From: Huaisheng Ye <yehs2007@zoho.com>
To: linux-nvdimm@lists.01.org
Cc: dan.j.williams@intel.com, ross.zwisler@linux.intel.com,
mawilcox@microsoft.com, 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.com, chengnt@lenovo.com, linux-kernel@vger.kernel.org,
linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org,
Huaisheng Ye <yehs1@lenovo.com>
Subject: [PATCH 2/3] drivers/s390/block/dcssblk: check the validity of the pointer pfn
Date: Wed, 4 Jul 2018 14:40:57 +0800 [thread overview]
Message-ID: <20180704064058.1344-2-yehs2007@zoho.com> (raw)
In-Reply-To: <20180704064058.1344-1-yehs2007@zoho.com>
From: Huaisheng Ye <yehs1@lenovo.com>
Some functions within fs/dax don't need to get gfn from direct_access.
Assigning NULL to gfn of dax_direct_access is more intuitive and simple
than offering a useless local variable.
So direct_access needs to check validity of the pointer pfn For NULL
assignment. If pfn equals to NULL, it doesn't need to calculate its
value.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
---
drivers/s390/block/dcssblk.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c
index 0a312e4..5cdfa02 100644
--- a/drivers/s390/block/dcssblk.c
+++ b/drivers/s390/block/dcssblk.c
@@ -916,7 +916,8 @@ static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show,
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),
+ 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
next prev parent reply other threads:[~2018-07-04 6:40 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-04 6:40 [PATCH 1/3] nvdimm/pmem: check the validity of the pointer pfn Huaisheng Ye
2018-07-04 6:40 ` Huaisheng Ye [this message]
2018-07-04 6:40 ` [PATCH 3/3] fs/dax: Assigning NULL to gfn of dax_direct_access if useless Huaisheng Ye
2018-07-04 11:30 ` Jan Kara
2018-07-04 13:07 ` Huaisheng Ye
2018-07-04 14:37 ` Dan Williams
2018-07-04 14:41 ` Dan Williams
2018-07-04 15:35 ` [External] " Huaisheng HS1 Ye
2018-07-04 14:40 ` [PATCH 1/3] nvdimm/pmem: check the validity of the pointer pfn Dan Williams
2018-07-04 15:35 ` [External] " Huaisheng HS1 Ye
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