root/drivers/scsi/sd_zbc.c

DEFINITIONS

1. sd_zbc_parse_report
2. sd_zbc_do_report_zones
3. sd_zbc_alloc_report_buffer
4. sd_zbc_report_zones
5. sd_zbc_zone_sectors
6. sd_zbc_setup_reset_cmnd
7. sd_zbc_complete
8. sd_zbc_check_zoned_characteristics
9. sd_zbc_check_zones
10. sd_zbc_read_zones
11. sd_zbc_print_zones

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * SCSI Zoned Block commands
   4  *
   5  * Copyright (C) 2014-2015 SUSE Linux GmbH
   6  * Written by: Hannes Reinecke <hare@suse.de>
   7  * Modified by: Damien Le Moal <damien.lemoal@hgst.com>
   8  * Modified by: Shaun Tancheff <shaun.tancheff@seagate.com>
   9  */
  10 
  11 #include <linux/blkdev.h>
  12 #include <linux/vmalloc.h>
  13 #include <linux/sched/mm.h>
  14 
  15 #include <asm/unaligned.h>
  16 
  17 #include <scsi/scsi.h>
  18 #include <scsi/scsi_cmnd.h>
  19 
  20 #include "sd.h"
  21 
  22 /**
  23  * sd_zbc_parse_report - Convert a zone descriptor to a struct blk_zone,
  24  * @sdkp: The disk the report originated from
  25  * @buf: Address of the report zone descriptor
  26  * @zone: the destination zone structure
  27  *
  28  * All LBA sized values are converted to 512B sectors unit.
  29  */
  30 static void sd_zbc_parse_report(struct scsi_disk *sdkp, u8 *buf,
  31                                 struct blk_zone *zone)
  32 {
  33         struct scsi_device *sdp = sdkp->device;
  34 
  35         memset(zone, 0, sizeof(struct blk_zone));
  36 
  37         zone->type = buf[0] & 0x0f;
  38         zone->cond = (buf[1] >> 4) & 0xf;
  39         if (buf[1] & 0x01)
  40                 zone->reset = 1;
  41         if (buf[1] & 0x02)
  42                 zone->non_seq = 1;
  43 
  44         zone->len = logical_to_sectors(sdp, get_unaligned_be64(&buf[8]));
  45         zone->start = logical_to_sectors(sdp, get_unaligned_be64(&buf[16]));
  46         zone->wp = logical_to_sectors(sdp, get_unaligned_be64(&buf[24]));
  47         if (zone->type != ZBC_ZONE_TYPE_CONV &&
  48             zone->cond == ZBC_ZONE_COND_FULL)
  49                 zone->wp = zone->start + zone->len;
  50 }
  51 
  52 /**
  53  * sd_zbc_do_report_zones - Issue a REPORT ZONES scsi command.
  54  * @sdkp: The target disk
  55  * @buf: vmalloc-ed buffer to use for the reply
  56  * @buflen: the buffer size
  57  * @lba: Start LBA of the report
  58  * @partial: Do partial report
  59  *
  60  * For internal use during device validation.
  61  * Using partial=true can significantly speed up execution of a report zones
  62  * command because the disk does not have to count all possible report matching
  63  * zones and will only report the count of zones fitting in the command reply
  64  * buffer.
  65  */
  66 static int sd_zbc_do_report_zones(struct scsi_disk *sdkp, unsigned char *buf,
  67                                   unsigned int buflen, sector_t lba,
  68                                   bool partial)
  69 {
  70         struct scsi_device *sdp = sdkp->device;
  71         const int timeout = sdp->request_queue->rq_timeout;
  72         struct scsi_sense_hdr sshdr;
  73         unsigned char cmd[16];
  74         unsigned int rep_len;
  75         int result;
  76 
  77         memset(cmd, 0, 16);
  78         cmd[0] = ZBC_IN;
  79         cmd[1] = ZI_REPORT_ZONES;
  80         put_unaligned_be64(lba, &cmd[2]);
  81         put_unaligned_be32(buflen, &cmd[10]);
  82         if (partial)
  83                 cmd[14] = ZBC_REPORT_ZONE_PARTIAL;
  84 
  85         result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,
  86                                   buf, buflen, &sshdr,
  87                                   timeout, SD_MAX_RETRIES, NULL);
  88         if (result) {
  89                 sd_printk(KERN_ERR, sdkp,
  90                           "REPORT ZONES lba %llu failed with %d/%d\n",
  91                           (unsigned long long)lba,
  92                           host_byte(result), driver_byte(result));
  93                 return -EIO;
  94         }
  95 
  96         rep_len = get_unaligned_be32(&buf[0]);
  97         if (rep_len < 64) {
  98                 sd_printk(KERN_ERR, sdkp,
  99                           "REPORT ZONES report invalid length %u\n",
 100                           rep_len);
 101                 return -EIO;
 102         }
 103 
 104         return 0;
 105 }
 106 
 107 /*
 108  * Maximum number of zones to get with one report zones command.
