[PATCH] libnvdimm: Fix nvdimm_probe error on NVDIMM-N

[PATCH] libnvdimm: Fix nvdimm_probe error on NVDIMM-N

[Toshi Kani]

'ndctl list --buses --dimms' does not list any NVDIMM-Ns since
they are considered as idle.  ndctl checks if any driver is
attached to nmem device.  nvdimm_probe() always fails in
nvdimm_init_nsarea() since NVDIMM-Ns do not implement optinal
ND_CMD_GET_CONFIG_DATA command.

Change nvdimm_probe() to accept the case that the CONFIG_DATA
command is not implemented for NVDIMM-Ns.  The driver attaches
without ndd, which keeps it no-op to the device.

Reported-by: Brian Boylston <brian.boylston@hpe.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
---
 drivers/nvdimm/dimm.c      |   10 ++++++++++
 drivers/nvdimm/dimm_devs.c |   27 ++++++++++++++++-----------
 drivers/nvdimm/nd.h        |    1 +
 3 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/drivers/nvdimm/dimm.c b/drivers/nvdimm/dimm.c
index 71d12bb..07e09c2 100644
--- a/drivers/nvdimm/dimm.c
+++ b/drivers/nvdimm/dimm.c
@@ -26,6 +26,13 @@ static int nvdimm_probe(struct device *dev)
 	struct nvdimm_drvdata *ndd;
 	int rc;
 
+	rc = nvdimm_check_config_data(dev);
+	if (rc == -ENOENT)
+		/* not required for non-aliased nvdimm, ex. NVDIMM-N */
+		return 0;
+	else
+		return rc;
+
 	ndd = kzalloc(sizeof(*ndd), GFP_KERNEL);
 	if (!ndd)
 		return -ENOMEM;
@@ -72,6 +79,9 @@ static int nvdimm_remove(struct device *dev)
 {
 	struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
 
+	if (!ndd)
+		return 0;
+
 	nvdimm_bus_lock(dev);
 	dev_set_drvdata(dev, NULL);
 	nvdimm_bus_unlock(dev);
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index d9bba5e..fee82d3 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -28,28 +28,33 @@ static DEFINE_IDA(dimm_ida);
  * Retrieve bus and dimm handle and return if this bus supports
  * get_config_data commands
  */
-static int __validate_dimm(struct nvdimm_drvdata *ndd)
+int nvdimm_check_config_data(struct device *dev)
 {
-	struct nvdimm *nvdimm;
-
-	if (!ndd)
-		return -EINVAL;
-
-	nvdimm = to_nvdimm(ndd->dev);
+	struct nvdimm *nvdimm = to_nvdimm(dev);
 
 	if (!nvdimm->cmd_mask)
-		return -ENXIO;
+		goto err;
 	if (!test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask))
-		return -ENXIO;
+		goto err;
 
 	return 0;
+
+ err:
+	if (nvdimm->flags & NDD_ALIASING)
+		return -ENXIO;
+	else
+		return -ENOENT;
 }
 
 static int validate_dimm(struct nvdimm_drvdata *ndd)
 {
-	int rc = __validate_dimm(ndd);
+	int rc;
 
-	if (rc && ndd)
+	if (!ndd)
+		return -EINVAL;
+
+	rc = nvdimm_check_config_data(ndd->dev);
+	if (rc)
 		dev_dbg(ndd->dev, "%pf: %s error: %d\n",
 				__builtin_return_address(0), __func__, rc);
 	return rc;
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 8024a0e..38d6f03 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -191,6 +191,7 @@ void nvdimm_exit(void);
 void nd_region_exit(void);
 struct nvdimm;
 struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping);
+int nvdimm_check_config_data(struct device *dev);
 int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd);
 int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
 int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,

Re: [PATCH] libnvdimm: Fix nvdimm_probe error on NVDIMM-N

[Dan Williams]

On Mon, Aug 15, 2016 at 10:52 AM, Toshi Kani <toshi.kani@hpe.com> wrote:
> 'ndctl list --buses --dimms' does not list any NVDIMM-Ns since
> they are considered as idle.  ndctl checks if any driver is
> attached to nmem device.  nvdimm_probe() always fails in
> nvdimm_init_nsarea() since NVDIMM-Ns do not implement optinal
> ND_CMD_GET_CONFIG_DATA command.
>
> Change nvdimm_probe() to accept the case that the CONFIG_DATA
> command is not implemented for NVDIMM-Ns.  The driver attaches
> without ndd, which keeps it no-op to the device.
>
> Reported-by: Brian Boylston <brian.boylston@hpe.com>
> Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
> Cc: Dan Williams <dan.j.williams@intel.com>
> ---
>  drivers/nvdimm/dimm.c      |   10 ++++++++++
>  drivers/nvdimm/dimm_devs.c |   27 ++++++++++++++++-----------
>  drivers/nvdimm/nd.h        |    1 +
>  3 files changed, 27 insertions(+), 11 deletions(-)

This fails the ndctl unit test suite, see below plus some other cleanups...

