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 739773B42CD; Mon, 14 Sep 2026 19:30:41 +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=1789414245; cv=none; b=WNNqeMRL8MtdVJgZgPD46AIUtb8dAEBOx7Y8jiW3m8hZ8cI6RGj/A+3w/NSxx+1jBEGNli8V0fJM/qWr19eyLtokqTe2p3bp1X8UAWZ13HoEndYLXsd3Kt47qKXxGn/J7IFKZYAL1dTAZV3C8KQK4pp2PMdvhhXU0zmNpBa4yFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789414245; c=relaxed/simple; bh=RYNo57I33B8B6G5soVxuM2FDSfkKyXuqNa0URMDrOrw=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=rxXzi2QjcAhOXowb7R1ZXC7V3uUYjAEO/SQ/gZaIjkXxDVeHaHrMmfrBxRmgUoh6YCrA/QqtiE0cb4M94W74QzlVhxjg5MHNngOV0WkjagHhItKJ2M5jE8UwxzrRShcsCa7G9x6rwRS62Y2pswA/d5sG6AEe1xo6kMnpTWgMCI4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ocgFENtc; 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="ocgFENtc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 881811F000FF; Mon, 14 Sep 2026 19:30:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789414239; bh=RYNo57I33B8B6G5soVxuM2FDSfkKyXuqNa0URMDrOrw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=ocgFENtctck8/1LbDx7qCHTjPJ8FC73vxB9khKkNOtsqgHkgvq3Mml61t65Up4Zi7 wXU051uwgpTe1OMCEuXBN6NBnRmtUkoyqA2YiMgo+BGph9D9iGwMzglpKhNwF89yzj 2jjomdD5T1OSV/hykxQ6mTf67G2GskZn9TQUXTjK0PH6/qmlhsuj3iWx05fzHeYeu3 OauKBH+R04LfMgpon0PDXpkJmrfYsHUjfUt4IAjHJMnXJ5FJTr9pzSAe61EGjW+zD9 XdEs5riJHkjHYzFBDjrb1E9BfuVkeDdJzD1qi8T3RZJDOtOi+uVUFo9VH+B3dw8sTB zodEj/VSqMUfQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 18/40] scsi: sg: convert mmap hook to mmap_prepare and rework Reply-To: sashiko-reviews@lists.linux.dev To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Oliver Upton" , kvm@vger.kernel.org, linux-rdma@vger.kernel.org, "Heiko Carstens" , "Christian Borntraeger" , linux-scsi@vger.kernel.org, dri-devel@lists.freedesktop.org, kvmarm@lists.linux.dev, "Marc Zyngier" , "Alexander Gordeev" , linux-s390@vger.kernel.org, linux-perf-users@vger.kernel.org, "Vasily Gorbik" , selinux@vger.kernel.org, linux-trace-kernel@vger.kernel.org, bpf@vger.kernel.org In-Reply-To: <20260914-b4-mmap-prepare-vma-flag-sanify-v2-18-7d9781ed5361@kernel.org> References: <20260914-b4-mmap-prepare-vma-flag-sanify-v2-0-7d9781ed5361@kernel.org> <20260914-b4-mmap-prepare-vma-flag-sanify-v2-18-7d9781ed5361@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 14 Sep 2026 19:30:38 +0000 Message-Id: <20260914193038.881811F000FF@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Move from the deprecated mmap hook to the new mmap_prepare hook. >=20 > We are mapping kernel pages here, so use the discontiguous kernel mapping > mmap action to do so. >=20 > Unwind the rather confusing loop and instead map as many pages as we can = at > one time. >=20 > Note that we do not need to pay attention to rsv_schp->k_use_sg here, as > the pages are populated for the length of the buffer at > rsv_schp->page_order granularity as compound pages. >=20 > The discontiguous kernel page mapping logic handles the compound pages for > us. >=20 > sfp->mmap_called keeps the buffer stable for us. As before it is never > cleared, so a failed mmap also leaves it set. >=20 > We also remove some useless vma, vma->vm_file NULL checks - these will > always be non-NULL if you reached the mmap hook logic. >=20 > We retain log output for consistency, but change what's output on page > mapping to indicate that sg_discontig_get() does the work now. >=20 > Note that we drop the VMA_IO_BIT flag for the VMA here. It was never > necessary as we invoke alloc_pages() which gives us refcounted folios that > are fine for GUP to access (VMA_IO_BIT would prevent that). >=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/20260914-b4-mmap-pr= epare-vma-flag-sanify-v2-0-7d9781ed5361@kernel.org?part=3D18