diff mbox

[v3,2/2] ndctl: add list --media-errors support

Message ID 149443929943.16024.5561881574160309534.stgit@djiang5-desk3.ch.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Dave Jiang May 10, 2017, 6:03 p.m. UTC
ACPI NFIT enabled platforms provide media errors as absolute phyiscal
address offsets. Add an option to ndctl to display those media errors
tranlsated to region and namespace device level offsets in an "ndctl
list" listing.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---

v2: added fix to badblocks display from Toshi's testing result.
v3: fixed naming issues from Dan's comments.
    fixed badblocks boundary offset calculations from Toshi's testing.

 ndctl/list.c      |   17 +++++
 ndctl/namespace.c |    2 -
 util/json.c       |  164 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 util/json.h       |    5 +-
 4 files changed, 182 insertions(+), 6 deletions(-)

Comments

Kani, Toshi May 10, 2017, 6:43 p.m. UTC | #1
On Wed, 2017-05-10 at 11:03 -0700, Dave Jiang wrote:
> ACPI NFIT enabled platforms provide media errors as absolute phyiscal

> address offsets. Add an option to ndctl to display those media errors

> tranlsated to region and namespace device level offsets in an "ndctl

> list" listing.

> 

> Signed-off-by: Dave Jiang <dave.jiang@intel.com>

> ---

> 

> v2: added fix to badblocks display from Toshi's testing result.

> v3: fixed naming issues from Dan's comments.

>     fixed badblocks boundary offset calculations from Toshi's

> testing.


Thanks for the quick update.  This version works nicely for dax and
memory modes.  Is there particular reason why it does not list errors
for raw and sector modes?

-Toshi
Dave Jiang May 10, 2017, 7:56 p.m. UTC | #2
On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:
> On Wed, 2017-05-10 at 11:03 -0700, Dave Jiang wrote:
>> ACPI NFIT enabled platforms provide media errors as absolute phyiscal
>> address offsets. Add an option to ndctl to display those media errors
>> tranlsated to region and namespace device level offsets in an "ndctl
>> list" listing.
>>
>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>
>> v2: added fix to badblocks display from Toshi's testing result.
>> v3: fixed naming issues from Dan's comments.
>>     fixed badblocks boundary offset calculations from Toshi's
>> testing.
> 
> Thanks for the quick update.  This version works nicely for dax and
> memory modes.  Is there particular reason why it does not list errors
> for raw and sector modes?

So it should work for raw AFAICT. Dan said the BTT ones don't make sense
because the namespace relative offset is dynamic.


# ./ndctl/ndctl list -NM
[
  {
    "dev":"namespace5.0",
    "mode":"raw",
    "size":33554432,
    "uuid":"bb3539dd-065c-41bd-8bcc-dc3bbc3317a5",
    "badblocks":[
      {
        "offset":4,
        "length":1
      },
      {
        "offset":32768,
        "length":8
      },
      {
        "offset":65528,
        "length":8
      }
    ],
    "blockdev":"pmem5"
  },
Kani, Toshi May 10, 2017, 8:57 p.m. UTC | #3
On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:
> 

> On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:

> > On Wed, 2017-05-10 at 11:03 -0700, Dave Jiang wrote:

> > > ACPI NFIT enabled platforms provide media errors as absolute

> > > phyiscal

> > > address offsets. Add an option to ndctl to display those media

> > > errors

> > > tranlsated to region and namespace device level offsets in an

> > > "ndctl

> > > list" listing.

> > > 

> > > Signed-off-by: Dave Jiang <dave.jiang@intel.com>

> > > ---

> > > 

> > > v2: added fix to badblocks display from Toshi's testing result.

> > > v3: fixed naming issues from Dan's comments.

> > >     fixed badblocks boundary offset calculations from Toshi's

> > > testing.

> > 

> > Thanks for the quick update.  This version works nicely for dax and

> > memory modes.  Is there particular reason why it does not list

> > errors for raw and sector modes?

> 

> So it should work for raw AFAICT. Dan said the BTT ones don't make

> sense because the namespace relative offset is dynamic.

