On Wed, Sep 28, 2016 at 3:45 AM, Damien Le Moal <damien.lem...@hgst.com> wrote:
> 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>]
> Signed-off-by: Damien Le Moal <damien.lem...@hgst.com>
> ---
>  drivers/scsi/Makefile     |   1 +
>  drivers/scsi/sd.c         | 143 ++++++++---
>  drivers/scsi/sd.h         |  70 ++++++
>  drivers/scsi/sd_zbc.c     | 624 
> ++++++++++++++++++++++++++++++++++++++++++++++
>  include/scsi/scsi_proto.h |  17 ++
>  5 files changed, 822 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..4d63260 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 +850,13 @@ 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)) {
> +               /* sd_zbc_setup_read_write uses block layer sector units */
> +               ret = sd_zbc_setup_read_write(sdkp, rq, sector, nr_sectors);
> +               if (ret != BLKPREP_OK)
> +                       return ret;
> +       }
> +
>         sector >>= ilog2(sdp->sector_size) - 9;
>         nr_sectors >>= ilog2(sdp->sector_size) - 9;
>
> @@ -963,6 +976,13 @@ 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)) {
> +               /* sd_zbc_setup_read_write uses block layer sector units */
> +               ret = sd_zbc_setup_read_write(sdkp, rq, block, this_count);
> +               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 +1169,10 @@ 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 +1804,10 @@ 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 +1815,17 @@ 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 +1886,11 @@ 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 +2025,6 @@ sd_spinup_disk(struct scsi_disk *sdkp)
>         }
>  }
>
> -
>  /*
>   * Determine whether disk supports Data Integrity Field.
>   */
> @@ -2133,6 +2174,9 @@ 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 +2286,6 @@ 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 +2366,44 @@ 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 +2665,7 @@ 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 +2772,7 @@ 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 +2787,21 @@ 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 +2873,7 @@ 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 +2907,11 @@ 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 +3109,16 @@ 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 +3222,8 @@ 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..6bd4226 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 +256,57 @@ 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_disk *sdkp, struct request 
> *rq,
> +                                  sector_t sector, unsigned int nr_sectors);
> +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_disk *sdkp,
> +                                         struct request *rq, sector_t sector,
> +                                         unsigned int num_sectors)
> +{
> +       /* 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..a4da0ed
> --- /dev/null
> +++ b/drivers/scsi/sd_zbc.c
> @@ -0,0 +1,624 @@
> +/*
> + * 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_disk *sdkp, struct request *rq,
> +                           sector_t sector, unsigned int nr_sectors)
> +{
> +       sector_t zone_sectors = sd_zbc_zone_sectors(sdkp);
> +       sector_t zone_ofst = sector & (zone_sectors - 1);
> +
> +       /*
> +        * Note: alignment of the read/write on logical blocks
> +        * is done after this function returns in sd_setup_read_write.
> +        */
> +
> +       /* Do not allow zone boundaries crossing */
> +       if (zone_ofst + nr_sectors > zone_sectors)
> +               return BLKPREP_KILL;
> +
> +       /*
> +        * 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) {
> +               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

Reviewed-by: Shaun Tancheff <shaun.tanch...@seagate.com>
Tested-by: Shaun Tancheff <shaun.tanch...@seagate.com>

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