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From: Vishal Verma <vishal.l.verma@intel.com>
To: linux-nvdimm@lists.01.org
Subject: [ndctl PATCH 5/5] util/json: add a util_namespace_badblocks_to_json() helper
Date: Mon,  1 Oct 2018 21:31:40 -0600	[thread overview]
Message-ID: <20181002033140.21295-5-vishal.l.verma@intel.com> (raw)
In-Reply-To: <20181002033140.21295-1-vishal.l.verma@intel.com>

When ndctl list --media-errors is invoked, we rely upon the 'region'
badblocks provided by the kernel, and reference them against the
namespace start to report namespace badblocks. This can fail for
non-root users, as the region and namespace resource information is
root-only. However the kernel also provides block-device badblocks
information in sysfs, and that is world readable. Provide a new helper
to retrieve this information, and use it as a fallback when the region
based badblocks are unavailable.

Note that when falling back to the namespace based badblocks, we are
unable to retrieve the DIMM on which the badblocks are present, since we
still need root privileges for both getting the resource information,
and for the address translation command.

Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 util/json.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 56 insertions(+), 3 deletions(-)

diff --git a/util/json.c b/util/json.c
index 4dd5fc3..fbc4b83 100644
--- a/util/json.c
+++ b/util/json.c
@@ -506,6 +506,52 @@ struct json_object *util_region_badblocks_to_json(struct ndctl_region *region,
 	return NULL;
 }
 
+static struct json_object *util_namespace_badblocks_to_json(
+			struct ndctl_namespace *ndns,
+			unsigned int *bb_count, unsigned long flags)
+{
+	struct json_object *jbb = NULL, *jbbs = NULL, *jobj;
+	struct badblock *bb;
+	int bbs = 0;
+
+	if (flags & UTIL_JSON_MEDIA_ERRORS) {
+		jbbs = json_object_new_array();
+		if (!jbbs)
+			return NULL;
+	} else
+		return NULL;
+
+	ndctl_namespace_badblock_foreach(ndns, bb) {
+		bbs += bb->len;
+
+		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);
+	}
+
+	*bb_count = 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,
 		unsigned int *bb_count, unsigned long flags)
@@ -593,8 +639,11 @@ static struct json_object *util_pfn_badblocks_to_json(struct ndctl_pfn *pfn,
 	unsigned long long pfn_begin, pfn_size;
 
 	pfn_begin = ndctl_pfn_get_resource(pfn);
-	if (pfn_begin == ULLONG_MAX)
-		return NULL;
+	if (pfn_begin == ULLONG_MAX) {
+		struct ndctl_namespace *ndns = ndctl_pfn_get_namespace(pfn);
+
+		return util_namespace_badblocks_to_json(ndns, bb_count, flags);
+	}
 
 	pfn_size = ndctl_pfn_get_size(pfn);
 	if (pfn_size == ULLONG_MAX)
@@ -873,10 +922,14 @@ struct json_object *util_namespace_to_json(struct ndctl_namespace *ndns,
 		jbbs = util_dax_badblocks_to_json(dax, &bb_count, flags);
 	else if (btt)
 		util_btt_badblocks_to_json(btt, &bb_count);
-	else
+	else {
 		jbbs = util_region_badblocks_to_json(
 				ndctl_namespace_get_region(ndns), &bb_count,
 				flags);
+		if (!jbbs)
+			jbbs = util_namespace_badblocks_to_json(ndns, &bb_count,
+					flags);
+	}
 
 	if (bb_count) {
 		jobj = json_object_new_int(bb_count);
-- 
2.17.1

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  parent reply	other threads:[~2018-10-02  3:31 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-02  3:31 [ndctl PATCH 1/5] ndctl, lib: refactor badblocks retrieval routines Vishal Verma
2018-10-02  3:31 ` [ndctl PATCH 2/5] ndctl, lib: add APIs for retrieving namespace badblocks Vishal Verma
2018-10-02  3:31 ` [ndctl PATCH 3/5] util/json: fix an error check for region resource Vishal Verma
2018-10-03  1:47   ` Dan Williams
2018-10-02  3:31 ` [ndctl PATCH 4/5] util/json: consolidate check for the UTIL_JSON_MEDIA_ERRORS flag Vishal Verma
2018-10-03  1:52   ` Dan Williams
2018-10-02  3:31 ` Vishal Verma [this message]
2018-10-03  1:58   ` [ndctl PATCH 5/5] util/json: add a util_namespace_badblocks_to_json() helper Dan Williams

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