> 

> 

> # ./ndctl/ndctl list -NM

> [

>   {

>     "dev":"namespace5.0",

>     "mode":"raw",

>     "size":33554432,

>     "uuid":"bb3539dd-065c-41bd-8bcc-dc3bbc3317a5",

>     "badblocks":[

>       {

>         "offset":4,

>         "length":1

>       },

>       {

>         "offset":32768,

>         "length":8

>       },

>       {

>         "offset":65528,

>         "length":8

>       }

>     ],

>     "blockdev":"pmem5"

>   },


Attached "strace.log".  Note, there is no reference to "badblocks"
files in the log.

I agree that offsets do not make sense for BTT, but it leads to a false
impression that there is no error.  Perhaps, we can remove "offset" or
put "n/a" for BTT.  

Thanks,
-Toshi
Dave Jiang May 10, 2017, 9:13 p.m. UTC | #4
On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:
> On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:
>>
>> On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:
>>> On Wed, 2017-05-10 at 11:03 -0700, Dave Jiang wrote:
>>>> ACPI NFIT enabled platforms provide media errors as absolute
>>>> phyiscal
>>>> address offsets. Add an option to ndctl to display those media
>>>> errors
>>>> tranlsated to region and namespace device level offsets in an
>>>> "ndctl
>>>> list" listing.
>>>>
>>>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>>>> ---
>>>>
>>>> v2: added fix to badblocks display from Toshi's testing result.
>>>> v3: fixed naming issues from Dan's comments.
>>>>     fixed badblocks boundary offset calculations from Toshi's
>>>> testing.
>>>
>>> Thanks for the quick update.  This version works nicely for dax and
>>> memory modes.  Is there particular reason why it does not list
>>> errors for raw and sector modes?
>>
>> So it should work for raw AFAICT. Dan said the BTT ones don't make
>> sense because the namespace relative offset is dynamic.
>>
>>
>> # ./ndctl/ndctl list -NM
>> [
>>   {
>>     "dev":"namespace5.0",
>>     "mode":"raw",
>>     "size":33554432,
>>     "uuid":"bb3539dd-065c-41bd-8bcc-dc3bbc3317a5",
>>     "badblocks":[
>>       {
>>         "offset":4,
>>         "length":1
>>       },
>>       {
>>         "offset":32768,
>>         "length":8
>>       },
>>       {
>>         "offset":65528,
>>         "length":8
>>       }
>>     ],
>>     "blockdev":"pmem5"
>>   },
> 
> Attached "strace.log".  Note, there is no reference to "badblocks"
> files in the log.

Hmmm....is there any reason my raw namespace is different type than
yours? Do you know if yours hit the else branch on util/json.c:516 in
util_namespace_to_json()? That is the only thing I can think of that
would show no badblocks in the strace.

> 
> I agree that offsets do not make sense for BTT, but it leads to a false
> impression that there is no error.  Perhaps, we can remove "offset" or
> put "n/a" for BTT.

I'm ok with that if Dan has no problem with it.
Kani, Toshi May 10, 2017, 9:28 p.m. UTC | #5
On Wed, 2017-05-10 at 14:13 -0700, Dave Jiang wrote:
> 

> On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:

> > On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:

> > > 

> > > On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:

 :
> > 

> > Attached "strace.log".  Note, there is no reference to "badblocks"

> > files in the log.

> 

> Hmmm....is there any reason my raw namespace is different type than

> yours? Do you know if yours hit the else branch on util/json.c:516 in

> util_namespace_to_json()? That is the only thing I can think of that

> would show no badblocks in the strace.


Yes, it hits the else case.  Not sure if it's related, but our raw
device does not have any metadata so it does not have uuid.

Thanks,
-Toshi
Dave Jiang May 10, 2017, 9:34 p.m. UTC | #6
On 05/10/2017 02:28 PM, Kani, Toshimitsu wrote:
> On Wed, 2017-05-10 at 14:13 -0700, Dave Jiang wrote:
>>
>> On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:
>>> On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:
>>>>
>>>> On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:
>  :
>>>
>>> Attached "strace.log".  Note, there is no reference to "badblocks"
>>> files in the log.
>>
>> Hmmm....is there any reason my raw namespace is different type than
>> yours? Do you know if yours hit the else branch on util/json.c:516 in
>> util_namespace_to_json()? That is the only thing I can think of that
>> would show no badblocks in the strace.
> 
> Yes, it hits the else case.  Not sure if it's related, but our raw
> device does not have any metadata so it does not have uuid.

