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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 7583DC982D2 for ; Thu, 17 Sep 2026 17:38:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BE02110F039; Thu, 17 Sep 2026 17:38:12 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="RcDwMYTW"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id D684310F039 for ; Thu, 17 Sep 2026 17:38:11 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id BB6DF4341A; Thu, 17 Sep 2026 17:38:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 145AC1F00893; Thu, 17 Sep 2026 17:38:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789666691; bh=doCNSwjURbmhHg+0frD2eI6LIXLK7q+AfOXJiRsEf+0=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=RcDwMYTWjAVjmL5SbqKtX8uLVBnIEyD/7kxdhxieXPHjp/PVkVwphRYDc+U24v+H0 BGtDABCZBYibFk3sThJZcZuHBY1inIjSG9+L084I/aALOwXP8H5T6zXmYPOYQ9mjMB QHQop8Wde9DPDWu0+CIULjegrFZZISw3W0QAIfvNdDIYttKTn19gKqNH9rsZ3pFUNr 1bDQ0yRHvdjtK+C3KEQjSWlBtd4sbXFx53kTR2OWpBW6OZdQs7Zkzm27CI3MspdIi2 HAu/buPLcR+qcZI42vC5hBJPbQUTF1WkIAPIw4K1T9cGUL2fxajdFr+ZNRgoQlkwhi r9XrrJsnn28Dw== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 38/40] fuse: dax: do not set VM_MIXEDMAP To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: bpf@vger.kernel.org, "Vasily Gorbik" , "Christian Borntraeger" , "Alexander Gordeev" , linux-rdma@vger.kernel.org, selinux@vger.kernel.org, linux-perf-users@vger.kernel.org, "Heiko Carstens" , kvmarm@lists.linux.dev, kvm@vger.kernel.org, linux-s390@vger.kernel.org, "Marc Zyngier" , "Oliver Upton" , dri-devel@lists.freedesktop.org, linux-scsi@vger.kernel.org, linux-trace-kernel@vger.kernel.org In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-38-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-38-4583d8a23bca@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 17 Sep 2026 17:38:10 +0000 Message-Id: <20260917173811.145AC1F00893@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" > Commit e1fb4a086495 ("dax: remove VM_MIXEDMAP for fsdax and device dax") > prevented fsdax and device-dax from setting VM_MIXEDMAP, as DAX no longer > relies on it to direct core mm paths. >=20 > The fuse DAX implementation, added later, copied the old pattern and still > sets it. >=20 > Fuse DAX maps pages the same way fsdax does, via dax_iomap_fault() and > ultimately vmf_insert_page_mkwrite() and vmf_insert_folio_pmd(), which > insert ordinary refcounted pages and so do not require VM_MIXEDMAP. >=20 > Setting it only serves to mark the mapping as kernel-owned, making fuse D= AX > the sole DAX implementation whose mappings are unmergeable, cannot be > mlock()'d, eagerly copy page tables on fork and reject MADV_DOFORK and > MADV_DODUMP. >=20 > It also requires vma_is_special_huge() in mm/huge_memory.c to carve DAX o= ut > of its kernel-owned check explicitly. >=20 > There is no reason for fuse DAX to keep on using this flag so drop it. >=20 > Signed-off-by: Lorenzo Stoakes (ARM) Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260917-b4-mmap-pr= epare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org?part=3D38