Re: [PATCH V2] bnvdimm/namsepace: Don't set claim_class on error

From: Dan Williams <dan.j.williams@intel.com>
To: "Weiny, Ira" <ira.weiny@intel.com>
Cc: kernel-janitors@vger.kernel.org,
	linux-nvdimm <linux-nvdimm@lists.01.org>
Subject: Re: [PATCH V2] bnvdimm/namsepace: Don't set claim_class on error
Date: Wed, 25 Sep 2019 12:36:35 -0700	[thread overview]
Message-ID: <CAPcyv4jtYxggf-+ZvO5PN3KTMjiqqJrpj_V39_9axJZNpG_EQg@mail.gmail.com> (raw)
In-Reply-To: <20190925184852.11707-1-ira.weiny@intel.com>

On Wed, Sep 25, 2019 at 11:49 AM <ira.weiny@intel.com> wrote:
>
> From: Ira Weiny <ira.weiny@intel.com>
>
> Don't leave claim_class set to an invalid value if an error occurs in
> btt_claim_class().
>
> While we are here change the return type of __holder_class_store() to be
> clear about the values it is returning.
>
> This was found via code inspection.
>
> Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
>
> ---
> V1->V2
>         Add space after variable declaration...

Oh, was also hoping this would address s/bnvdimm/libnvdimm/ in the
patch subject.

Note, kernel-janitors is for minor spelling fixes and trivial changes
with no runtime side-effects that might otherwise fall through the
cracks. This has functional implications so is not a janitorial
change.

One more comment below...

>
>  drivers/nvdimm/namespace_devs.c | 20 ++++++++++----------
>  1 file changed, 10 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
> index 5b22cecefc99..eef885c59f47 100644
> --- a/drivers/nvdimm/namespace_devs.c
> +++ b/drivers/nvdimm/namespace_devs.c
> @@ -1510,16 +1510,20 @@ static ssize_t holder_show(struct device *dev,
>  }
>  static DEVICE_ATTR_RO(holder);
>
> -static ssize_t __holder_class_store(struct device *dev, const char *buf)
> +static int __holder_class_store(struct device *dev, const char *buf)
>  {
>         struct nd_namespace_common *ndns = to_ndns(dev);
>
>         if (dev->driver || ndns->claim)
>                 return -EBUSY;
>
> -       if (sysfs_streq(buf, "btt"))
> -               ndns->claim_class = btt_claim_class(dev);
> -       else if (sysfs_streq(buf, "pfn"))
> +       if (sysfs_streq(buf, "btt")) {
> +               int rc = btt_claim_class(dev);
> +
> +               if (rc < NVDIMM_CCLASS_NONE)
> +                       return rc;
> +               ndns->claim_class = rc;
> +       } else if (sysfs_streq(buf, "pfn"))
>                 ndns->claim_class = NVDIMM_CCLASS_PFN;
>         else if (sysfs_streq(buf, "dax"))
>                 ndns->claim_class = NVDIMM_CCLASS_DAX;
> @@ -1528,10 +1532,6 @@ static ssize_t __holder_class_store(struct device *dev, const char *buf)
>         else
>                 return -EINVAL;
>
> -       /* btt_claim_class() could've returned an error */
> -       if ((int)ndns->claim_class < 0)
> -               return ndns->claim_class;
> -

Since this effectively replaces Dan's patch can you respin without
that baseline, and just give Dan credit with a Reported-by?

>         return 0;
>  }
>
> @@ -1539,7 +1539,7 @@ static ssize_t holder_class_store(struct device *dev,
>                 struct device_attribute *attr, const char *buf, size_t len)
>  {
>         struct nd_region *nd_region = to_nd_region(dev->parent);
> -       ssize_t rc;
> +       int rc;
>
>         nd_device_lock(dev);
>         nvdimm_bus_lock(dev);
> @@ -1547,7 +1547,7 @@ static ssize_t holder_class_store(struct device *dev,
>         rc = __holder_class_store(dev, buf);
>         if (rc >= 0)
>                 rc = nd_namespace_label_update(nd_region, dev);
> -       dev_dbg(dev, "%s(%zd)\n", rc < 0 ? "fail " : "", rc);
> +       dev_dbg(dev, "%s(%d)\n", rc < 0 ? "fail " : "", rc);
>         nvdimm_bus_unlock(dev);
>         nd_device_unlock(dev);
>
> --
> 2.20.1
>
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