From 797f3f535d59f05ad12c629338beef6cb801d19e Mon Sep 17 00:00:00 2001
From: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Date: Wed, 15 Jan 2020 18:37:45 -0800
Subject: io_uring: clear req->result always before issuing a read/write
request
req->result is cleared when io_issue_sqe() calls io_read/write_pre()
routines. Those routines however are not called when the sqe
argument is NULL, which is the case when io_issue_sqe() is called from
io_wq_submit_work(). io_issue_sqe() may then examine a stale result if
a polled request had previously failed with -EAGAIN:
if (ctx->flags & IORING_SETUP_IOPOLL) {
if (req->result == -EAGAIN)
return -EAGAIN;
io_iopoll_req_issued(req);
}
and in turn cause a subsequently completed request to be re-issued in
io_wq_submit_work().
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 2 ++
1 file changed, 2 insertions(+)
(limited to 'fs')
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e32268ce38a5..3130ed16456e 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1843,6 +1843,7 @@ static int io_read(struct io_kiocb *req, struct io_kiocb **nxt,
if (!force_nonblock)
req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT;
+ req->result = 0;
io_size = ret;
if (req->flags & REQ_F_LINK)
req->result = io_size;
@@ -1930,6 +1931,7 @@ static int io_write(struct io_kiocb *req, struct io_kiocb **nxt,
if (!force_nonblock)
req->rw.kiocb.ki_flags &= ~IOCB_NOWAIT;
+ req->result = 0;
io_size = ret;
if (req->flags & REQ_F_LINK)
req->result = io_size;
--
cgit