Some block devices, like dm, bubble back -EAGAIN through the completion
handler. We cannot easily support the retry based buffered aio for those,
so catch it early and use the old style io-wq based fallback.
Fixes: bcf5a06304d6 ("io_uring: support true async buffered reads, if file provides it")
Reported-by: Zorro Lang <zlang@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
fs/io_uring.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 05670a615663..c9be9a607401 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3100,6 +3100,13 @@ static bool io_rw_should_retry(struct io_kiocb *req)
if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
return false;
+ /*
+ * If we can't do nonblock submit without -EAGAIN direct return,
+ * then don't use the retry based approach.
+ */
+ if (!io_file_supports_async(req->file, READ))
+ return false;
+
wait->wait.func = io_async_buf_func;
wait->wait.private = req;
wait->wait.flags = 0;
--
2.28.0
