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 85402C88E72 for ; Thu, 17 Sep 2026 17:34:07 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AACB410F024; Thu, 17 Sep 2026 17:34:06 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="PqA1D2eh"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5315F10F024 for ; Thu, 17 Sep 2026 17:34:05 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 8DB0360202; Thu, 17 Sep 2026 17:34:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6EF271F000FF; Thu, 17 Sep 2026 17:34:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789666444; bh=KGbqyAT/TiyJlIwP5C3BkJDelZU3+k7lsVP6/O1KyOE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=PqA1D2eh0vHM1w8JZn/OuKCp74Gg4monMIroiEMvP9+fzXFO12JDc+uNqws1yXzgS KMHjR/pOJ2FQ3mWm2zbbsSKGqL1ZwPyBw2fQCXWtAw3Bx/C1qddRj6exthcfjxaBgM 89J1ScbIeF8qj3/msWk4R2yvf7geoyXs5lSYTom3lULrLHWlg7Ev5CxsJgp+nNIUT8 JoTktDGaX7MjFcW1t8uYvCyX3SHgHB0mY97JSGS6QL44Cy+t0N0LQFwweaCK7x/oH9 0ZsiTFBZdhTHF25R+YMdupe0+LcV6XVuY9Qdv4vxjb/9+zCFF+3L7BQSB2GRPUnSEf 0Eu1MRX9fKshA== From: sashiko-bot@kernel.org Subject: Re: [PATCH v3 18/40] scsi: sg: convert mmap hook to mmap_prepare and rework To: =?utf-8?b?TG9yZW56byBTdG9ha2VzIChBUk0p?= Cc: "Marc Zyngier" , linux-perf-users@vger.kernel.org, "Heiko Carstens" , kvm@vger.kernel.org, linux-s390@vger.kernel.org, "Alexander Gordeev" , linux-rdma@vger.kernel.org, linux-scsi@vger.kernel.org, "Christian Borntraeger" , "Oliver Upton" , selinux@vger.kernel.org, "Vasily Gorbik" , linux-trace-kernel@vger.kernel.org, kvmarm@lists.linux.dev, dri-devel@lists.freedesktop.org, bpf@vger.kernel.org In-Reply-To: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-18-4583d8a23bca@kernel.org> References: <20260917-b4-mmap-prepare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org> <20260917-b4-mmap-prepare-vma-flag-sanify-v3-18-4583d8a23bca@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 17 Sep 2026 17:34:02 +0000 Message-Id: <20260917173403.6EF271F000FF@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" > 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/20260917-b4-mmap-pr= epare-vma-flag-sanify-v3-0-4583d8a23bca@kernel.org?part=3D18