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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1B5ECC83F12 for ; Tue, 29 Aug 2023 13:03:38 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5E4558E0027; Tue, 29 Aug 2023 09:03:38 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 56D158E001A; Tue, 29 Aug 2023 09:03:38 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 40EC68E0027; Tue, 29 Aug 2023 09:03:38 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 2DCD48E001A for ; Tue, 29 Aug 2023 09:03:38 -0400 (EDT) Received: from smtpin18.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 06C891C8A4E for ; Tue, 29 Aug 2023 13:03:38 +0000 (UTC) X-FDA: 81177158916.18.1E81BB8 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf19.hostedemail.com (Postfix) with ESMTP id 966091A0017 for ; Tue, 29 Aug 2023 13:03:34 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; spf=none (imf19.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1693314215; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KCKLsw2luDg+ufhtBmnGZmmgDMOsylBVvKdrvYUCWaY=; b=6bmmaNafF6abyWhNyM++DMlCy1C6J6oE2nnRAIeucCp5LJUM7PJHR3YeD48JCgWDIVWYPC EORyilAqGDZLWE7cyV/5bx+YJ+xjdR+DTHP3ev52Yg0vC+q2h4zOQvwA+ymLBYv4Hcgraz VD1ieBkZPsXGa5HK5DALaeIdIqNb++M= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1693314215; a=rsa-sha256; cv=none; b=RPTSQrWeZs8qLnTBvRRHRWWuA+7m5+u+NuE3OtD34wcMMknmFBaoJi+Yqq1x1vz+aK9yUm XqqT2KyfU+KTljKDa82stVUbILK6bUsnSvvo5RjxtG95/wy4Cus7PvAVSme1mA5ytthmcW ZWXmWUSGlLMs1RHzXrKp1Lzq/aAH8Es= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; spf=none (imf19.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de; dmarc=none Received: by verein.lst.de (Postfix, from userid 2407) id 93D3A6732D; Tue, 29 Aug 2023 15:03:27 +0200 (CEST) Date: Tue, 29 Aug 2023 15:03:27 +0200 From: Christoph Hellwig To: Al Viro Cc: Christoph Hellwig , Jens Axboe , "Darrick J. Wong" , Andrew Morton , Matthew Wilcox , Christian Brauner , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/6] block: open code __generic_file_write_iter for blkdev writes Message-ID: <20230829130327.GA26482@lst.de> References: <20230801172201.1923299-1-hch@lst.de> <20230801172201.1923299-4-hch@lst.de> <20230829020614.GB325446@ZenIV> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230829020614.GB325446@ZenIV> User-Agent: Mutt/1.5.17 (2007-11-01) X-Stat-Signature: hcpg5kk7tug6oan955jnuem3g6sati71 X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 966091A0017 X-Rspam-User: X-HE-Tag: 1693314214-132154 X-HE-Meta: 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 gizIEJ7T FAGiii8H2MktQAMOgUsJ3KY6srv3xP7qVGphuBihv+vZSZMYwfdI2KpcD0Q9hVWn2mQWjLwgzZrAKSYXE8fwdPq5vQ7OwQxnwcNpFuGDGIT+0+2M= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Aug 29, 2023 at 03:06:14AM +0100, Al Viro wrote: > On Tue, Aug 01, 2023 at 07:21:58PM +0200, Christoph Hellwig wrote: > > @@ -569,7 +594,23 @@ static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) > > iov_iter_truncate(from, size); > > } > > > > - ret = __generic_file_write_iter(iocb, from); > > + ret = file_remove_privs(file); > > + if (ret) > > + return ret; > > That chunk is a bit of a WTF generator... Thankfully, > > static int __file_remove_privs(struct file *file, unsigned int flags) > { > struct dentry *dentry = file_dentry(file); > struct inode *inode = file_inode(file); > int error = 0; > int kill; > > if (IS_NOSEC(inode) || !S_ISREG(inode->i_mode)) > return 0; > > means that it's really a no-op. But I'd still suggest > removing it, just to reduce the amount of head-scratching > for people who'll be reading that code later... I'll send an incremental patch to remove it once the changes hit Linus' tree.