Pileus Git - ~andy/linux/blob - 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 long long blocks_long = dev->transport->get_blocks(dev);
  44         unsigned char *rbuf;
  45         unsigned char buf[8];
  46         u32 blocks;
  47
  48         if (blocks_long >= 0x00000000ffffffff)
  49                 blocks = 0xffffffff;
  50         else
  51                 blocks = (u32)blocks_long;
  52
  53         buf[0] = (blocks >> 24) & 0xff;
  54         buf[1] = (blocks >> 16) & 0xff;
  55         buf[2] = (blocks >> 8) & 0xff;
  56         buf[3] = blocks & 0xff;
  57         buf[4] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
  58         buf[5] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
  59         buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
  60         buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
  61
  62         rbuf = transport_kmap_data_sg(cmd);
  63         if (rbuf) {
  64                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  65                 transport_kunmap_data_sg(cmd);
  66         }
  67
  68         target_complete_cmd(cmd, GOOD);
  69         return 0;
  70 }
  71
  72 static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  73 {
  74         struct se_device *dev = cmd->se_dev;
  75         unsigned char *rbuf;
  76         unsigned char buf[32];
  77         unsigned long long blocks = dev->transport->get_blocks(dev);
  78
  79         memset(buf, 0, sizeof(buf));
  80         buf[0] = (blocks >> 56) & 0xff;
  81         buf[1] = (blocks >> 48) & 0xff;
  82         buf[2] = (blocks >> 40) & 0xff;
  83         buf[3] = (blocks >> 32) & 0xff;
  84         buf[4] = (blocks >> 24) & 0xff;
  85         buf[5] = (blocks >> 16) & 0xff;
  86         buf[6] = (blocks >> 8) & 0xff;
  87         buf[7] = blocks & 0xff;
  88         buf[8] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
  89         buf[9] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
  90         buf[10] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
  91         buf[11] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
  92         /*
  93          * Set Thin Provisioning Enable bit following sbc3r22 in section
  94          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
  95          */
  96         if (dev->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws)
  97                 buf[14] = 0x80;
  98
  99         rbuf = transport_kmap_data_sg(cmd);
 100         if (rbuf) {
 101                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 102                 transport_kunmap_data_sg(cmd);
 103         }
 104
 105         target_complete_cmd(cmd, GOOD);
 106         return 0;
 107 }
 108
 109 int spc_get_write_same_sectors(struct se_cmd *cmd)
 110 {
 111         u32 num_blocks;
 112
 113         if (cmd->t_task_cdb[0] == WRITE_SAME)
 114                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 115         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 116                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 117         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 118                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 119
 120         /*
 121          * Use the explicit range when non zero is supplied, otherwise calculate
 122          * the remaining range based on ->get_blocks() - starting LBA.
 123          */
 124         if (num_blocks)
 125                 return num_blocks;
 126
 127         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 128                 cmd->t_task_lba + 1;
 129 }
 130 EXPORT_SYMBOL(spc_get_write_same_sectors);
 131
 132 static int sbc_emulate_verify(struct se_cmd *cmd)
 133 {
 134         target_complete_cmd(cmd, GOOD);
 135         return 0;
 136 }
 137
 138 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 139 {
 140         return cmd->se_dev->se_sub_dev->se_dev_attrib.block_size * sectors;
 141 }
 142
 143 static int sbc_check_valid_sectors(struct se_cmd *cmd)
 144 {
 145         struct se_device *dev = cmd->se_dev;
 146         unsigned long long end_lba;
 147         u32 sectors;
 148
 149         sectors = cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size;
 150         end_lba = dev->transport->get_blocks(dev) + 1;
 151
 152         if (cmd->t_task_lba + sectors > end_lba) {
 153                 pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
 154                         cmd->t_task_lba, sectors, end_lba);
 155                 return -EINVAL;
 156         }
 157
 158         return 0;
 159 }
 160
 161 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 162 {
 163         /*
 164          * Use 8-bit sector value.  SBC-3 says:
 165          *
 166          *   A TRANSFER LENGTH field set to zero specifies that 256
 167          *   logical blocks shall be written.  Any other value
 168          *   specifies the number of logical blocks that shall be
 169          *   written.
