From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 037/118] mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() Date: Thu, 30 Jan 2020 22:13:05 -0800 Message-ID: <20200131061305.O7a_f03M2%akpm@linux-foundation.org> References: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail.kernel.org ([198.145.29.99]:60670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727941AbgAaGNH (ORCPT ); Fri, 31 Jan 2020 01:13:07 -0500 In-Reply-To: <20200130221021.5f0211c56346d5485af07923@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, alex.williamson@redhat.com, aneesh.kumar@linux.ibm.com, axboe@kernel.dk, bjorn.topel@intel.com, corbet@lwn.net, dan.j.williams@intel.com, daniel.vetter@ffwll.ch, hch@lst.de, hverkuil-cisco@xs4all.nl, ira.weiny@intel.com, jack@suse.cz, jgg@mellanox.com, jgg@ziepe.ca, jglisse@redhat.com, jhubbard@nvidia.com, kirill@shutemov.name, leonro@mellanox.com, linux-mm@kvack.org, mchehab@kernel.org, mm-commits@vger.kernel.org, rppt@linux.ibm.com, torvalds@linux-foundation.org =46rom: John Hubbard Subject: mm/process_vm_access: set FOLL_PIN via pin_user_pages_remote() Convert process_vm_access to use the new pin_user_pages_remote() call, which sets FOLL_PIN. Setting FOLL_PIN is now required for code that requires tracking of pinned pages. Also, release the pages via put_user_page*(). Also, rename "pages" to "pinned_pages", as this makes for easier reading of process_vm_rw_single_vec(). Link: http://lkml.kernel.org/r/20200107224558.2362728-15-jhubbard@nvidia.com Signed-off-by: John Hubbard Reviewed-by: Jan Kara Reviewed-by: J=C3=A9r=C3=B4me Glisse Reviewed-by: Ira Weiny Cc: Alex Williamson Cc: Aneesh Kumar K.V Cc: Bj=C3=B6rn T=C3=B6pel Cc: Christoph Hellwig Cc: Daniel Vetter Cc: Dan Williams Cc: Hans Verkuil Cc: Jason Gunthorpe Cc: Jason Gunthorpe Cc: Jens Axboe Cc: Jonathan Corbet Cc: Kirill A. Shutemov Cc: Leon Romanovsky Cc: Mauro Carvalho Chehab Cc: Mike Rapoport Signed-off-by: Andrew Morton --- mm/process_vm_access.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) --- a/mm/process_vm_access.c~mm-process_vm_access-set-foll_pin-via-pin_user= _pages_remote +++ a/mm/process_vm_access.c @@ -42,12 +42,11 @@ static int process_vm_rw_pages(struct pa if (copy > len) copy =3D len; =20 - if (vm_write) { + if (vm_write) copied =3D copy_page_from_iter(page, offset, copy, iter); - set_page_dirty_lock(page); - } else { + else copied =3D copy_page_to_iter(page, offset, copy, iter); - } + len -=3D copied; if (copied < copy && iov_iter_count(iter)) return -EFAULT; @@ -96,7 +95,7 @@ static int process_vm_rw_single_vec(unsi flags |=3D FOLL_WRITE; =20 while (!rc && nr_pages && iov_iter_count(iter)) { - int pages =3D min(nr_pages, max_pages_per_loop); + int pinned_pages =3D min(nr_pages, max_pages_per_loop); int locked =3D 1; size_t bytes; =20 @@ -106,14 +105,15 @@ static int process_vm_rw_single_vec(unsi * current/current->mm */ down_read(&mm->mmap_sem); - pages =3D get_user_pages_remote(task, mm, pa, pages, flags, - process_pages, NULL, &locked); + pinned_pages =3D pin_user_pages_remote(task, mm, pa, pinned_pages, + flags, process_pages, + NULL, &locked); if (locked) up_read(&mm->mmap_sem); - if (pages <=3D 0) + if (pinned_pages <=3D 0) return -EFAULT; =20 - bytes =3D pages * PAGE_SIZE - start_offset; + bytes =3D pinned_pages * PAGE_SIZE - start_offset; if (bytes > len) bytes =3D len; =20 @@ -122,10 +122,12 @@ static int process_vm_rw_single_vec(unsi vm_write); len -=3D bytes; start_offset =3D 0; - nr_pages -=3D pages; - pa +=3D pages * PAGE_SIZE; - while (pages) - put_page(process_pages[--pages]); + nr_pages -=3D pinned_pages; + pa +=3D pinned_pages * PAGE_SIZE; + + /* If vm_write is set, the pages need to be made dirty: */ + put_user_pages_dirty_lock(process_pages, pinned_pages, + vm_write); } =20 return rc; _