6 files changed, 61 insertions, 3 deletions

diff --git a/drivers/nvdimm/blk.c b/drivers/nvdimm/blk.c
index 96ef38ceeceb..4f97b248c236 100644
--- a/drivers/nvdimm/blk.c
+++ b/drivers/nvdimm/blk.c
@@ -232,6 +232,7 @@ static int nd_blk_rw_bytes(struct nd_namespace_common *ndns,
 
 static const struct block_device_operations nd_blk_fops = {
 	.owner = THIS_MODULE,
+	.revalidate_disk = nvdimm_revalidate_disk,
 };
 
 static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
@@ -283,6 +284,7 @@ static int nd_blk_attach_disk(struct nd_namespace_common *ndns,
 	}
 
 	set_capacity(disk, available_disk_size >> SECTOR_SHIFT);
+	revalidate_disk(disk);
 	return 0;
 }
 
diff --git a/drivers/nvdimm/btt.c b/drivers/nvdimm/btt.c
index c02065aed03d..411c7b2bb37a 100644
--- a/drivers/nvdimm/btt.c
+++ b/drivers/nvdimm/btt.c
@@ -1245,6 +1245,7 @@ static const struct block_device_operations btt_fops = {
 	.owner =		THIS_MODULE,
 	.rw_page =		btt_rw_page,
 	.getgeo =		btt_getgeo,
+	.revalidate_disk =	nvdimm_revalidate_disk,
 };
 
 static int btt_blk_init(struct btt *btt)
@@ -1292,6 +1293,7 @@ static int btt_blk_init(struct btt *btt)
 		}
 	}
 	set_capacity(btt->btt_disk, btt->nlba * btt->sector_size >> 9);
+	revalidate_disk(btt->btt_disk);
 
 	return 0;
 }
@@ -1346,7 +1348,11 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
 		goto out_free;
 	}
 
-	if (btt->init_state != INIT_READY) {
+	if (btt->init_state != INIT_READY && nd_region->ro) {
+		dev_info(dev, "%s is read-only, unable to init btt metadata\n",
+				dev_name(&nd_region->dev));
+		goto out_free;
+	} else if (btt->init_state != INIT_READY) {
 		btt->num_arenas = (rawsize / ARENA_MAX_SIZE) +
 			((rawsize % ARENA_MAX_SIZE) ? 1 : 0);
 		dev_dbg(dev, "init: %d arenas for %llu rawsize\n",
@@ -1361,7 +1367,7 @@ static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
 		ret = btt_meta_init(btt);
 		if (ret) {
 			dev_err(dev, "init: error in meta_init: %d\n", ret);
-			return NULL;
+			goto out_free;
 		}
 	}
 
diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index dd12f38397db..ec59f1f26d95 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -227,6 +227,24 @@ int __nd_driver_register(struct nd_device_driver *nd_drv, struct module *owner,
 }
 EXPORT_SYMBOL(__nd_driver_register);
 
+int nvdimm_revalidate_disk(struct gendisk *disk)
+{
+	struct device *dev = disk->driverfs_dev;
+	struct nd_region *nd_region = to_nd_region(dev->parent);
+	const char *pol = nd_region->ro ? "only" : "write";
+
+	if (nd_region->ro == get_disk_ro(disk))
+		return 0;
+
+	dev_info(dev, "%s read-%s, marking %s read-%s\n",
+			dev_name(&nd_region->dev), pol, disk->disk_name, pol);
+	set_disk_ro(disk, nd_region->ro);
+
+	return 0;
+
+}
+EXPORT_SYMBOL(nvdimm_revalidate_disk);
+
 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 		char *buf)
 {
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 4614b00542d1..48b09a210689 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -97,7 +97,7 @@ struct nd_region {
 	u16 ndr_mappings;
 	u64 ndr_size;
 	u64 ndr_start;
-	int id, num_lanes;
+	int id, num_lanes, ro;
 	void *provider_data;
 	struct nd_interleave_set *nd_set;
 	struct nd_percpu_lane __percpu *lane;
@@ -189,6 +189,7 @@ u64 nd_region_interleave_set_cookie(struct nd_region *nd_region);
 void nvdimm_bus_lock(struct device *dev);
 void nvdimm_bus_unlock(struct device *dev);
 bool is_nvdimm_bus_locked(struct device *dev);
+int nvdimm_revalidate_disk(struct gendisk *disk);
 void nvdimm_drvdata_release(struct kref *kref);
 void put_ndd(struct nvdimm_drvdata *ndd);
 int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd);
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index a9709db0704c..42b766f33e59 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -104,6 +104,7 @@ static const struct block_device_operations pmem_fops = {
 	.owner =		THIS_MODULE,
 	.rw_page =		pmem_rw_page,
 	.direct_access =	pmem_direct_access,
+	.revalidate_disk =	nvdimm_revalidate_disk,
 };
 
 static struct pmem_device *pmem_alloc(struct device *dev,
@@ -178,6 +179,7 @@ static int pmem_attach_disk(struct nd_namespace_common *ndns,
 	pmem->pmem_disk = disk;
 
 	add_disk(disk);
+	revalidate_disk(disk);
 
 	return 0;
 }
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 2cfb3f74bcbf..482ee3e4e04a 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -345,11 +345,35 @@ static ssize_t btt_seed_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(btt_seed);
 
+static ssize_t read_only_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct nd_region *nd_region = to_nd_region(dev);
+
+	return sprintf(buf, "%d\n", nd_region->ro);
+}
+
+static ssize_t read_only_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	bool ro;
+	int rc = strtobool(buf, &ro);
+	struct nd_region *nd_region = to_nd_region(dev);
+
+	if (rc)
+		return rc;
+
+	nd_region->ro = ro;
+	return len;
+}
+static DEVICE_ATTR_RW(read_only);
+
 static struct attribute *nd_region_attributes[] = {
 	&dev_attr_size.attr,
 	&dev_attr_nstype.attr,
 	&dev_attr_mappings.attr,
 	&dev_attr_btt_seed.attr,
+	&dev_attr_read_only.attr,
 	&dev_attr_set_cookie.attr,
 	&dev_attr_available_size.attr,
 	&dev_attr_namespace_seed.attr,
@@ -641,6 +665,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 	struct device *dev;
 	void *region_buf;
 	unsigned int i;
+	int ro = 0;
 
 	for (i = 0; i < ndr_desc->num_mappings; i++) {
 		struct nd_mapping *nd_mapping = &ndr_desc->nd_mapping[i];
@@ -652,6 +677,9 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 
 			return NULL;
 		}
+
+		if (nvdimm->flags & NDD_UNARMED)
+			ro = 1;
 	}
 
 	if (dev_type == &nd_blk_device_type) {
@@ -707,6 +735,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,
 	nd_region->provider_data = ndr_desc->provider_data;
 	nd_region->nd_set = ndr_desc->nd_set;
 	nd_region->num_lanes = ndr_desc->num_lanes;
+	nd_region->ro = ro;
 	ida_init(&nd_region->ns_ida);
 	ida_init(&nd_region->btt_ida);
 	dev = &nd_region->dev;