From: Hannes Reinecke <h...@suse.de>

Implement ZBC support functions to setup zoned disks, both
host-managed and host-aware models. Only zoned disks that satisfy
the following conditions are supported:
1) All zones are the same size, with the exception of an eventual
   last smaller runt zone.
2) For host-managed disks, reads are unrestricted (reads are not
   failed due to zone or write pointer alignement constraints).
Zoned disks that do not satisfy these 2 conditions are setup with
a capacity of 0 to prevent their use.

The function sd_zbc_read_zones, called from sd_revalidate_disk,
checks that the device satisfies the above two constraints. This
function may also change the disk capacity previously set by
sd_read_capacity for devices reporting only the capacity of
conventional zones at the beginning of the LBA range (i.e. devices
reporting rc_basis set to 0).

The capacity message output was moved out of sd_read_capacity into
a new function sd_print_capacity to include this eventual capacity
change by sd_zbc_read_zones. This new function also includes a call
to sd_zbc_print_zones to display the number of zones and zone size
of the device.

Signed-off-by: Hannes Reinecke <h...@suse.de>

[Damien: * Removed zone cache support
         * Removed mapping of discard to reset write pointer command
         * Modified sd_zbc_read_zones to include checks that the
           device satisfies the kernel constraints
         * Implemeted REPORT ZONES setup and post-processing based
           on code from Shaun Tancheff <shaun.tanch...@seagate.com>
         * Removed confusing use of 512B sector units in functions
           interface]
Signed-off-by: Damien Le Moal <damien.lem...@hgst.com>
Reviewed-by: Christoph Hellwig <h...@lst.de>
Reviewed-by: Shaun Tancheff <shaun.tanch...@seagate.com>
Tested-by: Shaun Tancheff <shaun.tanch...@seagate.com>

---
 drivers/scsi/Makefile     |   1 +
 drivers/scsi/sd.c         | 141 ++++++++---
 drivers/scsi/sd.h         |  67 +++++
 drivers/scsi/sd_zbc.c     | 627 ++++++++++++++++++++++++++++++++++++++++++++++
 include/scsi/scsi_proto.h |  17 ++
 5 files changed, 820 insertions(+), 33 deletions(-)
 create mode 100644 drivers/scsi/sd_zbc.c

diff --git a/drivers/scsi/Makefile b/drivers/scsi/Makefile
index fc0d9b8..350513c 100644
--- a/drivers/scsi/Makefile
+++ b/drivers/scsi/Makefile
@@ -180,6 +180,7 @@ hv_storvsc-y                        := storvsc_drv.o
 
 sd_mod-objs    := sd.o
 sd_mod-$(CONFIG_BLK_DEV_INTEGRITY) += sd_dif.o
+sd_mod-$(CONFIG_BLK_DEV_ZONED) += sd_zbc.o
 
 sr_mod-objs    := sr.o sr_ioctl.o sr_vendor.o
 ncr53c8xx-flags-$(CONFIG_SCSI_ZALON) \
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 51e5629..20889b5 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -93,6 +93,7 @@ MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_DISK15_MAJOR);
 MODULE_ALIAS_SCSI_DEVICE(TYPE_DISK);
 MODULE_ALIAS_SCSI_DEVICE(TYPE_MOD);
 MODULE_ALIAS_SCSI_DEVICE(TYPE_RBC);
+MODULE_ALIAS_SCSI_DEVICE(TYPE_ZBC);
 
 #if !defined(CONFIG_DEBUG_BLOCK_EXT_DEVT)
 #define SD_MINORS      16
@@ -163,7 +164,7 @@ cache_type_store(struct device *dev, struct 
device_attribute *attr,
        static const char temp[] = "temporary ";
        int len;
 
-       if (sdp->type != TYPE_DISK)
+       if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
                /* no cache control on RBC devices; theoretically they
                 * can do it, but there's probably so many exceptions
                 * it's not worth the risk */
@@ -262,7 +263,7 @@ allow_restart_store(struct device *dev, struct 
device_attribute *attr,
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
 
-       if (sdp->type != TYPE_DISK)
+       if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
                return -EINVAL;
 
        sdp->allow_restart = simple_strtoul(buf, NULL, 10);
@@ -392,6 +393,11 @@ provisioning_mode_store(struct device *dev, struct 
device_attribute *attr,
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
 
+       if (sd_is_zoned(sdkp)) {
+               sd_config_discard(sdkp, SD_LBP_DISABLE);
+               return count;
+       }
+
        if (sdp->type != TYPE_DISK)
                return -EINVAL;
 
@@ -459,7 +465,7 @@ max_write_same_blocks_store(struct device *dev, struct 
device_attribute *attr,
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
 
-       if (sdp->type != TYPE_DISK)
+       if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
                return -EINVAL;
 
        err = kstrtoul(buf, 10, &max);
@@ -844,6 +850,12 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 
        BUG_ON(bio_offset(bio) || bio_iovec(bio).bv_len != sdp->sector_size);
 
