io_uring: fix skipping disabling sqo on exec

[ Upstream commit 0b5cd6c32b14413bf87e10ee62be3162588dcbe6 ]

If there are no requests at the time __io_uring_task_cancel() is called,
tctx_inflight() returns zero and and it terminates not getting a chance
to go through __io_uring_files_cancel() and do
io_disable_sqo_submit(). And we absolutely want them disabled by the
time cancellation ends.

Cc: stable@vger.kernel.org # 5.5+
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Fixes: d9d05217cb69 ("io_uring: stop SQPOLL submit on creator's death")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 02788fd..5018d49 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8917,6 +8917,10 @@ void __io_uring_task_cancel(void)
        /* make sure overflow events are dropped */
        atomic_inc(&tctx->in_idle);
 
+       /* trigger io_disable_sqo_submit() */
+       if (tctx->sqpoll)
+               __io_uring_files_cancel(NULL);
+
        do {
                /* read completions before cancelations */
                inflight = tctx_inflight(tctx);