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>
This commit is contained in:
Trond Myklebust 2018-09-13 12:22:04 -04:00
parent 431f6eb357
commit 9d96acbc7f
5 changed files with 63 additions and 1 deletions

View File

@ -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)
{

View File

@ -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);

View File

@ -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);

View File

@ -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)

View File

@ -1263,6 +1263,22 @@ xprt_request_dequeue_transmit(struct rpc_task *task)
spin_unlock(&xprt->queue_lock);
}
/**
* 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;