 170          */
 171         return cdb[4] ? : 256;
 172 }
 173
 174 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 175 {
 176         return (u32)(cdb[7] << 8) + cdb[8];
 177 }
 178
 179 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 180 {
 181         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 182 }
 183
 184 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 185 {
 186         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 187                     (cdb[12] << 8) + cdb[13];
 188 }
 189
 190 /*
 191  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 192  */
 193 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 194 {
 195         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 196                     (cdb[30] << 8) + cdb[31];
 197
 198 }
 199
 200 static inline u32 transport_lba_21(unsigned char *cdb)
 201 {
 202         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 203 }
 204
 205 static inline u32 transport_lba_32(unsigned char *cdb)
 206 {
 207         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 208 }
 209
 210 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 211 {
 212         unsigned int __v1, __v2;
 213
 214         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 215         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 216
 217         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 218 }
 219
 220 /*
 221  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 222  */
 223 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 224 {
 225         unsigned int __v1, __v2;
 226
 227         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 228         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 229
 230         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 231 }
 232
 233 static int sbc_write_same_supported(struct se_device *dev,
 234                 unsigned char *flags)
 235 {
 236         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 237                 pr_err("WRITE_SAME PBDATA and LBDATA"
 238                         " bits not supported for Block Discard"
 239                         " Emulation\n");
 240                 return -ENOSYS;
 241         }
 242
 243         /*
 244          * Currently for the emulated case we only accept
 245          * tpws with the UNMAP=1 bit set.
 246          */
 247         if (!(flags[0] & 0x08)) {
 248                 pr_err("WRITE_SAME w/o UNMAP bit not"
 249                         " supported for Block Discard Emulation\n");
 250                 return -ENOSYS;
 251         }
 252
 253         return 0;
 254 }
 255
 256 static void xdreadwrite_callback(struct se_cmd *cmd)
 257 {
 258         unsigned char *buf, *addr;
 259         struct scatterlist *sg;
 260         unsigned int offset;
 261         int i;
 262         int count;
 263         /*
 264          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 265          *
 266          * 1) read the specified logical block(s);
 267          * 2) transfer logical blocks from the data-out buffer;
 268          * 3) XOR the logical blocks transferred from the data-out buffer with
 269          *    the logical blocks read, storing the resulting XOR data in a buffer;
 270          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 271          *    blocks transferred from the data-out buffer; and
 272          * 5) transfer the resulting XOR data to the data-in buffer.
 273          */
 274         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 275         if (!buf) {
 276                 pr_err("Unable to allocate xor_callback buf\n");
 277                 return;
 278         }
 279         /*
 280          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 281          * into the locally allocated *buf
 282          */
 283         sg_copy_to_buffer(cmd->t_data_sg,
 284                           cmd->t_data_nents,
 285                           buf,
 286                           cmd->data_length);
 287
 288         /*
 289          * Now perform the XOR against the BIDI read memory located at
 290          * cmd->t_mem_bidi_list
 291          */
 292
 293         offset = 0;
 294         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 295                 addr = kmap_atomic(sg_page(sg));
 296                 if (!addr)
 297                         goto out;
 298
 299                 for (i = 0; i < sg->length; i++)
 300                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 301
 302                 offset += sg->length;
 303                 kunmap_atomic(addr);
 304         }
 305
 306 out:
 307         kfree(buf);
 308 }
 309
 310 int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
 311 {
 312         struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
 313         struct se_device *dev = cmd->se_dev;
 314         unsigned char *cdb = cmd->t_task_cdb;
 315         unsigned int size;
 316         u32 sectors = 0;
 317         int ret;
 318
 319         switch (cdb[0]) {
 320         case READ_6:
 321                 sectors = transport_get_sectors_6(cdb);
 322                 cmd->t_task_lba = transport_lba_21(cdb);
 323                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 324                 cmd->execute_cmd = ops->execute_rw;
 325                 break;
 326         case READ_10:
 327                 sectors = transport_get_sectors_10(cdb);
 328                 cmd->t_task_lba = transport_lba_32(cdb);
 329                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 330                 cmd->execute_cmd = ops->execute_rw;
 331                 break;
 332         case READ_12:
 333                 sectors = transport_get_sectors_12(cdb);
 334                 cmd->t_task_lba = transport_lba_32(cdb);
 335                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 336                 cmd->execute_cmd = ops->execute_rw;
