linux-kernel - [PATCH] io-wq: use put instead of revert creds

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Message-Id: <c79bab7a6bd174f32121c9508390264bff9950ca.1580292613.git.asml.silence@gmail.com>
Date:   Wed, 29 Jan 2020 13:10:23 +0300
From:   Pavel Begunkov <asml.silence@...il.com>
To:     Jens Axboe <axboe@...nel.dk>, io-uring@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH] io-wq: use put instead of revert creds

There is no need to publish creds twice in io_wq_switch_creds() (in
revert_creds() and override_creds()). Just do override_creds() and
put_creds() if needed.

Signed-off-by: Pavel Begunkov <asml.silence@...il.com>
---
 fs/io-wq.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/fs/io-wq.c b/fs/io-wq.c
index 8fbbadf04cc3..f7eb577ccd2d 100644
--- a/fs/io-wq.c
+++ b/fs/io-wq.c
@@ -425,11 +425,13 @@ static void io_wq_switch_mm(struct io_worker *worker, struct io_wq_work *work)
 static void io_wq_switch_creds(struct io_worker *worker,
 			       struct io_wq_work *work)
 {
-	if (worker->saved_creds)
-		revert_creds(worker->saved_creds);
+	const struct cred *old_creds = override_creds(work->creds);
 
-	worker->saved_creds = override_creds(work->creds);
 	worker->cur_creds = work->creds;
+	if (worker->saved_creds)
+		put_cred(old_creds); /* creds set by previous switch */
+	else
+		worker->saved_creds = old_creds;
 }
 
 static void io_worker_handle_work(struct io_worker *worker)
-- 
2.24.0