>
> diff --git a/drivers/nvdimm/dimm.c b/drivers/nvdimm/dimm.c
> index 71d12bb..07e09c2 100644
> --- a/drivers/nvdimm/dimm.c
> +++ b/drivers/nvdimm/dimm.c
> @@ -26,6 +26,13 @@ static int nvdimm_probe(struct device *dev)
>         struct nvdimm_drvdata *ndd;
>         int rc;
>
> +       rc = nvdimm_check_config_data(dev);
> +       if (rc == -ENOENT)
> +               /* not required for non-aliased nvdimm, ex. NVDIMM-N */
> +               return 0;
> +       else
> +               return rc;
> +

Change usage of ENOENT to ENOTTY throughout...

>         ndd = kzalloc(sizeof(*ndd), GFP_KERNEL);
>         if (!ndd)
>                 return -ENOMEM;
> @@ -72,6 +79,9 @@ static int nvdimm_remove(struct device *dev)
>  {
>         struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
>
> +       if (!ndd)
> +               return 0;
> +
>         nvdimm_bus_lock(dev);
>         dev_set_drvdata(dev, NULL);
>         nvdimm_bus_unlock(dev);
> diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
> index d9bba5e..fee82d3 100644
> --- a/drivers/nvdimm/dimm_devs.c
> +++ b/drivers/nvdimm/dimm_devs.c
> @@ -28,28 +28,33 @@ static DEFINE_IDA(dimm_ida);
>   * Retrieve bus and dimm handle and return if this bus supports
>   * get_config_data commands
>   */
> -static int __validate_dimm(struct nvdimm_drvdata *ndd)
> +int nvdimm_check_config_data(struct device *dev)
>  {
> -       struct nvdimm *nvdimm;
> -
> -       if (!ndd)
> -               return -EINVAL;
> -
> -       nvdimm = to_nvdimm(ndd->dev);
> +       struct nvdimm *nvdimm = to_nvdimm(dev);
>
>         if (!nvdimm->cmd_mask)
> -               return -ENXIO;
> +               goto err;
>         if (!test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask))
> -               return -ENXIO;
> +               goto err;
>
>         return 0;
> +
> + err:
> +       if (nvdimm->flags & NDD_ALIASING)
> +               return -ENXIO;
> +       else
> +               return -ENOENT;


Let's not use "goto" since there is nothing to unwind.


>  }
>
>  static int validate_dimm(struct nvdimm_drvdata *ndd)
>  {
> -       int rc = __validate_dimm(ndd);
> +       int rc;
>
> -       if (rc && ndd)
> +       if (!ndd)
> +               return -EINVAL;

Since we've called nvdimm_check_config_data() before allocating ndd it
will always be NULL causing DIMMs with label areas to fail init.


> +
> +       rc = nvdimm_check_config_data(ndd->dev);
> +       if (rc)
>                 dev_dbg(ndd->dev, "%pf: %s error: %d\n",
>                                 __builtin_return_address(0), __func__, rc);
>         return rc;
> diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
> index 8024a0e..38d6f03 100644
> --- a/drivers/nvdimm/nd.h
> +++ b/drivers/nvdimm/nd.h
> @@ -191,6 +191,7 @@ void nvdimm_exit(void);
>  void nd_region_exit(void);
>  struct nvdimm;
>  struct nvdimm_drvdata *to_ndd(struct nd_mapping *nd_mapping);
> +int nvdimm_check_config_data(struct device *dev);
>  int nvdimm_init_nsarea(struct nvdimm_drvdata *ndd);
>  int nvdimm_init_config_data(struct nvdimm_drvdata *ndd);
>  int nvdimm_set_config_data(struct nvdimm_drvdata *ndd, size_t offset,

Re: [PATCH] libnvdimm: Fix nvdimm_probe error on NVDIMM-N

[Kani, Toshimitsu]

