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 X-Spam-Level: X-Spam-Status: No, score=-3.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5A70C46461 for ; Mon, 30 Jul 2018 07:16:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7DE2220892 for ; Mon, 30 Jul 2018 07:16:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DE2220892 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zoho.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726962AbeG3IuR (ORCPT ); Mon, 30 Jul 2018 04:50:17 -0400 Received: from sender-pp-092.zoho.com ([135.84.80.237]:25482 "EHLO sender-pp-092.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726210AbeG3IuR (ORCPT ); Mon, 30 Jul 2018 04:50:17 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=from:to:cc:subject:date:message-id; b=knHOh6YvevoSp9xI3qCJCtl+umkguSzLO38fhTaOsVIaaivoM65fYFGOaEb/3jX6epaTHa5+t2Rn 6pJgDNTcOlxLfaRHAsUfbojLQWn1VDefmflXJ5h06FMgJMLz/oZ9 Received: from YEHS1XR956R00D1.lenovo.com (221.219.122.69 [221.219.122.69]) by mx.zohomail.com with SMTPS id 1532934965421456.2684745169777; Mon, 30 Jul 2018 00:16:05 -0700 (PDT) From: Huaisheng Ye To: linux-nvdimm@lists.01.org, dan.j.williams@intel.com Cc: ross.zwisler@linux.intel.com, willy@infradead.org, vishal.l.verma@intel.com, dave.jiang@intel.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, viro@zeniv.linux.org.uk, martin.petersen@oracle.com, axboe@kernel.dk, gregkh@linuxfoundation.org, bart.vanassche@wdc.com, jack@suse.cz, agk@redhat.com, snitzer@redhat.com, keescook@chromium.org, dm-devel@redhat.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, colyli@suse.de, chengnt@lenovo.com, Huaisheng Ye Subject: [PATCH v3 0/6] kaddr and pfn can be NULL to ->direct_access() Date: Mon, 30 Jul 2018 15:15:42 +0800 Message-Id: <20180730071548.9172-1-yehs2007@zoho.com> X-Mailer: git-send-email 2.17.0.windows.1 X-ZohoMailClient: External Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huaisheng Ye Changes since v2 [2]: * Collect Martin and Mike's acks for dcssblk and dm-writecache; * Rebase the series of patch to v4.18-rc7. Changes since v1 [1]: * Involve the previous patches for pfn can be NULL. * Reword the patch descriptions according to Christian's comment. * According to Ross's suggestion, replace local pointer dummy_addr with NULL within md/dm-writecache for direct_access. [1]: https://lkml.org/lkml/2018/7/24/199 [2]: https://lkml.org/lkml/2018/7/25/581 Some functions within fs/dax, dax/super and md/dm-writecache don't need to get local pointer kaddr or variable pfn from direct_access. Assigning NULL to kaddr or pfn with ->direct_access() is more straightforward and simple than offering a useless local pointer or variable. So all ->direct_access() need to check the validity of pointer kaddr and pfn for NULL assignment. If either of them is equal to NULL, that is to say callers may have no need for kaddr or pfn, so this series of patch are prepared for allowing them to pass in NULL instead of having to pass in a local pointer or variable that they then just throw away. Huaisheng Ye (6): libnvdimm, pmem: kaddr and pfn can be NULL to ->direct_access() s390, dcssblk: kaddr and pfn can be NULL to ->direct_access() tools/testing/nvdimm: kaddr and pfn can be NULL to ->direct_access() dax/super: Do not request a pointer kaddr when not required md/dm-writecache: Don't request pointer dummy_addr when not required filesystem-dax: Do not request kaddr and pfn when not required drivers/dax/super.c | 3 +-- drivers/md/dm-writecache.c | 3 +-- drivers/nvdimm/pmem.c | 7 +++++-- drivers/s390/block/dcssblk.c | 8 +++++--- fs/dax.c | 13 ++++--------- tools/testing/nvdimm/pmem-dax.c | 12 ++++++++---- 6 files changed, 24 insertions(+), 22 deletions(-) -- 1.8.3.1