io_uring: be consistent in assigning next work from handler

to #26323578

commit 78912934f4f7dd7a424159c69bf9bdd46e823781 upstream.

If we pass back dependent work in case of links, we need to always
ensure that we call the link setup and work prep handler. If not, we
might be missing some setup for the next work item.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Signed-off-by: NJoseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: NXiaoguang Wang <xiaoguang.wang@linux.alibaba.com>

fs/io_uring.c

@@ -2033,6 +2033,28 @@ static bool io_req_cancelled(struct io_kiocb *req)
 	return false;
 }
 
+static void io_link_work_cb(struct io_wq_work **workptr)
+{
+	struct io_wq_work *work = *workptr;
+	struct io_kiocb *link = work->data;
+
+	io_queue_linked_timeout(link);
+	work->func = io_wq_submit_work;
+}
+
+static void io_wq_assign_next(struct io_wq_work **workptr, struct io_kiocb *nxt)
+{
+	struct io_kiocb *link;
+
+	io_prep_async_work(nxt, &link);
+	*workptr = &nxt->work;
+	if (link) {
+		nxt->work.flags |= IO_WQ_WORK_CB;
+		nxt->work.func = io_link_work_cb;
+		nxt->work.data = link;
+	}
+}
+
 static void io_fsync_finish(struct io_wq_work **workptr)
 {
 	struct io_kiocb *req = container_of(*workptr, struct io_kiocb, work);
@@ -2051,7 +2073,7 @@ static void io_fsync_finish(struct io_wq_work **workptr)
 	io_cqring_add_event(req, ret);
 	io_put_req_find_next(req, &nxt);
 	if (nxt)
-		*workptr = &nxt->work;
+		io_wq_assign_next(workptr, nxt);
 }
 
 static int io_fsync(struct io_kiocb *req, struct io_kiocb **nxt,
@@ -2107,7 +2129,7 @@ static void io_sync_file_range_finish(struct io_wq_work **workptr)
 	io_cqring_add_event(req, ret);
 	io_put_req_find_next(req, &nxt);
 	if (nxt)
-		*workptr = &nxt->work;
+		io_wq_assign_next(workptr, nxt);
 }
 
 static int io_sync_file_range(struct io_kiocb *req, struct io_kiocb **nxt,
@@ -2373,7 +2395,7 @@ static void io_accept_finish(struct io_wq_work **workptr)
 		return;
 	__io_accept(req, &nxt, false);
 	if (nxt)
-		*workptr = &nxt->work;
+		io_wq_assign_next(workptr, nxt);
 }
 #endif
 
@@ -2604,7 +2626,7 @@ static void io_poll_complete_work(struct io_wq_work **workptr)
 		req_set_fail_links(req);
 	io_put_req_find_next(req, &nxt);
 	if (nxt)
-		*workptr = &nxt->work;
+		io_wq_assign_next(workptr, nxt);
 }
 
 static int io_poll_wake(struct wait_queue_entry *wait, unsigned mode, int sync,
@@ -3267,15 +3289,6 @@ static int io_issue_sqe(struct io_kiocb *req, const struct io_uring_sqe *sqe,
 	return 0;
 }
 
-static void io_link_work_cb(struct io_wq_work **workptr)
-{
-	struct io_wq_work *work = *workptr;
-	struct io_kiocb *link = work->data;
-
-	io_queue_linked_timeout(link);
-	work->func = io_wq_submit_work;
-}
-
 static void io_wq_submit_work(struct io_wq_work **workptr)
 {
 	struct io_wq_work *work = *workptr;
@@ -3312,17 +3325,8 @@ static void io_wq_submit_work(struct io_wq_work **workptr)
 	}
 
 	/* if a dependent link is ready, pass it back */
-	if (!ret && nxt) {
-		struct io_kiocb *link;
-
-		io_prep_async_work(nxt, &link);
-		*workptr = &nxt->work;
-		if (link) {
-			nxt->work.flags |= IO_WQ_WORK_CB;
-			nxt->work.func = io_link_work_cb;
-			nxt->work.data = link;
-		}
-	}
+	if (!ret && nxt)
+		io_wq_assign_next(workptr, nxt);
 }
 
 static bool io_req_op_valid(int op)