The raw namespace is not ND_DEVICE_NAMESPACE_IO for you. Maybe that's
correlated to not having uuid? I can add dumping of badblocks to the
else branch. Essentially it's a pass through of the region badblocks for
raw ns.
Kani, Toshi May 10, 2017, 9:47 p.m. UTC | #7
On Wed, 2017-05-10 at 14:34 -0700, Dave Jiang wrote:
> 

> On 05/10/2017 02:28 PM, Kani, Toshimitsu wrote:

> > On Wed, 2017-05-10 at 14:13 -0700, Dave Jiang wrote:

> > > 

> > > On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:

> > > > On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:

> > > > > 

> > > > > On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:

> > 

> >  :

> > > > 

> > > > Attached "strace.log".  Note, there is no reference to

> > > > "badblocks"

> > > > files in the log.

> > > 

> > > Hmmm....is there any reason my raw namespace is different type

> > > than yours? Do you know if yours hit the else branch on

> > > util/json.c:516 in util_namespace_to_json()? That is the only

> > > thing I can think of that would show no badblocks in the strace.

> > 

> > Yes, it hits the else case.  Not sure if it's related, but our raw

> > device does not have any metadata so it does not have uuid.

> 

> The raw namespace is not ND_DEVICE_NAMESPACE_IO for you. Maybe that's

> correlated to not having uuid? I can add dumping of badblocks to the

> else branch. Essentially it's a pass through of the region badblocks

> for raw ns.


Our raw namespace _is_ ND_DEVICE_NAMESPACE_IO.  Yes, it looks like this
is causing the issue.

Thanks,
-Toshi
Dan Williams May 10, 2017, 10:07 p.m. UTC | #8
On Wed, May 10, 2017 at 2:47 PM, Kani, Toshimitsu <toshi.kani@hpe.com> wrote:
> On Wed, 2017-05-10 at 14:34 -0700, Dave Jiang wrote:
>>
>> On 05/10/2017 02:28 PM, Kani, Toshimitsu wrote:
>> > On Wed, 2017-05-10 at 14:13 -0700, Dave Jiang wrote:
>> > >
>> > > On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:
>> > > > On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:
>> > > > >
>> > > > > On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:
>> >
>> >  :
>> > > >
>> > > > Attached "strace.log".  Note, there is no reference to
>> > > > "badblocks"
>> > > > files in the log.
>> > >
>> > > Hmmm....is there any reason my raw namespace is different type
>> > > than yours? Do you know if yours hit the else branch on
>> > > util/json.c:516 in util_namespace_to_json()? That is the only
>> > > thing I can think of that would show no badblocks in the strace.
>> >
>> > Yes, it hits the else case.  Not sure if it's related, but our raw
>> > device does not have any metadata so it does not have uuid.
>>
>> The raw namespace is not ND_DEVICE_NAMESPACE_IO for you. Maybe that's
>> correlated to not having uuid? I can add dumping of badblocks to the
>> else branch. Essentially it's a pass through of the region badblocks
>> for raw ns.
>
> Our raw namespace _is_ ND_DEVICE_NAMESPACE_IO.  Yes, it looks like this
> is causing the issue.