+       if (sd_is_zoned(sdkp)) {
+               ret = sd_zbc_setup_read_write(cmd);
+               if (ret != BLKPREP_OK)
+                       return ret;
+       }
+
        sector >>= ilog2(sdp->sector_size) - 9;
        nr_sectors >>= ilog2(sdp->sector_size) - 9;
 
@@ -963,6 +975,12 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd 
*SCpnt)
        SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
                                        (unsigned long long)block));
 
+       if (sd_is_zoned(sdkp)) {
+               ret = sd_zbc_setup_read_write(SCpnt);
+               if (ret != BLKPREP_OK)
+                       goto out;
+       }
+
        /*
         * If we have a 1K hardware sectorsize, prevent access to single
         * 512 byte sectors.  In theory we could handle this - in fact
@@ -1149,6 +1167,10 @@ static int sd_init_command(struct scsi_cmnd *cmd)
        case REQ_OP_READ:
        case REQ_OP_WRITE:
                return sd_setup_read_write_cmnd(cmd);
+       case REQ_OP_ZONE_REPORT:
+               return sd_zbc_setup_report_cmnd(cmd);
+       case REQ_OP_ZONE_RESET:
+               return sd_zbc_setup_reset_cmnd(cmd);
        default:
                BUG();
        }
@@ -1780,7 +1802,10 @@ static int sd_done(struct scsi_cmnd *SCpnt)
        unsigned char op = SCpnt->cmnd[0];
        unsigned char unmap = SCpnt->cmnd[1] & 8;
 
-       if (req_op(req) == REQ_OP_DISCARD || req_op(req) == REQ_OP_WRITE_SAME) {
+       switch (req_op(req)) {
+       case REQ_OP_DISCARD:
+       case REQ_OP_WRITE_SAME:
+       case REQ_OP_ZONE_RESET:
                if (!result) {
                        good_bytes = blk_rq_bytes(req);
                        scsi_set_resid(SCpnt, 0);
@@ -1788,6 +1813,17 @@ static int sd_done(struct scsi_cmnd *SCpnt)
                        good_bytes = 0;
                        scsi_set_resid(SCpnt, blk_rq_bytes(req));
                }
+               break;
+       case REQ_OP_ZONE_REPORT:
+               if (!result) {
+                       good_bytes = scsi_bufflen(SCpnt)
+                               - scsi_get_resid(SCpnt);
+                       scsi_set_resid(SCpnt, 0);
+               } else {
+                       good_bytes = 0;
+                       scsi_set_resid(SCpnt, blk_rq_bytes(req));
+               }
+               break;
        }
 
        if (result) {
@@ -1848,7 +1884,11 @@ static int sd_done(struct scsi_cmnd *SCpnt)
        default:
                break;
        }
+
  out:
+       if (sd_is_zoned(sdkp))
+               sd_zbc_complete(SCpnt, good_bytes, &sshdr);
+
        SCSI_LOG_HLCOMPLETE(1, scmd_printk(KERN_INFO, SCpnt,
                                           "sd_done: completed %d of %d 
bytes\n",
                                           good_bytes, scsi_bufflen(SCpnt)));
@@ -1983,7 +2023,6 @@ sd_spinup_disk(struct scsi_disk *sdkp)
        }
 }
 
-
 /*
  * Determine whether disk supports Data Integrity Field.
  */
@@ -2133,6 +2172,9 @@ static int read_capacity_16(struct scsi_disk *sdkp, 
struct scsi_device *sdp,
        /* Logical blocks per physical block exponent */
        sdkp->physical_block_size = (1 << (buffer[13] & 0xf)) * sector_size;
 
+       /* RC basis */
+       sdkp->rc_basis = (buffer[12] >> 4) & 0x3;
+
        /* Lowest aligned logical block */
        alignment = ((buffer[14] & 0x3f) << 8 | buffer[15]) * sector_size;
        blk_queue_alignment_offset(sdp->request_queue, alignment);
@@ -2242,7 +2284,6 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char 
*buffer)
 {
        int sector_size;
        struct scsi_device *sdp = sdkp->device;
-       sector_t old_capacity = sdkp->capacity;
 
        if (sd_try_rc16_first(sdp)) {
                sector_size = read_capacity_16(sdkp, sdp, buffer);
@@ -2323,35 +2364,44 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char 
*buffer)
                sector_size = 512;
        }
        blk_queue_logical_block_size(sdp->request_queue, sector_size);
+       blk_queue_physical_block_size(sdp->request_queue,
+                                     sdkp->physical_block_size);
+       sdkp->device->sector_size = sector_size;
 
-       {
-               char cap_str_2[10], cap_str_10[10];
+       if (sdkp->capacity > 0xffffffff)
+               sdp->use_16_for_rw = 1;
 
-               string_get_size(sdkp->capacity, sector_size,
-                               STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
-               string_get_size(sdkp->capacity, sector_size,
-                               STRING_UNITS_10, cap_str_10,
-                               sizeof(cap_str_10));
+}
 
