From 48bdd849e967f1c573d2b2bc24308e24a83f39c2 Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Mon, 6 Apr 2020 00:08:52 +0300 Subject: [PATCH] io_uring: fix ctx refcounting in io_submit_sqes() If io_get_req() fails, it drops a ref. Then, awhile keeping @submitted unmodified, io_submit_sqes() breaks the loop and puts @nr - @submitted refs. For each submitted req a ref is dropped in io_put_req() and friends. So, for @nr taken refs there will be (@nr - @submitted + @submitted + 1) dropped. Remove ctx refcounting from io_get_req(), that at the same time makes it clearer. Fixes: 2b85edfc0c90 ("io_uring: batch getting pcpu references") Cc: stable@vger.kernel.org # v5.6 Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 78ae8e8ed5bf..79bd22289d73 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -1342,7 +1342,6 @@ fallback: req = io_get_fallback_req(ctx); if (req) goto got_it; - percpu_ref_put(&ctx->refs); return NULL; }