Yeah, that's my fault. I told Dave that we did not need to worry about
memmap= namespaces, but as far as ndctl is concerned memmap= and other
NVDIMMs without labels are identical.
Dan Williams May 10, 2017, 10:24 p.m. UTC | #9
On Wed, May 10, 2017 at 2:13 PM, Dave Jiang <dave.jiang@intel.com> wrote:
>
>
> On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:
>> On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:
>>>
>>> On 05/10/2017 11:43 AM, Kani, Toshimitsu wrote:
>>>> On Wed, 2017-05-10 at 11:03 -0700, Dave Jiang wrote:
>>>>> ACPI NFIT enabled platforms provide media errors as absolute
>>>>> phyiscal
>>>>> address offsets. Add an option to ndctl to display those media
>>>>> errors
>>>>> tranlsated to region and namespace device level offsets in an
>>>>> "ndctl
>>>>> list" listing.
>>>>>
>>>>> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
>>>>> ---
>>>>>
>>>>> v2: added fix to badblocks display from Toshi's testing result.
>>>>> v3: fixed naming issues from Dan's comments.
>>>>>     fixed badblocks boundary offset calculations from Toshi's
>>>>> testing.
>>>>
>>>> Thanks for the quick update.  This version works nicely for dax and
>>>> memory modes.  Is there particular reason why it does not list
>>>> errors for raw and sector modes?
>>>
>>> So it should work for raw AFAICT. Dan said the BTT ones don't make
>>> sense because the namespace relative offset is dynamic.
>>>
>>>
>>> # ./ndctl/ndctl list -NM
>>> [
>>>   {
>>>     "dev":"namespace5.0",
>>>     "mode":"raw",
>>>     "size":33554432,
>>>     "uuid":"bb3539dd-065c-41bd-8bcc-dc3bbc3317a5",
>>>     "badblocks":[
>>>       {
>>>         "offset":4,
>>>         "length":1
>>>       },
>>>       {
>>>         "offset":32768,
>>>         "length":8
>>>       },
>>>       {
>>>         "offset":65528,
>>>         "length":8
>>>       }
>>>     ],
>>>     "blockdev":"pmem5"
>>>   },
>>
>> Attached "strace.log".  Note, there is no reference to "badblocks"
>> files in the log.
>
> Hmmm....is there any reason my raw namespace is different type than
> yours? Do you know if yours hit the else branch on util/json.c:516 in
> util_namespace_to_json()? That is the only thing I can think of that
> would show no badblocks in the strace.
>
>>
>> I agree that offsets do not make sense for BTT, but it leads to a false
>> impression that there is no error.  Perhaps, we can remove "offset" or
>> put "n/a" for BTT.
>
> I'm ok with that if Dan has no problem with it.
>

It doesn't strike me as the best path forward. Ideally what we need is
a customized btt badblocks interface that knows how to reverse lookup
media errors into active / btt relative sector offsets. Until we have
that, to list the errors that are associated with the btt namespace
you need to reload it in raw mode or just relay on the parent region
media error list. Now, that said I wouldn't mind if we had a flag that
indicates whether badblocks are present or not by default, and then -M
tries to list them. Something like this where we have 2 namespaces in
the same region that has badblocks:

# ndctl list
[
  {
    "dev":"namespace0.0",
    "mode":"sector",
    "size":4294967296,
    "uuid":"3f45c754-5e8e-4d3e-89db-53ae5cc5a9bd",
    "blockdev":"pmem0s",
    "has_badblocks":true,
  },
  {
    "dev":"namespace0.1",
    "mode":"memory",
    "size":15852371968,
    "uuid":"6446b3bd-b64a-4163-b542-d82ed557fb78",
    "blockdev":"pmem0.1"
    "has_badblocks":true,
 },
]

# ndctl list -M
[
  {
    "dev":"namespace0.0",
    "mode":"sector",
    "size":4294967296,
    "uuid":"3f45c754-5e8e-4d3e-89db-53ae5cc5a9bd",
    "blockdev":"pmem0s",
    "has_badblocks":true,
  },
  {
    "dev":"namespace0.1",
    "mode":"memory",
    "size":15852371968,
    "uuid":"6446b3bd-b64a-4163-b542-d82ed557fb78",
    "blockdev":"pmem0.1"
    "has_badblocks":true,
    "badblocks":[
      {
        "offset":4,
        "length":1
      },
 },
]

In the common case where there are no badblocks we can just had the
"has_badblocks" boolean.
Kani, Toshi May 10, 2017, 10:33 p.m. UTC | #10
On Wed, 2017-05-10 at 15:24 -0700, Dan Williams wrote:
> On Wed, May 10, 2017 at 2:13 PM, Dave Jiang <dave.jiang@intel.com>

> wrote:

> > On 05/10/2017 01:57 PM, Kani, Toshimitsu wrote:

> > > On Wed, 2017-05-10 at 12:56 -0700, Dave Jiang wrote:

> > > > 

 :
> > > 

> > > I agree that offsets do not make sense for BTT, but it leads to a

> > > false impression that there is no error.  Perhaps, we can remove

> > > "offset" or put "n/a" for BTT.

> > 

> > I'm ok with that if Dan has no problem with it.