-               if (sdkp->first_scan || old_capacity != sdkp->capacity) {
-                       sd_printk(KERN_NOTICE, sdkp,
-                                 "%llu %d-byte logical blocks: (%s/%s)\n",
-                                 (unsigned long long)sdkp->capacity,
-                                 sector_size, cap_str_10, cap_str_2);
+/*
+ * Print disk capacity
+ */
+static void
+sd_print_capacity(struct scsi_disk *sdkp,
+                 sector_t old_capacity)
+{
+       int sector_size = sdkp->device->sector_size;
+       char cap_str_2[10], cap_str_10[10];
 
-                       if (sdkp->physical_block_size != sector_size)
-                               sd_printk(KERN_NOTICE, sdkp,
-                                         "%u-byte physical blocks\n",
-                                         sdkp->physical_block_size);
-               }
-       }
+       string_get_size(sdkp->capacity, sector_size,
+                       STRING_UNITS_2, cap_str_2, sizeof(cap_str_2));
+       string_get_size(sdkp->capacity, sector_size,
+                       STRING_UNITS_10, cap_str_10,
+                       sizeof(cap_str_10));
 
-       if (sdkp->capacity > 0xffffffff)
-               sdp->use_16_for_rw = 1;
+       if (sdkp->first_scan || old_capacity != sdkp->capacity) {
+               sd_printk(KERN_NOTICE, sdkp,
+                         "%llu %d-byte logical blocks: (%s/%s)\n",
+                         (unsigned long long)sdkp->capacity,
+                         sector_size, cap_str_10, cap_str_2);
 
-       blk_queue_physical_block_size(sdp->request_queue,
-                                     sdkp->physical_block_size);
-       sdkp->device->sector_size = sector_size;
+               if (sdkp->physical_block_size != sector_size)
+                       sd_printk(KERN_NOTICE, sdkp,
+                                 "%u-byte physical blocks\n",
+                                 sdkp->physical_block_size);
+
+               sd_zbc_print_zones(sdkp);
+       }
 }
 
 /* called with buffer of length 512 */
@@ -2613,7 +2663,7 @@ static void sd_read_app_tag_own(struct scsi_disk *sdkp, 
unsigned char *buffer)
        struct scsi_mode_data data;
        struct scsi_sense_hdr sshdr;
 
-       if (sdp->type != TYPE_DISK)
+       if (sdp->type != TYPE_DISK && sdp->type != TYPE_ZBC)
                return;
 
        if (sdkp->protection_type == 0)
@@ -2720,6 +2770,7 @@ static void sd_read_block_limits(struct scsi_disk *sdkp)
  */
 static void sd_read_block_characteristics(struct scsi_disk *sdkp)
 {
+       struct request_queue *q = sdkp->disk->queue;
        unsigned char *buffer;
        u16 rot;
        const int vpd_len = 64;
@@ -2734,10 +2785,21 @@ static void sd_read_block_characteristics(struct 
scsi_disk *sdkp)
        rot = get_unaligned_be16(&buffer[4]);
 
        if (rot == 1) {
-               queue_flag_set_unlocked(QUEUE_FLAG_NONROT, sdkp->disk->queue);
-               queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, 
sdkp->disk->queue);
+               queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
+               queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
        }
 
+       sdkp->zoned = (buffer[8] >> 4) & 3;
+       if (sdkp->zoned == 1)
+               q->limits.zoned = BLK_ZONED_HA;
+       else if (sdkp->device->type == TYPE_ZBC)
+               q->limits.zoned = BLK_ZONED_HM;
+       else
+               q->limits.zoned = BLK_ZONED_NONE;
+       if (blk_queue_is_zoned(q) && sdkp->first_scan)
+               sd_printk(KERN_NOTICE, sdkp, "Host-%s zoned block device\n",
+                     q->limits.zoned == BLK_ZONED_HM ? "managed" : "aware");
+
  out:
        kfree(buffer);
 }
@@ -2809,6 +2871,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
        struct scsi_disk *sdkp = scsi_disk(disk);
        struct scsi_device *sdp = sdkp->device;
        struct request_queue *q = sdkp->disk->queue;
+       sector_t old_capacity = sdkp->capacity;
        unsigned char *buffer;
        unsigned int dev_max, rw_max;
 
@@ -2842,8 +2905,11 @@ static int sd_revalidate_disk(struct gendisk *disk)
                        sd_read_block_provisioning(sdkp);
                        sd_read_block_limits(sdkp);
                        sd_read_block_characteristics(sdkp);
+                       sd_zbc_read_zones(sdkp, buffer);
                }
 
+               sd_print_capacity(sdkp, old_capacity);
+
                sd_read_write_protect_flag(sdkp, buffer);
                sd_read_cache_type(sdkp, buffer);
                sd_read_app_tag_own(sdkp, buffer);
@@ -3041,9 +3107,16 @@ static int sd_probe(struct device *dev)
 
        scsi_autopm_get_device(sdp);
        error = -ENODEV;
-       if (sdp->type != TYPE_DISK && sdp->type != TYPE_MOD && sdp->type != 
TYPE_RBC)
+       if (sdp->type != TYPE_DISK &&
+           sdp->type != TYPE_ZBC &&
+           sdp->type != TYPE_MOD &&
+           sdp->type != TYPE_RBC)
                goto out;
 
