Currently the RB-Tree zone cache is fast and flexible. It does
use a rather largish amount of ram. This model reduces the ram
required from 120 bytes per zone to 16 bytes per zone with a
moderate transformation of the blk_zone_lookup() api.

This model is predicated on the belief that most variations
on zoned media will follow a pattern of using collections of same
sized zones on a single device. Similar to the pattern of erase
blocks on flash devices being progressivly larger 16K, 64K, ...

The goal is to be able to build a descriptor which is both memory
efficient, performant, and flexible.

Signed-off-by: Shaun Tancheff <shaun.tanch...@seagate.com>
---
 block/blk-core.c       |    2 +-
 block/blk-sysfs.c      |   31 +-
 block/blk-zoned.c      |  103 +++--
 drivers/scsi/sd.c      |    5 +-
 drivers/scsi/sd.h      |    4 +-
 drivers/scsi/sd_zbc.c  | 1025 +++++++++++++++++++++++++++---------------------
 include/linux/blkdev.h |   82 +++-
 7 files changed, 716 insertions(+), 536 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 3a9caf7..3b084a8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -727,7 +727,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, 
int node_id)
        INIT_LIST_HEAD(&q->blkg_list);
 #endif
 #ifdef CONFIG_BLK_DEV_ZONED
-       q->zones = RB_ROOT;
+       q->zones = NULL;
 #endif
        INIT_DELAYED_WORK(&q->delay_work, blk_delay_work);
 
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 43f441f..ecbd434 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -232,36 +232,7 @@ static ssize_t queue_max_hw_sectors_show(struct 
request_queue *q, char *page)
 #ifdef CONFIG_BLK_DEV_ZONED
 static ssize_t queue_zoned_show(struct request_queue *q, char *page)
 {
-       struct rb_node *node;
-       struct blk_zone *zone;
-       ssize_t offset = 0, end = 0;
-       size_t size = 0, num = 0;
-       enum blk_zone_type type = BLK_ZONE_TYPE_UNKNOWN;
-
-       for (node = rb_first(&q->zones); node; node = rb_next(node)) {
-               zone = rb_entry(node, struct blk_zone, node);
-               if (zone->type != type ||
-                   zone->len != size ||
-                   end != zone->start) {
-                       if (size != 0)
-                               offset += sprintf(page + offset, "%zu\n", num);
-                       /* We can only store one page ... */
-                       if (offset + 42 > PAGE_SIZE) {
-                               offset += sprintf(page + offset, "...\n");
-                               return offset;
-                       }
-                       size = zone->len;
-                       type = zone->type;
-                       offset += sprintf(page + offset, "%zu %zu %d ",
-                                         zone->start, size, type);
-                       num = 0;
-                       end = zone->start + size;
-               } else
-                       end += zone->len;
-               num++;
-       }
-       offset += sprintf(page + offset, "%zu\n", num);
-       return offset;
+       return sprintf(page, "%u\n", q->zones ? 1 : 0);
 }
 #endif
 
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 975e863..338a1af 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -8,63 +8,84 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/blkdev.h>
-#include <linux/rbtree.h>
+#include <linux/vmalloc.h>
 
-struct blk_zone *blk_lookup_zone(struct request_queue *q, sector_t lba)
+/**
+ * blk_lookup_zone() - Lookup zones
+ * @q: Request Queue
+ * @sector: Location to lookup
+ * @start: Pointer to starting location zone (OUT)
+ * @len: Pointer to length of zone (OUT)
+ * @lock: Pointer to spinlock of zones in owning descriptor (OUT)
+ */
+struct blk_zone *blk_lookup_zone(struct request_queue *q, sector_t sector,
+                                sector_t *start, sector_t *len,
+                                spinlock_t **lock)
 {
-       struct rb_root *root = &q->zones;
-       struct rb_node *node = root->rb_node;
+       int iter;
+       struct blk_zone *bzone = NULL;
+       struct zone_wps *zi = q->zones;
+
+       *start = 0;
+       *len = 0;
+       *lock = NULL;
+
+       if (!q->zones)
+               goto out;
 
-       while (node) {
-               struct blk_zone *zone = container_of(node, struct blk_zone,
-                                                    node);
+       for (iter = 0; iter < zi->wps_count; iter++) {
+               if (sector >= zi->wps[iter]->start_lba &&
+                   sector <  zi->wps[iter]->last_lba) {
+                       struct contiguous_wps *wp = zi->wps[iter];
+                       u64 index = (sector - wp->start_lba) / wp->zone_size;
 
-               if (lba < zone->start)
-                       node = node->rb_left;
-               else if (lba >= zone->start + zone->len)
-                       node = node->rb_right;
-               else
-                       return zone;
+                       if (index >= wp->zone_count) {
+                               WARN(1, "Impossible index for zone\n");
+                               goto out;
+                       }
+
+                       bzone = &wp->zones[index];
+                       *len = wp->zone_size;
+                       *start = wp->start_lba + (index * wp->zone_size);
+                       *lock = &wp->lock;
+               }
        }
-       return NULL;
+
+out:
+       return bzone;
 }
 EXPORT_SYMBOL_GPL(blk_lookup_zone);
 
-struct blk_zone *blk_insert_zone(struct request_queue *q, struct blk_zone 
*data)
+/**
+ * free_zone_wps() - Free up memory in use by wps
+ * @zi: zone wps array(s).
+ */
+static void free_zone_wps(struct zone_wps *zi)
 {
-       struct rb_root *root = &q->zones;
-       struct rb_node **new = &(root->rb_node), *parent = NULL;
+       /* on error free the arrays */
+       if (zi && zi->wps) {
+               int ca;
 
-       /* Figure out where to put new node */
-       while (*new) {
-               struct blk_zone *this = container_of(*new, struct blk_zone,
-                                                    node);
-               parent = *new;
-               if (data->start + data->len <= this->start)
-                       new = &((*new)->rb_left);
-               else if (data->start >= this->start + this->len)
-                       new = &((*new)->rb_right);
-               else {
-                       /* Return existing zone */
-                       return this;
+               for (ca = 0; ca < zi->wps_count; ca++) {
+                       if (zi->wps[ca]) {
+                               vfree(zi->wps[ca]);
+                               zi->wps[ca] = NULL;
+                       }
                }
+               kfree(zi->wps);
        }
-       /* Add new node and rebalance tree. */
-       rb_link_node(&data->node, parent, new);
-       rb_insert_color(&data->node, root);
-
-       return NULL;
 }
-EXPORT_SYMBOL_GPL(blk_insert_zone);
 
+/**
+ * blk_drop_zones() - Free zones
+ * @q: Request Queue
+ */
 void blk_drop_zones(struct request_queue *q)
 {
-       struct rb_root *root = &q->zones;
-       struct blk_zone *zone, *next;
-
-       rbtree_postorder_for_each_entry_safe(zone, next, root, node) {
-               kfree(zone);
+       if (q->zones) {
+               free_zone_wps(q->zones);
+               kfree(q->zones);
+               q->zones = NULL;
        }
-       q->zones = RB_ROOT;
 }
 EXPORT_SYMBOL_GPL(blk_drop_zones);
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index f144df4..0f749f5 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -2549,8 +2549,9 @@ got_data:
                                      sdkp->physical_block_size);
        sdkp->device->sector_size = sector_size;
 
-       if (sd_zbc_config(sdkp, buffer, SD_BUF_SIZE))
-               sd_config_discard(sdkp, SD_ZBC_RESET_WP);
+       if (sdkp->first_scan)
+               if (sd_zbc_config(sdkp, GFP_KERNEL))
+                       sd_config_discard(sdkp, SD_ZBC_RESET_WP);
 
        {
                char cap_str_2[10], cap_str_10[10];
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index fc766db..c9c79e9 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -299,13 +299,13 @@ extern void sd_zbc_uninit_command(struct scsi_cmnd *cmd);
 extern void sd_zbc_remove(struct scsi_disk *);
 extern void sd_zbc_reset_zones(struct scsi_disk *);
 extern void sd_zbc_update_zones(struct scsi_disk *, sector_t, int, int reason);
-extern bool sd_zbc_config(struct scsi_disk *, void *, size_t);
+extern bool sd_zbc_config(struct scsi_disk *, gfp_t);
 
 extern unsigned int sd_zbc_discard_granularity(struct scsi_disk *sdkp);
 
 #else /* CONFIG_SCSI_ZBC */
 
-static inline bool sd_zbc_config(struct scsi_disk *sdkp, void *b, size_t sz)
+static inline bool sd_zbc_config(struct scsi_disk *sdkp, gfp_t gfp)
 {
        return false;
 }
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index 960af93..c087035 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -22,6 +22,7 @@
 
 #include <linux/blkdev.h>
 #include <linux/rbtree.h>
+#include <linux/vmalloc.h>
 
 #include <asm/unaligned.h>
 
@@ -51,11 +52,11 @@
        } while( 0 )
 
 struct zbc_update_work {
-       struct work_struct zone_work;
-       struct scsi_disk *sdkp;
-       sector_t        zone_sector;
-       int             zone_buflen;
-       char            zone_buf[0];
+       struct work_struct      zone_work;
+       struct scsi_disk        *sdkp;
+       sector_t                zone_sector;
+       int                     zone_buflen;
+       struct bdev_zone_report zone_buf[0];
 };
 
 /**
@@ -95,102 +96,19 @@ static inline sector_t get_start_from_desc(struct 
scsi_disk *sdkp,
        return logical_to_sectors(sdkp->device, be64_to_cpu(bzde->lba_start));
 }
 
-static
-struct blk_zone *zbc_desc_to_zone(struct scsi_disk *sdkp, unsigned char *rec)
+static void _fill_zone(struct blk_zone *zone, struct scsi_disk *sdkp,
+                      struct bdev_zone_descriptor *bzde)
 {
-       struct blk_zone *zone;
-       sector_t wp = (sector_t)-1;
-
-       zone = kzalloc(sizeof(struct blk_zone), GFP_KERNEL);
-       if (!zone)
-               return NULL;
-
-       spin_lock_init(&zone->lock);
-       zone->type = rec[0] & 0xf;
-       zone->state = (rec[1] >> 4) & 0xf;
-       zone->len = logical_to_sectors(sdkp->device,
-                                      get_unaligned_be64(&rec[8]));
-       zone->start = logical_to_sectors(sdkp->device,
-                                        get_unaligned_be64(&rec[16]));
-
-       if (blk_zone_is_smr(zone))
-               wp = logical_to_sectors(sdkp->device,
-                                       get_unaligned_be64(&rec[24]));
-       zone->wp = wp;
-       /*
-        * Fixup block zone state
-        */
-       if (zone->state == BLK_ZONE_EMPTY &&
-           zone->wp != zone->start) {
-               sd_zbc_debug(sdkp,
-                            "zone %zu state EMPTY wp %zu: adjust wp\n",
-                            zone->start, zone->wp);
-               zone->wp = zone->start;
-       }
-       if (zone->state == BLK_ZONE_FULL &&
-           zone->wp != zone->start + zone->len) {
-               sd_zbc_debug(sdkp,
-                            "zone %zu state FULL wp %zu: adjust wp\n",
-                            zone->start, zone->wp);
-               zone->wp = zone->start + zone->len;
-       }
-
-       return zone;
+       zone->type = bzde->type & 0x0f;
+       zone->state = (bzde->flags >> 4) & 0x0f;
+       zone->wp = get_wp_from_desc(sdkp, bzde);
 }
 
-static
-sector_t zbc_parse_zones(struct scsi_disk *sdkp, u64 zlen, unsigned char *buf,
-                        unsigned int buf_len)
-{
-       struct request_queue *q = sdkp->disk->queue;
-       unsigned char *rec = buf;
-       int rec_no = 0;
-       unsigned int list_length;
-       sector_t next_sector = -1;
-       u8 same;
-
-       /* Parse REPORT ZONES header */
-       list_length = get_unaligned_be32(&buf[0]);
-       same = buf[4] & 0xf;
-       rec = buf + 64;
-       list_length += 64;
-
-       if (list_length < buf_len)
-               buf_len = list_length;
-
-       while (rec < buf + buf_len) {
-               struct blk_zone *this, *old;
-               unsigned long flags;
 
-               this = zbc_desc_to_zone(sdkp, rec);
-               if (!this)
-                       break;
-
-               if (same == 0 && this->len != zlen) {
-                       next_sector = this->start + this->len;
-                       break;
-               }
-
-               next_sector = this->start + this->len;
-               old = blk_insert_zone(q, this);
-               if (old) {
-                       spin_lock_irqsave(&old->lock, flags);
-                       if (blk_zone_is_smr(old)) {
-                               old->wp = this->wp;
-                               old->state = this->state;
-                       }
-                       spin_unlock_irqrestore(&old->lock, flags);
-                       kfree(this);
-               }
-               rec += 64;
-               rec_no++;
-       }
-
-       sd_zbc_debug(sdkp,
-                    "Inserted %d zones, next sector %zu len %d\n",
-                    rec_no, next_sector, list_length);
-
-       return next_sector;
+static void fill_zone(struct contiguous_wps *cwps, int z_count,
+                     struct scsi_disk *sdkp, struct bdev_zone_descriptor *bzde)
+{
+       _fill_zone(&cwps->zones[z_count], sdkp, bzde);
 }
 
 /**
@@ -200,12 +118,10 @@ sector_t zbc_parse_zones(struct scsi_disk *sdkp, u64 
zlen, unsigned char *buf,
  * @bufflen: length of @buffer
  * @start_sector: logical sector for the zone information should be reported
  * @option: reporting option to be used
- * @partial: flag to set the 'partial' bit for report zones command
  */
-static int sd_zbc_report_zones(struct scsi_disk *sdkp, void *buffer,
-                              int bufflen, sector_t start_sector,
-                              enum zbc_zone_reporting_options option,
-                              bool partial)
+static int sd_zbc_report_zones(struct scsi_disk *sdkp,
+                              struct bdev_zone_report *buffer,
+                              int bufflen, sector_t start_sector, u8 option)
 {
        struct scsi_device *sdp = sdkp->device;
        const int timeout = sdp->request_queue->rq_timeout
@@ -225,7 +141,7 @@ static int sd_zbc_report_zones(struct scsi_disk *sdkp, void 
*buffer,
        cmd[1] = ZI_REPORT_ZONES;
        put_unaligned_be64(start_lba, &cmd[2]);
        put_unaligned_be32(bufflen, &cmd[10]);
-       cmd[14] = (partial ? ZBC_REPORT_ZONE_PARTIAL : 0) | option;
+       cmd[14] = option;
        memset(buffer, 0, bufflen);
 
        result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
@@ -248,49 +164,38 @@ static void sd_zbc_refresh_zone_work(struct work_struct 
*work)
                container_of(work, struct zbc_update_work, zone_work);
        struct scsi_disk *sdkp = zbc_work->sdkp;
        struct request_queue *q = sdkp->disk->queue;
-       unsigned char *zone_buf = zbc_work->zone_buf;
+       struct bdev_zone_report *rpt = zbc_work->zone_buf;
        unsigned int zone_buflen = zbc_work->zone_buflen;
+       struct bdev_zone_descriptor *bzde;
+       int iter;
+       int offmax;
+       sector_t z_at, z_start, z_len;
+       spinlock_t *lock;
+       struct blk_zone *zone;
        int ret;
-       u8 same;
-       u64 zlen = 0;
        sector_t last_sector;
        sector_t capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
 
-       ret = sd_zbc_report_zones(sdkp, zone_buf, zone_buflen,
+       ret = sd_zbc_report_zones(sdkp, rpt, zone_buflen,
                                  zbc_work->zone_sector,
-                                 ZBC_ZONE_REPORTING_OPTION_ALL, true);
+                                 ZBC_ZONE_REPORTING_OPTION_ALL);
        if (ret)
                goto done_free;
 
-       /* this whole path is unlikely so extra reports shouldn't be a
-        * large impact */
-       same = zone_buf[4] & 0xf;
-       if (same == 0) {
-               unsigned char *desc = &zone_buf[64];
-               unsigned int blen = zone_buflen;
-
-               /* just pull the first zone */
-               if (blen > 512)
-                       blen = 512;
-               ret = sd_zbc_report_zones(sdkp, zone_buf, blen, 0,
-                                         ZBC_ZONE_REPORTING_OPTION_ALL, true);
-               if (ret)
-                       goto done_free;
-
-               /* Read the zone length from the first zone descriptor */
-               zlen = logical_to_sectors(sdkp->device,
-                                         get_unaligned_be64(&desc[8]));
-
-               ret = sd_zbc_report_zones(sdkp, zone_buf, zone_buflen,
-                                         zbc_work->zone_sector,
-                                         ZBC_ZONE_REPORTING_OPTION_ALL, true);
-               if (ret)
-                       goto done_free;
+       offmax = max_report_entries(zone_buflen);
+       for (iter = 0; iter < offmax; iter++) {
+               bzde = &rpt->descriptors[iter];
+               z_at = get_start_from_desc(sdkp, bzde);
+               if (!z_at)
+                       break;
+               zone = blk_lookup_zone(q, z_at, &z_start, &z_len, &lock);
+               if (zone) {
+                       _fill_zone(zone, sdkp, bzde);
+                       last_sector = z_start + z_len;
+               }
        }
 
-       last_sector = zbc_parse_zones(sdkp, zlen, zone_buf, zone_buflen);
-       capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
-       if (last_sector != -1 && last_sector < capacity) {
+       if (sdkp->zone_work_q && last_sector != -1 && last_sector < capacity) {
                if (test_bit(SD_ZBC_ZONE_RESET, &sdkp->zone_flags)) {
                        sd_zbc_debug(sdkp,
                                     "zones in reset, canceling refresh\n");
@@ -333,10 +238,7 @@ void sd_zbc_update_zones(struct scsi_disk *sdkp, sector_t 
sector, int bufsize,
 {
        struct request_queue *q = sdkp->disk->queue;
        struct zbc_update_work *zbc_work;
-       struct blk_zone *zone;
-       struct rb_node *node;
-       int zone_num = 0, zone_busy = 0, num_rec;
-       sector_t next_sector = sector;
+       int num_rec;
 
        if (test_bit(SD_ZBC_ZONE_RESET, &sdkp->zone_flags)) {
                sd_zbc_debug(sdkp,
@@ -346,18 +248,23 @@ void sd_zbc_update_zones(struct scsi_disk *sdkp, sector_t 
sector, int bufsize,
 
        if (reason != SD_ZBC_INIT) {
                /* lookup sector, is zone pref? then ignore */
-               struct blk_zone *zone = blk_lookup_zone(q, sector);
-
+               sector_t z_start, z_len;
+               spinlock_t *lck;
+               struct blk_zone *zone = blk_lookup_zone(q, sector, &z_start,
+                                                       &z_len, &lck);
+               /* zone actions on conventional zones are invalid */
+               if (zone && reason == SD_ZBC_RESET_WP && blk_zone_is_cmr(zone))
+                       return;
                if (reason == SD_ZBC_RESET_WP)
                        sd_zbc_debug(sdkp, "RESET WP failed %lx\n", sector);
-
-               if (zone && blk_zone_is_seq_pref(zone))
-                       return;
        }
 
+       if (!sdkp->zone_work_q)
+               return;
+
 retry:
        zbc_work = kzalloc(sizeof(struct zbc_update_work) + bufsize,
-                          reason != SD_ZBC_INIT ? GFP_NOWAIT : GFP_KERNEL);
+                          reason != SD_ZBC_INIT ? GFP_ATOMIC : GFP_KERNEL);
        if (!zbc_work) {
                if (bufsize > 512) {
                        sd_zbc_debug(sdkp,
@@ -381,30 +288,40 @@ retry:
         * Mark zones under update as BUSY
         */
        if (reason != SD_ZBC_INIT) {
-               for (node = rb_first(&q->zones); node; node = rb_next(node)) {
-                       unsigned long flags;
-
-                       zone = rb_entry(node, struct blk_zone, node);
-                       if (num_rec == 0)
+               unsigned long flags;
+               int iter;
+               struct zone_wps *zi = q->zones;
+               struct contiguous_wps *wp = NULL;
+               u64 index = -1;
+               int zone_busy = 0;
+               int z_flgd = 0;
+
+               for (iter = 0; iter < zi->wps_count; iter++) {
+                       if (sector >= zi->wps[iter]->start_lba &&
+                           sector <  zi->wps[iter]->last_lba) {
+                               wp = zi->wps[iter];
                                break;
-                       if (zone->start != next_sector)
-                               continue;
-                       next_sector += zone->len;
-                       num_rec--;
-
-                       spin_lock_irqsave(&zone->lock, flags);
-                       if (blk_zone_is_smr(zone)) {
-                               if (zone->state == BLK_ZONE_BUSY) {
+                       }
+               }
+               if (wp) {
+                       spin_lock_irqsave(&wp->lock, flags);
+                       index = (sector - wp->start_lba) / wp->zone_size;
+                       while (index < wp->zone_count && z_flgd < num_rec) {
+                               struct blk_zone *bzone = &wp->zones[index];
+
+                               index++;
+                               z_flgd++;
+                               if (!blk_zone_is_smr(bzone))
+                                       continue;
+
+                               if (bzone->state == BLK_ZONE_BUSY)
                                        zone_busy++;
-                               } else {
-                                       zone->state = BLK_ZONE_BUSY;
-                                       zone->wp = zone->start;
-                               }
-                               zone_num++;
+                               else
+                                       bzone->state = BLK_ZONE_BUSY;
                        }
-                       spin_unlock_irqrestore(&zone->lock, flags);
+                       spin_unlock_irqrestore(&wp->lock, flags);
                }
-               if (zone_num && (zone_num == zone_busy)) {
+               if (z_flgd && (z_flgd == zone_busy)) {
                        sd_zbc_debug(sdkp,
                                     "zone update for %zu in progress\n",
                                     sector);
@@ -476,43 +393,26 @@ static void discard_or_write_same(struct scsi_cmnd *cmd, 
sector_t sector,
 int sd_zbc_setup_discard(struct scsi_cmnd *cmd)
 {
        struct request *rq = cmd->request;
-       struct scsi_device *sdp = cmd->device;
        struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
        sector_t sector = blk_rq_pos(rq);
        unsigned int nr_sectors = blk_rq_sectors(rq);
        int ret = BLKPREP_OK;
        struct blk_zone *zone;
        unsigned long flags;
-       u32 wp_offset;
        bool use_write_same = false;
+       sector_t z_start, z_len;
+       spinlock_t *lck;
 
-       zone = blk_lookup_zone(rq->q, sector);
-       if (!zone) {
-               /* Test for a runt zone before giving up */
-               if (sdp->type != TYPE_ZBC) {
-                       struct request_queue *q = rq->q;
-                       struct rb_node *node;
-
-                       node = rb_last(&q->zones);
-                       if (node)
-                               zone = rb_entry(node, struct blk_zone, node);
-                       if (zone) {
-                               spin_lock_irqsave(&zone->lock, flags);
-                               if ((zone->start + zone->len) <= sector)
-                                       goto out;
-                               spin_unlock_irqrestore(&zone->lock, flags);
-                               zone = NULL;
-                       }
-               }
+       zone = blk_lookup_zone(rq->q, sector, &z_start, &z_len, &lck);
+       if (!zone)
                return BLKPREP_KILL;
-       }
 
