libnvdimm/labels: Add uuid helpers

In preparation for CXL labels that move the uuid to a different offset
in the label, add nsl_{ref,get,validate}_uuid(). These helpers use the
proper uuid_t type. That type definition predated the libnvdimm
subsystem, so now is as a good a time as any to convert all the uuid
handling in the subsystem to uuid_t to match the helpers.

Note that the uuid fields in the label data and superblocks is not
replaced per Andy's expectation that uuid_t is a kernel internal type
not to appear in external ABI interfaces. So, in those case
{import,export}_uuid() is used to go between the 2 types.

Also note that this rework uncovered some unnecessary copies for label
comparisons, those are cleaned up with nsl_uuid_equal().

As for the whitespace changes, all new code is clang-format compliant.
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/163116429748.2460985.15659993454313919977.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/btt.c

@@ -973,7 +973,7 @@ static int btt_arena_write_layout(struct arena_info *arena)
 	u64 sum;
 	struct btt_sb *super;
 	struct nd_btt *nd_btt = arena->nd_btt;
-	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
+	const uuid_t *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
 
 	ret = btt_map_init(arena);
 	if (ret)
@@ -988,8 +988,8 @@ static int btt_arena_write_layout(struct arena_info *arena)
 		return -ENOMEM;
 
 	strncpy(super->signature, BTT_SIG, BTT_SIG_LEN);
-	memcpy(super->uuid, nd_btt->uuid, 16);
-	memcpy(super->parent_uuid, parent_uuid, 16);
+	export_uuid(super->uuid, nd_btt->uuid);
+	export_uuid(super->parent_uuid, parent_uuid);
 	super->flags = cpu_to_le32(arena->flags);
 	super->version_major = cpu_to_le16(arena->version_major);
 	super->version_minor = cpu_to_le16(arena->version_minor);
@@ -1575,7 +1575,8 @@ static void btt_blk_cleanup(struct btt *btt)
  * Pointer to a new struct btt on success, NULL on failure.
  */
 static struct btt *btt_init(struct nd_btt *nd_btt, unsigned long long rawsize,
-		u32 lbasize, u8 *uuid, struct nd_region *nd_region)
+			    u32 lbasize, uuid_t *uuid,
+			    struct nd_region *nd_region)
 {
 	int ret;
 	struct btt *btt;

drivers/nvdimm/btt_devs.c

@@ -180,7 +180,7 @@ bool is_nd_btt(struct device *dev)
 EXPORT_SYMBOL(is_nd_btt);
 
 static struct device *__nd_btt_create(struct nd_region *nd_region,
-		unsigned long lbasize, u8 *uuid,
+				      unsigned long lbasize, uuid_t *uuid,
 				      struct nd_namespace_common *ndns)
 {
 	struct nd_btt *nd_btt;
@@ -244,14 +244,16 @@ struct device *nd_btt_create(struct nd_region *nd_region)
  */
 bool nd_btt_arena_is_valid(struct nd_btt *nd_btt, struct btt_sb *super)
 {
-	const u8 *parent_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
+	const uuid_t *ns_uuid = nd_dev_to_uuid(&nd_btt->ndns->dev);
+	uuid_t parent_uuid;
 	u64 checksum;
 
 	if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
 		return false;
 
-	if (!guid_is_null((guid_t *)&super->parent_uuid))
-		if (memcmp(super->parent_uuid, parent_uuid, 16) != 0)
+	import_uuid(&parent_uuid, super->parent_uuid);
+	if (!uuid_is_null(&parent_uuid))
+		if (!uuid_equal(&parent_uuid, ns_uuid))
 			return false;
 
 	checksum = le64_to_cpu(super->checksum);
@@ -319,7 +321,7 @@ static int __nd_btt_probe(struct nd_btt *nd_btt,
 		return rc;
 
 	nd_btt->lbasize = le32_to_cpu(btt_sb->external_lbasize);
-	nd_btt->uuid = kmemdup(btt_sb->uuid, 16, GFP_KERNEL);
+	nd_btt->uuid = kmemdup(&btt_sb->uuid, sizeof(uuid_t), GFP_KERNEL);
 	if (!nd_btt->uuid)
 		return -ENOMEM;
 

drivers/nvdimm/core.c

@@ -206,38 +206,6 @@ struct device *to_nvdimm_bus_dev(struct nvdimm_bus *nvdimm_bus)
 }
 EXPORT_SYMBOL_GPL(to_nvdimm_bus_dev);
 
