io_uring: don't attempt IO reissue from the ring exit path

[ Upstream commit 7c977a58dc83366e488c217fd88b1469d242bee5 ]

If we're exiting the ring, just let the IO fail with -EAGAIN as nobody
will care anyway. It's not the right context to reissue from.

Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 5746998799abcdc5c0b621c8a138d6b34d30f8ab..7625b3e2db2c9479b9128332d7f6c9b890eea426 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2617,6 +2617,13 @@ static bool io_rw_reissue(struct io_kiocb *req, long res)
                return false;
        if ((res != -EAGAIN && res != -EOPNOTSUPP) || io_wq_current_is_worker())
                return false;
+       /*
+        * If ref is dying, we might be running poll reap from the exit work.
+        * Don't attempt to reissue from that path, just let it fail with
+        * -EAGAIN.
+        */
+       if (percpu_ref_is_dying(&req->ctx->refs))
+               return false;
 
        ret = io_sq_thread_acquire_mm(req->ctx, req);