On 2/24/25 04:13, David Wei wrote:
Currently multishot recvzc requests have no read limit and will remain
active so as long as the socket remains open. But, there are sometimes a
need to do a fixed length read e.g. peeking at some data in the socket.
Add a length limit to recvzc requests `len`. A value of 0 means no limit
which is the previous behaviour. A positive value N specifies how many
bytes to read from the socket.
Data will still be posted in aux completions, as before. This could be
split across multiple frags. But the primary recvzc request will now
complete once N bytes have been read. The completion of the recvzc
request will have res and cflags both set to 0.
Looks fine, can be improved later.
Reviewed-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: David Wei <dw@xxxxxxxxxxx>
---
io_uring/net.c | 16 +++++++++++++---
io_uring/zcrx.c | 13 +++++++++----
io_uring/zcrx.h | 2 +-
3 files changed, 23 insertions(+), 8 deletions(-)
...
diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index f2d326e18e67..9c95b5b6ec4e 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,
...
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;
struct io_zcrx_args args = {
.req = req,
.ifq = ifq,
.sock = sk->sk_socket,
};
read_descriptor_t rd_desc = {
- .count = 1,
+ .count = len ? len : UINT_MAX,
typedef struct {
...
size_t count;
} read_descriptor_t;
Should be SIZE_MAX, but it's not worth of respinning.
--
Pavel Begunkov