-static bool is_uuid_sep(char sep)
-{
-	if (sep == '\n' || sep == '-' || sep == ':' || sep == '\0')
-		return true;
-	return false;
-}
-
-static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
-		size_t len)
-{
-	const char *str = buf;
-	u8 uuid[16];
-	int i;
-
-	for (i = 0; i < 16; i++) {
-		if (!isxdigit(str[0]) || !isxdigit(str[1])) {
-			dev_dbg(dev, "pos: %d buf[%zd]: %c buf[%zd]: %c\n",
-					i, str - buf, str[0],
-					str + 1 - buf, str[1]);
-			return -EINVAL;
-		}
-
-		uuid[i] = (hex_to_bin(str[0]) << 4) | hex_to_bin(str[1]);
-		str += 2;
-		if (is_uuid_sep(*str))
-			str++;
-	}
-
-	memcpy(uuid_out, uuid, sizeof(uuid));
-	return 0;
-}
-
 /**
  * nd_uuid_store: common implementation for writing 'uuid' sysfs attributes
  * @dev: container device for the uuid property
@@ -248,21 +216,21 @@ static int nd_uuid_parse(struct device *dev, u8 *uuid_out, const char *buf,
  * (driver detached)
  * LOCKING: expects nd_device_lock() is held on entry
  */
-int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
+int nd_uuid_store(struct device *dev, uuid_t **uuid_out, const char *buf,
 		size_t len)
 {
-	u8 uuid[16];
+	uuid_t uuid;
 	int rc;
 
 	if (dev->driver)
 		return -EBUSY;
 
-	rc = nd_uuid_parse(dev, uuid, buf, len);
+	rc = uuid_parse(buf, &uuid);
 	if (rc)
 		return rc;
 
 	kfree(*uuid_out);
-	*uuid_out = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
+	*uuid_out = kmemdup(&uuid, sizeof(uuid), GFP_KERNEL);
 	if (!(*uuid_out))
 		return -ENOMEM;
 

drivers/nvdimm/label.c

@@ -321,7 +321,8 @@ static bool preamble_index(struct nvdimm_drvdata *ndd, int idx,
 	return true;
 }
 
-char *nd_label_gen_id(struct nd_label_id *label_id, u8 *uuid, u32 flags)
+char *nd_label_gen_id(struct nd_label_id *label_id, const uuid_t *uuid,
+		      u32 flags)
 {
 	if (!label_id || !uuid)
 		return NULL;
@@ -400,9 +401,9 @@ int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
 		struct nvdimm *nvdimm = to_nvdimm(ndd->dev);
 		struct nd_namespace_label *nd_label;
 		struct nd_region *nd_region = NULL;
-		u8 label_uuid[NSLABEL_UUID_LEN];
 		struct nd_label_id label_id;
 		struct resource *res;
+		uuid_t label_uuid;
 		u32 flags;
 
 		nd_label = to_label(ndd, slot);
@@ -410,11 +411,11 @@ int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
 		if (!slot_valid(ndd, nd_label, slot))
 			continue;
 
-		memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
+		nsl_get_uuid(ndd, nd_label, &label_uuid);
 		flags = nsl_get_flags(ndd, nd_label);
 		if (test_bit(NDD_NOBLK, &nvdimm->flags))
 			flags &= ~NSLABEL_FLAG_LOCAL;
-		nd_label_gen_id(&label_id, label_uuid, flags);
+		nd_label_gen_id(&label_id, &label_uuid, flags);
 		res = nvdimm_allocate_dpa(ndd, &label_id,
 					  nsl_get_dpa(ndd, nd_label),
 					  nsl_get_rawsize(ndd, nd_label));
@@ -851,7 +852,7 @@ static int __pmem_label_update(struct nd_region *nd_region,
 
 	nd_label = to_label(ndd, slot);
 	memset(nd_label, 0, sizeof_namespace_label(ndd));
-	memcpy(nd_label->uuid, nspm->uuid, NSLABEL_UUID_LEN);
+	nsl_set_uuid(ndd, nd_label, nspm->uuid);
 	nsl_set_name(ndd, nd_label, nspm->alt_name);
 	nsl_set_flags(ndd, nd_label, flags);
 	nsl_set_nlabel(ndd, nd_label, nd_region->ndr_mappings);
@@ -878,9 +879,8 @@ static int __pmem_label_update(struct nd_region *nd_region,
 	list_for_each_entry(label_ent, &nd_mapping->labels, list) {
 		if (!label_ent->label)
 			continue;
-		if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags)
-				|| memcmp(nspm->uuid, label_ent->label->uuid,
-					NSLABEL_UUID_LEN) == 0)
+		if (test_and_clear_bit(ND_LABEL_REAP, &label_ent->flags) ||
+		    nsl_uuid_equal(ndd, label_ent->label, nspm->uuid))
 			reap_victim(nd_mapping, label_ent);
 	}
 
