drivers/target/target_core_sbc.c

   1 /*
   2  * SCSI Block Commands (SBC) parsing and emulation.
   3  *
   4  * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
   5  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
   6  * Copyright (c) 2007-2010 Rising Tide Systems
   7  * Copyright (c) 2008-2010 Linux-iSCSI.org
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/module.h>
  28 #include <linux/ratelimit.h>
  29 #include <asm/unaligned.h>
  30 #include <scsi/scsi.h>
  31
  32 #include <target/target_core_base.h>
  33 #include <target/target_core_backend.h>
  34 #include <target/target_core_fabric.h>
  35
  36 #include "target_core_internal.h"
  37 #include "target_core_ua.h"
  38
  39
  40 static int sbc_emulate_readcapacity(struct se_cmd *cmd)
  41 {
  42         struct se_device *dev = cmd->se_dev;
  43         unsigned char *buf;
  44         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  45         u32 blocks;
  46
  47         if (blocks_long >= 0x00000000ffffffff)
  48                 blocks = 0xffffffff;
  49         else
  50                 blocks = (u32)blocks_long;
  51
  52         buf = transport_kmap_data_sg(cmd);
  53
  54         buf[0] = (blocks >> 24) & 0xff;
  55         buf[1] = (blocks >> 16) & 0xff;
  56         buf[2] = (blocks >> 8) & 0xff;
  57         buf[3] = blocks & 0xff;
  58         buf[4] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
  59         buf[5] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
  60         buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
  61         buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
  62
  63         transport_kunmap_data_sg(cmd);
  64
  65         target_complete_cmd(cmd, GOOD);
  66         return 0;
  67 }
  68
  69 static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  70 {
  71         struct se_device *dev = cmd->se_dev;
  72         unsigned char *buf;
  73         unsigned long long blocks = dev->transport->get_blocks(dev);
  74
  75         buf = transport_kmap_data_sg(cmd);
  76
  77         buf[0] = (blocks >> 56) & 0xff;
  78         buf[1] = (blocks >> 48) & 0xff;
  79         buf[2] = (blocks >> 40) & 0xff;
  80         buf[3] = (blocks >> 32) & 0xff;
  81         buf[4] = (blocks >> 24) & 0xff;
  82         buf[5] = (blocks >> 16) & 0xff;
  83         buf[6] = (blocks >> 8) & 0xff;
  84         buf[7] = blocks & 0xff;
  85         buf[8] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
  86         buf[9] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
  87         buf[10] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
  88         buf[11] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
  89         /*
  90          * Set Thin Provisioning Enable bit following sbc3r22 in section
  91          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
  92          */
  93         if (dev->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws)
  94                 buf[14] = 0x80;
  95
  96         transport_kunmap_data_sg(cmd);
  97
  98         target_complete_cmd(cmd, GOOD);
  99         return 0;
 100 }
 101
 102 /*
 103  * Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
 104  * Note this is not used for TCM/pSCSI passthrough
 105  */
 106 static int sbc_emulate_unmap(struct se_cmd *cmd)
 107 {
 108         struct se_device *dev = cmd->se_dev;
 109         unsigned char *buf, *ptr = NULL;
 110         unsigned char *cdb = &cmd->t_task_cdb[0];
 111         sector_t lba;
 112         unsigned int size = cmd->data_length, range;
 113         int ret = 0, offset;
 114         unsigned short dl, bd_dl;
 115
 116         if (!dev->transport->do_discard) {
 117                 pr_err("UNMAP emulation not supported for: %s\n",
 118                                 dev->transport->name);
 119                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 120                 return -ENOSYS;
 121         }
 122
 123         /* First UNMAP block descriptor starts at 8 byte offset */
 124         offset = 8;
 125         size -= 8;
 126         dl = get_unaligned_be16(&cdb[0]);
 127         bd_dl = get_unaligned_be16(&cdb[2]);
 128
 129         buf = transport_kmap_data_sg(cmd);
 130
 131         ptr = &buf[offset];
 132         pr_debug("UNMAP: Sub: %s Using dl: %hu bd_dl: %hu size: %hu"
 133                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
 134
 135         while (size) {
 136                 lba = get_unaligned_be64(&ptr[0]);
 137                 range = get_unaligned_be32(&ptr[8]);
 138                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
 139                                  (unsigned long long)lba, range);
 140
 141                 ret = dev->transport->do_discard(dev, lba, range);
 142                 if (ret < 0) {
 143                         pr_err("blkdev_issue_discard() failed: %d\n",
 144                                         ret);
 145                         goto err;
 146                 }
 147
 148                 ptr += 16;
 149                 size -= 16;
 150         }
 151
 152 err:
 153         transport_kunmap_data_sg(cmd);
 154         if (!ret)
 155                 target_complete_cmd(cmd, GOOD);
 156         return ret;
 157 }
 158
 159 /*
 160  * Used for TCM/IBLOCK and TCM/FILEIO for block/blk-lib.c level discard support.
