Messages in this thread Patch in this message | | | From | Huaisheng Ye <> | Subject | [PATCH 2/3] drivers/s390/block/dcssblk: check the validity of the pointer pfn | Date | Wed, 4 Jul 2018 14:40:57 +0800 |
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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
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