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Commit 16e5e90f authored by Trond Myklebust's avatar Trond Myklebust
Browse files

SUNRPC: Fix up handling of the XDRBUF_SPARSE_PAGES flag 



If the allocator fails before it has reached the target number of pages,
then we need to recheck that we're not seeking past the page buffer.

Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent c4433055

net/sunrpc/xprtsock.c

+11 −11
Original line number Diff line number Diff line
@@ -330,18 +330,16 @@ xs_alloc_sparse_pages(struct xdr_buf *buf, size_t want, gfp_t gfp) 
{

	size_t i,n;



	if (!(buf->flags & XDRBUF_SPARSE_PAGES))

	if (!want || !(buf->flags & XDRBUF_SPARSE_PAGES))

		return want;

	if (want > buf->page_len)

		want = buf->page_len;

	n = (buf->page_base + want + PAGE_SIZE - 1) >> PAGE_SHIFT;

	for (i = 0; i < n; i++) {

		if (buf->pages[i])

			continue;

		buf->bvec[i].bv_page = buf->pages[i] = alloc_page(gfp);

		if (!buf->pages[i]) {

			buf->page_len = (i * PAGE_SIZE) - buf->page_base;

			return buf->page_len;

			i *= PAGE_SIZE;

			return i > buf->page_base ? i - buf->page_base : 0;

		}

	}

	return want;
@@ -404,10 +402,11 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, 
		seek -= buf->head[0].iov_len;

		offset += buf->head[0].iov_len;

	}

	if (seek < buf->page_len) {



	want = xs_alloc_sparse_pages(buf,

			min_t(size_t, count - offset, buf->page_len),

			GFP_NOWAIT);

	if (seek < want) {

		ret = xs_read_bvec(sock, msg, flags, buf->bvec,

				xdr_buf_pagecount(buf),

				want + buf->page_base,
@@ -421,9 +420,10 @@ xs_read_xdr_buf(struct socket *sock, struct msghdr *msg, int flags, 
			goto out;

		seek = 0;

	} else {

		seek -= buf->page_len;

		offset += buf->page_len;

		seek -= want;

		offset += want;

	}



	if (seek < buf->tail[0].iov_len) {

		want = min_t(size_t, count - offset, buf->tail[0].iov_len);

		ret = xs_read_kvec(sock, msg, flags, &buf->tail[0], want, seek);