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path: root/drivers/nvdimm/namespace_devs.c
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Diffstat (limited to 'drivers/nvdimm/namespace_devs.c')
-rw-r--r--drivers/nvdimm/namespace_devs.c61
1 files changed, 59 insertions, 2 deletions
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index f05d9b0672bf..c96e31330213 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1411,6 +1411,58 @@ static ssize_t dpa_extents_show(struct device *dev,
}
static DEVICE_ATTR_RO(dpa_extents);
+static int btt_claim_class(struct device *dev)
+{
+ struct nd_region *nd_region = to_nd_region(dev->parent);
+ int i, loop_bitmask = 0;
+
+ for (i = 0; i < nd_region->ndr_mappings; i++) {
+ struct nd_mapping *nd_mapping = &nd_region->mapping[i];
+ struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
+ struct nd_namespace_index *nsindex;
+
+ nsindex = to_namespace_index(ndd, ndd->ns_current);
+ if (nsindex == NULL)
+ loop_bitmask |= 1;
+ else {
+ /* check whether existing labels are v1.1 or v1.2 */
+ if (__le16_to_cpu(nsindex->major) == 1
+ && __le16_to_cpu(nsindex->minor) == 1)
+ loop_bitmask |= 2;
+ else
+ loop_bitmask |= 4;
+ }
+ }
+ /*
+ * If nsindex is null loop_bitmask's bit 0 will be set, and if an index
+ * block is found, a v1.1 label for any mapping will set bit 1, and a
+ * v1.2 label will set bit 2.
+ *
+ * At the end of the loop, at most one of the three bits must be set.
+ * If multiple bits were set, it means the different mappings disagree
+ * about their labels, and this must be cleaned up first.
+ *
+ * If all the label index blocks are found to agree, nsindex of NULL
+ * implies labels haven't been initialized yet, and when they will,
+ * they will be of the 1.2 format, so we can assume BTT2.0
+ *
+ * If 1.1 labels are found, we enforce BTT1.1, and if 1.2 labels are
+ * found, we enforce BTT2.0
+ *
+ * If the loop was never entered, default to BTT1.1 (legacy namespaces)
+ */
+ switch (loop_bitmask) {
+ case 0:
+ case 2:
+ return NVDIMM_CCLASS_BTT;
+ case 1:
+ case 4:
+ return NVDIMM_CCLASS_BTT2;
+ default:
+ return -ENXIO;
+ }
+}
+
static ssize_t holder_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1433,7 +1485,7 @@ static ssize_t __holder_class_store(struct device *dev, const char *buf)
return -EBUSY;
if (strcmp(buf, "btt") == 0 || strcmp(buf, "btt\n") == 0)
- ndns->claim_class = NVDIMM_CCLASS_BTT;
+ ndns->claim_class = btt_claim_class(dev);
else if (strcmp(buf, "pfn") == 0 || strcmp(buf, "pfn\n") == 0)
ndns->claim_class = NVDIMM_CCLASS_PFN;
else if (strcmp(buf, "dax") == 0 || strcmp(buf, "dax\n") == 0)
@@ -1443,6 +1495,10 @@ 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;
}
@@ -1474,7 +1530,8 @@ static ssize_t holder_class_show(struct device *dev,
device_lock(dev);
if (ndns->claim_class == NVDIMM_CCLASS_NONE)
rc = sprintf(buf, "\n");
- else if (ndns->claim_class == NVDIMM_CCLASS_BTT)
+ else if ((ndns->claim_class == NVDIMM_CCLASS_BTT) ||
+ (ndns->claim_class == NVDIMM_CCLASS_BTT2))
rc = sprintf(buf, "btt\n");
else if (ndns->claim_class == NVDIMM_CCLASS_PFN)
rc = sprintf(buf, "pfn\n");

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