 109  */
 110 #define SD_ZBC_REPORT_MAX_ZONES         8192U
 111 
 112 /**
 113  * Allocate a buffer for report zones reply.
 114  * @sdkp: The target disk
 115  * @nr_zones: Maximum number of zones to report
 116  * @buflen: Size of the buffer allocated
 117  *
 118  * Try to allocate a reply buffer for the number of requested zones.
 119  * The size of the buffer allocated may be smaller than requested to
 120  * satify the device constraint (max_hw_sectors, max_segments, etc).
 121  *
 122  * Return the address of the allocated buffer and update @buflen with
 123  * the size of the allocated buffer.
 124  */
 125 static void *sd_zbc_alloc_report_buffer(struct scsi_disk *sdkp,
 126                                         unsigned int nr_zones, size_t *buflen)
 127 {
 128         struct request_queue *q = sdkp->disk->queue;
 129         size_t bufsize;
 130         void *buf;
 131 
 132         /*
 133          * Report zone buffer size should be at most 64B times the number of
 134          * zones requested plus the 64B reply header, but should be at least
 135          * SECTOR_SIZE for ATA devices.
 136          * Make sure that this size does not exceed the hardware capabilities.
 137          * Furthermore, since the report zone command cannot be split, make
 138          * sure that the allocated buffer can always be mapped by limiting the
 139          * number of pages allocated to the HBA max segments limit.
 140          */
 141         nr_zones = min(nr_zones, SD_ZBC_REPORT_MAX_ZONES);
 142         bufsize = roundup((nr_zones + 1) * 64, 512);
 143         bufsize = min_t(size_t, bufsize,
 144                         queue_max_hw_sectors(q) << SECTOR_SHIFT);
 145         bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT);
 146 
 147         buf = vzalloc(bufsize);
 148         if (buf)
 149                 *buflen = bufsize;
 150 
 151         return buf;
 152 }
 153 
 154 /**
 155  * sd_zbc_report_zones - Disk report zones operation.
 156  * @disk: The target disk
 157  * @sector: Start 512B sector of the report
 158  * @zones: Array of zone descriptors
 159  * @nr_zones: Number of descriptors in the array
 160  *
 161  * Execute a report zones command on the target disk.
 162  */
 163 int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
 164                         struct blk_zone *zones, unsigned int *nr_zones)
 165 {
 166         struct scsi_disk *sdkp = scsi_disk(disk);
 167         unsigned int i, nrz = *nr_zones;
 168         unsigned char *buf;
 169         size_t buflen = 0, offset = 0;
 170         int ret = 0;
 171 
 172         if (!sd_is_zoned(sdkp))
 173                 /* Not a zoned device */
 174                 return -EOPNOTSUPP;
 175 
 176         buf = sd_zbc_alloc_report_buffer(sdkp, nrz, &buflen);
 177         if (!buf)
 178                 return -ENOMEM;
 179 
 180         ret = sd_zbc_do_report_zones(sdkp, buf, buflen,
 181                         sectors_to_logical(sdkp->device, sector), true);
 182         if (ret)
 183                 goto out;
 184 
 185         nrz = min(nrz, get_unaligned_be32(&buf[0]) / 64);
 186         for (i = 0; i < nrz; i++) {
 187                 offset += 64;
 188                 sd_zbc_parse_report(sdkp, buf + offset, zones);
 189                 zones++;
 190         }
 191 
 192         *nr_zones = nrz;
 193 
 194 out:
 195         kvfree(buf);
 196 
 197         return ret;
 198 }
 199 
 200 /**
 201  * sd_zbc_zone_sectors - Get the device zone size in number of 512B sectors.