-       spin_lock_irqsave(&zone->lock, flags);
+       spin_lock_irqsave(lck, flags);
        if (zone->state == BLK_ZONE_UNKNOWN ||
            zone->state == BLK_ZONE_BUSY) {
                sd_zbc_debug_ratelimit(sdkp,
                                       "Discarding zone %zx state %x, 
deferring\n",
-                                      zone->start, zone->state);
+                                      z_start, zone->state);
                ret = BLKPREP_DEFER;
                goto out;
        }
@@ -520,39 +420,37 @@ int sd_zbc_setup_discard(struct scsi_cmnd *cmd)
                /* let the drive fail the command */
                sd_zbc_debug_ratelimit(sdkp,
                                       "Discarding offline zone %zx\n",
-                                      zone->start);
+                                      z_start);
                goto out;
        }
        if (blk_zone_is_cmr(zone)) {
                use_write_same = true;
                sd_zbc_debug_ratelimit(sdkp,
-                                      "Discarding CMR zone %zx\n",
-                                      zone->start);
+                                      "Discarding CMR zone %zx\n", z_start);
                goto out;
        }
-       if (zone->start != sector || zone->len < nr_sectors) {
+       if (z_start != sector || z_len < nr_sectors) {
                sd_printk(KERN_ERR, sdkp,
                          "Misaligned RESET WP %zx/%x on zone %zx/%zx\n",
-                         sector, nr_sectors, zone->start, zone->len);
+                         sector, nr_sectors, z_start, z_len);
                ret = BLKPREP_KILL;
                goto out;
        }
        /* Protect against Reset WP when more data had been written to the
         * zone than is being discarded.
         */
-       wp_offset = zone->wp - zone->start;
-       if (wp_offset > nr_sectors) {
+       if (zone->wp > nr_sectors) {
                sd_printk(KERN_ERR, sdkp,
-                         "Will Corrupt RESET WP %zx/%x/%x on zone 
%zx/%zx/%zx\n",
-                         sector, wp_offset, nr_sectors,
-                         zone->start, zone->wp, zone->len);
+                         "Will Corrupt RESET WP %zx/%zx/%x on zone 
%zx/%zx/%zx\n",
+                         sector, (sector_t)zone->wp, nr_sectors,
+                         z_start, z_start + zone->wp, z_len);
                ret = BLKPREP_KILL;
                goto out;
        }
        if (blk_zone_is_empty(zone)) {
                sd_zbc_debug_ratelimit(sdkp,
                                       "Discarding empty zone %zx [WP: %zx]\n",
-                                      zone->start, zone->wp);
+                                      z_start, (sector_t)zone->wp);
                ret = BLKPREP_DONE;
                goto out;
        }
@@ -563,8 +461,8 @@ out:
         * zone update if RESET WRITE POINTER fails.
         */
        if (ret == BLKPREP_OK && !use_write_same)
-               zone->wp = zone->start;
-       spin_unlock_irqrestore(&zone->lock, flags);
+               zone->wp = 0;
+       spin_unlock_irqrestore(lck, flags);
 
        if (ret == BLKPREP_OK)
                discard_or_write_same(cmd, sector, nr_sectors, use_write_same);
@@ -573,13 +471,14 @@ out:
 }
 
 
-static void __set_zone_state(struct blk_zone *zone, int op)
+static void __set_zone_state(struct blk_zone *zone, sector_t z_len,
+                            spinlock_t *lck, int op)
 {
        unsigned long flags;
 
-       spin_lock_irqsave(&zone->lock, flags);
-       if (blk_zone_is_cmr(zone))
-               goto out_unlock;
+       spin_lock_irqsave(lck, flags);
+       if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+               goto out;
 
        switch (op) {
        case REQ_OP_ZONE_OPEN:
@@ -587,38 +486,45 @@ static void __set_zone_state(struct blk_zone *zone, int 
op)
                break;
        case REQ_OP_ZONE_FINISH:
                zone->state = BLK_ZONE_FULL;
-               zone->wp = zone->start + zone->len;
+               zone->wp = z_len;
                break;
        case REQ_OP_ZONE_CLOSE:
                zone->state = BLK_ZONE_CLOSED;
                break;
        case REQ_OP_ZONE_RESET:
-               zone->wp = zone->start;
+               zone->wp = 0;
                break;
        default:
                WARN_ONCE(1, "%s: invalid op code: %u\n", __func__, op);
        }
-out_unlock:
-       spin_unlock_irqrestore(&zone->lock, flags);
+out:
+       spin_unlock_irqrestore(lck, flags);
 }
 
 static void update_zone_state(struct request *rq, sector_t lba, unsigned int 
op)
 {
-       struct request_queue *q = rq->q;
-       struct blk_zone *zone = NULL;
+       struct blk_zone *zone;
 
        if (lba == ~0ul) {
-               struct rb_node *node;
-
-               for (node = rb_first(&q->zones); node; node = rb_next(node)) {
-                       zone = rb_entry(node, struct blk_zone, node);
-                       __set_zone_state(zone, op);
+               struct zone_wps *zi = rq->q->zones;
+               struct contiguous_wps *wp;
+               u32 iter, entry;
+
+               for (iter = 0; iter < zi->wps_count; iter++) {
+                       wp = zi->wps[iter];
+                       for (entry = 0; entry < wp->zone_count; entry++) {
+                               zone = &wp->zones[entry];
+                               __set_zone_state(zone, wp->zone_size, &wp->lock,
+                                                op);
+                       }
                }
-               return;
        } else {
-               zone = blk_lookup_zone(q, lba);
+               sector_t z_start, z_len;
+               spinlock_t *lck;
+
+               zone = blk_lookup_zone(rq->q, lba, &z_start, &z_len, &lck);
                if (zone)
-                       __set_zone_state(zone, op);
+                       __set_zone_state(zone, z_len, lck, op);
        }
 }
 
@@ -641,6 +547,8 @@ int sd_zbc_setup_zone_action(struct scsi_cmnd *cmd)
        struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
        sector_t sector = blk_rq_pos(rq);
        struct blk_zone *zone;
+       spinlock_t *lck;
+       sector_t z_start, z_len;
        unsigned long flags;
        unsigned int nr_sectors;
        int ret = BLKPREP_DONE;
@@ -651,17 +559,17 @@ int sd_zbc_setup_zone_action(struct scsi_cmnd *cmd)
        if (is_fua || op != REQ_OP_ZONE_RESET)
                goto out;
 
-       zone = blk_lookup_zone(rq->q, sector);
+       zone = blk_lookup_zone(rq->q, sector, &z_start, &z_len, &lck);
        if (!zone || sdkp->provisioning_mode != SD_ZBC_RESET_WP)
                goto out;
 
        /* Map a Reset WP w/o FUA to a discard request */
-       spin_lock_irqsave(&zone->lock, flags);
-       sector = zone->start;
-       nr_sectors = zone->len;
+       spin_lock_irqsave(lck, flags);
+       sector = z_start;
+       nr_sectors = z_len;
        if (blk_zone_is_cmr(zone))
                use_write_same = true;
-       spin_unlock_irqrestore(&zone->lock, flags);
+       spin_unlock_irqrestore(lck, flags);
 
        rq->completion_data = NULL;
        if (use_write_same) {
@@ -712,137 +620,157 @@ static sector_t bzrpt_fill(struct request *rq,
                           struct bdev_zone_descriptor *bzd,
                           size_t sz, sector_t lba, u8 opt)
 {
-       struct request_queue *q = rq->q;
        struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+       struct scsi_device *sdp = sdkp->device;
+       struct zone_wps *zi = rq->q->zones;
+       struct contiguous_wps *wpdscr;
        struct blk_zone *zone = NULL;
-       struct rb_node *node = NULL;
        sector_t progress = lba;
        sector_t clen = ~0ul;
+       sector_t z_start, z_len, z_wp_abs;
        unsigned long flags;
        u32 max_entries = bzrpt ? max_report_entries(sz) : sz / sizeof(*bzd);
        u32 entry = 0;
+       u32 iter, idscr;
        int len_diffs = 0;
        int type_diffs = 0;
        u8 ctype;
        u8 same = 0;
 
-       zone = blk_lookup_zone(q, lba);
-       if (zone)
-               node = &zone->node;
-
-       for (entry = 0; entry < max_entries && node; node = rb_next(node)) {
-               u64 z_len, z_start, z_wp_abs;
-               u8 cond = 0;
-               u8 flgs = 0;
-
-               spin_lock_irqsave(&zone->lock, flags);
-               z_len = zone->len;
-               z_start = zone->start;
-               z_wp_abs = zone->wp;
-               progress = z_start + z_len;
-               cond = zone->state;
-               if (blk_zone_is_cmr(zone))
-                       flgs |= 0x02;
-               else if (zone->wp != zone->start)
-                       flgs |= 0x01; /* flag as RWP recommended? */
-               spin_unlock_irqrestore(&zone->lock, flags);
-
-               switch (opt & ZBC_REPORT_OPTION_MASK) {
-               case ZBC_ZONE_REPORTING_OPTION_EMPTY:
-                       if (z_wp_abs != z_start)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_IMPLICIT_OPEN:
-                       if (cond != BLK_ZONE_OPEN)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_EXPLICIT_OPEN:
-                       if (cond != BLK_ZONE_OPEN_EXPLICIT)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_CLOSED:
-                       if (cond != BLK_ZONE_CLOSED)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_FULL:
-                       if (cond != BLK_ZONE_FULL)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_READONLY:
-                       if (cond == BLK_ZONE_READONLY)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_OFFLINE:
-                       if (cond == BLK_ZONE_OFFLINE)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_NEED_RESET_WP:
-                       if (z_wp_abs == z_start)
-                               continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_NON_WP:
-                       if (cond == BLK_ZONE_NO_WP)
+       for (iter = 0; entry < max_entries && iter < zi->wps_count; iter++) {
+               wpdscr = zi->wps[iter];
+               if (lba > wpdscr->last_lba)
+                       continue;
+
+               spin_lock_irqsave(&wpdscr->lock, flags);
+               for (idscr = 0;
+                    entry < max_entries && idscr < wpdscr->zone_count;
+                    idscr++) {
+                       struct bdev_zone_descriptor *dscr;
+                       u64 zoff = idscr * wpdscr->zone_size;
+                       u8 cond, flgs = 0;
+
+                       z_len = wpdscr->zone_size;
+                       zoff = idscr * z_len;
+                       z_start = wpdscr->start_lba + zoff;
+                       if (lba >= z_start + z_len)
                                continue;
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_NON_SEQWRITE:
-                       /* this can only be reported by the HW */
-                       break;
-               case ZBC_ZONE_REPORTING_OPTION_ALL:
-               default:
-                       break;
-               }
 
-               /* if same code only applies to returned zones */
-               if (opt & ZBC_REPORT_ZONE_PARTIAL) {
-                       if (clen != ~0ul) {
-                               clen = z_len;
+                       zone = &wpdscr->zones[idscr];
+                       if (blk_zone_is_cmr(zone))
+                               z_wp_abs = z_start + wpdscr->zone_size;
+                       else
+                               z_wp_abs = z_start + zone->wp;
+
+                       switch (opt & ZBC_REPORT_OPTION_MASK) {
+                       case ZBC_ZONE_REPORTING_OPTION_EMPTY:
+                               if (z_wp_abs != z_start)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_IMPLICIT_OPEN:
+                               if (zone->state != BLK_ZONE_OPEN)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_EXPLICIT_OPEN:
+                               if (zone->state != BLK_ZONE_OPEN_EXPLICIT)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_CLOSED:
+                               if (zone->state != BLK_ZONE_CLOSED)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_FULL:
+                               if (zone->state != BLK_ZONE_FULL)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_READONLY:
+                               if (zone->state == BLK_ZONE_READONLY)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_OFFLINE:
+                               if (zone->state == BLK_ZONE_OFFLINE)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_NEED_RESET_WP:
+                               if (z_wp_abs == z_start)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_NON_WP:
+                               if (zone->state == BLK_ZONE_NO_WP)
+                                       continue;
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_NON_SEQWRITE:
+                               /* this can only be reported by the HW */
+                               break;
+                       case ZBC_ZONE_REPORTING_OPTION_ALL:
+                       default:
+                               break;
+                       }
+
+                       /* if same code only applies to returned zones */
+                       if (opt & ZBC_REPORT_ZONE_PARTIAL) {
+                               if (clen != ~0ul) {
+                                       clen = z_len;
+                                       ctype = zone->type;
+                               }
+                               if (z_len != clen)
+                                       len_diffs++;
+                               if (zone->type != ctype)
+                                       type_diffs++;
                                ctype = zone->type;
                        }
-                       if (z_len != clen)
-                               len_diffs++;
-                       if (zone->type != ctype)
-                               type_diffs++;
-                       ctype = zone->type;
-               }
+                       progress = z_start + z_len;
 
-               /* shift to device units */
-               z_start >>= ilog2(sdkp->device->sector_size) - 9;
-               z_len >>= ilog2(sdkp->device->sector_size) - 9;
-               z_wp_abs >>= ilog2(sdkp->device->sector_size) - 9;
+                       if (!bzd) {
+                               if (bzrpt)
+                                       bzrpt->descriptor_count =
+                                               cpu_to_be32(++entry);
+                               continue;
+                       }
 
-               if (!bzd) {
+                       /* shift to device units */
+                       z_start >>= ilog2(sdp->sector_size) - 9;
+                       z_len >>= ilog2(sdp->sector_size) - 9;
+                       z_wp_abs >>= ilog2(sdp->sector_size) - 9;
+
+                       cond = zone->state;
+                       if (zone->type == BLK_ZONE_TYPE_CONVENTIONAL)
+                               flgs |= 0x02;
+                       else if (zone->wp)
+                               flgs |= 0x01; /* flag as RWP recommended? */
+
+                       dscr = &bzd[entry];
+                       dscr->lba_start = cpu_to_be64(z_start);
+                       dscr->length = cpu_to_be64(z_len);
+                       dscr->lba_wptr = cpu_to_be64(z_wp_abs);
+                       dscr->type = zone->type;
+                       dscr->flags = cond << 4 | flgs;
+                       entry++;
                        if (bzrpt)
-                               bzrpt->descriptor_count =
-                                       cpu_to_be32(++entry);
-                       continue;
+                               bzrpt->descriptor_count = cpu_to_be32(entry);
                }
-
-               bzd[entry].lba_start = cpu_to_be64(z_start);
-               bzd[entry].length = cpu_to_be64(z_len);
-               bzd[entry].lba_wptr = cpu_to_be64(z_wp_abs);
-               bzd[entry].type = zone->type;
-               bzd[entry].flags = cond << 4 | flgs;
-               entry++;
-               if (bzrpt)
-                       bzrpt->descriptor_count = cpu_to_be32(entry);
+               spin_unlock_irqrestore(&wpdscr->lock, flags);
        }
 
        /* if same code applies to all zones */
        if (bzrpt && !(opt & ZBC_REPORT_ZONE_PARTIAL)) {
-               for (node = rb_first(&q->zones); node; node = rb_next(node)) {
-                       zone = rb_entry(node, struct blk_zone, node);
-
-                       spin_lock_irqsave(&zone->lock, flags);
-                       if (clen != ~0ul) {
-                               clen = zone->len;
+               for (iter = 0; iter < zi->wps_count; iter++) {
+                       wpdscr = zi->wps[iter];
+                       spin_lock_irqsave(&wpdscr->lock, flags);
+                       for (idscr = 0; idscr < wpdscr->zone_count; idscr++) {
+                               z_len = wpdscr->zone_size;
+                               zone = &wpdscr->zones[idscr];
+                               if (clen != ~0ul) {
+                                       clen = z_len;
+                                       ctype = zone->type;
+                               }
+                               if (z_len != clen)
+                                       len_diffs++;
+                               if (zone->type != ctype)
+                                       type_diffs++;
                                ctype = zone->type;
                        }
-                       if (zone->len != clen)
-                               len_diffs++;
-                       if (zone->type != ctype)
-                               type_diffs++;
-                       ctype = zone->type;
-                       spin_unlock_irqrestore(&zone->lock, flags);
+                       spin_unlock_irqrestore(&wpdscr->lock, flags);
                }
        }
 
@@ -985,12 +913,15 @@ out:
 int sd_zbc_setup_read_write(struct scsi_disk *sdkp, struct request *rq,
                            sector_t sector, unsigned int *num_sectors)
 {
+       struct request_queue *q = sdkp->disk->queue;
        struct blk_zone *zone;
+       sector_t z_start, z_len;
+       spinlock_t *lck;
        unsigned int sectors = *num_sectors;
        int ret = BLKPREP_OK;
        unsigned long flags;
 
-       zone = blk_lookup_zone(sdkp->disk->queue, sector);
+       zone = blk_lookup_zone(q, sector, &z_start, &z_len, &lck);
        if (!zone) {
                /* Might happen during zone initialization */
                sd_zbc_debug_ratelimit(sdkp,
@@ -999,7 +930,7 @@ int sd_zbc_setup_read_write(struct scsi_disk *sdkp, struct 
request *rq,
                return BLKPREP_OK;
        }
 
-       spin_lock_irqsave(&zone->lock, flags);
+       spin_lock_irqsave(lck, flags);
 
        if (blk_zone_is_cmr(zone))
                goto out;
@@ -1008,7 +939,7 @@ int sd_zbc_setup_read_write(struct scsi_disk *sdkp, struct 
request *rq,
            zone->state == BLK_ZONE_BUSY) {
                sd_zbc_debug_ratelimit(sdkp,
                                       "zone %zu state %x, deferring\n",
-                                      zone->start, zone->state);
+                                      z_start, zone->state);
                ret = BLKPREP_DEFER;
                goto out;
        }
@@ -1017,25 +948,22 @@ int sd_zbc_setup_read_write(struct scsi_disk *sdkp, 
struct request *rq,
                if (op_is_write(req_op(rq))) {
                        u64 nwp = sector + sectors;
 
-                       while (nwp > (zone->start + zone->len)) {
-                               struct rb_node *node = rb_next(&zone->node);
+                       while (nwp > (z_start + z_len)) {
+                               zone->wp = z_len;
+                               sector = z_start + z_len;
+                               sectors = nwp - sector;
+                               spin_unlock_irqrestore(lck, flags);
 
-                               zone->wp = zone->start + zone->len;
-                               sector = zone->wp;
-                               sectors = nwp - zone->wp;
-                               spin_unlock_irqrestore(&zone->lock, flags);
-
-                               if (!node)
-                                       return BLKPREP_OK;
-                               zone = rb_entry(node, struct blk_zone, node);
+                               zone = blk_lookup_zone(q, sector,
+                                                      &z_start, &z_len, &lck);
                                if (!zone)
                                        return BLKPREP_OK;
 
-                               spin_lock_irqsave(&zone->lock, flags);
+                               spin_lock_irqsave(lck, flags);
                                nwp = sector + sectors;
                        }
-                       if (nwp > zone->wp)
-                               zone->wp = nwp;
+                       if (nwp > z_start + zone->wp)
+                               zone->wp = nwp - z_start;
                }
                goto out;
        }
@@ -1044,37 +972,37 @@ int sd_zbc_setup_read_write(struct scsi_disk *sdkp, 
struct request *rq,
                /* let the drive fail the command */
                sd_zbc_debug_ratelimit(sdkp,
                                       "zone %zu offline\n",
-                                      zone->start);
+                                      z_start);
                goto out;
        }
 
        if (op_is_write(req_op(rq))) {
                if (zone->state == BLK_ZONE_READONLY)
                        goto out;
-               if (blk_zone_is_full(zone)) {
+               if (zone->wp == z_len) {
                        sd_zbc_debug(sdkp,
-                                    "Write to full zone %zu/%zu\n",
-                                    sector, zone->wp);
+                                    "Write to full zone %zu/%zu/%zu\n",
+                                    sector, (sector_t)zone->wp, z_len);
                        ret = BLKPREP_KILL;
                        goto out;
                }
-               if (zone->wp != sector) {
+               if (sector != (z_start + zone->wp)) {
                        sd_zbc_debug(sdkp,
                                     "Misaligned write %zu/%zu\n",
-                                    sector, zone->wp);
+                                    sector, z_start + zone->wp);
                        ret = BLKPREP_KILL;
                        goto out;
                }
                zone->wp += sectors;
-       } else if (zone->wp <= sector + sectors) {
-               if (zone->wp <= sector) {
+       } else if (z_start + zone->wp <= sector + sectors) {
+               if (z_start + zone->wp <= sector) {
                        /* Read beyond WP: clear request buffer */
                        struct req_iterator iter;
                        struct bio_vec bvec;
                        void *buf;
                        sd_zbc_debug(sdkp,
                                     "Read beyond wp %zu+%u/%zu\n",
-                                    sector, sectors, zone->wp);
+                                    sector, sectors, z_start + zone->wp);
                        rq_for_each_segment(bvec, rq, iter) {
                                buf = bvec_kmap_irq(&bvec, &flags);
                                memset(buf, 0, bvec.bv_len);
@@ -1085,15 +1013,15 @@ int sd_zbc_setup_read_write(struct scsi_disk *sdkp, 
struct request *rq,
                        goto out;
                }
                /* Read straddle WP position: limit request size */
-               *num_sectors = zone->wp - sector;
+               *num_sectors = z_start + zone->wp - sector;
                sd_zbc_debug(sdkp,
                             "Read straddle wp %zu+%u/%zu => %zu+%u\n",
-                            sector, sectors, zone->wp,
+                            sector, sectors, z_start + zone->wp,
                             sector, *num_sectors);
        }
 
 out:
-       spin_unlock_irqrestore(&zone->lock, flags);
+       spin_unlock_irqrestore(lck, flags);
 
        return ret;
 }
@@ -1145,21 +1073,22 @@ static void update_zones_from_report(struct scsi_cmnd 
*cmd, u32 nr_bytes)
                        struct bdev_zone_descriptor *entry = &bzde[iter];
                        sector_t s = get_start_from_desc(sdkp, entry);
                        sector_t z_len = get_len_from_desc(sdkp, entry);
+                       sector_t z_strt;
+                       spinlock_t *lck;
                        unsigned long flags;
 
                        if (!z_len)
                                goto done;
 
-                       zone = blk_lookup_zone(rq->q, s);
+                       zone = blk_lookup_zone(rq->q, s, &z_strt, &z_len, &lck);
                        if (!zone)
                                goto done;
 
-                       spin_lock_irqsave(&zone->lock, flags);
+                       spin_lock_irqsave(lck, flags);
                        zone->type = entry->type & 0xF;
                        zone->state = (entry->flags >> 4) & 0xF;
                        zone->wp = get_wp_from_desc(sdkp, entry);
-                       zone->len = z_len;
-                       spin_unlock_irqrestore(&zone->lock, flags);
+                       spin_unlock_irqrestore(lck, flags);
                }
                nread += len;
                if (!dmax)
@@ -1233,113 +1162,314 @@ void sd_zbc_uninit_command(struct scsi_cmnd *cmd)
 }
 
 /**
- * sd_zbc_init - Load zones of matching zlen size into rb tree.
+ * alloc_cpws() - Allocate space for a contiguous set of write pointers
+ * @items: Number of wps needed.
+ * @lba: lba of the start of the next zone.
+ * @z_start: Starting lba of this contiguous set.
+ * @z_size: Size of each zone this contiguous set.
  *
+ * Return: Allocated wps or NULL on error.
  */
-static int sd_zbc_init(struct scsi_disk *sdkp, u64 zlen, char *buf, int 
buf_len)
+static struct contiguous_wps *alloc_cpws(int items, u64 lba, u64 z_start,
+                                        u64 z_size)
 {
-       sector_t capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
-       sector_t last_sector;
+       struct contiguous_wps *cwps = NULL;
+       size_t sz;
 
-       if (test_and_set_bit(SD_ZBC_ZONE_INIT, &sdkp->zone_flags)) {
-               sdev_printk(KERN_WARNING, sdkp->device,
-                           "zone initialization already running\n");
-               return 0;
+       sz = sizeof(struct contiguous_wps) + (items * sizeof(struct blk_zone));
+       if (items) {
+               cwps = vzalloc(sz);
+               if (!cwps)
+                       goto out;
+               spin_lock_init(&cwps->lock);
+               cwps->start_lba = z_start;
+               cwps->last_lba = lba - 1;
+               cwps->zone_size = z_size;
+               cwps->is_zoned = items > 1 ? 1 : 0;
+               cwps->zone_count = items;
        }
 
-       if (!sdkp->zone_work_q) {
-               char wq_name[32];
+out:
+       return cwps;
+}
 
-               sprintf(wq_name, "zbc_wq_%s", sdkp->disk->disk_name);
-               sdkp->zone_work_q = create_singlethread_workqueue(wq_name);
-               if (!sdkp->zone_work_q) {
-                       sdev_printk(KERN_WARNING, sdkp->device,
-                                   "create zoned disk workqueue failed\n");
-                       return -ENOMEM;
+/**
+ * free_zone_wps() - Free up memory in use by wps
+ * @zi: zone wps array(s).
+ */
+static void free_zone_wps(struct zone_wps *zi)
+{
+       /* on error free the arrays */
+       if (zi && zi->wps) {
+               int ca;
+
+               for (ca = 0; ca < zi->wps_count; ca++) {
+                       if (zi->wps[ca]) {
+                               vfree(zi->wps[ca]);
+                               zi->wps[ca] = NULL;
+                       }
                }
-       } else if (!test_and_set_bit(SD_ZBC_ZONE_RESET, &sdkp->zone_flags)) {
-               drain_workqueue(sdkp->zone_work_q);
-               clear_bit(SD_ZBC_ZONE_RESET, &sdkp->zone_flags);
+               kfree(zi->wps);
        }
+}
 
-       last_sector = zbc_parse_zones(sdkp, zlen, buf, buf_len);
-       capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
-       if (last_sector != -1 && last_sector < capacity) {
-               sd_zbc_update_zones(sdkp, last_sector,
-                                   SD_ZBC_BUF_SIZE, SD_ZBC_INIT);
-       } else
-               clear_bit(SD_ZBC_ZONE_INIT, &sdkp->zone_flags);
+static int wps_realloc(struct zone_wps *zi, gfp_t gfp_mask)
+{
+       int rcode = 0;
+       struct contiguous_wps **old;
+       struct contiguous_wps **tmp;
+       int n = zi->wps_count * 2;
+
+       old = zi->wps;
+       tmp = kzalloc(n, sizeof(*zi->wps), gfp_mask);
+       if (!tmp) {
+               rcode = -ENOMEM;
+               goto out;
+       }
+       memcpy(tmp, zi->wps, zi->wps_count * sizeof(*zi->wps));
+       zi->wps = tmp;
+       kfree(old);
 
-       return 0;
+out:
+       return rcode;
 }
 
+#define FMT_CHANGING_CAPACITY "Changing capacity from %zu to Max LBA+1 %zu"
+
 /**
- * sd_zbc_config() - Configure a ZBC device (on attach)
- * @sdkp: SCSI disk being attached.
- * @buffer: Buffer to working data.
- * @buf_sz: Size of buffer to use for working data
+ * zbc_init_zones() - Re-Sync expected WP location with drive
+ * @sdkp: scsi_disk
+ * @gfp_mask: Allocation mask.
  *
- * Return: true of SD_ZBC_RESET_WP provisioning is supported
+ * Return: 0 on success, otherwise error.
  */
-bool sd_zbc_config(struct scsi_disk *sdkp, void *buffer, size_t buf_sz)
+int zbc_init_zones(struct scsi_disk *sdkp, gfp_t gfp_mask)
 {
-       struct bdev_zone_report *bzrpt = buffer;
-       u64 zone_len, lba;
-       int retval;
-       u32 rep_len;
-       u8 same;
+       struct request_queue *q = sdkp->disk->queue;
+       int rcode = 0;
+       int entry = 0;
+       int offset;
+       int offmax;
+       u64 iter;
+       u64 z_start = 0ul;
+       u64 z_size = 0; /* size of zone */
+       int z_count = 0; /* number of zones of z_size */
+       int do_fill = 0;
+       int array_count = 0;
+       int one_time_setup = 0;
+       u8 opt = ZBC_ZONE_REPORTING_OPTION_ALL;
+       size_t bufsz = SD_ZBC_BUF_SIZE;
+       struct bdev_zone_report *rpt = NULL;
+       struct zone_wps *zi = NULL;
+       struct contiguous_wps *cwps = NULL;
+
+       if (q->zones)
+               goto out;
 
-       if (sdkp->zoned != 1 && sdkp->device->type != TYPE_ZBC)
-               /*
-                * Device managed or normal SCSI disk,
-                * no special handling required
-                */
-               return false;
-
-       retval = sd_zbc_report_zones(sdkp, bzrpt, buf_sz,
-                                    0, ZBC_ZONE_REPORTING_OPTION_ALL, false);
-       if (retval < 0)
-               return false;
-
-       rep_len = be32_to_cpu(bzrpt->descriptor_count);
-       if (rep_len < 7) {
-               sd_printk(KERN_WARNING, sdkp,
-                         "REPORT ZONES report invalid length %u\n",
-                         rep_len);
-               return false;
+       zi = kzalloc(sizeof(*zi), gfp_mask);
+       if (!zi) {
+               rcode = -ENOMEM;
+               goto out;
        }
 
-       if (sdkp->rc_basis == 0) {
-               /* The max_lba field is the capacity of a zoned device */
-               lba = be64_to_cpu(bzrpt->maximum_lba);
-               if (lba + 1 > sdkp->capacity) {
-                       if (sdkp->first_scan)
-                               sd_printk(KERN_WARNING, sdkp,
-                                         "Changing capacity from %zu to Max 
LBA+1 %zu\n",
-                                         sdkp->capacity, (sector_t) lba + 1);
-                       sdkp->capacity = lba + 1;
+       if (sdkp->zoned != 1 && sdkp->device->type != TYPE_ZBC) {
+               struct gendisk *disk = sdkp->disk;
+
+               zi->wps = kzalloc(sizeof(*zi->wps), gfp_mask);
+               zi->wps[0] = alloc_cpws(1, disk->part0.nr_sects, z_start, 1);
+               if (!zi->wps[0]) {
+                       rcode = -ENOMEM;
+                       goto out;
                }
+               zi->wps_count = 1;
+               goto out;
+       }
+
+       rpt = kmalloc(bufsz, gfp_mask);
+       if (!rpt) {
+               rcode = -ENOMEM;
+               goto out;
        }
 
        /*
-        * Adjust 'chunk_sectors' to the zone length if the device
-        * supports equal zone sizes.
+        * Start by handling upto 32 different zone sizes. 2 will work
+        * for all the current drives, but maybe something exotic will
+        * surface.
         */
-       same = bzrpt->same_field & 0x0f;
-       if (same > 3) {
-               sd_printk(KERN_WARNING, sdkp,
-                         "REPORT ZONES SAME type %d not supported\n", same);
-               return false;
+       zi->wps = kcalloc(32, sizeof(*zi->wps), gfp_mask);
+       zi->wps_count = 32;
+       if (!zi->wps) {
+               rcode = -ENOMEM;
+               goto out;
        }
-       /* Read the zone length from the first zone descriptor */
-       zone_len = be64_to_cpu(bzrpt->descriptors[0].length);
-       sdkp->unmap_alignment = zone_len;
-       sdkp->unmap_granularity = zone_len;
-       blk_queue_chunk_sectors(sdkp->disk->queue,
-                               logical_to_sectors(sdkp->device, zone_len));
-
-       sd_zbc_init(sdkp, zone_len, buffer, buf_sz);
-       return true;
+
+fill:
+       offset = 0;
+       offmax = 0;
+       for (entry = 0, iter = 0; iter < sdkp->capacity; entry++) {
+               struct bdev_zone_descriptor *bzde;
+               int stop_end = 0;
+               int stop_size = 0;
+
+               if (offset == 0) {
+                       int err;
+
+                       err = sd_zbc_report_zones(sdkp, rpt, bufsz, iter, opt);
+                       if (err) {
+                               pr_err("report zones-> %d\n", err);
+                               if (err != -ENOTSUPP)
+                                       rcode = err;
+                               goto out;
+                       }
+                       if (sdkp->rc_basis == 0) {
+                               sector_t lba = be64_to_cpu(rpt->maximum_lba);
+
+                               if (lba + 1 > sdkp->capacity) {
+                                       sd_printk(KERN_WARNING, sdkp,
+                                                 FMT_CHANGING_CAPACITY "\n",
+                                                 sdkp->capacity, lba + 1);
+                                       sdkp->capacity = lba + 1;
+                               }
+                       }
+                       offmax = max_report_entries(bufsz);
+               }
+               bzde = &rpt->descriptors[offset];
+               if (z_size == 0)
+                       z_size = get_len_from_desc(sdkp, bzde);
+               if (z_size != get_len_from_desc(sdkp, bzde))
+                       stop_size = 1;
+               if ((iter + z_size) >= sdkp->capacity)
+                       stop_end = 1;
+
+               if (!one_time_setup) {
+                       u8 type = bzde->type & 0x0F;
+
+                       if (type != BLK_ZONE_TYPE_CONVENTIONAL) {
+                               one_time_setup = 1;
+                               blk_queue_chunk_sectors(sdkp->disk->queue,
+                                                       z_size);
+                       }
+               }
+
+               if (do_fill == 0) {
+                       if (stop_end || stop_size) {
+                               /* include the next/last zone? */
+                               if (!stop_size) {
+                                       z_count++;
+                                       iter += z_size;
+                               }
+                               cwps = alloc_cpws(z_count, iter,
+                                                 z_start, z_size);
+                               if (!cwps) {
+                                       rcode = -ENOMEM;
+                                       goto out;
+                               }
+                               if (array_count > 0)
+                                       cwps->is_zoned = 1;
+
+                               zi->wps[array_count] = cwps;
+                               z_start = iter;
+                               z_size = 0;
+                               z_count = 0;
+                               array_count++;
+                               if (array_count >= zi->wps_count) {
+                                       rcode = wps_realloc(zi, gfp_mask);
+                                       if (rcode)
+                                               goto out;
+                               }
+                               /* add the runt zone */
+                               if (stop_end && stop_size) {
+                                       z_count++;
+                                       z_size = get_len_from_desc(sdkp, bzde);
+                                       cwps = alloc_cpws(z_count,
+                                                         iter + z_size,
+                                                         z_start, z_size);
+                                       if (!cwps) {
+                                               rcode = -ENOMEM;
+                                               goto out;
+                                       }
+                                       if (array_count > 0)
+                                               cwps->is_zoned = 1;
+                                       zi->wps[array_count] = cwps;
+                                       array_count++;
+                               }
+                               if (stop_end) {
+                                       do_fill = 1;
+                                       array_count = 0;
+                                       z_count = 0;
+                                       z_size = 0;
+                                       goto fill;
+                               }
+                       }
+                       z_size = get_len_from_desc(sdkp, bzde);
+                       iter += z_size;
+                       z_count++;
+               } else {
+                       fill_zone(zi->wps[array_count], z_count, sdkp, bzde);
+                       z_count++;
+                       iter += z_size;
+                       if (zi->wps[array_count]->zone_count == z_count) {
+                               z_count = 0;
+                               array_count++;
+                               zi->wps_count = array_count;
+                       }
+               }
+               offset++;
+               if (offset >= offmax)
+                       offset = 0;
+       }
+out:
+       kfree(rpt);
+
+       if (rcode) {
+               if (zi) {
+                       free_zone_wps(zi);
+                       kfree(zi);
+               }
+       } else {
+               q->zones = zi;
+       }
+
+       return rcode;
+}
+
+/**
+ * sd_zbc_config() - Configure a ZBC device (on attach)
+ * @sdkp: SCSI disk being attached.
+ * @gfp_mask: Memory allocation strategy
+ *
+ * Return: true of SD_ZBC_RESET_WP provisioning is supported
+ */
+bool sd_zbc_config(struct scsi_disk *sdkp, gfp_t gfp_mask)
+{
+       bool can_reset_wp = false;
+
+       if (zbc_init_zones(sdkp, gfp_mask)) {
+               sdev_printk(KERN_WARNING, sdkp->device,
+                           "Initialize zone cache failed\n");
+               goto out;
+       }
+
+       if (sdkp->zoned == 1 || sdkp->device->type == TYPE_ZBC)
+               can_reset_wp = true;
+
+       if (!sdkp->zone_work_q) {
+               char wq_name[32];
+
+               sprintf(wq_name, "zbc_wq_%s", sdkp->disk->disk_name);
+               sdkp->zone_work_q = create_singlethread_workqueue(wq_name);
+               if (!sdkp->zone_work_q) {
+                       sdev_printk(KERN_WARNING, sdkp->device,
+                                   "create zoned disk workqueue failed\n");
+                       goto out;
+               }
+       } else if (!test_and_set_bit(SD_ZBC_ZONE_RESET, &sdkp->zone_flags)) {
+               drain_workqueue(sdkp->zone_work_q);
+               clear_bit(SD_ZBC_ZONE_RESET, &sdkp->zone_flags);
+       }
+
+out:
+       return can_reset_wp;
 }
 
 /**
@@ -1365,15 +1495,16 @@ void sd_zbc_remove(struct scsi_disk *sdkp)
  */
 unsigned int sd_zbc_discard_granularity(struct scsi_disk *sdkp)
 {
-       unsigned int bytes = 1;
        struct request_queue *q = sdkp->disk->queue;
-       struct rb_node *node = rb_first(&q->zones);
+       struct zone_wps *zi = q->zones;
+       unsigned int bytes = 1;
 
-       if (node) {
-               struct blk_zone *zone = rb_entry(node, struct blk_zone, node);
+       if (zi && zi->wps_count > 0) {
+               struct contiguous_wps *wp = zi->wps[0];
 
-               bytes = zone->len;
+               bytes = wp->zone_size;
        }
+
        bytes <<= ilog2(sdkp->device->sector_size);
        return bytes;
 }
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d5cdb5d..113c5a8 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -264,27 +264,83 @@ struct blk_queue_tag {
 
 #ifdef CONFIG_BLK_DEV_ZONED
 
+/**
+ * struct blk_zone - A single zone type/stats and WP offset.
+ *
+ * @wp:    Holds the wp offset from the start of the zone.
+ * @type:  Holds the zone type nibble.
+ * @state: Holds the zone state nibble + kernel (zone busy)
+ * @private_data: Used to hold whatever the implicit domain owner
+ *                of the zone needs to track.
+ *
+ * Type is left at 4 bits (only 2 are needed currently) to match
+ * the current ZBC/ZAC standards.
+ *
+ * State is using 5 bits to accommodate the ZONE_BUSY. The first 4 bits
+ * match the current ZBC/ZAC spec.
+ * ZONE_BUSY could be mapped to one of the reserved bits. Using it as
+ * mask bit or independent flag my be useful for decoding the zone
+ * state before it transitioned to BUSY.
+ *
+ * A zone sized at order (39+9) is very unlikely (current zones are 16+9)
+ * Even at lba48 equivalent number of sectors we have a large amount
+ * of padding to fill out 8 bytes.
+ *
+ * Getting this to fit in 4 bytes would limit the maximum size of a zone
+ * to 4G [order 23 of 512 byte sectors + 9 bits for flags] which is probably
+ * okay for embedded or 32-bit systems where the private_data pointer
+ * would also shrink to 32 bits. There are also WP tracking schemes
+ * that don't make use of the private_data helper so perhaps that
+ * could be factored out as well.
+ */
 struct blk_zone {
-       struct rb_node node;
-       spinlock_t lock;
-       sector_t start;
-       size_t len;
-       sector_t wp;
-       enum blk_zone_type type;
-       enum blk_zone_state state;
+       unsigned long long wp:39;
+       unsigned long long type:4;
+       unsigned long long state:5;
+       unsigned long long padding:15;
        void *private_data;
 };
 
+/**
+ * struct contiguous_wps - A descriptor of zones of the same size
+ *
+ * @start_lba:  LBA of first zone covered by the descriptor.
+ * @last_lba:   LBA of last zone.
+ * @zone_size:  Size of zones as a number of 512 byte sectors.
+ * @zone_count: Number of zones (last-start/size) for convenience.
+ * @lock:       A spinlock protecting these zones.
+ * @is_zoned:   0 when all zones are conventional no WP zones.
+ * zones:       Array of blk_zone entries.
+ */
+struct contiguous_wps {
+       u64 start_lba;
+       u64 last_lba;
+       u64 zone_size;
+       u32 zone_count;
+       spinlock_t lock;
+       unsigned is_zoned:1;
+       struct blk_zone zones[0];
+};
+
+/**
+ * struct zone_wps - A collection of zone descriptors to describe zoned media.
+ *
+ * @wps_count:  Number of descriptors.
+ * @wps:        Array of zone descriptors.
+ */
+struct zone_wps {
+       u32 wps_count;
+       struct contiguous_wps **wps;
+};
+
 #define blk_zone_is_seq_req(z) ((z)->type == BLK_ZONE_TYPE_SEQWRITE_REQ)
 #define blk_zone_is_seq_pref(z) ((z)->type == BLK_ZONE_TYPE_SEQWRITE_PREF)
 #define blk_zone_is_smr(z) (blk_zone_is_seq_req(z) || blk_zone_is_seq_pref(z))
 #define blk_zone_is_cmr(z) ((z)->type == BLK_ZONE_TYPE_CONVENTIONAL)
-#define blk_zone_is_full(z) ((z)->wp == (z)->start + (z)->len)
-#define blk_zone_is_empty(z) ((z)->wp == (z)->start)
+#define blk_zone_is_empty(z) ((z)->wp == 0)
 
-extern struct blk_zone *blk_lookup_zone(struct request_queue *, sector_t);
-extern struct blk_zone *blk_insert_zone(struct request_queue *,
-                                       struct blk_zone *);
+extern struct blk_zone *blk_lookup_zone(struct request_queue *, sector_t,
+                                       sector_t *, sector_t *, spinlock_t **);
 extern void blk_drop_zones(struct request_queue *);
 #else
 static inline void blk_drop_zones(struct request_queue *q) { };
@@ -463,7 +519,7 @@ struct request_queue {
        struct queue_limits     limits;
 
 #ifdef CONFIG_BLK_DEV_ZONED
-       struct rb_root          zones;
+       struct zone_wps         *zones;
 #endif
        /*
         * sg stuff
-- 
2.9.3

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