+#ifndef CONFIG_BLK_DEV_ZONED
+       if (sdp->type == TYPE_ZBC)
+               goto out;
+#endif
        SCSI_LOG_HLQUEUE(3, sdev_printk(KERN_INFO, sdp,
                                        "sd_probe\n"));
 
@@ -3147,6 +3220,8 @@ static int sd_remove(struct device *dev)
        del_gendisk(sdkp->disk);
        sd_shutdown(dev);
 
+       sd_zbc_remove(sdkp);
+
        blk_register_region(devt, SD_MINORS, NULL,
                            sd_default_probe, NULL, NULL);
 
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index c8d9863..b48e7d8 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -64,6 +64,15 @@ struct scsi_disk {
        struct scsi_device *device;
        struct device   dev;
        struct gendisk  *disk;
+#ifdef CONFIG_BLK_DEV_ZONED
+       unsigned int    nr_zones;
+       unsigned int    zone_blocks;
+       unsigned int    zone_shift;
+       unsigned long   *zones_wlock;
+       unsigned int    zones_optimal_open;
+       unsigned int    zones_optimal_nonseq;
+       unsigned int    zones_max_open;
+#endif
        atomic_t        openers;
        sector_t        capacity;       /* size in logical blocks */
        u32             max_xfer_blocks;
@@ -94,6 +103,9 @@ struct scsi_disk {
        unsigned        lbpvpd : 1;
        unsigned        ws10 : 1;
        unsigned        ws16 : 1;
+       unsigned        rc_basis: 2;
+       unsigned        zoned: 2;
+       unsigned        urswrz : 1;
 };
 #define to_scsi_disk(obj) container_of(obj,struct scsi_disk,dev)
 
@@ -156,6 +168,11 @@ static inline unsigned int logical_to_bytes(struct 
scsi_device *sdev, sector_t b
        return blocks * sdev->sector_size;
 }
 
+static inline sector_t sectors_to_logical(struct scsi_device *sdev, sector_t 
sector)
+{
+       return sector >> (ilog2(sdev->sector_size) - 9);
+}
+
 /*
  * Look up the DIX operation based on whether the command is read or
  * write and whether dix and dif are enabled.
@@ -239,4 +256,54 @@ static inline void sd_dif_complete(struct scsi_cmnd *cmd, 
unsigned int a)
 
