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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 EA359C35280 for ; Fri, 8 May 2020 02:21:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC3AC208D6 for ; Fri, 8 May 2020 02:21:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588904505; bh=eMa8tLwnSHRxwruBW3dkjHyZBh4W1anjA0G4uo09nLI=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=IOsVrU/OaoKTN4rV31jrnhk637ZBdGPNG1+ekQHg0RWXYmOtXdB7lkAIza9hX53kt vVNDDMLt9Lcg9LmCQyrf5nV7yqpRmcQSlb3rRQyf0GHWmE8Cxj6OfOU+f8zvdszTz3 0kSVcOSnOB3Hbebn9MSnQ14TTdQOiEpUE6KnFA9s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726689AbgEHCVm (ORCPT ); Thu, 7 May 2020 22:21:42 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:40539 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726509AbgEHCVm (ORCPT ); Thu, 7 May 2020 22:21:42 -0400 Received: by mail-pj1-f67.google.com with SMTP id fu13so3532196pjb.5; Thu, 07 May 2020 19:21:41 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=sCk5Kz/L26R1qfSoCe3hO4Rdhm8Vcm0AKmqx9EEaRqs=; b=GgrSEpYxmRnwgkfEMzNHaEEGcXonN62oS7LQy87JSRzcfQdgUqNUpqWjSvp0Fi4rpu IGWc5WQE+UaFJsEQCLzNvqBkIxoMlraK4+mv45CRctt77REW3y29/t0OSF00fJpi0Kwy jU8ogrUWcPwO1GsuV7iJGLV1otzYgKV1YWXopii6ueYQeXa8b7J6tl9u/pTelgl46Ngg LWsOiRu9dxlkGfGqlOZNfMxSwGCItvVDKLEufISC0EshLWeNuS3vCKOK4b9APicoBNX6 Ee80nLns+YcFiJTqHDrJ17hGjuHE36acW5GVCPUZJ1dIHmlpNSjIHfOhLR6zcWILqzCm fKlw== X-Gm-Message-State: AGi0PubStuagHkGFZss0QGBDHY8R1c8IqDDRmJtwvqD0xKjBqV6SAsDC Q5MV3PAzq53sR492kI2I6uI= X-Google-Smtp-Source: APiQypLH3bqzMjxBt959/wwSgBKL1pGSXtPpBArl9pMYffCVuSDie8PJG/ipY+C3Q4wfk1BvF3nCEw== X-Received: by 2002:a17:902:7c98:: with SMTP id y24mr161013pll.37.1588904500948; Thu, 07 May 2020 19:21:40 -0700 (PDT) Received: from 42.do-not-panic.com (42.do-not-panic.com. [157.230.128.187]) by smtp.gmail.com with ESMTPSA id g10sm109531pfk.103.2020.05.07.19.21.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2020 19:21:40 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id 7425F403EA; Fri, 8 May 2020 02:21:39 +0000 (UTC) Date: Fri, 8 May 2020 02:21:39 +0000 From: Luis Chamberlain To: Al Viro Cc: Shuah Khan , axboe@kernel.dk, zohar@linux.vnet.ibm.com, keescook@chromium.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] fs: avoid fdput() after failed fdget() in ksys_sync_file_range() Message-ID: <20200508022139.GD11244@42.do-not-panic.com> References: <31be6e0896eba59c06eb9d3d137b214f7220cc53.1588894359.git.skhan@linuxfoundation.org> <20200508000509.GK23230@ZenIV.linux.org.uk> <20200508002422.GL23230@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200508002422.GL23230@ZenIV.linux.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, May 08, 2020 at 01:24:22AM +0100, Al Viro wrote: > On Fri, May 08, 2020 at 01:05:09AM +0100, Al Viro wrote: > > On Thu, May 07, 2020 at 05:57:09PM -0600, Shuah Khan wrote: > > > Fix ksys_sync_file_range() to avoid fdput() after a failed fdget(). > > > fdput() doesn't do fput() on this file since FDPUT_FPUT isn't set > > > in fd.flags. Fix it anyway since failed fdget() doesn't require > > > a fdput(). > > > > > > This was introdcued in a commit to add sync_file_range() helper. > > > > Er... What's the point microoptimizing the slow path here? > > PS: I'm not saying the patch is incorrect, but Fixes: is IMO over the > top. And looking at that thing, > { > struct fd f = fdget(fd); > int ret; > > if (unlikely(!f.file)) > return -EBADF; > > ret = sync_file_range(f.file, offset, nbytes, flags); > fdput(f); > return ret; > } > > might be cleaner, but that's a matter of taste... This makes it easier to read. Luis