 161  * Note this is not used for TCM/pSCSI passthrough
 162  */
 163 static int sbc_emulate_write_same(struct se_cmd *cmd)
 164 {
 165         struct se_device *dev = cmd->se_dev;
 166         sector_t range;
 167         sector_t lba = cmd->t_task_lba;
 168         u32 num_blocks;
 169         int ret;
 170
 171         if (!dev->transport->do_discard) {
 172                 pr_err("WRITE_SAME emulation not supported"
 173                                 " for: %s\n", dev->transport->name);
 174                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 175                 return -ENOSYS;
 176         }
 177
 178         if (cmd->t_task_cdb[0] == WRITE_SAME)
 179                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 180         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 181                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 182         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 183                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 184
 185         /*
 186          * Use the explicit range when non zero is supplied, otherwise calculate
 187          * the remaining range based on ->get_blocks() - starting LBA.
 188          */
 189         if (num_blocks != 0)
 190                 range = num_blocks;
 191         else
 192                 range = (dev->transport->get_blocks(dev) - lba) + 1;
 193
 194         pr_debug("WRITE_SAME UNMAP: LBA: %llu Range: %llu\n",
 195                  (unsigned long long)lba, (unsigned long long)range);
 196
 197         ret = dev->transport->do_discard(dev, lba, range);
 198         if (ret < 0) {
 199                 pr_debug("blkdev_issue_discard() failed for WRITE_SAME\n");
 200                 return ret;
 201         }
 202
 203         target_complete_cmd(cmd, GOOD);
 204         return 0;
 205 }
 206
 207 static int sbc_emulate_synchronize_cache(struct se_cmd *cmd)
 208 {
 209         if (!cmd->se_dev->transport->do_sync_cache) {
 210                 pr_err("SYNCHRONIZE_CACHE emulation not supported"
 211                         " for: %s\n", cmd->se_dev->transport->name);
 212                 cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 213                 return -ENOSYS;
 214         }
 215
 216         cmd->se_dev->transport->do_sync_cache(cmd);
 217         return 0;
 218 }
 219
 220 static int sbc_emulate_verify(struct se_cmd *cmd)
 221 {
 222         target_complete_cmd(cmd, GOOD);
 223         return 0;
 224 }
 225
 226 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 227 {
 228         return cmd->se_dev->se_sub_dev->se_dev_attrib.block_size * sectors;
 229 }
 230
 231 static int sbc_check_valid_sectors(struct se_cmd *cmd)
 232 {
 233         struct se_device *dev = cmd->se_dev;
 234         unsigned long long end_lba;
 235         u32 sectors;
 236
 237         sectors = cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size;
 238         end_lba = dev->transport->get_blocks(dev) + 1;
 239
 240         if (cmd->t_task_lba + sectors > end_lba) {
 241                 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
 242                         cmd->t_task_lba, sectors, end_lba);
 243                 return -EINVAL;
 244         }
 245
 246         return 0;
 247 }
 248
 249 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 250 {
 251         /*
 252          * Use 8-bit sector value.  SBC-3 says:
 253          *
 254          *   A TRANSFER LENGTH field set to zero specifies that 256
 255          *   logical blocks shall be written.  Any other value
 256          *   specifies the number of logical blocks that shall be
 257          *   written.
