-static int
-process_xdr_buf(struct xdr_buf *buf, int offset, int len,
- int (*actor)(struct scatterlist *, void *), void *data)
-{
- int i, page_len, thislen, page_offset, ret = 0;
- 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->page = 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;
-}
-