpc_rqst;
 
 /*
@@ -52,6 +53,7 @@ struct xdr_buf {
        struct kvec     head[1],        /* RPC header + non-page data */
                        tail[1];        /* Appended after page data */
 
+       struct bio_vec  *bvec;
        struct page **  pages;          /* Array of pages */
        unsigned int    page_base,      /* Start of page data */
                        page_len,       /* Length of page data */
@@ -70,6 +72,8 @@ xdr_buf_init(struct xdr_buf *buf, void *start, size_t len)
        buf->head[0].iov_base = start;
        buf->head[0].iov_len = len;
        buf->tail[0].iov_len = 0;
+       buf->bvec = NULL;
+       buf->pages = NULL;
        buf->page_len = 0;
        buf->flags = 0;
        buf->len = 0;
@@ -116,6 +120,9 @@ __be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
 void   xdr_inline_pages(struct xdr_buf *, unsigned int,
                         struct page **, unsigned int, unsigned int);
 void   xdr_terminate_string(struct xdr_buf *, const u32);
+size_t xdr_buf_pagecount(struct xdr_buf *buf);
+int    xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp);
+void   xdr_free_bvec(struct xdr_buf *buf);
 
 static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
 {

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 9be3990..a4ab4f8 100644 (file)
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -141,6 +141,7 @@ struct rpc_xprt_ops {
        void            (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
        int             (*buf_alloc)(struct rpc_task *task);
        void            (*buf_free)(struct rpc_task *task);
+       void            (*prepare_request)(struct rpc_rqst *req);
        int             (*send_request)(struct rpc_rqst *req);
        void            (*set_retrans_timeout)(struct rpc_task *task);
        void            (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
@@ -343,6 +344,7 @@ int                 xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
 void                   xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
 void                   xprt_free_slot(struct rpc_xprt *xprt,
                                       struct rpc_rqst *req);
+void                   xprt_request_prepare(struct rpc_rqst *req);
 bool                   xprt_prepare_transmit(struct rpc_task *task);
 void                   xprt_request_enqueue_transmit(struct rpc_task *task);
 void                   xprt_request_enqueue_receive(struct rpc_task *task);

diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 0c4b2e7..ae3b814 100644 (file)
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -1753,6 +1753,8 @@ rpc_xdr_encode(struct rpc_task *task)
 
        task->tk_status = rpcauth_wrap_req(task, encode, req, p,
                        task->tk_msg.rpc_argp);
+       if (task->tk_status == 0)
+               xprt_request_prepare(req);
 }
 
 /*
@@ -1768,7 +1770,7 @@ call_encode(struct rpc_task *task)
        /* Did the encode result in an error condition? */
        if (task->tk_status != 0) {
                /* Was the error nonfatal? */
-               if (task->tk_status == -EAGAIN)
+               if (task->tk_status == -EAGAIN || task->tk_status == -ENOMEM)
                        rpc_delay(task, HZ >> 4);
                else
                        rpc_exit(task, task->tk_status);

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index 30afbd2..2bbb8d3 100644 (file)
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -15,6 +15,7 @@
 #include <linux/errno.h>
 #include <linux/sunrpc/xdr.h>
 #include <linux/sunrpc/msg_prot.h>
+#include <linux/bvec.h>
 
 /*
  * XDR functions for basic NFS types
@@ -128,6 +129,39 @@ xdr_terminate_string(struct xdr_buf *buf, const u32 len)
 }
 EXPORT_SYMBOL_GPL(xdr_terminate_string);
 
+size_t
+xdr_buf_pagecount(struct xdr_buf *buf)
+{
+       if (!buf->page_len)
+               return 0;
+       return (buf->page_base + buf->page_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+}
+
+int
+xdr_alloc_bvec(struct xdr_buf *buf, gfp_t gfp)
+{
+       size_t i, n = xdr_buf_pagecount(buf);
+
+       if (n != 0 && buf->bvec == NULL) {
+               buf->bvec = kmalloc_array(n, sizeof(buf->bvec[0]), gfp);
+               if (!buf->bvec)
+                       return -ENOMEM;
+               for (i = 0; i < n; i++) {
+                       buf->bvec[i].bv_page = buf->pages[i];
+                       buf->bvec[i].bv_len = PAGE_SIZE;
+                       buf->bvec[i].bv_offset = 0;
+               }
+       }
+       return 0;
+}
+
+void
+xdr_free_bvec(struct xdr_buf *buf)
+{
+       kfree(buf->bvec);
+       buf->bvec = NULL;
+}
+
 void
 xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
                 struct page **pages, unsigned int base, unsigned int len)

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 7333874..7ee9f1e 100644 (file)
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -1264,6 +1264,22 @@ xprt_request_dequeue_transmit(struct rpc_task *task)
 }
 
 /**
+ * xprt_request_prepare - prepare an encoded request for transport
+ * @req: pointer to rpc_rqst
+ *
+ * Calls into the transport layer to do whatever is needed to prepare
+ * the request for transmission or receive.
+ */
+void
+xprt_request_prepare(struct rpc_rqst *req)
+{
+       struct rpc_xprt *xprt = req->rq_xprt;
+
+       if (xprt->ops->prepare_request)
+               xprt->ops->prepare_request(req);
+}
+
+/**
  * xprt_request_need_retransmit - Test if a task needs retransmission
  * @task: pointer to rpc_task
  *
@@ -1727,6 +1743,7 @@ void xprt_release(struct rpc_task *task)
        if (req->rq_buffer)
                xprt->ops->buf_free(task);
        xprt_inject_disconnect(xprt);
+       xdr_free_bvec(&req->rq_rcv_buf);
        if (req->rq_cred != NULL)
                put_rpccred(req->rq_cred);
        task->tk_rqstp = NULL;