@@ -287,6 +287,7 @@ struct ucred {
#define MSG_SENDPAGE_NOTLAST 0x20000 /* sendpage() internal : not the last page */
#define MSG_BATCH 0x40000 /* sendmmsg(): more messages coming */
#define MSG_EOF MSG_FIN
+#define MSG_NO_SHARED_FRAGS 0x80000 /* sendpage() internal : page frags are not shared */
#define MSG_ZEROCOPY 0x4000000 /* Use user data in kernel path */
#define MSG_FASTOPEN 0x20000000 /* Send data in TCP SYN */
@@ -994,7 +994,9 @@ ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
get_page(page);
skb_fill_page_desc(skb, i, page, offset, copy);
}
- skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
+
+ if (!(flags & MSG_NO_SHARED_FRAGS))
+ skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
skb->len += copy;
skb->data_len += copy;
When calling do_tcp_sendpages() from in kernel and we know the data has no references from user side we can omit SKBTX_SHARED_FRAG flag. This patch adds an internal flag, NO_SKBTX_SHARED_FRAG that can be used to omit setting SKBTX_SHARED_FRAG. The flag is not exposed to userspace because the sendpage call from the splice logic masks out all bits except MSG_MORE. Signed-off-by: John Fastabend <john.fastabend@gmail.com> --- include/linux/socket.h | 1 + net/ipv4/tcp.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-)