Subject: [PATCH v4 13/30] xprtrdma: Recognize XDRBUF_SPARSE_PAGES
From:   Chuck Lever <chuck.lever@oracle.com>
To:     linux-rdma@vger.kernel.org, linux-nfs@vger.kernel.org
Date:   Mon, 17 Dec 2018 11:40:30 -0500
Message-ID: <20181217164030.24133.8079.stgit@manet.1015granger.net>
In-Reply-To: <20181217162406.24133.27356.stgit@manet.1015granger.net>
References: <20181217162406.24133.27356.stgit@manet.1015granger.net>
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Commit 431f6eb3570f ("SUNRPC: Add a label for RPC calls that require
allocation on receive") didn't update similar logic in rpc_rdma.c.
I don't think this is a bug, per-se; the commit just adds more
careful checking for broken upper layer behavior.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
 net/sunrpc/xprtrdma/rpc_rdma.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/net/sunrpc/xprtrdma/rpc_rdma.c b/net/sunrpc/xprtrdma/rpc_rdma.c
index 3804fb3..939f84a 100644
--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -218,11 +218,12 @@ static bool rpcrdma_results_inline(struct rpcrdma_xprt *r_xprt,
 	ppages = xdrbuf->pages + (xdrbuf->page_base >> PAGE_SHIFT);
 	page_base = offset_in_page(xdrbuf->page_base);
 	while (len) {
-		if (unlikely(!*ppages)) {
-			/* XXX: Certain upper layer operations do
-			 *	not provide receive buffer pages.
-			 */
-			*ppages = alloc_page(GFP_ATOMIC);
+		/* ACL likes to be lazy in allocating pages - ACLs
+		 * are small by default but can get huge.
+		 */
+		if (unlikely(xdrbuf->flags & XDRBUF_SPARSE_PAGES)) {
+			if (!*ppages)
+				*ppages = alloc_page(GFP_ATOMIC);
 			if (!*ppages)
 				return -ENOBUFS;
 		}