 337                 break;
 338         case READ_16:
 339                 sectors = transport_get_sectors_16(cdb);
 340                 cmd->t_task_lba = transport_lba_64(cdb);
 341                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 342                 cmd->execute_cmd = ops->execute_rw;
 343                 break;
 344         case WRITE_6:
 345                 sectors = transport_get_sectors_6(cdb);
 346                 cmd->t_task_lba = transport_lba_21(cdb);
 347                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 348                 cmd->execute_cmd = ops->execute_rw;
 349                 break;
 350         case WRITE_10:
 351         case WRITE_VERIFY:
 352                 sectors = transport_get_sectors_10(cdb);
 353                 cmd->t_task_lba = transport_lba_32(cdb);
 354                 if (cdb[1] & 0x8)
 355                         cmd->se_cmd_flags |= SCF_FUA;
 356                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 357                 cmd->execute_cmd = ops->execute_rw;
 358                 break;
 359         case WRITE_12:
 360                 sectors = transport_get_sectors_12(cdb);
 361                 cmd->t_task_lba = transport_lba_32(cdb);
 362                 if (cdb[1] & 0x8)
 363                         cmd->se_cmd_flags |= SCF_FUA;
 364                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 365                 cmd->execute_cmd = ops->execute_rw;
 366                 break;
 367         case WRITE_16:
 368                 sectors = transport_get_sectors_16(cdb);
 369                 cmd->t_task_lba = transport_lba_64(cdb);
 370                 if (cdb[1] & 0x8)
 371                         cmd->se_cmd_flags |= SCF_FUA;
 372                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 373                 cmd->execute_cmd = ops->execute_rw;
 374                 break;
 375         case XDWRITEREAD_10:
 376                 if ((cmd->data_direction != DMA_TO_DEVICE) ||
 377                     !(cmd->se_cmd_flags & SCF_BIDI))
 378                         goto out_invalid_cdb_field;
 379                 sectors = transport_get_sectors_10(cdb);
 380
 381                 cmd->t_task_lba = transport_lba_32(cdb);
 382                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 383
 384                 /*
 385                  * Setup BIDI XOR callback to be run after I/O completion.
 386                  */
 387                 cmd->execute_cmd = ops->execute_rw;
 388                 cmd->transport_complete_callback = &xdreadwrite_callback;
 389                 if (cdb[1] & 0x8)
 390                         cmd->se_cmd_flags |= SCF_FUA;
 391                 break;
 392         case VARIABLE_LENGTH_CMD:
 393         {
 394                 u16 service_action = get_unaligned_be16(&cdb[8]);
 395                 switch (service_action) {
 396                 case XDWRITEREAD_32:
 397                         sectors = transport_get_sectors_32(cdb);
 398
 399                         /*
 400                          * Use WRITE_32 and READ_32 opcodes for the emulated
 401                          * XDWRITE_READ_32 logic.
 402                          */
 403                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 404                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 405
 406                         /*
 407                          * Setup BIDI XOR callback to be run during after I/O
 408                          * completion.
 409                          */
 410                         cmd->execute_cmd = ops->execute_rw;
 411                         cmd->transport_complete_callback = &xdreadwrite_callback;
 412                         if (cdb[1] & 0x8)
 413                                 cmd->se_cmd_flags |= SCF_FUA;
 414                         break;
 415                 case WRITE_SAME_32:
 416                         if (!ops->execute_write_same)
 417                                 goto out_unsupported_cdb;
 418
 419                         sectors = transport_get_sectors_32(cdb);
 420                         if (!sectors) {
 421                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 422                                        " supported\n");
 423                                 goto out_invalid_cdb_field;
 424                         }
 425
 426                         size = sbc_get_size(cmd, 1);
 427                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 428
 429                         if (sbc_write_same_supported(dev, &cdb[10]) < 0)
 430                                 goto out_unsupported_cdb;
 431                         cmd->execute_cmd = ops->execute_write_same;
 432                         break;
 433                 default:
 434                         pr_err("VARIABLE_LENGTH_CMD service action"
 435                                 " 0x%04x not supported\n", service_action);
 436                         goto out_unsupported_cdb;
 437                 }
 438                 break;
 439         }
 440         case READ_CAPACITY:
 441                 size = READ_CAP_LEN;
 442                 cmd->execute_cmd = sbc_emulate_readcapacity;
 443                 break;
 444         case SERVICE_ACTION_IN:
 445                 switch (cmd->t_task_cdb[1] & 0x1f) {
 446                 case SAI_READ_CAPACITY_16:
 447                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 448                         break;
 449                 default:
 450                         pr_err("Unsupported SA: 0x%02x\n",
 451                                 cmd->t_task_cdb[1] & 0x1f);
 452                         goto out_invalid_cdb_field;
 453                 }
 454                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 455                        (cdb[12] << 8) | cdb[13];
 456                 break;
