[PATCH v5 12/19] sunrpc: Adjust size of socket's receive page array dynamically

cel
2025-05-09T19:04:07Z

As a step towards making NFSD's maximum rsize and wsize variable at
run-time, make sk_pages a flexible array.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
---
include/linux/sunrpc/svcsock.h | 4 +++-
net/sunrpc/svcsock.c | 8 ++++++--
2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h
index bf45d9e8492a..963bbe251e52 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -40,7 +40,9 @@ struct svc_sock {

struct completion sk_handshake_done;

- struct page * sk_pages[RPCSVC_MAXPAGES]; /* received data */
+ /* received data */
+ unsigned long sk_maxpages;
+ struct page * sk_pages[] __counted_by(sk_maxpages);
};

static inline u32 svc_sock_reclen(struct svc_sock *svsk)
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index d9fdc6ae8020..e1c85123b445 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1339,7 +1339,8 @@ static void svc_tcp_init(struct svc_sock *svsk, struct svc_serv *serv)
svsk->sk_marker = xdr_zero;
svsk->sk_tcplen = 0;
svsk->sk_datalen = 0;
- memset(&svsk->sk_pages[0], 0, sizeof(svsk->sk_pages));
+ memset(&svsk->sk_pages[0], 0,
+ svsk->sk_maxpages * sizeof(struct page *));

tcp_sock_set_nodelay(sk);

@@ -1378,10 +1379,13 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv,
struct svc_sock *svsk;
struct sock *inet;
int pmap_register = !(flags & SVC_SOCK_ANONYMOUS);
+ unsigned long pages;

- svsk = kzalloc(sizeof(*svsk), GFP_KERNEL);
+ pages = svc_serv_maxpages(serv);
+ svsk = kzalloc(struct_size(svsk, sk_pages, pages), GFP_KERNEL);
if (!svsk)
return ERR_PTR(-ENOMEM);
+ svsk->sk_maxpages = pages;

inet = sock->sk;

--
2.49.0