 202  * @sdkp: The target disk
 203  */
 204 static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
 205 {
 206         return logical_to_sectors(sdkp->device, sdkp->zone_blocks);
 207 }
 208 
 209 /**
 210  * sd_zbc_setup_reset_cmnd - Prepare a RESET WRITE POINTER scsi command.
 211  * @cmd: the command to setup
 212  * @all: Reset all zones control.
 213  *
 214  * Called from sd_init_command() for a REQ_OP_ZONE_RESET request.
 215  */
 216 blk_status_t sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd, bool all)
 217 {
 218         struct request *rq = cmd->request;
 219         struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
 220         sector_t sector = blk_rq_pos(rq);
 221         sector_t block = sectors_to_logical(sdkp->device, sector);
 222 
 223         if (!sd_is_zoned(sdkp))
 224                 /* Not a zoned device */
 225                 return BLK_STS_IOERR;
 226 
 227         if (sdkp->device->changed)
 228                 return BLK_STS_IOERR;
 229 
 230         if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
 231                 /* Unaligned request */
 232                 return BLK_STS_IOERR;
 233 
 234         cmd->cmd_len = 16;
 235         memset(cmd->cmnd, 0, cmd->cmd_len);
 236         cmd->cmnd[0] = ZBC_OUT;
 237         cmd->cmnd[1] = ZO_RESET_WRITE_POINTER;
 238         if (all)
 239                 cmd->cmnd[14] = 0x1;
 240         else
 241                 put_unaligned_be64(block, &cmd->cmnd[2]);
 242 
 243         rq->timeout = SD_TIMEOUT;
 244         cmd->sc_data_direction = DMA_NONE;
 245         cmd->transfersize = 0;
 246         cmd->allowed = 0;
 247 
 248         return BLK_STS_OK;
 249 }
 250 
 251 /**
 252  * sd_zbc_complete - ZBC command post processing.
 253  * @cmd: Completed command
 254  * @good_bytes: Command reply bytes
 255  * @sshdr: command sense header
 256  *
 257  * Called from sd_done(). Process report zones reply and handle reset zone
 258  * and write commands errors.
 259  */
 260 void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
 261                      struct scsi_sense_hdr *sshdr)
 262 {
 263         int result = cmd->result;
 264         struct request *rq = cmd->request;
 265 
 266         if (req_op(rq) == REQ_OP_ZONE_RESET &&
 267             result &&
 268             sshdr->sense_key == ILLEGAL_REQUEST &&
 269             sshdr->asc == 0x24) {
 270                 /*
 271                  * INVALID FIELD IN CDB error: reset of a conventional
 272                  * zone was attempted. Nothing to worry about, so be
 273                  * quiet about the error.
 274                  */
 275                 rq->rq_flags |= RQF_QUIET;
 276         }
 277 }
 278 
 279 /**
 280  * sd_zbc_check_zoned_characteristics - Check zoned block device characteristics
 281  * @sdkp: Target disk
 282  * @buf: Buffer where to store the VPD page data
 283  *
 284  * Read VPD page B6, get information and check that reads are unconstrained.
 285  */
 286 static int sd_zbc_check_zoned_characteristics(struct scsi_disk *sdkp,
 287                                               unsigned char *buf)
 288 {
 289 
 290         if (scsi_get_vpd_page(sdkp->device, 0xb6, buf, 64)) {
 291                 sd_printk(KERN_NOTICE, sdkp,
 292                           "Read zoned characteristics VPD page failed\n");
 293                 return -ENODEV;
 294         }
 295 
 296         if (sdkp->device->type != TYPE_ZBC) {
 297                 /* Host-aware */
 298                 sdkp->urswrz = 1;
 299                 sdkp->zones_optimal_open = get_unaligned_be32(&buf[8]);
 300                 sdkp->zones_optimal_nonseq = get_unaligned_be32(&buf[12]);
 301                 sdkp->zones_max_open = 0;
 302         } else {
 303                 /* Host-managed */
 304                 sdkp->urswrz = buf[4] & 1;
 305                 sdkp->zones_optimal_open = 0;
 306                 sdkp->zones_optimal_nonseq = 0;
 307                 sdkp->zones_max_open = get_unaligned_be32(&buf[16]);
 308         }
 309 
 310         /*
 311          * Check for unconstrained reads: host-managed devices with
 312          * constrained reads (drives failing read after write pointer)
 313          * are not supported.
