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| author | David Howells <dhowells@redhat.com> | 2023-05-22 13:11:24 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-05-23 20:48:27 -0700 |
| commit | a0dbf5f818f9082d2262c1f8a8c0aab68364341f (patch) | |
| tree | 85424257b8c06171fe29c981450b81a75dbc6417 /net/unix | |
| parent | c49cf26632910581ee1173d75c0fca322ccaf4bb (diff) | |
| download | lwn-a0dbf5f818f9082d2262c1f8a8c0aab68364341f.tar.gz lwn-a0dbf5f818f9082d2262c1f8a8c0aab68364341f.zip | |
af_unix: Support MSG_SPLICE_PAGES
Make AF_UNIX sendmsg() support MSG_SPLICE_PAGES, splicing in pages from the
source iterator if possible and copying the data in otherwise.
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: Kuniyuki Iwashima <kuniyu@amazon.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/unix')
| -rw-r--r-- | net/unix/af_unix.c | 49 |
1 files changed, 33 insertions, 16 deletions
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index dd55506b4632..976bc1c5e11b 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -2200,19 +2200,25 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, while (sent < len) { size = len - sent; - /* Keep two messages in the pipe so it schedules better */ - size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); + if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) { + skb = sock_alloc_send_pskb(sk, 0, 0, + msg->msg_flags & MSG_DONTWAIT, + &err, 0); + } else { + /* Keep two messages in the pipe so it schedules better */ + size = min_t(int, size, (sk->sk_sndbuf >> 1) - 64); - /* allow fallback to order-0 allocations */ - size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); + /* allow fallback to order-0 allocations */ + size = min_t(int, size, SKB_MAX_HEAD(0) + UNIX_SKB_FRAGS_SZ); - data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); + data_len = max_t(int, 0, size - SKB_MAX_HEAD(0)); - data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); + data_len = min_t(size_t, size, PAGE_ALIGN(data_len)); - skb = sock_alloc_send_pskb(sk, size - data_len, data_len, - msg->msg_flags & MSG_DONTWAIT, &err, - get_order(UNIX_SKB_FRAGS_SZ)); + skb = sock_alloc_send_pskb(sk, size - data_len, data_len, + msg->msg_flags & MSG_DONTWAIT, &err, + get_order(UNIX_SKB_FRAGS_SZ)); + } if (!skb) goto out_err; @@ -2224,13 +2230,24 @@ static int unix_stream_sendmsg(struct socket *sock, struct msghdr *msg, } fds_sent = true; - skb_put(skb, size - data_len); - skb->data_len = data_len; - skb->len = size; - err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); - if (err) { - kfree_skb(skb); - goto out_err; + if (unlikely(msg->msg_flags & MSG_SPLICE_PAGES)) { + err = skb_splice_from_iter(skb, &msg->msg_iter, size, + sk->sk_allocation); + if (err < 0) { + kfree_skb(skb); + goto out_err; + } + size = err; + refcount_add(size, &sk->sk_wmem_alloc); + } else { + skb_put(skb, size - data_len); + skb->data_len = data_len; + skb->len = size; + err = skb_copy_datagram_from_iter(skb, 0, &msg->msg_iter, size); + if (err) { + kfree_skb(skb); + goto out_err; + } } unix_state_lock(other); |