From ea08eeccae9297f7aabd2ef7f0c2517ac4549acc Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:18:26 +0000
Subject: [PATCH] write in 30M
---
kernel/net/sunrpc/xdr.c | 516 ++++++++++++++++++++++++++++++++++++++++++++++----------
1 files changed, 419 insertions(+), 97 deletions(-)
diff --git a/kernel/net/sunrpc/xdr.c b/kernel/net/sunrpc/xdr.c
index 540e340..d84bb50 100644
--- a/kernel/net/sunrpc/xdr.c
+++ b/kernel/net/sunrpc/xdr.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/net/sunrpc/xdr.c
*
@@ -15,6 +16,11 @@
#include <linux/errno.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/msg_prot.h>
+#include <linux/bvec.h>
+#include <trace/events/sunrpc.h>
+
+static void _copy_to_pages(struct page **, size_t, const char *, size_t);
+
/*
* XDR functions for basic NFS types
@@ -128,6 +134,48 @@
}
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;
+}
+
+/**
+ * xdr_inline_pages - Prepare receive buffer for a large reply
+ * @xdr: xdr_buf into which reply will be placed
+ * @offset: expected offset where data payload will start, in bytes
+ * @pages: vector of struct page pointers
+ * @base: offset in first page where receive should start, in bytes
+ * @len: expected size of the upper layer data payload, in bytes
+ *
+ */
void
xdr_inline_pages(struct xdr_buf *xdr, unsigned int offset,
struct page **pages, unsigned int base, unsigned int len)
@@ -145,6 +193,8 @@
tail->iov_base = buf + offset;
tail->iov_len = buflen - offset;
+ if ((xdr->page_len & 3) == 0)
+ tail->iov_len -= sizeof(__be32);
xdr->buflen += len;
}
@@ -153,6 +203,88 @@
/*
* Helper routines for doing 'memmove' like operations on a struct xdr_buf
*/
+
+/**
+ * _shift_data_left_pages
+ * @pages: vector of pages containing both the source and dest memory area.
+ * @pgto_base: page vector address of destination
+ * @pgfrom_base: page vector address of source
+ * @len: number of bytes to copy
+ *
+ * Note: the addresses pgto_base and pgfrom_base are both calculated in
+ * the same way:
+ * if a memory area starts at byte 'base' in page 'pages[i]',
+ * then its address is given as (i << PAGE_CACHE_SHIFT) + base
+ * Alse note: pgto_base must be < pgfrom_base, but the memory areas
+ * they point to may overlap.
+ */
+static void
+_shift_data_left_pages(struct page **pages, size_t pgto_base,
+ size_t pgfrom_base, size_t len)
+{
+ struct page **pgfrom, **pgto;
+ char *vfrom, *vto;
+ size_t copy;
+
+ BUG_ON(pgfrom_base <= pgto_base);
+
+ pgto = pages + (pgto_base >> PAGE_SHIFT);
+ pgfrom = pages + (pgfrom_base >> PAGE_SHIFT);
+
+ pgto_base &= ~PAGE_MASK;
+ pgfrom_base &= ~PAGE_MASK;
+
+ do {
+ if (pgto_base >= PAGE_SIZE) {
+ pgto_base = 0;
+ pgto++;
+ }
+ if (pgfrom_base >= PAGE_SIZE){
+ pgfrom_base = 0;
+ pgfrom++;
+ }
+
+ copy = len;
+ if (copy > (PAGE_SIZE - pgto_base))
+ copy = PAGE_SIZE - pgto_base;
+ if (copy > (PAGE_SIZE - pgfrom_base))
+ copy = PAGE_SIZE - pgfrom_base;
+
+ vto = kmap_atomic(*pgto);
+ if (*pgto != *pgfrom) {
+ vfrom = kmap_atomic(*pgfrom);
+ memcpy(vto + pgto_base, vfrom + pgfrom_base, copy);
+ kunmap_atomic(vfrom);
+ } else
+ memmove(vto + pgto_base, vto + pgfrom_base, copy);
+ flush_dcache_page(*pgto);
+ kunmap_atomic(vto);
+
+ pgto_base += copy;
+ pgfrom_base += copy;
+
+ } while ((len -= copy) != 0);
+}
+
+static void
+_shift_data_left_tail(struct xdr_buf *buf, unsigned int pgto, size_t len)
+{
+ struct kvec *tail = buf->tail;
+
+ if (len > tail->iov_len)
+ len = tail->iov_len;
+
+ _copy_to_pages(buf->pages,
+ buf->page_base + pgto,
+ (char *)tail->iov_base,