@@ -1005,7 +1005,6 @@ static int __blk_label_update(struct nd_region *nd_region,
 	unsigned long *free, *victim_map = NULL;
 	struct resource *res, **old_res_list;
 	struct nd_label_id label_id;
-	u8 uuid[NSLABEL_UUID_LEN];
 	int min_dpa_idx = 0;
 	LIST_HEAD(list);
 	u32 nslot, slot;
@@ -1043,8 +1042,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 		/* mark unused labels for garbage collection */
 		for_each_clear_bit_le(slot, free, nslot) {
 			nd_label = to_label(ndd, slot);
-			memcpy(uuid, nd_label->uuid, NSLABEL_UUID_LEN);
-			if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) != 0)
+			if (!nsl_uuid_equal(ndd, nd_label, nsblk->uuid))
 				continue;
 			res = to_resource(ndd, nd_label);
 			if (res && is_old_resource(res, old_res_list,
@@ -1113,7 +1111,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 
 		nd_label = to_label(ndd, slot);
 		memset(nd_label, 0, sizeof_namespace_label(ndd));
-		memcpy(nd_label->uuid, nsblk->uuid, NSLABEL_UUID_LEN);
+		nsl_set_uuid(ndd, nd_label, nsblk->uuid);
 		nsl_set_name(ndd, nd_label, nsblk->alt_name);
 		nsl_set_flags(ndd, nd_label, NSLABEL_FLAG_LOCAL);
 
@@ -1161,8 +1159,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 		if (!nd_label)
 			continue;
 		nlabel++;
-		memcpy(uuid, nd_label->uuid, NSLABEL_UUID_LEN);
-		if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) != 0)
+		if (!nsl_uuid_equal(ndd, nd_label, nsblk->uuid))
 			continue;
 		nlabel--;
 		list_move(&label_ent->list, &list);
@@ -1192,8 +1189,7 @@ static int __blk_label_update(struct nd_region *nd_region,
 	}
 	for_each_clear_bit_le(slot, free, nslot) {
 		nd_label = to_label(ndd, slot);
-		memcpy(uuid, nd_label->uuid, NSLABEL_UUID_LEN);
-		if (memcmp(uuid, nsblk->uuid, NSLABEL_UUID_LEN) != 0)
+		if (!nsl_uuid_equal(ndd, nd_label, nsblk->uuid))
 			continue;
 		res = to_resource(ndd, nd_label);
 		res->flags &= ~DPA_RESOURCE_ADJUSTED;
@@ -1273,12 +1269,11 @@ static int init_labels(struct nd_mapping *nd_mapping, int num_labels)
 	return max(num_labels, old_num_labels);
 }
 
-static int del_labels(struct nd_mapping *nd_mapping, u8 *uuid)
+static int del_labels(struct nd_mapping *nd_mapping, uuid_t *uuid)
 {
 	struct nvdimm_drvdata *ndd = to_ndd(nd_mapping);
 	struct nd_label_ent *label_ent, *e;
 	struct nd_namespace_index *nsindex;
-	u8 label_uuid[NSLABEL_UUID_LEN];
 	unsigned long *free;
 	LIST_HEAD(list);
 	u32 nslot, slot;
@@ -1298,8 +1293,7 @@ static int del_labels(struct nd_mapping *nd_mapping, u8 *uuid)
 		if (!nd_label)
 			continue;
 		active++;
-		memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
-		if (memcmp(label_uuid, uuid, NSLABEL_UUID_LEN) != 0)
+		if (!nsl_uuid_equal(ndd, nd_label, uuid))
 			continue;
 		active--;
 		slot = to_slot(ndd, nd_label);

drivers/nvdimm/nd-core.h

@@ -126,8 +126,9 @@ void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus);
 void nd_synchronize(void);
 void __nd_device_register(struct device *dev);
 struct nd_label_id;
-char *nd_label_gen_id(struct nd_label_id *label_id, u8 *uuid, u32 flags);
-bool nd_is_uuid_unique(struct device *dev, u8 *uuid);
+char *nd_label_gen_id(struct nd_label_id *label_id, const uuid_t *uuid,
+		      u32 flags);
+bool nd_is_uuid_unique(struct device *dev, uuid_t *uuid);
 struct nd_region;
 struct nvdimm_drvdata;
 struct nd_mapping;

drivers/nvdimm/nd.h

@@ -177,6 +177,38 @@ static inline void nsl_set_lbasize(struct nvdimm_drvdata *ndd,
 	nd_label->lbasize = __cpu_to_le64(lbasize);
 }
 