On Mon, 2016-08-15 at 14:20 -0700, Dan Williams wrote:
> On Mon, Aug 15, 2016 at 10:52 AM, Toshi Kani <toshi.kani@hpe.com>
> wrote:
> > 
> > 'ndctl list --buses --dimms' does not list any NVDIMM-Ns since
> > they are considered as idle.  ndctl checks if any driver is
> > attached to nmem device.  nvdimm_probe() always fails in
> > nvdimm_init_nsarea() since NVDIMM-Ns do not implement optinal
> > ND_CMD_GET_CONFIG_DATA command.
> > 
> > Change nvdimm_probe() to accept the case that the CONFIG_DATA
> > command is not implemented for NVDIMM-Ns.  The driver attaches
> > without ndd, which keeps it no-op to the device.
> > 
> > Reported-by: Brian Boylston <brian.boylston@hpe.com>
> > Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
> > Cc: Dan Williams <dan.j.williams@intel.com>
> > ---
> >  drivers/nvdimm/dimm.c      |   10 ++++++++++
> >  drivers/nvdimm/dimm_devs.c |   27 ++++++++++++++++-----------
> >  drivers/nvdimm/nd.h        |    1 +
> >  3 files changed, 27 insertions(+), 11 deletions(-)
> 
> This fails the ndctl unit test suite, see below plus some other
> cleanups...

Sorry, I had overlooked about this test suite... I built it to run the
test and was able to reproduce the failures.

> > 
> > diff --git a/drivers/nvdimm/dimm.c b/drivers/nvdimm/dimm.c
> > index 71d12bb..07e09c2 100644
> > --- a/drivers/nvdimm/dimm.c
> > +++ b/drivers/nvdimm/dimm.c
> > @@ -26,6 +26,13 @@ static int nvdimm_probe(struct device *dev)
> >         struct nvdimm_drvdata *ndd;
> >         int rc;
> > 
> > +       rc = nvdimm_check_config_data(dev);
> > +       if (rc == -ENOENT)
> > +               /* not required for non-aliased nvdimm, ex. NVDIMM-
> > N */
> > +               return 0;
> > +       else
> > +               return rc;
> > +
> 
> Change usage of ENOENT to ENOTTY throughout...

Will do.

> > 
> >         ndd = kzalloc(sizeof(*ndd), GFP_KERNEL);
> >         if (!ndd)
> >                 return -ENOMEM;
> > @@ -72,6 +79,9 @@ static int nvdimm_remove(struct device *dev)
> >  {
> >         struct nvdimm_drvdata *ndd = dev_get_drvdata(dev);
> > 
> > +       if (!ndd)
> > +               return 0;
> > +
> >         nvdimm_bus_lock(dev);
> >         dev_set_drvdata(dev, NULL);
> >         nvdimm_bus_unlock(dev);
> > diff --git a/drivers/nvdimm/dimm_devs.c
> > b/drivers/nvdimm/dimm_devs.c
> > index d9bba5e..fee82d3 100644
> > --- a/drivers/nvdimm/dimm_devs.c
> > +++ b/drivers/nvdimm/dimm_devs.c
> > @@ -28,28 +28,33 @@ static DEFINE_IDA(dimm_ida);
> >   * Retrieve bus and dimm handle and return if this bus supports
> >   * get_config_data commands
> >   */
> > -static int __validate_dimm(struct nvdimm_drvdata *ndd)
> > +int nvdimm_check_config_data(struct device *dev)
> >  {
> > -       struct nvdimm *nvdimm;
> > -
> > -       if (!ndd)
> > -               return -EINVAL;
> > -
> > -       nvdimm = to_nvdimm(ndd->dev);
> > +       struct nvdimm *nvdimm = to_nvdimm(dev);
> > 
> >         if (!nvdimm->cmd_mask)
> > -               return -ENXIO;
> > +               goto err;
> >         if (!test_bit(ND_CMD_GET_CONFIG_DATA, &nvdimm->cmd_mask))
> > -               return -ENXIO;
> > +               goto err;
> > 
> >         return 0;
> > +
> > + err:
> > +       if (nvdimm->flags & NDD_ALIASING)
> > +               return -ENXIO;
> > +       else
> > +               return -ENOENT;
> 
> 
> Let's not use "goto" since there is nothing to unwind.

Got it.

> > 
> >  }
> > 
> >  static int validate_dimm(struct nvdimm_drvdata *ndd)
> >  {
> > -       int rc = __validate_dimm(ndd);
> > +       int rc;
> > 
> > -       if (rc && ndd)
> > +       if (!ndd)
> > +               return -EINVAL;
> 
> Since we've called nvdimm_check_config_data() before allocating ndd
> it will always be NULL causing DIMMs with label areas to fail init.

I am still puzzled at the moment, but will look into the issue.

Thanks!
-Toshi