On 2025-02-24 05:11, Pavel Begunkov wrote:
> 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.
I'll send a follow up.
>
