dm zoned: metadata version 2

Implement handling for metadata version 2. The new metadata adds a
label and UUID for the device mapper device, and additional UUID for
the underlying block devices.

It also allows for an additional regular drive to be used for
emulating random access zones. The emulated zones will be placed
logically in front of the zones from the zoned block device, causing
the superblocks and metadata to be stored on that device.

The first zone of the original zoned device will be used to hold
another, tertiary copy of the metadata; this copy carries a generation
number of 0 and is never updated; it's just used for identification.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Bob Liu <bob.liu@oracle.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 134 insertions, 51 deletions

diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index a09fb78ffe88..ea43f6892ced 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -13,6 +13,8 @@
 
 #define DMZ_MIN_BIOS		8192
 
+#define DMZ_MAX_DEVS		2
+
 /*
  * Zone BIO context.
  */
@@ -38,7 +40,7 @@ struct dm_chunk_work {
  * Target descriptor.
  */
 struct dmz_target {
-	struct dm_dev		*ddev;
+	struct dm_dev		*ddev[DMZ_MAX_DEVS];
 
 	unsigned long		flags;
 
@@ -81,7 +83,7 @@ static inline void dmz_bio_endio(struct bio *bio, blk_status_t status)
 
 	if (status != BLK_STS_OK && bio->bi_status == BLK_STS_OK)
 		bio->bi_status = status;
-	if (bio->bi_status != BLK_STS_OK)
+	if (bioctx->dev && bio->bi_status != BLK_STS_OK)
 		bioctx->dev->flags |= DMZ_CHECK_BDEV;
 
 	if (refcount_dec_and_test(&bioctx->ref)) {
@@ -690,60 +692,64 @@ static int dmz_map(struct dm_target *ti, struct bio *bio)
 /*
  * Get zoned device information.
  */
-static int dmz_get_zoned_device(struct dm_target *ti, char *path)
+static int dmz_get_zoned_device(struct dm_target *ti, char *path,
+				int idx, int nr_devs)
 {
 	struct dmz_target *dmz = ti->private;
-	struct request_queue *q;
+	struct dm_dev *ddev;
 	struct dmz_dev *dev;
-	sector_t aligned_capacity;
 	int ret;
+	struct block_device *bdev;
 
 	/* Get the target device */
-	ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &dmz->ddev);
+	ret = dm_get_device(ti, path, dm_table_get_mode(ti->table), &ddev);
 	if (ret) {
 		ti->error = "Get target device failed";
-		dmz->ddev = NULL;
 		return ret;
 	}
 
-	dev = kzalloc(sizeof(struct dmz_dev), GFP_KERNEL);
-	if (!dev) {
-		ret = -ENOMEM;
-		goto err;
+	bdev = ddev->bdev;
+	if (bdev_zoned_model(bdev) == BLK_ZONED_NONE) {
+		if (nr_devs == 1) {
+			ti->error = "Invalid regular device";
+			goto err;
+		}
+		if (idx != 0) {
+			ti->error = "First device must be a regular device";
+			goto err;
+		}
+		if (dmz->ddev[0]) {
+			ti->error = "Too many regular devices";
+			goto err;
+		}
+		dev = &dmz->dev[idx];
+		dev->flags = DMZ_BDEV_REGULAR;
+	} else {
+		if (dmz->ddev[idx]) {
+			ti->error = "Too many zoned devices";
+			goto err;
+		}
+		if (nr_devs > 1 && idx == 0) {
+			ti->error = "First device must be a regular device";
+			goto err;
+		}
+		dev = &dmz->dev[idx];
 	}
-
-	dev->bdev = dmz->ddev->bdev;
+	dev->bdev = bdev;
 	(void)bdevname(dev->bdev, dev->name);
 
-	if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE) {
-		ti->error = "Not a zoned block device";
-		ret = -EINVAL;
-		goto err;
-	}
-
-	q = bdev_get_queue(dev->bdev);
-	dev->capacity = i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT;
-	aligned_capacity = dev->capacity &
-				~((sector_t)blk_queue_zone_sectors(q) - 1);
-	if (ti->begin ||
-	    ((ti->len != dev->capacity) && (ti->len != aligned_capacity))) {
-		ti->error = "Partial mapping not supported";
-		ret = -EINVAL;
+	dev->capacity = i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
+	if (ti->begin) {
+		ti->error = "Partial mapping is not supported";
 		goto err;
 	}
 
-	dev->zone_nr_sectors = blk_queue_zone_sectors(q);
-
-	dev->nr_zones = blkdev_nr_zones(dev->bdev->bd_disk);
-
-	dmz->dev = dev;
+	dmz->ddev[idx] = ddev;
 
 	return 0;
 err:
-	dm_put_device(ti, dmz->ddev);
-	kfree(dev);
-
-	return ret;
+	dm_put_device(ti, ddev);
+	return -EINVAL;
 }
 
 /*
@@ -752,10 +758,56 @@ err:
 static void dmz_put_zoned_device(struct dm_target *ti)
 {
 	struct dmz_target *dmz = ti->private;
+	int i;
 
-	dm_put_device(ti, dmz->ddev);
-	kfree(dmz->dev);
-	dmz->dev = NULL;
+	for (i = 0; i < DMZ_MAX_DEVS; i++) {
+		if (dmz->ddev[i]) {
+			dm_put_device(ti, dmz->ddev[i]);
+			dmz->ddev[i] = NULL;
+		}
+	}
+}
+
+static int dmz_fixup_devices(struct dm_target *ti)
+{
+	struct dmz_target *dmz = ti->private;
+	struct dmz_dev *reg_dev, *zoned_dev;
+	struct request_queue *q;
+
+	/*
+	 * When we have two devices, the first one must be a regular block
+	 * device and the second a zoned block device.
+	 */
+	if (dmz->ddev[0] && dmz->ddev[1]) {
+		reg_dev = &dmz->dev[0];
+		if (!(reg_dev->flags & DMZ_BDEV_REGULAR)) {
+			ti->error = "Primary disk is not a regular device";
+			return -EINVAL;
+		}
+		zoned_dev = &dmz->dev[1];
+		if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
+			ti->error = "Secondary disk is not a zoned device";
+			return -EINVAL;
+		}
+	} else {
+		reg_dev = NULL;
+		zoned_dev = &dmz->dev[0];
+		if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
+			ti->error = "Disk is not a zoned device";
+			return -EINVAL;
+		}
+	}
+	q = bdev_get_queue(zoned_dev->bdev);
+	zoned_dev->zone_nr_sectors = blk_queue_zone_sectors(q);
+	zoned_dev->nr_zones = blkdev_nr_zones(zoned_dev->bdev->bd_disk);
+
+	if (reg_dev) {
+		reg_dev->zone_nr_sectors = zoned_dev->zone_nr_sectors;
+		reg_dev->nr_zones = DIV_ROUND_UP(reg_dev->capacity,
+						 reg_dev->zone_nr_sectors);
+		zoned_dev->zone_offset = reg_dev->nr_zones;
+	}
+	return 0;
 }
 
 /*
@@ -764,11 +816,10 @@ static void dmz_put_zoned_device(struct dm_target *ti)
 static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
 	struct dmz_target *dmz;
-	struct dmz_dev *dev;
 	int ret;
 
 	/* Check arguments */
-	if (argc != 1) {
+	if (argc < 1 || argc > 2) {
 		ti->error = "Invalid argument count";
 		return -EINVAL;
 	}
@@ -779,18 +830,34 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		ti->error = "Unable to allocate the zoned target descriptor";
 		return -ENOMEM;
 	}
+	dmz->dev = kcalloc(2, sizeof(struct dmz_dev), GFP_KERNEL);
+	if (!dmz->dev) {
+		ti->error = "Unable to allocate the zoned device descriptors";
+		kfree(dmz);
+		return -ENOMEM;
+	}
 	ti->private = dmz;
 
 	/* Get the target zoned block device */
-	ret = dmz_get_zoned_device(ti, argv[0]);
+	ret = dmz_get_zoned_device(ti, argv[0], 0, argc);
+	if (ret)
+		goto err;
+
+	if (argc == 2) {
+		ret = dmz_get_zoned_device(ti, argv[1], 1, argc);
+		if (ret) {
+			dmz_put_zoned_device(ti);
+			goto err;
+		}
+	}
+	ret = dmz_fixup_devices(ti);
 	if (ret) {
-		dmz->ddev = NULL;
+		dmz_put_zoned_device(ti);
 		goto err;
 	}
 
 	/* Initialize metadata */
-	dev = dmz->dev;
-	ret = dmz_ctr_metadata(dev, &dmz->metadata,
+	ret = dmz_ctr_metadata(dmz->dev, argc, &dmz->metadata,
 			       dm_table_device_name(ti->table));
 	if (ret) {
 		ti->error = "Metadata initialization failed";
@@ -867,6 +934,7 @@ err_meta:
 err_dev:
 	dmz_put_zoned_device(ti);
 err:
+	kfree(dmz->dev);
 	kfree(dmz);
 
 	return ret;
@@ -897,6 +965,7 @@ static void dmz_dtr(struct dm_target *ti)
 
 	mutex_destroy(&dmz->chunk_lock);
 
+	kfree(dmz->dev);
 	kfree(dmz);
 }
 
@@ -971,10 +1040,17 @@ static int dmz_iterate_devices(struct dm_target *ti,
 			       iterate_devices_callout_fn fn, void *data)
 {
 	struct dmz_target *dmz = ti->private;
-	struct dmz_dev *dev = dmz->dev;
-	sector_t capacity = dev->capacity & ~(dmz_zone_nr_sectors(dmz->metadata) - 1);
-
-	return fn(ti, dmz->ddev, 0, capacity, data);
+	unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
+	sector_t capacity;
+	int r;
+
+	capacity = dmz->dev[0].capacity & ~(zone_nr_sectors - 1);
+	r = fn(ti, dmz->ddev[0], 0, capacity, data);
+	if (!r && dmz->ddev[1]) {
+		capacity = dmz->dev[1].capacity & ~(zone_nr_sectors - 1);
+		r = fn(ti, dmz->ddev[1], 0, capacity, data);
+	}
+	return r;
 }
 
 static void dmz_status(struct dm_target *ti, status_type_t type,
@@ -984,6 +1060,7 @@ static void dmz_status(struct dm_target *ti, status_type_t type,
 	struct dmz_target *dmz = ti->private;
 	ssize_t sz = 0;
 	char buf[BDEVNAME_SIZE];
+	struct dmz_dev *dev;
 
 	switch (type) {
 	case STATUSTYPE_INFO:
@@ -995,8 +1072,14 @@ static void dmz_status(struct dm_target *ti, status_type_t type,
 		       dmz_nr_seq_zones(dmz->metadata));
 		break;
 	case STATUSTYPE_TABLE:
-		format_dev_t(buf, dmz->dev->bdev->bd_dev);
+		dev = &dmz->dev[0];
+		format_dev_t(buf, dev->bdev->bd_dev);
 		DMEMIT("%s", buf);
+		if (dmz->dev[1].bdev) {
+			dev = &dmz->dev[1];
+			format_dev_t(buf, dev->bdev->bd_dev);
+			DMEMIT(" %s", buf);
+		}
 		break;
 	}
 	return;
@@ -1018,7 +1101,7 @@ 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	 = {2, 0, 0},
 	.features	 = DM_TARGET_SINGLETON | DM_TARGET_ZONED_HM,
 	.module		 = THIS_MODULE,
 	.ctr		 = dmz_ctr,