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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 F2F47C433E0 for ; Thu, 11 Jun 2020 02:17:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CB0D1206A4 for ; Thu, 11 Jun 2020 02:17:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CB0D1206A4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 673A68D0072; Wed, 10 Jun 2020 22:17:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6253F8D004C; Wed, 10 Jun 2020 22:17:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 562118D0072; Wed, 10 Jun 2020 22:17:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0134.hostedemail.com [216.40.44.134]) by kanga.kvack.org (Postfix) with ESMTP id 3D7A08D004C for ; Wed, 10 Jun 2020 22:17:31 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 037DC180AEF50 for ; Thu, 11 Jun 2020 02:17:30 +0000 (UTC) X-FDA: 76915319502.26.hands22_470a1bc26dd0 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin26.hostedemail.com (Postfix) with ESMTP id B88491804B667 for ; Thu, 11 Jun 2020 02:17:30 +0000 (UTC) X-HE-Tag: hands22_470a1bc26dd0 X-Filterd-Recvd-Size: 2096 Received: from ZenIV.linux.org.uk (zeniv.linux.org.uk [195.92.253.2]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Thu, 11 Jun 2020 02:17:30 +0000 (UTC) Received: from viro by ZenIV.linux.org.uk with local (Exim 4.93 #3 (Red Hat Linux)) id 1jjCmE-006lY6-E3; Thu, 11 Jun 2020 02:17:10 +0000 Date: Thu, 11 Jun 2020 03:17:10 +0100 From: Al Viro To: Matthew Wilcox Cc: Mike Kravetz , Miklos Szeredi , kbuild test robot , kbuild-all@lists.01.org, Colin Walters , syzbot , Andrew Morton , Linux Memory Management List , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs , overlayfs Subject: Re: [PATCH v2] ovl: provide real_file() and overlayfs get_unmapped_area() Message-ID: <20200611021710.GA23230@ZenIV.linux.org.uk> References: <4ebd0429-f715-d523-4c09-43fa2c3bc338@oracle.com> <202005281652.QNakLkW3%lkp@intel.com> <365d83b8-3af7-2113-3a20-2aed51d9de91@oracle.com> <20200611003726.GY23230@ZenIV.linux.org.uk> <20200611013616.GM19604@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200611013616.GM19604@bombadil.infradead.org> X-Rspamd-Queue-Id: B88491804B667 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam05 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 Wed, Jun 10, 2020 at 06:36:16PM -0700, Matthew Wilcox wrote: > while (file->f_mode & FMODE_OVL_UPPER) > file = file->private_data; > return file; > > Or are you proposing that overlayfs copy FMODE_HUGEPAGES from the > underlying fs to the overlaying fs? The latter - that way nobody outside of overlayfs needs to know what its ->private_data points to, for one thing. And it's cheaper that way, obviously.