block: remove support for the host aware zone model

When zones were first added the SCSI and ATA specs, two different
models were supported (in addition to the drive managed one that
is invisible to the host):

 - host managed where non-conventional zones there is strict requirement
   to write at the write pointer, or else an error is returned
 - host aware where a write point is maintained if writes always happen
   at it, otherwise it is left in an under-defined state and the
   sequential write preferred zones behave like conventional zones
   (probably very badly performing ones, though)

Not surprisingly this lukewarm model didn't prove to be very useful and
was finally removed from the ZBC and SBC specs (NVMe never implemented
it).  Due to to the easily disappearing write pointer host software
could never rely on the write pointer to actually be useful for say
recovery.

Fortunately only a few HDD prototypes shipped using this model which
never made it to mass production.  Drop the support before it is too
late.  Note that any such host aware prototype HDD can still be used
with Linux as we'll now treat it as a conventional HDD.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20231217165359.604246-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

11 files changed, 64 insertions, 90 deletions

diff --git a/drivers/block/null_blk/zoned.c b/drivers/block/null_blk/zoned.c
index 55c5b48bc276..369eb1e78bb5 100644
--- a/drivers/block/null_blk/zoned.c
+++ b/drivers/block/null_blk/zoned.c
@@ -159,7 +159,7 @@ int null_register_zoned_dev(struct nullb *nullb)
 	struct nullb_device *dev = nullb->dev;
 	struct request_queue *q = nullb->q;
 
-	disk_set_zoned(nullb->disk, BLK_ZONED_HM);
+	disk_set_zoned(nullb->disk, true);
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
 	blk_queue_required_elevator_features(q, ELEVATOR_F_ZBD_SEQ_WRITE);
 	blk_queue_chunk_sectors(q, dev->zone_size_sects);
diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index 83600b45e12a..24fb95f19d52 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -250,7 +250,7 @@ static int ublk_dev_param_zoned_apply(struct ublk_device *ub)
 {
 	const struct ublk_param_zoned *p = &ub->params.zoned;
 
-	disk_set_zoned(ub->ub_disk, BLK_ZONED_HM);
+	disk_set_zoned(ub->ub_disk, true);
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, ub->ub_disk->queue);
 	blk_queue_required_elevator_features(ub->ub_disk->queue,
 					     ELEVATOR_F_ZBD_SEQ_WRITE);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index a28f1687066b..19a4f20bd1c2 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -730,7 +730,7 @@ static int virtblk_probe_zoned_device(struct virtio_device *vdev,
 
 	dev_dbg(&vdev->dev, "probing host-managed zoned device\n");
 
-	disk_set_zoned(vblk->disk, BLK_ZONED_HM);
+	disk_set_zoned(vblk->disk, true);
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
 
 	virtio_cread(vdev, struct virtio_blk_config,
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index d01807c50f20..36bcfdccae04 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -807,7 +807,7 @@ void dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from,
 	 */
 	if (!(job->flags & BIT(DM_KCOPYD_WRITE_SEQ))) {
 		for (i = 0; i < job->num_dests; i++) {
-			if (bdev_zoned_model(dests[i].bdev) == BLK_ZONED_HM) {
+			if (bdev_is_zoned(dests[i].bdev)) {
 				job->flags |= BIT(DM_KCOPYD_WRITE_SEQ);
 				break;
 			}
diff --git a/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 198d38b53322..260b5b8f2b0d 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -1579,21 +1579,18 @@ bool dm_table_has_no_data_devices(struct dm_table *t)
 	return true;
 }
 
-static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
-				  sector_t start, sector_t len, void *data)
+static int device_not_zoned(struct dm_target *ti, struct dm_dev *dev,
+			    sector_t start, sector_t len, void *data)
 {
-	struct request_queue *q = bdev_get_queue(dev->bdev);
-	enum blk_zoned_model *zoned_model = data;
+	bool *zoned = data;
 
-	return blk_queue_zoned_model(q) != *zoned_model;
+	return bdev_is_zoned(dev->bdev) != *zoned;
 }
 
 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
 				 sector_t start, sector_t len, void *data)
 {
-	struct request_queue *q = bdev_get_queue(dev->bdev);
-
-	return blk_queue_zoned_model(q) != BLK_ZONED_NONE;
+	return bdev_is_zoned(dev->bdev);
 }
 
 /*
@@ -1603,8 +1600,7 @@ static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
  * zoned model with all zoned devices having the same zone size.
  */
-static bool dm_table_supports_zoned_model(struct dm_table *t,
-					  enum blk_zoned_model zoned_model)
+static bool dm_table_supports_zoned(struct dm_table *t, bool zoned)
 {
 	for (unsigned int i = 0; i < t->num_targets; i++) {
 		struct dm_target *ti = dm_table_get_target(t, i);
@@ -1623,11 +1619,11 @@ static bool dm_table_supports_zoned_model(struct dm_table *t,
 
 		if (dm_target_supports_zoned_hm(ti->type)) {
 			if (!ti->type->iterate_devices ||
-			    ti->type->iterate_devices(ti, device_not_zoned_model,
-						      &zoned_model))
+			    ti->type->iterate_devices(ti, device_not_zoned,
+						      &zoned))
 				return false;
 		} else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
-			if (zoned_model == BLK_ZONED_HM)
+			if (zoned)
 				return false;
 		}
 	}
@@ -1650,14 +1646,13 @@ static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *
  * zone sectors, if the destination device is a zoned block device, it shall
  * have the specified zone_sectors.
  */
-static int validate_hardware_zoned_model(struct dm_table *t,
-					 enum blk_zoned_model zoned_model,
-					 unsigned int zone_sectors)
+static int validate_hardware_zoned(struct dm_table *t, bool zoned,
+				   unsigned int zone_sectors)
 {
-	if (zoned_model == BLK_ZONED_NONE)
+	if (!zoned)
 		return 0;
 
-	if (!dm_table_supports_zoned_model(t, zoned_model)) {
+	if (!dm_table_supports_zoned(t, zoned)) {
 		DMERR("%s: zoned model is not consistent across all devices",
 		      dm_device_name(t->md));
 		return -EINVAL;
@@ -1683,8 +1678,8 @@ int dm_calculate_queue_limits(struct dm_table *t,
 			      struct queue_limits *limits)
 {
 	struct queue_limits ti_limits;
-	enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
 	unsigned int zone_sectors = 0;
+	bool zoned = false;
 
 	blk_set_stacking_limits(limits);
 
@@ -1706,12 +1701,12 @@ int dm_calculate_queue_limits(struct dm_table *t,
 		ti->type->iterate_devices(ti, dm_set_device_limits,
 					  &ti_limits);
 
-		if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
+		if (!zoned && ti_limits.zoned) {
 			/*
 			 * After stacking all limits, validate all devices
 			 * in table support this zoned model and zone sectors.
 			 */
-			zoned_model = ti_limits.zoned;
+			zoned = ti_limits.zoned;
 			zone_sectors = ti_limits.chunk_sectors;
 		}
 
@@ -1744,18 +1739,18 @@ combine_limits:
 	 * Verify that the zoned model and zone sectors, as determined before
 	 * any .io_hints override, are the same across all devices in the table.
 	 * - this is especially relevant if .io_hints is emulating a disk-managed
-	 *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
+	 *   zoned model on host-managed zoned block devices.
 	 * BUT...
 	 */
-	if (limits->zoned != BLK_ZONED_NONE) {
+	if (limits->zoned) {
 		/*
 		 * ...IF the above limits stacking determined a zoned model
 		 * validate that all of the table's devices conform to it.
 		 */
-		zoned_model = limits->zoned;
+		zoned = limits->zoned;
 		zone_sectors = limits->chunk_sectors;
 	}
-	if (validate_hardware_zoned_model(t, zoned_model, zone_sectors))
+	if (validate_hardware_zoned(t, zoned, zone_sectors))
 		return -EINVAL;
 
 	return validate_hardware_logical_block_alignment(t, limits);
diff --git a/drivers/md/dm-zoned-metadata.c b/drivers/md/dm-zoned-metadata.c
index 60a4dc01ea18..fdfe30f7b697 100644
--- a/drivers/md/dm-zoned-metadata.c
+++ b/drivers/md/dm-zoned-metadata.c
@@ -2836,12 +2836,11 @@ static void dmz_print_dev(struct dmz_metadata *zmd, int num)
 {
 	struct dmz_dev *dev = &zmd->dev[num];
 
-	if (bdev_zoned_model(dev->bdev) == BLK_ZONED_NONE)
+	if (!bdev_is_zoned(dev->bdev))
 		dmz_dev_info(dev, "Regular block device");
 	else
-		dmz_dev_info(dev, "Host-%s zoned block device",
-			     bdev_zoned_model(dev->bdev) == BLK_ZONED_HA ?
-			     "aware" : "managed");
+		dmz_dev_info(dev, "Host-managed zoned block device");
+
 	if (zmd->sb_version > 1) {
 		sector_t sector_offset =
 			dev->zone_offset << zmd->zone_nr_sectors_shift;
diff --git a/drivers/md/dm-zoned-target.c b/drivers/md/dm-zoned-target.c
index b487f7acc860..621794a9edd6 100644
--- a/drivers/md/dm-zoned-target.c
+++ b/drivers/md/dm-zoned-target.c
@@ -702,7 +702,7 @@ static int dmz_get_zoned_device(struct dm_target *ti, char *path,
 	}
 
 	bdev = ddev->bdev;
-	if (bdev_zoned_model(bdev) == BLK_ZONED_NONE) {
+	if (!bdev_is_zoned(bdev)) {
 		if (nr_devs == 1) {
 			ti->error = "Invalid regular device";
 			goto err;
@@ -1010,7 +1010,7 @@ static void dmz_io_hints(struct dm_target *ti, struct queue_limits *limits)
 	limits->max_sectors = chunk_sectors;
 
 	/* We are exposing a drive-managed zoned block device */
-	limits->zoned = BLK_ZONED_NONE;
+	limits->zoned = false;
 }
 
 /*
diff --git a/drivers/nvme/host/zns.c b/drivers/nvme/host/zns.c
index ec8557810c21..6d4c440e97e2 100644
--- a/drivers/nvme/host/zns.c
+++ b/drivers/nvme/host/zns.c
@@ -108,7 +108,7 @@ int nvme_update_zone_info(struct nvme_ns *ns, unsigned lbaf)
 		goto free_data;
 	}
 
-	disk_set_zoned(ns->disk, BLK_ZONED_HM);
+	disk_set_zoned(ns->disk, true);
 	blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, q);
 	disk_set_max_open_zones(ns->disk, le32_to_cpu(id->mor) + 1);
 	disk_set_max_active_zones(ns->disk, le32_to_cpu(id->mar) + 1);
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 6d8218a44122..d03d66f11493 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -339,7 +339,7 @@ struct sdebug_dev_info {
 	bool used;
 
 	/* For ZBC devices */
-	enum blk_zoned_model zmodel;
+	bool zoned;
 	unsigned int zcap;
 	unsigned int zsize;
 	unsigned int zsize_shift;
@@ -844,8 +844,11 @@ static bool write_since_sync;
 static bool sdebug_statistics = DEF_STATISTICS;
 static bool sdebug_wp;
 static bool sdebug_allow_restart;
-/* Following enum: 0: no zbc, def; 1: host aware; 2: host managed */
-static enum blk_zoned_model sdeb_zbc_model = BLK_ZONED_NONE;
+static enum {
+	BLK_ZONED_NONE	= 0,
+	BLK_ZONED_HA	= 1,
+	BLK_ZONED_HM	= 2,
+} sdeb_zbc_model = BLK_ZONED_NONE;
 static char *sdeb_zbc_model_s;
 
 enum sam_lun_addr_method {SAM_LUN_AM_PERIPHERAL = 0x0,
@@ -1815,8 +1818,6 @@ static int inquiry_vpd_b1(struct sdebug_dev_info *devip, unsigned char *arr)
 	arr[1] = 1;	/* non rotating medium (e.g. solid state) */
 	arr[2] = 0;
 	arr[3] = 5;	/* less than 1.8" */
-	if (devip->zmodel == BLK_ZONED_HA)
-		arr[4] = 1 << 4;	/* zoned field = 01b */
 
 	return 0x3c;
 }
@@ -1883,7 +1884,7 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 	if (! arr)
 		return DID_REQUEUE << 16;
 	is_disk = (sdebug_ptype == TYPE_DISK);
-	is_zbc = (devip->zmodel != BLK_ZONED_NONE);
+	is_zbc = devip->zoned;
 	is_disk_zbc = (is_disk || is_zbc);
 	have_wlun = scsi_is_wlun(scp->device->lun);
 	if (have_wlun)
@@ -2195,7 +2196,7 @@ static int resp_readcap16(struct scsi_cmnd *scp,
 	 * Since the scsi_debug READ CAPACITY implementation always reports the
 	 * total disk capacity, set RC BASIS = 1 for host-managed ZBC devices.
 	 */
-	if (devip->zmodel == BLK_ZONED_HM)
+	if (devip->zoned)
 		arr[12] |= 1 << 4;
 
 	arr[15] = sdebug_lowest_aligned & 0xff;
@@ -2648,7 +2649,7 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 	msense_6 = (MODE_SENSE == cmd[0]);
 	llbaa = msense_6 ? false : !!(cmd[1] & 0x10);
 	is_disk = (sdebug_ptype == TYPE_DISK);
-	is_zbc = (devip->zmodel != BLK_ZONED_NONE);
+	is_zbc = devip->zoned;
 	if ((is_disk || is_zbc) && !dbd)
 		bd_len = llbaa ? 16 : 8;
 	else
@@ -3194,8 +3195,6 @@ static int check_zbc_access_params(struct scsi_cmnd *scp,
 	struct sdeb_zone_state *zsp_end = zbc_zone(devip, lba + num - 1);
 
 	if (!write) {
-		if (devip->zmodel == BLK_ZONED_HA)
-			return 0;
 		/* For host-managed, reads cannot cross zone types boundaries */
 		if (zsp->z_type != zsp_end->z_type) {
 			mk_sense_buffer(scp, ILLEGAL_REQUEST,
@@ -5322,7 +5321,7 @@ static int sdebug_device_create_zones(struct sdebug_dev_info *devip)
 	if (devip->zcap < devip->zsize)
 		devip->nr_zones += devip->nr_seq_zones;
 
-	if (devip->zmodel == BLK_ZONED_HM) {
+	if (devip->zoned) {
 		/* zbc_max_open_zones can be 0, meaning "not reported" */
 		if (sdeb_zbc_max_open >= devip->nr_zones - 1)
 			devip->max_open = (devip->nr_zones - 1) / 2;
@@ -5347,7 +5346,7 @@ static int sdebug_device_create_zones(struct sdebug_dev_info *devip)
 			zsp->z_size =
 				min_t(u64, devip->zsize, capacity - zstart);
 		} else if ((zstart & (devip->zsize - 1)) == 0) {
-			if (devip->zmodel == BLK_ZONED_HM)
+			if (devip->zoned)
 				zsp->z_type = ZBC_ZTYPE_SWR;
 			else
 				zsp->z_type = ZBC_ZTYPE_SWP;
@@ -5390,13 +5389,13 @@ static struct sdebug_dev_info *sdebug_device_create(
 		}
 		devip->sdbg_host = sdbg_host;
 		if (sdeb_zbc_in_use) {
-			devip->zmodel = sdeb_zbc_model;
+			devip->zoned = sdeb_zbc_model == BLK_ZONED_HM;
 			if (sdebug_device_create_zones(devip)) {
 				kfree(devip);
 				return NULL;
 			}
 		} else {
-			devip->zmodel = BLK_ZONED_NONE;
+			devip->zoned = false;
 		}
 		devip->create_ts = ktime_get_boottime();
 		atomic_set(&devip->stopped, (sdeb_tur_ms_to_ready > 0 ? 2 : 0));
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index fa00dd503cbf..19a19eb277f5 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3117,7 +3117,6 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
 	struct request_queue *q = sdkp->disk->queue;
 	struct scsi_vpd *vpd;
 	u16 rot;
-	u8 zoned;
 
 	rcu_read_lock();
 	vpd = rcu_dereference(sdkp->device->vpd_pgb1);
@@ -3128,7 +3127,7 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
 	}
 
 	rot = get_unaligned_be16(&vpd->data[4]);
-	zoned = (vpd->data[8] >> 4) & 3;
+	sdkp->zoned = (vpd->data[8] >> 4) & 3;
 	rcu_read_unlock();
 
 	if (rot == 1) {
@@ -3138,37 +3137,33 @@ static void sd_read_block_characteristics(struct scsi_disk *sdkp)
 
 	if (sdkp->device->type == TYPE_ZBC) {
 		/*
-		 * Host-managed: Per ZBC and ZAC specifications, writes in
-		 * sequential write required zones of host-managed devices must
-		 * be aligned to the device physical block size.
+		 * Host-managed.
+		 */
+		disk_set_zoned(sdkp->disk, true);
+
+		/*
+		 * Per ZBC and ZAC specifications, writes in sequential write
+		 * required zones of host-managed devices must be aligned to
+		 * the device physical block size.
 		 */
-		disk_set_zoned(sdkp->disk, BLK_ZONED_HM);
 		blk_queue_zone_write_granularity(q, sdkp->physical_block_size);
 	} else {
-		sdkp->zoned = zoned;
-		if (sdkp->zoned == 1) {
-			/* Host-aware */
-			disk_set_zoned(sdkp->disk, BLK_ZONED_HA);
-		} else {
-			/* Regular disk or drive managed disk */
-			disk_set_zoned(sdkp->disk, BLK_ZONED_NONE);
-		}
+		/*
+		 * Anything else.  This includes host-aware device that we treat
+		 * as conventional.
+		 */
+		disk_set_zoned(sdkp->disk, false);
 	}
 
 	if (!sdkp->first_scan)
 		return;
 
-	if (blk_queue_is_zoned(q)) {
-		sd_printk(KERN_NOTICE, sdkp, "Host-%s zoned block device\n",
-		      q->limits.zoned == BLK_ZONED_HM ? "managed" : "aware");
-	} else {
-		if (sdkp->zoned == 1)
-			sd_printk(KERN_NOTICE, sdkp,
-				  "Host-aware SMR disk used as regular disk\n");
-		else if (sdkp->zoned == 2)
-			sd_printk(KERN_NOTICE, sdkp,
-				  "Drive-managed SMR disk\n");
-	}
+	if (blk_queue_is_zoned(q))
+		sd_printk(KERN_NOTICE, sdkp, "Host-managed zoned block device\n");
+	else if (sdkp->zoned == 1)
+		sd_printk(KERN_NOTICE, sdkp, "Host-aware SMR disk used as regular disk\n");
+	else if (sdkp->zoned == 2)
+		sd_printk(KERN_NOTICE, sdkp, "Drive-managed SMR disk\n");
 }
 
 /**
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index a25215507668..26af5ab7d7c1 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -836,10 +836,7 @@ int sd_zbc_revalidate_zones(struct scsi_disk *sdkp)
 
 	/*
 	 * For all zoned disks, initialize zone append emulation data if not
-	 * already done. This is necessary also for host-aware disks used as
-	 * regular disks due to the presence of partitions as these partitions
-	 * may be deleted and the disk zoned model changed back from
-	 * BLK_ZONED_NONE to BLK_ZONED_HA.
+	 * already done.
 	 */
 	if (sd_is_zoned(sdkp) && !sdkp->zone_wp_update_buf) {
 		ret = sd_zbc_init_disk(sdkp);
@@ -932,17 +929,6 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, u8 buf[SD_BUF_SIZE])
 	sdkp->device->use_10_for_rw = 0;
 	sdkp->device->use_16_for_sync = 1;
 
-	if (!blk_queue_is_zoned(q)) {
-		/*
-		 * This can happen for a host aware disk with partitions.
-		 * The block device zone model was already cleared by
-		 * disk_set_zoned(). Only free the scsi disk zone
-		 * information and exit early.
-		 */
-		sd_zbc_free_zone_info(sdkp);
-		return 0;
-	}
-
 	/* Check zoned block device characteristics (unconstrained reads) */
 	ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
 	if (ret)