io_uring/rsrc: fix DEFER_TASKRUN rsrc quiesce

For io_rsrc_ref_quiesce() to progress it should execute all task_work
items, including deferred ones. However, currently nobody would wake us,
and so let's set ctx->cq_wait_nr, so io_req_local_work_add() would wake
us up.

Fixes: c0e0d6b ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/f1a90d1bc5ebf096475b018fed52e54f3b89d4af.1681395792.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: isilence

io_uring/rsrc.c

@@ -273,6 +273,11 @@ __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
 	if (io_put_rsrc_data_ref(data))
 		return 0;
 
+	if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
+		atomic_set(&ctx->cq_wait_nr, 1);
+		smp_mb();
+	}
+
 	data->quiesce = true;
 	do {
 		prepare_to_wait(&ctx->rsrc_quiesce_wq, &we, TASK_INTERRUPTIBLE);
@@ -298,6 +303,10 @@ __cold static int io_rsrc_ref_quiesce(struct io_rsrc_data *data,
 
 	finish_wait(&ctx->rsrc_quiesce_wq, &we);
 	data->quiesce = false;
+	if (ctx->flags & IORING_SETUP_DEFER_TASKRUN) {
+		atomic_set(&ctx->cq_wait_nr, 0);
+		smp_mb();
+	}
 	return ret;
 }