+ len);
+ tail->iov_len -= len;
+
+ if (tail->iov_len > 0)
+ memmove((char *)tail->iov_base,
+ tail->iov_base + len,
+ tail->iov_len);
+}
/**
* _shift_data_right_pages
@@ -217,6 +349,46 @@
kunmap_atomic(vto);
} while ((len -= copy) != 0);
+}
+
+static unsigned int
+_shift_data_right_tail(struct xdr_buf *buf, unsigned int pgfrom, size_t len)
+{
+ struct kvec *tail = buf->tail;
+ unsigned int tailbuf_len;
+ unsigned int result = 0;
+ size_t copy;
+
+ tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len;
+
+ /* Shift the tail first */
+ if (tailbuf_len != 0) {
+ unsigned int free_space = tailbuf_len - tail->iov_len;
+
+ if (len < free_space)
+ free_space = len;
+ if (len > free_space)
+ len = free_space;
+
+ tail->iov_len += free_space;
+ copy = len;
+
+ if (tail->iov_len > len) {
+ char *p = (char *)tail->iov_base + len;
+ memmove(p, tail->iov_base, tail->iov_len - free_space);
+ result += tail->iov_len - free_space;
+ } else
+ copy = tail->iov_len;
+
+ /* Copy from the inlined pages into the tail */
+ _copy_from_pages((char *)tail->iov_base,
+ buf->pages,
+ buf->page_base + pgfrom,
+ copy);
+ result += copy;
+ }
+
+ return result;
}
/**
@@ -304,6 +476,38 @@
EXPORT_SYMBOL_GPL(_copy_from_pages);
/**
+ * _zero_pages
+ * @pages: array of pages
+ * @pgbase: beginning page vector address
+ * @len: length
+ */
+static void
+_zero_pages(struct page **pages, size_t pgbase, size_t len)
+{
+ struct page **page;
+ char *vpage;
+ size_t zero;
+
+ page = pages + (pgbase >> PAGE_SHIFT);
+ pgbase &= ~PAGE_MASK;
+
+ do {
+ zero = PAGE_SIZE - pgbase;
+ if (zero > len)
+ zero = len;
+
+ vpage = kmap_atomic(*page);
+ memset(vpage + pgbase, 0, zero);
+ kunmap_atomic(vpage);
+
+ flush_dcache_page(*page);
+ pgbase = 0;
+ page++;
+
+ } while ((len -= zero) != 0);
+}
+
+/**
* xdr_shrink_bufhead
* @buf: xdr_buf
* @len: bytes to remove from buf->head[0]
@@ -312,13 +516,15 @@
* 'len' bytes. The extra data is not lost, but is instead
* moved into the inlined pages and/or the tail.
*/
-static void
+static unsigned int
xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
{
struct kvec *head, *tail;
size_t copy, offs;
unsigned int pglen = buf->page_len;
+ unsigned int result;
+ result = 0;
tail = buf->tail;
head = buf->head;
@@ -332,6 +538,7 @@
copy = tail->iov_len - len;
memmove((char *)tail->iov_base + len,
tail->iov_base, copy);
+ result += copy;
}
/* Copy from the inlined pages into the tail */
copy = len;
@@ -342,11 +549,13 @@
copy = 0;
else if (copy > tail->iov_len - offs)
copy = tail->iov_len - offs;
- if (copy != 0)
+ if (copy != 0) {
_copy_from_pages((char *)tail->iov_base + offs,
buf->pages,
buf->page_base + pglen + offs - len,
copy);
+ result += copy;
+ }
/* Do we also need to copy data from the head into the tail ? */
if (len > pglen) {
offs = copy = len - pglen;
@@ -356,6 +565,7 @@
(char *)head->iov_base +
head->iov_len - offs,
copy);
+ result += copy;
}
}
/* Now handle pages */
@@ -371,60 +581,42 @@
_copy_to_pages(buf->pages, buf->page_base,
(char *)head->iov_base + head->iov_len - len,
copy);
+ result += copy;
}
head->iov_len -= len;
buf->buflen -= len;
/* Have we truncated the message? */
if (buf->len > buf->buflen)
buf->len = buf->buflen;
+
+ return result;
}
/**
- * xdr_shrink_pagelen
+ * xdr_shrink_pagelen - shrinks buf->pages by up to @len bytes
* @buf: xdr_buf
* @len: bytes to remove from buf->pages
*
- * Shrinks XDR buffer's page array buf->pages by
- * 'len' bytes. The extra data is not lost, but is instead
- * moved into the tail.