 457         case SYNCHRONIZE_CACHE:
 458         case SYNCHRONIZE_CACHE_16:
 459                 if (!ops->execute_sync_cache)
 460                         goto out_unsupported_cdb;
 461
 462                 /*
 463                  * Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
 464                  */
 465                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 466                         sectors = transport_get_sectors_10(cdb);
 467                         cmd->t_task_lba = transport_lba_32(cdb);
 468                 } else {
 469                         sectors = transport_get_sectors_16(cdb);
 470                         cmd->t_task_lba = transport_lba_64(cdb);
 471                 }
 472
 473                 size = sbc_get_size(cmd, sectors);
 474
 475                 /*
 476                  * Check to ensure that LBA + Range does not exceed past end of
 477                  * device for IBLOCK and FILEIO ->do_sync_cache() backend calls
 478                  */
 479                 if (cmd->t_task_lba || sectors) {
 480                         if (sbc_check_valid_sectors(cmd) < 0)
 481                                 goto out_invalid_cdb_field;
 482                 }
 483                 cmd->execute_cmd = ops->execute_sync_cache;
 484                 break;
 485         case UNMAP:
 486                 if (!ops->execute_unmap)
 487                         goto out_unsupported_cdb;
 488
 489                 size = get_unaligned_be16(&cdb[7]);
 490                 cmd->execute_cmd = ops->execute_unmap;
 491                 break;
 492         case WRITE_SAME_16:
 493                 if (!ops->execute_write_same)
 494                         goto out_unsupported_cdb;
 495
 496                 sectors = transport_get_sectors_16(cdb);
 497                 if (!sectors) {
 498                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 499                         goto out_invalid_cdb_field;
 500                 }
 501
 502                 size = sbc_get_size(cmd, 1);
 503                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 504
 505                 if (sbc_write_same_supported(dev, &cdb[1]) < 0)
 506                         goto out_unsupported_cdb;
 507                 cmd->execute_cmd = ops->execute_write_same;
 508                 break;
 509         case WRITE_SAME:
 510                 if (!ops->execute_write_same)
 511                         goto out_unsupported_cdb;
 512
 513                 sectors = transport_get_sectors_10(cdb);
 514                 if (!sectors) {
 515                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 516                         goto out_invalid_cdb_field;
 517                 }
 518
 519                 size = sbc_get_size(cmd, 1);
 520                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 521
 522                 /*
 523                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 524                  * of byte 1 bit 3 UNMAP instead of original reserved field
 525                  */
 526                 if (sbc_write_same_supported(dev, &cdb[1]) < 0)
 527                         goto out_unsupported_cdb;
 528                 cmd->execute_cmd = ops->execute_write_same;
 529                 break;
 530         case VERIFY:
 531                 size = 0;
 532                 cmd->execute_cmd = sbc_emulate_verify;
 533                 break;
 534         default:
 535                 ret = spc_parse_cdb(cmd, &size);
 536                 if (ret)
 537                         return ret;
 538         }
 539
 540         /* reject any command that we don't have a handler for */
 541         if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
 542                 goto out_unsupported_cdb;
 543
 544         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
 545                 unsigned long long end_lba;
 546
 547                 if (sectors > su_dev->se_dev_attrib.fabric_max_sectors) {
 548                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 549                                 " big sectors %u exceeds fabric_max_sectors:"
 550                                 " %u\n", cdb[0], sectors,
 551                                 su_dev->se_dev_attrib.fabric_max_sectors);
 552                         goto out_invalid_cdb_field;
 553                 }
 554                 if (sectors > su_dev->se_dev_attrib.hw_max_sectors) {
 555                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
 556                                 " big sectors %u exceeds backend hw_max_sectors:"
 557                                 " %u\n", cdb[0], sectors,
 558                                 su_dev->se_dev_attrib.hw_max_sectors);
 559                         goto out_invalid_cdb_field;
 560                 }
 561
 562                 end_lba = dev->transport->get_blocks(dev) + 1;
 563                 if (cmd->t_task_lba + sectors > end_lba) {
 564                         pr_err("cmd exceeds last lba %llu "
 565                                 "(lba %llu, sectors %u)\n",
 566                                 end_lba, cmd->t_task_lba, sectors);
 567                         goto out_invalid_cdb_field;
 568                 }
 569
 570                 size = sbc_get_size(cmd, sectors);
 571         }
 572
 573         ret = target_cmd_size_check(cmd, size);
 574         if (ret < 0)
 575                 return ret;
 576
 577         return 0;
 578
 579 out_unsupported_cdb:
 580         cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
 581         cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
 582         return -EINVAL;
 583 out_invalid_cdb_field:
 584         cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
 585         cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
 586         return -EINVAL;
 587 }
 588 EXPORT_SYMBOL(sbc_parse_cdb);