+static inline const uuid_t *nsl_get_uuid(struct nvdimm_drvdata *ndd,
+					 struct nd_namespace_label *nd_label,
+					 uuid_t *uuid)
+{
+	import_uuid(uuid, nd_label->uuid);
+	return uuid;
+}
+
+static inline const uuid_t *nsl_set_uuid(struct nvdimm_drvdata *ndd,
+					 struct nd_namespace_label *nd_label,
+					 const uuid_t *uuid)
+{
+	export_uuid(nd_label->uuid, uuid);
+	return uuid;
+}
+
+static inline bool nsl_uuid_equal(struct nvdimm_drvdata *ndd,
+				  struct nd_namespace_label *nd_label,
+				  const uuid_t *uuid)
+{
+	uuid_t tmp;
+
+	import_uuid(&tmp, nd_label->uuid);
+	return uuid_equal(&tmp, uuid);
+}
+
+static inline const u8 *nsl_uuid_raw(struct nvdimm_drvdata *ndd,
+				     struct nd_namespace_label *nd_label)
+{
+	return nd_label->uuid;
+}
+
 bool nsl_validate_blk_isetcookie(struct nvdimm_drvdata *ndd,
 				 struct nd_namespace_label *nd_label,
 				 u64 isetcookie);
@@ -335,7 +367,7 @@ struct nd_btt {
 	struct btt *btt;
 	unsigned long lbasize;
 	u64 size;
-	u8 *uuid;
+	uuid_t *uuid;
 	int id;
 	int initial_offset;
 	u16 version_major;
@@ -350,7 +382,7 @@ enum nd_pfn_mode {
 
 struct nd_pfn {
 	int id;
-	u8 *uuid;
+	uuid_t *uuid;
 	struct device dev;
 	unsigned long align;
 	unsigned long npfns;
@@ -378,7 +410,7 @@ void wait_nvdimm_bus_probe_idle(struct device *dev);
 void nd_device_register(struct device *dev);
 void nd_device_unregister(struct device *dev, enum nd_async_mode mode);
 void nd_device_notify(struct device *dev, enum nvdimm_event event);
-int nd_uuid_store(struct device *dev, u8 **uuid_out, const char *buf,
+int nd_uuid_store(struct device *dev, uuid_t **uuid_out, const char *buf,
 		size_t len);
 ssize_t nd_size_select_show(unsigned long current_size,
 		const unsigned long *supported, char *buf);
@@ -561,6 +593,6 @@ static inline bool is_bad_pmem(struct badblocks *bb, sector_t sector,
 	return false;
 }
 resource_size_t nd_namespace_blk_validate(struct nd_namespace_blk *nsblk);
-const u8 *nd_dev_to_uuid(struct device *dev);
+const uuid_t *nd_dev_to_uuid(struct device *dev);
 bool pmem_should_map_pages(struct device *dev);
 #endif /* __ND_H__ */

drivers/nvdimm/pfn_devs.c

@@ -452,7 +452,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig)
 	unsigned long align, start_pad;
 	struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
 	struct nd_namespace_common *ndns = nd_pfn->ndns;
-	const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev);
+	const uuid_t *parent_uuid = nd_dev_to_uuid(&ndns->dev);
 
 	if (!pfn_sb || !ndns)
 		return -ENODEV;

include/linux/nd.h

@@ -88,7 +88,7 @@ struct nd_namespace_pmem {
 	struct nd_namespace_io nsio;
 	unsigned long lbasize;
 	char *alt_name;
-	u8 *uuid;
+	uuid_t *uuid;
 	int id;
 };
 
@@ -105,7 +105,7 @@ struct nd_namespace_pmem {
 struct nd_namespace_blk {
 	struct nd_namespace_common common;
 	char *alt_name;
-	u8 *uuid;
+	uuid_t *uuid;
 	int id;
 	unsigned long lbasize;
 	resource_size_t size;