[PATCH 13/20] io_uring/zcrx: propagate ifq down the stack

[David Wei <dw@davidwei.uk>]

From: Pavel Begunkov <asml.silence@gmail.com>

We need to know the current ifq for copy fallback purposes, so pass it
down from the issue callback down to zc_rx_recv_frag(). It'll also be
needed in the future for notifications, accounting and so on.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Wei <dw@davidwei.uk>
---
 io_uring/net.c   |  2 +-
 io_uring/zc_rx.c | 30 +++++++++++++++++++-----------
 io_uring/zc_rx.h |  3 ++-
 3 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/io_uring/net.c b/io_uring/net.c
index 79f2ed3a6fc0..e7b41c5826d5 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1053,7 +1053,7 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
 	if (flags & MSG_WAITALL)
 		min_ret = zc->len;
 
-	ret = io_zc_rx_recv(sock, zc->datalen, flags);
+	ret = io_zc_rx_recv(ifq, sock, zc->datalen, flags);
 	if (ret < min_ret) {
 		if (ret == -EAGAIN && force_nonblock) {
 			if (issue_flags & IO_URING_F_MULTISHOT)
diff --git a/io_uring/zc_rx.c b/io_uring/zc_rx.c
index 842aae760deb..038692d3265e 100644
--- a/io_uring/zc_rx.c
+++ b/io_uring/zc_rx.c
@@ -577,7 +577,7 @@ static struct io_zc_rx_ifq *io_zc_rx_ifq_skb(struct sk_buff *skb)
 }
 
 static int zc_rx_recv_frag(struct io_zc_rx_ifq *ifq, const skb_frag_t *frag,
-			   int off, int len)
+			   int off, int len, bool zc_skb)
 {
 	struct io_uring_rbuf_cqe *cqe;
 	unsigned int cq_idx, queued, free, entries;
@@ -588,7 +588,7 @@ static int zc_rx_recv_frag(struct io_zc_rx_ifq *ifq, const skb_frag_t *frag,
 	page = skb_frag_page(frag);
 	off += skb_frag_off(frag);
 
-	if (likely(ifq && is_zc_rx_page(page))) {
+	if (likely(zc_skb && is_zc_rx_page(page))) {
 		mask = ifq->cq_entries - 1;
 		pgid = page_private(page) & 0xffffffff;
 		io_zc_rx_get_buf_uref(ifq->pool, pgid);
@@ -618,14 +618,19 @@ static int
 zc_rx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
 	       unsigned int offset, size_t len)
 {
-	struct io_zc_rx_ifq *ifq;
+	struct io_zc_rx_ifq *ifq = desc->arg.data;
+	struct io_zc_rx_ifq *skb_ifq;
 	struct sk_buff *frag_iter;
 	unsigned start, start_off;
 	int i, copy, end, off;
+	bool zc_skb = true;
 	int ret = 0;
 
-	ifq = io_zc_rx_ifq_skb(skb);
-	if (!ifq) {
+	skb_ifq = io_zc_rx_ifq_skb(skb);
+	if (unlikely(ifq != skb_ifq)) {
+		zc_skb = false;
+		if (WARN_ON_ONCE(skb_ifq))
+			return -EFAULT;
 		pr_debug("non zerocopy pages are not supported\n");
 		return -EFAULT;
 	}
@@ -649,7 +654,7 @@ zc_rx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
 				copy = len;
 
 			off = offset - start;
-			ret = zc_rx_recv_frag(ifq, frag, off, copy);
+			ret = zc_rx_recv_frag(ifq, frag, off, copy, zc_skb);
 			if (ret < 0)
 				goto out;
 
@@ -690,16 +695,18 @@ zc_rx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
 	return offset - start_off;
 }
 
-static int io_zc_rx_tcp_read(struct sock *sk)
+static int io_zc_rx_tcp_read(struct io_zc_rx_ifq *ifq, struct sock *sk)
 {
 	read_descriptor_t rd_desc = {
 		.count = 1,
+		.arg.data = ifq,
 	};
 
 	return tcp_read_sock(sk, &rd_desc, zc_rx_recv_skb);
 }
 
-static int io_zc_rx_tcp_recvmsg(struct sock *sk, unsigned int recv_limit,
+static int io_zc_rx_tcp_recvmsg(struct io_zc_rx_ifq *ifq, struct sock *sk,
+				unsigned int recv_limit,
 				int flags, int *addr_len)
 {
 	size_t used;
@@ -712,7 +719,7 @@ static int io_zc_rx_tcp_recvmsg(struct sock *sk, unsigned int recv_limit,
 
 	timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 	while (recv_limit) {
-		ret = io_zc_rx_tcp_read(sk);
+		ret = io_zc_rx_tcp_read(ifq, sk);
 		if (ret < 0)
 			break;
 		if (!ret) {
@@ -767,7 +774,8 @@ static int io_zc_rx_tcp_recvmsg(struct sock *sk, unsigned int recv_limit,
 	return ret;
 }
 
-int io_zc_rx_recv(struct socket *sock, unsigned int limit, unsigned int flags)
+int io_zc_rx_recv(struct io_zc_rx_ifq *ifq, struct socket *sock,
+		  unsigned int limit, unsigned int flags)
 {
 	struct sock *sk = sock->sk;
 	const struct proto *prot;
@@ -783,7 +791,7 @@ int io_zc_rx_recv(struct socket *sock, unsigned int limit, unsigned int flags)
 
 	sock_rps_record_flow(sk);
 
-	ret = io_zc_rx_tcp_recvmsg(sk, limit, flags, &addr_len);
+	ret = io_zc_rx_tcp_recvmsg(ifq, sk, limit, flags, &addr_len);
 
 	return ret;
 }
diff --git a/io_uring/zc_rx.h b/io_uring/zc_rx.h
index bfba21c370b0..fac32089e699 100644
--- a/io_uring/zc_rx.h
+++ b/io_uring/zc_rx.h
@@ -62,6 +62,7 @@ static inline int io_register_zc_rx_sock(struct io_ring_ctx *ctx,
 
 int io_recvzc(struct io_kiocb *req, unsigned int issue_flags);
 int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe);
-int io_zc_rx_recv(struct socket *sock, unsigned int limit, unsigned int flags);
+int io_zc_rx_recv(struct io_zc_rx_ifq *ifq, struct socket *sock,
+		  unsigned int limit, unsigned int flags);
 
 #endif
-- 
2.39.3