From: Jens Axboe <axboe@kernel.dk>
To: io-uring <io-uring@vger.kernel.org>
Subject: [PATCH] io_uring: treat -EAGAIN for REQ_F_NOWAIT as final for io-wq
Date: Thu, 20 Jul 2023 13:18:51 -0600 [thread overview]
Message-ID: <363d8e40-6acc-57bd-feb1-4dbd50e15c31@kernel.dk> (raw)
io-wq assumes that an issue is blocking, but it may not be if the
request type has asked for a non-blocking attempt. If we get
-EAGAIN for that case, then we need to treat it as a final result
and not retry or arm poll for it.
Cc: stable@vger.kernel.org # 5.10+
Link: https://github.com/axboe/liburing/issues/897
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index a9923676d16d..5e97235a82d6 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1948,6 +1948,14 @@ void io_wq_submit_work(struct io_wq_work *work)
ret = io_issue_sqe(req, issue_flags);
if (ret != -EAGAIN)
break;
+
+ /*
+ * If REQ_F_NOWAIT is set, then don't wait or retry with
+ * poll. -EAGAIN is final for that case.
+ */
+ if (req->flags & REQ_F_NOWAIT)
+ break;
+
/*
* We can get EAGAIN for iopolled IO even though we're
* forcing a sync submission from here, since we can't
--
Jens Axboe
reply other threads:[~2023-07-20 19:18 UTC|newest]
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