Currently only multishot recvzc requests are supported, but sometimes
there is a need to do a single recv e.g. peeking at some data in the
socket. Add single shot recvzc requests where IORING_RECV_MULTISHOT is
_not_ set and the sqe->len field is set to the number of bytes to read
N.
There could be multiple completions containing data, like the multishot
case, since N bytes could be split across multiple frags. This is
followed by a final completion with res and cflags both set to 0 that
indicate the completion of the request, or a -res that indicate an
error.
Signed-off-by: David Wei <dw@xxxxxxxxxxx>
---
io_uring/net.c | 19 +++++++++++++++++--
io_uring/zcrx.c | 17 ++++++++++++-----
io_uring/zcrx.h | 2 +-
3 files changed, 30 insertions(+), 8 deletions(-)
diff --git a/io_uring/net.c b/io_uring/net.c
index 000dc70d08d0..cae34a24266c 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -94,6 +94,7 @@ struct io_recvzc {
struct file *file;
unsigned msg_flags;
u16 flags;
+ u32 len;
struct io_zcrx_ifq *ifq;
};
@@ -1241,7 +1242,7 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
unsigned ifq_idx;
if (unlikely(sqe->file_index || sqe->addr2 || sqe->addr ||
- sqe->len || sqe->addr3))
+ sqe->addr3))
return -EINVAL;
ifq_idx = READ_ONCE(sqe->zcrx_ifq_idx);
@@ -1250,6 +1251,12 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
zc->ifq = req->ctx->ifq;
if (!zc->ifq)
return -EINVAL;
+ zc->len = READ_ONCE(sqe->len);
+ if (zc->len == UINT_MAX)
+ return -EINVAL;
+ /* UINT_MAX means no limit on readlen */
+ if (!zc->len)
+ zc->len = UINT_MAX;
zc->flags = READ_ONCE(sqe->ioprio);
zc->msg_flags = READ_ONCE(sqe->msg_flags);
@@ -1269,6 +1276,7 @@ int io_recvzc_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
{
struct io_recvzc *zc = io_kiocb_to_cmd(req, struct io_recvzc);
+ bool limit = zc->len != UINT_MAX;
struct socket *sock;
int ret;
@@ -1281,7 +1289,7 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
return -ENOTSOCK;
ret = io_zcrx_recv(req, zc->ifq, sock, zc->msg_flags | MSG_DONTWAIT,
- issue_flags);
+ issue_flags, &zc->len);
if (unlikely(ret <= 0) && ret != -EAGAIN) {
if (ret == -ERESTARTSYS)
ret = -EINTR;
@@ -1296,6 +1304,13 @@ int io_recvzc(struct io_kiocb *req, unsigned int issue_flags)
return IOU_OK;
}
+ if (zc->len == 0) {
+ io_req_set_res(req, 0, 0);
+
+ if (issue_flags & IO_URING_F_MULTISHOT)
+ return IOU_STOP_MULTISHOT;
+ return IOU_OK;
+ }
if (issue_flags & IO_URING_F_MULTISHOT)
return IOU_ISSUE_SKIP_COMPLETE;
return -EAGAIN;
diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index f2d326e18e67..74bca4e471bc 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -817,6 +817,7 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
int i, copy, end, off;
int ret = 0;
+ len = min_t(size_t, len, desc->count);
if (unlikely(args->nr_skbs++ > IO_SKBS_PER_CALL_LIMIT))
return -EAGAIN;
@@ -894,26 +895,32 @@ io_zcrx_recv_skb(read_descriptor_t *desc, struct sk_buff *skb,
out:
if (offset == start_off)
return ret;
+ if (desc->count != UINT_MAX)
+ desc->count -= (offset - start_off);
return offset - start_off;
}
static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
struct sock *sk, int flags,
- unsigned issue_flags)
+ unsigned issue_flags, unsigned int *outlen)
{
+ unsigned int len = *outlen;
+ bool limit = len != UINT_MAX;
struct io_zcrx_args args = {
.req = req,
.ifq = ifq,
.sock = sk->sk_socket,
};
read_descriptor_t rd_desc = {
- .count = 1,
+ .count = len,
.arg.data = &args,
};
int ret;
lock_sock(sk);
ret = tcp_read_sock(sk, &rd_desc, io_zcrx_recv_skb);
+ if (limit && ret)
+ *outlen = len - ret;
if (ret <= 0) {
if (ret < 0 || sock_flag(sk, SOCK_DONE))
goto out;
@@ -930,7 +937,7 @@ static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
ret = IOU_REQUEUE;
} else if (sock_flag(sk, SOCK_DONE)) {
/* Make it to retry until it finally gets 0. */
- if (issue_flags & IO_URING_F_MULTISHOT)
+ if (!limit && (issue_flags & IO_URING_F_MULTISHOT))
ret = IOU_REQUEUE;
else
ret = -EAGAIN;
@@ -942,7 +949,7 @@ static int io_zcrx_tcp_recvmsg(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
struct socket *sock, unsigned int flags,
- unsigned issue_flags)
+ unsigned issue_flags, unsigned int *len)
{
struct sock *sk = sock->sk;
const struct proto *prot = READ_ONCE(sk->sk_prot);
@@ -951,5 +958,5 @@ int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
return -EPROTONOSUPPORT;
sock_rps_record_flow(sk);
- return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags);
+ return io_zcrx_tcp_recvmsg(req, ifq, sk, flags, issue_flags, len);
}
diff --git a/io_uring/zcrx.h b/io_uring/zcrx.h
index a16bdd921f03..1b4042dc48e2 100644
--- a/io_uring/zcrx.h
+++ b/io_uring/zcrx.h
@@ -46,7 +46,7 @@ void io_unregister_zcrx_ifqs(struct io_ring_ctx *ctx);
void io_shutdown_zcrx_ifqs(struct io_ring_ctx *ctx);
int io_zcrx_recv(struct io_kiocb *req, struct io_zcrx_ifq *ifq,
struct socket *sock, unsigned int flags,
- unsigned issue_flags);
+ unsigned issue_flags, unsigned int *len);
#else
static inline int io_register_zcrx_ifq(struct io_ring_ctx *ctx,
struct io_uring_zcrx_ifq_reg __user *arg)
--
2.43.5
