On 11/8/24 1:55 AM, Yi Yang wrote:
> When nd_dax is NULL, nd_pfn is consequently NULL as well. Nevertheless,
> it is inadvisable to perform pointer arithmetic or address-taking on a
> NULL pointer.
> Introduce the nd_dax_devinit() function to enhance the code's logic and
> improve its readability.
>
> Signed-off-by: Yi Yang <yiyan...@huawei.com>
Reviewed-by: Dave Jiang <dave.ji...@intel.com>
but a few comments for future patches:
Is this v2 of the patch? Please label patch subject prefix as so.
> ---
Please include change history here from previous versions.
> drivers/nvdimm/dax_devs.c | 4 ++--
> drivers/nvdimm/nd.h | 7 +++++++
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
> index 6b4922de3047..37b743acbb7b 100644
> --- a/drivers/nvdimm/dax_devs.c
> +++ b/drivers/nvdimm/dax_devs.c
> @@ -106,12 +106,12 @@ int nd_dax_probe(struct device *dev, struct
> nd_namespace_common *ndns)
>
> nvdimm_bus_lock(&ndns->dev);
> nd_dax = nd_dax_alloc(nd_region);
> - nd_pfn = &nd_dax->nd_pfn;
> - dax_dev = nd_pfn_devinit(nd_pfn, ndns);
> + dax_dev = nd_dax_devinit(nd_dax, ndns);
> nvdimm_bus_unlock(&ndns->dev);
> if (!dax_dev)
> return -ENOMEM;
> pfn_sb = devm_kmalloc(dev, sizeof(*pfn_sb), GFP_KERNEL);
> + nd_pfn = &nd_dax->nd_pfn;
> nd_pfn->pfn_sb = pfn_sb;
> rc = nd_pfn_validate(nd_pfn, DAX_SIG);
> dev_dbg(dev, "dax: %s\n", rc == 0 ? dev_name(dax_dev) : "<none>");
> diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
> index 2dbb1dca17b5..5ca06e9a2d29 100644
> --- a/drivers/nvdimm/nd.h
> +++ b/drivers/nvdimm/nd.h
> @@ -600,6 +600,13 @@ struct nd_dax *to_nd_dax(struct device *dev);
> int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns);
> bool is_nd_dax(const struct device *dev);
> struct device *nd_dax_create(struct nd_region *nd_region);
> +static inline struct device *nd_dax_devinit(struct nd_dax *nd_dax,
> + struct nd_namespace_common *ndns)
> +{
> + if (!nd_dax)
> + return NULL;
> + return nd_pfn_devinit(&nd_dax->nd_pfn, ndns);
> +}
> #else
> static inline int nd_dax_probe(struct device *dev,
> struct nd_namespace_common *ndns)
