From patchwork Wed Jul 25 16:28:43 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Huaisheng Ye X-Patchwork-Id: 10544315 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 5DFB914E2 for ; Wed, 25 Jul 2018 16:29:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4BB3D2A6F0 for ; Wed, 25 Jul 2018 16:29:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3F7A42A6F2; Wed, 25 Jul 2018 16:29:36 +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=-2.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3E5752A6F0 for ; Wed, 25 Jul 2018 16:29:35 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id E78CC210C1EFC; Wed, 25 Jul 2018 09:29:34 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=135.84.80.237; helo=sender-pp-092.zoho.com; envelope-from=yehs2007@zoho.com; receiver=linux-nvdimm@lists.01.org Received: from sender-pp-092.zoho.com (sender-pp-092.zoho.com [135.84.80.237]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 24ABC2097FABE for ; Wed, 25 Jul 2018 09:29:33 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=from:to:cc:subject:date:message-id; b=aV/9QE9mzcksi9RQ982PkR6fOWTxeBmZRa5EG9AlJVRnenjEcIc8DtWb4pI3+TBdf3RoMYIkfu9U n0zjz2A81S23QBJY5as9RFwLMMbxqPru+BKLLuNPglPWzzPqO5PK Received: from YEHS1XR956R00D1.lenovo.com (114.245.13.10 [114.245.13.10]) by mx.zohomail.com with SMTPS id 15325361439801006.2989965103092; Wed, 25 Jul 2018 09:29:03 -0700 (PDT) From: Huaisheng Ye To: linux-nvdimm@lists.01.org, dan.j.williams@intel.com Subject: [PATCH v2 0/6] kaddr and pfn can be NULL to ->direct_access() Date: Thu, 26 Jul 2018 00:28:43 +0800 Message-Id: <20180725162849.8320-1-yehs2007@zoho.com> X-Mailer: git-send-email 2.17.0.windows.1 X-ZohoMailClient: External X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: axboe@kernel.dk, linux-s390@vger.kernel.org, snitzer@redhat.com, chengnt@lenovo.com, linux-fsdevel@vger.kernel.org, heiko.carstens@de.ibm.com, linux-kernel@vger.kernel.org, willy@infradead.org, colyli@suse.de, bart.vanassche@wdc.com, dm-devel@redhat.com, viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org, schwidefsky@de.ibm.com, jack@suse.cz, agk@redhat.com MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP From: Huaisheng Ye 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 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 to ->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(-) Reviewed-by: Ross Zwisler