 314          */
 315         if (!sdkp->urswrz) {
 316                 if (sdkp->first_scan)
 317                         sd_printk(KERN_NOTICE, sdkp,
 318                           "constrained reads devices are not supported\n");
 319                 return -ENODEV;
 320         }
 321 
 322         return 0;
 323 }
 324 
 325 /**
 326  * sd_zbc_check_zones - Check the device capacity and zone sizes
 327  * @sdkp: Target disk
 328  *
 329  * Check that the device capacity as reported by READ CAPACITY matches the
 330  * max_lba value (plus one)of the report zones command reply. Also check that
 331  * all zones of the device have an equal size, only allowing the last zone of
 332  * the disk to have a smaller size (runt zone). The zone size must also be a
 333  * power of two.
 334  *
 335  * Returns the zone size in number of blocks upon success or an error code
 336  * upon failure.
 337  */
 338 static int sd_zbc_check_zones(struct scsi_disk *sdkp, u32 *zblocks)
 339 {
 340         size_t bufsize, buflen;
 341         unsigned int noio_flag;
 342         u64 zone_blocks = 0;
 343         sector_t max_lba, block = 0;
 344         unsigned char *buf;
 345         unsigned char *rec;
 346         int ret;
 347         u8 same;
 348 
 349         /* Do all memory allocations as if GFP_NOIO was specified */
 350         noio_flag = memalloc_noio_save();
 351 
 352         /* Get a buffer */
 353         buf = sd_zbc_alloc_report_buffer(sdkp, SD_ZBC_REPORT_MAX_ZONES,
 354                                          &bufsize);
 355         if (!buf) {
 356                 ret = -ENOMEM;
 357                 goto out;
 358         }
 359 
 360         /* Do a report zone to get max_lba and the same field */
 361         ret = sd_zbc_do_report_zones(sdkp, buf, bufsize, 0, false);
 362         if (ret)
 363                 goto out_free;
 364 
 365         if (sdkp->rc_basis == 0) {
 366                 /* The max_lba field is the capacity of this device */
 367                 max_lba = get_unaligned_be64(&buf[8]);
 368                 if (sdkp->capacity != max_lba + 1) {
 369                         if (sdkp->first_scan)
 370                                 sd_printk(KERN_WARNING, sdkp,
 371                                         "Changing capacity from %llu to max LBA+1 %llu\n",
 372                                         (unsigned long long)sdkp->capacity,
 373                                         (unsigned long long)max_lba + 1);
 374                         sdkp->capacity = max_lba + 1;
 375                 }
 376         }
 377 
 378         /*
 379          * Check same field: for any value other than 0, we know that all zones
 380          * have the same size.
 381          */
 382         same = buf[4] & 0x0f;
 383         if (same > 0) {
 384                 rec = &buf[64];
 385                 zone_blocks = get_unaligned_be64(&rec[8]);
 386                 goto out;
 387         }
 388 
 389         /*
 390          * Check the size of all zones: all zones must be of
 391          * equal size, except the last zone which can be smaller
 392          * than other zones.
 393          */
 394         do {
 395 
 396                 /* Parse REPORT ZONES header */
 397                 buflen = min_t(size_t, get_unaligned_be32(&buf[0]) + 64,
 398                                bufsize);
 399                 rec = buf + 64;
 400 
 401                 /* Parse zone descriptors */
 402                 while (rec < buf + buflen) {
 403                         u64 this_zone_blocks = get_unaligned_be64(&rec[8]);
 404 
 405                         if (zone_blocks == 0) {
 406                                 zone_blocks = this_zone_blocks;
 407                         } else if (this_zone_blocks != zone_blocks &&
 408                                    (block + this_zone_blocks < sdkp->capacity
 409                                     || this_zone_blocks > zone_blocks)) {
 410                                 zone_blocks = 0;
 411                                 goto out;
 412                         }
 413                         block += this_zone_blocks;
 414                         rec += 64;
 415                 }
 416 
 417                 if (block < sdkp->capacity) {
 418                         ret = sd_zbc_do_report_zones(sdkp, buf, bufsize, block,
 419                                                      true);
 420                         if (ret)
 421                                 goto out_free;
 422                 }
 423 
