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Diffstat (limited to 'net/sunrpc/xdr.c')
-rw-r--r--net/sunrpc/xdr.c139
1 files changed, 76 insertions, 63 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index fddcccfcdf76..0afba1b4b656 100644
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -129,34 +129,6 @@ xdr_terminate_string(struct xdr_buf *buf, const u32 len)
EXPORT_SYMBOL_GPL(xdr_terminate_string);
void
-xdr_encode_pages(struct xdr_buf *xdr, struct page **pages, unsigned int base,
- unsigned int len)
-{
- struct kvec *tail = xdr->tail;
- u32 *p;
-
- xdr->pages = pages;
- xdr->page_base = base;
- xdr->page_len = len;
-
- p = (u32 *)xdr->head[0].iov_base + XDR_QUADLEN(xdr->head[0].iov_len);
- tail->iov_base = p;
- tail->iov_len = 0;
-
- if (len & 3) {
- unsigned int pad = 4 - (len & 3);
-
- *p = 0;
- tail->iov_base = (char *)p + (len & 3);
- tail->iov_len = pad;
- len += pad;
- }
- xdr->buflen += len;
- xdr->len += len;
-}
-EXPORT_SYMBOL_GPL(xdr_encode_pages);
-
-void
xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
struct page **pages, unsigned int base, unsigned int len)
{
@@ -180,7 +152,9 @@ EXPORT_SYMBOL_GPL(xdr_inline_pages);
/*
* Helper routines for doing 'memmove' like operations on a struct xdr_buf
- *
+ */
+
+/**
* _shift_data_right_pages
* @pages: vector of pages containing both the source and dest memory area.
* @pgto_base: page vector address of destination
@@ -242,7 +216,7 @@ _shift_data_right_pages(struct page **pages, size_t pgto_base,
} while ((len -= copy) != 0);
}
-/*
+/**
* _copy_to_pages
* @pages: array of pages
* @pgbase: page vector address of destination
@@ -286,7 +260,7 @@ _copy_to_pages(struct page **pages, size_t pgbase, const char *p, size_t len)
flush_dcache_page(*pgto);
}
-/*
+/**
* _copy_from_pages
* @p: pointer to destination
* @pages: array of pages
@@ -326,7 +300,7 @@ _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
}
EXPORT_SYMBOL_GPL(_copy_from_pages);
-/*
+/**
* xdr_shrink_bufhead
* @buf: xdr_buf
* @len: bytes to remove from buf->head[0]
@@ -399,7 +373,7 @@ xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
buf->len = buf->buflen;
}
-/*
+/**
* xdr_shrink_pagelen
* @buf: xdr_buf
* @len: bytes to remove from buf->pages
@@ -455,6 +429,16 @@ xdr_shift_buf(struct xdr_buf *buf, size_t len)
EXPORT_SYMBOL_GPL(xdr_shift_buf);
/**
+ * xdr_stream_pos - Return the current offset from the start of the xdr_stream
+ * @xdr: pointer to struct xdr_stream
+ */
+unsigned int xdr_stream_pos(const struct xdr_stream *xdr)
+{
+ return (unsigned int)(XDR_QUADLEN(xdr->buf->len) - xdr->nwords) << 2;
+}
+EXPORT_SYMBOL_GPL(xdr_stream_pos);
+
+/**
* xdr_init_encode - Initialize a struct xdr_stream for sending data.
* @xdr: pointer to xdr_stream struct
* @buf: pointer to XDR buffer in which to encode data
@@ -554,13 +538,11 @@ void xdr_write_pages(struct xdr_stream *xdr, struct page **pages, unsigned int b
EXPORT_SYMBOL_GPL(xdr_write_pages);
static void xdr_set_iov(struct xdr_stream *xdr, struct kvec *iov,
- __be32 *p, unsigned int len)
+ unsigned int len)
{
if (len > iov->iov_len)
len = iov->iov_len;
- if (p == NULL)
- p = (__be32*)iov->iov_base;
- xdr->p = p;
+ xdr->p = (__be32*)iov->iov_base;
xdr->end = (__be32*)(iov->iov_base + len);
xdr->iov = iov;
xdr->page_ptr = NULL;
@@ -607,7 +589,7 @@ static void xdr_set_next_page(struct xdr_stream *xdr)
newbase -= xdr->buf->page_base;
if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0)
- xdr_set_iov(xdr, xdr->buf->tail, NULL, xdr->buf->len);
+ xdr_set_iov(xdr, xdr->buf->tail, xdr->buf->len);
}
static bool xdr_set_next_buffer(struct xdr_stream *xdr)
@@ -616,7 +598,7 @@ static bool xdr_set_next_buffer(struct xdr_stream *xdr)
xdr_set_next_page(xdr);
else if (xdr->iov == xdr->buf->head) {
if (xdr_set_page_base(xdr, 0, PAGE_SIZE) < 0)
- xdr_set_iov(xdr, xdr->buf->tail, NULL, xdr->buf->len);
+ xdr_set_iov(xdr, xdr->buf->tail, xdr->buf->len);
}
return xdr->p != xdr->end;
}
