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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 09121CA0FED for ; Wed, 10 Sep 2025 21:38:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 14D388E0002; Wed, 10 Sep 2025 17:38:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0FDC48E0001; Wed, 10 Sep 2025 17:38:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F078B8E0002; Wed, 10 Sep 2025 17:38:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id DEB388E0001 for ; Wed, 10 Sep 2025 17:38:51 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 5D0AA1402CE for ; Wed, 10 Sep 2025 21:38:51 +0000 (UTC) X-FDA: 83874655662.22.D51061A Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf04.hostedemail.com (Postfix) with ESMTP id 7D79840006 for ; Wed, 10 Sep 2025 21:38:49 +0000 (UTC) Authentication-Results: imf04.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ERlNyzA+; spf=pass (imf04.hostedemail.com: domain of akpm@linux-foundation.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1757540329; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=S4ITsVV/t8NbwT/7z/WdcHjGwXQmr80hXTyJJR6KQFs=; b=jUSwU1VpzBNpIeah1g7iJzyq+FkPiGVVFwQkNkUB4rlGrxISX10a6UyR7J8aysbPQxn4sY wp4B6+9GIe6Kyoz9X4qKoh6hzfwdrOFEmEnk9rclkRhEa0lnyH5SsPCuSrVQmAcMHUllNO ClRw9Kpe9eP3ZiZTWQVfyQ0qChrEFPU= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1757540329; a=rsa-sha256; cv=none; b=6YSFcgLCtXd6EGQuwFTzoJy/VfbslSkP4I5qLyCA8fNuyei1NAO+6G6XJPq/wy9gTtequr EuPli5ToVrDDQgqitytOTmejlZBVjnQRw2WRweyLkMg+wmzk8HEn3m2Y4oN/pScCC1x4ho MV2uO/hp3L8BEtDcqRQmMuGaLm3/55E= ARC-Authentication-Results: i=1; imf04.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ERlNyzA+; spf=pass (imf04.hostedemail.com: domain of akpm@linux-foundation.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 012C8444CE; Wed, 10 Sep 2025 21:38:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16257C4CEEB; Wed, 10 Sep 2025 21:38:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1757540327; bh=M0egxu8FbVh7lEFbI9KpqlK3Xem+oaa7R3cdZDtUNQQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ERlNyzA+aJCVNQscjQFOcHN3rHi5u0odDg8HJ53DGP17XEJUpaKk2IgWSZVS/hpeF 5p1Ihuc6sdEVaV7cYZYmFtUpA2LlaeGvkTYNkZIfig/XRZmY6YJGSG8lm1Xuk3QIE8 jwrcsmPjtEE9QD5hE3bNL3Ol+tJm9HLfh0DU00FI= Date: Wed, 10 Sep 2025 14:38:45 -0700 From: Andrew Morton To: Lorenzo Stoakes Cc: Jonathan Corbet , Matthew Wilcox , Guo Ren , Thomas Bogendoerfer , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , "David S . Miller" , Andreas Larsson , Arnd Bergmann , Greg Kroah-Hartman , Dan Williams , Vishal Verma , Dave Jiang , Nicolas Pitre , Muchun Song , Oscar Salvador , David Hildenbrand , Konstantin Komarov , Baoquan He , Vivek Goyal , Dave Young , Tony Luck , Reinette Chatre , Dave Martin , James Morse , Alexander Viro , Christian Brauner , Jan Kara , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Hugh Dickins , Baolin Wang , Uladzislau Rezki , Dmitry Vyukov , Andrey Konovalov , Jann Horn , Pedro Falcato , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-csky@vger.kernel.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-mm@kvack.org, ntfs3@lists.linux.dev, kexec@lists.infradead.org, kasan-dev@googlegroups.com, Jason Gunthorpe Subject: Re: [PATCH v2 00/16] expand mmap_prepare functionality, port more users Message-Id: <20250910143845.7ecfed713e436ed532c93491@linux-foundation.org> In-Reply-To: References: X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 7D79840006 X-Stat-Signature: 7hkap1bdq1zgu38tu8x4bp8ysbecofck X-Rspam-User: X-HE-Tag: 1757540329-722406 X-HE-Meta: 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 rgXGpGHp Nn1aEcOKoYwLSvcZAicmzUij8mAoTJBAKCn3wrQdql54Mk02sikzAVgknfDtDxl6yAaIJk1iAP/FnaoA5fPs6FzVZHN8WKjGhwwS4S8YUTc1FzdnOag9Vz3wpYTTlXl2Uu45DZBQ1pjsh+11jL7NOxJGRvmAiGy8HOsSPTZkxd5pg9ahP/JnhKnfT5zf5k4up94/e9P9UEd9Gw3Mk8jCBJqI3ida77ARtXtxR57ur+MYjrfrB586aYQyZkEqiuHHzwtJVY5BYesnAN3PR1vV2zjhZli+BWpOyEh0oVMd5CpXfOyosA8KlQK9aMKtVE6sL25R7mJN75x7sBgMSeC0UIakY+OnmN9rGZ1/ym/Cy6H6UwPQ= 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: List-Subscribe: List-Unsubscribe: On Wed, 10 Sep 2025 21:21:55 +0100 Lorenzo Stoakes wrote: > Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file > callback"), The f_op->mmap hook has been deprecated in favour of > f_op->mmap_prepare. > > This was introduced in order to make it possible for us to eventually > eliminate the f_op->mmap hook which is highly problematic as it allows > drivers and filesystems raw access to a VMA which is not yet correctly > initialised. > > This hook also introduced complexity for the memory mapping operation, as > we must correctly unwind what we do should an error arises. > > Overall this interface being so open has caused significant problems for > us, including security issues, it is important for us to simply eliminate > this as a source of problems. > > Therefore this series continues what was established by extending the > functionality further to permit more drivers and filesystems to use > mmap_prepare. Cool, I'll add this to mm-new but I'll suppress the usual emails.