+ * The extra data is not lost, but is instead moved into buf->tail.
+ * Returns the actual number of bytes moved.
*/
-static void
+static unsigned int
xdr_shrink_pagelen(struct xdr_buf *buf, size_t len)
{
- struct kvec *tail;
- size_t copy;
unsigned int pglen = buf->page_len;
- unsigned int tailbuf_len;
+ unsigned int result;
- tail = buf->tail;
- BUG_ON (len > pglen);
+ if (len > buf->page_len)
+ len = buf-> page_len;
- tailbuf_len = buf->buflen - buf->head->iov_len - buf->page_len;
-
- /* Shift the tail first */
- if (tailbuf_len != 0) {
- unsigned int free_space = tailbuf_len - tail->iov_len;
-
- if (len < free_space)
- free_space = len;
- tail->iov_len += free_space;
-
- copy = len;
- if (tail->iov_len > len) {
- char *p = (char *)tail->iov_base + len;
- memmove(p, tail->iov_base, tail->iov_len - len);
- } else
- copy = tail->iov_len;
- /* Copy from the inlined pages into the tail */
- _copy_from_pages((char *)tail->iov_base,
- buf->pages, buf->page_base + pglen - len,
- copy);
- }
+ result = _shift_data_right_tail(buf, pglen - len, len);
buf->page_len -= len;
buf->buflen -= len;
/* Have we truncated the message? */
if (buf->len > buf->buflen)
buf->len = buf->buflen;
+
+ return result;
}
void
@@ -445,10 +637,24 @@
EXPORT_SYMBOL_GPL(xdr_stream_pos);
/**
+ * xdr_page_pos - Return the current offset from the start of the xdr pages
+ * @xdr: pointer to struct xdr_stream
+ */
+unsigned int xdr_page_pos(const struct xdr_stream *xdr)
+{
+ unsigned int pos = xdr_stream_pos(xdr);
+
+ WARN_ON(pos < xdr->buf->head[0].iov_len);
+ return pos - xdr->buf->head[0].iov_len;
+}
+EXPORT_SYMBOL_GPL(xdr_page_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
* @p: current pointer inside XDR buffer
+ * @rqst: pointer to controlling rpc_rqst, for debugging
*
* Note: at the moment the RPC client only passes the length of our
* scratch buffer in the xdr_buf's header kvec. Previously this
@@ -457,7 +663,8 @@
* of the buffer length, and takes care of adjusting the kvec
* length for us.
*/
-void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
+void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
+ struct rpc_rqst *rqst)
{
struct kvec *iov = buf->head;
int scratch_len = buf->buflen - buf->page_len - buf->tail[0].iov_len;
@@ -479,6 +686,7 @@
buf->len += len;
iov->iov_len += len;
}
+ xdr->rqst = rqst;
}
EXPORT_SYMBOL_GPL(xdr_init_encode);
@@ -495,7 +703,7 @@
* required at the end of encoding, or any other time when the xdr_buf
* data might be read.
