[PATCH V3] libnvdimm/namsepace: Don't set claim_class on error

[PATCH V3] libnvdimm/namsepace: Don't set claim_class on error

[ira.weiny]

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.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
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...

V2->V3
	Fix oneliner
	Rebase without Dan Carpenter's patch and give him Reported-by
		credit

 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 a16e52251a30..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 (ndns->claim_class < 0)
-		return ndns->claim_class;
-
 	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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Re: [PATCH V3] libnvdimm/namsepace: Don't set claim_class on error

[Dan Carpenter]

On Wed, Sep 25, 2019 at 02:13:48PM -0700, 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.
> 
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> 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...
> 
> V2->V3
> 	Fix oneliner
> 	Rebase without Dan Carpenter's patch and give him Reported-by
> 		credit

Thanks!  Btw, if it's ever a question of "do you want to redo a patch or
just transfer to reported by credit?" then always I always want the #2
option.  It would have taken me several iterations to generate the patch
you wanted.

regards,
dan carpenter

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Re: [PATCH V3] libnvdimm/namsepace: Don't set claim_class on error

[Ira Weiny]

On Thu, Sep 26, 2019 at 09:12:57AM +0300, Dan Carpenter wrote:
> On Wed, Sep 25, 2019 at 02:13:48PM -0700, 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.
> > 
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 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...
> > 
> > V2->V3
> > 	Fix oneliner
> > 	Rebase without Dan Carpenter's patch and give him Reported-by
> > 		credit
> 
> Thanks!  Btw, if it's ever a question of "do you want to redo a patch or
> just transfer to reported by credit?" then always I always want the #2
> option.  It would have taken me several iterations to generate the patch
> you wanted.

Thanks for letting me know!

And thanks for finding this as well.  :-D

Ira

> 
> regards,
> dan carpenter
> 
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