diff options
| -rw-r--r-- | net/sunrpc/xdr.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 2e91fbd70f11..60d4442c5273 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -478,16 +478,47 @@ static void xdr_buf_pages_zero(const struct xdr_buf *buf, unsigned int pgbase, } while ((len -= zero) != 0); } +static unsigned int xdr_buf_pages_fill_sparse(const struct xdr_buf *buf, + unsigned int buflen, gfp_t gfp) +{ + unsigned int i, npages, pagelen; + + if (!(buf->flags & XDRBUF_SPARSE_PAGES)) + return buflen; + if (buflen <= buf->head->iov_len) + return buflen; + pagelen = buflen - buf->head->iov_len; + if (pagelen > buf->page_len) + pagelen = buf->page_len; + npages = (pagelen + buf->page_base + PAGE_SIZE - 1) >> PAGE_SHIFT; + for (i = 0; i < npages; i++) { + if (!buf->pages[i]) + continue; + buf->pages[i] = alloc_page(gfp); + if (likely(buf->pages[i])) + continue; + buflen -= pagelen; + pagelen = i << PAGE_SHIFT; + if (pagelen > buf->page_base) + buflen += pagelen - buf->page_base; + break; + } + return buflen; +} + static void xdr_buf_try_expand(struct xdr_buf *buf, unsigned int len) { struct kvec *head = buf->head; struct kvec *tail = buf->tail; unsigned int sum = head->iov_len + buf->page_len + tail->iov_len; - unsigned int free_space; + unsigned int free_space, newlen; if (sum > buf->len) { free_space = min_t(unsigned int, sum - buf->len, len); - buf->len += free_space; + newlen = xdr_buf_pages_fill_sparse(buf, buf->len + free_space, + GFP_KERNEL); + free_space = newlen - buf->len; + buf->len = newlen; len -= free_space; if (!len) return; |