*/
-void xdr_commit_encode(struct xdr_stream *xdr)
+inline void xdr_commit_encode(struct xdr_stream *xdr)
{
int shift = xdr->scratch.iov_len;
void *page;
@@ -517,9 +725,9 @@
int frag1bytes, frag2bytes;
if (nbytes > PAGE_SIZE)
- return NULL; /* Bigger buffers require special handling */
+ goto out_overflow; /* Bigger buffers require special handling */
if (xdr->buf->len + nbytes > xdr->buf->buflen)
- return NULL; /* Sorry, we're totally out of space */
+ goto out_overflow; /* Sorry, we're totally out of space */
frag1bytes = (xdr->end - xdr->p) << 2;
frag2bytes = nbytes - frag1bytes;
if (xdr->iov)
@@ -544,10 +752,17 @@
*/
xdr->p = (void *)p + frag2bytes;
space_left = xdr->buf->buflen - xdr->buf->len;
- xdr->end = (void *)p + min_t(int, space_left, PAGE_SIZE);
+ if (space_left - frag1bytes >= PAGE_SIZE)
+ xdr->end = (void *)p + PAGE_SIZE;
+ else
+ xdr->end = (void *)p + space_left - frag1bytes;
+
xdr->buf->page_len += frag2bytes;
xdr->buf->len += nbytes;
return p;
+out_overflow:
+ trace_rpc_xdr_overflow(xdr, nbytes);
+ return NULL;
}
/**
@@ -581,6 +796,51 @@
}
EXPORT_SYMBOL_GPL(xdr_reserve_space);
+
+/**
+ * xdr_reserve_space_vec - Reserves a large amount of buffer space for sending
+ * @xdr: pointer to xdr_stream
+ * @vec: pointer to a kvec array
+ * @nbytes: number of bytes to reserve
+ *
+ * Reserves enough buffer space to encode 'nbytes' of data and stores the
+ * pointers in 'vec'. The size argument passed to xdr_reserve_space() is
+ * determined based on the number of bytes remaining in the current page to
+ * avoid invalidating iov_base pointers when xdr_commit_encode() is called.
+ */
+int xdr_reserve_space_vec(struct xdr_stream *xdr, struct kvec *vec, size_t nbytes)
+{
+ int thislen;
+ int v = 0;
+ __be32 *p;
+
+ /*
+ * svcrdma requires every READ payload to start somewhere
+ * in xdr->pages.
+ */
+ if (xdr->iov == xdr->buf->head) {
+ xdr->iov = NULL;
+ xdr->end = xdr->p;
+ }
+
+ while (nbytes) {
+ thislen = xdr->buf->page_len % PAGE_SIZE;
+ thislen = min_t(size_t, nbytes, PAGE_SIZE - thislen);
+
+ p = xdr_reserve_space(xdr, thislen);
+ if (!p)
+ return -EIO;
+
+ vec[v].iov_base = p;
+ vec[v].iov_len = thislen;
+ v++;
+ nbytes -= thislen;
+ }
+
+ return v;
+}
+EXPORT_SYMBOL_GPL(xdr_reserve_space_vec);
+
/**
* xdr_truncate_encode - truncate an encode buffer
* @xdr: pointer to xdr_stream
@@ -591,7 +851,7 @@
* head, tail, and page lengths are adjusted to correspond.
*
* If this means moving xdr->p to a different buffer, we assume that
- * that the end pointer should be set to the end of the current page,
+ * the end pointer should be set to the end of the current page,
* except in the case of the head buffer when we assume the head
* buffer's current length represents the end of the available buffer.
*
@@ -758,6 +1018,13 @@
return 0;
}
+static void xdr_set_page(struct xdr_stream *xdr, unsigned int base,
+ unsigned int len)
+{
+ if (xdr_set_page_base(xdr, base, len) < 0)
+ xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2);
+}
+
static void xdr_set_next_page(struct xdr_stream *xdr)
{
unsigned int newbase;
@@ -765,8 +1032,7 @@
newbase = (1 + xdr->page_ptr - xdr->buf->pages) << PAGE_SHIFT;
newbase -= xdr->buf->page_base;
- if (xdr_set_page_base(xdr, newbase, PAGE_SIZE) < 0)
- xdr_set_iov(xdr, xdr->buf->tail, xdr->nwords << 2);
+ xdr_set_page(xdr, newbase, PAGE_SIZE);
}
static bool xdr_set_next_buffer(struct xdr_stream *xdr)
@@ -774,8 +1040,7 @@
if (xdr->page_ptr != NULL)
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, xdr->nwords << 2);
