From 17add5cea2bbafea0d481f1a3ea9dea019a98ee9 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Wed, 7 Dec 2022 03:53:31 +0000 Subject: io_uring: force multishot CQEs into task context Multishot are posting CQEs outside of the normal request completion path, which is usually done from within a task work handler. However, it might be not the case when it's yet to be polled but has been punted to io-wq. Make it abide ->task_complete and push it to the polling path when executed by io-wq. Signed-off-by: Pavel Begunkov Link: https://lore.kernel.org/r/d7714aaff583096769a0f26e8e747759e556feb1.1670384893.git.asml.silence@gmail.com Signed-off-by: Jens Axboe --- io_uring/net.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'io_uring') diff --git a/io_uring/net.c b/io_uring/net.c index 90342dcb6b1d..f276f6dd5b09 100644 --- a/io_uring/net.c +++ b/io_uring/net.c @@ -67,6 +67,19 @@ struct io_sr_msg { struct io_kiocb *notif; }; +static inline bool io_check_multishot(struct io_kiocb *req, + unsigned int issue_flags) +{ + /* + * When ->locked_cq is set we only allow to post CQEs from the original + * task context. Usual request completions will be handled in other + * generic paths but multipoll may decide to post extra cqes. + */ + return !(issue_flags & IO_URING_F_IOWQ) || + !(issue_flags & IO_URING_F_MULTISHOT) || + !req->ctx->task_complete; +} + int io_shutdown_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { struct io_shutdown *shutdown = io_kiocb_to_cmd(req, struct io_shutdown); @@ -730,6 +743,9 @@ int io_recvmsg(struct io_kiocb *req, unsigned int issue_flags) (sr->flags & IORING_RECVSEND_POLL_FIRST)) return io_setup_async_msg(req, kmsg, issue_flags); + if (!io_check_multishot(req, issue_flags)) + return io_setup_async_msg(req, kmsg, issue_flags); + retry_multishot: if (io_do_buffer_select(req)) { void __user *buf; @@ -829,6 +845,9 @@ int io_recv(struct io_kiocb *req, unsigned int issue_flags) (sr->flags & IORING_RECVSEND_POLL_FIRST)) return -EAGAIN; + if (!io_check_multishot(req, issue_flags)) + return -EAGAIN; + sock = sock_from_file(req->file); if (unlikely(!sock)) return -ENOTSOCK; @@ -1280,6 +1299,8 @@ int io_accept(struct io_kiocb *req, unsigned int issue_flags) struct file *file; int ret, fd; + if (!io_check_multishot(req, issue_flags)) + return -EAGAIN; retry: if (!fixed) { fd = __get_unused_fd_flags(accept->flags, accept->nofile); -- cgit v1.2.3