> > 

> 

> It doesn't strike me as the best path forward. Ideally what we need

> is a customized btt badblocks interface that knows how to reverse

> lookup media errors into active / btt relative sector offsets. Until

> we have that, to list the errors that are associated with the btt

> namespace you need to reload it in raw mode or just relay on the

> parent region media error list. Now, that said I wouldn't mind if we

> had a flag that indicates whether badblocks are present or not by

> default, and then -M tries to list them. Something like this where we

> have 2 namespaces in the same region that has badblocks:

> 

> # ndctl list

> [

>   {

>     "dev":"namespace0.0",

>     "mode":"sector",

>     "size":4294967296,

>     "uuid":"3f45c754-5e8e-4d3e-89db-53ae5cc5a9bd",

>     "blockdev":"pmem0s",

>     "has_badblocks":true,

>   },

>   {

>     "dev":"namespace0.1",

>     "mode":"memory",

>     "size":15852371968,

>     "uuid":"6446b3bd-b64a-4163-b542-d82ed557fb78",

>     "blockdev":"pmem0.1"

>     "has_badblocks":true,

>  },

> ]

> 

> # ndctl list -M

> [

>   {

>     "dev":"namespace0.0",

>     "mode":"sector",

>     "size":4294967296,

>     "uuid":"3f45c754-5e8e-4d3e-89db-53ae5cc5a9bd",

>     "blockdev":"pmem0s",

>     "has_badblocks":true,

>   },

>   {

>     "dev":"namespace0.1",

>     "mode":"memory",

>     "size":15852371968,

>     "uuid":"6446b3bd-b64a-4163-b542-d82ed557fb78",

>     "blockdev":"pmem0.1"

>     "has_badblocks":true,

>     "badblocks":[

>       {

>         "offset":4,

>         "length":1

>       },

>  },

> ]

> 

> In the common case where there are no badblocks we can just had the

> "has_badblocks" boolean.


Good idea!  With "has_badblocks" info, yes, we can avoid the false
impression I concerned about, and can wait for a customized btt
badblocks interface.

Thanks,
-Toshi
diff mbox

Patch

diff --git a/ndctl/list.c b/ndctl/list.c
index 536d333..5fb0c59 100644
--- a/ndctl/list.c
+++ b/ndctl/list.c
@@ -24,6 +24,7 @@  static struct {
 	bool idle;
 	bool health;
 	bool dax;
+	bool media_errors;
 } list;
 
 static struct {
@@ -99,7 +100,8 @@  static struct json_object *list_namespaces(struct ndctl_region *region,
 						jnamespaces);
 		}
 
-		jndns = util_namespace_to_json(ndns, list.idle, list.dax);
+		jndns = util_namespace_to_json(ndns, list.idle, list.dax,
+				list.media_errors);
 		if (!jndns) {
 			fail("\n");
 			continue;
@@ -117,7 +119,8 @@  static struct json_object *list_namespaces(struct ndctl_region *region,
 	return NULL;
 }
 
-static struct json_object *region_to_json(struct ndctl_region *region)
+static struct json_object *region_to_json(struct ndctl_region *region,
+		bool include_media_err)
 {
 	struct json_object *jregion = json_object_new_object();
 	struct json_object *jobj, *jmappings = NULL;
@@ -203,6 +206,12 @@  static struct json_object *region_to_json(struct ndctl_region *region)
 		json_object_object_add(jregion, "state", jobj);
 	}
 
+	if (include_media_err) {
+		jobj = util_region_badblocks_to_json(region);
+		if (jobj)
+			json_object_object_add(jregion, "badblocks", jobj);
+	}
+
 	list_namespaces(region, jregion, NULL, false);
 	return jregion;
  err:
@@ -240,6 +249,8 @@  int cmd_list(int argc, const char **argv, void *ctx)
 		OPT_BOOLEAN('X', "device-dax", &list.dax,
 				"include device-dax info"),
 		OPT_BOOLEAN('i', "idle", &list.idle, "include idle devices"),
+		OPT_BOOLEAN('M', "media-errors", &list.media_errors,
+				"include media errors"),
 		OPT_END(),
 	};
 	const char * const u[] = {
@@ -404,7 +415,7 @@  int cmd_list(int argc, const char **argv, void *ctx)
 							jregions);
 			}
 
