[PATCH net-next v5 13/14] tls/device: Support MSG_SPLICE_PAGES

David Howells
2023-06-07T16:26:35Z

Make TLS's device sendmsg() support MSG_SPLICE_PAGES. This causes pages to
be spliced from the source iterator if possible.

This allows ->sendpage() to be replaced by something that can handle
multiple multipage folios in a single transaction.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chuck Lever <chuck.lever@oracle.com>
cc: Boris Pismenny <borisp@nvidia.com>
cc: John Fastabend <john.fastabend@gmail.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: Eric Dumazet <edumazet@google.com>
cc: "David S. Miller" <davem@davemloft.net>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: netdev@vger.kernel.org
---
net/tls/tls_device.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/net/tls/tls_device.c b/net/tls/tls_device.c
index 439be833dcf9..bb3bb523544e 100644
--- a/net/tls/tls_device.c
+++ b/net/tls/tls_device.c
@@ -509,6 +509,29 @@ static int tls_push_data(struct sock *sk,
tls_append_frag(record, &zc_pfrag, copy);

iter_offset.offset += copy;
+ } else if (copy && (flags & MSG_SPLICE_PAGES)) {
+ struct page_frag zc_pfrag;
+ struct page **pages = &zc_pfrag.page;
+ size_t off;
+
+ rc = iov_iter_extract_pages(iter_offset.msg_iter,
+ &pages, copy, 1, 0, &off);
+ if (rc <= 0) {
+ if (rc == 0)
+ rc = -EIO;
+ goto handle_error;
+ }
+ copy = rc;
+
+ if (WARN_ON_ONCE(!sendpage_ok(zc_pfrag.page))) {
+ iov_iter_revert(iter_offset.msg_iter, copy);
+ rc = -EIO;
+ goto handle_error;
+ }
+
+ zc_pfrag.offset = off;
+ zc_pfrag.size = copy;
+ tls_append_frag(record, &zc_pfrag, copy);
} else if (copy) {
copy = min_t(size_t, copy, pfrag->size - pfrag->offset);

@@ -572,6 +595,9 @@ int tls_device_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
union tls_iter_offset iter;
int rc;

+ if (!tls_ctx->zerocopy_sendfile)
+ msg->msg_flags &= ~MSG_SPLICE_PAGES;
+
mutex_lock(&tls_ctx->tx_lock);
lock_sock(sk);