From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D380ECAAD8 for ; Fri, 16 Sep 2022 21:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229450AbiIPVio (ORCPT ); Fri, 16 Sep 2022 17:38:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60092 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229655AbiIPVin (ORCPT ); Fri, 16 Sep 2022 17:38:43 -0400 Received: from hr2.samba.org (hr2.samba.org [IPv6:2a01:4f8:192:486::2:0]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F4B1AB430 for ; Fri, 16 Sep 2022 14:38:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=samba.org; s=42; h=Message-Id:Date:Cc:To:From; bh=5+4hNpMItLNugz0oZGYnGAzDfersrmpF1YEyKQa/3/4=; b=R3uQkQT8jt27VsilIotg/xryuj rZ7ZoM4s6YCDXFWLBvoqqas4fu7EmTE40dQGtgaGpg+sEjWI+KzeFc/8avodtDNgeZzw8CRhons/D rsdZexw0QzUU6+DVKay1sZbZzbUl3brL3gpuGHGkxRSqEz6bmP+wqZMIHk8TSo4W6U4TWm4SMb3qG SrlZ34oIdBHjeqqTgEa1IuPolX3q+ayPyB11Q8xuXBKss+VMnqRfWLwdhOdN7/SPpZgLSWSr54FrD /XhoUQrm6asy1dGCx/FkH6IJ98hC79j0B9/QpjURzs7zIzf4zMbqmvCu4vvZI/bTpuGNy/CJRlzHo ebg7f3szVBRJkqCxKmHdohLtPyZuG4SfCBg+GM5bSrJZ16pDxWL5fXTmWzaxyz7CbAOWr9CpKscPm VpOBTKXb9/8bl6Zp4yzmR81UTAjkG2wKFdYFqLqF7krpsoBQS+Toxw85CFvgBt9Vb2Jw9Mbvhk6ef t/Ng42UK82JfntZWOo3gC/xo; Received: from [127.0.0.2] (localhost [127.0.0.1]) by hr2.samba.org with esmtpsa (TLS1.3:ECDHE_SECP256R1__ECDSA_SECP256R1_SHA256__CHACHA20_POLY1305:256) (Exim) id 1oZJ2l-000j6T-RB; Fri, 16 Sep 2022 21:38:40 +0000 From: Stefan Metzmacher To: io-uring@vger.kernel.org, axboe@kernel.dk, asml.silence@gmail.com Cc: Stefan Metzmacher Subject: [PATCH 2/5] io_uring/core: move io_cqe->fd over from io_cqe->flags to io_cqe->res Date: Fri, 16 Sep 2022 23:36:26 +0200 Message-Id: X-Mailer: git-send-email 2.34.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org Both flags and res have the same lifetime currently. io_req_set_res() sets both of them. Callers of io_req_set_res() like req_fail_link_node(), io_req_complete_failed() and io_req_task_queue_fail() set io_cqe->res to their callers value and force flags to 0. The motivation for this change is the next commit, it will let us keep io_cqe->flags even on error. For IORING_OP_SEND_ZC it is needed to keep IORING_CQE_F_MORE even on a generic failure, userspace needs to know that a IORING_CQE_F_NOTIF will follow. Otherwise the buffers might be reused too early. Fixes: b48c312be05e8 ("io_uring/net: simplify zerocopy send user API") Signed-off-by: Stefan Metzmacher Cc: Pavel Begunkov Cc: Jens Axboe Cc: io-uring@vger.kernel.org --- include/linux/io_uring_types.h | 6 +++--- io_uring/io_uring.c | 10 ++++++++-- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h index 677a25d44d7f..37925db42ae9 100644 --- a/include/linux/io_uring_types.h +++ b/include/linux/io_uring_types.h @@ -473,12 +473,12 @@ struct io_task_work { struct io_cqe { __u64 user_data; - __s32 res; - /* fd initially, then cflags for completion */ + /* fd initially, then res for completion */ union { - __u32 flags; int fd; + __s32 res; }; + __u32 flags; }; /* diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c index b9640ad5069f..ae69cff94664 100644 --- a/io_uring/io_uring.c +++ b/io_uring/io_uring.c @@ -837,8 +837,6 @@ static void io_preinit_req(struct io_kiocb *req, struct io_ring_ctx *ctx) req->ctx = ctx; req->link = NULL; req->async_data = NULL; - /* not necessary, but safer to zero */ - req->cqe.res = 0; } static void io_flush_cached_locked_reqs(struct io_ring_ctx *ctx, @@ -1574,6 +1572,12 @@ static int io_issue_sqe(struct io_kiocb *req, unsigned int issue_flags) if (!def->audit_skip) audit_uring_entry(req->opcode); + /* + * req->cqe.fd was resolved by io_assign_file + * now make sure its alias req->cqe.res is reset, + * so we don't use that value by accident. + */ + req->cqe.res = -1; ret = def->issue(req, issue_flags); if (!def->audit_skip) @@ -1902,6 +1906,8 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req, state->need_plug = false; blk_start_plug_nr_ios(&state->plug, state->submit_nr); } + } else { + req->cqe.fd = -1; } personality = READ_ONCE(sqe->personality); -- 2.34.1