From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 12 Mar 2024 14:29:47 +0000 (-0600)
Subject: io_uring/rw: return IOU_ISSUE_SKIP_COMPLETE for multishot retry
X-Git-Tag: v6.8.3~244
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=1c3c480a2f686c1d74ea263ff06956af6899af5f;p=thirdparty%2Fkernel%2Fstable.git

io_uring/rw: return IOU_ISSUE_SKIP_COMPLETE for multishot retry

[ Upstream commit 0a3737db8479b77f95f4bfda8e71b03c697eb56a ]

If read multishot is being invoked from the poll retry handler, then we
should return IOU_ISSUE_SKIP_COMPLETE rather than -EAGAIN. If not, then
a CQE will be posted with -EAGAIN rather than triggering the retry when
the file is flagged as readable again.

Cc: stable@vger.kernel.org
Reported-by: Sargun Dhillon <sargun@meta.com>
Fixes: fc68fcda04910 ("io_uring/rw: add support for IORING_OP_READ_MULTISHOT")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/io_uring/rw.c b/io_uring/rw.c
index 8756e367acd91..2b84ce8a8a677 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -948,6 +948,8 @@ int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags)
 		 */
 		if (io_kbuf_recycle(req, issue_flags))
 			rw->len = 0;
+		if (issue_flags & IO_URING_F_MULTISHOT)
+			return IOU_ISSUE_SKIP_COMPLETE;
 		return -EAGAIN;
 	}