From: Martin Schwidefsky Subject: Re: [External] [PATCH v2 2/6] s390, dcssblk: kaddr and pfn can be NULL to ->direct_access() Date: Mon, 30 Jul 2018 07:14:58 +0200 Message-ID: <20180730071458.42e3c5a1@mschwideX1> References: <20180725162849.8320-1-yehs2007@zoho.com> <20180725162849.8320-3-yehs2007@zoho.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: Huaisheng HS1 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" , "keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org" , NingTing Cheng , "colyli-l3A5Bk7waGM@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 Sat, 28 Jul 2018 04:07:25 +0000 Huaisheng HS1 Ye wrote: > May I have your ack's for this patch? The whole series would be applied > to libnvdimm if it could get your approval. > And any suggestion is welcome. Sure, it is just two additional ifs. I did not think that this needed an ack, but here you go: Acked-by: Martin Schwidefsky > > Cheers, > Huaisheng Ye > > > From: Huaisheng Ye > > Sent: Thursday, July 26, 2018 12:29 AM > > > > From: Huaisheng Ye > > > > dcssblk_direct_access() needs to check the validity of pointers kaddr > > and pfn for NULL assignment. If anyone equals to NULL, it doesn't need > > to calculate the value. > > > > If either of them is equal to NULL, that is to say callers may > > have no need for kaddr or pfn, so this patch is prepared for allowing > > them to pass in NULL instead of having to pass in a pointer or local > > variable that they then just throw away. > > > > Signed-off-by: Huaisheng Ye > > --- > > drivers/s390/block/dcssblk.c | 8 +++++--- > > 1 file changed, 5 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c > > index ed60728..23e526c 100644 > > --- a/drivers/s390/block/dcssblk.c > > +++ b/drivers/s390/block/dcssblk.c > > @@ -922,9 +922,11 @@ static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show, > > unsigned long dev_sz; > > > > dev_sz = dev_info->end - dev_info->start + 1; > > - *kaddr = (void *) dev_info->start + offset; > > - *pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), > > - PFN_DEV|PFN_SPECIAL); > > + if (kaddr) > > + *kaddr = (void *) dev_info->start + offset; > > + if (pfn) > > + *pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), > > + PFN_DEV|PFN_SPECIAL); > > > > return (dev_sz - offset) / PAGE_SIZE; > > } > > -- > > 1.8.3.1 > -- blue skies, Martin. "Reality continues to ruin my life." - Calvin.