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
+static inline int sd_is_zoned(struct scsi_disk *sdkp)
+{
+       return sdkp->zoned == 1 || sdkp->device->type == TYPE_ZBC;
+}
+
+#ifdef CONFIG_BLK_DEV_ZONED
+
+extern int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buffer);
+extern void sd_zbc_remove(struct scsi_disk *sdkp);
+extern void sd_zbc_print_zones(struct scsi_disk *sdkp);
+extern int sd_zbc_setup_read_write(struct scsi_cmnd *cmd);
+extern int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd);
+extern int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd);
+extern void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
+                           struct scsi_sense_hdr *sshdr);
+
+#else /* CONFIG_BLK_DEV_ZONED */
+
+static inline int sd_zbc_read_zones(struct scsi_disk *sdkp,
+                                   unsigned char *buf)
+{
+       return 0;
+}
+
+static inline void sd_zbc_remove(struct scsi_disk *sdkp) {}
+
+static inline void sd_zbc_print_zones(struct scsi_disk *sdkp) {}
+
+static inline int sd_zbc_setup_read_write(struct scsi_cmnd *cmd)
+{
+       /* Let the drive fail requests */
+       return BLKPREP_OK;
+}
+
+static inline int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd)
+{
+       return BLKPREP_KILL;
+}
+
+static inline int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
+{
+       return BLKPREP_KILL;
+}
+
+static inline void sd_zbc_complete(struct scsi_cmnd *cmd,
+                                  unsigned int good_bytes,
+                                  struct scsi_sense_hdr *sshdr) {}
+
+#endif /* CONFIG_BLK_DEV_ZONED */
+
 #endif /* _SCSI_DISK_H */
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
new file mode 100644
index 0000000..54ecdaa9
--- /dev/null
+++ b/drivers/scsi/sd_zbc.c
@@ -0,0 +1,627 @@
+/*
+ * SCSI Zoned Block commands
+ *
+ * Copyright (C) 2014-2015 SUSE Linux GmbH
+ * Written by: Hannes Reinecke <h...@suse.de>
+ * Modified by: Damien Le Moal <damien.lem...@hgst.com>
+ * Modified by: Shaun Tancheff <shaun.tanch...@seagate.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
+ * USA.
+ *
+ */
+
+#include <linux/blkdev.h>
+
+#include <asm/unaligned.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_dbg.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_driver.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_eh.h>
+
+#include "sd.h"
+#include "scsi_priv.h"
+
+enum zbc_zone_type {
+       ZBC_ZONE_TYPE_CONV = 0x1,
+       ZBC_ZONE_TYPE_SEQWRITE_REQ,
+       ZBC_ZONE_TYPE_SEQWRITE_PREF,
+       ZBC_ZONE_TYPE_RESERVED,
+};
+
+enum zbc_zone_cond {
+       ZBC_ZONE_COND_NO_WP,
+       ZBC_ZONE_COND_EMPTY,
+       ZBC_ZONE_COND_IMP_OPEN,
+       ZBC_ZONE_COND_EXP_OPEN,
+       ZBC_ZONE_COND_CLOSED,
+       ZBC_ZONE_COND_READONLY = 0xd,
+       ZBC_ZONE_COND_FULL,
+       ZBC_ZONE_COND_OFFLINE,
+};
+
+/**
+ * Convert a zone descriptor to a zone struct.
+ */
+static void sd_zbc_parse_report(struct scsi_disk *sdkp,
+                               u8 *buf,
+                               struct blk_zone *zone)
+{
+       struct scsi_device *sdp = sdkp->device;
+
+       memset(zone, 0, sizeof(struct blk_zone));
+
+       zone->type = buf[0] & 0x0f;
+       zone->cond = (buf[1] >> 4) & 0xf;
+       if (buf[1] & 0x01)
+               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;
+}
+
+/**
+ * Issue a REPORT ZONES scsi command.
+ */
+static int sd_zbc_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
+                              unsigned int buflen, sector_t lba)
+{
+       struct scsi_device *sdp = sdkp->device;
+       const int timeout = sdp->request_queue->rq_timeout;
+       struct scsi_sense_hdr sshdr;
+       unsigned char cmd[16];
+       unsigned int rep_len;
+       int result;
+
+       memset(cmd, 0, 16);
+       cmd[0] = ZBC_IN;
+       cmd[1] = ZI_REPORT_ZONES;
+       put_unaligned_be64(lba, &cmd[2]);
+       put_unaligned_be32(buflen, &cmd[10]);
+       memset(buf, 0, buflen);
+
+       result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
+                                 buf, buflen, &sshdr,
+                                 timeout, SD_MAX_RETRIES, NULL);
+       if (result) {
+               sd_printk(KERN_ERR, sdkp,
+                         "REPORT ZONES lba %llu failed with %d/%d\n",
+                         (unsigned long long)lba,
+                         host_byte(result), driver_byte(result));
+               return -EIO;
+       }
+
+       rep_len = get_unaligned_be32(&buf[0]);
+       if (rep_len < 64) {
+               sd_printk(KERN_ERR, sdkp,
+                         "REPORT ZONES report invalid length %u\n",
+                         rep_len);
+               return -EIO;
+       }
+
+       return 0;
+}
+
+int sd_zbc_setup_report_cmnd(struct scsi_cmnd *cmd)
+{
+       struct request *rq = cmd->request;
+       struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+       sector_t lba, sector = blk_rq_pos(rq);
+       unsigned int nr_bytes = blk_rq_bytes(rq);
+       int ret;
+
+       WARN_ON(nr_bytes == 0);
+
+       if (!sd_is_zoned(sdkp))
+               /* Not a zoned device */
+               return BLKPREP_KILL;
+
+       ret = scsi_init_io(cmd);
+       if (ret != BLKPREP_OK)
+               return ret;
+
+       cmd->cmd_len = 16;
+       memset(cmd->cmnd, 0, cmd->cmd_len);