-			jregion = region_to_json(region);
+			jregion = region_to_json(region, list.media_errors);
 			if (!jregion) {
 				fail("\n");
 				continue;
diff --git a/ndctl/namespace.c b/ndctl/namespace.c
index 89b9b6a..6e150b1 100644
--- a/ndctl/namespace.c
+++ b/ndctl/namespace.c
@@ -392,7 +392,7 @@  static int setup_namespace(struct ndctl_region *region,
 		error("%s: failed to enable\n",
 				ndctl_namespace_get_devname(ndns));
 	} else {
-		struct json_object *jndns = util_namespace_to_json(ndns, 0, 1);
+		struct json_object *jndns = util_namespace_to_json(ndns, 0, 1, 0);
 
 		if (jndns)
 			printf("%s\n", json_object_to_json_string_ext(jndns,
diff --git a/util/json.c b/util/json.c
index 07fd113..6b65466 100644
--- a/util/json.c
+++ b/util/json.c
@@ -233,8 +233,149 @@  struct json_object *util_daxctl_region_to_json(struct daxctl_region *region,
 	return NULL;
 }
 
+struct json_object *util_region_badblocks_to_json(struct ndctl_region *region)
+{
+	struct json_object *jbb = NULL, *jbbs, *jobj;
+	struct badblock *bb;
+	int bbs = 0;
+
+	jbbs = json_object_new_array();
+	if (!jbbs)
+		return NULL;
+
+	ndctl_region_badblock_foreach(region, bb) {
+		jbb = json_object_new_object();
+		if (!jbb)
+			goto err_array;
+
+		jobj = json_object_new_int64(bb->offset);
+		if (!jobj)
+			goto err;
+		json_object_object_add(jbb, "offset", jobj);
+
+		jobj = json_object_new_int(bb->len);
+		if (!jobj)
+			goto err;
+		json_object_object_add(jbb, "length", jobj);
+
+		json_object_array_add(jbbs, jbb);
+		bbs++;
+	}
+
+	if (bbs)
+		return jbbs;
+
+ err:
+	json_object_put(jbb);
+ err_array:
+	json_object_put(jbbs);
+	return NULL;
+}
+
+static struct json_object *dev_badblocks_to_json(struct ndctl_region *region,
+		unsigned long long dev_begin, unsigned long long dev_size)
+{
+	struct json_object *jbb = NULL, *jbbs, *jobj;
+	unsigned long long region_begin, dev_end, offset;
+	unsigned int len, bbs = 0;
+	struct badblock *bb;
+
+	region_begin = ndctl_region_get_resource(region);
+	if (region_begin == ULLONG_MAX)
+		return NULL;
+
+	dev_end = dev_begin + dev_size - 1;
+
+	jbbs = json_object_new_array();
+	if (!jbbs)
+		return NULL;
+
+	ndctl_region_badblock_foreach(region, bb) {
+		unsigned long long bb_begin, bb_end, begin, end;
+
+		bb_begin = region_begin + (bb->offset << 9);
+		bb_end = bb_begin + (bb->len << 9) - 1;
+
+		if (bb_end <= dev_begin || bb_begin >= dev_end)
+			continue;
+
+		if (bb_begin < dev_begin)
+			begin = dev_begin;
+		else
+			begin = bb_begin;
+
+		if (bb_end > dev_end)
+			end = dev_end;
+		else
+			end = bb_end;
+
+		offset = (begin - dev_begin) >> 9;
+		len = (end - begin + 1) >> 9;
+
+		/* add to json */
+		jbb = json_object_new_object();
+		if (!jbb)
+			goto err_array;
+
+		jobj = json_object_new_int64(offset);
+		if (!jobj)
+			goto err;
+		json_object_object_add(jbb, "offset", jobj);
+
+		jobj = json_object_new_int(len);
+		if (!jobj)
+			goto err;
+		json_object_object_add(jbb, "length", jobj);
+
+		json_object_array_add(jbbs, jbb);
+		bbs++;
+	}
+
+	if (bbs)
+		return jbbs;
+
+ err:
+	json_object_put(jbb);
+ err_array:
+	json_object_put(jbbs);
+	return NULL;
+}
+
+struct json_object *util_pfn_badblocks_to_json(struct ndctl_pfn *pfn)
+{
+	struct ndctl_region *region = ndctl_pfn_get_region(pfn);
+	unsigned long long pfn_begin, pfn_size;
+
+	pfn_begin = ndctl_pfn_get_resource(pfn);
+	if (pfn_begin == ULLONG_MAX)
+		return NULL;
+
+	pfn_size = ndctl_pfn_get_size(pfn);
+	if (pfn_size == ULLONG_MAX)
+		return NULL;
+
+	return dev_badblocks_to_json(region, pfn_begin, pfn_size);
+}
+
+struct json_object *util_dax_badblocks_to_json(struct ndctl_dax *dax)
+{
+	struct ndctl_region *region = ndctl_dax_get_region(dax);
+	unsigned long long dax_begin, dax_size;
+
+	dax_begin = ndctl_dax_get_resource(dax);
+	if (dax_begin == ULLONG_MAX)
+		return NULL;
+
+	dax_size = ndctl_dax_get_size(dax);
+	if (dax_size == ULLONG_MAX)
+		return NULL;
+
+	return dev_badblocks_to_json(region, dax_begin, dax_size);
+}
+
 struct json_object *util_namespace_to_json(struct ndctl_namespace *ndns,
-		bool include_idle, bool include_dax)
+		bool include_idle, bool include_dax,
+		bool include_media_errors)
 {
 	struct json_object *jndns = json_object_new_object();
 	unsigned long long size = ULLONG_MAX;
@@ -317,6 +458,12 @@  struct json_object *util_namespace_to_json(struct ndctl_namespace *ndns,
 			goto err;
 		json_object_object_add(jndns, "uuid", jobj);
 		bdev = ndctl_pfn_get_block_device(pfn);
+		if (include_media_errors) {
+			jobj = util_pfn_badblocks_to_json(pfn);
+			if (jobj)
+				json_object_object_add(jndns,
+						"badblocks", jobj);
+		}
 	} else if (dax) {
 		struct daxctl_region *dax_region;
 
