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authorDavid Howells <dhowells@redhat.com>2023-05-22 13:11:20 +0100
committerJakub Kicinski <kuba@kernel.org>2023-05-23 20:48:27 -0700
commit7da0dde68486b2d5bd7c689a9b327b77efecdfd0 (patch)
tree7a55fda57d6a3d8ec2af03824676ecae302505a5
parent5367f9bbb86a9fa377f8cfc673d9b8a446f3e917 (diff)
ip, udp: Support MSG_SPLICE_PAGES
Make IP/UDP sendmsg() support MSG_SPLICE_PAGES. This causes pages to be spliced from the source iterator. 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: Willem de Bruijn <willemdebruijn.kernel@gmail.com> cc: David Ahern <dsahern@kernel.org> cc: Jens Axboe <axboe@kernel.dk> cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--net/ipv4/ip_output.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 52fc840898d8..c7db973b5d29 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1048,6 +1048,14 @@ static int __ip_append_data(struct sock *sk,
skb_zcopy_set(skb, uarg, &extra_uref);
}
}
+ } else if ((flags & MSG_SPLICE_PAGES) && length) {
+ if (inet->hdrincl)
+ return -EPERM;
+ if (rt->dst.dev->features & NETIF_F_SG)
+ /* We need an empty buffer to attach stuff to */
+ paged = true;
+ else
+ flags &= ~MSG_SPLICE_PAGES;
}
cork->length += length;
@@ -1207,6 +1215,15 @@ alloc_new_skb:
err = -EFAULT;
goto error;
}
+ } else if (flags & MSG_SPLICE_PAGES) {
+ struct msghdr *msg = from;
+
+ err = skb_splice_from_iter(skb, &msg->msg_iter, copy,
+ sk->sk_allocation);
+ if (err < 0)
+ goto error;
+ copy = err;
+ wmem_alloc_delta += copy;
} else if (!zc) {
int i = skb_shinfo(skb)->nr_frags;