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=-2.3 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,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 5F902C742BA for ; Fri, 12 Jul 2019 12:56:27 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 345B120863 for ; Fri, 12 Jul 2019 12:56:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="q0Z/ShlB" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 345B120863 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5OML+HizGRvJsNVTh4HUEY3NrX4Nh8XlXIaTnvzBXDw=; b=q0Z/ShlBmWWyNG XqRIHVuNP9v7diw9bxDb90AXcx/drY+3iIYFKp98vJv/yTnEdS5q8xTF/54ncySfrFA3qq7VOMf1b mTDTRelbDz0/H8TnYsSHNtQXaIdJMHr89WWAnS4xu4PDcvf1ccpC7XLNTSadJgxR18xqQzMh9DvL9 ZGmhHBkObWGhnVtWbGHLxtl7qdM6xXwXpObT+83kTTMPeh9l37N2W+BIXYOeG/DrPk0FSeaWY6cLa fnU3tCW4A8zIDGEVJGzBgyD5Xb8OKi11u3EBBlx3WtrG2RFlrl9x7lcPRyhXekSEsSeJw88F6kHfi 7XXlKfVceo/eLCz0cm7w==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hlv68-0002NE-Am; Fri, 12 Jul 2019 12:56:24 +0000 Received: from zeniv.linux.org.uk ([195.92.253.2]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hlv64-0002L1-D2 for linux-arm-kernel@lists.infradead.org; Fri, 12 Jul 2019 12:56:21 +0000 Received: from viro by ZenIV.linux.org.uk with local (Exim 4.92 #3 (Red Hat Linux)) id 1hlv5c-0007Pc-Mt; Fri, 12 Jul 2019 12:55:52 +0000 Date: Fri, 12 Jul 2019 13:55:52 +0100 From: Al Viro To: Aleksa Sarai Subject: Re: [PATCH v9 05/10] namei: O_BENEATH-style path resolution flags Message-ID: <20190712125552.GL17978@ZenIV.linux.org.uk> References: <20190706145737.5299-1-cyphar@cyphar.com> <20190706145737.5299-6-cyphar@cyphar.com> <20190712043341.GI17978@ZenIV.linux.org.uk> <20190712105745.nruaftgeat6irhzr@yavin> <20190712123924.GK17978@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190712123924.GK17978@ZenIV.linux.org.uk> User-Agent: Mutt/1.11.3 (2019-02-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190712_055620_455971_854BA765 X-CRM114-Status: GOOD ( 14.61 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, linux-sh@vger.kernel.org, Alexei Starovoitov , linux-kernel@vger.kernel.org, David Howells , linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, Shuah Khan , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Tycho Andersen , Aleksa Sarai , linux-arm-kernel@lists.infradead.org, linux-mips@vger.kernel.org, linux-xtensa@linux-xtensa.org, Kees Cook , Arnd Bergmann , Jann Horn , linuxppc-dev@lists.ozlabs.org, linux-m68k@lists.linux-m68k.org, Andy Lutomirski , Shuah Khan , David Drysdale , Christian Brauner , "J. Bruce Fields" , linux-parisc@vger.kernel.org, linux-api@vger.kernel.org, Chanho Min , Jeff Layton , Oleg Nesterov , Eric Biederman , linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Linus Torvalds , containers@lists.linux-foundation.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Jul 12, 2019 at 01:39:24PM +0100, Al Viro wrote: > On Fri, Jul 12, 2019 at 08:57:45PM +1000, Aleksa Sarai wrote: > > > > > @@ -2350,9 +2400,11 @@ static const char *path_init(struct nameidata *nd, unsigned flags) > > > > s = ERR_PTR(error); > > > > return s; > > > > } > > > > - error = dirfd_path_init(nd); > > > > - if (unlikely(error)) > > > > - return ERR_PTR(error); > > > > + if (likely(!nd->path.mnt)) { > > > > > > Is that a weird way of saying "if we hadn't already called dirfd_path_init()"? > > > > Yes. I did it to be more consistent with the other "have we got the > > root" checks elsewhere. Is there another way you'd prefer I do it? > > "Have we got the root" checks are inevitable evil; here you are making the > control flow in a single function hard to follow. > > I *think* what you are doing is > absolute pathname, no LOOKUP_BENEATH: > set_root > error = nd_jump_root(nd) > else > error = dirfd_path_init(nd) > return unlikely(error) ? ERR_PTR(error) : s; > which should be a lot easier to follow (not to mention shorter), but I might > be missing something in all of that. PS: if that's what's going on, I would be tempted to turn the entire path_init() part into this: if (flags & LOOKUP_BENEATH) while (*s == '/') s++; in the very beginning (plus the handling of nd_jump_root() prototype change, but that belongs with nd_jump_root() change itself, obviously). Again, I might be missing something here... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel