[dm-devel] [PATCH 3/4] dm-zoned: V2 metadata handling

[Hannes Reinecke]

Add 'V2' metadata which includes UUIDs for the dmz set and for
the device itself.

Signed-off-by: Hannes Reinecke <hare at suse.de>
---
 drivers/md/dm-zoned-metadata.c | 80 +++++++++++++++++++++++++++++++++---------
 drivers/md/dm-zoned-target.c   |  2 +-
 2 files changed, 64 insertions(+), 18 deletions(-)

diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index dc1d17bc3bbb..026f285fba33 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -16,7 +16,8 @@
 /*
  * Metadata version.
  */
-#define DMZ_META_VER	1
+#define DMZ_META_COMPAT_VER 1
+#define DMZ_META_VER	2
 
 /*
  * On-disk super block magic.
@@ -69,8 +70,17 @@ struct dmz_super {
 	/* Checksum */
 	__le32		crc;			/*  48 */
 
-	/* Padding to full 512B sector */
-	u8		reserved[464];		/* 512 */
+	/* DM-Zoned label */
+	u8		dmz_label[32];		/*  80 */
+
+	/* DM-Zoned UUID */
+	u8		dmz_uuid[16];		/*  96 */
+
+	/* Device UUID */
+	u8		dev_uuid[16];		/* 112 */
+
+	/* Padding to full 512B - CRC sector */
+	u8		reserved[400];		/* 512 */
 };
 
 /*
@@ -133,6 +143,10 @@ struct dmz_sb {
 struct dmz_metadata {
 	struct dmz_dev		*dev;
 
+	char			dmz_label[BDEVNAME_SIZE];
+	uuid_t			dmz_uuid;
+	uuid_t			dev_uuid;
+
 	sector_t		zone_bitmap_size;
 	unsigned int		zone_nr_bitmap_blocks;
 	unsigned int		zone_bits_per_mblk;
@@ -659,7 +673,14 @@ static int dmz_write_sb(struct dmz_metadata *zmd, unsigned int set)
 	int ret;
 
 	sb->magic = cpu_to_le32(DMZ_MAGIC);
-	sb->version = cpu_to_le32(DMZ_META_VER);
+
+	if (!uuid_is_null(&zmd->dmz_uuid)) {
+		sb->version = cpu_to_le32(DMZ_META_VER);
+		uuid_copy((uuid_t *)sb->dmz_uuid, &zmd->dmz_uuid);
+		memcpy(sb->dmz_label, zmd->dmz_label, BDEVNAME_SIZE);
+		uuid_copy((uuid_t *)sb->dev_uuid, &zmd->dev_uuid);
+	} else
+		sb->version = cpu_to_le32(DMZ_META_COMPAT_VER);
 
 	sb->gen = cpu_to_le64(sb_gen);
 
@@ -848,28 +869,29 @@ static int dmz_check_sb(struct dmz_metadata *zmd, struct dmz_super *sb)
 {
 	unsigned int nr_meta_zones, nr_data_zones;
 	struct dmz_dev *dev = zmd->dev;
-	u32 crc, stored_crc;
+	u32 crc, stored_crc, dmz_version;
 	u64 gen;
 
-	gen = le64_to_cpu(sb->gen);
-	stored_crc = le32_to_cpu(sb->crc);
-	sb->crc = 0;
-	crc = crc32_le(gen, (unsigned char *)sb, DMZ_BLOCK_SIZE);
-	if (crc != stored_crc) {
-		dmz_dev_err(dev, "Invalid checksum (needed 0x%08x, got 0x%08x)",
-			    crc, stored_crc);
-		return -ENXIO;
-	}
-
 	if (le32_to_cpu(sb->magic) != DMZ_MAGIC) {
 		dmz_dev_err(dev, "Invalid meta magic (needed 0x%08x, got 0x%08x)",
 			    DMZ_MAGIC, le32_to_cpu(sb->magic));
 		return -ENXIO;
 	}
 
-	if (le32_to_cpu(sb->version) != DMZ_META_VER) {
+	dmz_version = le32_to_cpu(sb->version);
+	if (dmz_version > DMZ_META_VER) {
 		dmz_dev_err(dev, "Invalid meta version (needed %d, got %d)",
-			    DMZ_META_VER, le32_to_cpu(sb->version));
+			    DMZ_META_VER, dmz_version);
+		return -ENXIO;
+	}
+
+	gen = le64_to_cpu(sb->gen);
+	stored_crc = le32_to_cpu(sb->crc);
+	sb->crc = 0;
+	crc = crc32_le(gen, (unsigned char *)sb, DMZ_BLOCK_SIZE);
+	if (crc != stored_crc) {
+		dmz_dev_err(dev, "Invalid checksum (needed 0x%08x, got 0x%08x)",
+			    crc, stored_crc);
 		return -ENXIO;
 	}
 
@@ -895,6 +917,21 @@ static int dmz_check_sb(struct dmz_metadata *zmd, struct dmz_super *sb)
 		return -ENXIO;
 	}
 
+	if (dmz_version == DMZ_META_VER) {
+		if (uuid_is_null((uuid_t *)sb->dmz_uuid)) {
+			dmz_dev_err(dev, "NULL DM-Zoned uuid");
+			return -ENXIO;
+		}
+		uuid_copy(&zmd->dmz_uuid, (uuid_t *)sb->dmz_uuid);
+		memcpy(zmd->dmz_label, sb->dmz_label, BDEVNAME_SIZE);
+		if (uuid_is_null((uuid_t *)sb->dev_uuid)) {
+			dmz_dev_err(dev, "NULL device uuid");
+			return -ENXIO;
+		}
+		uuid_copy(&zmd->dev_uuid, (uuid_t *)sb->dev_uuid);
+
+	}
+
 	/* OK */
 	zmd->nr_meta_blocks = le32_to_cpu(sb->nr_meta_blocks);
 	zmd->nr_reserved_seq = le32_to_cpu(sb->nr_reserved_seq);
@@ -2460,9 +2497,18 @@ int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **metadata)
 		goto err;
 	}
 
+	dmz_dev_info(dev, "DM-Zoned version %d",
+		     uuid_is_null(&zmd->dmz_uuid) ?
+		     DMZ_META_COMPAT_VER : DMZ_META_VER);
+	if (!uuid_is_null(&zmd->dmz_uuid))
+		dmz_dev_info(dev, "DM UUID %pUl", &zmd->dmz_uuid);
+	if (strlen(zmd->dmz_label))
+		dmz_dev_info(dev, "DM Label %s", zmd->dmz_label);
 	dmz_dev_info(dev, "Host-%s zoned block device",
 		     bdev_zoned_model(dev->bdev) == BLK_ZONED_HA ?
 		     "aware" : "managed");
+	if (!uuid_is_null(&zmd->dev_uuid))
+		dmz_dev_info(dev, "  uuid %pUl", &zmd->dev_uuid);
 	dmz_dev_info(dev, "  %llu 512-byte logical sectors",
 		     (u64)dev->capacity);
 	dmz_dev_info(dev, "  %u zones of %llu 512-byte logical sectors",
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index 44e30a7de8b9..7ec9dde24516 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -1008,7 +1008,7 @@ static int dmz_message(struct dm_target *ti, unsigned int argc, char **argv,
 
 static struct target_type dmz_type = {
 	.name		 = "zoned",
-	.version	 = {1, 1, 0},
+	.version	 = {1, 2, 0},
 	.features	 = DM_TARGET_SINGLETON | DM_TARGET_ZONED_HM,
 	.module		 = THIS_MODULE,
 	.ctr		 = dmz_ctr,
-- 
2.16.4