From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ross Zwisler Subject: Re: [PATCH v2 0/6] kaddr and pfn can be NULL to ->direct_access() Date: Wed, 25 Jul 2018 11:23:16 -0600 Message-ID: <20180725172316.GA12896@linux.intel.com> References: <20180725162849.8320-1-yehs2007@zoho.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20180725162849.8320-1-yehs2007-ytc+IHgoah0@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Huaisheng Ye Cc: jack-AlSwsSmVLrQ@public.gmane.org, snitzer-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, heiko.carstens-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, agk-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, linux-s390-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, willy-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, bart.vanassche-Sjgp3cTcYWE@public.gmane.org, chengnt-6jq1YtArVR3QT0dZR+AlfA@public.gmane.org, colyli-l3A5Bk7waGM@public.gmane.org, schwidefsky-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org, viro-RmSDqhL/yNMiFSDQTTA3OLVCufUGDwFn@public.gmane.org, axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org, gregkh-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: dm-devel.ids On Thu, Jul 26, 2018 at 12:28:43AM +0800, 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. Looks good. For the series: Reviewed-by: Ross Zwisler