io_uring: do post-completion chore on t-out cancel

Don't forget about io_commit_cqring() + io_cqring_ev_posted() after
exit/exec cancelling timeouts. Both functions declared only after
io_kill_timeouts(), so to avoid tons of forward declarations move
it down.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/72ace588772c0f14834a6a4185d56c445a366fb4.1616696997.git.asml.silence@gmail.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -1262,26 +1262,6 @@ static void io_kill_timeout(struct io_kiocb *req, int status)
 	}
 }
 
-/*
- * Returns true if we found and killed one or more timeouts
- */
-static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
-			     struct files_struct *files)
-{
-	struct io_kiocb *req, *tmp;
-	int canceled = 0;
-
-	spin_lock_irq(&ctx->completion_lock);
-	list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
-		if (io_match_task(req, tsk, files)) {
-			io_kill_timeout(req, -ECANCELED);
-			canceled++;
-		}
-	}
-	spin_unlock_irq(&ctx->completion_lock);
-	return canceled != 0;
-}
-
 static void __io_queue_deferred(struct io_ring_ctx *ctx)
 {
 	do {
@@ -8611,6 +8591,28 @@ static void io_ring_exit_work(struct work_struct *work)
 	io_ring_ctx_free(ctx);
 }
 
+/* Returns true if we found and killed one or more timeouts */
+static bool io_kill_timeouts(struct io_ring_ctx *ctx, struct task_struct *tsk,
+			     struct files_struct *files)
+{
+	struct io_kiocb *req, *tmp;
+	int canceled = 0;
+
+	spin_lock_irq(&ctx->completion_lock);
+	list_for_each_entry_safe(req, tmp, &ctx->timeout_list, timeout.list) {
+		if (io_match_task(req, tsk, files)) {
+			io_kill_timeout(req, -ECANCELED);
+			canceled++;
+		}
+	}
+	io_commit_cqring(ctx);
+	spin_unlock_irq(&ctx->completion_lock);
+
+	if (canceled != 0)
+		io_cqring_ev_posted(ctx);
+	return canceled != 0;
+}
+
 static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
 {
 	unsigned long index;