From patchwork Wed Nov 23 11:33:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pavel Begunkov X-Patchwork-Id: 13053514 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 52D9CC46467 for ; Wed, 23 Nov 2022 11:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237271AbiKWLfL (ORCPT ); Wed, 23 Nov 2022 06:35:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44566 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237278AbiKWLfF (ORCPT ); Wed, 23 Nov 2022 06:35:05 -0500 Received: from mail-wm1-x332.google.com (mail-wm1-x332.google.com [IPv6:2a00:1450:4864:20::332]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1B9010EA1A for ; Wed, 23 Nov 2022 03:35:03 -0800 (PST) Received: by mail-wm1-x332.google.com with SMTP id v124-20020a1cac82000000b003cf7a4ea2caso1200862wme.5 for ; Wed, 23 Nov 2022 03:35:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=A0DW1JSauK3bY460xsnmlLPiYfNI+QTI3O3eNQDmUns=; b=YtnIqCvh/xgvy2X9x1j79mdcWmrmExXdVsfIXSyqnntQIF//PNQYWkV51zvtgmJb6W KgWaD3VvK55Qf5pRiephud5trgZiSVOvh/1ApBsOKHd/HVJNUepBSnUKrVsY+6+M40mc XB4+8OSY5IXv2mqqNOl98xxJWVqwgkCLyuTkc76yh6CdId934tCte8HqpL7JL05cHKVg fUJspkR3FoAeHwzZqrl/MlqHy6XjsvglQKY7SaPM3QM15FVmgYzs41LknLka+1bBum0o LvGAhdCITvWcTVAmlUjxpv6BgMhQowb/W5IIxFq3QtfGesQyOi8cJSZOVkrBXbg178Jw A4WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=A0DW1JSauK3bY460xsnmlLPiYfNI+QTI3O3eNQDmUns=; b=nxw4dyWGDXwFJ6uum2wWqeLgxpvlHXnP9cDydbkD1jDDFoQEChXECJvMzd/8Pui/lm pmWicwheZaDOAtC2WS4bVj6tzoYOkHLwclM9gX+QhXYva13bLMhvOMZ+3xHtDqD28uHg A/u1Rj8b9qFaTqZjk5lNhpey3PHk4FMA1pTu+dnKceydrj90gt269Ebi79X+VKc71vHr yRVoSWfSr55iC+W8nSL63BaDGvIWawEZCFuRxefaPFEuhkBFwFuuYCojbh5+HAQ9P49X gubkUavU0yChU9DQoUKWUJHSxRJTuMLXlnq6Gx3cBAld44JJIdMaMOivapU7kVeac7KH /5dQ== X-Gm-Message-State: ANoB5pn29pHHiAcAPNRhD8UEJLU9DocmfH4u2tUo7W81f8ZO8846ODUA 98B6F0r1ngY2RoTVAv5RYT6h7W+q4lg= X-Google-Smtp-Source: AA0mqf7SgqYT6X2V+myj6s5fN/ozUC+QsWKUMSOVgFCHaOKBYnxkgs65F+21dXlUHtzMhQl8oBwXew== X-Received: by 2002:a05:600c:4fcd:b0:3cf:a11a:c775 with SMTP id o13-20020a05600c4fcd00b003cfa11ac775mr9466668wmq.153.1669203302272; Wed, 23 Nov 2022 03:35:02 -0800 (PST) Received: from 127.0.0.1localhost.com ([2620:10d:c092:600::2:e1b]) by smtp.gmail.com with ESMTPSA id g9-20020a05600c4ec900b003cfd58409desm2262064wmq.13.2022.11.23.03.35.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Nov 2022 03:35:01 -0800 (PST) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com Subject: [PATCH for-next 1/7] io_uring: add completion locking for iopoll Date: Wed, 23 Nov 2022 11:33:36 +0000 Message-Id: <84d86b5c117feda075471c5c9e65208e0dccf5d0.1669203009.git.asml.silence@gmail.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org There are pieces of code that may allow iopoll to race filling cqes, temporarily add spinlocking around posting events. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov --- io_uring/rw.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/io_uring/rw.c b/io_uring/rw.c index 1ce065709724..61c326831949 100644 --- a/io_uring/rw.c +++ b/io_uring/rw.c @@ -1049,6 +1049,7 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) else if (!pos) return 0; + spin_lock(&ctx->completion_lock); prev = start; wq_list_for_each_resume(pos, prev) { struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list); @@ -1063,11 +1064,11 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin) req->cqe.flags = io_put_kbuf(req, 0); __io_fill_cqe_req(req->ctx, req); } - + io_commit_cqring(ctx); + spin_unlock(&ctx->completion_lock); if (unlikely(!nr_events)) return 0; - io_commit_cqring(ctx); io_cqring_ev_posted_iopoll(ctx); pos = start ? start->next : ctx->iopoll_list.first; wq_list_cut(&ctx->iopoll_list, prev, start);