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 EECB74E36C3; Thu, 17 Sep 2026 17:38:11 +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=1789666693; cv=none; b=YjQcW9dIL5qRw5faQs+3agv6GnJBlsnQ3GGJ5iP0lDtvjyvaiQQuFU4fpXFqFZQJz/s6vabb9opkJ6l9BCGM0cfZ/Dhmfe157jrtwFjP9/jszjtBPFrRDmKFHTRODLpw9ruaLP8Q0KOz13w66ugFe7k4QE4BOjEB4Wpaa4ctDVI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789666693; c=relaxed/simple; bh=doCNSwjURbmhHg+0frD2eI6LIXLK7q+AfOXJiRsEf+0=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=AZXRUIoOxFlIkiHpdUhFuSWivW/N8wWEOAiydquikbSOEboX+k4kdTOZMXT6vj09BxxOK6ogfJHJUevddiLjHaHhY5tBwl2Bj5ksszItegQxdtC1M6a+tjelDHNOPjHy28n5nY75Oobc16T/crRYpu8jaXtzP54ubyVtdwHPrZ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=RcDwMYTW; 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="RcDwMYTW" 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 Reply-To: sashiko-reviews@lists.linux.dev 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> Precedence: bulk X-Mailing-List: linux-s390@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/20260917-b4-mmap-pr= epare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org?part=3D38