1 files changed, 83 insertions, 15 deletions

diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 2f73f83af960..50bc3af44953 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -17,16 +17,18 @@ enum {
 	IOU_ISSUE_SKIP_COMPLETE	= -EIOCBQUEUED,
 
 	/*
-	 * Intended only when both REQ_F_POLLED and REQ_F_APOLL_MULTISHOT
-	 * are set to indicate to the poll runner that multishot should be
+	 * Intended only when both IO_URING_F_MULTISHOT is passed
+	 * to indicate to the poll runner that multishot should be
 	 * removed and the result is set on req->cqe.res.
 	 */
 	IOU_STOP_MULTISHOT	= -ECANCELED,
 };
 
-struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx);
+struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx, bool overflow);
 bool io_req_cqe_overflow(struct io_kiocb *req);
-int io_run_task_work_sig(void);
+int io_run_task_work_sig(struct io_ring_ctx *ctx);
+int __io_run_local_work(struct io_ring_ctx *ctx, bool *locked);
+int io_run_local_work(struct io_ring_ctx *ctx);
 void io_req_complete_failed(struct io_kiocb *req, s32 res);
 void __io_req_complete(struct io_kiocb *req, unsigned issue_flags);
 void io_req_complete_post(struct io_kiocb *req);
@@ -91,7 +93,8 @@ static inline void io_cq_lock(struct io_ring_ctx *ctx)
 
 void io_cq_unlock_post(struct io_ring_ctx *ctx);
 
-static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
+static inline struct io_uring_cqe *io_get_cqe_overflow(struct io_ring_ctx *ctx,
+						       bool overflow)
 {
 	if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
 		struct io_uring_cqe *cqe = ctx->cqe_cached;
@@ -103,7 +106,12 @@ static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
 		return cqe;
 	}
 
-	return __io_get_cqe(ctx);
+	return __io_get_cqe(ctx, overflow);
+}
+
+static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
+{
+	return io_get_cqe_overflow(ctx, false);
 }
 
 static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
@@ -195,17 +203,24 @@ static inline void io_commit_cqring(struct io_ring_ctx *ctx)
 	smp_store_release(&ctx->rings->cq.tail, ctx->cached_cq_tail);
 }
 
-static inline void io_cqring_wake(struct io_ring_ctx *ctx)
+/* requires smb_mb() prior, see wq_has_sleeper() */
+static inline void __io_cqring_wake(struct io_ring_ctx *ctx)
 {
 	/*
 	 * wake_up_all() may seem excessive, but io_wake_function() and
 	 * io_should_wake() handle the termination of the loop and only
 	 * wake as many waiters as we need to.
 	 */
-	if (wq_has_sleeper(&ctx->cq_wait))
+	if (waitqueue_active(&ctx->cq_wait))
 		wake_up_all(&ctx->cq_wait);
 }
 
+static inline void io_cqring_wake(struct io_ring_ctx *ctx)
+{
+	smp_mb();
+	__io_cqring_wake(ctx);
+}
+
 static inline bool io_sqring_full(struct io_ring_ctx *ctx)
 {
 	struct io_rings *r = ctx->rings;
@@ -221,17 +236,64 @@ static inline unsigned int io_sqring_entries(struct io_ring_ctx *ctx)
 	return smp_load_acquire(&rings->sq.tail) - ctx->cached_sq_head;
 }
 
-static inline bool io_run_task_work(void)
+static inline int io_run_task_work(void)
 {
-	if (test_thread_flag(TIF_NOTIFY_SIGNAL)) {
-		__set_current_state(TASK_RUNNING);
+	/*
+	 * Always check-and-clear the task_work notification signal. With how
+	 * signaling works for task_work, we can find it set with nothing to
+	 * run. We need to clear it for that case, like get_signal() does.
+	 */
+	if (test_thread_flag(TIF_NOTIFY_SIGNAL))
 		clear_notify_signal();
-		if (task_work_pending(current))
-			task_work_run();
-		return true;
+	if (task_work_pending(current)) {
+		__set_current_state(TASK_RUNNING);
+		task_work_run();
+		return 1;
 	}
 
-	return false;
+	return 0;
+}
+
+static inline bool io_task_work_pending(struct io_ring_ctx *ctx)
+{
+	return test_thread_flag(TIF_NOTIFY_SIGNAL) ||
+		!wq_list_empty(&ctx->work_llist);
+}
+
+static inline int io_run_task_work_ctx(struct io_ring_ctx *ctx)
+{
+	int ret = 0;
+	int ret2;
+
+	if (ctx->flags & IORING_SETUP_DEFER_TASKRUN)
+		ret = io_run_local_work(ctx);
+
+	/* want to run this after in case more is added */
+	ret2 = io_run_task_work();
+
+	/* Try propagate error in favour of if tasks were run,
+	 * but still make sure to run them if requested
+	 */
+	if (ret >= 0)
+		ret += ret2;
+
+	return ret;
+}
+
+static inline int io_run_local_work_locked(struct io_ring_ctx *ctx)
+{
+	bool locked;
+	int ret;
+
+	if (llist_empty(&ctx->work_llist))
+		return 0;
+
+	locked = true;
+	ret = __io_run_local_work(ctx, &locked);
+	/* shouldn't happen! */
+	if (WARN_ON_ONCE(!locked))
+		mutex_lock(&ctx->uring_lock);
+	return ret;
 }
 
 static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
@@ -301,4 +363,10 @@ static inline struct io_kiocb *io_alloc_req(struct io_ring_ctx *ctx)
 	return container_of(node, struct io_kiocb, comp_list);
 }
 
+static inline bool io_allowed_run_tw(struct io_ring_ctx *ctx)
+{
+	return likely(!(ctx->flags & IORING_SETUP_DEFER_TASKRUN) ||
+		      ctx->submitter_task == current);
+}
+
 #endif