The patch below does not apply to the 5.11-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to [off-list ref].
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From b5b0ecb736f1ce1e68eb50613c0cfecff10198eb Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Thu, 4 Mar 2021 21:02:58 -0700
Subject: [PATCH] io_uring: clear IOCB_WAITQ for non -EIOCBQUEUED return
The callback can only be armed, if we get -EIOCBQUEUED returned. It's
important that we clear the WAITQ bit for other cases, otherwise we can
queue for async retry and filemap will assume that we're armed and
return -EAGAIN instead of just blocking for the IO.
Cc: stable@vger.kernel.org # 5.9+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 044170165402..5762750c666c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3286,6 +3286,7 @@ static int io_read(struct io_kiocb *req, unsigned int issue_flags)
if (ret == -EIOCBQUEUED)
return 0;
/* we got some bytes, but not all. retry. */
+ kiocb->ki_flags &= ~IOCB_WAITQ;
} while (ret > 0 && ret < io_size);
done:
kiocb_done(kiocb, ret, issue_flags);