From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EEC62DCF6C; Tue, 8 Sep 2026 20:50:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788900655; cv=none; b=mUpqwa1uwxH6Dj8nTFp6b72I1kopSdHkTBIt8qg1noHJAG4DhOs8LE87d2tU7vk96C+gj3e3W35Hd/FFLHwm0u5TCatlAHCrg8XR+Y9QPfM4Z4mUfQUaF5fweA6xWqupo3GbcKKPGTqCA0i+CNvz696CcSpfyT59td+8Wg2c008= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788900655; c=relaxed/simple; bh=vD8pyvJH9zExt6WnCQIxdMdMPT7fIPfl/Tt6ZaSa2io=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=ESuy31WMHPxkUE0umweR44S0PdT2pqtcbqC1HHisvbdeOiqniFx5aQM0qbUCCzBZ383XvSXdq9ikQcSDgxDh3PX8BbDZF9ilxe2RFQzS6Z8kQfhepagFHTrgGhRXDEPtRF8PgboWw43xLdulUnFgvy2PAmWWIeFQShmr6LjN7RA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ct01ES6L; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ct01ES6L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 458911F00A3A; Tue, 8 Sep 2026 20:50:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788900654; bh=vD8pyvJH9zExt6WnCQIxdMdMPT7fIPfl/Tt6ZaSa2io=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=Ct01ES6Luu+8LvDBzBh2nqCNSNHUgfpBzJaXjML+RJMmTOkUZQo6ubYHgsaqlIC+p 1htTPGEpYOps6ztf5bmYa4fprchScdXUpKphHZqPNbjiAI+r+kFnEQzR4CiA0D1sW0 ZdAofQpCalMdBzmLjftE1Wju59UjQWTI/ZkQUlyLaLu33YDGuxs9z5XrT+W0nKUGsE RatWbXhV8Vhivnhv9kpFYKwjpgSzjX+QOBcu2f5xhVXubc9P9VGAfXtlOq8nCTouHl yTwyu4T2glKdWqPZ11eCcGzyfzfcTJijoFh9RKQ5tDhl3jal/IURHmWhVPSM4gRdpl 1U32vRYkpzBVA== From: sashiko-bot@kernel.org Subject: Re: [PATCH 37/39] fuse: dax: do not set VM_MIXEDMAP Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Vasily Gorbik" , bpf@vger.kernel.org, linux-scsi@vger.kernel.org, kvmarm@lists.linux.dev, "Heiko Carstens" , kvm@vger.kernel.org, "Marc Zyngier" , "Oliver Upton" , linux-s390@vger.kernel.org, "Alexander Gordeev" , "Christian Borntraeger" , dri-devel@lists.freedesktop.org, selinux@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org In-Reply-To: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-37-dacf19cce22b@kernel.org> References: <20260908-b4-mmap-prepare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org> <20260908-b4-mmap-prepare-vma-flag-sanify-v1-37-dacf19cce22b@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 08 Sep 2026 20:50:52 +0000 Message-Id: <20260908205053.458911F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > 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/20260908-b4-mmap-pr= epare-vma-flag-sanify-v1-0-dacf19cce22b@kernel.org?part=3D37