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 8756e367acd91cf1685ef17c1355c37448376966..2b84ce8a8a677619108c09e1358dd382bd5bc204 100644 (file)
--- 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;
        }