dm zoned: support arbitrary number of devices

Remove the hard-coded limit of two devices and support an unlimited
number of additional zoned devices.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

1 files changed, 60 insertions, 44 deletions

diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index aa3d26d16441..fc30c78dffdb 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -13,8 +13,6 @@
 
 #define DMZ_MIN_BIOS		8192
 
-#define DMZ_MAX_DEVS		2
-
 /*
  * Zone BIO context.
  */
@@ -40,10 +38,10 @@ struct dm_chunk_work {
  * Target descriptor.
  */
 struct dmz_target {
-	struct dm_dev		*ddev[DMZ_MAX_DEVS];
+	struct dm_dev		**ddev;
 	unsigned int		nr_ddevs;
 
-	unsigned long		flags;
+	unsigned int		flags;
 
 	/* Zoned block device information */
 	struct dmz_dev		*dev;
@@ -764,7 +762,7 @@ static void dmz_put_zoned_device(struct dm_target *ti)
 	struct dmz_target *dmz = ti->private;
 	int i;
 
-	for (i = 0; i < DMZ_MAX_DEVS; i++) {
+	for (i = 0; i < dmz->nr_ddevs; i++) {
 		if (dmz->ddev[i]) {
 			dm_put_device(ti, dmz->ddev[i]);
 			dmz->ddev[i] = NULL;
@@ -777,21 +775,35 @@ 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;
+	sector_t zone_nr_sectors = 0;
+	int i;
 
 	/*
-	 * When we have two devices, the first one must be a regular block
-	 * device and the second a zoned block device.
+	 * When we have more than on devices, the first one must be a
+	 * regular block device and the others zoned block devices.
 	 */
-	if (dmz->ddev[0] && dmz->ddev[1]) {
+	if (dmz->nr_ddevs > 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;
+		for (i = 1; i < dmz->nr_ddevs; i++) {
+			zoned_dev = &dmz->dev[i];
+			if (zoned_dev->flags & DMZ_BDEV_REGULAR) {
+				ti->error = "Secondary disk is not a zoned device";
+				return -EINVAL;
+			}
+			q = bdev_get_queue(zoned_dev->bdev);
+			if (zone_nr_sectors &&
+			    zone_nr_sectors != blk_queue_zone_sectors(q)) {
+				ti->error = "Zone nr sectors mismatch";
+				return -EINVAL;
+			}
+			zone_nr_sectors = blk_queue_zone_sectors(q);
+			zoned_dev->zone_nr_sectors = zone_nr_sectors;
+			zoned_dev->nr_zones =
+				blkdev_nr_zones(zoned_dev->bdev->bd_disk);
 		}
 	} else {
 		reg_dev = NULL;
@@ -800,17 +812,24 @@ static int dmz_fixup_devices(struct dm_target *ti)
 			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);
 	}
-	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;
+		sector_t zone_offset;
+
+		reg_dev->zone_nr_sectors = zone_nr_sectors;
 		reg_dev->nr_zones =
 			DIV_ROUND_UP_SECTOR_T(reg_dev->capacity,
 					      reg_dev->zone_nr_sectors);
-		zoned_dev->zone_offset = reg_dev->nr_zones;
+		reg_dev->zone_offset = 0;
+		zone_offset = reg_dev->nr_zones;
+		for (i = 1; i < dmz->nr_ddevs; i++) {
+			dmz->dev[i].zone_offset = zone_offset;
+			zone_offset += dmz->dev[i].nr_zones;
+		}
 	}
 	return 0;
 }
@@ -824,7 +843,7 @@ static int dmz_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	int ret, i;
 
 	/* Check arguments */
-	if (argc < 1 || argc > 2) {
+	if (argc < 1) {
 		ti->error = "Invalid argument count";
 		return -EINVAL;
 	}
@@ -835,32 +854,31 @@ 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);
+	dmz->dev = kcalloc(argc, sizeof(struct dmz_dev), GFP_KERNEL);
 	if (!dmz->dev) {
 		ti->error = "Unable to allocate the zoned device descriptors";
 		kfree(dmz);
 		return -ENOMEM;
 	}
+	dmz->ddev = kcalloc(argc, sizeof(struct dm_dev *), GFP_KERNEL);
+	if (!dmz->ddev) {
+		ti->error = "Unable to allocate the dm device descriptors";
+		ret = -ENOMEM;
+		goto err;
+	}
 	dmz->nr_ddevs = argc;
+
 	ti->private = dmz;
 
 	/* Get the target zoned block device */
-	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;
-		}
+	for (i = 0; i < argc; i++) {
+		ret = dmz_get_zoned_device(ti, argv[i], i, argc);
+		if (ret)
+			goto err_dev;
 	}
 	ret = dmz_fixup_devices(ti);
-	if (ret) {
-		dmz_put_zoned_device(ti);
-		goto err;
-	}
+	if (ret)
+		goto err_dev;
 
 	/* Initialize metadata */
 	ret = dmz_ctr_metadata(dmz->dev, argc, &dmz->metadata,
@@ -1056,13 +1074,13 @@ static int dmz_iterate_devices(struct dm_target *ti,
 	struct dmz_target *dmz = ti->private;
 	unsigned int zone_nr_sectors = dmz_zone_nr_sectors(dmz->metadata);
 	sector_t capacity;
-	int r;
+	int i, 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);
+	for (i = 0; i < dmz->nr_ddevs; i++) {
+		capacity = dmz->dev[i].capacity & ~(zone_nr_sectors - 1);
+		r = fn(ti, dmz->ddev[i], 0, capacity, data);
+		if (r)
+			break;
 	}
 	return r;
 }
@@ -1083,9 +1101,7 @@ static void dmz_status(struct dm_target *ti, status_type_t type,
 		       dmz_nr_zones(dmz->metadata),
 		       dmz_nr_unmap_cache_zones(dmz->metadata),
 		       dmz_nr_cache_zones(dmz->metadata));
-		for (i = 0; i < DMZ_MAX_DEVS; i++) {
-			if (!dmz->ddev[i])
-				continue;
+		for (i = 0; i < dmz->nr_ddevs; i++) {
 			/*
 			 * For a multi-device setup the first device
 			 * contains only cache zones.
@@ -1104,8 +1120,8 @@ static void dmz_status(struct dm_target *ti, status_type_t type,
 		dev = &dmz->dev[0];
 		format_dev_t(buf, dev->bdev->bd_dev);
 		DMEMIT("%s", buf);
-		if (dmz->dev[1].bdev) {
-			dev = &dmz->dev[1];
+		for (i = 1; i < dmz->nr_ddevs; i++) {
+			dev = &dmz->dev[i];
 			format_dev_t(buf, dev->bdev->bd_dev);
 			DMEMIT(" %s", buf);
 		}