Update net/ to use sg helpers

[linux-2.6-omap-h63xx.git] / net / sunrpc / xdr.c

diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c
index ebdff6beba319f3b281bbf4e37f9940b1875df69..3d1f7cdf9dd015819e227bb1a1830b17ffd0972e 100644 (file)
--- a/net/sunrpc/xdr.c
+++ b/net/sunrpc/xdr.c
@@ -302,7 +302,7 @@ _copy_from_pages(char *p, struct page **pages, size_t pgbase, size_t len)
  * @buf: xdr_buf
  * @len: bytes to remove from buf->head[0]
  *
- * Shrinks XDR buffer's header kvec buf->head[0] by 
+ * Shrinks XDR buffer's header kvec buf->head[0] by
  * 'len' bytes. The extra data is not lost, but is instead
  * moved into the inlined pages and/or the tail.
  */
@@ -375,7 +375,7 @@ xdr_shrink_bufhead(struct xdr_buf *buf, size_t len)
  * @buf: xdr_buf
  * @len: bytes to remove from buf->pages
  *
- * Shrinks XDR buffer's page array buf->pages by 
+ * Shrinks XDR buffer's page array buf->pages by
  * 'len' bytes. The extra data is not lost, but is instead
  * moved into the tail.
  */
@@ -773,44 +773,37 @@ xdr_encode_word(struct xdr_buf *buf, unsigned int base, u32 obj)
  * 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)
+int xdr_buf_read_netobj(struct xdr_buf *buf, struct xdr_netobj *obj, unsigned int offset)
 {
-       unsigned int tail_offset = buf->head[0].iov_len + buf->page_len;
-       unsigned int obj_end_offset;
+       struct xdr_buf subbuf;
 
        if (xdr_decode_word(buf, offset, &obj->len))
-               goto out;
-       obj_end_offset = offset + 4 + obj->len;
-
-       if (obj_end_offset <= buf->head[0].iov_len) {
-               /* The obj is contained entirely in the head: */
-               obj->data = buf->head[0].iov_base + offset + 4;
-       } else if (offset + 4 >= tail_offset) {
-               if (obj_end_offset - tail_offset
-                               > buf->tail[0].iov_len)
-                       goto out;
-               /* The obj is contained entirely in the tail: */
-               obj->data = buf->tail[0].iov_base
-                       + offset - tail_offset + 4;
-       } else {
-               /* 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->tail[0].iov_len)
-                       goto out;
-               obj->data = buf->tail[0].iov_base + buf->tail[0].iov_len - 
-                               obj->len;
-               if (read_bytes_from_xdr_buf(buf, offset + 4,
-                                       obj->data, obj->len))
-                       goto out;
+               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;
-out:
-       return -1;
 }
 
 /* Returns 0 on success, or else a negative error code. */
@@ -1028,3 +1021,71 @@ xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
 
        return xdr_xcode_array2(buf, base, desc, 1);
 }
+
+int
+xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len,
+               int (*actor)(struct scatterlist *, void *), void *data)
+{
+       int i, ret = 0;
+       unsigned page_len, thislen, page_offset;
+       struct scatterlist      sg[1];
+
+       if (offset >= buf->head[0].iov_len) {
+               offset -= buf->head[0].iov_len;
+       } else {
+               thislen = buf->head[0].iov_len - offset;
+               if (thislen > len)
+                       thislen = len;
+               sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
+               ret = actor(sg, data);
+               if (ret)
+                       goto out;
+               offset = 0;
+               len -= thislen;
+       }
+       if (len == 0)
+               goto out;
+
+       if (offset >= buf->page_len) {
+               offset -= buf->page_len;
+       } else {
+               page_len = buf->page_len - offset;
+               if (page_len > len)
+                       page_len = len;
+               len -= page_len;
+               page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
+               i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
+               thislen = PAGE_CACHE_SIZE - page_offset;
+               do {
+                       if (thislen > page_len)
+                               thislen = page_len;
+                       sg_set_page(sg, buf->pages[i]);
+                       sg->offset = page_offset;
+                       sg->length = thislen;
+                       ret = actor(sg, data);
+                       if (ret)
+                               goto out;
+                       page_len -= thislen;
+                       i++;
+                       page_offset = 0;
+                       thislen = PAGE_CACHE_SIZE;
+               } while (page_len != 0);
+               offset = 0;
+       }
+       if (len == 0)
+               goto out;
+       if (offset < buf->tail[0].iov_len) {
+               thislen = buf->tail[0].iov_len - offset;
+               if (thislen > len)
+                       thislen = len;
+               sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
+               ret = actor(sg, data);
+               len -= thislen;
+       }
+       if (len != 0)
+               ret = -EINVAL;
+out:
+       return ret;
+}
+EXPORT_SYMBOL(xdr_process_buf);
+