Merge tag 'for-6.2/io_uring-next-2022-12-08' of git://git.kernel.dk/linux

Pull io_uring updates part two from Jens Axboe:

 - Misc fixes (me, Lin)

 - Series from Pavel extending the single task exclusive ring mode,
   yielding nice improvements for the common case of having a single
   ring per thread (Pavel)

 - Cleanup for MSG_RING, removing our IOPOLL hack (Pavel)

 - Further poll cleanups and fixes (Pavel)

 - Misc cleanups and fixes (Pavel)

* tag 'for-6.2/io_uring-next-2022-12-08' of git://git.kernel.dk/linux: (22 commits)
  io_uring/msg_ring: flag target ring as having task_work, if needed
  io_uring: skip spinlocking for ->task_complete
  io_uring: do msg_ring in target task via tw
  io_uring: extract a io_msg_install_complete helper
  io_uring: get rid of double locking
  io_uring: never run tw and fallback in parallel
  io_uring: use tw for putting rsrc
  io_uring: force multishot CQEs into task context
  io_uring: complete all requests in task context
  io_uring: don't check overflow flush failures
  io_uring: skip overflow CQE posting for dying ring
  io_uring: improve io_double_lock_ctx fail handling
  io_uring: dont remove file from msg_ring reqs
  io_uring: reshuffle issue_flags
  io_uring: don't reinstall quiesce node for each tw
  io_uring: improve rsrc quiesce refs checks
  io_uring: don't raw spin unlock to match cq_lock
  io_uring: combine poll tw handlers
  io_uring: improve poll warning handling
  io_uring: remove ctx variable in io_poll_check_events
  ...

1 files changed, 21 insertions, 0 deletions

diff --git a/io_uring/net.c b/io_uring/net.c
index cb831326ea5b7..5229976cb5829 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);