From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id E3ABE207DF29B for ; Wed, 25 Jul 2018 14:35:55 -0700 (PDT) Subject: Re: [PATCH v2 0/6] kaddr and pfn can be NULL to ->direct_access() References: <20180725162849.8320-1-yehs2007@zoho.com> From: Dave Jiang Message-ID: <3689520a-4a49-4e1f-6ee9-2ff4a9796b9f@intel.com> Date: Wed, 25 Jul 2018 14:35:32 -0700 MIME-Version: 1.0 In-Reply-To: <20180725162849.8320-1-yehs2007@zoho.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Huaisheng Ye , linux-nvdimm@lists.01.org, dan.j.williams@intel.com Cc: axboe@kernel.dk, linux-s390@vger.kernel.org, jack@suse.cz, snitzer@redhat.com, chengnt@lenovo.com, 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, linux-fsdevel@vger.kernel.org, agk@redhat.com List-ID: Pretty straight forward series. Huaisheng, I can apply the whole series to libnvdimm if we can get ack's from maintainer of dcssblk and dm-writecache for the respective bits. On 07/25/2018 09:28 AM, Huaisheng Ye wrote: > 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(-) > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm