Merge tag 'for-5.5/zoned-20191122' of git://git.kernel.dk/linux-block

Pull zoned block device update from Jens Axboe:
 "Enhancements and improvements to the zoned device support"

* tag 'for-5.5/zoned-20191122' of git://git.kernel.dk/linux-block:
  scsi: sd_zbc: Remove set but not used variable 'buflen'
  block: rework zone reporting
  scsi: sd_zbc: Cleanup sd_zbc_alloc_report_buffer()
  null_blk: Add zone_nr_conv to features
  null_blk: clean up report zones
  null_blk: clean up the block device operations
  block: Remove partition support for zoned block devices
  block: Simplify report zones execution
  block: cleanup the !zoned case in blk_revalidate_disk_zones
  block: Enhance blk_revalidate_disk_zones()

9 files changed, 229 insertions, 374 deletions

diff --git a/drivers/block/null_blk.h b/drivers/block/null_blk.h
index 93c2a3d403da..bc837862b767 100644
--- a/drivers/block/null_blk.h
+++ b/drivers/block/null_blk.h
@@ -91,8 +91,8 @@ struct nullb {
 #ifdef CONFIG_BLK_DEV_ZONED
 int null_zone_init(struct nullb_device *dev);
 void null_zone_exit(struct nullb_device *dev);
-int null_zone_report(struct gendisk *disk, sector_t sector,
-		     struct blk_zone *zones, unsigned int *nr_zones);
+int null_report_zones(struct gendisk *disk, sector_t sector,
+		      unsigned int nr_zones, report_zones_cb cb, void *data);
 blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
 				enum req_opf op, sector_t sector,
 				sector_t nr_sectors);
@@ -105,12 +105,6 @@ static inline int null_zone_init(struct nullb_device *dev)
 	return -EINVAL;
 }
 static inline void null_zone_exit(struct nullb_device *dev) {}
-static inline int null_zone_report(struct gendisk *disk, sector_t sector,
-				   struct blk_zone *zones,
-				   unsigned int *nr_zones)
-{
-	return -EOPNOTSUPP;
-}
 static inline blk_status_t null_handle_zoned(struct nullb_cmd *cmd,
 					     enum req_opf op, sector_t sector,
 					     sector_t nr_sectors)
@@ -123,5 +117,6 @@ static inline size_t null_zone_valid_read_len(struct nullb *nullb,
 {
 	return len;
 }
+#define null_report_zones	NULL
 #endif /* CONFIG_BLK_DEV_ZONED */
 #endif /* __NULL_BLK_H */
diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index ea7a4d6b7848..795fda576824 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -493,7 +493,7 @@ nullb_group_drop_item(struct config_group *group, struct config_item *item)
 
 static ssize_t memb_group_features_show(struct config_item *item, char *page)
 {
-	return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size\n");
+	return snprintf(page, PAGE_SIZE, "memory_backed,discard,bandwidth,cache,badblocks,zoned,zone_size,zone_nr_conv\n");
 }
 
 CONFIGFS_ATTR_RO(memb_group_, features);
@@ -1468,20 +1468,9 @@ static void null_config_discard(struct nullb *nullb)
 	blk_queue_flag_set(QUEUE_FLAG_DISCARD, nullb->q);
 }
 
-static int null_open(struct block_device *bdev, fmode_t mode)
-{
-	return 0;
-}
-
-static void null_release(struct gendisk *disk, fmode_t mode)
-{
-}
-
-static const struct block_device_operations null_fops = {
-	.owner =	THIS_MODULE,
-	.open =		null_open,
-	.release =	null_release,
-	.report_zones =	null_zone_report,
+static const struct block_device_operations null_ops = {
+	.owner		= THIS_MODULE,
+	.report_zones	= null_report_zones,
 };
 
 static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
@@ -1582,7 +1571,7 @@ static int null_gendisk_register(struct nullb *nullb)
 	disk->flags |= GENHD_FL_EXT_DEVT | GENHD_FL_SUPPRESS_PARTITION_INFO;
 	disk->major		= null_major;
 	disk->first_minor	= nullb->index;
-	disk->fops		= &null_fops;
+	disk->fops		= &null_ops;
 	disk->private_data	= nullb;
 	disk->queue		= nullb->q;
 	strncpy(disk->disk_name, nullb->disk_name, DISK_NAME_LEN);
diff --git a/drivers/block/null_blk_zoned.c b/drivers/block/null_blk_zoned.c
index 02f41a3bc4cb..d4d88b581822 100644
--- a/drivers/block/null_blk_zoned.c
+++ b/drivers/block/null_blk_zoned.c
@@ -66,22 +66,35 @@ void null_zone_exit(struct nullb_device *dev)
 	kvfree(dev->zones);
 }
 
