在 2021/9/5 上午6:43, Pavel Begunkov 写道:
On 9/3/21 12:00 PM, Hao Xu wrote:
Update io_accept_prep() to enable multishot mode for accept operation.
Signed-off-by: Hao Xu <haoxu@xxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index eb81d37dce78..34612646ae3c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4861,6 +4861,7 @@ static int io_recv(struct io_kiocb *req, unsigned int issue_flags)
static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
struct io_accept *accept = &req->accept;
+ bool is_multishot;
if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
return -EINVAL;
@@ -4872,14 +4873,23 @@ static int io_accept_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
accept->flags = READ_ONCE(sqe->accept_flags);
accept->nofile = rlimit(RLIMIT_NOFILE);
+ is_multishot = accept->flags & IORING_ACCEPT_MULTISHOT;
+ if (is_multishot && (req->flags & REQ_F_FORCE_ASYNC))
+ return -EINVAL;
Why REQ_F_FORCE_ASYNC is not allowed? It doesn't sound like there
should be any problem, would just eventually go looping
poll_wait + tw
Hmm..The arm_poll facility is only on the io_submit_sqes() path. If
FORCE_ASYNC is set, the req goes to io_wq_submit_work-->io_issue_sqe.
Moreover, I guess theoretically poll based retry and async iowq are
two ways for users to handle their sqes, it may not be sane to go to
poll based retry path if a user already forcely choose iowq as their
prefer way.
+
accept->file_slot = READ_ONCE(sqe->file_index);
if (accept->file_slot && ((req->open.how.flags & O_CLOEXEC) ||
- (accept->flags & SOCK_CLOEXEC)))
+ (accept->flags & SOCK_CLOEXEC) || is_multishot))
return -EINVAL;
- if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK))
+ if (accept->flags & ~(SOCK_CLOEXEC | SOCK_NONBLOCK | IORING_ACCEPT_MULTISHOT))
return -EINVAL;
if (SOCK_NONBLOCK != O_NONBLOCK && (accept->flags & SOCK_NONBLOCK))
accept->flags = (accept->flags & ~SOCK_NONBLOCK) | O_NONBLOCK;
+ if (is_multishot) {
+ req->flags |= REQ_F_APOLL_MULTISHOT;
+ accept->flags &= ~IORING_ACCEPT_MULTISHOT;
+ }
+
return 0;
}