 424         } while (block < sdkp->capacity);
 425 
 426 out:
 427         if (!zone_blocks) {
 428                 if (sdkp->first_scan)
 429                         sd_printk(KERN_NOTICE, sdkp,
 430                                   "Devices with non constant zone "
 431                                   "size are not supported\n");
 432                 ret = -ENODEV;
 433         } else if (!is_power_of_2(zone_blocks)) {
 434                 if (sdkp->first_scan)
 435                         sd_printk(KERN_NOTICE, sdkp,
 436                                   "Devices with non power of 2 zone "
 437                                   "size are not supported\n");
 438                 ret = -ENODEV;
 439         } else if (logical_to_sectors(sdkp->device, zone_blocks) > UINT_MAX) {
 440                 if (sdkp->first_scan)
 441                         sd_printk(KERN_NOTICE, sdkp,
 442                                   "Zone size too large\n");
 443                 ret = -EFBIG;
 444         } else {
 445                 *zblocks = zone_blocks;
 446                 ret = 0;
 447         }
 448 
 449 out_free:
 450         memalloc_noio_restore(noio_flag);
 451         kvfree(buf);
 452 
 453         return ret;
 454 }
 455 
 456 int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf)
 457 {
 458         struct gendisk *disk = sdkp->disk;
 459         unsigned int nr_zones;
 460         u32 zone_blocks = 0;
 461         int ret;
 462 
 463         if (!sd_is_zoned(sdkp))
 464                 /*
 465                  * Device managed or normal SCSI disk,
 466                  * no special handling required
 467                  */
 468                 return 0;
 469 
 470         /* Check zoned block device characteristics (unconstrained reads) */
 471         ret = sd_zbc_check_zoned_characteristics(sdkp, buf);
 472         if (ret)
 473                 goto err;
 474 
 475         /*
 476          * Check zone size: only devices with a constant zone size (except
 477          * an eventual last runt zone) that is a power of 2 are supported.
 478          */
 479         ret = sd_zbc_check_zones(sdkp, &zone_blocks);
 480         if (ret != 0)
 481                 goto err;
 482 
 483         /* The drive satisfies the kernel restrictions: set it up */
 484         blk_queue_chunk_sectors(sdkp->disk->queue,
 485                         logical_to_sectors(sdkp->device, zone_blocks));
 486         blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue);
 487         blk_queue_required_elevator_features(sdkp->disk->queue,
 488                                              ELEVATOR_F_ZBD_SEQ_WRITE);
 489         nr_zones = round_up(sdkp->capacity, zone_blocks) >> ilog2(zone_blocks);
 490 
 491         /* READ16/WRITE16 is mandatory for ZBC disks */
 492         sdkp->device->use_16_for_rw = 1;
 493         sdkp->device->use_10_for_rw = 0;
 494 
 495         /*
 496          * Revalidate the disk zone bitmaps once the block device capacity is
 497          * set on the second revalidate execution during disk scan and if
 498          * something changed when executing a normal revalidate.
 499          */
 500         if (sdkp->first_scan) {
 501                 sdkp->zone_blocks = zone_blocks;
 502                 sdkp->nr_zones = nr_zones;
 503                 return 0;
 504         }
 505 
 506         if (sdkp->zone_blocks != zone_blocks ||
 507             sdkp->nr_zones != nr_zones ||
 508             disk->queue->nr_zones != nr_zones) {
 509                 ret = blk_revalidate_disk_zones(disk);
 510                 if (ret != 0)
 511                         goto err;
 512                 sdkp->zone_blocks = zone_blocks;
 513                 sdkp->nr_zones = nr_zones;
 514         }
 515 
 516         return 0;
 517 
 518 err:
 519         sdkp->capacity = 0;
 520 
 521         return ret;
 522 }
 523 
 524 void sd_zbc_print_zones(struct scsi_disk *sdkp)
 525 {
 526         if (!sd_is_zoned(sdkp) || !sdkp->capacity)
 527                 return;
 528 
 529         if (sdkp->capacity & (sdkp->zone_blocks - 1))
 530                 sd_printk(KERN_NOTICE, sdkp,
 531                           "%u zones of %u logical blocks + 1 runt zone\n",
 532                           sdkp->nr_zones - 1,
 533                           sdkp->zone_blocks);
 534         else
 535                 sd_printk(KERN_NOTICE, sdkp,
 536                           "%u zones of %u logical blocks\n",
 537                           sdkp->nr_zones,
 538                           sdkp->zone_blocks);
 539 }