From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andreas Gruenbacher Subject: [RFC v7 35/41] sunrpc: Allow to demand-allocate pages to encode into Date: Sat, 5 Sep 2015 12:27:30 +0200 Message-ID: <1441448856-13478-36-git-send-email-agruenba@redhat.com> References: <1441448856-13478-1-git-send-email-agruenba@redhat.com> To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-security-module-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <1441448856-13478-1-git-send-email-agruenba-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-fsdevel.vger.kernel.org When encoding large, variable-length objects such as acls into xdr_bufs, it is easier to allocate buffer pages on demand rather than precomputing the required buffer size. Signed-off-by: Andreas Gruenbacher --- net/sunrpc/xdr.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/net/sunrpc/xdr.c b/net/sunrpc/xdr.c index 4439ac4..63c1c36 100644 --- a/net/sunrpc/xdr.c +++ b/net/sunrpc/xdr.c @@ -537,6 +537,15 @@ static __be32 *xdr_get_next_encode_buffer(struct xdr_stream *xdr, */ xdr->scratch.iov_base = xdr->p; xdr->scratch.iov_len = frag1bytes; + + if (!*xdr->page_ptr) { + struct page *page = alloc_page(GFP_NOFS); + + if (!page) + return NULL; + *xdr->page_ptr = page; + } + p = page_address(*xdr->page_ptr); /* * Note this is where the next encode will start after we've -- 2.4.3