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 X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC692C10DCE for ; Sat, 14 Mar 2020 00:26:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AF7322074C for ; Sat, 14 Mar 2020 00:26:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1584145571; bh=QCJXaWayMi2OcBWL1p7X8+K0nBPYK7qrl1KuOk35RlA=; h=References:In-Reply-To:From:Date:Subject:To:Cc:List-ID:From; b=1tKIBQdwPTkMqzk+bFZKlqt2s9l1+AdvhbGsww6kj1sn1Rruqdcw8ynKXMYxMhrNt 1Oj6QHjk6OOcMxlJdnZ9niD9vNP08ltTUR/qVO5A2ucVNxKzSKrtTt+6RFeXwWeYOE 1xoex6ZxdW8URU1fIZn1jiLrAmFZSQ+tayFJnNm4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727710AbgCNA0H (ORCPT ); Fri, 13 Mar 2020 20:26:07 -0400 Received: from mail-lj1-f196.google.com ([209.85.208.196]:43489 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726853AbgCNA0G (ORCPT ); Fri, 13 Mar 2020 20:26:06 -0400 Received: by mail-lj1-f196.google.com with SMTP id r7so12492192ljp.10 for ; Fri, 13 Mar 2020 17:26:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=MSh28SDxVzmezso0eCx9OLP79cE1ODkRapdHxbtQ29k=; b=BNv0AIG2vvEkCJhWjYAFISduPkxT8Ox6Ts9OSN0YQy6/mTiU5c1VgmXW9TIdC5BBr0 KYAilKkOKlN+NxaDs6MkVZ5h/TBABtDs3eTS4Nt7RYDT2QWUsCchxU4pciiLd08QlnBa KZT/V9/rFMliX2+Xv/SYsgO+HqZN1TDNaV7gs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=MSh28SDxVzmezso0eCx9OLP79cE1ODkRapdHxbtQ29k=; b=cZx5W19AA1c0zf/5Scodfk99v4Y/NKm94aFj6lE5PXtiQQpXdCpDIbntuTWxg+vilm mLLOci9GTfcKIu/pMLbd4w0f4aO4c9ZcLaQ/ftdn6OHglwQwjVptE2sbkNpa7Iiel+HY 3vtT81FcveaNaX34HwIgLAUaYmALno7KSAcIAU3byL91NQLI91lhFWRhgcpryALtSnDJ RlFLtORTtPRjxrOvlDhmFdkfm0mcuQo0WQSubXypkWbnJ4JFZGv7Ffabkxc2TBCg1lVO hOJdO5QuDHSZhPrXvVvjPnvgVUqASbbrDOcxcERiQ1kn0NJTgwoGUy6BhbgdqbrQ+wyc SuPQ== X-Gm-Message-State: ANhLgQ30y6opJnJWT+3onnvm3iYuHIaRr3/wg7z2271cM0hcng7d2bRL 1xaIuWWItaUekqlSSh3UwgNstxCp1Fk= X-Google-Smtp-Source: ADFU+vspjwA8cfiiguRvGhuudFxi2U0FjvNx9lCWdh0f43p8/jO5KMASpJSPZR2b8Fu/B1Qq6cCuAg== X-Received: by 2002:a05:651c:445:: with SMTP id g5mr9846279ljg.149.1584145563688; Fri, 13 Mar 2020 17:26:03 -0700 (PDT) Received: from mail-lf1-f47.google.com (mail-lf1-f47.google.com. [209.85.167.47]) by smtp.gmail.com with ESMTPSA id s7sm12588064lfp.51.2020.03.13.17.26.02 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 13 Mar 2020 17:26:02 -0700 (PDT) Received: by mail-lf1-f47.google.com with SMTP id n13so7518297lfh.5 for ; Fri, 13 Mar 2020 17:26:02 -0700 (PDT) X-Received: by 2002:ac2:5986:: with SMTP id w6mr9900471lfn.30.1584145562223; Fri, 13 Mar 2020 17:26:02 -0700 (PDT) MIME-Version: 1.0 References: <20200313235303.GP23230@ZenIV.linux.org.uk> <20200313235357.2646756-1-viro@ZenIV.linux.org.uk> <20200313235357.2646756-11-viro@ZenIV.linux.org.uk> In-Reply-To: <20200313235357.2646756-11-viro@ZenIV.linux.org.uk> From: Linus Torvalds Date: Fri, 13 Mar 2020 17:25:46 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC][PATCH v4 11/69] lookup_fast(): consolidate the RCU success case To: Al Viro Cc: linux-fsdevel , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 13, 2020 at 4:55 PM Al Viro wrote: > > - if (unlikely(negative)) > + if (unlikely(!inode)) > return -ENOENT; Isn't that buggy? Despite the name, 'inode' isn't an inode pointer. It's a pointer to the return location. I think the test should be if (unlikely(!*inode)) return -ENOENT; and I also suspect that the argument name should be fixed (maybe "inodepp", maybe something better). Because the "inode" pointer itself always exists. The callers will have something like struct inode *inode; and then pass in "&inode" to the function. And it's possible that I'm talking complete garbage. Linus