+ xdr_set_page(xdr, 0, PAGE_SIZE);
}
return xdr->p != xdr->end;
}
@@ -785,8 +1050,10 @@
* @xdr: pointer to xdr_stream struct
* @buf: pointer to XDR buffer from which to decode data
* @p: current pointer inside XDR buffer
+ * @rqst: pointer to controlling rpc_rqst, for debugging
*/
-void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p)
+void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p,
+ struct rpc_rqst *rqst)
{
xdr->buf = buf;
xdr->scratch.iov_base = NULL;
@@ -802,6 +1069,7 @@
xdr->nwords -= p - xdr->p;
xdr->p = p;
}
+ xdr->rqst = rqst;
}
EXPORT_SYMBOL_GPL(xdr_init_decode);
@@ -820,7 +1088,7 @@
buf->page_len = len;
buf->buflen = len;
buf->len = len;
- xdr_init_decode(xdr, buf, NULL);
+ xdr_init_decode(xdr, buf, NULL, NULL);
}
EXPORT_SYMBOL_GPL(xdr_init_decode_pages);
@@ -862,20 +1130,23 @@
size_t cplen = (char *)xdr->end - (char *)xdr->p;
if (nbytes > xdr->scratch.iov_len)
- return NULL;
+ goto out_overflow;
p = __xdr_inline_decode(xdr, cplen);
if (p == NULL)
return NULL;
memcpy(cpdest, p, cplen);
+ if (!xdr_set_next_buffer(xdr))
+ goto out_overflow;
cpdest += cplen;
nbytes -= cplen;
- if (!xdr_set_next_buffer(xdr))
- return NULL;
p = __xdr_inline_decode(xdr, nbytes);
if (p == NULL)
return NULL;
memcpy(cpdest, p, nbytes);
return xdr->scratch.iov_base;
+out_overflow:
+ trace_rpc_xdr_overflow(xdr, nbytes);
+ return NULL;
}
/**
@@ -892,33 +1163,47 @@
{
__be32 *p;
- if (nbytes == 0)
+ if (unlikely(nbytes == 0))
return xdr->p;
if (xdr->p == xdr->end && !xdr_set_next_buffer(xdr))
- return NULL;
+ goto out_overflow;
p = __xdr_inline_decode(xdr, nbytes);
if (p != NULL)
return p;
return xdr_copy_to_scratch(xdr, nbytes);
+out_overflow:
+ trace_rpc_xdr_overflow(xdr, nbytes);
+ return NULL;
}
EXPORT_SYMBOL_GPL(xdr_inline_decode);
+
+static void xdr_realign_pages(struct xdr_stream *xdr)
+{
+ struct xdr_buf *buf = xdr->buf;
+ struct kvec *iov = buf->head;
+ unsigned int cur = xdr_stream_pos(xdr);
+ unsigned int copied, offset;
+
+ /* Realign pages to current pointer position */
+ if (iov->iov_len > cur) {
+ offset = iov->iov_len - cur;
+ copied = xdr_shrink_bufhead(buf, offset);
+ trace_rpc_xdr_alignment(xdr, offset, copied);
+ xdr->nwords = XDR_QUADLEN(buf->len - cur);
+ }
+}
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);
+ unsigned int copied, offset;
if (xdr->nwords == 0)
return 0;
- /* Realign pages to current pointer position */
- iov = buf->head;
- if (iov->iov_len > cur) {
- xdr_shrink_bufhead(buf, iov->iov_len - cur);
- xdr->nwords = XDR_QUADLEN(buf->len - cur);
- }
+ xdr_realign_pages(xdr);
if (nwords > xdr->nwords) {
nwords = xdr->nwords;
len = nwords << 2;
@@ -927,7 +1212,9 @@
len = buf->page_len;
else if (nwords < xdr->nwords) {
/* Truncate page data and move it into the tail */
- xdr_shrink_pagelen(buf, buf->page_len - len);
+ offset = buf->page_len - len;
+ copied = xdr_shrink_pagelen(buf, offset);
+ trace_rpc_xdr_alignment(xdr, offset, copied);
xdr->nwords = XDR_QUADLEN(buf->len - cur);
}
return len;
@@ -975,6 +1262,79 @@
}
EXPORT_SYMBOL_GPL(xdr_read_pages);
+uint64_t xdr_align_data(struct xdr_stream *xdr, uint64_t offset, uint32_t length)
+{
+ struct xdr_buf *buf = xdr->buf;
+ unsigned int from, bytes;
+ unsigned int shift = 0;
+
+ if ((offset + length) < offset ||
+ (offset + length) > buf->page_len)
+ length = buf->page_len - offset;
+
+ xdr_realign_pages(xdr);
+ from = xdr_page_pos(xdr);
+ bytes = xdr->nwords << 2;
+ if (length < bytes)
+ bytes = length;
+
+ /* Move page data to the left */