-int null_zone_report(struct gendisk *disk, sector_t sector,
-		     struct blk_zone *zones, unsigned int *nr_zones)
+int null_report_zones(struct gendisk *disk, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data)
 {
 	struct nullb *nullb = disk->private_data;
 	struct nullb_device *dev = nullb->dev;
-	unsigned int zno, nrz = 0;
+	unsigned int first_zone, i;
+	struct blk_zone zone;
+	int error;
 
-	zno = null_zone_no(dev, sector);
-	if (zno < dev->nr_zones) {
-		nrz = min_t(unsigned int, *nr_zones, dev->nr_zones - zno);
-		memcpy(zones, &dev->zones[zno], nrz * sizeof(struct blk_zone));
-	}
+	first_zone = null_zone_no(dev, sector);
+	if (first_zone >= dev->nr_zones)
+		return 0;
 
-	*nr_zones = nrz;
+	nr_zones = min(nr_zones, dev->nr_zones - first_zone);
+	for (i = 0; i < nr_zones; i++) {
+		/*
+		 * Stacked DM target drivers will remap the zone information by
+		 * modifying the zone information passed to the report callback.
+		 * So use a local copy to avoid corruption of the device zone
+		 * array.
+		 */
+		memcpy(&zone, &dev->zones[first_zone + i],
+		       sizeof(struct blk_zone));
+		error = cb(&zone, i, data);
+		if (error)
+			return error;
+	}
 
-	return 0;
+	return nr_zones;
 }
 
 size_t null_zone_valid_read_len(struct nullb *nullb,
diff --git a/drivers/md/dm-flakey.c b/drivers/md/dm-flakey.c
index 76587e9af0ef..a2cc9e45cbba 100644
--- a/drivers/md/dm-flakey.c
+++ b/drivers/md/dm-flakey.c
@@ -459,21 +459,15 @@ static int flakey_prepare_ioctl(struct dm_target *ti, struct block_device **bdev
 }
 
 #ifdef CONFIG_BLK_DEV_ZONED
-static int flakey_report_zones(struct dm_target *ti, sector_t sector,
-			       struct blk_zone *zones, unsigned int *nr_zones)
+static int flakey_report_zones(struct dm_target *ti,
+		struct dm_report_zones_args *args, unsigned int nr_zones)
 {
 	struct flakey_c *fc = ti->private;
-	int ret;
+	sector_t sector = flakey_map_sector(ti, args->next_sector);
 
-	/* Do report and remap it */
-	ret = blkdev_report_zones(fc->dev->bdev, flakey_map_sector(ti, sector),
-				  zones, nr_zones);
-	if (ret != 0)
-		return ret;
-
-	if (*nr_zones)
-		dm_remap_zone_report(ti, fc->start, zones, nr_zones);
-	return 0;
+	args->start = fc->start;
+	return blkdev_report_zones(fc->dev->bdev, sector, nr_zones,
+				   dm_report_zones_cb, args);
 }
 #endif
 
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 97acafd48c85..8d07fdf63a47 100644
--- a/drivers/md/dm-linear.c
+++ b/drivers/md/dm-linear.c
@@ -136,21 +136,15 @@ static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev
 }
 
 #ifdef CONFIG_BLK_DEV_ZONED
-static int linear_report_zones(struct dm_target *ti, sector_t sector,
-			       struct blk_zone *zones, unsigned int *nr_zones)
+static int linear_report_zones(struct dm_target *ti,
+		struct dm_report_zones_args *args, unsigned int nr_zones)
 {
-	struct linear_c *lc = (struct linear_c *) ti->private;
-	int ret;
-
-	/* Do report and remap it */
-	ret = blkdev_report_zones(lc->dev->bdev, linear_map_sector(ti, sector),
-				  zones, nr_zones);
-	if (ret != 0)
-		return ret;
+	struct linear_c *lc = ti->private;
+	sector_t sector = linear_map_sector(ti, args->next_sector);
 
-	if (*nr_zones)
-		dm_remap_zone_report(ti, lc->start, zones, nr_zones);
-	return 0;
+	args->start = lc->start;
+	return blkdev_report_zones(lc->dev->bdev, sector, nr_zones,
+				   dm_report_zones_cb, args);
 }
 #endif
 
diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index feb4718ce6a6..069e4675da6b 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -1080,9 +1080,10 @@ static int dmz_load_sb(struct dmz_metadata *zmd)
 /*
  * Initialize a zone descriptor.
  */
-static int dmz_init_zone(struct dmz_metadata *zmd, struct dm_zone *zone,
-			 struct blk_zone *blkz)
+static int dmz_init_zone(struct blk_zone *blkz, unsigned int idx, void *data)
 {
+	struct dmz_metadata *zmd = data;
+	struct dm_zone *zone = &zmd->zones[idx];
 	struct dmz_dev *dev = zmd->dev;
 
 	/* Ignore the eventual last runt (smaller) zone */
@@ -1096,26 +1097,29 @@ static int dmz_init_zone(struct dmz_metadata *zmd, struct dm_zone *zone,
 	atomic_set(&zone->refcount, 0);
 	zone->chunk = DMZ_MAP_UNMAPPED;
 
-	if (blkz->type == BLK_ZONE_TYPE_CONVENTIONAL) {
+	switch (blkz->type) {
+	case BLK_ZONE_TYPE_CONVENTIONAL:
 		set_bit(DMZ_RND, &zone->flags);
 		zmd->nr_rnd_zones++;
-	} else if (blkz->type == BLK_ZONE_TYPE_SEQWRITE_REQ ||
-		   blkz->type == BLK_ZONE_TYPE_SEQWRITE_PREF) {
+		break;
+	case BLK_ZONE_TYPE_SEQWRITE_REQ:
+	case BLK_ZONE_TYPE_SEQWRITE_PREF:
 		set_bit(DMZ_SEQ, &zone->flags);
-	} else
+		break;
+	default:
 		return -ENXIO;
-
-	if (blkz->cond == BLK_ZONE_COND_OFFLINE)
-		set_bit(DMZ_OFFLINE, &zone->flags);
-	else if (blkz->cond == BLK_ZONE_COND_READONLY)
-		set_bit(DMZ_READ_ONLY, &zone->flags);
+	}
 
 	if (dmz_is_rnd(zone))
 		zone->wp_block = 0;
 	else
 		zone->wp_block = dmz_sect2blk(blkz->wp - blkz->start);
 
-	if (!dmz_is_offline(zone) && !dmz_is_readonly(zone)) {
+	if (blkz->cond == BLK_ZONE_COND_OFFLINE)
+		set_bit(DMZ_OFFLINE, &zone->flags);
+	else if (blkz->cond == BLK_ZONE_COND_READONLY)
+		set_bit(DMZ_READ_ONLY, &zone->flags);
+	else {
 		zmd->nr_useable_zones++;
 		if (dmz_is_rnd(zone)) {
 			zmd->nr_rnd_zones++;
@@ -1139,23 +1143,13 @@ static void dmz_drop_zones(struct dmz_metadata *zmd)
 }
 
 /*
- * The size of a zone report in number of zones.
- * This results in 4096*64B=256KB report zones commands.
- */
-#define DMZ_REPORT_NR_ZONES	4096
-
-/*
  * Allocate and initialize zone descriptors using the zone
  * information from disk.
  */
 static int dmz_init_zones(struct dmz_metadata *zmd)
 {
 	struct dmz_dev *dev = zmd->dev;
-	struct dm_zone *zone;
-	struct blk_zone *blkz;
-	unsigned int nr_blkz;
-	sector_t sector = 0;
-	int i, ret = 0;
+	int ret;
 
 	/* Init */
 	zmd->zone_bitmap_size = dev->zone_nr_blocks >> 3;
@@ -1169,54 +1163,38 @@ static int dmz_init_zones(struct dmz_metadata *zmd)
 	dmz_dev_info(dev, "Using %zu B for zone information",
 		     sizeof(struct dm_zone) * dev->nr_zones);
 
-	/* Get zone information */
-	nr_blkz = DMZ_REPORT_NR_ZONES;
-	blkz = kcalloc(nr_blkz, sizeof(struct blk_zone), GFP_KERNEL);
-	if (!blkz) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
 	/*
-	 * Get zone information and initialize zone descriptors.
-	 * At the same time, determine where the super block
-	 * should be: first block of the first randomly writable
-	 * zone.
+	 * Get zone information and initialize zone descriptors.  At the same
+	 * time, determine where the super block should be: first block of the
+	 * first randomly writable zone.
 	 */
-	zone = zmd->zones;
-	while (sector < dev->capacity) {
-		/* Get zone information */
-		nr_blkz = DMZ_REPORT_NR_ZONES;
-		ret = blkdev_report_zones(dev->bdev, sector, blkz, &nr_blkz);
-		if (ret) {
-			dmz_dev_err(dev, "Report zones failed %d", ret);
-			goto out;
-		}
+	ret = blkdev_report_zones(dev->bdev, 0, BLK_ALL_ZONES, dmz_init_zone,
+				  zmd);
+	if (ret < 0) {
+		dmz_drop_zones(zmd);
+		return ret;
+	}
 
-		if (!nr_blkz)
-			break;
+	return 0;
+}
 
-		/* Process report */
-		for (i = 0; i < nr_blkz; i++) {
-			ret = dmz_init_zone(zmd, zone, &blkz[i]);
-			if (ret)
-				goto out;
-			sector += dev->zone_nr_sectors;
-			zone++;
-		}
-	}
+static int dmz_update_zone_cb(struct blk_zone *blkz, unsigned int idx,
+			      void *data)
+{
+	struct dm_zone *zone = data;
 
-	/* The entire zone configuration of the disk should now be known */
-	if (sector < dev->capacity) {
-		dmz_dev_err(dev, "Failed to get correct zone information");
-		ret = -ENXIO;
-	}
-out:
-	kfree(blkz);
-	if (ret)
-		dmz_drop_zones(zmd);
+	clear_bit(DMZ_OFFLINE, &zone->flags);
+	clear_bit(DMZ_READ_ONLY, &zone->flags);
+	if (blkz->cond == BLK_ZONE_COND_OFFLINE)
+		set_bit(DMZ_OFFLINE, &zone->flags);
+	else if (blkz->cond == BLK_ZONE_COND_READONLY)
+		set_bit(DMZ_READ_ONLY, &zone->flags);
 
-	return ret;
+	if (dmz_is_seq(zone))
+		zone->wp_block = dmz_sect2blk(blkz->wp - blkz->start);
+	else
+		zone->wp_block = 0;
+	return 0;
 }
 
 /*
@@ -1224,9 +1202,7 @@ out:
  */
 static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
 {
-	unsigned int nr_blkz = 1;
 	unsigned int noio_flag;
-	struct blk_zone blkz;
 	int ret;
 
 	/*
@@ -1236,29 +1212,18 @@ static int dmz_update_zone(struct dmz_metadata *zmd, struct dm_zone *zone)
 	 * GFP_NOIO was specified.
 	 */
 	noio_flag = memalloc_noio_save();
-	ret = blkdev_report_zones(zmd->dev->bdev, dmz_start_sect(zmd, zone),
-				  &blkz, &nr_blkz);
+	ret = blkdev_report_zones(zmd->dev->bdev, dmz_start_sect(zmd, zone), 1,
+				  dmz_update_zone_cb, zone);
 	memalloc_noio_restore(noio_flag);
-	if (!nr_blkz)
+
+	if (ret == 0)
 		ret = -EIO;
-	if (ret) {
+	if (ret < 0) {
 		dmz_dev_err(zmd->dev, "Get zone %u report failed",
 			    dmz_id(zmd, zone));
 		return ret;
 	}
 
-	clear_bit(DMZ_OFFLINE, &zone->flags);
-	clear_bit(DMZ_READ_ONLY, &zone->flags);
-	if (blkz.cond == BLK_ZONE_COND_OFFLINE)
-		set_bit(DMZ_OFFLINE, &zone->flags);
-	else if (blkz.cond == BLK_ZONE_COND_READONLY)
-		set_bit(DMZ_READ_ONLY, &zone->flags);
-
-	if (dmz_is_seq(zone))
-		zone->wp_block = dmz_sect2blk(blkz.wp - blkz.start);
-	else
-		zone->wp_block = 0;
-
 	return 0;
 }
 
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index bc143c1b2333..e8f9661a10a1 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -440,14 +440,48 @@ static int dm_blk_getgeo(struct block_device *bdev, struct hd_geometry *geo)
 	return dm_get_geometry(md, geo);
 }
 
+#ifdef CONFIG_BLK_DEV_ZONED
+int dm_report_zones_cb(struct blk_zone *zone, unsigned int idx, void *data)
+{
+	struct dm_report_zones_args *args = data;
+	sector_t sector_diff = args->tgt->begin - args->start;
+
+	/*
+	 * Ignore zones beyond the target range.
+	 */
+	if (zone->start >= args->start + args->tgt->len)
+		return 0;
+
+	/*
+	 * Remap the start sector and write pointer position of the zone
+	 * to match its position in the target range.
+	 */
+	zone->start += sector_diff;
+	if (zone->type != BLK_ZONE_TYPE_CONVENTIONAL) {
+		if (zone->cond == BLK_ZONE_COND_FULL)
+			zone->wp = zone->start + zone->len;
+		else if (zone->cond == BLK_ZONE_COND_EMPTY)
+			zone->wp = zone->start;
+		else
+			zone->wp += sector_diff;
+	}
+
+	args->next_sector = zone->start + zone->len;
+	return args->orig_cb(zone, args->zone_idx++, args->orig_data);
+}
+EXPORT_SYMBOL_GPL(dm_report_zones_cb);
+
 static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
-			       struct blk_zone *zones, unsigned int *nr_zones)
+		unsigned int nr_zones, report_zones_cb cb, void *data)
 {
-#ifdef CONFIG_BLK_DEV_ZONED
 	struct mapped_device *md = disk->private_data;
-	struct dm_target *tgt;
 	struct dm_table *map;
 	int srcu_idx, ret;
+	struct dm_report_zones_args args = {
+		.next_sector = sector,
+		.orig_data = data,
+		.orig_cb = cb,
+	};
 
 	if (dm_suspended_md(md))
 		return -EAGAIN;
@@ -456,38 +490,30 @@ static int dm_blk_report_zones(struct gendisk *disk, sector_t sector,
 	if (!map)
 		return -EIO;
 
-	tgt = dm_table_find_target(map, sector);
-	if (!tgt) {
-		ret = -EIO;
-		goto out;
-	}
+	do {
+		struct dm_target *tgt;
 
-	/*
-	 * If we are executing this, we already know that the block device
-	 * is a zoned device and so each target should have support for that
-	 * type of drive. A missing report_zones method means that the target
-	 * driver has a problem.
-	 */
-	if (WARN_ON(!tgt->type->report_zones)) {
-		ret = -EIO;
-		goto out;
-	}
+		tgt = dm_table_find_target(map, args.next_sector);
+		if (WARN_ON_ONCE(!tgt->type->report_zones)) {
+			ret = -EIO;
+			goto out;
+		}
 
-	/*
-	 * blkdev_report_zones() will loop and call this again to cover all the
-	 * zones of the target, eventually moving on to the next target.
-	 * So there is no need to loop here trying to fill the entire array
-	 * of zones.
-	 */
-	ret = tgt->type->report_zones(tgt, sector, zones, nr_zones);
+		args.tgt = tgt;
+		ret = tgt->type->report_zones(tgt, &args, nr_zones);
+		if (ret < 0)
+			goto out;
+	} while (args.zone_idx < nr_zones &&
+		 args.next_sector < get_capacity(disk));
 
+	ret = args.zone_idx;
 out:
 	dm_put_live_table(md, srcu_idx);
 	return ret;
-#else
-	return -ENOTSUPP;
-#endif
 }
+#else
+#define dm_blk_report_zones		NULL
+#endif /* CONFIG_BLK_DEV_ZONED */
 
 static int dm_prepare_ioctl(struct mapped_device *md, int *srcu_idx,
 			    struct block_device **bdev)
@@ -1213,54 +1239,6 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors)
 }
 EXPORT_SYMBOL_GPL(dm_accept_partial_bio);
 
-/*
- * The zone descriptors obtained with a zone report indicate
- * zone positions within the underlying device of the target. The zone
- * descriptors must be remapped to match their position within the dm device.
- * The caller target should obtain the zones information using
- * blkdev_report_zones() to ensure that remapping for partition offset is
- * already handled.
- */
-void dm_remap_zone_report(struct dm_target *ti, sector_t start,
-			  struct blk_zone *zones, unsigned int *nr_zones)
-{
-#ifdef CONFIG_BLK_DEV_ZONED
-	struct blk_zone *zone;
-	unsigned int nrz = *nr_zones;
-	int i;
-
-	/*
-	 * Remap the start sector and write pointer position of the zones in
-	 * the array. Since we may have obtained from the target underlying
-	 * device more zones that the target size, also adjust the number
-	 * of zones.
-	 */
-	for (i = 0; i < nrz; i++) {
-		zone = zones + i;
-		if (zone->start >= start + ti->len) {
-			memset(zone, 0, sizeof(struct blk_zone) * (nrz - i));
-			break;
-		}
-
-		zone->start = zone->start + ti->begin - start;
-		if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
-			continue;
-
-		if (zone->cond == BLK_ZONE_COND_FULL)
-			zone->wp = zone->start + zone->len;
-		else if (zone->cond == BLK_ZONE_COND_EMPTY)
-			zone->wp = zone->start;
-		else
-			zone->wp = zone->wp + ti->begin - start;
-	}
-
-	*nr_zones = i;
-#else /* !CONFIG_BLK_DEV_ZONED */
-	*nr_zones = 0;
-#endif
-}
-EXPORT_SYMBOL_GPL(dm_remap_zone_report);
-
 static blk_qc_t __map_bio(struct dm_target_io *tio)
 {
 	int r;
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index bf2102a749bc..42fd3f00e4a5 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -213,8 +213,8 @@ blk_status_t sd_zbc_setup_zone_mgmt_cmnd(struct scsi_cmnd *cmd,
 					 unsigned char op, bool all);
 extern void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
 			    struct scsi_sense_hdr *sshdr);
-extern int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
-			       struct blk_zone *zones, unsigned int *nr_zones);
+int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
+		unsigned int nr_zones, report_zones_cb cb, void *data);
 
 #else /* CONFIG_BLK_DEV_ZONED */
 
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 39f10ec0dfcf..0e5ede48f045 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -19,34 +19,27 @@
 
 #include "sd.h"
 
-/**
- * sd_zbc_parse_report - Convert a zone descriptor to a struct blk_zone,
- * @sdkp: The disk the report originated from
- * @buf: Address of the report zone descriptor
- * @zone: the destination zone structure
- *
- * All LBA sized values are converted to 512B sectors unit.
- */
-static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
-				struct blk_zone *zone)
+static int sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
+			       unsigned int idx, report_zones_cb cb, void *data)
 {
 	struct scsi_device *sdp = sdkp->device;
+	struct blk_zone zone = { 0 };
 
-	memset(zone, 0, sizeof(struct blk_zone));
-
-	zone->type = buf[0] & 0x0f;
-	zone->cond = (buf[1] >> 4) & 0xf;
+	zone.type = buf[0] & 0x0f;
+	zone.cond = (buf[1] >> 4) & 0xf;
 	if (buf[1] & 0x01)
-		zone->reset = 1;
+		zone.reset = 1;
 	if (buf[1] & 0x02)
-		zone->non_seq = 1;
-
-	zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
-	zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
-	zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
-	if (zone->type != ZBC_ZONE_TYPE_CONV &&
-	    zone->cond == ZBC_ZONE_COND_FULL)
-		zone->wp = zone->start + zone->len;
+		zone.non_seq = 1;
+
+	zone.len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
+	zone.start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
+	zone.wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
+	if (zone.type != ZBC_ZONE_TYPE_CONV &&
+	    zone.cond == ZBC_ZONE_COND_FULL)
+		zone.wp = zone.start + zone.len;
+
+	return cb(&zone, idx, data);
 }
 
 /**
@@ -104,11 +97,6 @@ static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
 	return 0;
 }
 
-/*
- * Maximum number of zones to get with one report zones command.
- */
-#define SD_ZBC_REPORT_MAX_ZONES		8192U
-
 /**
  * Allocate a buffer for report zones reply.
  * @sdkp: The target disk
@@ -138,75 +126,83 @@ static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
 	 * sure that the allocated buffer can always be mapped by limiting the
 	 * number of pages allocated to the HBA max segments limit.
 	 */
-	nr_zones = min(nr_zones, SD_ZBC_REPORT_MAX_ZONES);
-	bufsize = roundup((nr_zones + 1) * 64, 512);
+	nr_zones = min(nr_zones, sdkp->nr_zones);
+	bufsize = roundup((nr_zones + 1) * 64, SECTOR_SIZE);
 	bufsize = min_t(size_t, bufsize,
 			queue_max_hw_sectors(q) << SECTOR_SHIFT);
 	bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
 
-	buf = vzalloc(bufsize);
-	if (buf)
-		*buflen = bufsize;
+	while (bufsize >= SECTOR_SIZE) {
+		buf = __vmalloc(bufsize,
+				GFP_KERNEL | __GFP_ZERO | __GFP_NORETRY,
+				PAGE_KERNEL);
+		if (buf) {
+			*buflen = bufsize;
+			return buf;
+		}
+		bufsize >>= 1;
+	}
 
-	return buf;
+	return NULL;
 }
 
 /**
- * sd_zbc_report_zones - Disk report zones operation.
- * @disk: The target disk
- * @sector: Start 512B sector of the report
- * @zones: Array of zone descriptors
- * @nr_zones: Number of descriptors in the array
- *
- * Execute a report zones command on the target disk.
+ * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
+ * @sdkp: The target disk
  */
+static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
+{
+	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
+}
+
 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
-			struct blk_zone *zones, unsigned int *nr_zones)
+			unsigned int nr_zones, report_zones_cb cb, void *data)
 {
 	struct scsi_disk *sdkp = scsi_disk(disk);
-	unsigned int i, nrz = *nr_zones;
+	unsigned int nr, i;
 	unsigned char *buf;
-	size_t buflen = 0, offset = 0;
-	int ret = 0;
+	size_t offset, buflen = 0;
+	int zone_idx = 0;
+	int ret;
 
 	if (!sd_is_zoned(sdkp))
 		/* Not a zoned device */
 		return -EOPNOTSUPP;
 
-	buf = sd_zbc_alloc_report_buffer(sdkp, nrz, &buflen);
+	buf = sd_zbc_alloc_report_buffer(sdkp, nr_zones, &buflen);
 	if (!buf)
 		return -ENOMEM;
 
-	ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
-			sectors_to_logical(sdkp->device, sector), true);
-	if (ret)
-		goto out;
+	while (zone_idx < nr_zones && sector < get_capacity(disk)) {
+		ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
+				sectors_to_logical(sdkp->device, sector), true);
+		if (ret)
+			goto out;
+
+		offset = 0;
+		nr = min(nr_zones, get_unaligned_be32(&buf[0]) / 64);
+		if (!nr)
+			break;
+
+		for (i = 0; i < nr && zone_idx < nr_zones; i++) {
+			offset += 64;
+			ret = sd_zbc_parse_report(sdkp, buf + offset, zone_idx,
+						  cb, data);
+			if (ret)
+				goto out;
+			zone_idx++;
+		}
 
-	nrz = min(nrz, get_unaligned_be32(&buf[0]) / 64);
-	for (i = 0; i < nrz; i++) {
-		offset += 64;
-		sd_zbc_parse_report(sdkp, buf + offset, zones);
-		zones++;
+		sector += sd_zbc_zone_sectors(sdkp) * i;
 	}
 
-	*nr_zones = nrz;
-
+	ret = zone_idx;
 out:
 	kvfree(buf);
-
 	return ret;
 }
 
 /**
- * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
- * @sdkp: The target disk
- */
-static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
-{
-	return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
-}
-
-/**
  * sd_zbc_setup_zone_mgmt_cmnd - Prepare a zone ZBC_OUT command. The operations
  *			can be RESET WRITE POINTER, OPEN, CLOSE or FINISH.
  * @cmd: the command to setup
@@ -339,32 +335,18 @@ static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
  * Returns the zone size in number of blocks upon success or an error code
  * upon failure.
  */
-static int sd_zbc_check_zones(struct scsi_disk *sdkp, u32 *zblocks)
+static int sd_zbc_check_zones(struct scsi_disk *sdkp, unsigned char *buf,
+			      u32 *zblocks)
 {
-	size_t bufsize, buflen;
-	unsigned int noio_flag;
 	u64 zone_blocks = 0;
-	sector_t max_lba, block = 0;
-	unsigned char *buf;
+	sector_t max_lba;
 	unsigned char *rec;
 	int ret;
-	u8 same;
 
-	/* Do all memory allocations as if GFP_NOIO was specified */
-	noio_flag = memalloc_noio_save();
-
-	/* Get a buffer */
-	buf = sd_zbc_alloc_report_buffer(sdkp, SD_ZBC_REPORT_MAX_ZONES,
-					 &bufsize);
-	if (!buf) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	/* Do a report zone to get max_lba and the same field */
-	ret = sd_zbc_do_report_zones(sdkp, buf, bufsize, 0, false);
+	/* Do a report zone to get max_lba and the size of the first zone */
+	ret = sd_zbc_do_report_zones(sdkp, buf, SD_BUF_SIZE, 0, false);
 	if (ret)
-		goto out_free;
+		return ret;
 
 	if (sdkp->rc_basis == 0) {
 		/* The max_lba field is the capacity of this device */
@@ -379,82 +361,27 @@ static int sd_zbc_check_zones(struct scsi_disk *sdkp, u32 *zblocks)
 		}
 	}
 
-	/*
-	 * Check same field: for any value other than 0, we know that all zones
-	 * have the same size.
-	 */
-	same = buf[4] & 0x0f;
-	if (same > 0) {
-		rec = &buf[64];
-		zone_blocks = get_unaligned_be64(&rec[8]);
-		goto out;
-	}
-
-	/*
-	 * Check the size of all zones: all zones must be of
-	 * equal size, except the last zone which can be smaller
-	 * than other zones.
-	 */
-	do {
-
-		/* Parse REPORT ZONES header */
-		buflen = min_t(size_t, get_unaligned_be32(&buf[0]) + 64,
-			       bufsize);
-		rec = buf + 64;
-
-		/* Parse zone descriptors */
-		while (rec < buf + buflen) {
-			u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
-
-			if (zone_blocks == 0) {
-				zone_blocks = this_zone_blocks;
-			} else if (this_zone_blocks != zone_blocks &&
-				   (block + this_zone_blocks < sdkp->capacity
-				    || this_zone_blocks > zone_blocks)) {
-				zone_blocks = 0;
-				goto out;
-			}
-			block += this_zone_blocks;
-			rec += 64;
-		}
-
-		if (block < sdkp->capacity) {
-			ret = sd_zbc_do_report_zones(sdkp, buf, bufsize, block,
-						     true);
-			if (ret)
-				goto out_free;
-		}
-
-	} while (block < sdkp->capacity);
-
-out:
-	if (!zone_blocks) {
-		if (sdkp->first_scan)
-			sd_printk(KERN_NOTICE, sdkp,
-				  "Devices with non constant zone "
-				  "size are not supported\n");
-		ret = -ENODEV;
-	} else if (!is_power_of_2(zone_blocks)) {
+	/* Parse REPORT ZONES header */
+	rec = buf + 64;
+	zone_blocks = get_unaligned_be64(&rec[8]);
+	if (!zone_blocks || !is_power_of_2(zone_blocks)) {
 		if (sdkp->first_scan)
 			sd_printk(KERN_NOTICE, sdkp,
 				  "Devices with non power of 2 zone "
 				  "size are not supported\n");
-		ret = -ENODEV;
-	} else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
+		return -ENODEV;
+	}
+
+	if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
 		if (sdkp->first_scan)
 			sd_printk(KERN_NOTICE, sdkp,
 				  "Zone size too large\n");
-		ret = -EFBIG;
-	} else {
-		*zblocks = zone_blocks;
-		ret = 0;
+		return -EFBIG;
 	}
 
-out_free:
-	memalloc_noio_restore(noio_flag);
-	kvfree(buf);
+	*zblocks = zone_blocks;
 
-	return ret;
+	return 0;
 }
 
 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
@@ -480,7 +407,7 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 	 * Check zone size: only devices with a constant zone size (except
 	 * an eventual last runt zone) that is a power of 2 are supported.
 	 */
-	ret = sd_zbc_check_zones(sdkp, &zone_blocks);
+	ret = sd_zbc_check_zones(sdkp, buf, &zone_blocks);
 	if (ret != 0)
 		goto err;