 258          */
 259         return cdb[4] ? : 256;
 260 }
 261
 262 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 263 {
 264         return (u32)(cdb[7] << 8) + cdb[8];
 265 }
 266
 267 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 268 {
 269         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 270 }
 271
 272 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 273 {
 274         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 275                     (cdb[12] << 8) + cdb[13];
 276 }
 277
 278 /*
 279  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 280  */
 281 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 282 {
 283         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 284                     (cdb[30] << 8) + cdb[31];
 285
 286 }
 287
 288 static inline u32 transport_lba_21(unsigned char *cdb)
 289 {
 290         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 291 }
 292
 293 static inline u32 transport_lba_32(unsigned char *cdb)
 294 {
 295         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 296 }
 297
 298 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 299 {
 300         unsigned int __v1, __v2;
 301
 302         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 303         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 304
 305         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 306 }
 307
 308 /*
 309  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 310  */
 311 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 312 {
 313         unsigned int __v1, __v2;
 314
 315         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 316         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 317
 318         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 319 }
 320
 321 static int sbc_write_same_supported(struct se_device *dev,
 322                 unsigned char *flags)
 323 {
 324         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 325                 pr_err("WRITE_SAME PBDATA and LBDATA"
 326                         " bits not supported for Block Discard"
 327                         " Emulation\n");
 328                 return -ENOSYS;
 329         }
 330
 331         /*
 332          * Currently for the emulated case we only accept
 333          * tpws with the UNMAP=1 bit set.
 334          */
 335         if (!(flags[0] & 0x08)) {
 336                 pr_err("WRITE_SAME w/o UNMAP bit not"
 337                         " supported for Block Discard Emulation\n");
 338                 return -ENOSYS;
 339         }
 340
 341         return 0;
 342 }
 343
 344 static void xdreadwrite_callback(struct se_cmd *cmd)
 345 {
 346         unsigned char *buf, *addr;
 347         struct scatterlist *sg;
 348         unsigned int offset;
 349         int i;
 350         int count;
 351         /*
 352          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 353          *
 354          * 1) read the specified logical block(s);
 355          * 2) transfer logical blocks from the data-out buffer;
 356          * 3) XOR the logical blocks transferred from the data-out buffer with
 357          *    the logical blocks read, storing the resulting XOR data in a buffer;
 358          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 359          *    blocks transferred from the data-out buffer; and
 360          * 5) transfer the resulting XOR data to the data-in buffer.
 361          */
 362         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 363         if (!buf) {
 364                 pr_err("Unable to allocate xor_callback buf\n");
 365                 return;
 366         }
 367         /*
 368          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 369          * into the locally allocated *buf
 370          */
 371         sg_copy_to_buffer(cmd->t_data_sg,
 372                           cmd->t_data_nents,
 373                           buf,
 374                           cmd->data_length);
 375
 376         /*
 377          * Now perform the XOR against the BIDI read memory located at
 378          * cmd->t_mem_bidi_list
 379          */
 380
 381         offset = 0;
 382         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 383                 addr = kmap_atomic(sg_page(sg));
 384                 if (!addr)
 385                         goto out;
 386
 387                 for (i = 0; i < sg->length; i++)
 388                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 389
 390                 offset += sg->length;
 391                 kunmap_atomic(addr);
 392         }
 393
 394 out:
 395         kfree(buf);
 396 }
 397
 398 int sbc_parse_cdb(struct se_cmd *cmd)
 399 {
 400         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
 401         struct se_device *dev = cmd->se_dev;
 402         unsigned char *cdb = cmd->t_task_cdb;
 403         unsigned int size;
 404         u32 sectors = 0;
 405         int ret;
 406
 407         switch (cdb[0]) {
 408         case READ_6:
 409                 sectors = transport_get_sectors_6(cdb);
 410                 cmd->t_task_lba = transport_lba_21(cdb);
 411                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 412                 break;
 413         case READ_10:
 414                 sectors = transport_get_sectors_10(cdb);
 415                 cmd->t_task_lba = transport_lba_32(cdb);
 416                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 417                 break;
