[PATCH v10 40/46] sunrpc: Allow to demand-allocate pages to encode into

Andreas Gruenbacher
2015-10-11T23:03:50Z

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 <agruenba@redhat.com>
---
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