+ if (from > offset) {
+ shift = min_t(unsigned int, bytes, buf->page_len - from);
+ _shift_data_left_pages(buf->pages,
+ buf->page_base + offset,
+ buf->page_base + from,
+ shift);
+ bytes -= shift;
+
+ /* Move tail data into the pages, if necessary */
+ if (bytes > 0)
+ _shift_data_left_tail(buf, offset + shift, bytes);
+ }
+
+ xdr->nwords -= XDR_QUADLEN(length);
+ xdr_set_page(xdr, from + length, PAGE_SIZE);
+ return length;
+}
+EXPORT_SYMBOL_GPL(xdr_align_data);
+
+uint64_t xdr_expand_hole(struct xdr_stream *xdr, uint64_t offset, uint64_t length)
+{
+ struct xdr_buf *buf = xdr->buf;
+ unsigned int bytes;
+ unsigned int from;
+ unsigned int truncated = 0;
+
+ if ((offset + length) < offset ||
+ (offset + length) > buf->page_len)
+ length = buf->page_len - offset;
+
+ xdr_realign_pages(xdr);
+ from = xdr_page_pos(xdr);
+ bytes = xdr->nwords << 2;
+
+ if (offset + length + bytes > buf->page_len) {
+ unsigned int shift = (offset + length + bytes) - buf->page_len;
+ unsigned int res = _shift_data_right_tail(buf, from + bytes - shift, shift);
+ truncated = shift - res;
+ xdr->nwords -= XDR_QUADLEN(truncated);
+ bytes -= shift;
+ }
+
+ /* Now move the page data over and zero pages */
+ if (bytes > 0)
+ _shift_data_right_pages(buf->pages,
+ buf->page_base + offset + length,
+ buf->page_base + from,
+ bytes);
+ _zero_pages(buf->pages, buf->page_base + offset, length);
+
+ buf->len += length - (from - offset) - truncated;
+ xdr_set_page(xdr, offset + length, PAGE_SIZE);
+ return length;
+}
+EXPORT_SYMBOL_GPL(xdr_expand_hole);
+
/**
* xdr_enter_page - decode data from the XDR page
* @xdr: pointer to xdr_stream struct
@@ -997,7 +1357,7 @@
}
EXPORT_SYMBOL_GPL(xdr_enter_page);
-static struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
+static const struct kvec empty_iov = {.iov_base = NULL, .iov_len = 0};
void
xdr_buf_from_iov(struct kvec *iov, struct xdr_buf *buf)
@@ -1197,44 +1557,6 @@
return write_bytes_to_xdr_buf(buf, base, &raw, sizeof(obj));
}
EXPORT_SYMBOL_GPL(xdr_encode_word);
-
-/* If the netobj starting offset bytes from the start of xdr_buf is contained
- * entirely in the head or the tail, set object to point to it; otherwise
- * try to find space for it at the end of the tail, copy it there, and
- * set obj to point to it. */
-int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset)
-{
- struct xdr_buf subbuf;
-
- if (xdr_decode_word(buf, offset, &obj->len))
- return -EFAULT;
- if (xdr_buf_subsegment(buf, &subbuf, offset + 4, obj->len))
- return -EFAULT;
-
- /* Is the obj contained entirely in the head? */
- obj->data = subbuf.head[0].iov_base;
- if (subbuf.head[0].iov_len == obj->len)
- return 0;
- /* ..or is the obj contained entirely in the tail? */
- obj->data = subbuf.tail[0].iov_base;
- if (subbuf.tail[0].iov_len == obj->len)
- return 0;
-
- /* use end of tail as storage for obj:
- * (We don't copy to the beginning because then we'd have
- * to worry about doing a potentially overlapping copy.
- * This assumes the object is at most half the length of the
- * tail.) */
- if (obj->len > buf->buflen - buf->len)
- return -ENOMEM;
- if (buf->tail[0].iov_len != 0)
- obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len;
- else
- obj->data = buf->head[0].iov_base + buf->head[0].iov_len;
- __read_bytes_from_xdr_buf(&subbuf, obj->data, obj->len);
- return 0;
-}
-EXPORT_SYMBOL_GPL(xdr_buf_read_netobj);
/* Returns 0 on success, or else a negative error code. */
static int
--
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