 418         case READ_12:
 419                 sectors = transport_get_sectors_12(cdb);
 420                 cmd->t_task_lba = transport_lba_32(cdb);
 421                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 422                 break;
 423         case READ_16:
 424                 sectors = transport_get_sectors_16(cdb);
 425                 cmd->t_task_lba = transport_lba_64(cdb);
 426                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 427                 break;
 428         case WRITE_6:
 429                 sectors = transport_get_sectors_6(cdb);
 430                 cmd->t_task_lba = transport_lba_21(cdb);
 431                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 432                 break;
 433         case WRITE_10:
 434         case WRITE_VERIFY:
 435                 sectors = transport_get_sectors_10(cdb);
 436                 cmd->t_task_lba = transport_lba_32(cdb);
 437                 if (cdb[1] & 0x8)
 438                         cmd->se_cmd_flags |= SCF_FUA;
 439                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 440                 break;
 441         case WRITE_12:
 442                 sectors = transport_get_sectors_12(cdb);
 443                 cmd->t_task_lba = transport_lba_32(cdb);
 444                 if (cdb[1] & 0x8)
 445                         cmd->se_cmd_flags |= SCF_FUA;
 446                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 447                 break;
 448         case WRITE_16:
 449                 sectors = transport_get_sectors_16(cdb);
 450                 cmd->t_task_lba = transport_lba_64(cdb);
 451                 if (cdb[1] & 0x8)
 452                         cmd->se_cmd_flags |= SCF_FUA;
 453                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 454                 break;
 455         case XDWRITEREAD_10:
 456                 if ((cmd->data_direction != DMA_TO_DEVICE) ||
 457                     !(cmd->se_cmd_flags & SCF_BIDI))
 458                         goto out_invalid_cdb_field;
 459                 sectors = transport_get_sectors_10(cdb);
 460
 461                 cmd->t_task_lba = transport_lba_32(cdb);
 462                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 463
 464                 /*
 465                  * Setup BIDI XOR callback to be run after I/O completion.
 466                  */
 467                 cmd->transport_complete_callback = &xdreadwrite_callback;
 468                 if (cdb[1] & 0x8)
 469                         cmd->se_cmd_flags |= SCF_FUA;
 470                 break;
 471         case VARIABLE_LENGTH_CMD:
 472         {
 473                 u16 service_action = get_unaligned_be16(&cdb[8]);
 474                 switch (service_action) {
 475                 case XDWRITEREAD_32:
 476                         sectors = transport_get_sectors_32(cdb);
 477
 478                         /*
 479                          * Use WRITE_32 and READ_32 opcodes for the emulated
 480                          * XDWRITE_READ_32 logic.
 481                          */
 482                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 483                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 484
 485                         /*
 486                          * Setup BIDI XOR callback to be run during after I/O
 487                          * completion.
 488                          */
 489                         cmd->transport_complete_callback = &xdreadwrite_callback;
 490                         if (cdb[1] & 0x8)
 491                                 cmd->se_cmd_flags |= SCF_FUA;
 492                         break;
 493                 case WRITE_SAME_32:
 494                         sectors = transport_get_sectors_32(cdb);
 495                         if (!sectors) {
 496                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 497                                        " supported\n");
 498                                 goto out_invalid_cdb_field;
 499                         }
 500
 501                         size = sbc_get_size(cmd, 1);
 502                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 503
 504                         if (sbc_write_same_supported(dev, &cdb[10]) < 0)
 505                                 goto out_unsupported_cdb;
 506                         cmd->execute_cmd = sbc_emulate_write_same;
 507                         break;
 508                 default:
 509                         pr_err("VARIABLE_LENGTH_CMD service action"
 510                                 " 0x%04x not supported\n", service_action);
 511                         goto out_unsupported_cdb;
 512                 }
 513                 break;
 514         }
 515         case READ_CAPACITY:
 516                 size = READ_CAP_LEN;
 517                 cmd->execute_cmd = sbc_emulate_readcapacity;
 518                 break;
 519         case SERVICE_ACTION_IN:
 520                 switch (cmd->t_task_cdb[1] & 0x1f) {
 521                 case SAI_READ_CAPACITY_16:
 522                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 523                         break;
 524                 default:
 525                         pr_err("Unsupported SA: 0x%02x\n",
 526                                 cmd->t_task_cdb[1] & 0x1f);
 527                         goto out_invalid_cdb_field;
 528                 }
 529                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 530                        (cdb[12] << 8) | cdb[13];