@@ -333,6 +480,12 @@  struct json_object *util_namespace_to_json(struct ndctl_namespace *ndns,
 			if (jobj)
 				json_object_object_add(jndns, "daxregion", jobj);
 		}
+		if (include_media_errors) {
+			jobj = util_dax_badblocks_to_json(dax);
+			if (jobj)
+				json_object_object_add(jndns,
+						"badblocks", jobj);
+		}
 	} else if (ndctl_namespace_get_type(ndns) != ND_DEVICE_NAMESPACE_IO) {
 		const char *name;
 
@@ -351,6 +504,15 @@  struct json_object *util_namespace_to_json(struct ndctl_namespace *ndns,
 			json_object_object_add(jndns, "name", jobj);
 		}
 		bdev = ndctl_namespace_get_block_device(ndns);
+		if (include_media_errors) {
+			struct ndctl_region *region =
+				ndctl_namespace_get_region(ndns);
+
+			jobj = util_region_badblocks_to_json(region);
+			if (jobj)
+				json_object_object_add(jndns,
+						"badblocks", jobj);
+		}
 	} else
 		bdev = ndctl_namespace_get_block_device(ndns);
 
diff --git a/util/json.h b/util/json.h
index 2449c2d..ef1d606 100644
--- a/util/json.h
+++ b/util/json.h
@@ -10,9 +10,12 @@  struct json_object *util_bus_to_json(struct ndctl_bus *bus);
 struct json_object *util_dimm_to_json(struct ndctl_dimm *dimm);
 struct json_object *util_mapping_to_json(struct ndctl_mapping *mapping);
 struct json_object *util_namespace_to_json(struct ndctl_namespace *ndns,
-		bool include_idle, bool include_dax);
+		bool include_idle, bool include_dax, bool include_media_errs);
 struct daxctl_region;
 struct daxctl_dev;
+struct json_object *util_dax_badblocks_to_json(struct ndctl_dax *dax);
+struct json_object *util_pfn_badblocks_to_json(struct ndctl_pfn *pfn);
+struct json_object *util_region_badblocks_to_json(struct ndctl_region *region);
 struct json_object *util_daxctl_region_to_json(struct daxctl_region *region,
 		bool include_devs, const char *ident, bool include_idle);
 struct json_object *util_daxctl_dev_to_json(struct daxctl_dev *dev);