| From 6d6f67a74f7443635b1904b3955cc61ab3f1ea95 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 1 May 2020 17:09:37 +0300 |
| Subject: io_uring: check non-sync defer_list carefully |
| |
| From: Pavel Begunkov <asml.silence@gmail.com> |
| |
| [ Upstream commit 4ee3631451c9a62e6b6bc7ee51fb9a5b34e33509 ] |
| |
| io_req_defer() do double-checked locking. Use proper helpers for that, |
| i.e. list_empty_careful(). |
| |
| Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> |
| Signed-off-by: Jens Axboe <axboe@kernel.dk> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| fs/io_uring.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/fs/io_uring.c b/fs/io_uring.c |
| index 01f71b9efb88f..832e042531bc4 100644 |
| --- a/fs/io_uring.c |
| +++ b/fs/io_uring.c |
| @@ -4258,7 +4258,7 @@ static int io_req_defer(struct io_kiocb *req, const struct io_uring_sqe *sqe) |
| int ret; |
| |
| /* Still need defer if there is pending req in defer list. */ |
| - if (!req_need_defer(req) && list_empty(&ctx->defer_list)) |
| + if (!req_need_defer(req) && list_empty_careful(&ctx->defer_list)) |
| return 0; |
| |
| if (!req->io && io_alloc_async_ctx(req)) |
| -- |
| 2.20.1 |
| |
