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 6BF4DC433F5 for ; Wed, 11 May 2022 19:01:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346513AbiEKTBl (ORCPT ); Wed, 11 May 2022 15:01:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47032 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345744AbiEKTBk (ORCPT ); Wed, 11 May 2022 15:01:40 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AF9A443D2 for ; Wed, 11 May 2022 12:01:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 49BD2B8260B for ; Wed, 11 May 2022 19:01:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E6BF7C340EE; Wed, 11 May 2022 19:01:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1652295696; bh=yFAu4NtfyG/gBAE+EMMRtmsQvCPj7mkWnx/0WKtfGN8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FVEMR5yZnQEYf5f604+3xYnL8nhJW5pg0lYzw/YXrvGc9dmSxjHsI5rbeGG1Cw8Df 0XLp/ufoQhcZbpZQLlyaXSXQUDAj2F6yE9QzUkqMKK1RD3gaJY8BGvQysH3vfpMfv7 c+ssVkMduCkU8CXNTfOl0rG7cgP8xNmp8CdushYV/3rmC3pRwlMyU7zy5oubWA16EQ IH93SLfhs2alOssWM7kpiaBjZ/Suas/0O1KJquFaNV3AXBtmxSDETlYCNlgcXYHBfS 3JndpOfs8X10qBxPlFzOw8FA4soiwKSSYD/v/xwWN21idlp+fSrm2ULvelGgBWinol PCOqKou/g+qIw== Date: Wed, 11 May 2022 19:01:34 +0000 From: Eric Biggers To: Matthew Wilcox Cc: Chengguang Xu , viro@zeniv.linux.org.uk, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] vfs: move fdput() to right place in ksys_sync_file_range() Message-ID: References: <20220511154503.28365-1-cgxu519@mykernel.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, May 11, 2022 at 04:51:34PM +0100, Matthew Wilcox wrote: > On Wed, May 11, 2022 at 11:45:03AM -0400, Chengguang Xu wrote: > > Move fdput() to right place in ksys_sync_file_range() to > > avoid fdput() after failed fdget(). > > Why? fdput() is already conditional on FDPUT_FPUT so you're ... > optimising the failure case? "fdput() after failed fdget()" has confused people before, so IMO it's worth cleaning this up. But the commit message should make clear that it's a cleanup, not a bug fix. Also I recommend using an early return: f = fdget(fd); if (!f.file) return -EBADF; ret = sync_file_range(f.file, offset, nbytes, flags); fdput(f); return ret;