[PATCH 5.15] io_uring: fix ltimeout unprep

[Pavel Begunkov <asml.silence@gmail.com>]

io_unprep_linked_timeout() is broken, first it needs to return back
REQ_F_ARM_LTIMEOUT, so the linked timeout is enqueued and disarmed. But
now we refcounted it, and linked timeouts may get not executed at all,
leaking a request.

Just kill the unprep optimisation.

Fixes: 906c6caaf5861 ("io_uring: optimise io_prep_linked_timeout()")
Reported-by: Beld Zhang <beldzhang@gmail.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c87931d8b503..18de14a9e7a4 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1406,11 +1406,6 @@ static inline void io_req_track_inflight(struct io_kiocb *req)
 	}
 }
 
-static inline void io_unprep_linked_timeout(struct io_kiocb *req)
-{
-	req->flags &= ~REQ_F_LINK_TIMEOUT;
-}
-
 static struct io_kiocb *__io_prep_linked_timeout(struct io_kiocb *req)
 {
 	if (WARN_ON_ONCE(!req->link))
@@ -6892,10 +6887,6 @@ static void io_queue_sqe_arm_apoll(struct io_kiocb *req)
 
 	switch (io_arm_poll_handler(req)) {
 	case IO_APOLL_READY:
-		if (linked_timeout) {
-			io_unprep_linked_timeout(req);
-			linked_timeout = NULL;
-		}
 		io_req_task_queue(req);
 		break;
 	case IO_APOLL_ABORTED:
-- 
2.33.1