[PATCH 5.8 186/255] io_uring: clear req->result on IOPOLL re-issue

[Greg Kroah-Hartman]

From: Jens Axboe <axboe@xxxxxxxxx>

commit 56450c20fe10d4d93f58019109aa4e06fc0b9206 upstream.

Make sure we clear req->result, which was set to -EAGAIN for retry
purposes, when moving it to the reissue list. Otherwise we can end up
retrying a request more than once, which leads to weird results in
the io-wq handling (and other spots).

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Andres Freund <andres@xxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/io_uring.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1810,6 +1810,7 @@ static void io_iopoll_complete(struct io
 
 		req = list_first_entry(done, struct io_kiocb, list);
 		if (READ_ONCE(req->result) == -EAGAIN) {
+			req->result = 0;
 			req->iopoll_completed = 0;
 			list_move_tail(&req->list, &again);
 			continue;