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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3D7CC433EF for ; Mon, 18 Oct 2021 07:05:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8557361027 for ; Mon, 18 Oct 2021 07:05:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230312AbhJRHHS (ORCPT ); Mon, 18 Oct 2021 03:07:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58530 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229533AbhJRHHR (ORCPT ); Mon, 18 Oct 2021 03:07:17 -0400 Received: from mail-io1-xd34.google.com (mail-io1-xd34.google.com [IPv6:2607:f8b0:4864:20::d34]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74FAFC06161C; Mon, 18 Oct 2021 00:05:06 -0700 (PDT) Received: by mail-io1-xd34.google.com with SMTP id m20so14999601iol.4; Mon, 18 Oct 2021 00:05:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jXX2fvCmjdLfrYBH5s0iu5Hk0ygNOTdaxa2SFqxVg2o=; b=KwRUqOxq0BaLUI4zLOEo1NnfrM/jGSTl3YvpCpYuUJR7qlW5HB1/vSGExx8EXOKNyg t4Vqi+2FowA/fBESkiIm2RyKCnJSE4tFeCFmYDqAjCgCH2T7n2/voLU9lapGbijgMlk9 rR/w+9B5pYujdbteQUJhCcc26X/SKO9RyLWJMt11djVlmx59QDQoZKhNrR59oF+8arcW 1BBJzvWpvUlEMd0GOnHYpVyE7g9svRvluXVad+dZLSoUD1JtGf1kJJS1ArzlZJPw6INj +8nqw9hxLCGj1rye2xtA3JHklDGTvh7eSGv4G5KqRAd2/MgMaVz2IkxYBvcEnagBN9oB ezxg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jXX2fvCmjdLfrYBH5s0iu5Hk0ygNOTdaxa2SFqxVg2o=; b=xkHXybl9MaC0U8NjE+RFdLDqeGXAmPo5nipJrU9maPo0hU3t3zaglWkyJyHbT7oVeG 42a38ddCrcQWP9e8JkkLBsORI6J4w8WqPUwA3QgG4Tu/arF9a2rbeOVK34ZXJUPlKWgX tPQMj77AqXpr6QHvWIGa3+Jtl3mTZnZNLifpYEqD423GBLzVxHOum0D82huObWr7nvpO Lj56PnpFOUgxjkQvtIcMeJrRHrhcRkGw9BO3a9U4zSPxy10KlSmskMoMmITMvIGFGw0C Lawbau/S+au8RHWw11EunvoZsfZ4kS5HUWxCMwC7J9D1ndn+DJQz3ezZ81ksXfh1wi/N 6IlA== X-Gm-Message-State: AOAM533W9hxLM6/GNmke9VeMLG04eX30uQs1TzMXbcL0u5KnZE4vjcFP NftN0UtYdqDih3Mh3NtWSSo= X-Google-Smtp-Source: ABdhPJxTFSBXKNvkHFBIftPsm1AnvyVbhWIRNBoda1E/eesEY/lLMI/Z8r0sUYtkQhFxLMVr4bpUWw== X-Received: by 2002:a05:6602:2d85:: with SMTP id k5mr13266775iow.92.1634540705528; Mon, 18 Oct 2021 00:05:05 -0700 (PDT) Received: from localhost.localdomain (node-17-161.flex.volo.net. [76.191.17.161]) by smtp.googlemail.com with ESMTPSA id g3sm6782727ile.61.2021.10.18.00.05.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 18 Oct 2021 00:05:05 -0700 (PDT) From: Noah Goldstein Cc: goldstein.w.n@gmail.com, axboe@kernel.dk, asml.silence@gmail.com, io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v1] fs/io_uring: Hoist ret2 == -EAGAIN check in tail of io_write Date: Mon, 18 Oct 2021 03:02:43 -0400 Message-Id: <20211018070242.20325-1-goldstein.w.n@gmail.com> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit To: unlisted-recipients:; (no To-header on input) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit reorganizes the branches in the tail of io_write so that the 'ret2 == -EAGAIN' check is not repeated and done first. The previous version was duplicating the 'ret2 == -EAGAIN'. As well 'ret2 != -EAGAIN' gurantees the 'done:' path so it makes sense to move that check to the front before the likely more expensive branches which require memory derefences. Signed-off-by: Noah Goldstein --- Generally I would want to rewrite this as: ``` if (ret2 != -EAGAIN || (req->flags & REQ_F_NOWAIT) || (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))) kiocb_done(kiocb, ret2, issue_flags); else { ... ``` But the style of the file seems to be to use gotos. If the above is prefereable, let me know and I'll post a new version. fs/io_uring.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index d1e672e7a2d1..932fc84d70d3 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -3648,12 +3648,15 @@ static int io_write(struct io_kiocb *req, unsigned int issue_flags) */ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT)) ret2 = -EAGAIN; + + if (ret2 != -EAGAIN) + goto done; /* no retry on NONBLOCK nor RWF_NOWAIT */ - if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT)) + if (req->flags & REQ_F_NOWAIT) goto done; - if (!force_nonblock || ret2 != -EAGAIN) { + if (!force_nonblock) { /* IOPOLL retry should happen for io-wq threads */ - if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL)) + if (req->ctx->flags & IORING_SETUP_IOPOLL) goto copy_iov; done: kiocb_done(kiocb, ret2, issue_flags); -- 2.29.2