If the given protocol supports passing back whether or not we had more
pending accept post this one, pass back this information to userspace.
This is done by setting IORING_CQE_F_SOCK_NONEMPTY in the CQE flags,
just like we do for recv/recvmsg if there's more data available post
a receive operation.
We can also use this information to be smarter about multishot retry,
as we don't need to do a pointless retry if we know for a fact that
there aren't any more connections to accept.
Suggested-by: Norman Maurer <norman_maurer@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
io_uring/net.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/io_uring/net.c b/io_uring/net.c
index d4d1fc93635c..0a48596429d9 100644
--- a/io_uring/net.c
+++ b/io_uring/net.c
@@ -1533,6 +1533,7 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags)
.flags = force_nonblock ? O_NONBLOCK : 0,
};
struct file *file;
+ unsigned cflags;
int ret, fd;
if (!(req->flags & REQ_F_POLLED) &&
@@ -1545,6 +1546,8 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags)
if (unlikely(fd < 0))
return fd;
}
+ arg.err = 0;
+ arg.is_empty = -1;
file = do_accept(req->file, &arg, accept->addr, accept->addr_len,
accept->flags);
if (IS_ERR(file)) {
@@ -1573,17 +1576,26 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags)
accept->file_slot);
}
+ cflags = 0;
+ if (!arg.is_empty)
+ cflags |= IORING_CQE_F_SOCK_NONEMPTY;
+
if (!(req->flags & REQ_F_APOLL_MULTISHOT)) {
- io_req_set_res(req, ret, 0);
+ io_req_set_res(req, ret, cflags);
return IOU_OK;
}
if (ret < 0)
return ret;
- if (io_req_post_cqe(req, ret, IORING_CQE_F_MORE))
- goto retry;
+ if (io_req_post_cqe(req, ret, cflags | IORING_CQE_F_MORE)) {
+ if (cflags & IORING_CQE_F_SOCK_NONEMPTY || arg.is_empty == -1)
+ goto retry;
+ if (issue_flags & IO_URING_F_MULTISHOT)
+ return IOU_ISSUE_SKIP_COMPLETE;
+ return -EAGAIN;
+ }
- io_req_set_res(req, ret, 0);
+ io_req_set_res(req, ret, cflags);
return IOU_STOP_MULTISHOT;
}
--
2.43.0
