From patchwork Wed Feb 13 23:04:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ira Weiny X-Patchwork-Id: 10811259 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7149513B4 for ; Wed, 13 Feb 2019 23:07:03 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5EEFF2DD1D for ; Wed, 13 Feb 2019 23:07:03 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4EB1C2DC70; Wed, 13 Feb 2019 23:07:03 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EB7F82DC70 for ; Wed, 13 Feb 2019 23:07:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392905AbfBMXGs (ORCPT ); Wed, 13 Feb 2019 18:06:48 -0500 Received: from mga05.intel.com ([192.55.52.43]:40570 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392790AbfBMXFc (ORCPT ); Wed, 13 Feb 2019 18:05:32 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Feb 2019 15:05:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.58,366,1544515200"; d="scan'208";a="138415618" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by orsmga001.jf.intel.com with ESMTP; 13 Feb 2019 15:05:24 -0800 From: ira.weiny@intel.com To: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, kvm@vger.kernel.org, linux-fpga@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-scsi@vger.kernel.org, devel@driverdev.osuosl.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-fbdev@vger.kernel.org, xen-devel@lists.xenproject.org, devel@lists.orangefs.org, linux-mm@kvack.org, ceph-devel@vger.kernel.org, rds-devel@oss.oracle.com Cc: Ira Weiny , John Hubbard , David Hildenbrand , Cornelia Huck , Yoshinori Sato , Rich Felker , "David S. Miller" , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Joerg Roedel , Wu Hao , Alan Tull , Moritz Fischer , David Airlie , Daniel Vetter , Jason Gunthorpe , Dennis Dalessandro , Christian Benvenuti , Mauro Carvalho Chehab , Matt Porter , Alexandre Bounine , =?utf-8?q?Kai_M=C3=A4kisara?= , "James E.J. Bottomley" , "Martin K. Petersen" , Rob Springer , Todd Poynor , Ben Chan , Jens Wiklander , Alex Williamson , "Michael S. Tsirkin" , Jason Wang , Bartlomiej Zolnierkiewicz , Stefano Stabellini , Martin Brandenburg , Peter Zijlstra , Alexander Viro , Andrew Morton , Michal Hocko , "Kirill A. Shutemov" Subject: [PATCH V2 4/7] mm/gup: Add FOLL_LONGTERM capability to GUP fast Date: Wed, 13 Feb 2019 15:04:52 -0800 Message-Id: <20190213230455.5605-5-ira.weiny@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190213230455.5605-1-ira.weiny@intel.com> References: <20190211201643.7599-1-ira.weiny@intel.com> <20190213230455.5605-1-ira.weiny@intel.com> MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Ira Weiny DAX pages were previously unprotected from longterm pins when users called get_user_pages_fast(). Use the new FOLL_LONGTERM flag to check for DEVMAP pages and fall back to regular GUP processing if a DEVMAP page is encountered. Signed-off-by: Ira Weiny --- mm/gup.c | 24 +++++++++++++++++++++--- 1 file changed, 21 insertions(+), 3 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 6f32d36b3c5b..f7e759c523bb 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -1439,6 +1439,9 @@ static int gup_pte_range(pmd_t pmd, unsigned long addr, unsigned long end, goto pte_unmap; if (pte_devmap(pte)) { + if (unlikely(flags & FOLL_LONGTERM)) + goto pte_unmap; + pgmap = get_dev_pagemap(pte_pfn(pte), pgmap); if (unlikely(!pgmap)) { undo_dev_pagemap(nr, nr_start, pages); @@ -1578,8 +1581,11 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, if (!pmd_access_permitted(orig, flags & FOLL_WRITE)) return 0; - if (pmd_devmap(orig)) + if (pmd_devmap(orig)) { + if (unlikely(flags & FOLL_LONGTERM)) + return 0; return __gup_device_huge_pmd(orig, pmdp, addr, end, pages, nr); + } refs = 0; page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); @@ -1904,8 +1910,20 @@ int get_user_pages_fast(unsigned long start, int nr_pages, start += nr << PAGE_SHIFT; pages += nr; - ret = get_user_pages_unlocked(start, nr_pages - nr, pages, - gup_flags); + if (gup_flags & FOLL_LONGTERM) { + down_read(¤t->mm->mmap_sem); + ret = __gup_longterm_locked(current, current->mm, + start, nr_pages - nr, + pages, NULL, gup_flags); + up_read(¤t->mm->mmap_sem); + } else { + /* + * retain FAULT_FOLL_ALLOW_RETRY optimization if + * possible + */ + ret = get_user_pages_unlocked(start, nr_pages - nr, + pages, gup_flags); + } /* Have to be a bit careful with return values */ if (nr > 0) {