@@ -632,10 +614,15 @@ void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
xdr->buf = buf;
xdr->scratch.iov_base = NULL;
xdr->scratch.iov_len = 0;
+ xdr->nwords = XDR_QUADLEN(buf->len);
if (buf->head[0].iov_len != 0)
- xdr_set_iov(xdr, buf->head, p, buf->len);
+ xdr_set_iov(xdr, buf->head, buf->len);
else if (buf->page_len != 0)
xdr_set_page_base(xdr, 0, buf->len);
+ if (p != NULL && p > xdr->p && xdr->end >= p) {
+ xdr->nwords -= p - xdr->p;
+ xdr->p = p;
+ }
}
EXPORT_SYMBOL_GPL(xdr_init_decode);
@@ -660,12 +647,14 @@ EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
static __be32 * __xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
{
+ unsigned int nwords = XDR_QUADLEN(nbytes);
__be32 *p = xdr->p;
- __be32 *q = p + XDR_QUADLEN(nbytes);
+ __be32 *q = p + nwords;
- if (unlikely(q > xdr->end || q < p))
+ if (unlikely(nwords > xdr->nwords || q > xdr->end || q < p))
return NULL;
xdr->p = q;
+ xdr->nwords -= nwords;
return p;
}
@@ -732,6 +721,31 @@ __be32 * xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes)
}
EXPORT_SYMBOL_GPL(xdr_inline_decode);
+static unsigned int xdr_align_pages(struct xdr_stream *xdr, unsigned int len)
+{
+ struct xdr_buf *buf = xdr->buf;
+ struct kvec *iov;
+ unsigned int nwords = XDR_QUADLEN(len);
+ unsigned int cur = xdr_stream_pos(xdr);
+
+ if (xdr->nwords == 0)
+ return 0;
+ if (nwords > xdr->nwords) {
+ nwords = xdr->nwords;
+ len = nwords << 2;
+ }
+ /* Realign pages to current pointer position */
+ iov = buf->head;
+ if (iov->iov_len > cur)
+ xdr_shrink_bufhead(buf, iov->iov_len - cur);
+
+ /* Truncate page data and move it into the tail */
+ if (buf->page_len > len)
+ xdr_shrink_pagelen(buf, buf->page_len - len);
+ xdr->nwords = XDR_QUADLEN(buf->len - cur);
+ return len;
+}
+
/**
* xdr_read_pages - Ensure page-based XDR data to decode is aligned at current pointer position
* @xdr: pointer to xdr_stream struct
@@ -740,39 +754,37 @@ EXPORT_SYMBOL_GPL(xdr_inline_decode);
* Moves data beyond the current pointer position from the XDR head[] buffer
* into the page list. Any data that lies beyond current position + "len"
* bytes is moved into the XDR tail[].
+ *
+ * Returns the number of XDR encoded bytes now contained in the pages
*/
-void xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
+unsigned int xdr_read_pages(struct xdr_stream *xdr, unsigned int len)
{
struct xdr_buf *buf = xdr->buf;
struct kvec *iov;
- ssize_t shift;
+ unsigned int nwords;
unsigned int end;
- int padding;
-
- /* Realign pages to current pointer position */
- iov = buf->head;
- shift = iov->iov_len + (char *)iov->iov_base - (char *)xdr->p;
- if (shift > 0)
- xdr_shrink_bufhead(buf, shift);
+ unsigned int padding;
- /* Truncate page data and move it into the tail */
- if (buf->page_len > len)
- xdr_shrink_pagelen(buf, buf->page_len - len);
- padding = (XDR_QUADLEN(len) << 2) - len;
+ len = xdr_align_pages(xdr, len);
+ if (len == 0)
+ return 0;
+ nwords = XDR_QUADLEN(len);
+ padding = (nwords << 2) - len;
xdr->iov = iov = buf->tail;
/* Compute remaining message length. */
- end = iov->iov_len;
- shift = buf->buflen - buf->len;
- if (shift < end)
- end -= shift;
- else if (shift > 0)
- end = 0;
+ end = ((xdr->nwords - nwords) << 2) + padding;
+ if (end > iov->iov_len)
+ end = iov->iov_len;
+
/*
* Position current pointer at beginning of tail, and
* set remaining message length.
*/
xdr->p = (__be32 *)((char *)iov->iov_base + padding);
xdr->end = (__be32 *)((char *)iov->iov_base + end);
+ xdr->page_ptr = NULL;
+ xdr->nwords = XDR_QUADLEN(end - padding);
+ return len;
}
EXPORT_SYMBOL_GPL(xdr_read_pages);
@@ -788,12 +800,13 @@ EXPORT_SYMBOL_GPL(xdr_read_pages);
*/
void xdr_enter_page(struct xdr_stream *xdr, unsigned int len)
{
- xdr_read_pages(xdr, len);
+ len = xdr_align_pages(xdr, len);
/*
* Position current pointer at beginning of tail, and
* set remaining message length.
*/
- xdr_set_page_base(xdr, 0, len);
+ if (len != 0)
+ xdr_set_page_base(xdr, 0, len);
}
EXPORT_SYMBOL_GPL(xdr_enter_page);