+       cmd->cmnd[0] = ZBC_IN;
+       cmd->cmnd[1] = ZI_REPORT_ZONES;
+       lba = sectors_to_logical(sdkp->device, sector);
+       put_unaligned_be64(lba, &cmd->cmnd[2]);
+       put_unaligned_be32(nr_bytes, &cmd->cmnd[10]);
+       /* Do partial report for speeding things up */
+       cmd->cmnd[14] = ZBC_REPORT_ZONE_PARTIAL;
+
+       cmd->sc_data_direction = DMA_FROM_DEVICE;
+       cmd->sdb.length = nr_bytes;
+       cmd->transfersize = sdkp->device->sector_size;
+       cmd->allowed = 0;
+
+       /*
+        * Report may return less bytes than requested. Make sure
+        * to report completion on the entire initial request.
+        */
+       rq->__data_len = nr_bytes;
+
+       return BLKPREP_OK;
+}
+
+static void sd_zbc_report_zones_complete(struct scsi_cmnd *scmd,
+                                        unsigned int good_bytes)
+{
+       struct request *rq = scmd->request;
+       struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+       struct sg_mapping_iter miter;
+       struct blk_zone_report_hdr hdr;
+       struct blk_zone zone;
+       unsigned int offset, bytes = 0;
+       unsigned long flags;
+       u8 *buf;
+
+       if (good_bytes < 64)
+               return;
+
+       memset(&hdr, 0, sizeof(struct blk_zone_report_hdr));
+
+       sg_miter_start(&miter, scsi_sglist(scmd), scsi_sg_count(scmd),
+                      SG_MITER_TO_SG | SG_MITER_ATOMIC);
+
+       local_irq_save(flags);
+       while (sg_miter_next(&miter) && bytes < good_bytes) {
+
+               buf = miter.addr;
+               offset = 0;
+
+               if (bytes == 0) {
+                       /* Set the report header */
+                       hdr.nr_zones = min_t(unsigned int,
+                                        (good_bytes - 64) / 64,
+                                        get_unaligned_be32(&buf[0]) / 64);
+                       memcpy(buf, &hdr, sizeof(struct blk_zone_report_hdr));
+                       offset += 64;
+                       bytes += 64;
+               }
+
+               /* Parse zone descriptors */
+               while (offset < miter.length && hdr.nr_zones) {
+                       WARN_ON(offset > miter.length);
+                       buf = miter.addr + offset;
+                       sd_zbc_parse_report(sdkp, buf, &zone);
+                       memcpy(buf, &zone, sizeof(struct blk_zone));
+                       offset += 64;
+                       bytes += 64;
+                       hdr.nr_zones--;
+               }
+
+               if (!hdr.nr_zones)
+                       break;
+
+       }
+       sg_miter_stop(&miter);
+       local_irq_restore(flags);
+}
+
+static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
+{
+       return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
+}
+
+static inline unsigned int sd_zbc_zone_no(struct scsi_disk *sdkp,
+                                         sector_t sector)
+{
+       return sectors_to_logical(sdkp->device, sector) >> sdkp->zone_shift;
+}
+
+int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
+{
+       struct request *rq = cmd->request;
+       struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+       sector_t sector = blk_rq_pos(rq);
+       sector_t block = sectors_to_logical(sdkp->device, sector);
+
+       if (!sd_is_zoned(sdkp))
+               /* Not a zoned device */
+               return BLKPREP_KILL;
+
+       if (sdkp->device->changed)
+               return BLKPREP_KILL;
+
+       if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
+               /* Unaligned request */
+               return BLKPREP_KILL;
+
+       /* Do not allow concurrent reset and writes */
+       if (!test_and_set_bit(sd_zbc_zone_no(sdkp, sector),
+                             sdkp->zones_wlock))
+               return BLKPREP_DEFER;
+
+       cmd->cmd_len = 16;
+       memset(cmd->cmnd, 0, cmd->cmd_len);
+       cmd->cmnd[0] = ZBC_OUT;
+       cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
+       put_unaligned_be64(block, &cmd->cmnd[2]);
+
+       rq->timeout = SD_TIMEOUT;
+       cmd->sc_data_direction = DMA_NONE;
+       cmd->transfersize = 0;
+       cmd->allowed = 0;
+
+       return BLKPREP_OK;
+}
+
+int sd_zbc_setup_read_write(struct scsi_cmnd *cmd)
+{
+        struct request *rq = cmd->request;
+
+       /*
+        * Note: alignment of the read/write on logical blocks
+        * is done after this function returns in sd_setup_read_write.
+        */
+
+       /*
+        * Do not issue more than one write at a time per
+        * zone. This solves write ordering problems due to
+        * the unlocking of the request queue in the dispatch
+        * path in the non scsi-mq case. For scsi-mq, this
+        * also avoids potential write reordering when multiple
+        * threads running on different CPUs write to the same
+        * zone (with a synchronized sequential pattern).
+        */
+       if (req_op(rq) == REQ_OP_WRITE ||
+           req_op(rq) == REQ_OP_WRITE_SAME) {
+               struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+               sector_t sector = blk_rq_pos(rq);
+               sector_t zone_sectors = sd_zbc_zone_sectors(sdkp);
+               sector_t zone_ofst = sector & (zone_sectors - 1);
+
+               /* Do not allow zone boundaries crossing */
+               if (zone_ofst + blk_rq_sectors(rq) > zone_sectors)
+                       return BLKPREP_KILL;
+
+               if (!test_and_set_bit(sd_zbc_zone_no(sdkp, sector),
+                                     sdkp->zones_wlock))
+                       return BLKPREP_DEFER;
+       }
+
+       return BLKPREP_OK;
+}
+
+void sd_zbc_complete(struct scsi_cmnd *cmd,
+                    unsigned int good_bytes,
+                    struct scsi_sense_hdr *sshdr)
+{
+       int result = cmd->result;
+       struct request *rq = cmd->request;
+       struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
+
+       switch (req_op(rq)) {
+       case REQ_OP_WRITE:
+       case REQ_OP_WRITE_SAME:
+
+               if (result &&
+                   sshdr->sense_key == ILLEGAL_REQUEST &&
+                   sshdr->asc == 0x21)
+                       /*
+                        * It is unlikely that retrying write requests failed
+                        * with any kind of alignement error will result in
+                        * success. So don't.
+                        */
+                       cmd->allowed = 0;
+
+               /* Fallthru */
+
+       case REQ_OP_ZONE_RESET:
+
+               /* Unlock the zone */
+               clear_bit_unlock(sd_zbc_zone_no(sdkp, blk_rq_pos(rq)),
+                                sdkp->zones_wlock);
+               smp_mb__after_atomic();
+
+               if (result &&
+                   sshdr->sense_key == ILLEGAL_REQUEST &&
+                   sshdr->asc == 0x24)
+                       /*
+                        * INVALID FIELD IN CDB error: Reset of a conventional
+                        * zone was attempted. Nothing to worry about,
+                        * so be quiet about the error.
+                        */
+                       rq->cmd_flags |= REQ_QUIET;
+
+               break;
+
+       case REQ_OP_ZONE_REPORT:
+
+               if (!result)
+                       sd_zbc_report_zones_complete(cmd, good_bytes);
+               break;
+
+       }
+}
+
+/**
+ * Read zoned block device characteristics (VPD page B6).
+ */
+static int sd_zbc_read_zoned_characteristics(struct scsi_disk *sdkp,
+                                            unsigned char *buf)
+{
+
+       if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
+               sd_printk(KERN_NOTICE, sdkp,
+                         "Unconstrained-read check failed\n");
+               return -ENODEV;
+       }
+
+       if (sdkp->device->type != TYPE_ZBC) {
+               /* Host-aware */
+               sdkp->urswrz = 1;
+               sdkp->zones_optimal_open = get_unaligned_be64(&buf[8]);
+               sdkp->zones_optimal_nonseq = get_unaligned_be64(&buf[12]);
+               sdkp->zones_max_open = 0;
+       } else {
+               /* Host-managed */
+               sdkp->urswrz = buf[4] & 1;
+               sdkp->zones_optimal_open = 0;
+               sdkp->zones_optimal_nonseq = 0;
+               sdkp->zones_max_open = get_unaligned_be64(&buf[16]);
+       }
+
+       return 0;
+}
+
+/**
+ * Check reported capacity.
+ */
+static int sd_zbc_check_capacity(struct scsi_disk *sdkp,
+                                unsigned char *buf)
+{
+       sector_t lba;
+       int ret;
+
+       if (sdkp->rc_basis != 0)
+               return 0;
+
+       /* Do a report zone to get the maximum LBA to check capacity */
+       ret = sd_zbc_report_zones(sdkp, buf, SD_BUF_SIZE, 0);
+       if (ret)
+               return ret;
+
+       /* The max_lba field is the capacity of this device */
+       lba = get_unaligned_be64(&buf[8]);
+       if (lba + 1 == sdkp->capacity)
+               return 0;
+
+       if (sdkp->first_scan)
+               sd_printk(KERN_WARNING, sdkp,
+                         "Changing capacity from %zu to max LBA+1 %llu\n",
+                         sdkp->capacity,
+                         (unsigned long long)lba + 1);
+       sdkp->capacity = lba + 1;
+
+       return 0;
+}
+
+#define SD_ZBC_BUF_SIZE 131072
+
+static int sd_zbc_check_zone_size(struct scsi_disk *sdkp)
+{
+       u64 zone_blocks;
+       sector_t block = 0;
+       unsigned char *buf;
+       unsigned char *rec;
+       unsigned int buf_len;
+       unsigned int list_length;
+       int ret;
+       u8 same;
+
+       sdkp->zone_blocks = 0;
+
+       /* Get a buffer */
+       buf = kmalloc(SD_ZBC_BUF_SIZE, GFP_KERNEL);
+       if (!buf)
+               return -ENOMEM;
+
+       /* Do a report zone to get the same field */
+       ret = sd_zbc_report_zones(sdkp, buf, SD_ZBC_BUF_SIZE, 0);
+       if (ret)
+               goto out;
+
+       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 */
+               list_length = get_unaligned_be32(&buf[0]) + 64;
+               rec = buf + 64;
+               if (list_length < SD_ZBC_BUF_SIZE)
+                       buf_len = list_length;
+               else
+                       buf_len = SD_ZBC_BUF_SIZE;
+
+               /* Parse zone descriptors */
+               while (rec < buf + buf_len) {
+                       zone_blocks = get_unaligned_be64(&rec[8]);
+                       if (sdkp->zone_blocks == 0) {
+                               sdkp->zone_blocks = zone_blocks;
+                       } else if (zone_blocks != sdkp->zone_blocks &&
+                                  (block + zone_blocks < sdkp->capacity
+                                   || zone_blocks > sdkp->zone_blocks)) {
+                               zone_blocks = 0;
+                               goto out;
+                       }
+                       block += zone_blocks;
+                       rec += 64;
+               }
+
+               if (block < sdkp->capacity) {
+                       ret = sd_zbc_report_zones(sdkp, buf,
+                                                 SD_ZBC_BUF_SIZE, block);
+                       if (ret)
+                               return ret;
+               }
+
+       } while (block < sdkp->capacity);
+
+       zone_blocks = sdkp->zone_blocks;
+
+out:
+       kfree(buf);
+
+       if (!zone_blocks) {
+               if (sdkp->first_scan)
+                       sd_printk(KERN_NOTICE, sdkp,
+                                 "Devices with non constant zone "
+                                 "size are not supported\n");
+               return -ENODEV;
+       }
+
+       if (!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");
+               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");
+               return -ENODEV;
+       }
+
+       sdkp->zone_blocks = zone_blocks;
+
+       return 0;
+}
+
+static int sd_zbc_setup(struct scsi_disk *sdkp)
+{
+
+       /* chunk_sectors indicates the zone size */
+       blk_queue_chunk_sectors(sdkp->disk->queue,
+                       logical_to_sectors(sdkp->device, sdkp->zone_blocks));
+       sdkp->zone_shift = ilog2(sdkp->zone_blocks);
+       sdkp->nr_zones = sdkp->capacity >> sdkp->zone_shift;
+       if (sdkp->capacity & (sdkp->zone_blocks - 1))
+               sdkp->nr_zones++;
+
+       if (!sdkp->zones_wlock) {
+               sdkp->zones_wlock = kzalloc(BITS_TO_LONGS(sdkp->nr_zones),
+                                           GFP_KERNEL);
+               if (!sdkp->zones_wlock)
+                       return -ENOMEM;
+       }
+
+       return 0;
+}
+
+int sd_zbc_read_zones(struct scsi_disk *sdkp,
+                     unsigned char *buf)
+{
+       sector_t capacity;
+       int ret = 0;
+
+       if (!sd_is_zoned(sdkp))
+               /*
+                * Device managed or normal SCSI disk,
+                * no special handling required
+                */
+               return 0;
+
+
+       /* Get zoned block device characteristics */
+       ret = sd_zbc_read_zoned_characteristics(sdkp, buf);
+       if (ret)
+               goto err;
+
+       /*
+        * Check for unconstrained reads: host-managed devices with
+        * constrained reads (drives failing read after write pointer)
+        * are not supported.
+        */
+       if (!sdkp->urswrz) {
+               if (sdkp->first_scan)
+                       sd_printk(KERN_NOTICE, sdkp,
+                         "constrained reads devices are not supported\n");
+               ret = -ENODEV;
+               goto err;
+       }
+
+       /* Check capacity */
+       ret = sd_zbc_check_capacity(sdkp, buf);
+       if (ret)
+               goto err;
+       capacity = logical_to_sectors(sdkp->device, sdkp->capacity);
+
+       /*
+        * 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_zone_size(sdkp);
+       if (ret)
+               goto err;
+
+       /* The drive satisfies the kernel restrictions: set it up */
+       ret = sd_zbc_setup(sdkp);
+       if (ret)
+               goto err;
+
+       return 0;
+
+err:
+       sdkp->capacity = 0;
+
+       return ret;
+}
+
+void sd_zbc_remove(struct scsi_disk *sdkp)
+{
+       kfree(sdkp->zones_wlock);
+       sdkp->zones_wlock = NULL;
+}
+
+void sd_zbc_print_zones(struct scsi_disk *sdkp)
+{
+       if (!sd_is_zoned(sdkp) || !sdkp->capacity)
+               return;
+
+       if (sdkp->capacity & (sdkp->zone_blocks - 1))
+               sd_printk(KERN_NOTICE, sdkp,
+                         "%u zones of %u logical blocks + 1 runt zone\n",
+                         sdkp->nr_zones - 1,
+                         sdkp->zone_blocks);
+       else
+               sd_printk(KERN_NOTICE, sdkp,
+                         "%u zones of %u logical blocks\n",
+                         sdkp->nr_zones,
+                         sdkp->zone_blocks);
+}
diff --git a/include/scsi/scsi_proto.h b/include/scsi/scsi_proto.h
index d1defd1..6ba66e0 100644
--- a/include/scsi/scsi_proto.h
+++ b/include/scsi/scsi_proto.h
@@ -299,4 +299,21 @@ struct scsi_lun {
 #define SCSI_ACCESS_STATE_MASK        0x0f
 #define SCSI_ACCESS_STATE_PREFERRED   0x80
 
+/* Reporting options for REPORT ZONES */
+enum zbc_zone_reporting_options {
+       ZBC_ZONE_REPORTING_OPTION_ALL = 0,
+       ZBC_ZONE_REPORTING_OPTION_EMPTY,
+       ZBC_ZONE_REPORTING_OPTION_IMPLICIT_OPEN,
+       ZBC_ZONE_REPORTING_OPTION_EXPLICIT_OPEN,
+       ZBC_ZONE_REPORTING_OPTION_CLOSED,
+       ZBC_ZONE_REPORTING_OPTION_FULL,
+       ZBC_ZONE_REPORTING_OPTION_READONLY,
+       ZBC_ZONE_REPORTING_OPTION_OFFLINE,
+       ZBC_ZONE_REPORTING_OPTION_NEED_RESET_WP = 0x10,
+       ZBC_ZONE_REPORTING_OPTION_NON_SEQWRITE,
+       ZBC_ZONE_REPORTING_OPTION_NON_WP = 0x3f,
+};
+
+#define ZBC_REPORT_ZONE_PARTIAL 0x80
+
 #endif /* _SCSI_PROTO_H_ */
-- 
2.7.4

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