[PATCH 03/13] dm-zoned: use array for superblock zones

[Hannes Reinecke <hare@suse.de>]

Instead of storing just the first superblock zone and calculate
the secondary relative to that we should be using an array for
holding the superblock zones.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
---
 drivers/md/dm-zoned-metadata.c | 41 +++++++++++++++++++++++++----------------
 1 file changed, 25 insertions(+), 16 deletions(-)

diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 1993eeb26bc1..900b1c1224f5 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -124,6 +124,7 @@ struct dmz_sb {
 	sector_t		block;
 	struct dmz_mblock	*mblk;
 	struct dmz_super	*sb;
+	struct dm_zone		*zone;
 };
 
 /*
@@ -150,7 +151,6 @@ struct dmz_metadata {
 	/* Zone information array */
 	struct dm_zone		*zones;
 
-	struct dm_zone		*sb_zone;
 	struct dmz_sb		sb[2];
 	unsigned int		mblk_primary;
 	u64			sb_gen;
@@ -839,8 +839,9 @@ int dmz_flush_metadata(struct dmz_metadata *zmd)
 /*
  * Check super block.
  */
-static int dmz_check_sb(struct dmz_metadata *zmd, struct dmz_super *sb)
+static int dmz_check_sb(struct dmz_metadata *zmd, unsigned int set)
 {
+	struct dmz_super *sb = zmd->sb[set].sb;
 	unsigned int nr_meta_zones, nr_data_zones;
 	struct dmz_dev *dev = zmd->dev;
 	u32 crc, stored_crc;
@@ -932,16 +933,20 @@ static int dmz_lookup_secondary_sb(struct dmz_metadata *zmd)
 
 	/* Bad first super block: search for the second one */
 	zmd->sb[1].block = zmd->sb[0].block + zone_nr_blocks;
+	zmd->sb[1].zone = zmd->sb[0].zone + 1;
 	for (i = 0; i < zmd->nr_rnd_zones - 1; i++) {
 		if (dmz_read_sb(zmd, 1) != 0)
 			break;
-		if (le32_to_cpu(zmd->sb[1].sb->magic) == DMZ_MAGIC)
+		if (le32_to_cpu(zmd->sb[1].sb->magic) == DMZ_MAGIC) {
+			zmd->sb[1].zone += i;
 			return 0;
+		}
 		zmd->sb[1].block += zone_nr_blocks;
 	}
 
 	dmz_free_mblock(zmd, mblk);
 	zmd->sb[1].mblk = NULL;
+	zmd->sb[1].zone = NULL;
 
 	return -EIO;
 }
@@ -985,11 +990,9 @@ static int dmz_recover_mblocks(struct dmz_metadata *zmd, unsigned int dst_set)
 	dmz_dev_warn(zmd->dev, "Metadata set %u invalid: recovering", dst_set);
 
 	if (dst_set == 0)
-		zmd->sb[0].block = dmz_start_block(zmd, zmd->sb_zone);
-	else {
-		zmd->sb[1].block = zmd->sb[0].block +
-			(zmd->nr_meta_zones << zmd->dev->zone_nr_blocks_shift);
-	}
+		zmd->sb[0].block = dmz_start_block(zmd, zmd->sb[0].zone);
+	else
+		zmd->sb[1].block = dmz_start_block(zmd, zmd->sb[1].zone);
 
 	page = alloc_page(GFP_NOIO);
 	if (!page)
@@ -1033,21 +1036,27 @@ static int dmz_load_sb(struct dmz_metadata *zmd)
 	u64 sb_gen[2] = {0, 0};
 	int ret;
 
+	if (!zmd->sb[0].zone) {
+		dmz_dev_err(zmd->dev, "Primary super block zone not set");
+		return -ENXIO;
+	}
+
 	/* Read and check the primary super block */
-	zmd->sb[0].block = dmz_start_block(zmd, zmd->sb_zone);
+	zmd->sb[0].block = dmz_start_block(zmd, zmd->sb[0].zone);
 	ret = dmz_get_sb(zmd, 0);
 	if (ret) {
 		dmz_dev_err(zmd->dev, "Read primary super block failed");
 		return ret;
 	}
 
-	ret = dmz_check_sb(zmd, zmd->sb[0].sb);
+	ret = dmz_check_sb(zmd, 0);
 
 	/* Read and check secondary super block */
 	if (ret == 0) {
 		sb_good[0] = true;
-		zmd->sb[1].block = zmd->sb[0].block +
-			(zmd->nr_meta_zones << zmd->dev->zone_nr_blocks_shift);
+		if (!zmd->sb[1].zone)
+			zmd->sb[1].zone = zmd->sb[0].zone + zmd->nr_meta_zones;
+		zmd->sb[1].block = dmz_start_block(zmd, zmd->sb[1].zone);
 		ret = dmz_get_sb(zmd, 1);
 	} else
 		ret = dmz_lookup_secondary_sb(zmd);
@@ -1057,7 +1066,7 @@ static int dmz_load_sb(struct dmz_metadata *zmd)
 		return ret;
 	}
 
-	ret = dmz_check_sb(zmd, zmd->sb[1].sb);
+	ret = dmz_check_sb(zmd, 1);
 	if (ret == 0)
 		sb_good[1] = true;
 
@@ -1142,9 +1151,9 @@ static int dmz_init_zone(struct blk_zone *blkz, unsigned int idx, void *data)
 		zmd->nr_useable_zones++;
 		if (dmz_is_rnd(zone)) {
 			zmd->nr_rnd_zones++;
-			if (!zmd->sb_zone) {
+			if (!zmd->sb[0].zone) {
 				/* Super block zone */
-				zmd->sb_zone = zone;
+				zmd->sb[0].zone = zone;
 			}
 		}
 	}
@@ -2415,7 +2424,7 @@ int dmz_ctr_metadata(struct dmz_dev *dev, struct dmz_metadata **metadata)
 
 	/* Set metadata zones starting from sb_zone */
 	for (i = 0; i < zmd->nr_meta_zones << 1; i++) {
-		zone = dmz_get(zmd, zmd->sb_zone->id + i);
+		zone = dmz_get(zmd, zmd->sb[0].zone->id + i);
 		if (!dmz_is_rnd(zone))
 			goto err;
 		set_bit(DMZ_META, &zone->flags);
-- 
2.16.4