 531                 break;
 532         case SYNCHRONIZE_CACHE:
 533         case SYNCHRONIZE_CACHE_16:
 534                 /*
 535                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
 536                  */
 537                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 538                         sectors = transport_get_sectors_10(cdb);
 539                         cmd->t_task_lba = transport_lba_32(cdb);
 540                 } else {
 541                         sectors = transport_get_sectors_16(cdb);
 542                         cmd->t_task_lba = transport_lba_64(cdb);
 543                 }
 544
 545                 size = sbc_get_size(cmd, sectors);
 546
 547                 /*
 548                  * Check to ensure that LBA + Range does not exceed past end of
 549                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
 550                  */
 551                 if (cmd->t_task_lba || sectors) {
 552                         if (sbc_check_valid_sectors(cmd) < 0)
 553                                 goto out_invalid_cdb_field;
 554                 }
 555                 cmd->execute_cmd = sbc_emulate_synchronize_cache;
 556                 break;
 557         case UNMAP:
 558                 size = get_unaligned_be16(&cdb[7]);
 559                 cmd->execute_cmd = sbc_emulate_unmap;
 560                 break;
 561         case WRITE_SAME_16:
 562                 sectors = transport_get_sectors_16(cdb);
 563                 if (!sectors) {
 564                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 565                         goto out_invalid_cdb_field;
 566                 }
 567
 568                 size = sbc_get_size(cmd, 1);
 569                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 570
 571                 if (sbc_write_same_supported(dev, &cdb[1]) < 0)
 572                         goto out_unsupported_cdb;
 573                 cmd->execute_cmd = sbc_emulate_write_same;
 574                 break;
 575         case WRITE_SAME:
 576                 sectors = transport_get_sectors_10(cdb);
 577                 if (!sectors) {
 578                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 579                         goto out_invalid_cdb_field;
 580                 }
 581
 582                 size = sbc_get_size(cmd, 1);
 583                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 584
 585                 /*
 586                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 587                  * of byte 1 bit 3 UNMAP instead of original reserved field
 588                  */
 589                 if (sbc_write_same_supported(dev, &cdb[1]) < 0)
 590                         goto out_unsupported_cdb;
 591                 cmd->execute_cmd = sbc_emulate_write_same;
 592                 break;
 593         case VERIFY:
 594                 size = 0;
 595                 cmd->execute_cmd = sbc_emulate_verify;
 596                 break;
 597         default:
 598                 ret = spc_parse_cdb(cmd, &size);
 599                 if (ret)
 600                         return ret;
 601         }
 602
 603         /* reject any command that we don't have a handler for */
 604         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
 605                 goto out_unsupported_cdb;
 606
 607         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 608                 unsigned long long end_lba;
 609
 610                 if (sectors > su_dev->se_dev_attrib.fabric_max_sectors) {
 611                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 612                                 " big sectors %u exceeds fabric_max_sectors:"
 613                                 " %u\n", cdb[0], sectors,
 614                                 su_dev->se_dev_attrib.fabric_max_sectors);
 615                         goto out_invalid_cdb_field;
 616                 }
 617                 if (sectors > su_dev->se_dev_attrib.hw_max_sectors) {
 618                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 619                                 " big sectors %u exceeds backend hw_max_sectors:"
 620                                 " %u\n", cdb[0], sectors,
 621                                 su_dev->se_dev_attrib.hw_max_sectors);
 622                         goto out_invalid_cdb_field;
 623                 }
 624
 625                 end_lba = dev->transport->get_blocks(dev) + 1;
 626                 if (cmd->t_task_lba + sectors > end_lba) {
 627                         pr_err("cmd exceeds last lba %llu "
 628                                 "(lba %llu, sectors %u)\n",
 629                                 end_lba, cmd->t_task_lba, sectors);
 630                         goto out_invalid_cdb_field;
 631                 }
 632
 633                 size = sbc_get_size(cmd, sectors);
 634         }
 635
 636         ret = target_cmd_size_check(cmd, size);
 637         if (ret < 0)
 638                 return ret;
 639
 640         return 0;
 641
 642 out_unsupported_cdb:
 643         cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
 644         cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 645         return -EINVAL;
 646 out_invalid_cdb_field:
 647         cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
 648         cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
 649         return -EINVAL;
 650 }
 651 EXPORT_SYMBOL(sbc_parse_cdb);