io_uring: make del_task_file more forgiving

Rework io_uring_del_task_file(), so it accepts an index to delete, and
it's not necessarily have to be in the ->xa. Infer file from xa_erase()
to maintain a single origin of truth.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -8785,14 +8785,17 @@ static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
 /*
  * Remove this io_uring_file -> task mapping.
  */
-static void io_uring_del_task_file(struct file *file)
+static void io_uring_del_task_file(unsigned long index)
 {
 	struct io_uring_task *tctx = current->io_uring;
+	struct file *file;
+
+	file = xa_erase(&tctx->xa, index);
+	if (!file)
+		return;
 
 	if (tctx->last == file)
 		tctx->last = NULL;
-	file = xa_erase(&tctx->xa, (unsigned long)file);
-	if (file)
 	fput(file);
 }
 
@@ -8802,7 +8805,7 @@ static void io_uring_clean_tctx(struct io_uring_task *tctx)
 	unsigned long index;
 
 	xa_for_each(&tctx->xa, index, file)
-		io_uring_del_task_file(file);
+		io_uring_del_task_file(index);
 	if (tctx->io_wq) {
 		io_wq_put_and_exit(tctx->io_wq);
 		tctx->io_wq = NULL;